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ENGINEERING (1195 journals)                  1 2 3 4 5 6 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 7)
3D Research     Hybrid Journal   (Followers: 19)
AAPG Bulletin     Full-text available via subscription   (Followers: 5)
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: 216)
Acta Geotechnica     Hybrid Journal   (Followers: 6)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 1)
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: 10)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 4)
Advanced Science     Open Access   (Followers: 5)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 5)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 6)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 18)
Advances in Artificial Neural Systems     Open Access   (Followers: 3)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 14)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 9)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 18)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 28)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in OptoElectronics     Open Access   (Followers: 5)
Advances in Physics Theories and Applications     Open Access   (Followers: 13)
Advances in Polymer Science     Hybrid Journal   (Followers: 40)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 35)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aerobiologia     Hybrid Journal   (Followers: 1)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 4)
AIChE Journal     Hybrid Journal   (Followers: 29)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access  
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: 16)
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: 7)
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: 5)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 6)
Applied Clay Science     Hybrid Journal   (Followers: 4)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 3)
Applied Nanoscience     Open Access   (Followers: 7)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 4)
Applied Sciences     Open Access   (Followers: 3)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
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: 8)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 2)
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: 7)
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: 7)
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: 3)
Batteries     Open Access   (Followers: 3)
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: 3)
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: 3)
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Biofuels Engineering     Open Access  
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 9)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 16)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 31)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 8)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 1)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription  
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: 3)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers, Droit, Sciences et Technologies     Open Access  
Calphad     Hybrid Journal  
Canadian Geotechnical Journal     Full-text available via subscription   (Followers: 13)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 40)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 7)
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: 6)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 5)
CEAS Space Journal     Hybrid Journal  
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: 21)
Clay Minerals     Full-text available via subscription   (Followers: 9)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Coal Science and Technology     Full-text available via subscription   (Followers: 4)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 4)
Coatings     Open Access   (Followers: 2)
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: 13)
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: 23)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 252)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 177)
Composites Part B : Engineering     Hybrid Journal   (Followers: 223)
Composites Science and Technology     Hybrid Journal   (Followers: 164)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 12)
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: 6)
Computer Science and Engineering     Open Access   (Followers: 17)
Computers & Geosciences     Hybrid Journal   (Followers: 25)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 5)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 4)
Computers and Geotechnics     Hybrid Journal   (Followers: 8)
Computing and Visualization in Science     Hybrid Journal   (Followers: 6)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 25)
Conciencia Tecnologica     Open Access  
Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 6)
Control and Dynamic Systems     Full-text available via subscription   (Followers: 7)
Control Engineering Practice     Hybrid Journal   (Followers: 40)
Control Theory and Informatics     Open Access   (Followers: 7)
Corrosion Science     Hybrid Journal   (Followers: 24)
CT&F Ciencia, Tecnologia y Futuro     Open Access  
CTheory     Open Access  
Current Applied Physics     Full-text available via subscription   (Followers: 4)

        1 2 3 4 5 6 | Last

Journal Cover Applied Catalysis B: Environmental
  [SJR: 2.322]   [H-I: 158]   [6 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0926-3373
   Published by Elsevier Homepage  [3032 journals]
  • Enhanced photocatalytic conversion of greenhouse gas CO2 into solar fuels
           over g-C3N4 nanotubes with decorated transparent ZIF-8 nanoclusters
    • Authors: Shengwei Liu; Feng Chen; Sitan Li; Xingxing Peng; Ya Xiong
      Pages: 1 - 10
      Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Shengwei Liu, Feng Chen, Sitan Li, Xingxing Peng, Ya Xiong
      The atmospheric concentration of CO2 as the dominant greenhouse gas continues to rise and has become a global environmental issue. Photocatalytic CO2 reduction into solar fuels has been regarded as an ideal solution to reduce CO2 emissions and to use solar energy. Graphitic carbon nitride (g-C3N4) is one of the most promising visible-light-driven photocatalysts for CO2 reduction. Unfortunately, the CO2 reduction performance of g-C3N4 based photocatalyst is normally limited by the inferior charge separation ability and limited CO2 adsorption capacity. In this study, two cooperative strategies, that is, combined host nanostructural design and surface guest grafting, are adopted to overcome the aforementioned drawbacks. Specifically, holey graphitic carbon nitride (g-C3N4) nanotubes were firstly fabricated to modify the light-harvesting ability, the redox potential as well as the charge separation efficiency. And then, the as-prepared tubular g-C3N4 was decorated with suitable amount of transparent zeolitic imidazolate framework-8 (ZIF-8) nanoclusters to further increase CO2 capture capacity without sacrifice of light absorption capacity. Because of the cooperative effects of nanostructural design and surface grafting, the optimized ZIF-8 modified tubular g-C3N4 photocatalysts exhibit a great enhancement in photocatalytic CH3OH production efficiency by more than 3 times, relative to the bulk g-C3N4 (BCN) photocatalyst synthesized by conventional pyrolysis of melamine. This work will enlighten a promising strategy to construct efficient photocatalyst for greenhouse gas CO2 resourcing, by taking advantage of the cooperative effects of semiconductor nanostructures and surface metal-organic framework grafters.
      Graphical abstract image

      PubDate: 2017-04-18T03:34:09Z
      DOI: 10.1016/j.apcatb.2017.04.009
      Issue No: Vol. 211 (2017)
  • Effect of core@shell (Au@Ag) nanostructure on surface plasmon-induced
           photocatalytic activity under visible light irradiation
    • Authors: Sunao Kamimura; Shinpei Yamashita; Shungo Abe; Toshiki Tsubota; Teruhisa Ohno
      Pages: 11 - 17
      Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Sunao Kamimura, Shinpei Yamashita, Shungo Abe, Toshiki Tsubota, Teruhisa Ohno
      We prepared Au-Ag nanoparticles (NPs) with two different morphologies over SrTiO3 to investigate the effect of composite nanostructure on surface plasmon-induced photocatalytic activity; core@shell (Au@Ag) NPs were synthesized by a multi-step citric reduction method, and Au-Ag bimetallic NPs were prepared by a photo-reduction method. (Au@Ag)/SrTiO3 and Au-Ag/SrTiO3 showed strong photoabsorption in the visible light response due to a localized surface plasmon resonance (LSPR) of Ag. Moreover, they could oxidize 2-propanol to acetone and CO2 under visible light irradiation (440<λ<800nm). From a comparison of action spectra for acetone evolution and the Kubelka-Munk function, it was confirmed that photocatalytic activities of (Au@Ag)/SrTiO3 and Au-Ag/SrTiO3 were induced by photoabsorption based on LSPR excitation of Ag. Interestingly, the rate of acetone evolution over (Au@Ag)/SrTiO3 was 1.5-times higher than that of over Au-Ag/SrTiO3, suggesting that the core@shell (Au@Ag) nanostructure contributes to the efficient surface plasmon-induced photocatalytic activity.
