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ENGINEERING (1209 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 7)
3D Research     Hybrid Journal   (Followers: 19)
AAPG Bulletin     Hybrid Journal   (Followers: 7)
AASRI Procedia     Open Access   (Followers: 15)
Abstract and Applied Analysis     Open Access   (Followers: 3)
Aceh International Journal of Science and Technology     Open Access   (Followers: 2)
ACS Nano     Full-text available via subscription   (Followers: 252)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 2)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Active and Passive Electronic Components     Open Access   (Followers: 7)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 6)
Advanced Science     Open Access   (Followers: 5)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 9)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 7)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17)
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 Engineering Software     Hybrid Journal   (Followers: 26)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 16)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 11)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 22)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 26)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 30)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in OptoElectronics     Open Access   (Followers: 5)
Advances in Physics Theories and Applications     Open Access   (Followers: 12)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 40)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aerobiologia     Hybrid Journal   (Followers: 2)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 5)
AIChE Journal     Hybrid Journal   (Followers: 32)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access   (Followers: 1)
Alexandria Engineering Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 28)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 11)
American Journal of Engineering Education     Open Access   (Followers: 9)
American Journal of Environmental Engineering     Open Access   (Followers: 17)
American Journal of Industrial and Business Management     Open Access   (Followers: 23)
Analele Universitatii Ovidius Constanta - Seria Chimie     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Regional Science     Hybrid Journal   (Followers: 8)
Annals of Science     Hybrid Journal   (Followers: 7)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 18)
Applied Clay Science     Hybrid Journal   (Followers: 5)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 4)
Applied Nanoscience     Open Access   (Followers: 8)
Applied Network Science     Open Access   (Followers: 1)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 3)
Applied Sciences     Open Access   (Followers: 2)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 5)
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 7)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
Asia-Pacific Journal of Science and Technology     Open Access  
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 1)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 8)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Current Engineering & Maths     Open Access  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 9)
Avances en Ciencias e Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 5)
Batteries     Open Access   (Followers: 6)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 23)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Motor Trade Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 2)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Survey of Business Conditions in Manufacturing : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Retail : An Executive Summary     Full-text available via subscription   (Followers: 4)
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Biofuels Engineering     Open Access   (Followers: 1)
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 10)
Biomedical Engineering     Hybrid Journal   (Followers: 15)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 14)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 18)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 34)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 9)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 2)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription   (Followers: 1)
Boundary Value Problems     Open Access   (Followers: 1)
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 14)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 14)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers, Droit, Sciences et Technologies     Open Access  
Calphad     Hybrid Journal  
Canadian Geotechnical Journal     Hybrid Journal   (Followers: 30)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 44)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 8)
Case Studies in Thermal Engineering     Open Access   (Followers: 4)
Catalysis Communications     Hybrid Journal   (Followers: 6)
Catalysis Letters     Hybrid Journal   (Followers: 2)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 7)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 7)
CEAS Space Journal     Hybrid Journal   (Followers: 1)
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 3)
Central European Journal of Engineering     Hybrid Journal   (Followers: 1)
CFD Letters     Open Access   (Followers: 6)
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 2)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Science Bulletin     Open Access   (Followers: 1)
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencias Holguin     Open Access   (Followers: 1)
CienciaUAT     Open Access  
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Full-text available via subscription   (Followers: 11)
CIRP Journal of Manufacturing Science and Technology     Full-text available via subscription   (Followers: 14)
City, Culture and Society     Hybrid Journal   (Followers: 24)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Coal Science and Technology     Full-text available via subscription   (Followers: 3)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 5)
Coatings     Open Access   (Followers: 4)
Cogent Engineering     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Color Research & Application     Hybrid Journal   (Followers: 1)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 14)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 13)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 27)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 270)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 195)
Composites Part B : Engineering     Hybrid Journal   (Followers: 276)
Composites Science and Technology     Hybrid Journal   (Followers: 191)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 15)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 8)
Computer Science and Engineering     Open Access   (Followers: 19)
Computers & Geosciences     Hybrid Journal   (Followers: 29)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 6)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 4)
Computers and Geotechnics     Hybrid Journal   (Followers: 11)
Computing and Visualization in Science     Hybrid Journal   (Followers: 6)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 32)
Conciencia Tecnologica     Open Access  
Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 7)
Control and Dynamic Systems     Full-text available via subscription   (Followers: 9)
Control Engineering Practice     Hybrid Journal   (Followers: 43)
Control Theory and Informatics     Open Access   (Followers: 8)
Corrosion Science     Hybrid Journal   (Followers: 25)
Corrosion Series     Full-text available via subscription   (Followers: 6)
CT&F Ciencia, Tecnologia y Futuro     Open Access   (Followers: 1)

        1 2 3 4 5 6 7 | Last

Journal Cover Applied Catalysis B: Environmental
  [SJR: 2.322]   [H-I: 158]   [18 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0926-3373
   Published by Elsevier Homepage  [3118 journals]
  • Porous defect-modified graphitic carbon nitride via a facile one-step
           approach with significantly enhanced photocatalytic hydrogen evolution
           under visible light irradiation
    • Authors: Di Zhang; Yongle Guo; Zhongkui Zhao
      Pages: 1 - 9
      Abstract: Publication date: 15 June 2018
      Source:Applied Catalysis B: Environmental, Volume 226
      Author(s): Di Zhang, Yongle Guo, Zhongkui Zhao
      Graphitic carbon nitride (g-C3N4) has been considered as one of the most promising photocatalysts for solar energy conversion. However, the intrinsic drawbacks of insufficient visible-light absorption and poor charge separation efficiency seriously limit its practical applications in visible light photocatalytic hydrogen evolution. In this work, a facile one-step strategy was proposed to construct a novel porous defect-modified graphitic carbon nitride (P-DCN) via thermal polymerization of a freeze-dried crystalline mixture containing dicyandiamide (DCDA) and ammonium chloride (NH4Cl) under nitrogen atmosphere, in which both porous feature and two types of defects (cyano group and nitrogen vacancy) were simultaneously introduced into g-C3N4 framework. Results show that the as-synthesized P-DCN Exhibits 26 times higher hydrogen evolution rate (HER) under visible light irradiation than bulk g-C3N4, reaching 20.9 μmol h−1. In combination of porous and defective characteristics, P-DCN even demonstrates 2.0 and 1.8 folds higher HER than highly active porous graphitic carbon nitride (P-CN) and defect-modified g-C3N4 (DCN), respectively. The outstanding photocatalytic performance for hydrogen production originates from the remarkably improved visible light harvesting capability, the notably promoted separation and recombination inhibition of photoinduced charge carriers, and the increased amount of active sites and the strengthened mass transfer resulting from the combination effect of the porous feature, as-formed defects, and the enlarged specific surface area. Moreover, this approach could render a new insight for designing highly efficient visible light photocatalysts for the other transformations including CO2 reduction, environmental remediation, and organic synthesis process.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.044
      Issue No: Vol. 226 (2017)
  • Continual injection of photoinduced electrons stabilizing surface plasmon
           resonance of non-elemental-metal plasmonic photocatalyst CdS/WO3−x for
           efficient hydrogen generation
    • Authors: Zaizhu Lou; Mingshan Zhu; Xianguang Yang; Yao Zhang; Myung-Hwan Whangbo; Baojun Li; Baibiao Huang
      Pages: 10 - 15
      Abstract: Publication date: 15 June 2018
      Source:Applied Catalysis B: Environmental, Volume 226
      Author(s): Zaizhu Lou, Mingshan Zhu, Xianguang Yang, Yao Zhang, Myung-Hwan Whangbo, Baojun Li, Baibiao Huang
      To remedy the instability problem of the non-elemental-metal (NEM) plasmonic photocatalyst WO3−x in aqueous solution, a novel strategy of photoinduced electron injection was applied to construct CdS/WO3−x hetereostructures by growing WO3−x on semiconductor CdS nanowires. Under visible/near-infrared light irradiation, the NEM plasmonic CdS/WO3−x nanowires are highly stable and exhibit a much higher activity (1.60 mmol g−1 h−1) than do plasmonic WO3−x (negligible amount) and semiconductor CdS (0.53 mmol g−1 h−1) in hydrogen generation. Wavelength dependent photocatalytic performance and Single-particle PL study demonstrate that photo-excited electrons on CdS continually inject into conduction band of WO3−x, so that the surface plasmon resonance (SPR) of the NEM plasmonic photocatalyst WO3−x is sustained while hot electrons generated by the SPR excitation are consumed for hydrogen generation.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.023
      Issue No: Vol. 226 (2017)
  • Hybridization of graphene oxide with commercial graphene for constructing
           3D metal-free aerogel with enhanced photocatalysis
    • Authors: Kang-Qiang Lu; Lan Yuan; Xin Xin; Yi-Jun Xu
      Pages: 16 - 22
      Abstract: Publication date: 15 June 2018
      Source:Applied Catalysis B: Environmental, Volume 226
      Author(s): Kang-Qiang Lu, Lan Yuan, Xin Xin, Yi-Jun Xu
      The electrical conductivity and charge carrier mobility of reduced graphene oxide (RGO) based 3D aerogel using graphene oxide (GO) as precursor is often restricted by the intrinsic population of defects and thus disruption of 2D π-conjugation in the domain of RGO sheets. Here, we report a facile and efficient approach to improve the electrical conductivity of RGO aerogel by introducing highly conductive commercial Elicarb graphene (EGR). GO acting as a “macromolecular surfactant” can be used to simultaneously resolve the intrinsic drawback of low solution dispersibility of EGR and provides the basic skeleton for solution-processable synthesis of RGO@EGR-Eosin Y (RGO@EGR-EY) metal-free 3D aerogel composites. The as-synthesized RGO@EGR-EY aerogel with superior electrical conductivity facilitates more efficient separation and transfer of photogenerated charge carriers, and consequently exhibits much higher photocatalytic activity than RGO-EY aerogel. It is hoped that our current work could open promising prospects for the rational utilization of highly conductive commercial graphene to fabricate graphene-based aerogel for enhanced photoredox applications.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.032
      Issue No: Vol. 226 (2017)
