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MATHEMATICS (651 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 538 Journals sorted alphabetically
Abakós     Open Access   (Followers: 3)
Abhandlungen aus dem Mathematischen Seminar der Universitat Hamburg     Hybrid Journal   (Followers: 2)
Academic Voices : A Multidisciplinary Journal     Open Access   (Followers: 2)
Accounting Perspectives     Full-text available via subscription   (Followers: 8)
ACM Transactions on Algorithms (TALG)     Hybrid Journal   (Followers: 16)
ACM Transactions on Computational Logic (TOCL)     Hybrid Journal   (Followers: 4)
ACM Transactions on Mathematical Software (TOMS)     Hybrid Journal   (Followers: 6)
ACS Applied Materials & Interfaces     Full-text available via subscription   (Followers: 21)
Acta Applicandae Mathematicae     Hybrid Journal   (Followers: 1)
Acta Mathematica     Hybrid Journal   (Followers: 11)
Acta Mathematica Hungarica     Hybrid Journal   (Followers: 2)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5)
Acta Mathematica Sinica, English Series     Hybrid Journal   (Followers: 5)
Acta Mathematica Vietnamica     Hybrid Journal  
Acta Mathematicae Applicatae Sinica, English Series     Hybrid Journal  
Advanced Science Letters     Full-text available via subscription   (Followers: 7)
Advances in Applied Clifford Algebras     Hybrid Journal   (Followers: 3)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 15)
Advances in Decision Sciences     Open Access   (Followers: 4)
Advances in Difference Equations     Open Access   (Followers: 1)
Advances in Fixed Point Theory     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 10)
Advances in Linear Algebra & Matrix Theory     Open Access   (Followers: 1)
Advances in Materials Sciences     Open Access   (Followers: 16)
Advances in Mathematical Physics     Open Access   (Followers: 5)
Advances in Mathematics     Full-text available via subscription   (Followers: 10)
Advances in Numerical Analysis     Open Access   (Followers: 4)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Pure and Applied Mathematics     Hybrid Journal   (Followers: 5)
Advances in Pure Mathematics     Open Access   (Followers: 4)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aequationes Mathematicae     Hybrid Journal   (Followers: 2)
African Journal of Educational Studies in Mathematics and Sciences     Full-text available via subscription   (Followers: 5)
African Journal of Mathematics and Computer Science Research     Open Access   (Followers: 4)
Afrika Matematika     Hybrid Journal   (Followers: 1)
Air, Soil & Water Research     Open Access   (Followers: 7)
AKSIOMA Journal of Mathematics Education     Open Access   (Followers: 1)
Algebra and Logic     Hybrid Journal   (Followers: 3)
Algebra Colloquium     Hybrid Journal   (Followers: 4)
Algebra Universalis     Hybrid Journal   (Followers: 2)
Algorithmic Operations Research     Full-text available via subscription   (Followers: 5)
Algorithms     Open Access   (Followers: 11)
Algorithms Research     Open Access   (Followers: 1)
American Journal of Biostatistics     Open Access   (Followers: 9)
American Journal of Computational and Applied Mathematics     Open Access   (Followers: 4)
American Journal of Mathematical Analysis     Open Access  
American Journal of Mathematics     Full-text available via subscription   (Followers: 7)
American Journal of Operations Research     Open Access   (Followers: 5)
American Mathematical Monthly     Full-text available via subscription   (Followers: 6)
An International Journal of Optimization and Control: Theories & Applications     Open Access   (Followers: 7)
Analele Universitatii Ovidius Constanta - Seria Matematica     Open Access   (Followers: 1)
Analysis     Hybrid Journal   (Followers: 2)
Analysis and Applications     Hybrid Journal   (Followers: 1)
Analysis and Mathematical Physics     Hybrid Journal   (Followers: 3)
Analysis Mathematica     Full-text available via subscription  
Annales Mathematicae Silesianae     Open Access  
Annales mathématiques du Québec     Hybrid Journal   (Followers: 4)
Annales UMCS, Mathematica     Open Access   (Followers: 1)
Annales Universitatis Paedagogicae Cracoviensis. Studia Mathematica     Open Access  
Annali di Matematica Pura ed Applicata     Hybrid Journal   (Followers: 1)
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Data Science     Hybrid Journal   (Followers: 9)
Annals of Discrete Mathematics     Full-text available via subscription   (Followers: 6)
Annals of Mathematics     Full-text available via subscription  
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 6)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of the Alexandru Ioan Cuza University - Mathematics     Open Access  
Annals of the Institute of Statistical Mathematics     Hybrid Journal   (Followers: 1)
Annals of West University of Timisoara - Mathematics     Open Access  
Annuaire du Collège de France     Open Access   (Followers: 5)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applications of Mathematics     Hybrid Journal   (Followers: 1)
Applied Categorical Structures     Hybrid Journal   (Followers: 2)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Mathematics     Open Access   (Followers: 3)
Applied Mathematics     Open Access   (Followers: 4)
Applied Mathematics & Optimization     Hybrid Journal   (Followers: 4)
Applied Mathematics - A Journal of Chinese Universities     Hybrid Journal  
Applied Mathematics Letters     Full-text available via subscription   (Followers: 1)
Applied Mathematics Research eXpress     Hybrid Journal   (Followers: 1)
Applied Network Science     Open Access  
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Arab Journal of Mathematical Sciences     Open Access   (Followers: 2)
Arabian Journal of Mathematics     Open Access   (Followers: 2)
Archive for Mathematical Logic     Hybrid Journal   (Followers: 1)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 4)
Archive of Numerical Software     Open Access  
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
Arnold Mathematical Journal     Hybrid Journal   (Followers: 1)
Artificial Satellites : The Journal of Space Research Centre of Polish Academy of Sciences     Open Access   (Followers: 19)
Asia-Pacific Journal of Operational Research     Hybrid Journal   (Followers: 3)
Asian Journal of Algebra     Open Access   (Followers: 1)
Asian Journal of Current Engineering & Maths     Open Access  
Asian-European Journal of Mathematics     Hybrid Journal   (Followers: 2)
Australian Mathematics Teacher, The     Full-text available via subscription   (Followers: 7)
Australian Primary Mathematics Classroom     Full-text available via subscription   (Followers: 2)
Australian Senior Mathematics Journal     Full-text available via subscription   (Followers: 1)
Automatic Documentation and Mathematical Linguistics     Hybrid Journal   (Followers: 5)
Axioms     Open Access  
Baltic International Yearbook of Cognition, Logic and Communication     Open Access  
Basin Research     Hybrid Journal   (Followers: 5)
BIBECHANA     Open Access  
BIT Numerical Mathematics     Hybrid Journal  
BoEM - Boletim online de Educação Matemática     Open Access  
Boletim Cearense de Educação e História da Matemática     Open Access  
Boletim de Educação Matemática     Open Access  
Boletín de la Sociedad Matemática Mexicana     Hybrid Journal  
Bollettino dell'Unione Matematica Italiana     Full-text available via subscription   (Followers: 1)
British Journal of Mathematical and Statistical Psychology     Full-text available via subscription   (Followers: 21)
Bruno Pini Mathematical Analysis Seminar     Open Access  
Buletinul Academiei de Stiinte a Republicii Moldova. Matematica     Open Access   (Followers: 7)
Bulletin des Sciences Mathamatiques     Full-text available via subscription   (Followers: 4)
Bulletin of Dnipropetrovsk University. Series : Communications in Mathematical Modeling and Differential Equations Theory     Open Access   (Followers: 1)
Bulletin of Mathematical Sciences     Open Access   (Followers: 1)
Bulletin of the Brazilian Mathematical Society, New Series     Hybrid Journal  
Bulletin of the London Mathematical Society     Hybrid Journal   (Followers: 3)
Bulletin of the Malaysian Mathematical Sciences Society     Hybrid Journal  
Calculus of Variations and Partial Differential Equations     Hybrid Journal  
Canadian Journal of Science, Mathematics and Technology Education     Hybrid Journal   (Followers: 18)
Carpathian Mathematical Publications     Open Access   (Followers: 1)
Catalysis in Industry     Hybrid Journal   (Followers: 1)
CEAS Space Journal     Hybrid Journal  
CHANCE     Hybrid Journal   (Followers: 5)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
ChemSusChem     Hybrid Journal   (Followers: 7)
Chinese Annals of Mathematics, Series B     Hybrid Journal  
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Mathematics     Open Access  
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Cogent Mathematics     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Collectanea Mathematica     Hybrid Journal  
College Mathematics Journal     Full-text available via subscription   (Followers: 2)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Commentarii Mathematici Helvetici     Hybrid Journal   (Followers: 1)
Communications in Contemporary Mathematics     Hybrid Journal  
Communications in Mathematical Physics     Hybrid Journal   (Followers: 1)
Communications On Pure & Applied Mathematics     Hybrid Journal   (Followers: 3)
Complex Analysis and its Synergies     Open Access   (Followers: 2)
Complex Variables and Elliptic Equations: An International Journal     Hybrid Journal  
Complexus     Full-text available via subscription  
Composite Materials Series     Full-text available via subscription   (Followers: 9)
Comptes Rendus Mathematique     Full-text available via subscription   (Followers: 1)
Computational and Applied Mathematics     Hybrid Journal   (Followers: 2)
Computational and Mathematical Methods in Medicine     Open Access   (Followers: 2)
Computational and Mathematical Organization Theory     Hybrid Journal   (Followers: 2)
Computational Complexity     Hybrid Journal   (Followers: 4)
Computational Mathematics and Modeling     Hybrid Journal   (Followers: 8)
Computational Mechanics     Hybrid Journal   (Followers: 4)
Computational Methods and Function Theory     Hybrid Journal  
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 5)
Concrete Operators     Open Access   (Followers: 4)
Confluentes Mathematici     Hybrid Journal  
COSMOS     Hybrid Journal  
Cryptography and Communications     Hybrid Journal   (Followers: 14)
Cuadernos de Investigación y Formación en Educación Matemática     Open Access  
Cubo. A Mathematical Journal     Open Access  
Czechoslovak Mathematical Journal     Hybrid Journal   (Followers: 1)
Demographic Research     Open Access   (Followers: 11)
Demonstratio Mathematica     Open Access  
Dependence Modeling     Open Access  
Design Journal : An International Journal for All Aspects of Design     Hybrid Journal   (Followers: 29)
Developments in Clay Science     Full-text available via subscription   (Followers: 1)
Developments in Mineral Processing     Full-text available via subscription   (Followers: 3)
Dhaka University Journal of Science     Open Access  
Differential Equations and Dynamical Systems     Hybrid Journal   (Followers: 2)
Discrete Mathematics     Hybrid Journal   (Followers: 7)
Discrete Mathematics & Theoretical Computer Science     Open Access  
Discrete Mathematics, Algorithms and Applications     Hybrid Journal   (Followers: 2)
Discussiones Mathematicae Graph Theory     Open Access   (Followers: 1)
Dnipropetrovsk University Mathematics Bulletin     Open Access  
Doklady Mathematics     Hybrid Journal  
Duke Mathematical Journal     Full-text available via subscription   (Followers: 1)
Edited Series on Advances in Nonlinear Science and Complexity     Full-text available via subscription  
Electronic Journal of Graph Theory and Applications     Open Access   (Followers: 2)
Electronic Notes in Discrete Mathematics     Full-text available via subscription   (Followers: 2)
Elemente der Mathematik     Full-text available via subscription   (Followers: 3)
Energy for Sustainable Development     Hybrid Journal   (Followers: 9)
Enseñanza de las Ciencias : Revista de Investigación y Experiencias Didácticas     Open Access  
Ensino da Matemática em Debate     Open Access  
Entropy     Open Access   (Followers: 5)
ESAIM: Control Optimisation and Calculus of Variations     Full-text available via subscription   (Followers: 1)
European Journal of Combinatorics     Full-text available via subscription   (Followers: 4)
European Journal of Mathematics     Hybrid Journal   (Followers: 1)
European Scientific Journal     Open Access   (Followers: 2)
Experimental Mathematics     Hybrid Journal   (Followers: 4)
Expositiones Mathematicae     Hybrid Journal   (Followers: 2)
Facta Universitatis, Series : Mathematics and Informatics     Open Access  
Fasciculi Mathematici     Open Access  
Finite Fields and Their Applications     Full-text available via subscription   (Followers: 4)
Fixed Point Theory and Applications     Open Access   (Followers: 1)
Formalized Mathematics     Open Access   (Followers: 2)

        1 2 3 4 | Last

Journal Cover ChemSusChem
  [SJR: 2.649]   [H-I: 88]   [7 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1864-5631 - ISSN (Online) 1864-564X
   Published by John Wiley and Sons Homepage  [1577 journals]
  • A New Energy-Saving Catalytic System: CO2 Activation via Metal/Carbon
    • Authors: Danim Yun; Dae Sung Park, Kyung Rok Lee, Yang Sik Yun, Tae Yong Kim, Hongseok Park, Hyunjoo Lee, Jongheop Yi
      Abstract: Conversion of carbon dioxide for producing useful chemicals is an attractive method to reduce greenhouse gas emissions and to produce sustainable chemicals. However, the thermodynamic stability of CO₂ necessitates high levels of energy consumption for its conversion to chemicals. Here, we suggest a new catalytic system with an alternative heating system allowing for minimal energy consumption during CO₂ conversion. In this system, electrical energy is transferred as heat energy to the metal supported on carbon catalyst. Fast ramping rates allow for high operating temperatures (Tapp=250 °C) to be reached within 5 minutes, leading to an 80-fold lowering of energy consumption in methane reforming using CO₂ (DRM). In addition, the consumed energy normalized by time during DRM reaction in current-assisted catalysis is 6-fold lower (11.0 kJ·min-1) than conventional heating systems (68.4 kJ·min-1).
      PubDate: 2017-08-21T22:06:50.122792-05:
      DOI: 10.1002/cssc.201701283
  • Angelica Lactones: from Biomass-Derived Platform Chemicals to Value-Added
    • Authors: Arlene Correa; Carolina G. S. Lima, Júlia Monteiro, Thiago Melo Lima, Marcio Webber Paixão
      Abstract: The upgrading of biomass-derived compounds has arisen in recent years as a very promising research field in both academia and industry. In this sense, a lot of new processes and products have been developed, often involving levulinic acid as a starting material or intermediate. In the last few years, though, other scaffolds have been receiving growing attention, in special, angelica lactones. Considering these facts and the emergent applications of said molecules, in this review we will discuss their preparation and applications - the use of these frameworks as starting materials in organic synthesis to produce potential bioactive compounds will be covered, as well as their arising use as the foundation to highly regarded compounds such as liquid alkanes with prospective use as fuels and polymers.
      PubDate: 2017-08-21T10:00:39.20312-05:0
      DOI: 10.1002/cssc.201701469
  • Wacker Oxidation of Terminal Alkenes Over ZrO2-Supported Pd Nanoparticles
           Under Acid- and Cocatalyst-Free Conditions
    • Authors: Zhenzhong Zhang; Yuhya Kumamoto, Taishin Hashiguchi, Tetsuya Mamba, Haruno Murayama, Eiji Yamamoto, Tamao Ishida, Tetsuo Honma, Makoto Tokunaga
      Abstract: Highly efficient Wacker oxidation of aromatic or aliphatic terminal alkenes into methyl ketones and benzofurans is developed by using reusable Pd0 nanoparticles (NPs) supported on ZrO2 under acid- and cocatalyst-free conditions. Molecular oxygen or air can be utilized as the terminal oxidant, which results in the formation of H2O as the only theoretical byproduct. The activation of the Pd NPs by O2 plays an important role in promoting this reaction. Interestingly, PdO supported on ZrO2 showed no activity. Additionally, the Pd particle size significantly affects the catalytic activity, with an apparent optimal diameter of 4–12 nm. In addition to the heterogeneous catalyst forms, the Pd NPs can be generated from a Pd0 complex during the reaction, and these particles are even recyclable.Terminal alkenes take a Wacker! ZrO2-supported Pd0 NPs with a diameter of 4–12 nm exhibited high catalytic activity for Wacker oxidation and Wacker-type cyclization of terminal alkenes into methyl ketones and benzofurans. The reactions are performed under acid- and cocatalyst-free conditions, and O2 is employed as the sole oxidant.
      PubDate: 2017-08-21T03:07:03.479665-05:
      DOI: 10.1002/cssc.201701016
  • Interfacial heterojunction engineering of ZnIn₂S₄/MoSe₂ hierarchical
           nanoarchitectures for highly efficient noble-metal-free photocatalytic
           hydrogen evolution under visible light
    • Authors: Deqian Zeng; Lang Xiao, Wee-Jun Ong, Pengyuan Wu, Hongfei Zheng, Yuanzhi Chen, Dong-Liang Peng
      Abstract: Exploiting a highly efficient visible-light-driven photocatalyst is an urgent necessity for photocatalytic hydrogen (H₂) generation from water splitting. Herein, flower-like ZnIn₂S₄ hierarchical architectures assembled by ultrathin nanosheets were synthesized by a facile one-pot polyol approach, and subsequently, the colloidally developed two-dimensional (2D) network-like MoSe₂ was successfully hybridized with ZnIn₂S₄ via a facile hybridization approach by taking advantage of their analogues intrinsic layered morphologies. The ZnIn₂S₄/MoSe₂ heterostructures show enhanced noble-metal-free photocatalytic H₂ evolution compared to pure ZnIn₂S₄. It is noteworthy that the optimum nanocomposite of ZnIn₂S₄/2%MoSe₂ photocatalyst displays a dramatically high H₂ generation rate of 2228 μmol g¯¹ h¯¹ and an apparent quantum yield (AQY) of 21.39% at 420 nm. This study presents an unprecedented ZnIn₂S₄/MoSe₂ metal-sulfide/metal-selenide hybrid system for remarkable H₂ evolution. Importantly, the present efficient hybridization strategy uncovers a huge potential in the construction of hierarchical nanoarchitectures for a multitude of energy storage and solar energy conversion applications.
      PubDate: 2017-08-18T07:00:33.267296-05:
      DOI: 10.1002/cssc.201701345
  • Synthesis of renewable lubricant alkanes from biomass-derived platform
    • Authors: Mengyuan Gu; Qineng Xia, Xiaohui Liu, Yong Guo, Yanqin Wang
      Abstract: Catalytic synthesis of liquid alkanes from renewable biomass has received tremendous attention in recent years. However, highly branched lubricant alkanes are not yet synthetically exploited from biomass and are currently produced by hydrocracking and hydroisomerization of long-chain n-paraffins. Here we describe a selective catalytic synthetic route for the production of highly branched C23 alkanes for lubricant base oil component from biomass-derived furfural and acetone, through a tandem four-step process, namely aldol condensation of furfural with acetone to produce a C13 double adduct, then selective hydrogenation to a C13 ketone, followed by a second condensation of the C13 ketone with furfural to generate a C23 aldol adduct and finally to highly branched C23 alkanes by hydrodeoxygenation. The overall yield of C23 alkanes reaches in 50.6% (97.9%×72.8%×83.8%×84.8%) from furfural. This work opens a general strategy for the synthesis of high-quality lubricant alkanes from renewable biomass.
      PubDate: 2017-08-18T05:00:23.410735-05:
      DOI: 10.1002/cssc.201701200
  • Nanoparticles embedded in amphiphilic membranes for CO2 separation and
    • Authors: Wai Fen YONG; Yan Xun Ho, Tai-Shung Chung
      Abstract: Polymers containing ethylene oxide groups have gained significant interest as the ethylene oxide groups have favorable interactions with polar molecules such as H2O, quadrupolar molecules such as CO2 and metal ions. However, the main challenges of poly(ethylene oxide) (PEO) membranes are their weak mechanical properties and high crystallinity nature. The amphiphilic copolymer made from poly(ethylene oxide) terephthalate and poly(butylene terephthalate) (PEOT/PBT) comprising both hydrophilic and hydrophobic segments. The hydrophilic PEOT segment is thermosensitive that facilities gas transports while the hydrophobic PBT segment is rigid that provides mechanical robustness. This work demonstrates a novel strategy to design amphiphilic mixed matrix membranes (MMMs) by incorporating zeolitic imidazolate framework, ZIF-71, into the PEOT/PBT copolymer. The resultant membrane shows an enhanced CO2 permeability with an ideal CO2/N2 selectivity surpassing the original PEOT/PBT and Robeson's Upper bound line. The nanoparticles embedded amphiphilic membranes exhibit characteristics of high transparency and mechanical robustness. Mechanically strong composite hollow fiber membranes consisting PEOT/PBT/ZIF-71 as the selective layer have also been prepared. The resultant hollow fibers possess an excellent CO2 permeance of 131 GPU, CO2/N2 selectivity of 52.6, H2O permeance of 9,300 GPU and H2O/N2 selectivity of 3,700, showing great potential for industrial CO2 capture and dehumidification.