      Graphical abstract image

      PubDate: 2017-04-18T03:34:09Z
      DOI: 10.1016/j.apcatb.2017.04.028
      Issue No: Vol. 211 (2017)
  • Exploring pretreatment effects in Co/SiO2 Fischer-Tropsch catalysts:
           Different oxidizing gases applied to oxidation-reduction process
    • Authors: Jian Cai; Feng Jiang; Xiaohao Liu
      Pages: 1 - 13
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Jian Cai, Feng Jiang, Xiaohao Liu
      The influence of reduction-oxidation-reduction (ROR) pretreatment on 20% Co/SiO2 has been investigated using different oxidizing gases including water vapor and oxygen in the oxidation step. In this study, the evolution concerning the SiO2 structure and the cobalt phase and morphology is clearly elucidated at each step of reduction, oxidation and subsequent re-reduction. It is demonstrated that ROR treatment using both oxygen and water vapor decreases the average cobalt particle size. However, the catalytic performance affected in FTS is considerably different. ROR treatment in oxygen results in an increase in catalytic activity. In contrast, the water vapor applied in oxidation step obviously deactivates cobalt catalyst and enhances selectivity of methane. The resulting deactivation is ascribed to the promoted formation of irreducible cobalt silicate through the reaction between water vapor caused surface SiOH groups and oxidized cobalt (CoO) in spite of unchanged surface area and pore structure on SiO2. The characterization data reveals that the re-dispersion of cobalt particles occurs at oxidation step rather than the re-reduction step. In addition, the results indicate that the ROR treatment reducing the cobalt particle size depends on its initial size as no re-dispersion can be observed in the case of particles smaller than about 11nm. Furthermore, the water vapor shows more effective re-dispersion in cobalt particles compared with the use of oxygen. This study provides fundamental insights into the control of catalytic activity, product selectivity, and catalyst stability over supported cobalt catalysts by understanding the evolution of catalyst structure through ROR treatment in different chemical environment.
      Graphical abstract image

      PubDate: 2017-03-28T09:08:28Z
      DOI: 10.1016/j.apcatb.2017.03.036
      Issue No: Vol. 210 (2017)
  • Probing the functionality of nanostructured MnCeOx catalysts in the carbon
           monoxide oxidation
    • Authors: Francesco Arena; Roberto Di Chio; Barbara Fazio; Claudia Espro; Leone Spiccia; Alessandra Palella; Lorenzo Spadaro
      Pages: 14 - 22
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Francesco Arena, Roberto Di Chio, Barbara Fazio, Claudia Espro, Leone Spiccia, Alessandra Palella, Lorenzo Spadaro
      The effects of cerium addition on the physico-chemical properties and CO oxidation activity of nanostructured MnCeOx catalysts (0≤cCe ≤1) have been assessed. Irrespective of the loading, cerium hinders any significant long-range crystalline order promoting surface exposure, oxide dispersion, and reducibility of composite catalysts. Noticeable structural effects and strong oxide interaction lead to different arrangement of the active MnOx phase, explaining the peculiar reactivity scale of the studied catalysts in the CO oxidation reaction. High activity, good stability, CO2 productivity values depending on the MnOx loading, and similar activation energy values in the range of 353–533K (37–47kJ/mol) uncover an unchanging reaction mechanism, irrespective of composition and temperature. Although some chemical effects at high Ce loading (χCe ≥0.5), structure-activity relationships indicate that surface MnIV centers are the active sites of bulk MnOx and composite MnCeOx catalysts.
      Graphical abstract image

      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.049
      Issue No: Vol. 210 (2017)
  • Rational design and synthesis of SnO2-encapsulated α-Fe2O3 nanocubes as a
           robust and stable photo-Fenton catalyst
    • Authors: Na Wang; Yunchen Du; Wenjie Ma; Ping Xu; Xijiang Han
      Pages: 23 - 33
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Na Wang, Yunchen Du, Wenjie Ma, Ping Xu, Xijiang Han
      In situ transformation of metal-organic frameworks (MOFs) is becoming a fascinating strategy to construct porous metal oxides with excellent performance in many fields. In this work, Prussian blue (PB) nanocubes are employed as the precursor of porous Fe2O3 to fabricate SnO2-encapsulated α-Fe2O3 (Fe2O3@SnO2) nanocubes by pre-coating Sn(OH)Cl on the surface of PB nanocubes. It is very interesting to find that SnO2 shells can not only preserve the microstructure of Fe2O3 nanocubes from high-temperature treatment, but also facilitate the phase variation from metastable γ/β-phase to stable α-phase. The thickness of SnO2 shells can be controlled by manipulating the amount of stannous chloride. When Fe2O3@SnO2 nanocubes are applied as heterogeneous photo-Fenton catalysts, they will exhibit much better catalytic efficiency for the degradation of Rhodamine B (RhB) than PB-derived Fe2O3 and commercial α-Fe2O3. The characterization results reveal that Fe2O3@SnO2 nanocubes have similar catalytic mechanism to conventional α-Fe2O3, and stable microstructure and preferable crystalline phase are primarily responsible for this significant enhancement. Some influential factors, including H2O2 concentration, catalyst dosage, pH value, and reaction temperature are investigated and analyzed in details. Moreover, Fe2O3@SnO2 nanocubes can maintain their catalytic efficiency during the repeated batch experiments. We believe Fe2O3@SnO2 nanocubes can be a new kind of high-performance green heterogeneous catalyst for the degradation of organic pollutants, and this study may provide a new idea to upgrade the performance of some conventional catalysts by rational design in the future.
      Graphical abstract image

      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.037
      Issue No: Vol. 210 (2017)
  • Influence of preparation method on dispersion of cobalt spinel over
           alumina extrudates and the catalyst deN2O activity
    • Authors: Gabriela Grzybek; Sylwia Wójcik; Klaudia Ciura; Joanna Gryboś; Paulina Indyka; Marcin Oszajca; Paweł Stelmachowski; Stefan Witkowski; Marek Inger; Marcin Wilk; Andrzej Kotarba; Zbigniew Sojka
      Pages: 34 - 44
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Gabriela Grzybek, Sylwia Wójcik, Klaudia Ciura, Joanna Gryboś, Paulina Indyka, Marcin Oszajca, Paweł Stelmachowski, Stefan Witkowski, Marek Inger, Marcin Wilk, Andrzej Kotarba, Zbigniew Sojka
      A series of supported catalysts of the Co3O4 spinel active phase dispersed over alumina extrudates (9×25mm) was prepared by several methods (incipient wetness impregnation with Co(NO3)2 and CoCl2, with glycerol-assisted impregnation with Co(NO3)2, combustion synthesis, and two variants of spray deposition with Co(NO3)2 on pristine and ammonia soaked extrudates). The catalysts were characterized by XRF, XRD, RS, UV–vis, SEM/TEM/EDX, and their catalytic deN2O activity was investigated in the temperature programmed surface reaction (TPSR) mode. The relation between the spinel active phase particle size and its radial dispersion over the alumina extrudate and the deN2O activity was revealed and quantified. For the assessment of the active phase utilization, the N2O concentration profile across the extrudates was calculated using Thiele modulus and compared with the radial distribution of the spinel. It was shown that the dispersion of spinel active phase exhibits optimal profile when the sample is obtained in the presence of the organic components of the precursor mixture (glycerol or urea). The obtained results were discussed in the context of practical implications for the development of an efficient, low-cost catalyst for the N2O abatement.