  • Green assembly of stable and uniform silver nanoparticles on 2D silica
           nanosheets for catalytic reduction of 4-nitrophenol
    • Authors: Zhaoli Yan; Liangjie Fu; Xiaochao Zuo; Huaming Yang
      Pages: 23 - 30
      Abstract: Publication date: 15 June 2018
      Source:Applied Catalysis B: Environmental, Volume 226
      Author(s): Zhaoli Yan, Liangjie Fu, Xiaochao Zuo, Huaming Yang
      A facile, environment-friendly route is illustrated for the efficient assembly of stable and uniform silver nanoparticles (AgNPs) on the surface of two-dimensional (2D) silica nanosheets (SiNSs, derived from natural kaolinite mineral) via in-situ reduction using Sn(II) as reductant. Compared to the common reduction method using NaBH4 reductant, the loaded AgNPs on AgNPs/SiNSs nanocomposite showed higher purity, uniformity and stability (antioxygenation). The catalytic reduction of 4-nitrophenol (4-NP) over AgNPs/SiNSs nanocatalyst was almost complete within 40 s without stirring and the apparent kinetic rate constant k app (80.19 × 10−3 s−1) is much higher than those of other substrate-supported Ag/Au nanocatalysts. The effects of support material and assembly approach of AgNPs on the catalytic performance were discussed in detail. The high turnover frequency (TOF) for AgNPs/SiNSs nanocatalyst (3.52 min−1) indicates that the high-density dispersion of uniform small-sized AgNPs on 2D SiNSs surface is responsible for the excellent catalytic property, which offer many active sites for effective contact with the reactants and fast interfacial electron transfer from the AgNPs surface to 4-NP. It exhibits the great potential of 2D silica nanosheets as support materials for the efficient assembly of uniform noble-metal nanoparticles. Moreover, the 2D AgNPs/SiNSs nanocomposite holds a stable catalytic efficiency (around 100%) over five reaction cycles. The high efficiency and convenience have been demonstrated by purifying the 4-NP polluted water in the “filtering and catalyzing” device, in which the polluted water could become colorless within 10 s.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.040
      Issue No: Vol. 226 (2017)
  • Homogeneous Cu2O p-n junction photocathodes for solar water splitting
    • Authors: Tuo Wang; Yijia Wei; Xiaoxia Chang; Chengcheng Li; Ang Li; Shanshan Liu; Jijie Zhang; Jinlong Gong
      Pages: 31 - 37
      Abstract: Publication date: 15 June 2018
      Source:Applied Catalysis B: Environmental, Volume 226
      Author(s): Tuo Wang, Yijia Wei, Xiaoxia Chang, Chengcheng Li, Ang Li, Shanshan Liu, Jijie Zhang, Jinlong Gong
      Cu2O is considered as one of the most promising p-type semiconductors for photocathodes in solar water splitting due to its abundance, nontoxicity and appropriate band gap of 2.0 eV with favorable energy band positions. It has been long desired to find a proper n type semiconductor for p-Cu2O to form a p-n junction to generate a more positive onset potential. However, most previous research adopted heterogeneous p-n junctions due to the difficulty in obtaining n-type Cu2O, and the utilization of p-n Cu2O homojuncion was limited to solid-state photovoltaic devices. This paper describes a facile electrodeposition process for n-type Cu2O to construct the homogenous p-n junction, which is further protected by TiO2 for water splitting, demonstrating the possibility of applying Cu2O p-n homojunction in an aqueous condition for the first time. Compared with the heterogeneous Schottky junction counterpart, this p-n homojunction significantly increases the built-in potential for efficient charge separation, which leads to an anodic onset potential shift from 0.3 V to 0.7 V versus the reversible hydrogen electrode (RHE), reaching a photocurrent of 4.30 mA/cm2 at 0 V vs. RHE under AM1.5G. The performance of this electrodeposited p-n Cu2O photocathode without using the expensive Au back contact is comparable to the most efficient Cu2O photocathodes reported previously.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.022
      Issue No: Vol. 226 (2017)
  • Investigation of the active sites and optimum Pd/Al of Pd/ZSM–5 passive
           NO adsorbers for the cold-start application: Evidence of isolated-Pd
           species obtained after a high-temperature thermal treatment
    • Authors: Jaeha Lee; YoungSeok Ryou; Sung June Cho; Hyokyoung Lee; Chang Hwan Kim; Do Heui Kim
      Pages: 71 - 82
      Abstract: Publication date: 15 June 2018
      Source:Applied Catalysis B: Environmental, Volume 226
      Author(s): Jaeha Lee, YoungSeok Ryou, Sung June Cho, Hyokyoung Lee, Chang Hwan Kim, Do Heui Kim
      We investigated the chemisorptive NO adsorption ability at a low temperature (120 °C) of the Pd/ZSM–5 passive NOx adsorbers (PNA) to address the cold-start NOx emission. The Pd/ZSM–5 showed a much higher NO adsorption ability after the oxidative treatment at 750 °C compared with the 500 °C treatment; according to the combined EXAFS, XPS and XRD results, atomically dispersed Pd species were formed over the former, while small PdO agglomerates were observed over the latter. The Pd species on the Pd/ZSM–5 were further examined by applying a NH4NO3-titration method, where an ion exchange occurred with only the ionic Pd in the zeolite. When the Pd(2)/ZSM–5 was treated at 750 °C, it exchanged ions with an NH4NO3 solution whereby most of the Pd was ion-exchanged, and this resulted in a decreased NO adsorption capability. Alternatively, a much lesser amount of ion-exchanged Pd was found on the Pd/ZSM–5 that was treated at 500 °C. The combined results indicate that the ionic-Pd species on the ZSM–5, not the bulk PdO, are the active sites for the chemisorptive NO adsorption at the low temperature. The NO adsorption capability was also investigated as a function of the Pd loading and the Si-to-Al2 molar ratio of the ZSM–5. The results suggest that an optimum Pd-to-Al molar ratio exists for the Pd/ZSM–5 with the maximum NO adsorption capability, which was found at around 0.25, thereby suggesting that the Al in the ZSM–5 framework led to the high dispersion of the ionic-Pd species up to the optimum Pd/Al ratio. Above the optimum Pd/Al ratio, however, the bulk-PdO phase formed on the ZSM–5 resulting in a lower NO adsorption capability; that is, the ZSM–5 with the higher Al content required a higher Pd amount for the attainment of the optimum NO adsorption capability. In summary, the chemisorptive NO adsorption at the low temperature is significantly influenced by both the Si-to-Al2 molar ratio and the Pd-to-Al molar ratio of the Pd/ZSM–5 catalysts.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.031
      Issue No: Vol. 226 (2017)
  • An active nanoporous Ni(Fe) OER electrocatalyst via selective dissolution
           of Cd in alkaline media
    • Authors: Jun-Hyuk Kim; Duck Hyun Youn; Kenta Kawashima; Jie Lin; Hyungseob Lim; C. Buddie Mullins
      Pages: 1 - 7
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Jun-Hyuk Kim, Duck Hyun Youn, Kenta Kawashima, Jie Lin, Hyungseob Lim, C. Buddie Mullins
      Although there has been a significant progress regarding electrocatalysts for the electrochemical oxygen evolution reaction, further breakthroughs are still required due to its sluggish 4-electron transfer mechanism. Ni is considered as a potential candidate for the oxygen evolution reaction (OER) in alkaline media in lieu of noble metals, however, the utility of Ni has been limited by the required and relatively high overpotentials. In this study, we fabricated a nanoporous Ni structure by selective and partial dissolution of Cd from a NiCd composite (without using hazardous acids or bases). The formation of nanoporous Ni greatly enhanced OER performance because of the increased number of catalytic sites. Furthermore, there was a promotional electronic effect on the electrocatalyst induced by Cd atoms under the Ni surface tuning the catalytic reactivity could be tuned. Additionally, Fe deposition on the porous Ni-Cd structure significantly raised the OER activity via a reduction in the overpotential from a value of η=382mV (before Fe deposition) to η=290mV (after Fe deposition) to achieve 10mAcm−2.
      Graphical abstract image

      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.053
      Issue No: Vol. 225 (2017)
  • Highly efficient photocatalytic activity and mechanism of Yb3+/Tm3+
           codoped In2S3 from ultraviolet to near infrared light towards chromium
           (VI) reduction and rhodamine B oxydative degradation
    • Authors: Zhibin Wu; Xingzhong Yuan; Guangming Zeng; Longbo Jiang; Hua Zhong; Yingcong Xie; Hui Wang; Xiaohong Chen; Hou Wang
      Pages: 8 - 21
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Zhibin Wu, Xingzhong Yuan, Guangming Zeng, Longbo Jiang, Hua Zhong, Yingcong Xie, Hui Wang, Xiaohong Chen, Hou Wang
      The Yb3+/Tm3+ codoped flower−like tetragonal In2S3 photocatalysts were synthesized through a hydrothermal route, and the crystal phases, morphologies, chemical compositions and optical properties were characterized. The results shown that the doping with Yb3+/Tm3+ did not significantly change the crystallinity of In2S3, but induced the generation of intermediate energy states for efficient charge separation. The Yb3+/Tm3+ codoped In2S3 presented a significant enhancement of photoactivity towards chromium (VI) reduction and rhodamine B oxidation from UV to NIR light. The best photocatalytic synergism was obtained for the sample with the mole ratio of In3+:Yb3+:Tm3+ at 159:40:1, in which the chromium (VI) reduction efficiency was 97.9% (NIR, 100min), 99.3% (vis, 10min) and 98.3% (UV, 10min), while the rhodamine B degradation efficiency was 98.4% (NIR, 100min), 97.3% (vis, 14min), and 96.3% (UV, 14min). The favorable NIR photoactivity was mainly attributed to the upconversion mechanism via energy level transition of Yb3+/Tm3+. Under the full−spectra−light irradiation for 6min and 7min, the removal efficiency of chromium (VI) and rhodamine B could reach to 99.4% and 94.8%, the corresponding rate constant was 2.17 and 5.60 times of pure In2S3, respectively. The improved photocatalytic efficiency might be attributed to the enhanced light absorption and favorable charge separation resulted from the intermediate energy states and/or sulfur vacancies. In addition, the free radical capture and electron spin resonance experiments were also performed to determined the role of O2 − and h+ species during photocatalytic oxidation process.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.040
      Issue No: Vol. 225 (2017)
  • A novel route combined precursor-hydrothermal pretreatment with microwave
           heating for preparing holey g-C3N4 nanosheets with high crystalline
           quality and extended visible light absorption
    • Authors: Qiong Liu; Xueli Wang; Qian Yang; Zhengguo Zhang; Xiaoming Fang
      Pages: 22 - 29
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Qiong Liu, Xueli Wang, Qian Yang, Zhengguo Zhang, Xiaoming Fang
      The photocatalytic water splitting for hydrogen fuel by utilizing solar energy is considered a useful route to settle the energy crisis, but a bottleneck is occurred in developing a highly efficient photocatalysts. Herein, a facile method is applied to fabricate the holey carbon nitride (HCN) nanosheets with high crystallization network and extended optical absorption region by using the hydrothermal and microwave processes. The hydrothermal treatment of dicyandiamide will enable it to transform into the melamine-cyanaurate complex which would then form the ultrathin CN nanosheets with the abundant porous structure. And then the microwave-assisted thermolysis process helps the generation of g-C3N4 which retains the highly crystalline and the enhanced optical absorption region. Eventually, the highly crystalline network comes with the narrowed band gap and the higher specific surface area encounter in optimized g-C3N4 leading it exhibits a relatively high photocatalytic performance than pristine bulk carbon nitride which the hydrogen evolution rate of it reaching 81.6μmol/h.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.044
      Issue No: Vol. 225 (2017)
  • Bone char-derived metal-free N- and S-co-doped nanoporous carbon and its
           efficient electrocatalytic activity for hydrazine oxidation
    • Authors: André L. Cazetta; Tao Zhang; Taís L. Silva; Vitor C. Almeida; Tewodros Asefa
      Pages: 30 - 39
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): André L. Cazetta, Tao Zhang, Taís L. Silva, Vitor C. Almeida, Tewodros Asefa