      PubDate: 2017-08-17T11:25:24.58133-05:0
      DOI: 10.1002/cssc.201701405
  • Catalytic Hydrodeoxygenation of High Carbon Furylmethanes to Renewable
           Jet-fuel Ranged Alkanes over a Rhenium-Modified Iridium Catalyst
    • Authors: Sibao Liu; Saikat Dutta, Weiqing Zheng, Nicholas S. Gould, Ziwei Cheng, Bingjun Xu, Basudeb Saha, Dionisios G. Vlachos
      Abstract: Invited for this month′s cover is the group of Basudeb Saha and Dionisios G. Vlachos at the Catalysis Center for Energy Innovation (CCEI), University of Delaware. The image shows the use of renewable aviation fuels produced from C−C coupled biomass platforms. The Full Paper itself is available at 10.1002/cssc.201700863.“Production of renewable materials is one of the most important topics in biorefineries…” This and more about the story behind the research that inspired the Cover image is presented in the Cover Profile. Read the full text of the corresponding research at 10.1002/cssc.201700863. View the Front Cover here: 10.1002/cssc.201701481.
      PubDate: 2017-08-16T06:45:42.522374-05:
      DOI: 10.1002/cssc.201701493
  • Catalytic Hydrodeoxygenation of High Carbon Furylmethanes to Renewable
           Jet-fuel Ranged Alkanes over a Rhenium-Modified Iridium Catalyst
    • Authors: Sibao Liu; Saikat Dutta, Weiqing Zheng, Nicholas S. Gould, Ziwei Cheng, Bingjun Xu, Basudeb Saha, Dionisios G. Vlachos
      Abstract: The Cover picture shows the use of renewable aviation fuels produced from C−C coupling and hydrodeoxygenation of lignocellulosic biomass-derived platform molecules. Production of these molecules occurs through an energy efficient process using a bifunctional Ir−ReOx/SiO2 catalyst and yields up to 99% branched chain alkanes at low temperature. The high efficiency and high products selectivity eliminate the need for complex separations and may render bio-based aviation fuels to become cost-competitive and sustainable. More details can be found in the Full Paper by Liu et al. (
      DOI : 10.1002/cssc.201700863).
      PubDate: 2017-08-16T03:30:27.299955-05:
  • Isohexide Dinitriles: A Versatile Family of Renewable Platform Chemicals
    • Authors: Jing Wu; Shanmugam Thiyagarajan, Célia Fonseca Guerra, Pieter Eduard, Martin Lutz, Bart A. J. Noordover, Cor E. Koning, Daan S. van Es
      Abstract: The Back Cover picture shows the base-induced epimerization of isohexide dinitrile compounds, which conveniently gives access to a family of isomeric isohexides building blocks extended by one carbon atom at the 2- or 5-position. More details can be found in the Full Paper by Wu et al. (
      DOI : 10.1002/cssc.201700617).
      PubDate: 2017-08-15T01:45:19.61131-05:0
  • Continuous production of bio-renewable, polymer-grade lactone monomers
           through Sn-β catalysed Baeyer-Villiger oxidation with H2O2
    • Authors: Keiko Yakabi; Thibault Mathieux, Kirstie Milne, Eva M Lopez-Vidal, Antoine Buchard, Ceri Hammond
      Abstract: The Baeyer-Villiger oxidation is a key transformation for sustainable chemical synthesis, especially when H2O2 and solid materials are employed as oxidant and catalyst, respectively. We demonstrate that 4-substituted cycloketones, readily available from renewables, present excellent platforms for Baeyer-Villiger upgrading. Such substrates exhibit substantially higher levels of activity, and produce lactones at higher levels of lactone selectivity at all values of substrate conversion, relative to non-substituted cyclohexanone. For 4-isopropyl cyclohexanone, readily available from β-pinene, continuous upgrading was also evaluated in a plug flow reactor. Excellent selectivity (< 90 % at 65 % conversion), stability and productivity were observed over 56 h, with over 1000 turnovers (mol. product / mol. Sn) being achieved with no loss of activity. A maximum space-time yield almost twice that obtained for non-substituted cyclohexanone was also obtained for this substrate (1173 vs. 607 g (product) kg-1 (cat) cm-3 (reactor) h-1). The lactone produced is also shown to be of suitable quality for ring opening polymerisation. In addition to demonstrating the viability of the Sn-β/H2O2 system to produce renewable lactone monomers suitable for polymer applications, the substituted alkyl cyclohexanones studied in this work also allowed us to probe the steric, electronic and thermodynamic elements of this transformation in greater detail than previously achieved.
      PubDate: 2017-08-13T21:25:39.988384-05:
      DOI: 10.1002/cssc.201701298
  • Synthetic Manipulation of Hybrid Perovskite Systems in Search of Novel and
           Enhanced Functionalities
    • Authors: Rounak Naphade; Satyawan Nagane, Umesh Bansode, Mukta Tathavadekar, Aditya Sadhanala, Satishchandra B. Ogale
      Abstract: Over the past few years the organic/Inorganic hybrid perovskite systems have emerged as a promising class of materials for photo-voltaic and electroluminescent thin film device applications, in view of their unique set of tunable optoelectronic properties. Importantly, these materials can be easily solution-processed at low temperatures and as such are amenable to facile molecular engineering. Thus, a variety of low dimensional forms and quantum structures of these materials can be obtained through strategic synthetic manipulations via small molecule incorporation or molecular ion doping. In this mini review, we specifically focus on these approaches and outline the possibilities of utilizing these for enhanced functionalities and newer application domains.
      PubDate: 2017-08-13T21:25:26.044652-05:
      DOI: 10.1002/cssc.201701093
  • Self-Co-Catalyzed Fluorine-Doped Hematite Nanocrystal for Efficient Water
    • Authors: Yi Xie; Junfeng Xie, Weiwei Liu, Jianping Xin, Fengcai Lei, Li Gao, Haichao Qu, Xiaodong Zhang
      Abstract: Herein, enhanced light absorption and oxygen-evolving activity were simultaneously achieved by doping fluorine anions into hematite nanocrystals. With the merits of anion doping, the band structure of hematite can be effectively regulated, leading to the generation of defect level between the bandgap and remarkably increased visible light absorption. In addition, the activity for electrocatalytic oxygen evolution reaction (OER) of the hematite nanocrystals exhibits obvious enhancement after fluorine doping, making the doped hematite play as an effective self-co-catalyst for photoelectrochemical water splitting. The optimization strategy proposed in this work by simultaneously tuning the intrinsic OER activity and light absorption may shed light on the future design of photocatalysts for energy-related applications.
      PubDate: 2017-08-12T02:25:29.241701-05:
      DOI: 10.1002/cssc.201701074
  • Electrochemical Reduction of Carbon Dioxide in a Monoethanolamine Capture
    • Authors: Jie Zhang; Lu Chen, Fengwang Li, Ying Zhang, Cameron Bentley, Mike Horne, Alan Bond
      Abstract: Electrocatalytic reduction of CO2 present in a 30% (w/w) monoethanolamine (MEA) aqueous solution has been undertaken at In, Sn, Bi, Pb, Pd, Ag, Cu and Zn metal electrodes. Upon dissolution of CO2, the non-conducting MEA solution is transformed into a conducting one, as needed for electrochemical reduction of CO2. Both an increase in the electrode surface porosity and addition of surfactant cetyltrimethylammonium bromide (CTAB) suppress the competing hydrogen evolution reaction with the latter having a significantly stronger impact. The combination of a porous metal electrode and 0.1% (w/w) of CTAB allows molecular CO2 to be reduced to CO and formate ([HCOO]-) with the product distribution being highly dependent on the identity of the metal electrode used. At a potential of -0.8 V vs. RHE, and use of coralline-like structured indium electrode, faradaic efficiencies for generation of CO and [HCOO]- are 22.8% and 54.5%, respectively compared to efficiencies of 2.9% and 60.8% with a porous lead electrode and 38.2% and 2.4% with a porous silver electrode. Extensive data for the other 5 electrodes are also provided. In addition to identifying optimal conditions for CO2 reduction, mechanistic details for reaction pathways are proposed in this proof of concept electrochemical study in a CO2 capture medium. Conditions and features needed to achieve industrially and commercially viable CO2 reduction in an amine based capture medium are considered.
      PubDate: 2017-08-10T21:25:32.953267-05:
      DOI: 10.1002/cssc.201701075
  • Two-Dimensional Materials as Prospective Scaffolds for Mixed-Matrix
           Membrane-Based CO2 Separation
    • Authors: Xiang Zhu; Chengcheng Tian, Chi-Linh Do-Thanh, Sheng Dai
      Abstract: Membrane-based CO2 separation technology plays a significant role in environmental remediation and clean energy. Two-dimensional (2D) materials with atomically precise structures have emerged as prospective scaffolds to develop mixed-matrix membranes (MMMs) for gas separation. Summarized in this perspective review are the latest breakthrough studies in the synthesis of 2D-material-based MMMs to separate CO2 from gas mixtures. 2D materials including graphene oxide (GO), metal–organic framework (MOF)-derived nanosheets, covalent organic frameworks (COFs), and transition metal dichalcogenides (TMDs), as fascinating building blocks, have been comprehensively summarized, together with a focus on synthetic processes and gas separation properties. Challenges and the latest advances in the manufacture of novel synthetic 2D materials are briefly discussed to foresee emerging opportunities for the development of new generations of 2D-material-based MMMs.Mixed business: Summarized in this Review are the latest breakthrough studies in the synthesis of 2D-material-based mixed-matrix membrane (MMMs) to separate CO2 from gas mixtures. 2D materials including graphene oxide (GO), metal–organic framework (MOF)-derived nanosheets, covalent organic frameworks (COFs), and transition metal dichalcogenides (TMDs), as fascinating building blocks, are discussed, with a focus on synthetic processes and gas separation properties.
      PubDate: 2017-08-10T10:43:25.162515-05:
      DOI: 10.1002/cssc.201700801
  • Low-Recombination Thieno[3,4-b]thiophene-based Photosensitizers for DSCs
           with Panchromatic IPCE Responses
    • Authors: Phillip Brogdon; Hammad Cheema, Jared Heath Delcamp
      Abstract: We report four NIR photosensitizers employing a low-recombination donor and a thieno[3,4-b]thiophene (3,4-TT) π-bridge for use in dye-sensitized solar cells. The inclusion of electron rich π-spacers red-shifts the dye absorbance with solution absorption onsets reaching 700 nm. Dyes were found to have suitable energy levels for rapid electron transfers via cyclic voltammetry and UV-Vis-NIR absorption spectroscopy. Computationally optimized ground-state geometries show an increased torsional angle between π-spacer and π-bridge brought about by an added alkyl chain resulting in a widened optical band gap and increased oxidation potentials due to a weakening of the electron accepting ability of 3,4-TT for solution measurements. Interestingly in terms of device parameters, the alkylated π-spacer had a nearly identical incident photon-to-current conversion efficiency curve onset suggesting more similar dye geometries on the surface of TiO2. Elevated JSC values and comparable VOC values were observed in the alkylated π-spacer dye-based devices with power conversion efficiencies up to 6.8% observed with IPCE onsets exceeding 800 nm.
      PubDate: 2017-08-08T21:21:17.034053-05:
      DOI: 10.1002/cssc.201701259
  • New Insights into the Hydrothermal Stability of Triamine-Functionalized
           SBA-15 Silica for CO2 Adsorption
    • Authors: Masoud Jahandar Lashaki; Hessam Ziaei-Azad, Abdelhamid Sayari
      Abstract: The hydrothermal stability of triamine-grafted, large-pore SBA-15 CO2 adsorbents was studied using steam stripping. Following two 3-h cycles of steam regeneration, lower CO2 uptakes, lower CO2/N ratios, and slower adsorption kinetics were observed relative to fresh samples, particularly at the lowest adsorption temperature (25 oC). CO2 adsorption measurements for a selected sample exposed to 48 h of steam stripping depicted that after the initial loss during the first exposure to steam (3 to 6 h), the adsorptive properties stabilized. For higher adsorption temperatures (i.e., 50 and 75 oC), however, all adsorptive properties remained almost unchanged after steaming, indicating the significance of diffusional limitations. TGA and FT-IR spectroscopy results for grafted samples before and after steam stripping showed no amine leaching and no change in the chemical nature of the amine groups, respectively. However, N2 adsorption measurement at 77 K showed significant reductions in the BET surface area of the grafted samples following steaming. Based on the pore size distribution of calcined, grafted samples before and after steaming, it is proposed that exposure to steam restructured the grafted materials, causing mass transfer resistance. It is inferred that triamine-grafted, large-pore SBA-15 adsorbents are potential candidates for CO2 capture at relatively high temperatures (50 to 75 oC; e.g. flue gas) combined with steam regeneration.
      PubDate: 2017-08-08T10:15:28.531151-05:
      DOI: 10.1002/cssc.201701439
  • Highly efficient sulfonic/carboxylic dual-acid synergistic catalysis for
           esterification enabled by sulfur-rich graphene oxide (GO-S)
    • Authors: Honglei Zhang; Xiang Luo, Kaiqi Shi, Tao Wu, Feng He, Shoubin Zhou, George Chen, Chuang Peng
      Abstract: A new sulfonic/carboxylic dual-acid catalyst based on sulfur-rich graphene oxide (GO-S) was readily prepared and used as a highly efficient and reusable solid acid catalyst towards the esterification of oleic acid with methanol for biodiesel production. Higher yields of methyl oleate (98 %) and over 3 times higher turnover frequencies (TOF) were observed for the GO-S dual-acid catalyst, compared to liquid sulfuric acid or other carbon-based solid acid catalysts. The "acidity" of sulfonic acid groups was enhanced by the addition of carboxylic acid groups since the combination of the two acids enhances their inherent activity by associative interaction.
      PubDate: 2017-08-08T00:15:21.929959-05:
      DOI: 10.1002/cssc.201700950
  • Exploitation of catalytic promiscuity of hemoglobin for NAD(P)+ in situ
           regeneration in dehydrogenase-catalyzed oxidation of furanics
    • Authors: Hao-Yu Jia; Min-Hua Zong, Hui-Lei Yu, Ning Li
      Abstract: In this work, catalytic promiscuity of hemoglobin (Hb) was explored for regeneration of oxidized nicotinamide cofactors (NAD(P)+). With H2O2 as oxidant, Hb was able to efficiently oxidize NAD(P)H into NAD(P)+ in 30 min. The new NAD(P)+ regeneration system was coupled with horse liver alcohol dehydrogenase (HLADH) for the oxidation of bio-based furanics such as furfural and 5-hydroxymethylfurfural (HMF). The target acids (e.g., 2,5-furandicarboxylic acid, FDCA) were afforded with moderate to good yields. In addition, the enzymatic regeneration method was applied in L-glutamic DH-mediated oxidative deamination of L-glutamate and L-lactic DH-mediated oxidation of L-lactate, which furnished α-ketoglutarate and pyruvate, respectively, with the yields of 97% and 81%. The total turnover number (TTN) up to approximately 5000 for cofactor and the E factor of less than 110 were obtained in the bi-enzymatic cascade synthesis of α-ketoglutarate. Overall, a proof-of-concept based on catalytic promiscuity of Hb was provided for in situ regeneration of NAD(P)+ in DH-catalyzed oxidation reactions.
      PubDate: 2017-08-07T21:26:12.980599-05:
      DOI: 10.1002/cssc.201701288
  • Performance and ageing robustness of graphite/NMC pouch prototypes
           manufactured through eco-materials and processes
    • Authors: Nicholas Loeffler; Guk-Tae Kim, Stefano Passerini, Cesar Gutierrez, Iosu Cendoya, Iratxe de Meatza, Fabrizio Alessandrini, Giovanni Battista Appetecchi
      Abstract: Graphite/lithium nickel-manganese-cobalt oxide, stacked pouch cells with nominal capacity of 15-18 A h were designed, developed and manufactured for automotive applications in the frame of the European Project GREENLION. A natural, water-soluble material was used as the main electrode binder, thus allowing the employment of H2O as the only processing solvent. The electrode formulations were developed, optimized and up scaled for cell manufacturing. Prolonged cycling and ageing tests have revealed excellent capacity retention and robustness towards degradation phenomena. For instance, above 99% of the initial capacity is retained upon 500 full charge/discharge cycles, corresponding to a fading of 0.004% per cycle, and about 80% of the initial capacity is delivered after 8 months ageing at 45 °C. The stacked soft-packaged cells have shown very reproducible characteristics and performance, reflecting the goodness of design and manufacturing.
      PubDate: 2017-08-07T10:20:20.320455-05:
      DOI: 10.1002/cssc.201701087
  • Iron-Doped BaMnO3 for Hybrid Water Splitting and Syngas Generation
    • Authors: Vasudev Pralhad Haribal; Feng He, Amit Mishra, Fanxing Li
      Abstract: A rationalized strategy to optimize transition-metal-oxide-based redox catalysts for water splitting and syngas generation through a hybrid solar-redox process is proposed and validated. Monometallic transition metal oxides do not possess desirable properties for water splitting; however, density functional theory calculations indicate that the redox properties of perovskite-structured BaMnxFe1−xO3−δ can be varied by changing the B-site cation compositions. Specifically, BaMn0.5Fe0.5O3−δ is projected to be suitable for the hybrid solar-redox process. Experimental studies confirm such predictions, demonstrating 90 % steam-to-hydrogen conversion in water splitting and over 90 % syngas yield in the methane partial-oxidation step after repeated redox cycles. Compared to state-of-the-art solar-thermal water-splitting catalysts, the rationally designed redox catalyst reported is capable of splitting water at a significantly lower temperature and with ten-fold increase in steam-to-hydrogen conversion. Process simulations indicate the potential to operate the hybrid solar-redox process at a higher efficiency than state-of-the-art hydrogen and liquid-fuel production processes with 70 % lower CO2 emissions for hydrogen productionPerovskite power: BaMn0.5Fe0.5O3−δ demonstrates over 90 % water-splitting conversion and over 90 % syngas-yield using a hybrid solar-redox process. Computational modelling, fluidized-bed experiments, and in situ XRD analysis indicate that perovskite BaMn0.5Fe0.5O3−δ is ideal for the proposed redox reactions. Process simulations indicate a 70 % reduction in CO2 emissions for hydrogen production compared to the current state-of-the-art processes.
      PubDate: 2017-08-07T06:41:27.409496-05:
      DOI: 10.1002/cssc.201700699
  • Electrochemical Reduction of Protic Supercritical CO2 on Copper Electrodes
    • Authors: Olga Melchaeva; Patrick Voyame, Victor Costa Bassetto, Michael Prokein, Manfred Renner, Eckhard Weidner, Marcus Petermann, Alberto Battistel
      Abstract: The electrochemical reduction of carbon dioxide is usually studied in aqueous solutions under ambient conditions. However, the main disadvantages of this method are high hydrogen evolution and low faradaic efficiencies of carbon based products. Supercritical CO2 (scCO2) can be used as a solvent itself to suppresses hydrogen evolution and tune carbon based product yield, however, it received low attention. Therefore, the focus of this study was on the electrochemical reduction of supercritical CO2 (at 40 ˚C and 80 bar). The conductivity of scCO2 was increased through addition of supporting electrolyte and co-solvent (acetonitrile). Besides, the addition of protic solutions with different pH to supercritical CO2 was investigated. 1 M H2SO4, trifluoroethanol, H2O, KOH, and CsHCO3 solutions were used to determine the effect on current density, faradaic efficiency, and selectivity of scCO2 reduction. Reduction of supercritical CO2 to methanol and ethanol were reported for the first time. However, methane and ethylene were not observed. Additionally, corrosion of Cu was noticed.