      Graphical abstract image

      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.053
      Issue No: Vol. 210 (2017)
  • Peculiar synergetic effect of MoS2 quantum dots and graphene on
           Metal-Organic Frameworks for photocatalytic hydrogen evolution
    • Authors: Xuqiang Hao; Zhiliang Jin; Hao Yang; Gongxuan Lu; Yingpu Bi
      Pages: 45 - 56
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Xuqiang Hao, Zhiliang Jin, Hao Yang, Gongxuan Lu, Yingpu Bi
      Special enhanced synergetic effect of MoS2 quantum dots (MoS2 QDs) and graphene on metal-organic frameworks for photocatalytic hydrogen evolution is obtained here. The photocatalytic activity of H2 evolution reach 186.37μmol over the EY-sensitized 5 wt% MoS2 QDs/UiO-66-NH2/G irradiated under visible light irradiation (λ≥420nm) in the first 3h, and the apparent quantum efficiency (AQE) is 40.5% at 430nm. The synergistic effect between MoS2 QDs and graphene together with UiO-66-NH2 is corroborated by photo-luminescence spectra, electro-chemical and photo-electro-chemical experiments. It demonstrate that the charge separation and the electrons transfer are more efficient with the aid of the MoS2 QDs and graphene. MoS2 QDs might be a potential photocatalyst for design new type of catalysts in photocatalysis proton reduction.
      Graphical abstract image

      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.057
      Issue No: Vol. 210 (2017)
  • 3D interconnected hierarchically porous N-doped carbon with NH3 activation
           for efficient oxygen reduction reaction
    • Authors: Yi Wang; Hanyu Liu; Kun Wang; Shuqin Song; Panagiotis Tsiakaras
      Pages: 57 - 66
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Yi Wang, Hanyu Liu, Kun Wang, Shuqin Song, Panagiotis Tsiakaras
      In the present work, a novel metal-free ORR electrocatalyst, with large specific surface area (2600m2 g−1), high content of N dopants (3.12 at.%) and 3D cross-linking hierarchically porous structure (abbreviated as LHNHPC) is readily prepared by using a modified classical carbon-aerogel method with NH3 as the activating agent. Compared with benchmark Pt/C catalyst, it is found that, LHNHPC exhibits similar electrocatalytic activity towards oxygen reduction reaction (ORR), superior durability and excellent methanol tolerance in basic media. The above electrochemical properties of LHNHPC are mainly attributed to the synergistic contribution of its unique hierarchical pore structure, the rich N doping and the large surface area. It can be anticipated that the proposed two-step process could be used for mass production of metal free electrocatalysts for a wide range of electrochemical devices including fuel cells and metal-air batteries.
      Graphical abstract image

      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.054
      Issue No: Vol. 210 (2017)
  • Efficient Co@CoO core-shell nanocrystals as catalysts for
           visible-light-driven water oxidation
    • Authors: Zheng Wan; Qian Xu; Hui Li; Yi Zhang; Yong Ding; Jide Wang
      Pages: 67 - 76
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Zheng Wan, Qian Xu, Hui Li, Yi Zhang, Yong Ding, Jide Wang
      This paper introduces the first attempt of using well organized Co@CoO core-shell nanocrystals as an alternative toward noble metal catalysts for photocatalytic water splitting reactions. In this work, four kinds of stable magnetic Co@CoO core-shell nanocrystals were fabricated through a one-pot toluene-water two-phase interfacial reaction with oleic acid as a surfactant. The size and shape of the as-prepared crystals can be carefully adjusted through dynamically coating the closely packed monolayer of coordinating ligand onto the growing crystals. It is notable that spherical pine-nut-like hierarchical assemblies of Co@CoO core-shell nanoplates exhibit excellent photocatalytic activity (the maximum value of O2 yield is over 96%). Even after the sixth run, the high catalytic activity of the recovered Co@CoO core-shell nanoplates remained.
      Graphical abstract image

      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.056
      Issue No: Vol. 210 (2017)
  • Novel 3DOM-SrTiO3/Ag/Ag3PO4 ternary Z-scheme photocatalysts with
           remarkably improved activity and durability for contaminant degradation
    • Authors: Chenxi Zhang; Kai Yu; Yajun Feng; Yue Chang; Ting Yang; Ying Xuan; Da Lei; Lan-Lan Lou; Shuangxi Liu
      Pages: 77 - 87
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Chenxi Zhang, Kai Yu, Yajun Feng, Yue Chang, Ting Yang, Ying Xuan, Da Lei, Lan-Lan Lou, Shuangxi Liu
      The novel visible-light-driven 3DOM-SrTiO3/Ag/Ag3PO4 ternary composites were fabricated and used as photocatalysts in the degradation of organic contaminants, including RhB, phenol, and MB. Through the XRD, SEM, TEM, DR UV–vis, XPS, PL spectroscopy, N2 sorption, and photoelectrochemical measurement, the obtained 3DOM-SrTiO3/Ag/Ag3PO4 ternary composites were well characterized. The effects of SrTiO3:Ag3PO4 molar ratio and stop-bands of 3DOM-SrTiO3 on the catalytic performance were systemically investigated. 3DOM-SrTiO3/Ag/Ag3PO4 ternary composite photocatalysts exhibited notably enhanced activity compared with single 3DOM-SrTiO3 and Ag3PO4 catalyst. Among these ternary photocatalysts, S35A65(300) exhibited the most excellent photocatalytic performance under visible light irradiation, which could be mainly attributed to synergy effect of the notably improved separate efficiency of photogenerated electron-hole pairs and the suitable stop-bands of 3DOM-SrTiO3(300) material. Although the gradually reduced activity in cycling tests was obtained over S35A65(300) under visible light irradiation, an excellent durability could be achieved for S35A65(300) under UV–vis light irradiation. No obvious loss in photocatalytic efficiency was observed after six cycles for RhB degradation. The notably improved enhanced durability of 3DOM-SrTiO3/Ag/Ag3PO4 ternary composites under UV–vis light irradiation could be mainly attributed to the Z-scheme mechanism of this ternary composite photocatalyst.
      Graphical abstract image

      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.058
      Issue No: Vol. 210 (2017)
  • Photodegradation of sulfonamides by g-C3N4 under visible light
           irradiation: Effectiveness, mechanism and pathways
    • Authors: Yali Song; Jiayu Tian; Shanshan Gao; Penghui Shao; Jingyao Qi; Fuyi Cui
      Pages: 88 - 96
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Yali Song, Jiayu Tian, Shanshan Gao, Penghui Shao, Jingyao Qi, Fuyi Cui
      For the first time, the photocatalytic degradation of sulfamethoxazole (SMX), sulfisoxazole (SSX), sulfadiazine (SDZ), sulfamerazine (SMZ) by g-C3N4 under visible light irradiation was investigated. Results revealed that compared to photolysis, the photocatalytic degradation efficiencies of the four sulfonamides were significantly enhanced with the addition of g-C3N4, and more than 90% of photodegradation removal was obtained. The effects of typical water quality parameters, including solution pH, bicarbonate ion and humic acid, on the photodegradation process were discussed. It was found that although the photodegradation of the four sulfonamides exhibited different trends under the variation of the water quality parameters, an excellent photocatalytic removal could always be achieved, illustrating the robustness and effectiveness of the g-C3N4 photodegradation process. The ESR measurements showed that both OH and O2 − were produced in the photocatalytic process of g-C3N4 under visible light irradiation. And trapping experiments confirmed that O2 − and holes played a significant role in the photodegradation of SMX, SDZ and SMZ; but holes and OH were the main oxidative species for SSX degradation. Finally, according to the oxidation products detected by ultra-high performance liquid chromatography-tandem mass spectrometric (UPLC/MS/MS), the degradation pathways of the four sulfonamides were proposed and compared. It was found that there were some common pathways shared by the different sulfonamides, such as cleavage of S-N bond and hydroxylation of the benzene ring (the main degradation pathways for SSX). More importantly, some specific photodegradation pathways were also identified: (1) the nitration of amino group on the benzene ring occurred for SMX, SDZ and SMZ (the main degradation pathway for SMX, SDZ and SMZ), but not for SSX; (2) the bond cleavage between benzene ring and S occurred only in degradation of SSX; and (3) the carboxylation of the methyl group occurred only in degradation of SMZ.