      Bone char (BC) was successfully used, for the first time, both as a self-template/a pore-former and a precursor of heteroatoms (N and S atoms) during carbonization of sucrose, allowing for the synthesis of nanoporous N- and S-co-doped carbon (NSC) material possessing high surface area and excellent electrocatalytic activity. BC’s ability to help with the formation of nanopores in the carbon material was indirectly confirmed by making a control material, denoted as pyrolyzed sucrose or PS, under the same condition but without including BC in the reaction media. N2 gas porosimetry showed that NSC had a very large BET surface area (1108m2 g−1), which is about 60% higher than that of PS (443m2 g−1). Comparison of the SEM images of the two materials also indicated some differences in their textural and morphological features. XPS analysis showed that NSC had a higher content of S (2.29%) than PS (0.21%) and that the S atoms were distributed mostly in the form of thiophenic moieties (32.3% for the PS and 59.2% for the NSC). Although some of the S groups were originated from sulfuric acid, which was used for the dehydration of sucrose during the synthesis of the materials, this result indicated that BC was the major source of the S dopant atoms in NSC as well as the major reason for the formation of thiophenic groups in this material. Furthermore, while PS’s structure did not have N dopants, NSC’s lattice had about 1.39% of N dopant atoms that existed in the form of pyridinic, pyrrolic and graphitic groups and that were also originated from BC. X-ray diffraction and Raman spectroscopy revealed that NSC’s lattice had a higher density of defects than PS. Owing to its high surface area and optimal density of heteroatom dopant groups and defect sites, NSC exhibited excellent electrocatalytic activity toward the hydrazine oxidation reaction (HzOR), or the lowest overpotential ever reported for this reaction, along with a high current density. Besides making it among the most efficient electrocatalysts for HzOR, its electrocatalytic performance can make this metal-free material a good alternative to the conventional metal-based electrocatalysts that are commonly used in HzOR-based fuel cells.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.050
      Issue No: Vol. 225 (2017)
  • Constructing magnetic catalysts with in-situ solid-liquid interfacial
           photo-Fenton-like reaction over Ag3PO4@NiFe2O4 composites
    • Authors: Shuquan Huang; Yuanguo Xu; Ting Zhou; Meng Xie; Yun Ma; Qingqing Liu; Liquan Jing; Hui Xu; Huaming Li
      Pages: 40 - 50
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Shuquan Huang, Yuanguo Xu, Ting Zhou, Meng Xie, Yun Ma, Qingqing Liu, Liquan Jing, Hui Xu, Huaming Li
      A high-performance photocatalyst should be superior not only in light absorption and charge transfer but also surface catalytic reaction. Here we report a green and simple strategy for evenly decorating Ag3PO4 particles using magnetic NiFe2O4 nanoparticles (NPs). The NiFe2O4 NPs could act as a magnetic support material for recycling the photocatalysts, as well as in situ catalytically decompose the H2O2 produced on the surface of Ag3PO4 into O2 − and OH radicals via a photo-Fenton process. The catalytic decomposition of H2O2 could produce strong oxidative capacity O2 − and OH radicals for the organic pollutants degradation and reduce host semiconductor holes ( h + ( A g 3 P O 4 ) ) consumption by these produced H2O2. Thus, the photocatalytic activities of Ag3PO4@NiFe2O4 composites were greatly enhanced. Taking the photocatalytic degradation of Methyl orange (MO), hardly decomposed colorless phenol compounds bisphenol A (BPA) and killing Escherichia coli (E. coli) as mode photocatalytic reactions, this system exhibited superior photocatalytic performances than that of pristine Ag3PO4. Electron spin resonance (ESR) spectroscopy and sacrificial-reagent incorporated photocatalytic characterizations indicated that the in situ eliminating/active decomposition of H2O2 produced by Ag3PO4 was the main reason for the enhanced photocatalytic activities.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.045
      Issue No: Vol. 225 (2017)
  • Antimicrobial activity of photocatalysts: Fundamentals, mechanisms,
           kinetics and recent advances
    • Authors: Priyanka Ganguly; Ciara Byrne; Ailish Breen; Suresh C. Pillai
      Pages: 51 - 75
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Priyanka Ganguly, Ciara Byrne, Ailish Breen, Suresh C. Pillai
      Photocatalysis has recently been emerged as an effective green solution for antimicrobial disinfection applications. Photocatalytic disinfection has been observed to be efficient in deactivation of extensive varieties of organisms. Numerous gram positive and gram negative bacterial strains such as Escherichia coli, Staphylococcus aureus, Streptococcus pneumonia etc. have been studied. Similarly, fungal strains such as Aspergillus niger, Fusarium graminearum, algal (Tetraselmis suecica, Amphidinium carterae etc.) and viral strains have also been examined in the last decades. The present review sketches the photocatalytic mechanism and provides a brief account of several model organisms used for the disinfection studies. It presents an overview of the major kinetic models such as the Chick’s model, Chick-Watson model, delayed Chick- Watson model and Hom’s with modified Hom’s model. Furthermore, it summarises the importance of operational parameters on the inactivation kinetics and discusses the recent advances of the disinfection results by novel composites and progress in structural or morphological improvements in conventional catalyst. The current review presents a brief overview of the state of the art commercial products utilising photocatalytic antibacterial property. Finally, it details the major international testing standards (ISO, JIS, CEN and ASTM) for photocatalytic antimicrobial applications.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.018
      Issue No: Vol. 225 (2017)
  • Bread-making synthesis of hierarchically Co@C nanoarchitecture in
           heteroatom doped porous carbons for oxidative degradation of emerging
    • Authors: Wenjie Tian; Huayang Zhang; Zhao Qian; Tianhong Ouyang; Hongqi Sun; Jingyu Qin; Moses O. Tadé; Shaobin Wang
      Pages: 76 - 83
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Wenjie Tian, Huayang Zhang, Zhao Qian, Tianhong Ouyang, Hongqi Sun, Jingyu Qin, Moses O. Tadé, Shaobin Wang
      Employing low-cost and abundant wheat flour, sodium bicarbonate, cysteine and cobalt nitrate as precursors, we for the first time present a facile one-pot pyrolysis strategy for homogeneous assembly of core-shell Co@C nanoparticles with nitrogen and sulfur into hierarchically porous carbons (Co-N-S-PCs). The samples are highly efficient for oxidative decomposition of p-hydroxybenzoic acid (HBA) and phenol. It was found that Co@C nanoparticles are crucial for the generation of singlet oxygen in advanced oxidation processes (AOPs), which works together with hydroxyl and sulfate radicals in efficient decomposition of HBA. Density functional theory (DFT) calculations disclose that electron transfer from metal Co to C shells greatly improves the Fermi level and chemical activity of the C atoms. The combination of Co-C interaction with N, S codoping further bring in catalytic active sites in the graphitic shells where the charge states of C atoms are increased. This template-free strategy is scalable to prepare highly efficient catalysts, including functional carbon materials modified with non-precious metal species or pure and well-dispersed porous core-shell nanoparticles for environmental or energy applications.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.056
      Issue No: Vol. 225 (2017)
  • Hollow PdCu2@Pt core@shell nanoparticles with ordered intermetallic cores
           as efficient and durable oxygen reduction reaction electrocatalysts
    • Authors: Hee-Young Park; Jin Hoo Park; Pil Kim; Sung Jong Yoo
      Pages: 84 - 90
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Hee-Young Park, Jin Hoo Park, Pil Kim, Sung Jong Yoo
      Carbon-supported hollow PdCu2@Pt core@shell nanoparticles with ordered intermetallic cores were prepared as an efficient and durable oxygen reduction reaction (ORR) electrocatalyst for polymer electrolyte membrane fuel cells (PEMFCs). PdCu2 cores prepared using a chemical reduction method were thermally treated to produce ordered intermetallic structures. A Pt shell was then deposited via a galvanic displacement process. The effect of the galvanic displacement conditions on the properties and structure of the obtained core–shell nanoparticles was investigated by varying the solution pH and anion concentration. Acidic conditions and low Cl− concentrations were found to provide a uniform Pt layer with a hollow core, while maintaining the ordered intermetallic core structure. These hollow PdCu2@Pt core@shell nanoparticles showed high activity and stability for ORR electrocatalysis in PEMFCs.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.052
      Issue No: Vol. 225 (2017)
  • Heterogeneous activation of persulfate by reduced graphene
           oxide–elemental silver/magnetite nanohybrids for the oxidative
           degradation of pharmaceuticals and endocrine disrupting compounds in water
    • Authors: Chang Min Park; Jiyong Heo; Dengjun Wang; Chunming Su; Yeomin Yoon
      Pages: 91 - 99
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Chang Min Park, Jiyong Heo, Dengjun Wang, Chunming Su, Yeomin Yoon
      Reduced graphene oxide hybridized with zero-valent silver and magnetite nanoparticles (NPs) (rGO-Ag0/Fe3O4 nanohybrids) prepared via in situ nucleation and crystallization was used to activate peroxydisulfate (PDS) for degradation of pharmaceuticals and endocrine disrupting compounds (phenol, acetaminophen, ibuprofen, naproxen, bisphenol A, 17β-estradiol, and 17α-ethinyl estradiol). The deposition of Ag0 and Fe3O4 in rGO nanosheet enhanced the catalytic removal of phenol in the heterogeneous activation of PDS. The adsorption capacities of rGO-Ag0/Fe3O4 for 10μM phenol were 1.76, 1.33, and 2.04μmolg−1-adsorbent at pH 4, 7, and 10, respectively, which are much higher than those of single NPs studied (Ag0, nanoscale zero-valent iron, and rGO). The rGO-Ag0/Fe3O4 effectively activated PDS to produce strong oxidizing SO4 − and facilitate an electron transfer on the surface of the nanohybrid. The initial pseudo-first-order rate (k ini) constant for phenol degradation in PDS/rGO-Ag0/Fe3O4 system was 0.46h−1 at pH 7, which is approximately eight times higher than that in the presence of single NPs (k ini =0.04-0.06h−1) due to the synergistic effects between adsorption and catalytic oxidation. Among various organic contaminants tested, the simultaneous use of rGO-Ag0/Fe3O4 (0.1g/L) and PDS (1mM) achieved more than 99% degradation of acetaminophen and 17β-estradiol at pH 7. The radical scavenging studies with methanol and natural organic matter indicated that phenol was more likely to be degraded via free SO4 − and OH formation or a non-radical oxidative pathway. Our findings indicate that the rGO-Ag0/Fe3O4 nanohybrids can be used as an efficient magnetically-separable nanocatalyst for removal of organic compounds in water and wastewater treatment.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.058
      Issue No: Vol. 225 (2017)
  • Composite H3PW12O40–TiO2 catalysts for toluene selective
    • Authors: Guillermo R. Bertolini; Luis R. Pizzio; Anna Kubacka; Mario J. Muñoz-Batista; Marcos Fernández-García
      Pages: 100 - 109
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Guillermo R. Bertolini, Luis R. Pizzio, Anna Kubacka, Mario J. Muñoz-Batista, Marcos Fernández-García
      A series of composite systems based on titania and growing quantities of tungstophosphoric acid are prepared and characterized using infrared, nuclear resonance, UV–visible, photoluminescence, and photoelectron spectroscopies, transmission electron microscopy as well as x-ray diffraction and porosimetry techniques. These techniques showed evolution of the tungstophosphoric acid species supported into titania while this majority component of the system suffers minor changes. The activity and stability of the composite samples for gas phase toluene photo-oxidation under UV and sunlight-type irradiation conditions was measured by means of the reaction rate and the photonic efficiency parameter. The modeling of the radiation field was accomplished by numerically solving the radiative transfer equation. The photo-activity of the composite materials showed a significant selectivity towards the transformation of the hydrocarbon into a partially oxidized product, benzaldehyde. Both the activity and selectivity of the titania are significantly affected by the presence of tungstophosphoric acid species. The physico-chemical characterization was able to point out to the leading role of specific polytungstate species in driving the enhancement of the activity and selectivity of the reaction, rendering stable, highly active and selective photo-catalysis.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.055
      Issue No: Vol. 225 (2017)
  • Hydrothermal synthesis of NiCeOx nanosheets and its application to the
           total oxidation of propane
    • Authors: Zong Hu; Song Qiu; Yang You; Yun Guo; Yanglong Guo; Li Wang; Wangcheng Zhan; Guanzhong Lu
      Pages: 110 - 120
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Zong Hu, Song Qiu, Yang You, Yun Guo, Yanglong Guo, Li Wang, Wangcheng Zhan, Guanzhong Lu
      A series of NiCeOx mixed metal oxide catalysts with various Ce/(Ce+Ni) ratios were prepared using hydrothermal methods The NiCeOx catalyst with a 4% Ce/(Ni+Ce) molar ratio (NiCeOx-4) demonstrated excellent catalytic performance for propane oxidation. Furthermore, the preparation method strongly affected the morphology and surface structure of the NiCeOx-4 catalyst as well as its catalytic activity for propane oxidation. The NiCeOx-4 catalyst that was prepared with the hydrothermal method exhibited a better catalytic performance compared with catalysts that were prepared by the co-precipitation method, sol-gel method and physical mixing of pure NiO and CeO2 powders. The results demonstrated that Ni-containing CeO2 (NiCeOx) nanoparticles were located on the surface of the NiCeOx-4 catalyst that was prepared using the hydrothermal method. As a result, the NiCeOx-4 catalyst had strong reducibility, a large number of active oxygen species, and strong ability to break the CH bond of propane, which led to higher catalytic activity for propane combustion.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.08.068