      PubDate: 2017-08-07T04:15:23.298037-05:
      DOI: 10.1002/cssc.201701205
  • Fast and robust: novel highly active N,O zinc guanidine catalysts for the
           ring-opening polymerisation of lactide
    • Authors: Sonja Herres-Pawlis; Pascal Schäfer, Martin Fuchs, Andreas Ohligschläger, Ruth Rittinghaus, Paul McKeown, Enver Akin, Maximilian Schmidt, Alexander Hoffmann, Marcel Liauw, Matthew D. Jones
      Abstract: New zinc guanidine complexes with N,O donor functionalities have been prepared, characterized by X-Ray crystallography and examined for their catalytic activity in the solvent-free ring-opening polymerization (ROP) of technical-grade rac-lactide at 150 °C. All complexes showed a high activity. The fastest complex [ZnCl2(DMEGasme)] (C1) produced colorless poly(lactide) (PLA) after 90 min with a conversion of 52 % and high molar masses (Mw = 69100, PD = 1.4). The complexes have been tested with different monomer-to-initiator ratios to determine the rate constant kp. Furthermore, a polymerization with the most active complex C1 has been monitored by in situ Raman spectroscopy. Overall, conversion up to 90 % can be obtained. To clarify the mechanism end-group analysis has been performed. All four complexes combine robustness against impurities in the lactide with high polymerization rates, and they represent the fastest robust lactide ROP catalysts to date, opening new avenues to a sustainable ROP catalyst family for industrial use.
      PubDate: 2017-08-05T00:06:35.032423-05:
      DOI: 10.1002/cssc.201701237
  • Self-Assembled Dendritic Pt Nanostructure with High-Index Facets as Highly
           Active and Durable Electrocatalyst for Oxygen Reduction
    • Authors: Youngjin Jang; Kwang-Hyun Choi, Dong Young Chung, Ji Eun Lee, Namgee Jung, Yung-Eun Sung
      Abstract: The Inside Cover picture shows a graphical representation of the oxygen reduction reaction on self-assembled dendritic Pt nanoparticles in proton-exchange membrane fuel cells. The Pt nanodendrite catalyst exhibits high catalytic activity and durability owing to the formation of well-organized dendritic structures with plenty of reactive interfaces and the coexistence of low- and high-index facets on the particles. More details can be found in the Full Paper by Jang et al. (
      DOI : 10.1002/cssc.201700852).
      PubDate: 2017-08-04T06:30:21.017879-05:
  • Catalyst particle density controls hydrocarbon product selectivity in CO2
           electroreduction on CuOx
    • Authors: Xingli Wang; Ana Sofia Varela, Arno Bergmann, Stefanie Kuehl, Peter Strasser
      Abstract: A key challenge of the carbon dioxide electroreduction (CO2RR) on Cu-based nanoparticles is its low faradic selectivity towards higher-value products such as ethylene. Here, we demonstrate a facile method for tuning the hydrocarbon selectivities on CuOx nanoparticle ensembles by varying the nanoparticle areal density. The sensitive dependence of the experimental ethylene selectivity on catalyst particle areal density is attributed to a diffusional interparticle coupling which controls the de- and re-absorption of CO and thus the effective coverage of COad intermediates. Thus, higher areal density constitutes dynamically favoured conditions for CO re-adsorption and *CO dimerization leading to ethylene formation independent of pH and applied overpotential.
      PubDate: 2017-08-04T03:00:39.194668-05:
      DOI: 10.1002/cssc.201701179
  • Evaluating Dihydroazulene/Vinylheptafulvene Photoswitches for Solar Energy
           Storage Applications
    • Authors: Zhihang Wang; Jonas Udmark, Karl Börjesson, Rita Rodrigues, Anna Roffey, Maria Abrahamsson, Mogens Brøndsted Nielsen, Kasper Moth-Poulsen
      Abstract: The Cover picture shows an implementation of molecular solar thermal energy storage (MOST) technology on a large scale. It illustrates how the yellow-colored dihydroazulene (DHA) is converted into red-colored vinylheptafulvene (VHF) upon irradiation. The robust nature of this system was demonstrated through multiple energy storage-and-release cycles. As a potential candidate for the MOST concept, the photoswitch was evaluated both under simulated sunlight conditions as well as under natural outdoor conditions, demonstrating a possible avenue for future lab-to-site transfer. More details can be found in the Full Paper by Wang et al. (
      DOI : 10.1002/cssc.201700679).
      PubDate: 2017-08-04T01:21:41.473316-05:
  • Graphene-Supported Pyrene-Modified Cobalt Corrole with a
           Triphenylphosphine Axial Ligand for Enhanced Hydrogen Evolution in pH 0-14
           Aqueous Solutions
    • Authors: Xialiang Li; Haitao Lei, Xiaojun Guo, Xueli Zhao, Shuping Ding, Xueqing Gao, Wei Zhang, Rui Cao
      Abstract: A cobalt complex of 5,15-bis-(pentafluorophenyl)-10-(4)-(1-pyrenyl)phenyl corrole containing a triphenylphosphine axial ligand (1-PPh3) was synthesized and examined as an electrocatalyst for the hydrogen evolution reaction (HER). When supported on graphene (G), the resulted 1-PPh3/G material can catalyze HER in aqueous solutions over a wide pH range of 0-14 with high efficiency and durability. The significantly enhanced activity of 1-PPh3/G, compared with those of its analogues 1-py/G (the Co-bound axial ligand is pyridine instead of triphenylphosphine) and 2-py/G (Co complex of 5,10,15-tris(pentafluorophenyl)corrole), highlights the effects of pyrenyl substituent and triphenylphosphine axial ligand on HER. On one hand, the pyrenyl moiety can increase the π-π interactions between 1 and graphene and thus lead to a fast electron transfer from the electrode to 1. On the other hand, the triphenylphosphine axial ligand can increase the electron density (basicity) of Co and thus make the metal center more reactive to protons at the trans position through a so-called "push effect". This work is thus significant to present an example showing the trans effect of the axial ligand on HER, which has rarely been investigated. The combination of various ligand design strategies in one molecule has been realized in 1-PPh3 to achieve high catalytic HER performance. These factors are valuable to be used in other molecular catalyst systems.
      PubDate: 2017-08-03T09:06:21.083174-05:
      DOI: 10.1002/cssc.201701196
  • Evaluating Dihydroazulene/Vinylheptafulvene Photoswitches for Solar Energy
           Storage Applications
    • Authors: Zhihang Wang; Jonas Udmark, Karl Börjesson, Rita Rodrigues, Anna Roffey, Maria Abrahamsson, Mogens Brøndsted Nielsen, Kasper Moth-Poulsen
      Abstract: Invited for this month′s cover are the groups of Kasper Moth-Poulsen at Chalmers University of Technology and Mogens Brøndsted Nielsen at University of Copenhagen. The cover image shows a conceptual graphic of molecular solar thermal energy storage system (MOST) for outdoor facilities. The Full Paper itself is available at 10.1002/cssc.201700679.“We demonstrate how this couple shows promise as a MOST candidate in flow systems…” This and more about the story behind the research that inspired the Cover image is presented in the Cover Profile. Read the full text of the corresponding research at 10.1002/cssc.201700679. View the Front Cover here: 10.1002/cssc.201701336.
      PubDate: 2017-08-03T07:05:21.256315-05:
      DOI: 10.1002/cssc.201701337
  • Chemo-enzymatic synthesis of a novel borneol-based polyester
    • Authors: Steffen Roth; Irina Funk, Michael Hofer, Volker Sieber
      Abstract: Terpenes are a class of natural compounds that have recently moved into the focus as bio-based resource for chemicals productions due to their abundance, their mostly cyclic structure and the presence of olefin or single hydroxyl groups. In order to apply this raw material in new industrial fields, a second hydroxyl group is inserted into borneol by cytochrome P450cam (CYP101) enzymes in a whole cell catalytic biotransformation with Pseudomonas putida KT2440. Next, a semi-continuous batch system was developed to produce 5-exo-hydroxyborneol with a final concentration of 0.54 g L-1. The bifunctional terpene was then used for the synthesis of an all bio-based polyesters by a solvent free polycondensation reaction. The resulting polymer showed a glass transition temperature around 70 °C and a molecular weight in the range of 2,000 - 4,000 g mol-1 (Mw). These results show that whole cell catalytic biotransformation of terpenes could lead to bio-based, higher-functionalized monomers, which might be basic raw materials for different fields of application, such as biopolymers.
      PubDate: 2017-08-03T03:00:43.382876-05:
      DOI: 10.1002/cssc.201701146
  • Chemical Pulping Advantages of Zip-lignin Hybrid Poplar
    • Authors: Shengfei Zhou; Troy Runge, Steven Karlen, John Ralph, Eliana Gonzales-Vigil, Shawn Mansfield
      Abstract: Hybrid poplar genetically engineered to possess chemically labile ester linkages in its lignin backbone (Zip-lignin™ hybrid poplar) was examined to determine if the strategic lignin modifications would enhance chemical pulping efficiencies. Kraft pulping of Zip-lignin and wild-type hybrid poplar was carried out in lab-scale reactors under varying severity conditions of time, temperature and chemical charge. The resulting pulps were analyzed for yield, residual lignin content, and cellulose DP (degree of polymerization), as well as changes in carbohydrates and lignin structure. Statistical models of pulping were created, and the pulp bleaching and physical properties evaluated. Compared to wild-type, the Zip-lignin hybrid poplar cooked under identical conditions showed extended delignification, confirming the Zip-lignin effect. Additionally, yield and carbohydrate content of the ensuing pulps were slightly elevated, as was the cellulose DP for Zip-lignin poplar pulp, although differences in residual lignin between Zip-lignin and wild-type poplar were not detected. Statistical prediction models facilitated comparisons between pulping conditions that resulted in identical delignification, with the Zip-lignin poplar needing milder cooking conditions and resulting in higher pulp yield (up to 1.41% gain). Bleaching and physical properties were equivalent between the samples with slight chemical savings realized in the Zip-lignin samples due to the enhanced delignification.
      PubDate: 2017-08-02T11:00:21.177803-05:
      DOI: 10.1002/cssc.201701317
  • CsPb2Br5 Single Crystals: Synthesis and Characterization
    • Authors: Ibrahim Dursun; Michele De Bastiani, Bekir Turedi, Badriah Alamer, Aleksander Shkurenko, Jun Yin, Issam Gereige, Ahmed Alsaggaf, Omar F. Mohammed, Mohamed Eddaoudi, Osman M. Bakr
      Abstract: CsPb2Br5 is a ternary halogen-plumbate material with close characteristics to well-reported halide perovskites. Due to its unconventional two-dimensional structure, CsPb2Br5 is being looked at broadly for potential applications in optoelectronics. CsPb2Br5 investigations are currently limited to nanostructures and powder forms of the material, which present unclear and conflicting optical properties. In this study, we present the synthesis and characterization of CsPb2Br5 bulk single crystals, which enabled us to finally clarify the material's optical features. Our CsPb2Br5 crystal has a two-dimensional structure with Pb2Br5- layers spaced by Cs+ cations, and exhibits a ~3.1 eV indirect bandgap with no emission in the visible spectrum.
      PubDate: 2017-08-01T21:00:37.064473-05:
      DOI: 10.1002/cssc.201701131
  • Voronoi Tessellated Graphite Produced by Low Temperature Catalytic
           Graphitization of Renewable Hard Carbon
    • Authors: Leyi Zhao; Xiuyun Zhao, Luke Burke, Craig Bennett, Richard Dunlap, Mark Obrovac
      Abstract: A highly crystalline graphite powder was prepared from the low temperature (800-1000 °C) graphitization of renewable hard carbon precursors using a magnesium catalyst. The resulting graphite particles are composed of Voronoi tessellated regions comprising irregular sheets, each Voronoi tessellated region having a small "seed" particle located near their centroid on the surface. This suggests nucleated outward growth of graphitic carbon, which has not been previously observed. Each seed particle consists of a spheroidal graphite shell on the inside of which hexagonal graphite platelets are perpendicularly affixed. This results in a unique high surface area graphite with a high degree of graphitization that is made with renewable feedstocks at temperatures far below that conventionally used for artificial graphites.
      PubDate: 2017-08-01T14:00:38.84326-05:0
      DOI: 10.1002/cssc.201701211
  • Mapping the Free Energy of Lithium Solvation in the Protic Ionic Liquid
           Ethylammonuim Nitrate: A Metadynamics Study
    • Authors: Ali Kachmar; Marcelo Carignano, Teodoro Laino, Marcella Iannuzzi, Jürg Hutter
      Abstract: The Back Cover picture shows the free energy landscape for Li+ solvation in ethyleammonuim nitrate (EAN). Using first-principle simulations aided by a metadynamics approach, the solvation and transport of lithium in EAN was investigated. We identified different lithium solvation scenarios that were explored by the metadynamics and quantified their free energy barriers. The lowest free-energy barrier appears to be consistent with what has been observed experimentally. More details can be found in the Full Paper by Kachmar et al. (
      DOI : 10.1002/cssc.201700510).
      PubDate: 2017-08-01T09:25:20.504444-05:
  • Hindered Amine Light Stabilizers increase stability of Methylammonium Lead
           Iodide Perovskite against Light and Oxygen
    • Authors: Juan L. Delgado; Nevena Marinova, marius Franckevičius, Ieva Matulaitienė, Andrius Devižis, Gediminas Niaura, Vidmantas Gulbinas
      Abstract: Methylammonium lead iodide perovskite (MAPI) is a promising material for highly-efficient photovoltaic devices. However, it suffers from photooxidation, which imposes strict requirements for its protection from oxygen during processing and operation. Herein we report the unprecedented stabilization effect of hindered amine light stabilizer (HALS) on methylammonium iodide (MAI) and MAPI against photooxidation. We found that HALS prevents the degradation of MAI by inhibiting the oxidation of iodide to iodine. Chemical modification of HALS allows us to incorporate it in MAPI films which extends the resistivity of MAPI against photodegradation at ambient air from a couple of hours to several days, while causing no significant changes in key properties, such as optical absorption and charge transport. These results represent an important advance in the fight against MAPI decomposition and demonstrate for the first time that antioxidants improve the stability of MAPI.
      PubDate: 2017-08-01T06:22:03.273079-05:
      DOI: 10.1002/cssc.201700707
  • Efficient and Chemoselective Semihydrogenation of Alkynes Catalyzed by Pd
           Nanoparticles Immobilized on Heteroatom-Doped Hierarchical Porous Carbon
           Derived from Bamboo Shoots
    • Authors: yong yang; Guijie Ji, Yanan Duan, Shaochun Zhang, Benhua Fei, Xiufang Chen
      Abstract: Highly dispersed palladium nanoparticles (Pd NPs) immobilized by a heteroatom-doped hierarchical porous carbon support (N,O-Carbon) with large specific surface areas are synthesized by a wet chemical reduction method, wherein the N,O-Carbon derived from naturally available and reusable bamboo shoots is fabricated by a tandem hydrothermal-carbonization process without assistance of any templates or chemical activation reagents or exogenous N and O source in a simple and eco-friendly manner. The prepared Pd@N,O-Carbon catalyst shows extremely high activity and excellent chemoselectivity for semihydrogeantion of a broad range of alkynes to versatile and valuable alkenes under ambient conditions. The catalyst can be readily recovered for successive reuse with negligible loss in activity and selectivity and is also applicable for gram-scale transformation, which highlights its highly practical potential.
      PubDate: 2017-08-01T05:20:36.896653-05:
      DOI: 10.1002/cssc.201701127
  • Strongly Coupled Molybdenum Carbide@Carbon Sheets as a Bifunctional
           Electrocatalyst for Overall Water Splitting
    • Authors: Hao Wang; Yingjie Cao, Cheng Sun, Guifu Zou, Jianwen Huang, Xiaoxiao Kuai, Jianqing Zhao, Lijun Gao
      Abstract: High-performance and affordable electrocatalysts from earth-abundant elements are desirably pursued for water splitting involving hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In this work, a bifunctional electrocatalyst of highly crystalline Mo2C nanoparticles supported on carbon sheets (Mo2C@CS) is designed towards overall water splitting. Owing to the highly active catalytic nature of Mo2C nanoparticles, the high surface area of carbon sheets and the efficient charge transfer in the strongly coupled composite, the designed catalysts show excellent bifunctional behavior with an onset potential of -60 mV for HER and an overpotential of 320 mV to achieve a current density of 10 mA cm-2 for OER in 1 M KOH while maintaining robust stability. Meanwhile, the cell using the catalyst only requires a low cell voltage of 1.73 V to achieve a current density of 10 mA cm-2 and maintains the activity for more than 100 hours when employing the Mo2C@CS catalyst as both anode and cathode electrodes in a water electrolyzer. Such high performance makes Mo2C@CS a promising electrocatalyst for practical hydrogen production from water splitting.
      PubDate: 2017-07-30T21:20:57.988675-05:
      DOI: 10.1002/cssc.201701276
  • A Complete Selectivity for the Direct Synthesis of Hydrogen Peroxide over
           Palladium-Tellurium Catalysts at Ambient Pressure
    • Authors: Pengfei Tian; Xingyan Xu, Can Ao, Doudou Ding, Wei Li, Rui Si, Weifeng Tu, Jing Xu, Yi-Fan Han
      Abstract: Highly selective hydrogen peroxide (H2O2) synthesis directly from H2 and O2 is a strongly desired reaction for green process. We report a highly efficient palladium-tellurium (Pd-Te/TiO2) catalyst with a selectivity of ~100% toward H2O2 under mild conditions (283 K, 0.1 MPa and a semi-batch continuous flow reactor). The size of Pd particles was remarkably reduced from 2.1 nm to 1.4 nm with the addition of Te; meanwhile, the surface Pd atoms modified by Te could significantly weaken the dissociative activation of O2, leading to the non-dissociative hydrogenation of O2. Density functional theory (DFT) calculations illuminated the critical role of Te in the selective hydrogenation of O2 that the active sites composed of Pd and Te could significantly restrain the side reactions. This work has made a significant progress on the development of high-selectivity catalysts for the direct synthesis of H2O2 at ambient pressure.
      PubDate: 2017-07-28T01:56:07.436752-05:
      DOI: 10.1002/cssc.201701238
  • Corrigendum: Towards an Understanding of Li2O2 Evolution in Li–O2
           Batteries: An In Operando Synchrotron X-ray Diffraction Study
    • Authors: Chenjuan Liu; William R. Brant, Reza Younesi, Yanyan Dong, Kristina Edström, Torbjörn Gustafsson, Jiefang Zhu
      PubDate: 2017-07-28T01:35:20.14531-05:0
      DOI: 10.1002/cssc.201701241
  • Broadband Emitting 2D-Hybrid Organic Inorganic Perovskite Based on
           Cyclohexane-bis(methylamonium) Cation
    • Authors: Ishita neogi; Annalisa Bruno, Damodaran Bahulayan, Teck Wee Goh, Biplab Ghosh, Rakesh Ganguly, Daniele Cortecchia, Tze Chien Sum, Cesare Soci, Nripan Mathews, Subodh Gautam Mhaisalkar
      Abstract: A novel broadband emitting 2D-hybrid organic inorganic perovskite (CyBMA)PbBr4 based on highly flexible cis-1,3-bis(methylaminohydrobromide)cyclohexane (CyBMABr) core has been designed, synthesized and investigated, highlighting the effects of stereoisomerism of the templating cation on the formation and properties of the resulting perovskite. The new 2D-material has high exciton binding energy of 340 meV and a broad emission spanning from 380-750 nm, incorporating a prominent excitonic band and a less intense broad peak at room temperature. Prominent changes in the photoluminescence spectrum were observed at lower temperatures, showing remarkable enhancement in the intensity of broad band at the cost of excitonic emission. Temperature dependent PL mapping indicate the effective role of only a narrow band of excitonic absorption in the generation of the active channel for emission. Based on the evidences obtained from the photo-physical investigations, we attributed the evolution of the broad B-band of (CyBMA)PbBr4 to excitonic self-trapped states
      PubDate: 2017-07-28T00:55:49.501421-05:
      DOI: 10.1002/cssc.201701227
  • Robust Cooperative Photooxidation of Sulfides without Sacrificial Reagent
           under Air Using A Dinuclear RuII-CuII Assembly
    • Authors: Duobin Chao; Mengying Zhao
      Abstract: A molecular chromophore-catalyst assembly containing a chromophore ruthenium(II) center (RuIIchro) and a catalytic copper(II) center (CuIIcat) has been prepared facilely. The assembly was employed for photocatalytic oxidation of sulfides without sacrificial reagent in the presence of dioxygen under blue light irradiation. Unprecedented turnover number (TON) up to 32000 was achieved. It was elucidated that an electron transferred from excited state of chromophore RuII*chro to CuIIcat along with generation of CuIcat that was further activated by O2. These results demonstrate a promising strategy for efficient cooperative photocatalytic reactions under air using chromophore-catalyst assembly.