      Graphical abstract image

      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.059
      Issue No: Vol. 210 (2017)
  • A simple combustion method for the synthesis of multi-functional ZrO2/CuO
           nanocomposites: Excellent performance as Sunlight photocatalysts and
           enhanced latent fingerprint detection
    • Authors: L. Renuka; K.S. Anantharaju; Y.S. Vidya; H.P. Nagaswarupa; S.C. Prashantha; S.C. Sharma; H. Nagabhushana; G.P. Darshan
      Pages: 97 - 115
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): L. Renuka, K.S. Anantharaju, Y.S. Vidya, H.P. Nagaswarupa, S.C. Prashantha, S.C. Sharma, H. Nagabhushana, G.P. Darshan
      A facile solution combustion synthesis has been adopted to synthesize ZrO2/CuO nanocomposite oxides (NCO’s) by utilizing Oxalyl dihydrazide (ODH) as fuel. The X-ray diffraction patterns and TEM analysis reveals the presence of cubic ZrO2 and CuO in ZrO2/CuO NCO’s. The NCO’s synthesized by simple, fast, highly sensitive and low-cost method is found to be an alternate to traditional luminescent powders for the detection and enhancement of finger marks in a broad range of surfaces. The photoluminescence analysis indicates that the present NCO is an effective blue component in display applications. The synthesized ZrO2/CuO (2:1) composite exhibited excellent photocatalytic activity towards the degradation of various dyes under Sunlight. In particular, Indigo carmine dye was chosen to explore the photocatalytic performance of prepared NCO’s under Sunlight illumination. It was found that ZrO2:CuO (2:1) NCO showed enhanced photocatalytic activity of 97% which was found to be 3.3 times 2.4 times and 1.5 times higher than that of pure ZrO2, CuO and commercial P25. This can be mainly attributed to the balance between the parameters, band gap, nature of morphology, crystallite size, defects and surface area which causes a slow electron-hole pair recombination rate with fast electron transfer ability. It opens new window to use this simple method to synthesize multifunctional character ZrO2-based composite materials in the area of photocatalysis particularly waste water treatment, display applications as well as a labeling agent to enhance latent fingerprints.
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      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.055
      Issue No: Vol. 210 (2017)
  • Deactivation mechanism and regeneration of carbon nanocomposite catalyst
           for acetylene hydrochlorination
    • Authors: Xingyun Li; Pan Li; Xiulian Pan; Hao Ma; Xinhe Bao
      Pages: 116 - 120
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Xingyun Li, Pan Li, Xiulian Pan, Hao Ma, Xinhe Bao
      Acetylene hydrochlorination is an important coal-based technology for production of vinyl chloride, the monomer of one of the world mostly used plastics. Despite of the great potentials demonstrated for carbon-based catalysts to replace the toxic mercury chloride, the stability and the deactivation mechanism are rarely discussed, which is essential for real applications. Herein, we present a detailed study on the deactivation mechanism of nitrogen doped carbon based catalyst in acetylene hydrochlorination. The results show that the deactivation was likely caused by the carbon-like deposition over the catalyst, which can be regenerated with high temperature NH3 treatment.
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      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.046
      Issue No: Vol. 210 (2017)
  • Carbon nanotube supported PdAg nanoparticles for electrocatalytic
           oxidation of glycerol in anion exchange membrane fuel cells
    • Authors: Neeva Benipal; Ji Qi; Qi Liu; Wenzhen Li
      Pages: 121 - 130
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Neeva Benipal, Ji Qi, Qi Liu, Wenzhen Li
      Electro-oxidation of alcohol is the key reaction occurring at the anode of a direct alcohol fuel cell (DAFC), in which both reaction kinetics (rate) and selectivity (to deep oxidation products) need improvement to obtain higher power density and fuel utilization for a more efficient DAFC. We recently found that a PdAg bimetallic nanoparticle catalyst is more efficient than Pd for alcohol oxidation: Pd can facilitate deprotonation of alcohol in a base electrolyte, while Ag can promote intermediate aldehyde oxidation and cleavage of C-C bond of C3 species to C2 species. Therefore, a combination of the two active sites (Pd and Ag) with two different functions, can simultaneously improve the reaction rates and deeper oxidation products of alcohols (Applied Catalysis B, 2016, 199, 494). In this continuing work, Pd, Ag mono, and bimetallic nanoparticles supported on carbon nanotubes (Ag/CNT, Pd/CNT, Pd1Ag1/CNT, and Pd1Ag3/CNT) were prepared using an aqueous-phase reduction method; they served as working catalysts for studying electrocatalytic oxidation of glycerol in an anion-exchange membrane-based direct glycerol fuel cell. Combined XRD, TEM, and HAADF-STEM analyses performed to fully characterize as-prepared catalysts suggested that they have small particle sizes: 2.0nm for Pd/CNT, 2.3nm for PdAg/CNT, 2.4nm for PdAg3/CNT, and 13.9nm for Ag/CNT. XPS further shows that alloying with Ag results in more metal state Pd presented on the surface, and this may be related to their higher direct glycerol fuel cell (DGFC) performances. Single DGFC performance and product analysis results show that PdAg bimetallic nanoparticles can not only improve the glycerol reaction rate so that higher power output can be achieved, but also facilitate deep oxidation of glycerol so that a higher faradaic efficiency and fuel utilization can be achieved along with optimal reaction conditions (increased base-to-fuel ratio). Half-cell electrocatalytic activity measurement and single fuel cell product analysis of different glycerol oxidation intermediates, including C3: glycerate, tartronate, mesoxalate, and lactate; C2: glycolate and oxalate, over PdAg/CNT catalyst was further conducted and produced deeper insight into the synergistic effects and reaction pathways of bimetallic PdAg catalysts in glycerol electrocatalytic oxidation.
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      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.02.082
      Issue No: Vol. 210 (2017)
  • CO2 capture and photocatalytic reduction using bifunctional TiO2/MOF
           nanocomposites under UV–vis irradiation
    • Authors: Angus Crake; Konstantinos C. Christoforidis; Andreas Kafizas; Spyridon Zafeiratos; Camille Petit
      Pages: 131 - 140
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Angus Crake, Konstantinos C. Christoforidis, Andreas Kafizas, Spyridon Zafeiratos, Camille Petit
      TiO2 nanosheets and metal-organic framework (NH2-UiO-66) were effectively coupled via an in‐situ growth strategy to form bifunctional materials for the combined capture and photocatalytic reduction of CO2 under UV–vis light irradiation. This was done to take advantage of the high CO2 adsorption capacity of the MOF and the photocatalytic properties of pre-formed TiO2 nanosheets in a single material. The prepared materials were thoroughly characterized using a variety of techniques. They were subsequently tested for CO2 adsorption and CO2 photocatalytic reduction using a heterogeneous gas/solid set-up to imitate both CO2 capture and fixation in a single process. The adopted synthesis process allowed the development of a tight interaction between TiO2 and NH2-UiO-66 forming a heterojunction, while maintaining both the high CO2 uptake and porosity of NH2-UiO-66. The nanocomposites were proven durable and significantly more efficient in reducing CO2 to CO than their single components. Photocatalytic activity was greatly affected by the nanocomposites composition with the optimum TiO2 content doubling the CO evolution rate compared with the pure TiO2. The improved photoactivity was assigned to the enhanced abundance of long lived charge carriers, as revealed by transient absorption spectroscopy (TAS). This most likely occurred due to the effective charge transfer via interface. A possible mechanism is discussed on the basis of the combined catalytic, spectroscopic and CO2 adsorption results.