      Issue No: Vol. 225 (2017)
  • Effect of cold Ar plasma treatment on the catalytic performance of Pt/CeO2
           in water-gas shift reaction (WGS)
    • Authors: Laura Pastor-Pérez; Victor Belda-Alcázar; Carlo Marini; M. Mercedes Pastor-Blas; Antonio Sepúlveda-Escribano; Enrique V. Ramos-Fernandez
      Pages: 121 - 127
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Laura Pastor-Pérez, Victor Belda-Alcázar, Carlo Marini, M. Mercedes Pastor-Blas, Antonio Sepúlveda-Escribano, Enrique V. Ramos-Fernandez
      The effect of Ar plasma treatment on the catalytic performance of Pt/CeO2 has been studied. The catalyst was activated using different procedures separately or in combination: calcination, reduction under pure H2 and cold Ar plasma treatment. The resulting materials were characterized by X-ray photoelectron spectroscopy, X-ray adsorption near edge structure and temperature-programmed reduction with H2. The resulting materials were tested in the water-gas shift reaction (WGS). It has been found that the combination of calcination, plasma and hydrogen treatments leads to a very active catalyst for WGS. Furthermore, the catalyst structure–performance relationship has been assessed. The plasma treatment generated electron-enriched Pt particles which show a very strong interaction with the ceria support. This favoured CO chemisorption and increased the reducibility of the support, which takes part in the WGS the reaction by favouring water splitting.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.065
      Issue No: Vol. 225 (2017)
  • Highly efficient Cu-decorated iron oxide nanocatalyst for low pressure CO2
    • Authors: Avik Halder; Martina Kilianová; Bing Yang; Eric C. Tyo; Soenke Seifert; Robert Prucek; Aleš Panáček; Petr Suchomel; Ondřej Tomanec; David J. Gosztola; David Milde; Hsien-Hau Wang; Libor Kvítek; Radek Zbořil; Stefan Vajda
      Pages: 128 - 138
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Avik Halder, Martina Kilianová, Bing Yang, Eric C. Tyo, Soenke Seifert, Robert Prucek, Aleš Panáček, Petr Suchomel, Ondřej Tomanec, David J. Gosztola, David Milde, Hsien-Hau Wang, Libor Kvítek, Radek Zbořil, Stefan Vajda
      We report a nanoparticulate iron oxide based catalyst for CO2 conversion with high efficiency at low pressures and on the effect of the presence of copper on the catalyst’s restructuring and its catalytic performance. In situ X-ray scattering reveals the restructuring of the catalyst at the nanometer scale. In situ X-ray absorption near edge structure (XANES) shows the evolution of the composition and oxidation state of the iron and copper components under reaction conditions along with the promotional effect of copper on the chemical transformation of the iron component. X-ray diffraction (XRD), XANES and Raman spectroscopy proved that the starting nanocatalyst is composed of iron oxides differing in chemical nature (α-Fe2O3, Fe3O4, FeO(OH)) and dimensionality, while the catalyst after CO2 conversion was identified as a mixture of α-Fe, Fe3C, and traces of Fe5C2. The significant increase of the rate CO2 is turned over in the presence of copper nanoparticles indicates that Cu nanoparticles activate hydrogen, which after spilling over to the neighbouring iron sites, facilitate a more efficient conversion of carbon dioxide.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.047
      Issue No: Vol. 225 (2017)
  • Hollow CaTiO3 cubes modified by La/Cr co-doping for efficient
           photocatalytic hydrogen production
    • Authors: Ruinan Wang; Shuang Ni; Gang Liu; Xiaoxiang Xu
      Pages: 139 - 147
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Ruinan Wang, Shuang Ni, Gang Liu, Xiaoxiang Xu
      In this work, we have applied microstructure management and doping techniques to conventional wide band gap semiconductor CaTiO3 with the aim to improve its light absorption and photocatalytic activity. A series of La/Cr co-doping hollow CaTiO3 cubes have been successfully prepared by a template-free hydrothermal method. Their crystal structures, microstructures, optical absorption and photocatalytic hydrogen production have been systematically investigated. Our results suggest that hollow CaTiO3 owns a higher light absorption than solid one and demonstrates a much better photocatalytic activity both under full range (λ≥250nm) and visible light illumination (λ≥400nm). These improvements probably originate from the peculiar hollow microstructures that increase photon-matter interactions and shorten the charge migration pathways. The photocatalytic activity for hydrogen production has been further studied by varying the La/Cr content in CaTiO3. An optimal doping point at 5% La/Cr doping level has been reached for full range illumination with apparent quantum efficiency approaching ∼2.41%. Nevertheless, the activity under visible light illumination shows a clear dependence on doping level with highest apparent quantum efficiency ∼0.40% at 20% La/Cr doping level. DFT calculations reveal the critical role of Cr in forming a new spin-polarized valence band inside the original band gap of CaTiO3 therefore is responsible for band gap reduction and visible light photocatalysis. This work here highlights the importance of microstructure control to the photocatalytic performance and shall shed a light on the design and development of efficient photocatalytic materials/systems.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.061
      Issue No: Vol. 225 (2017)
  • A novel thiocarbamide functionalized graphene oxide supported bimetallic
           monodisperse Rh-Pt nanoparticles (RhPt/TC@GO NPs) for Knoevenagel
           condensation of aryl aldehydes together with malononitrile
    • Authors: Betül Şen; Esma Hazal Akdere; Aysun Şavk; Emine Gültekin; Özge Paralı; Haydar Göksu; Fatih Şen
      Pages: 148 - 153
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Betül Şen, Esma Hazal Akdere, Aysun Şavk, Emine Gültekin, Özge Paralı, Haydar Göksu, Fatih Şen
      Functionalization of the graphene provides various possibilities to improve the use of the graphene and to provide more chemical conversion to the graphene. In order to enhance its chemical and physical properties, the graphite which is mainly functionalized with heteroatom-based functional groups is followed intensively, but often results in the inoculation of heteroatoms as various functional groups. Here we show that the graphene oxide can be mainly functionalized with a single species of sulfur and can be reduced to form a graphene which is functionalized with monothiol at the same time. By the help of thiocarbamide-functionalized graphene oxide (TC@GO) the monodisperse rhodium/platinum nanoparticles (RhPt/TC@GO NPs) have been synthesized as promising catalysts for the Knoevenagel condensation to benzylidenemalononitrile derivatives of aryl aldehydes. The monodisperse RhPt/TC@GO NPs have been prepared via a facile method. The novel thiocarbamide-functionalized graphene oxide (TC@GO) supported rhodium/platinum nanoparticles (RhPt/TC@GO NPs) are identified by characterization techniques such as the Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The spectroscopic and morphological studies of the monodisperse RhPt/TNM@GO NPs indicate the highly crystalline form, well dispersity, ultrafine structure and colloidally stable NPs. After fully characterization of prepared nanoparticles, the novel nanocatalysts have been tried for the Knoevenagel condensation to benzylidenemalononitrile derivatives of aryl aldehydes and show excellent catalytic activity and a yield over 99% by the reaction at room temperature within 8–35min in the presence of malononitrile and derivatives of aldehyde. As a result, the prepared nanocomposites exhibit very good heterogeneous catalyst properties for Knoevenagel condensation reactions.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.067
      Issue No: Vol. 225 (2017)
  • Self-assembled synthesis of defect-engineered graphitic carbon nitride
           nanotubes for efficient conversion of solar energy
    • Authors: Zhao Mo; Hui Xu; Zhigang Chen; Xiaojie She; Yanhua Song; Pengcheng Yan; Li Xu; Yucheng Lei; Shouqi Yuan; Huaming Li
      Pages: 154 - 161
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Zhao Mo, Hui Xu, Zhigang Chen, Xiaojie She, Yanhua Song, Pengcheng Yan, Li Xu, Yucheng Lei, Shouqi Yuan, Huaming Li
      High-yield and uniform-size graphitic carbon nitride nanotubes (g-C3N4 nanotubes) with abundant nitrogen defects are synthesized for the first time, and just use melamine as a precursor, which embodies the concept of green, acid and alkali-free synthesis. And the morphology and performance are superior to the traditional molecular self-assembly (choose melamine and cyanuric acid as precursors), benefiting from melamine in situ turns into cyanuric acid and the release rate rather slowly. The g-C3N4 nanotubes show orderly morphology with length-diameter ratio of 30–70. The self-assembly of supramolecular intermediate is absolutely vital for the formation of g-C3N4 nanotubes with abundant nitrogen defects. A detailed process for the formation of defective g-C3N4 nanotubes is discussed. The g-C3N4 nanotubes exhibit excellent hydrogen evolution rate (118.5μmolh−1), which is superior to the pure g-C3N4. The quantum efficiency of g-C3N4 nanotubes under irradiation at 420nm is achieved to 6.8%, which is in the front rank of one dimension (1D) g-C3N4 structure, like g-C3N4 nanotubes, nanowires and nanorods. The improved photocatalytic performance benefits from the tubular structure and the nitrogen defects, which lead to the improved optical absorption, the more exposed active edges, the enhanced transfer and separation efficiency of the photogenerated electron-hole pairs, the higher surface area, fast and long-distance electron transport, the longer fluorescence lifetime and the nitrogen defects can act as the active sites. The g-C3N4 nanotubes also have broad applications in environmental treatement and photoelectrochemical detection of organic dyes. Additionally, the molecular self-assembled method can be a promising strategy for the shape-controlled synthesis of the other materials, like metal oxides and metal sulfides.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.041
      Issue No: Vol. 225 (2017)
  • Proposed mechanisms for the removal of nitrate from water by platinum
           catalysts supported on polyaniline and polypyrrole
    • Authors: M. Jesús García-Fernández; M. Mercedes Pastor-Blas; Florence Epron; Antonio Sepúlveda-Escribano
      Pages: 162 - 171
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): M. Jesús García-Fernández, M. Mercedes Pastor-Blas, Florence Epron, Antonio Sepúlveda-Escribano
      Platinum nanoparticles have been synthesized on polyaniline (PANI) and polypyrrole (PPy) as supports using H2PtCl6 as metal precursor and a reducing treatment with cold Ar plasma. The catalytic activity of the polymer-supported catalysts in the reduction of aqueous nitrate with H2 at room temperature was evaluated. These systems are able to considerably decrease the concentration of nitrate in water in only 5min. The mechanism of the nitrate abatement process is determined by the nature of the conducting polymer. The nitrogen functionalities in polyaniline are external to the ring system, and favor nitrate retention at the platinum complex either by the formation of an adduct or by nitrate participating as a ligand. In contrast, polypyrrole possesses aromatic nitrogen atoms with a considerably more important steric hindrance. In this case, ion exchange between the counter ions in the doped polymer (SO4 2−) and nitrate from water is produced, followed by reduction of nitrate by hydrogen chemisorbed on the platinum nanoparticles.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.064
      Issue No: Vol. 225 (2017)
  • Plasmonic Cu nanoparticle on reduced graphene oxide nanosheet support: An
           efficient photocatalyst for improvement of near-infrared photocatalytic H2
    • Authors: Piyong Zhang; Ting Song; Tingting Wang; Heping Zeng
      Pages: 172 - 179
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Piyong Zhang, Ting Song, Tingting Wang, Heping Zeng
      Cu nanoparticles (NPs) are low-cost plasmonic metals and have been used for photocatalytic hydrogen evolution due to their surface plasmon resonance (SPR) effect. An efficient photocatalyst consisting of plasmonic Cu NPs on reduced graphene oxide (rGO) nanosheets support (Cu/rGO) is successfully prepared by a facile in-situ photoreduction process to form multiple nanoscale junctions for enhancement of photocatalytic hydrogen evolution. Compared to individual Cu NPs, the coupling to rGO nanosheets produces a higher photocatalytic ability with the highest H2 evolution rate of 59mmolg−1 h−1 for sample C, which contains 1.0wt% of rGO nanosheets. The rGO nanosheet possesses an extremely high conductivity and, can accept and transfer photogenerated electrons with no barrier. Therefore, recombination of photoinduced charges can be efficiently suppressed and the accepted electrons can be rapidly transferred to reactive sites for H2 evolution across its two-dimensional plane. More importantly, a near-infrared photocatalytic activity for sample C was obtained under monochromatic light irradiation at 800 and 900nm due to the broad spectrum response of plasmonic Cu NPs. Furthermore, a possible reaction mechanism is proposed for the photocatalytic activity improvement as well as the detailed charge transfer condition.