      PubDate: 2017-07-26T09:25:31.146396-05:
      DOI: 10.1002/cssc.201700930
  • Design Rules for Oxygen Evolution Catalysis at Porous Iron Oxide
           Electrodes: Thousand-Fold Current Density Increase
    • Authors: Sandra Haschke; Dmitrii Pankin, Yuri Petrov, Sebastian Bochmann, Alina Manshina, Julien Bachmann
      Abstract: Nanotubular iron(III) oxide electrodes are optimized for catalytic proficiency in the water oxidation reaction at neutral pH. Nanostructured electrodes are prepared from anodic alumina templates coated with Fe2O3 by atomic layer deposition. Scanning helium ion microscopy, X-ray diffraction and Raman spectroscopy characterize the morphology and phase of samples submitted to various treatments. These methods document the contrasting effects of thermal annealing, on the one hand, and of electrochemical treatment, on the other hand. The electrochemical performance of the corresponding electrodes in dark conditions is quantified by steady-state electrolyses and electrochemical impedance spectroscopy. A rough and amorphous Fe2O3 with phosphate incorporation proves to be optimal in the water oxidation reaction. In combination with the ideal pore length L = 17 μm, the maximized catalytic turnover is reached with an effective current density J = 140 μA cm(-2) at 0.49 V applied overpotential η.
      PubDate: 2017-07-26T04:26:19.037639-05:
      DOI: 10.1002/cssc.201701068
  • Aquivion PFSA as an Efficient Pickering Interfacial Catalyst for the
           Hydrolysis of Triglycerides
    • Authors: Marc Pera-Titus; Hui Shi, Bing Hong, Flora Fan
      Abstract: Aquivion® Perfluorosulfonic Superacid catalyzed efficiently the solvent-free hydrolysis of glyceryl trilaurate at 100 oC and ambient pressure via the genesis of stable Pickering emulsions.
      PubDate: 2017-07-25T09:26:38.235951-05:
      DOI: 10.1002/cssc.201700663
  • Carbon dioxide capture by aqueous ionic liquid solutions
    • Authors: Jairton Dupont; Nathalia M. Simon, Marcileia Zanatta, Francisco P. dos Santos, Marta C. Corvo, Eurico J. Cabrita
      Abstract: Confined water in aqueous solutions of imidazolium-based ionic liquids (ILs) associated with acetate and imidazolate anions react reversibly with CO2 to yield bicarbonate. Three types of CO2 sorption in these "IL-aqueous solutions" were observed: physical, CO2-imidazolium adduct generation and bicarbonate formation (up to 1.9 mol of bicarbonate/mol of IL), resulting in a 10/1 mol/mol total absorption of CO2 relative to imidazolate anions in the presence of water 1/1000 (IL/water). These sorption values are higher than the classical alkanol amines or even alkaline aqueous solutions under similar experimental conditions.
      PubDate: 2017-07-25T09:26:07.257338-05:
      DOI: 10.1002/cssc.201701044
  • Towards extending solar cells life time : Addition of a fluorous cation to
           triple-cation based perovskite films
    • Authors: Manuel Salado; M Asunción Fernández, Juan P Holgado, Samrana Kazim, M. K. Nazeeruddin, P J Dyson, Shahzada Ahmad
      Abstract: Organo metal halide perovskites have emerged as highly promising replacements for thin film solar cells. However, their poor stability under ambient conditions remains problematic, hindering commercial exploitation. Here, we describe our investigation on the incorporation of a fluorous-functionalized imidazolium cation in a highly stable cesium based mixed perovskite material (Cs0.05(MA0.15FA0.85)0.95Pb(I0.85Br0.15)3 and how it influnce enhances stability. The resulting materials, which vary according to the content of the fluorous-functionalized imidazolium cation, display a prolonged tolerance to atmospheric humidity (>100 days) along with power conversion efficiencies exceeding 16%. This work provides a general route which can be implemented in variety of perovskites and highlights a promising way to increase perovskite solar cell stability.
      PubDate: 2017-07-25T04:20:28.148225-05:
      DOI: 10.1002/cssc.201700797
  • Pseudocapacitive desalination of brackish water and seawater via vanadium
           pentoxide decorated multi-walled carbon nanotubes
    • Authors: Juhan Lee; Pattarachai Srimuk, Katherine Aristizabal, Choonsoo Kim, Soumyadip Choudhury, Yoon-Chae Nah, Frank Mücklich, Volker Presser
      Abstract: We introduce membrane pseudocapacitive deionization (MPDI) of a hybrid cell consisting of one electrode of hydrated vanadium pentoxide (hV2O5) decorated on multi-walled carbon nanotubes electrode (MWCNT) and one electrode of activated carbon. This hybrid system enables sodium removal by pseudocapacitive intercalation to MWCNT-hV2O5 electrode and chloride removal by non-Faradaic electrosorption of the porous carbon electrode. MWCNT-hV2O5 electrode was synthesized by electrochemical deposition of hydrated vanadium pentoxide on the MWCNT paper. The stable electrochemical operating window for MWCNT-hV2O5 electrode is identified between -0.5 V and +0.4 V vs. Ag/Cl which provides a specific capacity of 44 mAh/g (corresponds with 244 F/g) in aqueous 1 M NaCl. The desalination performance of the MPDI system was investigated in aqueous 200 mM NaCl (brackish water) and 600 mM NaCl (sea water) solutions. With the aid of an anion and a cation exchange membrane, the MPDI hybrid cell was operated from -0.4 V to +0.8 V cell voltage without crossing the reduction and oxidation potential limit of both electrodes. For the 600 mM NaCl solution, the NaCl salt adsorption capacity of the cell was 23.6±2.2 mg/g which is equivalent to 35.7±3.3 mg/g as normalized to the mass of the MWCNT-hV2O5 electrode. Additionally, we propose a normalization method for the electrode material with Faradaic reactions based on sodium uptake capacities.
      PubDate: 2017-07-25T03:00:34.188848-05:
      DOI: 10.1002/cssc.201701215
  • 1D and 2D NMR spectroscopy of bonding interactions within stable and
           phase-separating organic electrolyte-cellulose solutions
    • Authors: Matthew T. Clough; Christophe Fares, Roberto Rinaldi
      Abstract: Organic electrolyte solutions (mixtures containing an ionic liquid and a polar, molecular co-solvent) are highly versatile solvents for cellu-lose. However, the underlying solvent-solvent and solvent-solute interactions are not yet fully understood. Herein, mixtures of the ionic liquid 1-ethyl-3-methylimidazolium acetate, the co-solvent 1,3-dimethyl-2-imidazolidinone, and cellulose are investigated using 1D and 2D NMR spectroscopy. The use of a triply-13C-labelled ionic liq-uid enhances the signal-to-noise ratio for 13C NMR spectroscopy, enabling changes in bonding interactions to be accurately pinpoint-ed. Current observations reveal an additional degree of complexity regarding the distinct roles of cation, anion and co-solvent toward maintaining cellulose solubility and phase stability. Unexpectedly, the interactions between the dialkylimidazolium ring C2-H substituent and cellulose become more pronounced at high temperatures, coun-teracted by a net weakening of acetate-cellulose interactions. More-over, for mixtures that exhibit critical solution behaviour, phase sepa-ration is accompanied by the apparent recombination of cation-anion pairs.
      PubDate: 2017-07-24T04:20:23.797875-05:
      DOI: 10.1002/cssc.201701042
  • Nanofiltration-enabled in situ solvent and reagent recycle for sustainable
           continuous-flow synthesis
    • Authors: Tamas Fodi; Christos Didaskalou, Jozsef Kupai, Gyorgy T Balogh, Peter Huszthy, Gyorgy Szekely
      Abstract: The solvent usage in the pharmaceutical sector accounts for as much as 90% of the overall mass during manufacturing processes. Consequently, solvent consumption poses significant costs and environmental burden. Continuous processing, in particular continuous-flow reactors have a great potential in the sustainable production of pharmaceuticals but subsequent downstream processing remains challenging. Separation processes for the concentration and purification of chemicals can account for as much as 80% of the total manufacturing costs. In this work, a nanofiltration unit was coupled to a continuous-flow rector for in situ solvent and reagent recycle. The nanofiltration unit is straightforward to implement and control in a continuous operation. The hybrid process was continuously operated over 6 weeks recycling about 90% of the solvent and the reagent. Consequently, the E factor and the carbon footprint were reduced by 91% and 19%, respectively. Moreover, the nanofiltration unit concentrated the product 11 times and simultaneously increased the purity from 52.4% to 91.5%. The boundaries for process conditions were investigated to facilitate implementation of the methodology by the pharmaceutical sector.
      PubDate: 2017-07-23T21:30:52.310444-05:
      DOI: 10.1002/cssc.201701120
  • Conducting Polymers Crosslinked with Sulfur as Cathode Materials for
           High-Rate, Ultralong-Life Lithium-Sulfur Batteries
    • Authors: Ligui Li; Shuaibo Zeng, Lihong Xie, Dengke Zhao, Nan Wang, Shaowei Chen
      Abstract: Low electrical conductivity and lack of chemical confinement are two major factors that limit the rate performance and cycling stability of cathode materials in lithium-sulfur (Li-S) batteries. Herein, sulfur is copolymerized with poly(m-aminothiophenol) (PMAT) nanoplates via inverse vulcanization, leading to a highly crosslinked copolymer cp(S-PMAT) in which about 80 wt% of the feeding sulfur is chemically bonded with the thiol groups of PMAT. The cp(S-PMAT)/C based cathode exhibits a high discharge capacity of 1240 mAh g-1 at 0.1 C, remarkable rate capacity of 880 mAh g-1 at 1 C and 600 mAh g-1 at 5 C; moreover, it can retain a capacity of 495 mAh g-1 after 1000 deep discharge-charge cycles at 2 C, corresponding to a retention of 66.9% and a decay rate of only 0.040% per cycle. Such a remarkable rate performance is attributed to the highly conductive pathways consisting of PMAT nanoplates, while the excellent cycling stability is mainly ascribed to chemical confinement of sulfur with a large number of stable covalent bonds between sulfur and thiol groups of PMAT. The results suggest a viable paradigm in the design and engineering of conducting polymers with reactive functional groups as effective electrode materials for high-performance Li-S batteries.
      PubDate: 2017-07-23T21:30:33.200331-05:
      DOI: 10.1002/cssc.201700913
  • Impact of Interfacial Layers in Perovskite Solar Cells
    • Authors: An-Na Cho; Nam-Gyu Park
      Abstract: Perovskite solar cell (PCSs) is composed of organic-inorganic lead halide perovskite as light harvester. Since the first report on long-term durable 9.7% efficient solid-state perovskite solar cell in 2012, organic-inorganic halide perovskite received great attention because of its superb opto-electronic properties. As a result, a power conversion efficiency (PCE) exceeding 22% was certified. Controlling grain size and grain boundary of perovskite layer perovskite is important for attaining high efficiency. In addition, interfacial engineering is equally or more important to improve further PCE via better charge collection and reduction in charge recombination. In this article, type of interfacial layers and their impacts on photovoltaic performance are investigated for the normal and inverted architectures. Grain boundary engineering is also included because it is related to interfacial engineering and grain boundary in perovskite layer plays important role in charge conduction, recombination and carrier life time.
      PubDate: 2017-07-23T21:30:22.262051-05:
      DOI: 10.1002/cssc.201701095
  • Stabilizing the performance of high-capacity sulfur composite electrodes
           by a novel gel polymer electrolyte configuration
    • Authors: Marco Agostini; Du Hyun Lim, Matthew Sadd, Fasciani Chiara, Maria Assunta Navarra, Stefania Panero, Sergio Brutti, Aleksandar Matic, Bruno Scrosati
      Abstract: Increased pollution and the consequent increasing in global warming are drawing attention to the larger use of renewable energy sources such as solar or wind. However, the production of energy from most renewable sources is intermittent and thus relies on the availability of electrical energy storage systems with high capacity and at competitive cost. Lithium-sulfur batteries are among the most promising technologies in this respect due to a very high theoretical energy density (1675 mAh g-1) and that the active material, S, is abundant and cheap. However, a so far limited practical energy density, life time and the scaling-up of materials and production processes prevent their introduction into commercial applications. In this work we report on a simple strategy to address these issues by using a novel gel polymer electrolyte (GPE) which enables stable performance close to the theoreticalof a low cost sulfur-carbon composite with high active material loading, i.e. 70% S. We show that the GPE prevents sulfur dissolution and reduces migration of polysulfide species to the anode. This functional mechanism of the GPE membranes is revealed investigating the Li-anode/GPE interphase at various state of discharge/charge using Raman spectroscopy.
      PubDate: 2017-07-21T09:10:26.201256-05:
      DOI: 10.1002/cssc.201700977
  • Vinylation of Aryl Ether (Lignin β-O-4 Linkage) and Epoxides with Calcium
           Carbide via C-O Bond Cleavage
    • Authors: Yugen Zhang; Siew Ping Teong, Jenny Lim
      Abstract: Calcium carbide has been increasingly used as a sustainable, easy-to-handle, and low-cost feedstock in organic synthesis. Currently, methodologies of using calcium carbide as "solid acetylene" in synthesis are strictly limited to activation and reaction with X-H (X = C, N, O, S) bonds. Herein, a mild and transition metal-free protocol was developed for the vinylation of epoxides and aryl ether linkage (β-O-4 lignin model compound) with calcium carbide via C-O bond cleavage, forming valuable vinyl ether products. CaC2 plays a vital role in the C-O bond activation and cleavage, and in providing acetylide source for the formation of vinylated products. These exciting results may provide new methodologies for organic synthesis and new insights towards lignin or biomass-related degradation to useful products.
      PubDate: 2017-07-20T21:16:34.259859-05:
      DOI: 10.1002/cssc.201701153
  • Plasmonic Gold Nanostars Incorporated into High-Efficiency Perovskite
           Solar Cells
    • Authors: Munkhbayar Batmunkh; Thomas Macdonald, William Peveler, Abdulaziz Bati, Claire J. Carmalt Claire J. Carmalt, Ivan Parkin, Joseph George Shapter
      Abstract: Incorporating appropriate plasmonic nanostructures into photovoltaic (PV) systems is of great utility for enhancing photon absorption and thus improving device performance. Herein, the successful integration of plasmonic gold nanostars (AuNSs) into mesoporous TiO2 photoelectrodes for perovskite solar cells (PSCs) is reported. The PSCs fabricated with TiO2-AuNSs photoelectrodes exhibited a device efficiency of up to 17.72%, while the control cells without AuNSs showed a maximum efficiency of 15.19%. We attribute the origin of increased device performance to enhanced light absorption and suppressed charge recombination.
      PubDate: 2017-07-20T10:10:29.212744-05:
      DOI: 10.1002/cssc.201701056
  • Corrigendum: Sustainable Gel Electrolyte Containing Pyrazole as Corrosion
           Inhibitor and Dendrite Suppressor for Aqueous Zn/LiMn2O4 Battery
    • Authors: Tuan K. A. Hoang; The Nam Long Doan, Julie Hyeonjoo Cho, Jane Ying Jun Su, Christine Lee, Changyu Lu, P. Chen
      PubDate: 2017-07-20T07:55:22.21873-05:0
      DOI: 10.1002/cssc.201701244
  • C-H carboxylation of aromatic compounds via CO2 fixation
    • Authors: Junfei Luo; Igor Larrosa
      Abstract: Carbon dioxide (CO2) represents the most abundant and accessible carbon source in Earth. Thus the ability to transform CO2 into valuable commodity chemicals via construction of C-C bonds is an invaluable strategy. Carboxylic acids and derivatives, the main products obtained by carboxylation of carbon nucleophiles by reaction of CO2, have wide application in pharmaceuticals and advanced materials. Among the variety of carboxylation methods currently available, the direct carboxylation of C-H bonds with CO2 has attracted much attention due to its advantages from a step- and atom-economical point of view. In particular, the prevalence of (hetero)aromatic carboxylic acid and derivatives among biologically active compounds has led to significant interest in the development of methods for their direct carboxylation from CO2. In this review will discuss the latest achievements in the area of direct C-H carboxylation of (hetero)aromatic compounds with CO2.
      PubDate: 2017-07-19T09:10:46.09985-05:0
      DOI: 10.1002/cssc.201701058
  • In-Situ Growth and Wrapping of Aminoanthraquinone Nanowires within 3D
           Graphene Framework as High-Performance Foldable Organic Cathode for
           Lithium Ion Batteries
    • Authors: Guanhui Yang; Fanxing Bu, Yanshan Huang, Yu Zhang, Imran Shakir, Yuxi Xu
      Abstract: Small conjugated carbonyl compounds are intriguing candidates of organic electrode materials because of their abundance, high theoretical capacity and adjustable molecular structure. However, their dissolution in aprotic electrolytes and poor conductivity eclipse them in terms of practical capacity, cycle life and rate capability. Herein, we report a foldable and binder-free nanocomposite electrode consisting of 2-aminoanthraquinone (AAQ) nanowires wrapping within three-dimensional (3D) graphene framework, which is prepared through antisolvent crystallization followed by a facile chemical reduction and self-assembly process. The nanocomposite exhibited a very high capacity of 265 mAh g-1 at 0.1 C for the AAQ, realizing 100% utilization of active material. Furthermore, the nanocomposite shows superior cycling stability (82% capacity retention after 200 cycles at 0.2 C and 76% capacity retention after 1000 cycles at 0.4 C) and excellent rate performance (153 mAh g-1 at 5 C). Particularly, the nanocomposite can deliver the highest capacity of 165 mAh g-1 among all reported anthraquinone and its analogues-based electrodes if based on the mass of the whole electrode, which is essential for practical application. Such outstanding electrochemical performance could be largely attributed to the wrapping structure of the flexible composite, which provides both conductivity and structural integrity.
      PubDate: 2017-07-19T00:30:30.793299-05:
      DOI: 10.1002/cssc.201701175
  • A Hydroxamic Acid Anchoring Group for Durable Dye-Sensitized Solar Cells
           with a Cobalt Redox Shuttle
    • Authors: Tomohiro Higashino; Yuma Kurumisawa, Ning Cai, Yamato Fujimori, Yukihiro Tsuji, Shimpei Nimura, Daniel Packwood, Jaehong Park, Hiroshi Imahori
      Abstract: A hydroxamic acid group has been employed for the first time as an anchoring group for cobalt-based dye-sensitized solar cells (DSSCs). The porphyrin dye YD2-o-C8HA with the hydroxamic acid anchoring group exhibited a power conversion efficiency (η) of 6.4%, which is close to that of YD2-o-C8, a representative porphyrin dye with a conventional carboxylic acid one. More importantly, YD2-o-C8HA was found to be superior to YD2-o-C8 in terms of both binding ability to TiO2 and durability of cobalt-based DSSCs. Notably, YD2-o-C8HA cell revealed a higher η-value (4.1%) than YD2-o-C8 (2.8%) after 500 h illumination. These results exemplify that the hydroxamic acid can be used for DSSCs with any transition metal-based redox shuttle to ensure high cell durability as well as excellent photovoltaic performance.
      PubDate: 2017-07-18T23:35:44.153038-05:
      DOI: 10.1002/cssc.201701157
  • A new perspective on transparent wood: Lignin-retaining transparent wood
    • Authors: Yuanyuan Li; Qiliang Fu, Ramiro Rojas, Min Yan, Martin Lawoko, Lars Berglund
      Abstract: Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30 wt% of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time consuming and not environmentally benign. Meanwhile, lignin removal weakens the wood structure, limiting the fabrication of large structure. Here, a green and industrially feasible method was introduced to prepare transparent wood. Up to 80 wt% of lignin was preserved, leading to a stronger wood template compared to the delignified alternative. After polymer infiltration, a high lignin content transparent wood with transmittance of 83%, haze of 75%, thermal conductivity of 0.23 W/mK, and work-to-fracture of 119.5 J/m3 (a magnitude higher than glass) was obtained. This transparent wood preparation method is efficient and applicable to various wood species. The transparent wood obtained is positioned for energy saving buildings.