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      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.039
      Issue No: Vol. 210 (2017)
  • CeO2-x platelet from monometallic cerium layered double hydroxides and its
           photocatalytic reduction of CO2
    • Authors: Ting Ye; Weimin Huang; Liming Zeng; Mengli Li; Jianlin Shi
      Pages: 141 - 148
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Ting Ye, Weimin Huang, Liming Zeng, Mengli Li, Jianlin Shi
      Monometallic cerium layered double hydroxides (MCe-LDHs) were successfully synthesized for the first time through a simple approach. XRD, TEM, SEM, XPS, FT-IR, TG-DSC techniques and UV–vis diffuse reflectance spectroscopy were used to characterize the samples. The obtained MCe-LDHs showed typical layered structure composing of quasi-hexagonal platelets with side length of about 2μm and thickness about tens of nanometers, and preserved its platelet morphology after heat treatment at up to 800°C. Our study also revealed that the heat-treatments at different temperatures could be employed to tune the concentration ratio of Ce3+/Ce4+ and the surface area of those cerium oxide platelets, both of which play a key role in the photocatalytic activity towards photoreduction of CO2.
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      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.051
      Issue No: Vol. 210 (2017)
  • Efficient photocatalytic hydrogen production over La/Rh co-doped
           Ruddlesden-Popper compound Sr2TiO4
    • Authors: Xiaoqin Sun; Xiaoxiang Xu
      Pages: 149 - 159
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Xiaoqin Sun, Xiaoxiang Xu
      Layered semiconductor compounds often exhibit intriguing properties for photocatalytic water splitting, probably correlated with their peculiar crystal structures that facilitate charge separations. In this work, we perform an investigation on the layered Ruddlesden-Popper compound Sr2TiO4 and its La/Rh co-doped counterparts for photocatalytic hydrogen production from water. Their crystal structures, optical absorption and other physicochemical properties have been systematically explored. Our results suggest that La/Rh can be successfully incorporated into Sr2TiO4 with layered crystal structure maintained. The use of polymerized-complex method for sample synthesis significantly reduces the calcination temperature as low as 900°C. La/Rh serves as efficient dopants for extending the light absorbance of Sr2TiO4 as far as 550nm. Photocatalytic hydrogen productions are also considerably improved after La/Rh co-doping under both full range (λ≥250nm) and visible light irradiation (λ≥420nm). An optimal doping level is reached at 3% (Sr1.97La0.03Ti0.97Rh0.03O4) which gives the highest average hydrogen production rate ∼100μmol/h and ∼40μmol/h under full range (λ≥250nm) and visible light irradiation (λ≥420nm), corresponding to apparent quantum efficiency ∼1.27% and ∼1.18%, respectively. Photoelectrochemical analysis reveals that charge separation and electron lifetime strongly depends on the level of La/Rh co-doping. Mott-Schottky analysis and theoretical calculations indicate that the improved light absorption of La/Rh co-doped Sr2TiO4 stems from the formation of new valence band with Rh 4d character which uplifts the valence band edge of Sr2TiO4.
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      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.063
      Issue No: Vol. 210 (2017)
  • MoS2 quantum dots-interspersed Bi2WO6 heterostructures for visible
           light-induced detoxification and disinfection
    • Authors: Xiangchao Meng; Zizhen Li; Haoming Zeng; Jie Chen; Zisheng Zhang
      Pages: 160 - 172
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Xiangchao Meng, Zizhen Li, Haoming Zeng, Jie Chen, Zisheng Zhang
      MoS2 Quantum dots-interspersed Bi2WO6 heterostructure is fabricated for photocatalytic applications for the first time. It exhibits enhanced visible light-driven photocatalytic detoxification and disinfection in wastewater compared to bare Bi2WO6 and MoS2. MoS2 quantum dots as a co-catalyst applied in photocatalysis oxidation possesses multiple merits: (1) noble-metal-free; (2) high mobility of photogenerated charge carriers; (3) high adsorption capacity and (4) improved capture capacity of visible light photons. Electron-hole separation rate which is critical for an efficient photocatalysis is greatly improved via the built-in electric field of p-n heterostructure and the quantum dots interspersed on the surface. This work shed a light on loading MoS2 quantum dots as a co-catalyst on a support aiming to significantly improve its photocatalytic performance in organic pollutants degradation and bacteria inactivation.
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      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.02.083
      Issue No: Vol. 210 (2017)
  • Fish-scale structured g-C3N4 nanosheet with unusual spatial electron
           transfer property for high-efficiency photocatalytic hydrogen evolution
    • Authors: Bo Lin; Hua An; Xiaoqing Yan; Tianxi Zhang; Jinjia Wei; Guidong Yang
      Pages: 173 - 183
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Bo Lin, Hua An, Xiaoqing Yan, Tianxi Zhang, Jinjia Wei, Guidong Yang
      Grafing the structures in nature onto g-C3N4 is an interesting and fascinating protocol to highly optimize its performances. Herein, a novel opened-up fish-scale structured g-C3N4 nanosheet has been synthesized via a simple one-step solvothermal method for photocatalytic hydrogen evolution. The unique fish-scale structure endows g-C3N4 with unusual spatial electron transfer property, which means that the photogenerated electrons selectively migrate along the flat direction to the edges of fish-scale flakes. This property well reveals the transfer path of photogenerated charges and the origin of high charge separation efficiency in photocatalytic reaction, thus yielding a remarkable catalytic activity (a hydrogen-evolution rate of 1316.35 μ molh−1 g−1), nearly 20 and 2.93 times higher than that of bulk g-C3N4 and exfoliated g-C3N4 nanosheet. Besides, the fish-scale structured g-C3N4 also owns a superior durability and stability, indicating an outstanding potential application in solar fuel production. The research results would provide a platform for the design and construction of high-performance photocatalysts with highly-efficient charge separation.