      Graphical abstract image

      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.076
      Issue No: Vol. 225 (2017)
  • Synergistic hollow CoMo oxide dual catalysis for tandem oxygen transfer:
           Preferred aerobic epoxidation of cyclohexene to 1,2-epoxycyclohexane
    • Authors: Wenzhou Zhong; Mengqiao Liu; Jing Dai; Jian Yang; Liqiu Mao; Dulin Yin
      Pages: 180 - 196
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Wenzhou Zhong, Mengqiao Liu, Jing Dai, Jian Yang, Liqiu Mao, Dulin Yin
      The CoMo hollow bimetallic oxide has been exploited in the aerobic epoxidation of cyclohexene containing labile allylic hydrogen atoms using ethylbenzene as a solvent. Cooperativity between Co(II) and Mo(VI) sites consisting of CoOMo or Mo−Oδ−⋯Coδ+ unit on hollow oxide surfaces is investigated for controlling preferred epoxidation catalysis via tandem oxygen transfer. Various characterization techniques like XRD diffraction, N2 physisorption, TEM, and Raman, XPS, Infrared, and UV–vis spectroscopies are employed to reveal the relationship between structure of active sites and catalytic performance. Together with these comprehensive experimental and computational studies, in this unique tandem catalytic process, Co(II) sites effectively mediate the first step of the overall oxidation cycle yielding a phenylethylperoxy radical by oxygen activation [Co(II) to Co(III) O2 − to phenylethyl radical and finally to a phenylethylperoxy radical]. On the other hand, Mo(VI) sites are shown to be the excellent catalytic species for the subsequent epoxidation step by the transfer of oxygen atom of the phenylethylperoxy radical to cyclohexene. Hence, a 59% epoxidation selectivity with 33% cyclohexene conversion is accomplished through the required combination of Co(II) and Mo(VI) (2:1), allowing to tune epoxidation efficiency toward higher driving forces (relative to oxygenation of allylic hydrogen atom). This remarkably different catalytic performances between Co(II) and Mo(VI) can be attributed to the stronger overall polarization ability of Mo(VI) toward σ* OO orbital of the OO unit derived from its d-type orbitals, which helps the donor-acceptor interactions with the double bond.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.074
      Issue No: Vol. 225 (2017)
  • Enhanced photocatalytic removal of phenol from aqueous solutions using ZnO
           modified with Ag
    • Authors: V. Vaiano; M. Matarangolo; J.J. Murcia; H. Rojas; J.A. Navío; M.C. Hidalgo
      Pages: 197 - 206
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): V. Vaiano, M. Matarangolo, J.J. Murcia, H. Rojas, J.A. Navío, M.C. Hidalgo
      Different photocatalysts based on commercial ZnO modified by silver photodeposition were prepared in this work. The samples were characterized by X-ray fluorescence spectrometry (XRF), specific surface area (SSA), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and UV–vis diffuse reflectance (UV–vis DRS). XRD and XPS showed that Ag/ZnO samples are composed of metallic Ag (Ag0) and ZnO structure was identified. Furthermore, TEM analysis evidenced that the number of silver particles increased with the Ag content. At last, UV–vis DRS results revealed a reflectance band for Ag/ZnO samples, ascribed to the surface plasmon resonance (SPR) absorption of metal silver particles. Commercial ZnO and Ag/ZnO samples were evaluated in the phenol removal under UV light irradiation. It was observed an enhancement of photocatalytic phenol removal from aqueous solutions by silver addition in comparison to commercial ZnO. In particular, the phenol removal increased with the silver content from 0.14 to 0.88wt%, after this content (i.e 1.28wt%) the phenol degradation significantly decreased indicating that the optimal Ag content was equal to 0.88wt%. The influence of the best photocatalyst dosage and the change of the initial phenol concentration in solution were also investigated in this work and the best photocatalytic performance was obtained by using 50mgL−1 of phenol initial concentration and 0.15gL−1 of photocatalyst dosage. Finally, the optimized Ag/ZnO photocatalyst was employed for the treatment of a real drinking wastewater containing phenol in which the almost total phenol removal was achieved after 180min of UV irradiation time.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.075
      Issue No: Vol. 225 (2017)
  • Design of catalytic carbon nanotube-based reactor for water denitration
           – The impact of active metal confinement
    • Authors: Sanja Panić; Ákos Kukovecz; Goran Boskovic
      Pages: 207 - 217
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Sanja Panić, Ákos Kukovecz, Goran Boskovic
      The catalytic reduction of nitrate to N2 represents the efficient water remediation technique in terms of the achieved nitrate depletion, but still with a main drawback – the production of ammonia as the undesired product. Therefore, efforts are undertaken to solve the problem, in terms of both reactor and catalyst design. Usage of internal cavities of carbon nanotubes (CNTs) may be a solution, both as a catalyst support and chemical nanoreactor. The aim of this work was to examine the activity and selectivity of Pd-Cu active phase located inside the carbon nanotubes – the confinement effect. Due to more accurate analysis of this effect, catalytic behavior of the metal nanoparticles deposited on the CNT exterior walls was also tested. Positioning of the active metal phase, i.e. exclusively inside or outside the CNTs, was promoted by previous CNTs cutting (via catalytic oxidation) and using solvents of different surface tension. The results of catalytic tests revealed the hindering effect of confined metal nanoparticles, while the externally deposited ones can be portrayed by superior performances in terms of both their activity and selectivity. The unexpected result was explained by a negative impact of confined particles due to their electron deficiency, as well as their size determining the second step of denitration reaction as a structure sensitive one.
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      PubDate: 2017-12-13T10:18:37Z
      DOI: 10.1016/j.apcatb.2017.11.078
      Issue No: Vol. 225 (2017)
  • Highly enhanced visible light photocatalysis and in situ FT-IR studies on
           Bi metal@defective BiOCl hierarchical microspheres
    • Authors: Hong Wang; Wendong Zhang; Xinwei Li; Jieyuan Li; Wanglai Cen; Qiuyan Li; Fan Dong
      Pages: 218 - 227
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Hong Wang, Wendong Zhang, Xinwei Li, Jieyuan Li, Wanglai Cen, Qiuyan Li, Fan Dong
      3D plasmonic Bi metal@defective BiOCl hierarchical microspheres were constructed by a one-step solvothermal method. The effects of solvent thermal temperature on the microstructure and the photocatalytic performance were investigated. The photocatalyst prepared at 200°C (Bi/BiOCl-200) showed most efficient visible photocatalytic activity for NOx removal. The enhanced activity can be ascribed to synergistic effects of oxygen vacancies and Bi metals. The oxygen vacancies in BiOCl induce the formation of an intermediate level to allow electrons transition from the valence band to intermediate level and then to the conduction band as revealed by density functional theory (DFT). The surface plasmon resonance (SPR) effect of elemental Bi enables the improvement of the visible light absorption efficiency and the promotion of the charge carrier separation as evidenced from the charge difference distribution between Bi atoms and Bi-O layers in BiOCl. The NO adsorption and reaction processes on Bi/BiOCl-200 were dynamically monitored by in situ infrared spectroscopy (FTIR). The mechanism of Bi metals and oxygen vacancies co-mediated photocatalytic performance on Bi/BiOCl was proposed based on the results of intermediate products analysis, radicals trapping and DFT calculation. The present work could provide new insights into the mechanistic understanding of the non-noble metal Bi-based plasmonic photocatalysts and offer a new technique to reveal the mechanism of gas-phase photocatalytic reaction.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.079
      Issue No: Vol. 225 (2017)
  • Mechanism insight into rapid photocatalytic disinfection of Salmonella
           based on vanadate QDs-interspersed g-C3N4 heterostructures
    • Authors: Rong Wang; Xiangyu Kong; Wentao Zhang; Wenxin Zhu; Lunjie Huang; Jing Wang; Xu Zhang; Xinnan Liu; Na Hu; Yourui Suo; Jianlong Wang
      Pages: 228 - 237
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Rong Wang, Xiangyu Kong, Wentao Zhang, Wenxin Zhu, Lunjie Huang, Jing Wang, Xu Zhang, Xinnan Liu, Na Hu, Yourui Suo, Jianlong Wang
      Photocatalytic disinfection, which is a readily reliable method in most climates, holds great promise to significantly reduce the microbial contamination in modern industry. Here we report that vanadate quantum dots-interspersed graphitic carbon nitride (vanadate QDs/g-C3N4 ) can achieve efficient inactivation of Salmonella by harvesting a substantial visible light. Detailed characterization through SEM-EDS, TEM, XRD, FT-IR, and XPS confirmed the formation of the composites. Owing to the efficient reactive oxygen species (ROS) production between vanadate QDs and g-C3N4, the bactericidal efficiency of AgVO3 QDs/g-C3N4 could reach 96.4% toward Salmonella in a concentration of 0.75mg/mL after 10min visible-light illumination. More importantly, scavenger experiments of different reactive species proved that the photoinduced electron generated at the oxidation site of AgVO3/g-C3N4 play a major role as oxidative species. Fluorescent-based cell live/dead test and membrane potentials were applied to demonstrate the integrity of cell membranes. Furthermore, the SEM technology, PCR and BCA protein assay were employed to verify the bacterial decomposition as well as leakage of bacterial cell contents toward Salmonella. Sterilization experiments of Staphylococcus aureus revealed that our composites have broad spectrum antimicrobial activity for both Gram-negative and Gram-positive bacteria under visible light. The results showed that the generation of high ROS could attack the bacterial cells membrane, and ultimately disrupt the cell metabolism through bacterial contents, which provided a feasible method for eliminating the microbial contaminated water.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.060
      Issue No: Vol. 225 (2017)
  • Aqueous-phase synthesis of metal hydroxide nanoplates and platinum/nickel
           hydroxide hybrid nanostructures and their enhanced electrocatalytic
    • Authors: Euiyoung Jung; Hee-Young Park; Ahyoung Cho; Jong Hyun Jang; Hyun S. Park; Taekyung Yu
      Pages: 238 - 242
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Euiyoung Jung, Hee-Young Park, Ahyoung Cho, Jong Hyun Jang, Hyun S. Park, Taekyung Yu
      We successfully synthesized metal hydroxide (Ni(OH)2 and Co(OH)2) nanoplates and platinum/nickel hydroxide hybrid nanostructures (Pt/Ni(OH)2) in an aqueous solution. Transmission electron microscopy studies of the Pt/Ni(OH)2 hybrid nanostructures revealed that a number of 3 nm-sized Pt nanoparticles were well dispersed on the surface of each Ni(OH)2 nanoplate. The Pt/Ni(OH)2 hybrid nanostructures exhibited enhanced electrocatalytic properties due to synergetic effect of Ni(OH)2 and Pt.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.054
      Issue No: Vol. 225 (2017)
  • Enhancing sulfacetamide degradation by peroxymonosulfate activation with
           N-doped graphene produced through delicately-controlled nitrogen
           functionalization via tweaking thermal annealing processes
    • Authors: Xiao Chen; Wen-Da Oh; Zhong-Ting Hu; Yuan-Miao Sun; Richard D. Webster; Shu-Zhou Li; Teik-Thye Lim
      Pages: 243 - 257
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Xiao Chen, Wen-Da Oh, Zhong-Ting Hu, Yuan-Miao Sun, Richard D. Webster, Shu-Zhou Li, Teik-Thye Lim
      Nitrogen-doped graphenes (NG) fabricated through thermal annealing of graphene oxide (GO) and urea was applied to activate peroxymonosulfate (PMS) for sulfacetamide (SAM) degradation. The contents of reactive functional groups (graphitic N, pyridinic N, pyrrolic N, nitric oxide and CO) and catalytic performance of NG were delicately controlled by adjusting thermal annealing temperature. Thermal annealing temperature of ≥500°C was required to produce the NG endowed with catalytic activity for SAM degradation via PMS activation. NG600 (NG prepared at 600°C) with a high N doping level (16.0wt%) and a most optimum amount of pyridinic N (38.4%N), pyrrolic N (31.8%N), graphitic N (25.9%N) and CO groups (43.7%O) exhibited the most outstanding catalytic activity to activate PMS. NG600 with the controlled N bonding configurations possessed a higher SAM degradation efficiency than NGs prepared via other optimized synthesis methods The specific surface area (SSA) contributed less significantly than N doping to the SAM degradation performance. Increments in the PMS dosage and catalyst loading were both conducive to the catalytic performance of NG. The presence of NO3 − in the NG600/PMS system had a negligible influence on SAM degradation but Cl− and humic acid decreased the SAM degradation rate. Experiments using chemical scavengers and electron paramagnetic resonance (EPR) study revealed that SAM degradation process follows predominantly the radical pathway with sulfate radical (SO4 −) as the main reactive oxygen species over the non-radical pathway. Density functional theory (DFT) calculations suggest that graphitic N can facilitate PMS adsorption on the NG and SAM degradation. This study improves the understanding on the role of different surface N functional groups of NG in the PMS activation.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.071