      PubDate: 2017-07-18T09:50:17.458518-05:
      DOI: 10.1002/cssc.201701089
  • In-situ preparation of novel
           layered-spinel-microsphere/reduced-graphene-oxide heterostructured cathode
           for ultrafast charge-discharge Li-ion batteries
    • Authors: Dong Luo; Shaohua Fang, Li Yang, Shin-ichi Hirano
      Abstract: Although Li-rich layered oxides (LLOs) have the highest capacity of any cathodes used at present, their current rate capability is far from meeting the requirements of electric vehicles and smart grids. Here, a novel layered-spinel-microsphere/rGO (LS@rGO) heterostructured cathode is prepared by in-situ technique. This cathode is composed of a spinel phase, two layered structures and a few of reduced graphene oxide (rGO, 1.08 wt% of carbon). It delivers a considerably competitive capacity (145 mA h g-1) at an ultrahigh charge-discharge rate of 60 C (12 A g-1). The ultra-superior rate capability of LS@rGO is closely related with the in-situ introduction of spinel phase and rGO. Moreover, XAS and XPS data indicate Cr ions move from octahedral lattice sites to tetrahedral lattice sites and Mn ions do not participate in the oxidation reaction during the initial charge process.
      PubDate: 2017-07-17T22:16:23.479071-05:
      DOI: 10.1002/cssc.201701207
  • Metal–Organic Framework-Derived FeCo-N-Doped Hollow Porous Carbon
           Nanocubes for Electrocatalysis in Acidic and Alkaline Media
    • Authors: Xinzuo Fang; Long Jiao, Shu-Hong Yu, Hai-Long Jiang
      Abstract: Metal–organic frameworks (MOFs) are ideal precursors/ templates for porous carbons with homogeneous doping of active components for energy storage and conversion applications. Herein, metalloporphyrinic MOFs, PCN-224-FeCo, with adjustable molar ratio of FeII/CoII alternatively residing inside the porphyrin center, were employed as precursors to afford FeCo-N-doped porous carbon (denoted as FeCo-NPC) by pyrolysis. Thanks to the hollow porous structure, the synergetic effect between highly dispersed FeNx and CoNx active sites accompanied with a high degree of graphitization, the optimized FeCo2-NPC-900 obtained by pyrolysis at 900 °C exhibits more positive half-wave potential, higher diffusion-limited current density, and better stability than the state-of-the-art Pt/C, under both alkaline and acidic media. More importantly, the current synthetic approach based on MOFs offers a rational strategy to structure- and composition-controlled porous carbons for efficient electrocatalysis.Double-sided cubes: Porphyrinic metal–organic frameworks are employed to produce hollow porous carbon nanocubes with homogeneous FeNx and CoNx dopants by pyrolysis. Thanks to this particular structure, high surface area and synergetic contributions between FeNx and CoNx, the optimized FeCo2-NPC-900 exhibits excellent activity, long-term stability, and MeOH tolerance, surpassing the Pt/C, toward oxygen reduction electrocatalysis in both acidic and alkaline media.
      PubDate: 2017-07-17T06:45:54.410337-05:
      DOI: 10.1002/cssc.201700864
  • A multi-objective optimisation including results of life cycle assessment
           in developing bio-renewables-based processes
    • Authors: Daniel Helmdach; Polina Yaseneva, Parminder K Heer, Artur M Schweidtmann, Alexei Lapkin
      Abstract: A decision support tool has been developed, which uses global multi-objective optimisation based on: (i) the environmental impacts, evaluated within the framework of full life cycle assessment, and (ii) process costs, evaluated using rigorous process models. This approach is particularly useful in developing the bio renewable-based energy solutions and chemicals manufacturing, where multiple criteria must be evaluated and where the optimisation-based decision making process is particularly attractive. The framework is demonstrated using a case study of conversion of terpenes derived from bio-waste feedstocks into reactive intermediates. A two-step chemical conversion/separation sequence was implemented as a rigorous process model and combined with a life cycle model. A life cycle inventory for crude sulfate turpentine was developed, as well as a conceptual process of its separation into pure terpene feedstocks. The performed single- and multi-objective optimisations demonstrate the functionality of the optimisation-based process development and illustrate the approach. Most significant advance is the ability to perform multi-objective global optimisation, resulting in identification of a region of Pareto-optimal solutions.
      PubDate: 2017-07-17T06:16:09.535518-05:
      DOI: 10.1002/cssc.201700927
  • One-Step Cationic Grafting of 4-Hydroxy-TEMPO and its Application in a
           Hybrid Redox Flow Battery with a Crosslinked PBI Membrane
    • Authors: Zhenjun Chang; Dirk Henkensmeier, Ruiyong Chen
      Abstract: By using a one-step epoxide ring-opening reaction between 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (4-hydroxy-TEMPO) and glycidyltrimethylammonium cation (GTMA+), we synthesize a cation-grafted TEMPO (g+-TEMPO) and study its electrochemical performance against a Zn2+/Zn anode in a hybrid redox flow battery. To conduct Cl- counter anions, a crosslinked methylated polybenzimidazole (PBI) membrane was prepared and placed between the catholyte and anolyte. Compared to 4-hydroxy-TEMPO, the positively charged g+-TEMPO exhibits enhanced reaction kinetics. Moreover, flow battery tests with g+-TEMPO show improved coulombic, voltage and energy efficiencies and cycling stability over 140 cycles. Crossover of active species through the membrane was not detected.
      PubDate: 2017-07-17T02:15:32.534915-05:
      DOI: 10.1002/cssc.201701060
  • Decorating separator with macro/mesoporous Co-N-C for highly efficient
           polysulfides confinement and reutilization in lithium-sulfur batteries
    • Authors: Wen Hu; Yuichiro Hirota, Yexin Zhu, Nao Yoshida, Manabu Miyamoto, Tao Zheng, Norikazu Nishiyama
      Abstract: A macro/mesoporous Co-N-C-decorated separator is proposed to confine and reutilize migrating polysulfides. Endowed with desirable structure and synchronous lithio/sulfiphilic chemistry, macro/mesoporous Co-N-C interface manipulates large polysulfides adsorption uptake, high polysulfides adsorption kinetics, reversible electrocatalysis toward anchored-polysulfides redox, and facile charge transport. It significantly boosts simple MWCNT/S-70wt% cathode achieving high initial capacities (e.g. 1406 mAh g-1 at 0.2 C, 1203 mAh g-1 at 1 C), nearly 100% Coulombic efficiencies, and high reversible capacities after cycle tests (e.g. 828.4 mAh g-1 at 1 C after 100 cycles) at both low and high current rates. These results demonstrate that decorating separator with macro/meso Co-N-C paves a feasible way for developing advanced Li-S batteries.
      PubDate: 2017-07-14T05:25:35.777488-05:
      DOI: 10.1002/cssc.201700999
  • Low dimensional organic-inorganic halide perovskite: structure,
           properties, and applications
    • Authors: Ravi K.Misra; Bat-El Cohen, Lior Iagher, Lioz Etgar
      Abstract: Three-dimensional (3D) perovskite has attracted a lot of attention due to its success in photovoltaic (PV) solar cells. However, one the major crucial issues lies in its stability, which has limited its commercialization. An important property of organic-inorganic perovskite is the possibility of forming a layered material using long organic cations that do not fit into the octahedral cage. The long organic cation acts as a "barrier" that "caps" the 3D perovskite forming the layered material. Controlling the number of perovskite layers could provide a confined structure with different chemical and physical properties than 3D perovskite has. This opens up a whole new batch of interesting materials with huge potential for optoelectronic applications. This mini review presents the synthesis, properties, and structural orientation of low-dimensional perovskite. It also discusses the progress of low-dimensional perovskite in PV solar cells, which, to date, have a comparable performance but with enhanced stability in comparison with the 3D perovskite. Finally, the use of low-dimensional perovskite in LEDs and photodetectors is discussed. The low-dimensional perovskites are promising candidates for LED devices, mainly due to their high radiative recombination as a result of the confined low-dimensional quantum well.
      PubDate: 2017-07-13T10:25:26.032361-05:
      DOI: 10.1002/cssc.201701026
  • Hybrid deep eutectic solvents with flexible hydrogen-bonded supramolecular
           network for highly efficient uptake of NH₃
    • Authors: Yuhui Li; Mohammad Chand Ali, Qiwei Yang, Zhiguo Zhang, Zongbi Bao, Baogen Su, Huabin Xing, Qilong Ren
      Abstract: The serious environmental problems of modern society creates a great demand for the efficient uptake of NH₃ by solvents. However, many shortcomings exist with the traditional aqueous absorbents, and efforts to use ionic liquids met limited success. In this work, we for the first time report that the design of hybrid deep eutectic solvents (DESs) with flexible hydrogen-bonded supramolecular network enabled both exceptional NH₃ uptake capacity and superior desorption-regeneration performance, along with superb NH₃/CO₂ selectivity and environmental merits. Elucidated by the molecular dynamic simulations and spectrum analysis, the abundant hydrogen-bonding sites in the hybrid DESs grasp the every atom of NH₃ molecule and enable a strong physical reversible solvation, while the multiple interactions among the hybrid components create a flexible hydrogen-bonded supramolecular network and allow for solvent-unbreaking absorption to ensure the full participation of solvent and process stability. A mass solubility of NH₃ up to 0.13 gg-¹ was achieved at 313 K and 101 kPa by the hybrid DES choline chloride/resorcinol/glycerol (1:3:5), higher than all reported ionic liquids and ordinary DESs, and the performance remained the same after ten absorption-desorption cycles with easy regeneration. These results set a new benchmark for the reversible NH₃ absorption and separation by solvents, and would also inspire the more applications of DESs.
      PubDate: 2017-07-13T06:25:23.35114-05:0
      DOI: 10.1002/cssc.201701135
  • Efficient Electron Transfer across ZnO-MoS2-RGO Heterojunction for
           Remarkably Enhanced Sunlight Driven Photocatalytic Hydrogen Evolution
    • Authors: Suneel Kumar; Nagappagari Lakshmana Reddy, Himmat Singh Kushwaha, Ashish Kumar, Muthukonda Venkatakrishnan Shankar, Kaustava Bhattacharyya, Aditi Halder, Venkata Krishnan
      Abstract: Development of noble metal free catalysts for hydrogen evolution is the need of the hour for energy applications. In this regard, we designed and synthesized ternary heterojunction nanocomposites, consisting of ZnO nanoparticles anchored on MoS2-RGO nanosheets, as heterogeneous catalysts for highly efficient photocatalytic hydrogen (H2) evolution. In photocatalytic process, catalyst dispersed in electrolytic solution (S2-, SO32-) recorded an enhanced rate of H2 evolution and the optimization experiments reveals that ZnO with 4.0 wt% of MoS2-RGO nanosheets (ZMG4) showed the highest photocatalytic H2 production of 28.616 mmol h-1 gcat-1 under sunlight irradiation, which is about 56 times higher than bare ZnO and several times higher than other ternary photocatalysts. The superior catalytic activity can be attributed to in situ generation of ZnS, which leads to improved interfacial charge transfer to cocatalyst MoS2, in turn RGO where plenty of active sites available for photocatalytic reaction. The recyclability experiments of optimized photocatalyst proved its stability. In addition, the ternary nanocomposites also show its multi-functional properties for hydrogen evolution activity under electrocatalytic and photoelectrocatalytic conditions due to the high electrode-electrolyte contact area. Thus, the present work provides very useful insights in the development of inexpensive, multi-functional catalysts without noble metal loading to achieve high rate of H2 generation.
      PubDate: 2017-07-13T05:30:34.331303-05:
      DOI: 10.1002/cssc.201701024
  • Poly(ethylene glycol)s as Ligands in Calcium-Catalyzed Cyclic Carbonate
    • Authors: Johannes Steinbauer; Thomas Werner
      Abstract: Herein the use of CaI2 in combination with poly(ethylene glycol) dimethyl ether (PEG DME 500) as an efficient catalyst system for the addition of CO2 to epoxides is reported. This protocol is based on a nontoxic and abundant metal in conjunction with a polymeric ligand. Fifteen terminal epoxides were converted at room temperature to give the desired products in yields up to 99 %. Notably, this system was also effective for the synthesis of twelve challenging internal carbonates in yields up to 98 %.Ca-talysis: Calcium-based catalyst systems using inexpensive and biocompatible ligands for the synthesis of cyclic carbonates from epoxides and CO2 are reported. This scalable reaction protocol can be used for the synthesis of terminal carbonates at room temperature as well as for the synthesis of internal carbonates below 100 °C.
      PubDate: 2017-07-12T01:08:55.682103-05:
      DOI: 10.1002/cssc.201700788
  • Conversion of cellulose to amphiphilic alkyl glycosides catalyzed by
           Aquivion, a perfluorosulfonic acid polymer
    • Authors: François Jérôme; Karine De Oliveira Vigier, Ayman Karam, Boris Estrine, Sinisa Marincovic, Claudio Oldani
      Abstract: Aquivion PFSA PW98 is an amphiphilic solid superacid capable of converting cellulose to Amphiphilic Alkyl Glycosides (AAG) in 85% yield (i.e. 97% selectivity). The present process involves (1) a mechanocatalytic depolymerization of cellulose followed by (2) a direct glycosylation with n-dodecanol. In comparison to H2SO4 and solid acid catalysts commonly employed in cellulose processing, Aquivion PFSA PW98 is not only recyclable but also exhibits superior catalytic performances in terms of yield, selectivity and reactor productivity
      PubDate: 2017-07-11T05:43:54.064286-05:
      DOI: 10.1002/cssc.201700903
  • Homologous Catalysts Based on Fe-Doped CoP Nanoarray toward
           High-Performance Full Water Splitting under Benign Conditions
    • Authors: Min Ma; Guilei Zhu, Fengli Qu, Zhiang Liu, Gu Du, Abdullah M. Asiri, Yadong Yao, Xuping Sun
      Abstract: The design and development of earth-abundant electrocatalysts for efficient full water splitting under mild conditions are highly desired but still remain a challenging task. In this study, we describe the development of homologous Fe-doped Co-based nanoarray as complementary catalysts for high-performance and durable water splitting in near-neutral media. Fe-doped Co-phosphate-borate nanoarray on carbon cloth (Fe-Co-Pi-Bi/CC) derived from Fe-doped CoP nanoarray on CC (Fe-CoP/CC) via oxidative polarization behaves as a highly active bimetallic electrocatalyst for water oxidation with the demand of overpotential of 382 mV to afford a geometrical catalytic current density of 10 mA cm-2 in 0.1 M potassium borate (K-Bi, pH: 9.2). Fe-CoP/CC is also superior in activity for hydrogen evolution reaction, capable of driving 10 mA cm-2 at overpotential of only 175 mV in 0.1 M K-Bi. The two-electrode water electrolyser using Fe-Co-Pi-Bi/CC as anode and Fe-CoP/CC as cathode achieves 10 mA cm-2 water splitting current at a cell voltage of 1.95 V with strong long-term electrochemical durability.
      PubDate: 2017-07-10T10:41:47.819842-05:
      DOI: 10.1002/cssc.201700693
  • Cooking with active oxygen and solid alkali (CAOSA): a promising
           alternative approach for lignocellulosic biorefineries
    • Authors: Yetao Jiang; Xianhai Zeng, Rafael Luque, Xing Tang, Yong Sun, Tingzhou Lei, Shijie Liu, Lu Lin
      Abstract: Lignocellulosic biomass, a matrix of the biopolymers including cellulose, hemicellulose and lignin, has gathered increasing attention in recent years in the production of chemicals, fuels and materials based on biorefinery processes due to its renewability and availability. Fractionating lignocellulose is considered as the foundational step to establish an economical and sustainable lignocellulosic biorefinery. This Minireview summarized a newly developed oxygen delignification for lignocellulose fractionation called cooking with active oxygen and solid alkali (CAOSA), which could fractionate lignocellulose into its constituents while remaining in processable form. In the CAOSA approach, environmentally-friendly chemicals were applied instead of undesirable chemicals including strong alkalis and sulfides. Notably, the alkali recovery for this process promised to be relatively simple, neither causticizing nor sintering. These features made the CAOSA process an alternative for both lignocellulose fractionation and biomass pretreatment. Advantages and challenges have also been discussed in order to provide a comprehensive perspective with respect to existing strategies.
      PubDate: 2017-07-10T06:15:22.111817-05:
      DOI: 10.1002/cssc.201700906
  • Influence of the Water Phase State on the Thermodynamics of Aqueous Phase
           Reforming for Hydrogen Production
    • Authors: Séverine Le Gac; Renée M Ripken, Jan Meuldijk, Johannes G.E. Gardeniers
      Abstract: Abstract: Hydrogen is a promising renewable energy source that can be produced from biomass using Aqueous Phase Reforming (APR). Here, using data obtained from AspenPlus and the literature, we evaluated the phase state, temperature-dependent enthalpy, and Gibbs free energy for the APR of small biomass model substrates. Phase equilibrium studies reveal that, under typical APR reaction conditions, the reaction mixture is in the liquid phase. Therefore, we show for the first time that the water-gas-shift (WGS), which is the second main reaction of APR, must be modeled in the liquid phase, resulting in an endothermic instead of an exothermic enthalpy of reaction. A significant implication of this finding is that, although APR has been introduced as more energy saving than conventional reforming methods, the WGS in APR has a comparable energy demand to the WGS in steam reforming (SR).
      PubDate: 2017-07-10T04:15:42.924986-05:
      DOI: 10.1002/cssc.201700189
  • Prominent Electron Penetration through Ultrathin Graphene Layer from FeNi
           Alloy for Efficient Reduction of CO2 to CO
    • Authors: Qingyuan Bi; Xin Wang, Feng Gu, Xianlong Du, Hongliang Bao, Guoheng Yin, Jianjun Liu, Fu-Qiang Huang
      Abstract: The chemical transformation of CO2 is an efficient approach in low-carbon energy system. The development of non-precious metal catalysts with sufficient activity, selectivity, and stability for the generation of CO by CO2 reduction under mild conditions remains a major challenge. Herein, we report a hierarchical architecture catalyst composed of ultrathin graphene shells (2-4 layers) encapsulating homogeneous FeNi alloy nanoparticles to enhance the catalytic performance. The electron transfer from the encapsulated alloy can extend from the inner to the outer shell, resulting in an increased charge density on graphene. Nitrogen atom dopants can synergistically increase the electron density on the catalyst surface and modulate the adsorption capability for acidic CO2 molecules. The optimized FeNi3@NG with prominent electron penetration through the graphene layer exhibits an excepti-onal CO2 conversion of 20.2% with a CO selectivity of nearly 100%, as well as excellent thermal stability at 523 K.
      PubDate: 2017-07-10T02:15:23.37386-05:0
      DOI: 10.1002/cssc.201700787
  • High Efficiency MAPbI3 Perovskite Solar Cell Using a Pure Thin Film of
           Polyoxometalate as Scaffold Layer
    • Authors: Mohammad Khaledi Sardashti; Mahmoud Zendehdel, Narges Yaghoobi Nia, Davud Karimian, Mohammad Sheikhi
      Abstract: In this work, we successfully used a pure layer of [SiW11O39]8- polyoxomethalate (POM) structure as a thin film scaffold layer of CH3NH3PbI3 based perovskite solar cells (PSCs). A smooth nanoporous surface of POM cause to amazing improvement of the photocurrent density, External Quantum Efficiency (EQE) and overall efficiency of the PSCs compare to mp-TiO2 as scaffold layer. Average PCE values of 15.5% with champion device as 16.3% could achieve by using POM and sequential deposition method of perovskite layer. Furthermore, modified and defect-free POM/perovskite interface led to elimination of the anomalous hysteresis in the current-voltage curves. Open-circuit voltage decay study show promising decrease of the electron recombination in the POM based PSCs which also related to modification of POM/perovskite interface and higher electron transport inside the POM layer.
      PubDate: 2017-07-07T23:25:56.281131-05:
      DOI: 10.1002/cssc.201701027
  • Catalytic Hydrodeoxygenation of High Carbon Furylmethanes to Renewable
           Jet-fuel Ranged Alkanes over a Rhenium Modified Iridium Catalyst
    • Authors: Basudeb Saha; Sibao Liu, Saikat Dutta, Weiqing Zheng, Nicholas S Gould, Ziwei Cheng, Bingjun Xu, Dionisios G Vlachos
      Abstract: Renewable jet-fuel ranged alkanes are synthesized by hydrodeoxygenation of lignocellulose derived high carbon furylmethanes over ReOx modified Ir/SiO2 catalysts under mild reaction conditions. Ir-ReOx/SiO2 with a Re/Ir molar ratio of 2 exhibits the best performance, achieving a combined alkanes yield of 82-99% from C12-C15 furylmethanes. Catalyst can be regenerated in three consecutive cycles with only ~12% loss in the combined alkanes yield. Mechanistically, the furan moieties of furylmethanes undergo simultaneous ring saturation and ring opening to form a mixture of complex oxygenates consisting of saturated furan rings, mono-keto groups, and mono-hydroxy groups. Then, these oxygenates undergo a cascade of hydrogenolysis reactions to alkanes. The high yield of Ir-ReOx/SiO2 arises from a synergy between Ir and ReOx. The acidic sites of partially reduced ReOx activate the C-O bonds of the saturated furans and alcoholic groups, while the Ir sites are responsible for hydrogenation with H2.