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      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.066
      Issue No: Vol. 210 (2017)
  • Fabrication of TiO2 hollow microspheres assembly from nanosheets
           (TiO2-HMSs-NSs) with enhanced photoelectric conversion efficiency in DSSCs
           and photocatalytic activity
    • Authors: Ruiwen Yang; Jinghua Cai; Kangle Lv; Xiaofeng Wu; Wenguang Wang; Zhihua Xu; Mei Li; Qin Li; Weiqing Xu
      Pages: 184 - 193
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Ruiwen Yang, Jinghua Cai, Kangle Lv, Xiaofeng Wu, Wenguang Wang, Zhihua Xu, Mei Li, Qin Li, Weiqing Xu
      Fabrication of TiO2 hollow microspheres (TiO2-HMSs) with complex structure is of great importance but remains a great challenge. In this paper, hierarchical TiO2 hollow microspheres assembly from nanosheets (TiO2-HMSs-NSs) were prepared by hydrothermal treatment of TiO2-HMSs precursor in NaOH solution and followed by acid wash and calcination. The effect of hydrothermal reaction time on the structure and photoelectric conversion performances of TiO2-HMSs-NSs film solar cells was systematically studied. It was found that both the BET surface area and photocatalytic activity of TiO2-HMSs-NSs, in photocatalytic degradation of Brilliant Red X-3B dye, are positively related to the hydrothermal reaction time (from 0 to 3h). The BET specific area of TiO2-HMSs-NSs steady increase from 21m2 g−1 of TiO2-HMSs precursor (H0) to 184m2 g−1 (H3), improved by a factor of 8.76, while the photocatalytic activity of H3 increased 7.50 times when compared with that of H0 sample. The highest photoelectric conversion efficiency (5.97%) of TiO2-HMSs-NSs film solar cell was obtained for H2 sample, exceeding that of TiO2-HMSs precursor (H0) based film solar cell (3.75%) with the same film thickness by a factor of 1.6. The improved photoelectric conversion efficiency of TiO2-HMSs-NSs based solar cell was attributed to the unique hierarchical hollow structure, which results in a good contact between TiO2 and FTO glass, enlarged pore volume, enhanced adsorption to sensitizer and improved light scattering ability.
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      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.064
      Issue No: Vol. 210 (2017)
  • Carbon nitride coupled with CdS-TiO2 nanodots as 2D/0D ternary composite
           with enhanced photocatalytic H2 evolution: A novel efficient three-level
           electron transfer process
    • Authors: Zhifeng Jiang; Kun Qian; Chengzhang Zhu; Hongli Sun; Weiming Wan; Jimin Xie; Huaming Li; Po Keung Wong; Shouqi Yuan
      Pages: 194 - 204
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Zhifeng Jiang, Kun Qian, Chengzhang Zhu, Hongli Sun, Weiming Wan, Jimin Xie, Huaming Li, Po Keung Wong, Shouqi Yuan
      Photocatalytic H2 evolution from water splitting requires an efficient photocatalyst with excellent charge separation ability and broad visible-light adsorption region. 0D CdS-TiO2 nanodots (NDs) were successfully decorated on the 2D g-C3N4 sheets via an epitaxial growth process. The as-synthesized ternary composite of CdS-TiO2@g-C3N4 exhibits enhanced visible-light-driven photocatalytic H2 evolution activity, as compared to the binary composites and their single components, which is about 6.7 and 11.2 times higher than those of single CdS and g-C3N4, respectively. Moreover, the as-obtained ternary composite has an external quantum efficiency (EQE) of 11.9% at 420nm, implying the high utilization efficiency of photo-induced charges. In addition, the superior photostability can be achieved by this coupling method. The enhanced photocatalytic activity was attributed to the efficient charge separation originated from the three-level electron transfer system, the matched energy level positions, the abundant adsorption sites and active sites (0D/2D structure) and the synergistic effect among CdS, TiO2 and g-C3N4. The work present here demonstrated that the construction of this three-level electron transfer system is an effective strategy to design more efficient ternary materials toward solar energy conversion (like H2 production and CO2 reduction).
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      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.069
      Issue No: Vol. 210 (2017)
  • Ni3(C3N3S3)2 coordination polymer as a novel broad spectrum-driven
           photocatalyst for water splitting into hydrogen
    • Authors: Feng Guo; Weilong Shi; Sijie Guo; Weisheng Guan; Yanhong Liu; Hui Huang; Yang Liu; Zhenhui Kang
      Pages: 205 - 211
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Feng Guo, Weilong Shi, Sijie Guo, Weisheng Guan, Yanhong Liu, Hui Huang, Yang Liu, Zhenhui Kang
      Sparked by the increasing energy crisis, much research has been focused on seeking board spectrum-driven photocatalysts for water splitting. Herein, the Ni3(C3N3S3)2 coordination polymer was firstly synthesized by a simple wet-chemical method, as a novel board spectrum-driven photocatalyst for water splitting. The as-prepared Ni3(C3N3S3)2 exhibited excellent photocatcalytic H2-producing activity from the half-reaction of water splitting without the help of any sacrificial agents or cocatalysts, and the amounts of H2 production are 65.3, 53.9 and 16.3μmol corresponding to UV (λ<400nm), visible (400≤λ≤760nm) and near-infrared (λ>760nm) irradiation after 24h, respectively. Another valuable finding is that after adding triethanolamine as a sacrificial donor, the average H2 evolution efficiencies on Ni3(C3N3S3)2 were efficaciously increased by around 2-fold with the H2 production value of 112.6, 93.3 and 30.1μmol for 24h under the UV light, visible light and near-infrared light exposure, respectively. More importantly, the stability of Ni3(C3N3S3)2 was effectively improved by means of triethanolamine. The results facilitate the increasing attention of narrow band gap non-noble metal coordination polymers treated as board spectrum-driven photocatalysts for expanding the utilization of solar light.
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      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.062
      Issue No: Vol. 210 (2017)
  • Hydrogen production from formic acid dehydrogenation over Pd/C catalysts:
           Effect of metal and support properties on the catalytic performance
    • Authors: Hyo-jin Jeon; Young-Min Chung
      Pages: 212 - 222
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Hyo-jin Jeon, Young-Min Chung
      While formic acid dehydrogenation has become one of the most promising strategies for hydrogen storage, the crucial factors for realizing an efficient catalyst remain controversial. In this study, a range of Pd/C catalysts were systematically prepared by adopting either diverse metal deposition methods or different acid treatments, and the resulting catalysts were used for formic acid dehydrogenation under ambient conditions without additives. The volcano-type dependence of the activity on the Pd particle size, rate enhancement over Pd with smaller [111]/[200] ratios, and superior activity of Pd0 or Pd0/Pd(OH)2 mixture to Pd2+ clearly indicate that not only the particle size but also the surface structure or electronic states of active metal would be of prime importance to promote the reaction. Moreover, another volcano relation between the activity and the pH of a reaction solution determined by the functional groups of an acid-treated support obviously suggests that the catalytic activity is very sensitive to pH, and that a neutral reaction solution is preferred to maximize the catalytic performance. The unprecedented critical effect of a support on the catalytic performance may be rationalized in terms of two factors: (i) recombination of the formate ion with a proton and/or delay of formic acid deprotonation by excess protons in an acidic solution; (ii) competitive adsorption between the formate and hydroxyl ions in a basic solution. Therefore, tuning the nature of a support to achieve a balance between the two competitive factors is important to enhance the catalytic performance.