      Issue No: Vol. 225 (2017)
  • Simultaneous oxidation of alcohols and hydrogen evolution in a hybrid
           system under visible light irradiation
    • Authors: Fei Li; Yong Wang; Jian Du; Yong Zhu; Congying Xu; Licheng Sun
      Pages: 258 - 263
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Fei Li, Yong Wang, Jian Du, Yong Zhu, Congying Xu, Licheng Sun
      Water oxidation as a multi-electron transfer and endothermal reaction has been considered to be the bottleneck of solar-driven water splitting into oxygen and hydrogen. Herein, an alternative approach for solar energy conversion is developed by coupling H2 generation with the selective oxidation of alcohol. In a closed redox system containing molecular ruthenium catalyst (RuCat) and Pt modified g-C3N4 (Pt-g-C3N4) composite, hydrogen production is concomitant with the oxidation of benzyl alcohols to aldehydes with over 99% selectivity in the presence of visible light and pure water. By contrary, the system lacking molecular catalyst only exhibits low to moderate selectivities towards aldehydes. The remarkably improved selectivity is attributed to the formation of highly active Ru(IV)=O intermediate through efficient hole transfer from g-C3N4 to RuCat.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.072
      Issue No: Vol. 225 (2017)
  • The curious relationship of sintering to activity in supported gold
           catalysts for the hydrochlorination of acetylene
    • Authors: Kerry C. O’Connell; John R. Monnier; J.R. Regalbuto
      Pages: 264 - 272
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Kerry C. O’Connell, John R. Monnier, J.R. Regalbuto
      Gold catalysts for the hydrochlorination of acetylene are currently being studied as an environmentally benign replacement for industrial mercuric chloride catalysts, which undergo reduction and subsequent sublimation into the atmosphere. In this work the method of strong electrostatic adsorption was used with a cationic gold precursor to controllably deposit the gold precursors over a variety of activated carbon and metal oxide supports. The catalysts were characterized by XRD, STEM, and XPS before and after reaction or aging at temperature (180°C) in HCl. The synthesis procedure resulted in highly dispersed Au nanoparticles (usually below the 1.5nm limit of detection and some from 2 to 3nm) over all supports. The series of catalysts exhibited an unusual relationship of sintering to activity; the catalysts which best anchored the Au crystallites were the least active; titania and silica catalysts showed almost no sintering and were virtually inactive, and even a graphitic carbon catalyst exhibited good anchoring but very poor activity. The sintering was caused by the HCl atmosphere and not the temperature; catalysts submitted to the reaction temperature in He were stable. It would appear that the metal nanoparticles, and Au at the edges of metal nanoparticles, are inactive. The current results support recent reports in the literature that the active sites are derived from isolated Au ions, but we can conclude that oxidized amorphous carbon also plays a key role in generating the active site. In this environment the active species is highly mobile and susceptible to sintering.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.001
      Issue No: Vol. 225 (2017)
  • Sulfide oxide XZnSO (X=Ca or Sr) as novel active photocatalytic water
           splitting solar-to-hydrogen energy conversion
    • Authors: A.H. Reshak
      Pages: 273 - 283
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): A.H. Reshak
      The photocatalytic, structural and transport properties of the newly synthesized sulfide oxide CaZnSO and SrZnSO compounds are comprehensively investigated by means of first and second-principles calculation in order to explain the semiconductor's ‘photo-excitation' state mechanism in CaZnSO and SrZnSO. At the same time, the influence of the substitution of Ca2+ by Sr2+ on the structural properties and, hence, on the photocatalytic properties, are investigated. The optical conductivity and the absorption level exhibit an obvious enhancement from the ultraviolet to the visible light region when we move from Ca to Sr. This shows that the absorption edge moves from λ=387.4→λ=442.7nm, which corresponds to the direct optical band gap of 3.2eV→2.8eV, which is well matched with the solar spectrum and the sufficient negative conduction band potential for reduction of H+/H2. The calculated electronic band structure and the angular momentum character of various structures confirm that CaZnSO and SrZnSO possess a direct fundamental energy band gap of about 3.7eV (CaZnSO)→3.1eV (SrZnSO), and the electronic charge distribution reveals a clear map of the electronic charge transfer and the chemical bonding. Furthermore, the carrier concentration (n) as a function of chemical potential at three constant temperatures (T) and n as a function of T at fixed chemical potential were calculated. It was found that n increases exponentially with increasing T and reveals that the CaZnSO and SrZnSO are p-type semiconductors. Based on these results, one can conclude that CaZnSO and SrZnSO satisfied all requirements to be an efficient photocatalyst. This will greatly improve the search efficiency and greatly help experiments to save resources in the exploration of new photocatalysts with good photocatalytic performance.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.006
      Issue No: Vol. 225 (2017)
  • A photochemical synthesis route to typical transition metal sulfides as
           highly efficient cocatalyst for hydrogen evolution: from the case of
    • Authors: Hui Zhao; Huizhen Zhang; Guanwei Cui; Yuming Dong; Guangli Wang; Pingping Jiang; Xiuming Wu; Na Zhao
      Pages: 284 - 290
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Hui Zhao, Huizhen Zhang, Guanwei Cui, Yuming Dong, Guangli Wang, Pingping Jiang, Xiuming Wu, Na Zhao
      Precise deposition of cocatalysts on the outlet points of photo-generated electrons is helpful for highly efficient photocatalytic hydrogen evolution. Up to now, photochemical preparation of hydrogen production cocatalysts composed of earth-abundant elements is still great challenging and rarely reported. Herein, from the case of NiS/g-C3N4, a general photochemical synthesis route to typical transition metal sulfides as cocatalyst for hydrogen evolution was proposed. NiS were prepared by a facile and rapid photochemical method. The content of deposited NiS can be simply adjusted by the change of irradiation time. The optimized photocatalytic hydrogen evolution rate mounted up to 16 400μmolg−1 h−1 with 0.76wt% NiS loading, which is about 2500 times higher than that of pure g-C3N4. The photocatalytic H2 evolution rate was stable after 40h. The turnover number (TON) reached 1230 000 in 52h with a turnover frequency (TOF) of 23 600 for NiS. Furthermore, the hydrogen evolution of the NiS/g-C3N4 composite photocatalyst reached 28.3mmolg−1 during 7h under natural sunlight. The presence of NiS cocatalyst can efficiently promote the separation of photogenerated electron-hole pairs of g-C3N4, which was supported by the steady-state photoluminescence spectroscopy and photoelectro- chemical analyses.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.083
      Issue No: Vol. 225 (2017)
  • Confined-interface-directed synthesis of Palladium single-atom catalysts
           on graphene/amorphous carbon
    • Authors: Jiangbo Xi; Hongyu Sun; Da Wang; Zheye Zhang; Xianming Duan; Junwu Xiao; Fei Xiao; Limin Liu; Shuai Wang
      Pages: 291 - 297
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Jiangbo Xi, Hongyu Sun, Da Wang, Zheye Zhang, Xianming Duan, Junwu Xiao, Fei Xiao, Limin Liu, Shuai Wang
      The maximized atomic efficiency of supported catalysts is highly desired in heterogeneous catalysis. Therefore, the design and development of active, stable, and atomic metal-based catalysts remains a formidable challenge. To tackle these problems, it is necessary to investigate the interaction between single atoms and supports. Theoretical calculations indicate that the Pd binding strength is higher on graphene/amorphous carbon (AC) than that on graphene or AC substrate. Based on these predictions, we present a facile confined-interface-directed synthesis route for the preparation of single-atom catalysts (SACs) in which Pd atoms are well-dispersed on the interface of double-shelled hollow carbon nanospheres with reduced graphene oxide (RGO) as the inner shell and AC as the outer shell. Owing to the synergetic effect of the RGO/AC confined interface and the atomically dispersed Pd, the as-made RGO@AC/Pd SAC achieves the maximum atomic efficiency (catalytic activity) of Pd species and exhibits an excellent stability in chemical catalysis. This confined-interface-directed synthesis method provides a novel direction to maximize the atomic efficiency, improve the activity, and enhance the stability of metal-based catalysts.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.057
      Issue No: Vol. 225 (2017)
  • Thermo-photo degradation of 2-propanol using a composite ceria-titania
           catalyst: Physico-chemical interpretation from a kinetic model
    • Authors: Mario J. Muñoz-Batista; Ana M. Eslava-Castillo; Anna Kubacka; Marcos Fernández-García
      Pages: 298 - 306
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Mario J. Muñoz-Batista, Ana M. Eslava-Castillo, Anna Kubacka, Marcos Fernández-García
      This work describes a study carried out to construct and determine a kinetic formalism for the gas-phase degradation of 2-propanol using a combined thermo-photo based process. Outstanding catalytic performance was observed for a composite ceria-titania system with respect its parent ceria and titania reference systems. Thermo-photo as well as parallel photo- and thermal-alone experiments were carried out to interpret catalytic behavior. The kinetic experiments were conducted using a continuous flow reactor free of internal and external mass-heat transfer and designed using a Box-Behnken formalism. The kinetic expression developed for the thermo-photo degradation process explicitly includes the effect of the photon absorption in the reaction rate and leads to a mathematical formula with two components having different physico-chemical nature. This fact is used to settle down a fitting procedure using two steps (two separated experimental sets of data concerning temperature, light intensity, oxygen, water and/or 2-propanol concentrations) with, respectively, four and three parameters. The kinetic formalism was validated by fitting the experimental data from these two independent experiments, rendering a good agreement with the model predictions. The parameters coming from the kinetic modelling allow an interpretation of the catalytic properties of the ceria-titania catalyst, quantifying separately its enhanced performance (with respect to its parent systems) in the photonic and thermal components for the process. The procedure is applicable to a wide variety of thermo-photo processes in order to contribute to the understanding of their physical roots.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.073
      Issue No: Vol. 225 (2017)
  • Molten salt synthesis of tetragonal carbon nitride hollow tubes and their
           application for removal of pollutants from wastewater
    • Authors: Liang Tian; Junyi Li; Feng Liang; Junkai Wang; Saisai Li; Haijun Zhang; Shaowei Zhang
      Pages: 307 - 313
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Liang Tian, Junyi Li, Feng Liang, Junkai Wang, Saisai Li, Haijun Zhang, Shaowei Zhang
      Carbon nitride has attracted extensive attention because of its promising properties and great application potential in photocatalysis, electrocatalysis, bioimaging and biomedicine. In this work, carbon nitride with a novel morphology, i.e., tetragonal carbon nitride hollow tube (TCNT), was in-situ synthesized by a molten salt method at 450°C using melamine as the starting precursor. As-prepared TCNTs were 2–20μm long and 50–2000nm wide and possessed higher content of impurity nitrogen and larger specific surface area than conventional bulk g-C3N4 (B-CN). A possible salt-assisted self-assembly mechanism is believed to have dominated the formation of TCNTs. As-prepared TCNTs exhibited superior photocatalytic activities and adsorption performance for methylene blue and phenol degradation to B-CN, suggesting that they could be potentially used as a promising photocatalyst and adsorbent.