      PubDate: 2017-07-07T10:21:11.208533-05:
      DOI: 10.1002/cssc.201700863
  • A comparative study of basic, amphoteric and acidic catalysts in the
           oxidative coupling of methanol and ethanol for acrolein production
    • Authors: Aleksandra Lilic; Tiantian Wei, Simona Bennici, Jean-François Devaux, Jean-Luc Dubois, Aline Auroux
      Abstract: The impact of acid/base properties (determined by adsorption microcalorimetry) of various catalysts on the cross-aldolization of acetaldehyde and formaldehyde leading to acrolein was methodically studied in oxidizing conditions starting from a mixture of methanol and ethanol. The aldol-condensation and further dehydration to acrolein were carried out on catalysts presenting various acid-base properties (MgO, Mg-Al, Mg-SiO2, NbP, and HPA-SiO2). Thermodynamic calculations revealed that cross-aldolization is always favored comparing to self-aldolization of acetaldehyde which leads to crotonaldehyde formation. The presence of strong basic sites is shown to be necessary, but a too high amount drastically increases COx production. On strong acid sites production of acrolein and carbon oxides (COx) does not increase with temperature. The optimal catalyst for this process should be amphoteric with a balanced acid-base cooperation of medium strength sites and a small amount (150 kJ mol-1).
      PubDate: 2017-07-07T09:21:27.141205-05:
      DOI: 10.1002/cssc.201701040
  • Concentration-gradient multi-channel flow stream membrane capacitive
           deionization cell for ultra-high desalination capacity of carbon
    • Authors: Choonsoo Kim; Juhan Lee, Pattarachai Srimuk, Mesut Aslan, Volker Presser
      Abstract: We present a novel multi-channel membrane flow stream capacitive deionization (MC-MCDI) concept with two flow streams to control the environment around the electrodes and a middle channel for water desalination. The introduction of side channels to our new cell design allows operation in a highly saline environment, while the feed water stream in the middle channel (conventional CDI channel) is separated from the electrodes with anion and cation exchange membranes. At a high salinity gradient between side (1000 mM) and middle (5 mM) channels, MC-MCDI exhibited an unprecedented salt adsorption capacity (SAC) of 56 mg/g in the middle channel with charge efficiency close to unity and low energy consumption. This excellent performance corresponds to a four-fold increase in desalination performance compared to the state-of-the-art in a conventional CDI cell. The enhancement originates from the enhanced specific capacitance in high molar saline media in agreement with the Gouy-Chapman-Stern theory and from a double ion desorption/adsorption process of MC-MCDI via voltage operation from -1.2 V to +1.2 V.
      PubDate: 2017-07-07T06:20:28.630583-05:
      DOI: 10.1002/cssc.201700967
  • Prospective Symbiosis of Green Chemistry and Energetic Materials
    • Authors: Ilya V. Kuchurov; Mikhail N. Zharkov, Leonid L. Fershtat, Nina N. Makhova, Sergei G. Zlotin
      Abstract: A global increase in the environmental pollution demands the development of new "cleaner" chemical processes. Among urgent improvements, replacement of traditional hydrocarbon-derived toxic organic solvents with neoteric solvents less harmful for the environment is one of the most vital issues. Due to favorable combination of unique properties, ionic liquids (ILs), dense gases, and supercritical fluids (SCFs) have gained considered attention as suitable green chemistry media for preparation and modification of important chemical compounds and materials. In particular, they have a significant potential in a specific and very important area of research which is associated with manufacturing and processing of high-energy materials (HEMs). These large-scale manufacturing processes, in which hazardous chemicals and extreme conditions are used, produce a huge amount of hard-to-dispose waste. Furthermore, they are risky to staff and any improvements that would reduce fire and explosion risks of the corresponding processes are highly desirable. In this review, useful applications of almost non-flammable ILs, dense gases, and SCFs (first of all, carbon dioxide) for nitration and other reactions used for manufacturing of HEMs are considered. Recent advances in the field of energetic (oxygen-balanced and hypergolic) ILs are summarized. A significant attention is paid to the SCF-based micronization techniques, which improve energetic performance of HEMs via an efficient control of morphology and particle size distribution of the HEMs fine particles, and to useful applications of SCFs in HEM processing which makes them less hazardous.
      PubDate: 2017-07-06T09:20:30.114555-05:
      DOI: 10.1002/cssc.201701053
  • Electrocatalytic Water Oxidation Promoted by 3D Nano-architectured
           Turbostratic δ-MnOx on Carbon Nanotube
    • Authors: Licheng Sun; Biaobiao Zhang, Yuanyuan Li, Mario Valvo, Lizhou Fan, Quentin Daniel, Peili Zhang, Linqin Wang
      Abstract: Development of manganese based water oxidation electrocatalysts is desirable for the production of solar fuels, since manganese is earth-abundant, inexpensive, non-toxic and employed by the Photosystem II in nature for billion years. Herein, we have directly constructed a 3D nanoarchitectured turbostratic δ-MnOx on carbon nanotube-modified Ni foam (MnOx/CNT/NF) by electrodeposition and a subsequent annealing process. The MnOx/CNT/NF electrode gives a benchmark catalytic current density (10 mA/cm2) at an η of 270 mV under alkaline conditions. A steady current density of 19 mA/cm2 is obtained during the electrolysis at 1.53 V for 1.0 h. To the best of our knowledge, this work represents the most efficient manganese oxide based water oxidation electrode and demonstrates that manganese oxides, as a structural and functional model of oxygen-evolving complex (OEC) in Photosystem II, can also become comparable to those of most Ni- and Co-based catalysts.
      PubDate: 2017-07-04T07:20:29.04052-05:0
      DOI: 10.1002/cssc.201700824
  • Effect of nitrogen doping level on the performance of N-doped carbon
           quantum dot/TiO2 composites for photocatalytic hydrogen evolution
    • Authors: Run Shi; Zi Li, Huijun Yu, Lu Shang, Chao Zhou, Geoffrey I.N. Waterhouse, Li-Zhu Wu, Tierui Zhang
      Abstract: Carbon quantum dots (CQDs) attract widespread interest for photocatalytic applications due to their low cost and excellent electron donor/acceptor properties. However, their advance-ment as visible light photosensitizers in CQDs/semiconductor nanocomposites is currently impaired by their poor quantum yields (QYs). Herein, we describe the successful fabrication of a series of nitrogen-doped CQDs (NCDs) with N/C atom ratios ranging from 0.14-0.30. NCDs with the highest N-doping level afforded a remarkable external QY of 66.8 % at 360 nm, and outstanding electron transfer properties and photosensitiza-tion efficiencies when physically adsorbed on P25 TiO2. A NCDs/P25-TiO2 hybrid demonstrated excellent performance for hydrogen evolution in aqueous methanol under both UV and visible light illumination relative to pristine P25 TiO2. Controlled nitrogen doping of CQDs therefore represents a very effective strategy for optimizing the performance of CQDs/semiconductor hybrid photocatalysts.
      PubDate: 2017-07-03T04:16:08.392395-05:
      DOI: 10.1002/cssc.201700943
  • Factors influencing the mechanical properties of formamidinium lead
           halides and related hybrid perovskites
    • Authors: Shijing Sun; Furkan H. Isikgor, Zeyu Deng, Fengxia Wei, Gregor Kieslich, Paul D. Bristowe, Jianyong Ouyang, Anthony K. Cheetham
      Abstract: The mechanical properties of formamidinium lead halide perovskites (FAPbX3, X = Br or I) grown by inverse temperature crystallization have been studied by nanoindentation. The measured Young's moduli (9.7 - 12.3 GPa) and hardnesses (0.36 - 0.45 GPa) indicate good mechanical flexibility and ductility. The effects of hydrogen bonding were evaluated by performing ab initio molecular dynamics on both formamidinium and methylammonium perovskites and calculating radial distribution functions. The structural and chemical factors influencing these properties are discussed by comparison with corresponding values in the literature for other hybrid perovskites, including double perovskites. Our results reveal that bonding in the inorganic framework and hydrogen bonding play important roles in determining elastic stiffness. The influence of the organic cation becomes more important for structures at the limit of their perovskite stability, indicated by high tolerance factors.
      PubDate: 2017-06-30T12:05:47.291024-05:
      DOI: 10.1002/cssc.201700991
  • Efficient and Highly Selective Solvent-Free Oxidation of Primary Alcohols
           to Aldehydes Using Bucky Nanodiamond
    • Authors: Yangming Lin; Kuang-Hsu (Tim) Wu, Linhui Yu, Saskia Heumann, Dangsheng Su
      Abstract: Selective oxidation of alcohols to aldehydes is widely applicable to the synthesis of various green chemicals. The poor chemo-selectivity for complicated primary aldehydes over state-of-the-art metal-free or metal-based catalysts represents a major obstacle for industrial application. Here we report on bucky nanodiamond as a potential green catalyst which exhibits excellent chemo-selectivity and cycle stability in the selective oxidation of primary alcohols in diverse structures (22 examples, including aromatic, substituted aromatic, unsaturated, heterocycle and linear chain alcohols) to their corresponding aldehydes; the results are even comparable to the reported transition metal catalysts and conventional Pt/C and Ru/C catalysts for certain substrates under solvent-free conditions. The possible activation process of surface oxygen groups and defect species to oxidant and substrate are revealed with model catalysts, ex-situ electrochemical measurement and ex-situ attenuated total reflectance. The zigzag edges of sp2 carbon planes have been shown to play a key role in these reactions.
      PubDate: 2017-06-30T10:06:29.536421-05:
      DOI: 10.1002/cssc.201700968
  • Minimalistic Liquid-Assisted Route to Highly Crystalline α-Zirconium
    • Authors: Yu Cheng; Xiaodong (Tony) Wang, Stephan Jaenicke, Gaik-Khuan Chuah
      Abstract: Zirconium phosphates have potential applications in areas of ion-exchange, catalysis, photochemistry, and biotechnology. However, synthesis methodologies to form crystalline α-zirconium phosphate (Zr(HPO₄)₂·H₂O) typically involve the use of excess phosphoric acid, addition of HF or oxalic acid and long reflux times or hydrothermal conditions. Herein we report on a minimalistic sustainable route using only zirconium oxychloride and concentrated phosphoric acid to form highly crystalline α-zirconium phosphate within hours. The morphology can be changed from platelets to rod-shaped particles with fluoride addition. By varying the temperature and time, α-zirconium phosphate with particle sizes from nanometers to microns were obtained. Key features of this minimal solvent synthesis are the excellent yields obtained with high atom economy under mild conditions and ease of scalability.
      PubDate: 2017-06-30T08:05:19.693104-05:
      DOI: 10.1002/cssc.201700885
  • Impact of macroporosity on catalytic upgrading of fast pyrolysis bio-oil
           by esterification over silica sulfonic acids
    • Authors: Jinesh Manayil; Amin Osatiashtiani, Alvaro Mendoza, Christopher Parlett, Lee Durndell, Mark Isaacs, Chrysoula Michailof, Eleni Heracleous, Angelos Lappas, Adam Lee, Karen Wilson
      Abstract: Fast pyrolysis bio-oils possess unfavourable physicochemical properties and poor stability, due in large part to the presence of carboxylic acids, which hinders their use as biofuels. Catalytic esterification offers an atom and energy efficient route to upgrade pyrolysis bio-oils. Propyl sulfonic acid silicas are active for carboxylic acid esterification but suffer mass-transport limitations for bulky substrates. Macropore (200 nm) incorporation enhances the activity of mesoporous SBA-15 architectures (post-functionalised by hydrothermal saline promoted grafting) for the esterification of linear carboxylic acids, with the magnitude of turnover frequency (TOF) enhancement increasing with chain length from 5 % (C3) to 110 % (C12). Macroporous-mesoporous PrSO3H/SBA-15 also offers a two-fold TOF enhancement over its mesoporous analogue for the esterification of a real thermal fast pyrolysis bio-oil derived from woodchips. The total acid number was reduced by 57 %, with GCxGC-ToFMS evidencing ester and ether formation accompanying loss of acid, phenolic, aldehyde and ketone components.
      PubDate: 2017-06-30T05:05:52.099639-05:
      DOI: 10.1002/cssc.201700959
  • Hierarchical Hollow Covalent Organic Frameworks-derived Heteroatom-doped
           Carbon Spheres for Metal-free Catalysis
    • Authors: Liuyi Li; Lu Li, Caiyan Cui, Hongjun Fan, Ruihu Wang
      Abstract: Covalent organic frameworks (COFs) with hollow structures hold great promises for developing new types of functional materials. Herein, we report a hollow spherical COF with a hierarchical shell, which serves as an effective precursor of B,N-codoped hierarchical hollow carbon spheres. Benefiting from the synergistic effect of hierarchical porosity, high surface area and B,N-codoping, the as-synthesized carbon spheres show the prospective utility as metal-free catalysts in nitroarene reduction. A mechanistic hypothesis is proposed based on theoretical and experimental studies. B atoms meta to pyridinic N atoms are identified to be the main catalytic active sites. The anti-aromaticity originated from the codoping of B and pyridinic N atoms, not charge distribution and deformation energy, is corroborated to play a pivotal role in the catalytic reaction.
      PubDate: 2017-06-29T22:07:51.523633-05:
      DOI: 10.1002/cssc.201700979
  • Tuning the composition of bimetallic electrodeposited Sn-Pb catalysts for
           enhanced activity and durability in CO2 electroreduction to formate
    • Authors: Elod Gyenge; Colin Moore
      Abstract: Bimetallic Sn-Pb catalysts with five different Sn:Pb atomic ratios were electrodeposited on teflonated carbon paper and un-teflonated carbon cloth using both fluoroborate and oxide containing deposition media to produce catalysts for electrochemical reduction of CO2 (ERC) to formate (HCOO-). The interaction between catalyst composition, morphology, substrate and deposition media was investigated by cyclic voltammetry and constant potential electrolysis at -2.0 V vs. Ag/AgCl for 2 h in 0.5 M KHCO3. The catalysts were analyzed before and after electrolysis with scanning electron microscopy (SEM) and X-ray diffraction (XRD) to determine the mechanisms of faradaic efficiency loss and degradation. Sn majority catalysts with 15 to 35%at. Pb generated faradaic efficiencies up to 95% with stable performance. Pure Sn catalysts on the other hand, in spite of high initial stage formate production rates, experienced extensive (up to 30%) decrease of the faradaic efficiency. XRD results demonstrated the presence of polycrystalline SnO2 after electrolysis using Sn-Pb catalysts with 35%at. Pb and its absence in case of pure Sn. It is proposed that the presence of Pb (15 to 35 %at.) in Sn majority catalysts stabilized SnO2, which is responsible for the enhanced faradaic efficiency and catalytic durability in ERC.
      PubDate: 2017-06-29T21:06:26.653377-05:
      DOI: 10.1002/cssc.201700761
  • Benzoyl Peroxide as an Efficient Dopant for spiro-OMeTAD in Perovskite
           Solar Cells
    • Authors: Qiuju Liu; Lisheng Fan, An’an Zhou, Baozeng Wang, Hua Bai, Qingyong Tian, Bin Fan, Tongyi Zhang
      Abstract: Although organic small molecule spiro-OMeTAD is widely used as a hole transport material in perovskite solar cells, its limited electric conductivity might be a bottle-neck challenge in the efficiency improvement of perovskite solar cells. In this article, a low-cost and easy-fabrication technique is developed to enhance the conductivity and hole extraction of spiro-OMeTAD by doping it with commercially available benzoyl peroxide (BPO). The experimental results show that the conductivity increases many order in magnitude, from 6.2 × 10−6 S cm−1 of the pristine spiro-OMeTAD to 1.1 × 10−3 S cm−1 at the 5% BPO doping and to 2.4 × 10−2 S cm−1 at the 15% BPO doping, which considerably outperform the conductivity of 4.62 × 10−4 S cm−1 in the currently used oxygen doped spiro-OMeTAD. The fluorescence spectra suggest the BPO doped spiro-OMeTAD-OMeTAD layer is able to efficiently extract hole from the underneath CH3NH3PbI3 and thus greatly enhance the charge transfer. The BPO doped spiro-OMeTAD is used in the fabrication of perovskite solar cells, which exhibit the enhancement in the power conversion efficiency.
      PubDate: 2017-06-29T09:05:56.528281-05:
      DOI: 10.1002/cssc.201700872
  • Sulfur-Doped Graphene Oxide Quantum Dots as Photocatalysts for Hydrogen
           Generation in the Aqueous Phase
    • Authors: Tung-Kung Wu; Jacek Gliniak, Jia-Hoa Lin, Yi-Ting Chen, Chuen-Ru Li, Efat Jokar, Chin-Hao Chang, Chun-Sheng Peng, Jui-Nien Lin, Wan-Hsiang Lien, Hui-Min Tsai
      Abstract: Sulfur-doped graphene oxide quantum dots (S-GO QDs) have been synthesized and investigated for efficient photocatalytic hydrogen generation application. The UV‒vis, FT‒IR, and photoluminescent spectra of the synthesized S-GO QDs exhibit three absorption bands at 333, 395, and 524 nm, characteristic of C=S and C-S stretching vibration signals at 1075 cm-1 and 690 cm-1, and two excitation wavelength independent emission signals with maxima at 451 and 520 nm, respectively, confirming the successful doping of S atom into the GO QDs. Electronic structural analysis suggested that the S-GO QDs exhibit conduction band minimum (CBM) and valence band maximum (VBM) levels suitable for water splitting. Under direct sunlight irradiation, an initial rate of 18166 μmol∙h-1∙g-1 in pure water and 30519 μmol∙h-1∙g-1 in 80% EtOH aqueous solution were obtained. Therefore, metal-free and inexpensive S-GO QDs hold great potential in the development of sustainable and environmental-friendly photocatalysts for efficient hydrogen generation from water-splitting.
      PubDate: 2017-06-28T03:00:22.371752-05:
      DOI: 10.1002/cssc.201700910
  • Replacement of Biphenyl by Bipyridine Enabling Powerful Hole Transport
           Materials for Efficient Perovskite Solar Cells with High Voc and FF
    • Authors: Fei Wu; Yahan Shan, Jianhui Qiao, Cheng Zhong, Rui Wang, Qunliang Song, Linna Zhu
      Abstract: In this work, the 2,2'- and 3,3'-bipyridine are firstly introduced as the core structure to get two new hole transport materials, namely F22 and F33. The electron-withdrawing nature of bipyridine lowers the HOMO level of the new compounds, and increases Voc of the resulting solar cells. Especially for F33, the better planarity leads to better conjugation in the whole molecule, and the HOMO level is lowered by the bipyridine center compared to F22. Hole mobility tests, steady state PL spectra as well as time-resolved PL decay results, demonstrate that the new HTMs exhibit good hole extraction and hole transporting property. Impressive power conversion efficiency of 17.71 % and 18.48 % are achieved in conventional planar perovskite (CH3NH3PbI3-xClx) solar cells containing F22 and F33 as hole transport material, respectively. As far as we know, this is the first report on bypiridine-based HTMs with leading efficiencies, and the design motif in this work opens a new way for devising hole transport materials in the future.
      PubDate: 2017-06-27T21:00:57.78097-05:0
      DOI: 10.1002/cssc.201700973
  • Metal Free Oxidation of Glycerol over Nitrogen Containing Carbon Nanotubes
    • Authors: Alberto Villa; Neeraj Gupta, Oleksiy Khavryuchenko, Dangsheng Su
      Abstract: Nitrogen rich carbon nanotubes have been used as a metal free catalyst for the conversion of glycerol into dihydroxyacetone using tert-Butyl hydroperoxide (TBHP) as an oxidant. Pyridine nitrogen embedded in carbon matrix is identified as an active site for the reaction. Computational studies have demonstrated that oxidation of pyridine site to pyridine oxime followed by hydrogen abstraction from secondary alcohol is most probably responsible for the oxidation process.