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      PubDate: 2017-04-04T01:49:33Z
      DOI: 10.1016/j.apcatb.2017.03.070
      Issue No: Vol. 210 (2017)
  • Synergistic effect between copper and cerium on the performance of
           Cux-Ce0.5-x-Zr0.5 (x=0.1–0.5) oxides catalysts for selective catalytic
           reduction of NO with ammonia
    • Authors: Sher Ali; Liqiang Chen; Fulong Yuan; Rui Li; Tianrui Zhang; Syed ul Hasnain Bakhtiar; Xuesong Leng; Xiaoyu Niu; Yujun Zhu
      Pages: 223 - 234
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Sher Ali, Liqiang Chen, Fulong Yuan, Rui Li, Tianrui Zhang, Syed ul Hasnain Bakhtiar, Xuesong Leng, Xiaoyu Niu, Yujun Zhu
      A series of Cu x -Ce0.5-x -Zr0.5 oxides catalysts with different Cu/Ce ratio were synthesized by citric acid method. The catalysts were characterized by XRD, BET surface area, H2-TPR, NH3-TPD, NO-TPD, XPS and in-situ DRIFTS. The synergistic effect between copper and cerium on the catalytic performance of Cu x -Ce0.5-x -Zr0.5 for selective catalytic reduction of NO with ammonia was investigated. It was found that the Cu0.2-Ce0.3-Zr0.5 catalyst show the excellent SCR activity, N2 selectivity and H2O/SO2 durability in a low temperature range of 150–270°C even at high gas hourly space velocity of 84,000h−1. The strong interaction leads to the improvement of the acidity and the increase in the amount of active oxygen species (oxygen vacancy), which are responsible for the higher activity at low temperatures. The SCR reaction process over Cu0.2-Ce0.3-Zr0.5 was also examined using in-situ DRIFTS. The DRIFTS results indicate that abundant ionic NH4 + (Brønsted acid sites), coordinated NH3 on the Lewis acid sites, as well as highly active monodentate nitrate and bridging nitrate species were the key intermediates in the SCR reaction.
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      PubDate: 2017-04-11T02:08:04Z
      DOI: 10.1016/j.apcatb.2017.03.065
      Issue No: Vol. 210 (2017)
  • Review of recent trends in photoelectrocatalytic conversion of solar
           energy to electricity and hydrogen
    • Authors: Panagiotis Lianos
      Pages: 235 - 254
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Panagiotis Lianos
      This work is a review of the recent trends in the photoelectrocatalytic conversion of solar energy into electricity or hydrogen. It focuses on photocatalytic fuel cells and photoelectrocatalytic water splitting systems and presents both the basic principles and the design of devices. It includes a broad review of materials employed for the construction of photoanodes, photocathodes and tandem cells and highlights the related research fields which are expected to be of interest in the near future. The review is intended to become a basic manual for new adepts to the field and at the same time a handy reference to experienced researchers.
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      PubDate: 2017-04-11T02:08:04Z
      DOI: 10.1016/j.apcatb.2017.03.067
      Issue No: Vol. 210 (2017)
  • Halo-organic pollutants: The effect of an electrical bias on their
           decomposition mechanism on porous iron electrodes
    • Authors: Eitan J.C. Borojovich; Ronen Bar-Ziv; Olga Oster-Golberg; Hen Sebbag; Michael Zinigrad; Dan Meyerstein; Tomer Zidki
      Pages: 255 - 262
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Eitan J.C. Borojovich, Ronen Bar-Ziv, Olga Oster-Golberg, Hen Sebbag, Michael Zinigrad, Dan Meyerstein, Tomer Zidki
      The de-halogenation processes of CH2BrCHBrCOO− and of CH2ClCH(OH)COO− on Zero Valent Iron (ZVI) powders and porous iron electrodes were studied. The results suggest that by applying a negative voltage bias on the electrode, the composition of the products obtained is dramatically changed. Furthermore, the applied potential inhibits the passivation of the ZVI. Thus, it is recommended that the application of a negative potential to porous ZVI is desirable in batch treatment of halo-organic pollutants.
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      PubDate: 2017-04-11T02:08:04Z
      DOI: 10.1016/j.apcatb.2017.03.068
      Issue No: Vol. 210 (2017)
  • Photo enhanced methanol electrooxidation: Further insights into Pt and
           TiO2 nanoparticle contributions
    • Authors: Christopher Odetola; Liliana N. Trevani; E. Bradley Easton
      Pages: 263 - 275
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Christopher Odetola, Liliana N. Trevani, E. Bradley Easton
      Pt nanoparticles (PtNPs) were deposited on two different supports: Vulcan® XC-72R carbon (PV) and TiO2/G-PV, a TiO2/carbon composite support prepared using glucose-doped Vulcan® XC-72R carbon (G-PV). The presence of TiO2 has been shown to maximize the PtNPs specific surface area and improves the catalytic performance through Pt-metal oxide interaction. The catalytic activity of Pt/TiO2/G-PV and Pt/PV toward the methanol oxidation reaction (MOR) was investigated with and without ultraviolet-visible (UV–vis) light irradiation using different electrochemical techniques. The results show the enhancement in catalytic activity in Pt/PV under illumination (Ipeak illumination-Ipeak dark)*100/Ipeak dark ∼100%) can be attributed to a significant reduction in the charge transfer resistance (Rct) when the electrode is illuminated (635Ω (dark) vs 84Ω (illumination)) as determined by electrochemical impedance spectroscopy (EIS). The observed photo enhancement is relatively modest when compared to the Pt/TiO2/G-PV catalyst (Ipeak illumination-Ipeak dark)*100/Ipeak dark ∼171%), even though the change in the Rct (185Ω vs. 99Ω) is not as pronounced as in the Pt/PV samples. The carbon monoxide (CO) stripping results indicate that illumination aids the removal of adsorbed CO from the PtNPs surface. The remarkable enhancement on the oxidation of methanol under UV–vis illumination in the case of the Pt/TiO2/G-PV catalyst materials show the potential of these materials for applications such as disposable and portable electrochemical sensors for water analysis, mainly the determination of organic contaminants in water. Moreover, it can be a breakthrough in the development of novel photoelectrochemical ethanol sensors and a new generation of energy conversion devices.
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      PubDate: 2017-04-11T02:08:04Z
      DOI: 10.1016/j.apcatb.2017.03.027
      Issue No: Vol. 210 (2017)
  • A catalytic approach to synthesis of PLP analogs and other environmental
           protocols in a single handed CaO/TiO2 green nanoparticle
    • Authors: Sk Jahir Abbas; P.V.R.K. Ramacharyulu; Hsin-Hsi Lo; Sk Imran Ali; Shyue-Chu Ke
      Pages: 276 - 289
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Sk Jahir Abbas, P.V.R.K. Ramacharyulu, Hsin-Hsi Lo, Sk Imran Ali, Shyue-Chu Ke
      As our precursory stage we have focus straight forward on clean catalytic approach for the production of C3 substituted pyridoxal-5′-phosphate analogues of vitamin B6, and other environmental protocols like photocatalytic activity, green fossil fuels and c–c coupling using efficient biocompatible eggshell related unrivalled materials which show versatility of the catalytic effect on different inorganic support. The eggshell immobilized nanoparticles have encouraging relevance in creation of new molecules and can advantageously be studied by various spectroscopic, thermal and elemental analyses like powder X-ray diffraction (XRD), Raman spectroscopy, UV–vis, Scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area analysis. The elucidate nature of nanoparticles offer: more active site acts as lewis acid, vacancies on the catalyst surface and good to better yield of C3 substituted deoxy and 2-nor deoxy coenzyme pyridoxine (PN), coupling products propargylamines (PA), photo degrading enhancement of MB and nucleophilic substituted fatty acid (BD). This enzyme cofactor explore molecular synthons to synthetic equivalent: 3-deoxy and 2-nor-3-deoxy pyridoxal (PL), pyridoxal oxime (PO), pyridoxamine (PM) and mono phosphate derivative of 3-deoxyPM, 3-deoxyPL respectively and chemistry of selective oxidation and schiff base mechanism was studied and complemented through combined experimental and theoretical molecular orbital calculation consequently. The heterogeneous catalyst has strong selective ability towards selective reducing pyridine diester, bioactive intermediates substances and holds vast potential towards separation for the photogenerated electron-hole pairs and renewable, nontoxic, biodegradable green fossil fuels. The catalyst including environmental concern is reapplicable and strong impressive that can unfold the space of worthy metal component widely and facilitate the scope to take a vital role in different fileds like catalysis, biochemistry, nanoscience, energy and materials science.