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      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.082
      Issue No: Vol. 225 (2017)
  • Novel photoactivation promotes catalytic abatement of CO on CuO mesoporous
           nanosheets with full solar spectrum illumination
    • Authors: Chongyang Zhou; Lei Cheng; Yuanzhi Li; Min Zeng; Yi Yang; Jichun Wu; Xiujian Zhao
      Pages: 314 - 323
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Chongyang Zhou, Lei Cheng, Yuanzhi Li, Min Zeng, Yi Yang, Jichun Wu, Xiujian Zhao
      The sample of CuO mesoporous nanosheets (CuO-MNS) was prepared by a facile method of the reaction between NaOH and copper ammonia complex formed from CuSO4 and ammonia aqueous solutions at 25°C. CuO-MNS shows greatly effective photothermocatalytic activity and excellent durability for the catalytic oxidation of CO (poisonous air pollutant) under the full solar spectrum illumination from a Xe lamp. Compared to commercial nonporous CuO and TiO2 (P25), the photothermocatalytic activity of CuO-MNS under the Xe lamp illumination is enhanced by 19.8 and 88.7 times, respectively. Under the UV–vis-IR illumination with the same light intensity, the photothermocatalytic activity of CuO-MNS is 331 times higher than its conventional photocatalytic activity. Impressively, CuO-MNS also demonstrates effective photothermocatalytic activity even under the λ>830nm infrared illumination. It is discovered that the greatly effective photothermocatalytic activity of CuO-MNS is attributed to effective solar-light-driven (SLD) thermocatalytic CO oxidation. The significantly enhanced photothermocatalytic activity of CuO-MNS as compared to the commercial nonporous CuO is attributed to the tremendously higher thermocatalytic activity of the former than the later. The results of CO-TPR, Raman, and density functional theory (DFT) calculations reveal that the formation of mesopores in CuO-MNS significantly improves the lattice oxygen activity of CuO, thus significantly enhancing thermocatalytic activity of CuO. Very interestingly, a novel photoactivation, completely unlike the well-known photocatalysis of photocatalytic semiconductors such as TiO2, is discovered to considerably promote the SLD thermocatalytic CO oxidation on CuO-MNS. By combining the experimental evidence of CO-TPR and O2-TPO in the dark and under the Xe lamp illumination as well as the theoretical evidence by the DFT calculations in the ground state and excited state, we reveal the origin of the novel photoactivation: the Xe lamp illumination considerably promotes the re-oxidation of the pre-reduced CuO-MNS, thus considerably enhancing the catalytic activity of CuO-MNS.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.081
      Issue No: Vol. 225 (2017)
  • NO oxidation on Fe- and Cu-zeolites mixed with BaO/Al2O3: Free oxidation
           regime and relevance for the NH3-SCR chemistry at low temperature
    • Authors: Tommaso Selleri; Federica Gramigni; Isabella Nova; Enrico Tronconi
      Pages: 324 - 331
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Tommaso Selleri, Federica Gramigni, Isabella Nova, Enrico Tronconi
      Oxidative activation of NO is commonly regarded as a key step in the low-temperature mechanism of Standard SCR on metal-promoted zeolite catalysts for NH3-SCR of NOx. In the present work, we systematically investigate the dynamics of NO oxidation as well as the reactivity of NO+NO2 with adsorbed and gas-phase NH3 on Fe-ZSM-5 and Cu-CHA catalysts, using chemical trapping techniques. The approach is based on physically mixing the metal promoted zeolite catalyst with a NOx trap material, i.e. BaO/Al2O3. We show that in these combined systems, as long as NOx storage sites are available, the initial rate of NO oxidative activation is substantially higher than over the metal promoted zeolite alone, as measured in conventional steady-state activity tests for NO oxidation to NO2. Similar dynamics with enhanced initial NO conversions are observed also in the case of metal promoted zeolite catalysts with preadsorbed NH3, suggesting a close analogy between the role of BaO in the chemical trapping runs and the role of adsorbed NH3 in Standard SCR conditions, both species removing effectively the NO oxidation products from the gas phase and therefore preventing their inhibitory action. These novel findings are relevant to estimate correctly the intrinsic kinetics of the NO oxidative activation over metal-promoted zeolite SCR catalysts, and may help to explain the so far unresolved divergence between the rate of NO oxidation to NO2 and the rate of the Standard SCR reaction. We show, in fact, that the rate of uninhibited NO oxidation is able to sustain the Standard SCR activity over both Fe- and Cu-zeolite catalysts.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.068
      Issue No: Vol. 225 (2017)
  • One-dimensional MgxTiyOx+2y nanostructures: General synthesis and enhanced
           photocatalytic performance
    • Authors: Guorui Yang; Ling Wang; Yanmei Zhao; Shengjie Peng; Jianan Wang; Dongxiao Ji; Zhe Wang; Wei Yan; Seeram Ramakrishna
      Pages: 332 - 339
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Guorui Yang, Ling Wang, Yanmei Zhao, Shengjie Peng, Jianan Wang, Dongxiao Ji, Zhe Wang, Wei Yan, Seeram Ramakrishna
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.062
      Issue No: Vol. 225 (2017)
  • Structure and surface properties of ceria-modified Ni-based catalysts for
           hydrogen production
    • Authors: S. Damyanova; B. Pawelec; R. Palcheva; Y. Karakirova; M.C. Capel Sanchez; G. Tyuliev; E. Gaigneaux; J.L.G. Fierro
      Pages: 340 - 353
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): S. Damyanova, B. Pawelec, R. Palcheva, Y. Karakirova, M.C. Capel Sanchez, G. Tyuliev, E. Gaigneaux, J.L.G. Fierro
      Series of Ni catalysts supported on alumina and mixed xCeO2-Al2O3 oxides with different CeO2 content (1–12 wt%) were prepared by impregnation method. The effect of CeO2 loading on the structure and catalytic properties of supported Ni catalysts in dry methane reforming was studied. The texture, structure and surface properties of the catalysts in their calcined, reduced and used state were studied by using different techniques such as: adsorption-desorption isotherms, XRD, UV–vis DRS, XPS, Raman, H2-TPR, EPR, TPO and TEM. Variation in the electronic environments of the cerium and nickel as a function of the CeO2 content and pretreatment was observed for CeO2-containing Ni catalysts. The couples Ni2+/Nio and Ce3+/Ce4+ were detected in the oxidic, reduced and spent ceria-loaded Ni catalysts. CeO2-containing Ni catalysts exhibited higher activity and stability with time on stream relative to that of alumina-supported Ni. The obvious difference in the behaviors of Ni/xCeO2-Al2O3 and Ni/Al2O3 was related to the difference in their dispersions. Small nanoparticles of 4.7–6.3 nm were observed for CeO2-modified catalysts assuring their high activity and resistance to carbon deposition. The highest activity and stability of Ni catalyst with 6 wt.% CeO2 was due to the higher electron density and accessibility of the active sites caused by the close contact between nickel and cerium species. While, Ni/Al2O3 catalyst exhibited low activity and carbon resistant due to the agglomeration of nickel particles up to 20 nm.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.002
      Issue No: Vol. 225 (2017)
  • Kinetics of CO2 methanation on a Ru-based catalyst at process conditions
           relevant for Power-to-Gas applications
    • Authors: Leonardo Falbo; Michela Martinelli; Carlo Giorgio Visconti; Luca Lietti; Claudia Bassano; Paolo Deiana
      Pages: 354 - 363
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Leonardo Falbo, Michela Martinelli, Carlo Giorgio Visconti, Luca Lietti, Claudia Bassano, Paolo Deiana
      In this paper we show that a 0.5wt.% Ru/γ-Al2O3 catalyst is appropriate to carry out the Sabatier reaction (CO2 methanation) under process conditions relevant for the Power-to-Gas application and we provide a kinetic model able to describe the CO2 conversion over a wide range of process conditions, previously unexplored. To achieve these goals, the effects of feed gas composition (H2/CO2 ratio and presence of diluents), space velocity, temperature and pressure on catalyst activity and selectivity are investigated. The catalyst is found stable when operating over a wide range of CO2 conversion values, with CH4 selectivity always over 99% and no deactivation, even when working with carbon-rich gas streams. The effect of water on the catalyst performance is also investigated and an inhibiting kinetic effect is pointed out. Eventually, the capacity of kinetic models taken from the literature to account for CO2 conversion under the explored experimental conditions is assessed. It is found that the kinetic model proposed by Lunde and Kester in 1973 (J. Catal. 30 (1973) 423) is able to describe satisfactorily the catalyst behavior in a wide range of CO2 conversion spanning from differential conditions to thermodynamic equilibrium, provided that a new set of kinetic parameters is used. It is shown however that a better fitting can be achieved by using a modified kinetic model, accounting for the inhibiting effect of H2O on CO2 conversion rate.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.066
      Issue No: Vol. 225 (2017)
  • Streamlining of the synthesis process of Pt/carbon xerogel
           electrocatalysts with high Pt loading for the oxygen reduction reaction in
           proton exchange membrane fuel cells applications
    • Authors: Anthony Zubiaur; Nathalie Job
      Pages: 364 - 378
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Anthony Zubiaur, Nathalie Job
      Pt/carbon xerogel catalysts were synthesized by different methods. The strong electrostatic adsorption (SEA) method, which consists in enhancing electrostatic interactions between the support and the precursor, was first modified in order to avoid any Pt loss (charge enhanced dry impregnation, CEDI). In a second step, the synthesis was rationalized to speed up the reduction (liquid phase reduction with sodium borohydride, NaBH4). The synthesis procedure was further simplified in order to obtain one-step procedures, such as (i) reduction of highly loaded platinum solution by sodium borohydride, (ii) formic acid reduction, and (iii) colloid synthesis. All the catalysts were analyzed by physicochemical and electrochemical methods. They are compared to a reference commercial catalyst (Tanaka). The best performances are obtained by the SEA, the CEDI and the formic acid reduced catalysts, the performance of which are at least equal to, or even higher (up to 20–25% in mass activity) than those of the commercial reference. From these three methods, the only one-step method is the formic acid reduction, which allows avoiding time-consuming drying and H2 reduction steps.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.059
      Issue No: Vol. 225 (2017)
  • CdS/CdSe co-sensitized brookite H:TiO2 nanostructures: Charge carrier
           dynamics and photoelectrochemical hydrogen generation
    • Authors: Yung-Shan Chang; Mingi Choi; Minki Baek; Ping-Yen Hsieh; Kijung Yong; Yung-Jung Hsu
      Pages: 379 - 385
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Yung-Shan Chang, Mingi Choi, Minki Baek, Ping-Yen Hsieh, Kijung Yong, Yung-Jung Hsu
      In this study, we have synthesized CdS/CdSe co-sensitized brookite TiO2 nanostructures with hydrogen doping (H:TiO2/CdS/CdSe) in a facile solution reaction and studied their PEC performances. Compared to undoped brookite TiO2, the H:TiO2/CdS/CdSe composites exhibit much enhanced photocurrent generation, which originates from the improved charge transfer kinetics endowed by hydrogen doping and sensitization. Time-resolved photoluminescence (PL) and electrochemical impendence spectroscopy (EIS) are employed to explore the charge transfer dynamics between sensitizers and TiO2 and charge carrier kinetics at the semiconductor/electrolyte interface. According to the analytical results, sensitizations of TiO2 are found to enhance the charge separation efficiency. Besides, the hydrogen doping into TiO2 generates oxygen vacancy states, providing additional charge transfer pathway and prohibiting charge recombination, beneficial for enhancing the PEC performances as well. Based on the charge dynamics data, we further develop charge transfer models for TiO2/CdS/CdSe and H:TiO2/CdS/CdSe. The findings from this work can help understanding the charge transfer dynamics in brookite TiO2-based composite systems as well as designing versatile photoelectrodes for solar energy conversion.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.063
      Issue No: Vol. 225 (2017)
  • Understanding the lattice composition directed in situ structural disorder
           for enhanced visible light photocatalytic activity in Bismuth iron niobate
    • Authors: Radha R.; Ravi Kumar Y.; Sakar M.; Rohith Vinod K.; Balakumar S.