      PubDate: 2017-06-27T11:00:37.182406-05:
      DOI: 10.1002/cssc.201700940
  • Low-cost Carbazole-based Hole Transport Material for Highly Efficient
           Perovskite Solar Cells
    • Authors: Zhiliang Chen; Hui Li, Xiaolu Zheng, Qi Zhang, Zhanfeng Li, Yuying Hao, Guojia Fang
      Abstract: A low cost carbazole based small molecule material 1,3,6,8-tetra(N,N-p-dimethoxyphenylamino)-9-ethyl-carbazole was designed and synthesized using a facile three-step synthetic route. The novel material was fully characterized and further applied as hole transport material (HTM) for low temperature processed planar perovskite solar cells (PSCs). Devices based on this new HTM exhibit a high power conversion efficiency (PCE) of 17.8%, which is comparable to that (PCE of 18.6%) of the costly 2,2',7,7'-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) based PSCs.
      PubDate: 2017-06-26T22:17:38.710381-05:
      DOI: 10.1002/cssc.201700678
  • Sustainable Biomass-Derived Catalysts for Selective Hydrogenation of
    • Authors: Basudev Sahoo; Dario Formenti, Christoph Topf, Stephan Bachmann, Michelangelo Scalone, Kathrin Junge, Matthias Beller
      Abstract: Development of catalytically active materials from biowaste represents an important aspect of sustainable chemical research. Three heterogeneous materials were synthesized from inexpensive biomass based chitosan and abundant Co(OAc)₂via complexation followed by pyrolysis at various temperatures. These materials were applied for the catalytic hydrogenation of nitroarenes using molecular hydrogen. A variety of diversely functionalized nitroarenes including few pharmaceutically active compounds were selectively converted to aromatic amines in high yield and selectivity with excellent functional group tolerance. As an example, this green protocol has also been implemented for the synthesis of biologically important TRPC3 inhibitor.
      PubDate: 2017-06-26T09:17:52.80268-05:0
      DOI: 10.1002/cssc.201700796
  • Anionic extraction for efficient recovery of bio-based 2,3-butanediol - a
           platform for bulk and fine chemicals
    • Authors: Peter Drabo; Till Tiso, Benedikt Heyman, Eda Sarikaya, Paula Gaspar, Jochen Förster, Jochen Büchs, Lars Mathias Blank, Irina Delidovich
      Abstract: 2,3-Butanediol (BDO) presents a promising platform molecule for the synthesis of basic and fine chemicals. Biotechnological production of BDO from renewable resources with living microbes enables high concentrations in the fermentation broth. The recovery of the high-boiling BDO from an aqueous fermentation broth presents the subsequent challenge. Here we propose a method for BDO isolation based on a reversible complexation with phenylboronate into an anionic complex. BDO can be recovered by back-extraction into an acidic solution. The composition of the extracted species was determined by NMR, MS, and GC-MS methods. The conditions of extraction and back-extraction were optimized using commercial BDO and finally applied to different fermentation broths. Up to 72-93% BDO can be extracted and up to 80-90% can be back-extracted under the optimized conditions. Purified bio-BDO was used in the presence of sulphuric acid for synthesis of methyl ethyl ketone (MEK), an established organic solvent and discussed tailor-made biofuel.
      PubDate: 2017-06-26T05:17:38.079088-05:
      DOI: 10.1002/cssc.201700899
  • Low-cost Perovskite Solar Cells Employing
           Dimethoxydiphenylamine-Substituted Bistricyclic Aromatic Enes as Hole
           Transporting Materials
    • Authors: Mohammad Khaja Nazeeruddin; Kasparas Rakstys, Sanghyun Paek, Giulia Grancini, Peng Gao, Vygintas Jankauskas, Abdullah M. Asiri
      Abstract: The synthesis, characterization and photovoltaic performance of series of novel molecular hole transporting materials (HTMs) based on bistricyclic aromatic enes (BAEs) are presented. The new derivatives have been obtained following the simple and straightforward two-step procedure from inexpensive starting reagents mimicking the synthetically challenging 9,9'-spirobifluorene moiety of the well-studied spiro-OMeTAD. The novel HTMs are tested in mixed caions and anions perovskite solar cells (PSCs) yielding power conversion efficiency (PCE) of 19.2% under standard global 100 mW cm−2 AM 1.5G illumination using 9-(2,7-bis(bis(4-methoxyphenyl)amino)-9H-fluoren-9-ylidene)-N2,N2,N7,N7-tetrakis(4-methoxyphenyl)-9H-thioxanthene-2,7-diamine (coded as KR374). The power conversion efficiency data confirms the easily attainable heteromerous fluorenylidenethioxanthene structure as valuable core for low-cost and highly efficient HTM design and paves the way towards cost-effective PSC technology.
      PubDate: 2017-06-26T04:17:33.543787-05:
      DOI: 10.1002/cssc.201700974
  • Mechanism of Microwave-assisted Pyrolysis of Glucose to Furfural Revealed
           by Isotopic Tracer and Quantum Chemical Calculations
    • Authors: Liwei Bao; Lei Shi, Hu Luo, Lingzhao Kong, Shenggang Li, Wei Wei, Yuhan Sun
      Abstract: Glucose labelled with 13C or 18O was used to investigate the mechanism during its conversion into furfural by microwave-assisted pyrolysis. The isotopic content and location in furfural were determined from GC/MS and 13C NMR measurements and data analysis. Our results suggest that the carbon skeleton in furfural is mainly derived from the C-1 to C-5 of glucose. The C of the aldehyde group and the O of the furan ring in furfural are primarily originated from the C-1 and O-5 of glucose, respectively. For the first time, the source of the O of the furan ring in furfural was elucidated directly by experiments, which is consistent with predictions from recent quantum chemical calculations. Furthermore, our own theoretical calculations yield substantially lower energy barriers than the previous predictions by considering the potential catalytic effect of formic acid, which is one of the pyrolysis products. The catalytic role of formic acid is further confirmed by our experimental evidence.
      PubDate: 2017-06-25T22:17:36.59933-05:0
      DOI: 10.1002/cssc.201700621
  • Enhancing perovskite electrocatalysis of solid oxide cells through
           controlled growth of nanoparticles
    • Authors: Bin Hua; Meng Li, Yi-Fei Sun, Jian-Hui Li, Jing-Li Luo
      Abstract: Perovskite oxides have received a great deal of attentions as promising electrodes in both solid oxide fuel cells (SOFCs) and solid oxide electrolyzer cells (SOECs) because of their reasonable reactivity, impurity tolerance, tunable property, etc. Particular explorations are still required for advancing the perovskite electrodes, which normally suffer from slow kinetics in electrocatalysis. In the past decades, several experimental studies have developed new classes of perovskites with advanced characteristics and electrode kinetics at technical levels. In parallel with those developments, the achievements in theoretical and computational studies have led to substantial understanding, at the atomic level, of their physicochemical properties and electrocatalytic behaviors. The chemical and structural flexibilities enable the perovskites to accommodate most metallic elements without destroying their complex matrix structures, thereby delivering a pathway to engineering their catalytic properties. In this contribution, we briefly introduce the recent advances in perovskite electrodes, and focus on the perovskites with exsolved nanoparticles as the enhanced electrocatalytic materials.
      PubDate: 2017-06-24T01:47:27.982784-05:
      DOI: 10.1002/cssc.201700936
  • Evaluating Dihydroazulene-Vinylheptafulvene Photoswitches for Solar Energy
           Storage Applications
    • Authors: Zhihang Wang; Jonas Udmark, Karl Börjesson, Rita Rodrigues, Anna Roffey, Maria Abrahamsson, Mogens B Nielsen, Kasper Moth-Poulsen
      Abstract: Efficient solar energy storage is a key challenge in striving towards a sustainable future. For this reason, molecules capable of solar energy storage and release through valence isomerization, so-called Molecular Solar Thermal energy storage (MOST), have been investigated. Here, we evaluate the energy storage potential through the photoconversion of the dihydroazulene-vinylheptafulvene (DHA/VHF) photo-thermal couple. The robust nature of this system has been determined through multiple energy storage and release cycles at elevated temperatures in three different solvents. In a non-polar solvent such as toluene, the DHA/VHF system can be cycled more than 70 times with less than 0.01% degradation per cycle. Moreover, the [Cu(CH3CN)4]PF6 catalyzed conversion of VHF to DHA was demonstrated in a flow reactor. The performance of the DHA/VHF couple was also evaluated in prototype photoconversion devices, both in the laboratory using a flow chip under simulated sunlight, and under outdoor conditions by using a parabolic mirror. Device experiments demonstrated a solar energy storage efficiency up to 0.13% in the chip device and up to 0.02% in the parabolic collector, respectively. Avenues for future improvements and optimization of the system are discussed herein.
      PubDate: 2017-06-23T10:45:24.556749-05:
      DOI: 10.1002/cssc.201700679
  • Quantitative insights into the Fast Pyrolysis of Extracted Cellulose,
           Hemicelluloses and Lignin
    • Authors: Marion Carrier; Michael Windt, Bernhard Ziegler, Jörn Appelt, Bodo Saake, Dietrich Meier, Anthony Bridgwater
      Abstract: The transformation of lignocellulosic biomass into bio-based commodity chemicals is technically possible. Among thermochemical processes, fast pyrolysis, a relatively mature technology that has now reached the commercial level, produces a high yield of an organic-rich liquid stream. Despite the recent efforts in elucidating the degradation paths of biomass pyrolysis, the selectivity and recovery rates of bio-compounds remain low. In an attempt to clarify the general degradation scheme of biomass fast pyrolysis and provide a quantitative insight, this study has combined the use of fast pyrolysis micro-reactors, spectrometric techniques and mixtures of unlabelled and Carbon-13 enriched materials. The first stage of the work reported aimed at selecting the type of reactor to ensure control of the pyrolysis regime. The comparison of chemical fragmentation patterns of 'primary' fast pyrolysis volatiles detectable by GC-MS between two small scale micro-reactors has shown the inevitable presence of secondary reactions. In a second stage, liquid fractions also made of 'primary' fast pyrolysis condensables have been analysed by quantitative liquid-state 13C-NMR providing a quantitative distribution of functional groups. The compilation of those results into a map that displays the distribution of functional groups according to the individual and main constituents of biomass confirmed the origin of individual chemicals within fast pyrolysis liquids.
      PubDate: 2017-06-23T07:51:02.255897-05:
      DOI: 10.1002/cssc.201700984
  • Hydroxyacetone: A glycerol based platform for electrocatalytic
           hydrogenation and hydrodeoxygenation processes
    • Authors: Waldemar Sauter; Olaf Lennart Bergmann, Uwe Schröder
      Abstract: Here we propose the use of hydroxyacetone, a dehydration product of glycerol, as a platform for the electrocatalytic synthesis of acetone, 1,2-propanediol and 2-propanol. 11 non-noble metals were investigated as electrode materials in combination with three different electrolyte compositions towards the selectivity, Coulomb efficiency (CE) and reaction rates of the electrocatalytic hydrogenation (formation of 1,2-propanediol) and hydrodeoxygenation (formation of acetone and propanol) of hydroxyacetone. With a selectivity of 84.5%, a reaction rate of 782 mmol/h*m2 and a CE of 32% (for 0.09 M hydroxyacetone), iron electrodes, in a chloride electrolyte, yielded the best 1,2 propanediol formation. A further enhancement of the performance can be achieved upon increasing the educt concentration to 0.5 M, yielding a reaction rate of 2248.1 mmol/ h*m² and a CE of 64.5%. Acetone formation was optimal at copper and lead electrodes in chloride solution, with lead showing the lowest tendency of side product formation. 2-propanol formation can be achieved using a consecutive oxidation of the formed acetone (at iron electrodes). 1-propanol formation was observed only in traces.
      PubDate: 2017-06-23T05:50:37.411707-05:
      DOI: 10.1002/cssc.201700996
  • Comprehensive insights into the thermal stability, biodegradability and
           combustion chemistry of Pyrrolidinium-based Ionic Liquids
    • Authors: Gebrekidan Gebreselassie Eshetu; Sangsik Jeong, Pascal Pandard, Amandine Lecocq, Guy Marlair, Stefano Passerini
      Abstract: The use of ionic liquids (ILs) as advanced electrolytes components in electrochemical energy storage devices is one of the most appealing and emerging options. However, though ILs are hailed as safer and eco-friendly electrolytes, overcoming the limitations imposed by the highly volatile/combustible carbonate based electrolytes, the full scale and precise appraisal of their overall safety levels under abuse conditions still need to be fully addressed. With the aim of providing the entreated level of information on the thermal and chemical stabilities as well as actual fire hazards, we embarked on a detailed investigation of the short - and long - term thermal stabilities, bio-degradability and combustion behaviour of various pyrrolidinium ([Pyr1A] +)-based ILs, enlisting different alkyl chain lengths, [Pyr1A] + (A=3-10), counter-anions ([TFSI]-/[FSI]-/[BETI]-), cations (Pyr14+/Pyr12O1+) and the effect of doping with Li salts (e.g. Li[TFSI]/[Pyr14] [TFSI]).
      PubDate: 2017-06-23T05:50:33.235195-05:
      DOI: 10.1002/cssc.201701006
  • Design of Iron(II) Pthalocyanine (FePc) Derived Oxygen Reduction
           Electrocatalysts for High Power Density Microbial Fuel Cells
    • Authors: Carlo Santoro; Rohan Gokhale, Barbara Mecheri, Alessandra D'Epifanio, Silvia Licoccia, Alexey Serov, Kateryna Artyushkova, Plamen Atanassov
      Abstract: Iron(II) Phthalocyanine (FePc) deposited onto two different carbonaceous supports was synthesized by the non-conventional pyrolysis-free method, studied in the reaction of oxygen reduction (ORR) in neutral media, incorporated in an air-breathing cathode structure and tested in operating microbial fuel cell (MFC) configuration. Rotating ring disk electrode (RRDE) analysis revealed high performances of the Fe-based catalysts compared with activated carbon (AC). It was shown that Black Pearls supported FePc (Fe-BP(N)) exhibits the highest performance in term of more positive onset, positive shift of half-wave potential and higher limiting as well as highest power density in operating MFC (243±7 μWcm-2) that was 33% higher than Fe-CNT(N) (182±5 μWcm-2). Power density generated by Fe-BP(N) was 92% higher than AC indicating that the utilization of PGM-free catalysts can boost up significantly the performances of MFCs.
      PubDate: 2017-06-23T04:05:35.994542-05:
      DOI: 10.1002/cssc.201700851
  • Molecular Self-Assembly Fabrication and Carrier Dynamics of Stable and
           Efficient CH3NH3Pb(1−x)SnxI3 Perovskite Solar Cells
    • Authors: Jiandong Fan; Chong Liu, Hongliang Li, Cuilin Zhang, Wenze Li, Yaohua Mai
      Abstract: The Sn-based perovskite solar cells (PSCs) provide the possibility that swaps the Pb element toward toxic-free PSCs. Here, we innovatively employed a molecular self-assembly approach to obtain a series CH3NH3Pb(1−x)SnxI3 (0≤x≤1) perovskite thin films with full coverage. The optimized planar CH3NH3Pb0.75Sn0.25I3 PSCs with inverted structure was consequently realized with a maximum power conversion efficiency (PCE) over 14 %, which displayed a stabilized power output (SPO) over 12 % within 200 s at 0.6 V forward bias. Afterward, we investigated the factors that limited the efficiency improvement of hybrid Sn-Pb PSCs, and analyzed the possible reason of the hysteresis effect occurred even in the inverted structure cell. Particularly, the oxidation of hybrid Sn-Pb perovskite thin film was demonstrated to be the main reason that caused the decreasing of minority-carrier lifetime, which quenched the carrier collection efficiency while the depletion layer was widened. The imbalance of charge transport was intensified that was associated with the increased hole defect-state density and decreased the electron defect-state density after Sn was introduced. This study is benefit to tackle the intractable issue regarding the toxic Pb in perovskite devices and step forward toward realizing the lead-free PSCs with high stability and efficiency.
      PubDate: 2017-06-22T20:51:01.167451-05:
      DOI: 10.1002/cssc.201700880
  • Nanoelectrical and Nanoelectrochemical Imaging of Pt/p-Si and Pt/p+-Si
    • Authors: Jingjing Jiang; Zhuangqun Huang, Chengxiang Xiang, Rakesh Poddar, Hans-Joachim Lewerenz, Kimberly M. Papadantonakis, Nathan Lewis, Bruce Brunschwig
      Abstract: The interfacial properties of electrolessly deposited Pt nanoparticles (Pt-NP) on p-Si and p+-Si electrodes have been resolved on the nanometer scale using a combination of scanning probe methods. Atomic-force microscopy (AFM) showed highly dispersed Pt nanoparticles. Conductive AFM measurements showed that only about half of the particles exhibited measurable contact currents, with a factor of 10^3 difference in current. Local current-voltage measurements revealed a rectifying junction with a resistance of ≥ 10 MΩ at the Pt-NP/p-Si interface, while Pt-NP/p+-Si samples formed an Ohmic junction with a local resistance of ≥ 1 MΩ. The particles were strongly attached to the sample surface in air. However in contact with an electrolyte, the adhesion of the particles to the surface was substantially lower. Scanning electrochemical microscopy (SECM) showed smaller, but more uniform electrochemical currents for the particles relative to the currents observed in conductive AFM measurements. In accord with the conductive AFM measurements, SECM measurements showed conductance through the substrate for only a minority of the particles. These results suggest that the electrochemical performance of the electrolessly deposited Pt nanoparticles on Si is ascribable to: 1) the high resistance of the contact between the particles and the substrate; 2) the low (
      PubDate: 2017-06-21T12:45:47.696481-05:
      DOI: 10.1002/cssc.201700893
  • Direct Electro-oxidation of Dimethyl Ether on Pt-Cu NanoChains
    • Authors: Bar Gavriel; Ronit Sharabi, Lior Elbaz
      Abstract: In this work, new catalyst for the direct electro-oxidation of dimethyl ether (DME) was synthesized and studied using an array of techniques. One of the most prominent catalysts for this reaction, platinum copper alloy (PtCu), was synthesized in an easy and low cost approach. Structural characterizations such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and elemental analysis revealed that the synthesized PtCu nanoparticles (3 nm on average), formed homogeneous NanoChains without aggregation of metallic platinum or copper. The catalyst's activity towards electro-oxidation of DME was tested using cyclic - voltammetry (CV) and in membrane-electrode assembly (MEA) in a full cell. The catalyst performance was found to be promising. Direct DME fuel cell (DDMEFC) studied in this work has relatively high energy density, of 13.5 mW cm-1 and thus shows great potential as fuel for low power fuel cells. The electrocatalysis of the DME oxidation reaction (DOR) was compared between synthesized PtCu and commercial PtRu/C and exhibited almost double the performance with the newly synthesized catalyst.
      PubDate: 2017-06-18T21:22:08.766903-05:
      DOI: 10.1002/cssc.201700702
  • Co-based Active Species Molecularly Immobilized on Carbon Nanotubes for
           Oxygen Reduction Reaction
    • Authors: Sujin Kim; Dawoon Jang, Joonwon Lim, Junghoon Oh, Sang Ouk Kim, Sungjin Park
      Abstract: Hybrid systems that molecule-based active species are combined with nanoscale materials may offer valuable routes to enhance the catalytic performances for electrocatalytic reactions. Development of rationally designed, cost-effective efficient catalysts for oxygen reduction reaction (ORR) is a crucial challenge for fuel cell and metal-air battery applications. In this work, we report a novel hybrid ORR catalyst material synthesized by a well-defined reaction pathway between Co-based organometallic molecules and N-doped multiwalled carbon nanotubes (MWCNT) at room temperature. The hybrid ORR catalyst shows excellent catalytic performances with an onset potential of 0.95 V (vs. RHE), superior durability and good methanol tolerance. Chemical and structural characterizations reveal that Co-based organometallic molecules maintained the original structure of Co(acetylacetonate)2 after prolonged cycles of reaction, while coordinated to heteroatoms of MWCNT. Thorough electrochemical investigation suggests that the major catalytic active site is Co-O4-NCNT.