      Pages: 386 - 396
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Radha R., Ravi Kumar Y., Sakar M., Rohith Vinod K., Balakumar S.
      Herein we report the cationic disorder dependent photocatalytic efficiency of pyrochlore type Bi1.33 Fe0.052Nb1.24Fe1.04O7-δ (BFNF) and Bi1.34Fe0.66Nb1.34O7-δ (BFN) nanoparticles (Nps) for the first time. Bi based photocatalytic materials endowed with lone pair of 6s2 electrons is additionally perturbed by nonstoichiometry and studied for its optoelectronic properties. Rietveld refinements show that the crystal structure is cubic and the space group is Fd 3 ¯ m. In BFNF Nps, Bi3+ cation on the eight coordinate pyrochlore A-site shows displacive disorder, as a consequence of its lone pair electronic configuration as well as due to higher iron concentration. The lattice vibrational analysis using Raman spectra is consistent with the displacive disorder of the pyrochlore. A quantitative chemical compositional and state analysis has been done using X-ray photoelectron spectroscopy. The band-gap energy (Eg) and band edge offset of BFNF and BFN NPs were estimated to be 2.43 and 2.56eV respectively by using UV–vis spectroscopy and the valence band XPS spectra. Under visible light, the BFNF NPs exhibits a much better visible-light-responsive photocatalytic performance than BFN NPs for the degradation of RhB and commercially available pharmaceutical acetoaminophen (Dolo 650). The mechanism of high photocatalytic activity was suggested on the basis of the photoluminescence spectra, electrochemical impedance spectra (EIS), and active species trapping measurements. Our findings indicated that the synergistic effect of higher degree of cationic disorder in BFNF NPs is responsible for favourable direct transition along with NBE (near bandedge) transition, efficient separation and migration of photoinduced charge carriers, thus resulting in the remarkably improved photocatalytic activity.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.004
      Issue No: Vol. 225 (2017)
  • Fragmented phosphorus-doped graphitic carbon nitride nanoflakes with broad
           sub-bandgap absorption for highly efficient visible-light photocatalytic
           hydrogen evolution
    • Authors: Hua-Bin Fang; Xiao-Hong Zhang; Jiaojiao Wu; Nan Li; Yan-Zhen Zheng; Xia Tao
      Pages: 397 - 405
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Hua-Bin Fang, Xiao-Hong Zhang, Jiaojiao Wu, Nan Li, Yan-Zhen Zheng, Xia Tao
      Graphitic carbon nitride (g-C3N4) has shown great promise in photocatalytic solar-energy conversion. However, photocatalytic activity of pristine g-C3N4 still remains restricted owing to its low surface area, insufficient visible-light harvesting, and ready charge recombination. Here, fragmented P-doped g-C3N4 nanoflakes (PCNNFs), which are prepared by a facile two-step processing combining P-doping via using phytic acid biomass as P source and urea as g-C3N4 precursor and nanostructure tailoring via a smart post-treatment, are reported. Particularly, PCNNFs exhibit narrowed sub-bandgap from valence band to the midgap states, extending light absorption up to 800 nm. The resultant PCNNFs sample shows a surface area of 223.2 m2 g−1, a highest value of P-doped g-C3N4 reported. The fragmented nanoflakes structure renders PCNNFs much shortened charge-to-surface migration distance in both vertical-plane and in-plane direction. Such PCNNFs are demonstrated to be highly efficient in charge transfer and separation. Attributed to the synergistic effect of P-doping and fragmented nanoflakes structure, PCNNFs exhibit a remarkable visible-light (>420 nm) photocatalytic H2 production rate of 15921 μmol h−1 g−1 and quantum efficiencies of 6.74% at 420 nm and 0.24% at 600 nm. Moreover, even under long wavelength light (>470 nm), PCNNFs still exhibit high H2 production rate of 9546 μmol h−1 g−1, over 62 times the rate of pure g-C3N4.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.11.080
      Issue No: Vol. 225 (2017)
  • Visible light-induced catalytic activation of peroxymonosulfate using
           heterogeneous surface complexes of amino acids on TiO2
    • Authors: Jonghun Lim; Dong-yeob Kwak; Fabian Sieland; Chuhyung Kim; Detlef W. Bahnemann; Wonyong Choi
      Pages: 406 - 414
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Jonghun Lim, Dong-yeob Kwak, Fabian Sieland, Chuhyung Kim, Detlef W. Bahnemann, Wonyong Choi
      Peroxymonosulfate (PMS) is being extensively investigated as an eco-friendly oxidant and various activation methods of PMS have been investigated. Here we demonstrated a new method of catalytic PMS activation, which employed amino acids as both a visible light sensitizer and a substrate to be degraded. Although PMS and amino acids do not absorb any visible light, the surface adsorption of amino acids on titania formed charge-transfer complexes that absorb visible light (λ > 420 nm). Serine and histidine were employed as main target amino acids and their surface complexes on TiO2 were characterized by various spectroscopic methods The ligand-to-metal charge transfer between amino acids and TiO2 enabled the absorption of visible light and the subsequent electron transfer catalytically activated PMS with generating sulfate radicals which were detected by electron paramagnetic resonance analysis. Based on various scavenger tests, amino acids seem to be degraded mainly by sulfate radical (radical pathway) and by a non-radical pathway (PMS serving primarily as an electron acceptor) to some extent. Amino acids were degraded with producing ammonium as a sole nitrogenous product in this process, whereas most advanced oxidation processes of amino acid generate not only ammonium but also nitrate and nitrite. The visible light-induced charge transfer characteristics of the amino acid-TiO2 complexes were demonstrated by the photoelectrochemical characterizations and the time-resolved laser spectroscopic analysis.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.025
      Issue No: Vol. 225 (2017)
  • Promoting the interfacial H2-evolution reaction of metallic Ag by Ag2S
           cocatalyst: A case study of TiO2/Ag-Ag2S photocatalyst
    • Authors: Huogen Yu; Wenjing Liu; Xuefei Wang; Fazhou Wang
      Pages: 415 - 423
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Huogen Yu, Wenjing Liu, Xuefei Wang, Fazhou Wang
      Metallic Ag has been widely demonstrated to be an excellent oxygen-reduction cocatalyst to significantly improve the photocatalytic decomposition performance of various organic substances. However, as a H2-evolution cocatalyst, the improved photocatalytic performance by metallic Ag is quite limited due to its low H2-evolution rate. In this study, for the well-known TiO2/Ag photocatalyst, Ag2S as the efficient H2-evolution active sites was selectively loaded on the metallic Ag surface to greatly promote the interfacial H2-evolution reaction rate. In this case, the TiO2/Ag-Ag2S sample was synthesized by a two-step process including the simple photoinduced deposition of metallic Ag on the TiO2 surface and the following in situ sulfidation of partial Ag into Ag2S. Photocatalytic experimental results indicated that the TiO2/Ag-Ag2S(40uL) photocatalysts clearly exhibited a significantly higher UV-light photocatalytic H2-evolution activity (119.11 μmol h−1) than the pure TiO2, TiO2/Ag and TiO2/Ag2S photocatalysts by a factor of 51.8, 3.9 and 3.6 times, respectively. On the basis of the present results, a synergistic effect of dual electron-cocatalyst (metallic Ag and Ag2S) is proposed for the improved photocatalytic H2-evolution activity, namely, the Ag-nanoparticle cocatalyst can steadily capture and transfer the photogenerated electrons from TiO2 surface, while the Ag2S cocatalyst is considered to be the interfacial active sites to promote the rapid H2-evolution reaction. This research may provide new strategies for the development of highly efficient photocatalytic materials used in various fields.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.026
      Issue No: Vol. 225 (2017)
  • Remarkably boosting catalytic H2 evolution from ammonia borane through the
           visible-light-driven synergistic electron effect of non-plasmonic
           noble-metal-free nanoparticles and photoactive metal-organic frameworks
    • Authors: Jin Song; Xiaojun Gu; Jia Cheng; Na Fan; Hao Zhang; Haiquan Su
      Pages: 424 - 432
      Abstract: Publication date: 5 June 2018
      Source:Applied Catalysis B: Environmental, Volume 225
      Author(s): Jin Song, Xiaojun Gu, Jia Cheng, Na Fan, Hao Zhang, Haiquan Su
      From the viewpoint of regulating and enriching the electron density of noble-metal-free nanoparticles (NPs) to remarkably enhance their catalytic activities in the reduction-dominated reactions, we synthesized a series of non-plasmonic Co and Ni nanoparticles (NPs) supported by NH2-functionalized photoactive and NH2-free non-photoactive metal-organic frameworks (MOFs) with different compositions and framework structures, which were used to catalyze H2 evolution from ammonia borane (NH3BH3) in aqueous solution under visible light irradiation at 298 K. The systematic investigation showed that the catalysts containing photoactive MOFs had higher activities than those containing non-photoactive MOFs under visible light irradiation though the photocatalytic activities of all the catalysts were enhanced in comparison with the activities in the dark. Specifically, the Co catalysts containing photoactive MOFs had the total turnover frequency (TOF) values in the range of 81.7–117.7 min−1, which were much higher than the values of reported noble-metal-free catalysts and were even comparable to the values of noble metal catalysts. The remarkably enhanced activities of the supported catalysts could be attributed to the visible-light-driven synergistic electron effect of semiconductor-like MOFs and non-plasmonic noble-metal-free NPs, which was verified by the increased photocurrent density of Co/MIL-101(Cr)-NH2. Moreover, the catalysts still had 100% of H2 selectivity and high activities after 25 runs of catalysis.
      Graphical abstract image

      PubDate: 2017-12-27T11:33:27Z
      DOI: 10.1016/j.apcatb.2017.12.024
      Issue No: Vol. 225 (2017)
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