      PubDate: 2017-06-18T21:21:58.068842-05:
      DOI: 10.1002/cssc.201701038
  • Sustainable separations of C4 hydrocarbons using microporous materials
    • Authors: Stefania Tanase-Grecea; Mascha Gehre, Zhiyong Guo, Gadi Rothenberg
      Abstract: Petrochemical refineries must separate hydrocarbons mixtures on a large scale for the production of fuels and chemicals. Most often, these hydrocarbons are separated by distillation, which is extremely energy-intensive. This high energy cost can be mitigated by developing materials that can enable efficient adsorptive separation. In this critical review, we first outline the principles of adsorptive separation. We then examine the case for C4 separations using zeolites and metal-organic frameworks (MOFs). By analysing both experimental and theoretical studies, we outline the challenges and opportunities in C4 separation, with a focus on the separation mechanisms and structure-selectivity correlations. Zeolites are commonly used as adsorbents, and in some cases can separate C4 mixtures well. The pore sizes of 8-membered-ring zeolites, for example, are in the order of the kinetic diameters of C4 isomers. Although zeolites have the advantage of a rigid and highly stable structure, this is often difficult to functionalize. MOFs are attractive candidates for hydrocarbon separation because their pores can be tailored to optimize the adsorbate-adsorbent interactions. MOF-5 and ZIF-7 show promising results in separating all C4 isomers, but breakthrough experiments under industrial conditions are needed to confirm these results. Moreover, the flexibility of the MOF structures could hamper their application under industrial conditions. All in all, adsorptive separation is a promising viable alternative, and it is likely to play an increasingly important role in tomorrow's refineries.
      PubDate: 2017-06-15T21:20:27.077112-05:
      DOI: 10.1002/cssc.201700657
  • Novel solid state lithium conductors for lithium metal batteries based on
           electrospun nanofibers and plastic crystal composites
    • Authors: Yundong Zhou; Xiaoen Wang, Haijin Zhu, Masahiro Yoshizawa-Fujita, Yukari Miyachi, Michel Armand, Maria Forsyth, George W. Greene, Jennifer M. Pringle, Patrick Howlett
      Abstract: Organic ionic plastic crystals (OIPCs) are a class of solid-state electrolyte with good thermal stability, non-flammability, non-volatility and good electrochemical stability. When prepared in a composite with electrospun polyvinylidene fluoride (PVdF) nanofibers, a 1:1 mixture of the OIPC N-ethyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide and LiFSI produced a free-standing, robust solid state electrolyte. These high concentration Li-containing electrolyte membranes had a transference number of 0.37 (± 0.02) and supported stable lithium symmetric-cell cycling at a current density of 0.13 mA cm-2. The effects of PVdF incorporation in the Li-containing plastic crystal were investigated for different ratios of PVdF and [Li][FSI]/[C2mpyr][FSI]. Li LiNi1/3Co1/3Mn1/3O2 cells were also prepared and cycled at ambient temperature and displayed good rate performance and stability.
      PubDate: 2017-06-15T03:20:22.086337-05:
      DOI: 10.1002/cssc.201700691
  • Self-assembled dendritic Pt nanostructure with high-index facets as highly
           active and durable electrocatalyst for oxygen reduction
    • Authors: Youngjin Jang; Kwang-Hyun Choi, Dong Young Chung, Ji Eun Lee, Namgee Jung, Yung-Eun Sung
      Abstract: The durability issues of Pt catalyst should be resolved for the commercialization of proton exchange membrane fuel cells. Nanocrystal structures with high-index facets have been recently focused to solve the critical durability problem of fuel cell catalysts since Pt catalysts with high-index facets can preserve the ordered surfaces without change of the original structures. However, it is very difficult to develop the effective and practical synthetic methods for Pt-based nanostructures with high-index facets. The current study describes a designed simple one-pot synthesis of self-assembled dendritic Pt nanostructures with electrochemically active and stable high-index facets. Pt nanodendrites exhibited 2 times higher ORR activity and superior durability (only 3.0 % activity loss after 10,000 potential cycles) than a commercial Pt/C. The enhanced catalytic performance was elucidated by the formation of well-organized dendritic structures with plenty of reactive interfaces among 5 nm-sized Pt particles and the co-existence of low- and high-index facets on the particles.
      PubDate: 2017-06-14T23:20:42.438481-05:
      DOI: 10.1002/cssc.201700852
  • Detection of Reactive Oxygen Species in AEM Fuel Cells using in situ
           Fluorescence Spectroscopy
    • Authors: Yunzhu Zhang; Javier Parrondo, Shrihari Sankarasubramanian, Vijay Ramani
      Abstract: The objectives of this study were: 1) to confirm superoxide anion radical (O₂·¯) formation, and 2) to monitor in real-time the rate of O₂·¯ generation in an operating anion exchange membrane (AEM) fuel cell using in situ fluorescence spectroscopy. 1,3-diphenlisobenzofuran (DPBF) was used as the fluorescent molecular probe due to its selectivity and sensitivity towards O₂·¯ in alkaline media. The activation energy for the in situ generation of O₂·¯ during AEM fuel cell operation was estimated to be 18.3 kJ mol-1. The rate of in situ generation of O₂·¯ correlated well with the experimentally measured loss in AEM ion-exchange capacity and ionic conductivity attributable to oxidative degradation.
      PubDate: 2017-06-14T23:20:22.58716-05:0
      DOI: 10.1002/cssc.201700760
  • Copper-Catalyzed Oxidative Dehydrogenative C(sp3)-H Bond Amination of
           (Cyclo)Alkanes using NH-Free Heterocycles as Amine Sources
    • Authors: Chang-Sheng Wang; Xiao-Feng Wu, Pierre H Dixneuf, Jean-Francois Soule
      Abstract: A copper-catalyzed oxidative C(sp3)-H/N-H coupling of NH-heterocycles with affordable (cyclo)alkanes was developed. This protocol involved C(sp3)-N bond formation via a radical pathway generated by a homolytic cleavage of di-tert-butyl peroxide and trapping of the radical(s) by copper catalysts. The reaction tolerated a series of functional groups, such as bromo, fluoro, ester, ketone, nitrile, methyl and methoxy. NH-free indoles, pyroles, pyrazoles, indazoles and benzotriazoles have been successfully N-alkylated.
      PubDate: 2017-06-14T04:20:26.762557-05:
      DOI: 10.1002/cssc.201700783
  • Enhanced Interfacial Charge Transfer on WO3 Photoanode by Molecular
           Iridium Catalyst
    • Authors: Haili Tong; Yi Jiang, Qian Zhang, Jialing Li, Wenchao Jiang, Donghui Zhang, Na Li, Lixin Xia
      Abstract: The rational design of active photoanodes for photoelectrochemical (PEC) water splitting is crucial for future applications in sustainable energy conversion. A combination of catalysts with photoelectrodes is generally required to improve surface kinetics and suppress surface recombination. In this study, we present an iridium complex (Ir-PO3H2) modified WO3 photoanode (WO3+Ir-PO3H2) for PEC water oxidation. When the Ir-based molecular catalyst (Ir-PO3H2) is anchored to a WO3 electrode, the photoanode shows a significant improvement both in photocurrent and faradaic efficiency compared to bare WO3. Under simulated sunlight illumination (AM 1.5G, 100 m Wcm−2) with an applied bias of 1.23 V vs. RHE, the photoanode exhibits a photocurrent of 1.16 mA cm−2 in acidic conditions, which is double that of bare WO3. The faradaic efficiency is promoted from 56% to 95%. Kinetic studies reveal that Ir-PO3H2 exhibits a different interfacial charge transfer mechanism on the WO3 photoanode for PEC water oxidation compared to iridium oxide (IrOx). Ir-PO3H2, as a water oxidation catalyst, can accelerate the surface charge transfer through rapid surface kinetics.
      PubDate: 2017-06-14T03:22:49.680737-05:
      DOI: 10.1002/cssc.201700721
  • Recent Advances in Bismuth Based Nanomaterials for Photoelectrochemical
           Water Splitting
    • Authors: Swhetha S M Bhat; Ho Won Jang
      Abstract: In recent years bismuth based nanomaterials are drawing considerable interest as potential candidates for photoelectrochemical (PEC) water splitting due to their narrow band gap, nontoxicity and low cost. The unique electronic structure with well dispersed valance band comprising of Bi 6s and O 2p orbital in the bismuth based materials offers suitable band gap to harvest visible light. This review presents the significant advancements in exploiting bismuth based materials for solar water splitting. An overview of different strategies employed and new ideas adopted to improve the PEC performance are discussed for these materials. Morphology control, construction of heterojunctions, doping and co-catalysts loading are the several approaches implemented to improve the efficiency of the solar water splitting. The key issues are identified and guidelines are suggested to rationalize the design of efficient bismuth based materials for sunlight driven water splitting.
      PubDate: 2017-06-13T22:20:49.128141-05:
      DOI: 10.1002/cssc.201700633
  • Stable Organic Radicals in Lignin; A Review
    • Authors: Dimitris Argyropoulos; Shradha S Patil
      Abstract: Lignin and the quest for the origin of stable organic radicals in it have seen numerous developments. Although there have been various speculations over the years on the formation of these stable radicals, researchers have not been to arrive at a solid, unequivocal hypothesis that applies to all treatments and types of lignin. The extreme complexity of lignin and its highly aromatic, crosslinked, branched and rigid structure has made such efforts rather cumbersome. Since the early fifties, researchers in this field have dedicated their efforts to establish methods for the detection and determination of spin content, theoretical simulations, and reactions on model compounds and spin trapping studies. While a significant amount of published research is available on lignin or its model compounds and the reactive intermediates involved during various chemical treatments (pulping, bleaching, extractions, chemical modifications, etc.) the literature provides a limited view on the origin, nature, and stability of such radicals. Consequently, this review is focused on examining the origin of such species in lignin, factors affecting their presence, reactions involved in their formation, and methods for their detection.
      PubDate: 2017-06-12T07:15:20.852255-05:
      DOI: 10.1002/cssc.201700869
  • Isohexide Dinitriles: a versatile family of renewable platform chemicals
    • Authors: Jing Wu; Shanmugam Thiyagarajan, Célia Fonseca Guerra, Pieter Eduard, Martin Lutz, Bart A. J. Noordover, Cor E. Koning, Daan S. van Es
      Abstract: New 2/5 1-carbon extended isohexide building blocks are now synthetically accessible by a convenient, selective base-catalyzed epimerization of the corresponding dinitriles. Kinetic experiments using the strong organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) show that all three possible isohexide dinitrile isomers are in a dynamic equilibrium. An epimerization mechanism is proposed, based on DFT calculations. Structural identification of all three possible isomers is based on NMR analysis as well as single crystal x-ray crystallography. DFT calculations confirmed that the observed crystal structures are indeed the lowest energy conformers of these isohexide derivatives.
      PubDate: 2017-06-07T05:20:38.270165-05:
      DOI: 10.1002/cssc.201700617
  • Greening the processes in MOFs synthesis and MOFs-involved sustainable
    • Authors: Junying Chen; Kui Shen, Yingwei Li
      Abstract: Given the shortage of sustainable resources and the arising serious environment impact in recent decades, the demand for clean technologies and sustainable sources is of great interest to worldwide researchers. As we look into the fields of energy saving and environment cleaning, the key point is the development of efficient catalysts, not only in the way of facile synthesis methods, but also the utilization of such catalysts in benign manners. This work reviews the dedication of metal-organic frameworks (MOFs) and MOF-based materials to these fields. The definition of MOFs and MOF-based materials will be primarily introduced followed by the brief description of the characterization and stability of MOF related materials under applied conditions. The greening processes of MOFs synthesis will be illustrated then, catalogued by benign solvents and conditions, and green precursors of MOFs. Further, the suitable application in sustainable catalysis will be summarized, focusing on several typical atom economic reactions, e.g., the direct introduction of H2 and O2, and C-C bond formation. The approaches towards reducing CO2 emitting by MOF-based catalysts will be described with special emphasis on CO2 fixation and CO2 reduction. In addition, driven by the explosive growth of energy consumption from last century, researches on biomass, which are renewable alternatives to fossil fuels and sustainable carbon feedstock for chemicals production, have been exploited. The advanced progress of biomass-related transformation will be illustrated. The fundamental insight into the nature of MOFs-based materials as constitutionally easily-recoverable heterogeneous catalysts and as supports to inducting varied active sites is thoroughly discussed. Finally, the facing challenges of the development in this field and the outlook for future research will be presented.
      PubDate: 2017-06-06T22:20:36.497952-05:
      DOI: 10.1002/cssc.201700748
  • Ionic Liquid-Assisted Microwave Synthesis of Solid Solutions of Perovskite
           Sr1-xBaxSnO3 for Photocatalytic Applications
    • Authors: Anja Verena Mudring; Tarek Alammar, Igor Slowing, Jim Anderegg
      Abstract: For the first time nanocrystal perovskite Sr1-xBaxSnO3 photocatalysts were prepared by means of microwave synthesis in an ionic liquid (IL) and subsequent heat-treatment. The influence of the Sr/Ba substitution on the structure, crystallization, morphology and, in the end, the photocatalytic efficiency of SrSnO3 was investigated. Based on the structure characterization using X-ray diffraction, with increasing Ba content in the lattice of SrSnO3 a symmetry increase from the orthorhombic perovskite structure for SrSnO3 to the cubic for BaSnO3 was observed. Analysis of the sample morphology using SEM reveals that the Sr1-xBaxSnO3 samples favor the formation of nanorods (500 nm - 5 μm in diameter and several micrometers in length). The band gap decreases with increasing Ba2+ content from 3.85 eV to 3.19 eV. Furthermore, the photocatalytic properties were evaluated by the hydroxylation of terephthalic acid (TA). The order of the activities of TA hydroxylation was Sr0.8Ba0.2SnO3> SrSnO3> BaSnO3> Sr0.6Ba0.4SnO3> Sr0.2Ba0.8SnO3. The highest photocatalytic activity was observed for Sr0.8Ba0.2SnO3 which can be attributed to the synergistic impacts of the modification of crystal structure and morphology, the relatively large surface area associated with the small crystallite size and suitable band gap size as well as band edge position.
      PubDate: 2017-06-06T22:20:33.920251-05:
      DOI: 10.1002/cssc.201700615
  • Boosting the supercapacitance of nitrogen-doped carbon by tuning surface
    • Authors: Jasper Biemolt; Ilse M. Denekamp, Thierry K. Slot, Gadi Rothenberg, David Eisenberg
      Abstract: We report that the specific capacitance of a highly porous, nitrogen-doped carbon is nearly tripled by orthogonal optimization of microstructure and surface chemistry. First, the carbons' hierarchical pore structure and specific surface area were tweaked by controlling the temperature and sequence of thermal treatments. The best process (pyrolysis at 900 °C, washing, and a second annealing at 1000 °C) yielded carbons with a specific capacitance of 117 F/g - nearly double that of a carbon made by a typical, single-step synthesis at 700 °C. Following the structural optimization, the surface chemistry of the carbons was enriched by applying an oxidation routine based on nitric and sulfuric acids in 1:4 ratio, at two different treatment temperatures (0 °C and 20 °C) and along different treatment times. The optimal treatment times are 4 h at 0 °C and only 1 h at 20 °C. Overall, specific capacitance nearly tripled relative to the original carbon, reaching to 168 F/g. The inherent nitrogen doping of the carbon comes into interplay with the acid-induced surface functionalization, creating a mixture of oxygen- and nitrogen-oxygen functionalities. The evolution of surface chemistry was carefully followed by X-ray photoelectron spectroscopy and by N2 sorption porometry, revealing stepwise surface functionalization and simultaneous carbon etching. Overall, these processes are responsible for the peak-shaped capacitance trends in the carbons.
      PubDate: 2017-06-06T10:15:21.602775-05:
      DOI: 10.1002/cssc.201700902
  • Mapping the free energy of lithium solvation in the protic ionic liquid
           Ethylammonuim Nitrate: A metadynamics study
    • Authors: Ali Kachmar; Marcelo Carignano, Teodoro Laino, Marcella Iannuzzi, Jürg Hutter
      Abstract: The understanding of lithium solvation and transport in ionic liquids is important due to the possible applications in electrochemical devices. Using first principles simulations aided with the metadynamics approach we study the free energy landscape for lithium at infinite dilution conditions in ethylammonium nitrate, a protic ionic liquid. We analyze the local structure of the liquid around the lithium cation and find a quantitative picture in agreement with experimental findings. Our simulations show that the lowest two free energy minima correspond to conformations with the lithium solvated either by 3 or 4 nitrates ions with a transition barrier between them of 0.2 eV. Other less probable conformations having a different solvation pattern are also investigated.
      PubDate: 2017-05-26T00:25:29.763862-05:
      DOI: 10.1002/cssc.201700510
  • Understanding the limiting factors of solvent annealed Small molecule bulk
           heterojunction organic solar cells from a chemical perspective
    • Authors: Aurelien Viterisi; Daniel Fernandez, Vijay Kumar Challuri, James william Ryan, Eugenia Martinez-Ferrero, Francesc Guispert-Guirado, Marta Martinez, Eduardo Escudero, Caterina Stenta, Lluis Francisco Marsal, Emilio Palomares
      Abstract: A detailed account on the limiting factors of solvent annealed bulk-heterojunction small molecule organic solars cell is given. This account is based on the extensive characterization of solar cell devices made from a library of five diketopyrolopyrole (DPP) donor dyes. Their chemical structure is designed in such a way as to provide insights on the energetics of solar cell active layer microstructure formation. Numerous chemical and physical properties of the active layers are assessed and interrelated such as light absorption, molecular packing in the solid state, crystal-forming properties in thin films, charge carrier mobility and charge carrier recombination kinetics. A myriad of characterization techniques are used such as UV-Vis absorption, photoluminescence, X-ray diffraction (XRD), AFM, photo-induced transient measurements which provide information on optical properties of the active layers, morphology and recombination kinetics. Consequently, a mechanism for the solvent vapour annealing-assisted formation of crystalline domains of donor molecules in the active layer is proposed, and the microstructure features are related to the J-V characteristics of the devices. According to this model, the crystalline phase in which the donor crystallize in the active layer is the key determinant in directing the formation of the microstructure.
      PubDate: 2017-05-24T10:20:27.604284-05:
      DOI: 10.1002/cssc.201700440
  • Electrochemically-driven fermentation of organic substrates with undefined
           mixed microbial cultures
    • Authors: Marianna Villano; Paola Paiano, Enza Palma, Alfredo Miccheli, Mauro Majone
      Abstract: Growing scientific interest in mixed microbial culture-based anaerobic biotechnologies for the production of value-added chemicals and fuels from waste organic residues requires a parallel focus on the development and implementation of strategies to control products distribution. This study examined the feasibility of an electro-fermentation approach, based on the introduction of a polarized (-700 mV vs. the standard hydrogen electrode) graphite electrode in the fermentation medium, to steer products distribution during the conversion of organic substrates (glucose, ethanol, and acetate supplied as single compounds or in mixtures) by undefined mixed microbial cultures. As a main result, in batch experiments the polarized electrode triggered a nearly 20-fold increase (relative to open circuit controls) in the yield of i-butyrate production (0.43±0.01 vs. 0.02±0.02 mol/ mol glucose) during the anaerobic fermentation of the ternary mixture of substrates, without adversely affecting the rate of substrate bioconversion. The observed change in the fermentative metabolism was most likely triggered by the (potentiostatic) regulation of the oxidation-reduction potential of the reaction medium rather than by the electrode serving as an electron donor.
      PubDate: 2017-05-04T07:15:37.59715-05:0
      DOI: 10.1002/cssc.201700360
  • Inside Back Cover: Detection of Reactive Oxygen Species in Anion Exchange
           Membrane Fuel Cells using In Situ Fluorescence Spectroscopy (ChemSusChem
    • Authors: Yunzhu Zhang; Javier Parrondo, Shrihari Sankarasubramanian, Vijay Ramani
      Pages: 3161 - 3161
      Abstract: The Inside Back Cover picture shows the sun made of a fluorescent dye molecule (1,3-diphenylisobenzofuran) shedding light on the interaction between the reactive oxygen species and the membrane molecular tree with the polymer chain branches on the left-hand side. All of this is happening inside individual cells in a fuel cell stack, which itself propels the car of tomorrow. And thus, we speed along the road to a bright, clean and green future. More details can be found in the Full Paper by Zhang et al. on page 3056 in Issue 15, 2017 (
      DOI : 10.1002/cssc.201700760).
      PubDate: 2017-08-10T01:53:41.740508-05:
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