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      PubDate: 2017-04-11T02:08:04Z
      DOI: 10.1016/j.apcatb.2017.03.075
      Issue No: Vol. 210 (2017)
  • One-step synthesis of CdS nanoparticles/MoS2 nanosheets heterostructure on
           porous molybdenum sheet for enhanced photocatalytic H2 evolution
    • Authors: Lili Zhao; Jin Jia; Zhiyuan Yang; Jiayuan Yu; Aili Wang; Yuanhua Sang; Weijia Zhou; Hong Liu
      Pages: 290 - 296
      Abstract: Publication date: 5 August 2017
      Source:Applied Catalysis B: Environmental, Volume 210
      Author(s): Lili Zhao, Jin Jia, Zhiyuan Yang, Jiayuan Yu, Aili Wang, Yuanhua Sang, Weijia Zhou, Hong Liu
      Co-catalysts for H2 production are often made from expensive noble metals, such as the most efficient Pt. The alternative non-noble metal co-catalysts with low cost and high efficiency are therefore highly desirable for economically viable H2 production. Herein, we demonstrated that a CdS/MoS2/Mo sheets system simultaneously containing photocatalysts, co-catalysts, and conductive supports, was prepared via the one-step hydrothermal process by Mo sheets as template and Mo sources. The obtained CdS/MoS2/Mo sheets possess the superior photocatalytic H2 production via water splitting under visible light irradiation, which achieved an extraordinary H2 production of 4540μmolh−1 g−1, up to 28.6 and 3.6 times greater than that of CdS alone and Pt/CdS. The synergetic effect of MoS2 as co-catalysts and Mo sheets as conductive supports contribute to the dramatically improved photocatalytic H2 evolution activity of CdS photocatalysts, by means of facilitating charge carriers separation and providing active sites for proton reduction. These findings provide a straightforward and practical route to produce cheap and efficient co-catalysts for large-scale water splitting.
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      PubDate: 2017-04-11T02:08:04Z
      DOI: 10.1016/j.apcatb.2017.04.003
      Issue No: Vol. 210 (2017)
  • Lignin-derived Pt supported carbon (submicron)fiber electrocatalysts for
           alcohol electro-oxidation
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): F.J. García-Mateos, T. Cordero-Lanzac, R. Berenguer, E. Morallón, D. Cazorla-Amorós, J. Rodríguez-Mirasol, T. Cordero
      Lignin fibers, with and without phosphorus, and loaded with platinum have been prepared in a single step by electrospinning of lignin/ethanol/phosphoric acid/platinum acetylacetonate precursor solutions. Thermochemical treatments have been carried out to obtain lignin-based carbon fiber electrocatalysts. The electrospun lignin fibers were thermostabilized in air and carbonized at 900°C. The effect of phosphorus and platinum content on the porous texture, the surface chemistry and the oxidation/electro-oxidation resistance have been studied. Phosphorus-containing carbon fibers develop a higher surface area (c.a. 1200m2 g−1), exhibit a lower Pt particle size (2.1nm) and a better particle distribution than their counterpart without phosphorus (c.a. 750m2 g−1 of surface area and 9.6nm Pt particle size). It has been proved that phosphorus improves the oxidation and electro-oxidation resistance of the fibers, avoiding their oxidation during the preparation thermal stages and is responsible of the generation of a microporous material with an unusual wide operational potential window (1.9V). An important Pt–P synergy has been observed in the oxygen transfer during the oxidation and electro-oxidation of the fibers. The obtained carbon fibers can act directly as electrodes without any binder or conductivity promoter. The fibers with platinum have shown outstanding catalyst performance in the electro-oxidation of methanol and ethanol.
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      PubDate: 2017-04-25T10:53:54Z
  • Pure and Fe-doped CeO2 nanoparticles obtained by microwave assisted
           combustion synthesis: Physico-chemical properties ruling their catalytic
           activity towards CO oxidation and soot combustion
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Tapas R. Sahoo, Marco Armandi, Rossella Arletti, Marco Piumetti, Samir Bensaid, Maela Manzoli, Sirish R. Panda, Barbara Bonelli
      A sample of pure CeO2 and two samples of Fe-doped CeO2 containing either 3 or 6 at.% Fe were obtained by microwave assisted combustion synthesis. The powders were extensively characterized by several techniques and tested as catalysts for both CO oxidation and soot combustion. As-synthesized CeO2 nanoparticles have a mostly squared shape and size well below 100nm; they are characterized by the presence of surface Ce3+ species likely due to the occurrence of very defective ceria crystalline phases, as revealed by HR-TEM. Oxidation at 400°C leads to the formation of a hydroxyls-rich surface, with several types of OH groups related to both Ce4+ and Ce3+ species; reduction in H2 at mild temperature (200°C) leads both to reduction of surface Ce4+ to Ce3+ and formation of new OH groups. With respect to CeO2 nanoparticles, Fe-doped ones have, as a whole, a larger size and less abundant surface OH species. A core-shell structure is inferred where Fe is mostly present in the shell, both in a secondary phase (CeFeO3) and as a dopant, finally lowering the band gap of the material. The presence of Fe improved samples reducibility, as shown by the lowering of the onset of temperature programmed reduction. Catalytic tests of CO oxidation showed that surface Fe species significantly improve the catalytic performance of the samples, by lowering the onset of CO conversion to CO2 especially at low Fe content (i.e. 3 at.%), whereas at 6 at.% Fe loading, the preferential formation of the secondary phase CeFeO3 occurs, finally lowering the CO conversion with respect to the sample containing 3 at.% Fe. Conversely, the soot combustion activity was higher for pure CeO2 nanoparticles, likely due to their smaller size, which increases the amount of solid–solid contact points between soot and the catalyst. However, a positive effect of the presence of surface Fe species on the catalytic activity towards soot combustion was observed, as well.
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      PubDate: 2017-04-25T10:53:54Z
  • Composites derived from exfoliated Laponite and Mn-Al hydrotalcite
           prepared in inverse microemulsion: A new strategy for design of robust
           VOCs combustion catalysts
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Bogna D. Napruszewska, Alicja Michalik-Zym, Roman Dula, Elżbieta Bielańska, Wojciech Rojek, Tadeusz Machej, Robert P. Socha, Lidia Lityńska-Dobrzyńska, Krzysztof Bahranowski, Ewa M. Serwicka
      A novel strategy of designing combustion catalysts is proposed, in which catalytically active oxide nanoparticles, obtained by inverse microemulsion method, are trapped between randomly oriented clay layers. MnAl hydrotalcite-like compound was used as the precursor of the active phase, while synthetic smectite Laponite RD, either in sodium form (Na-L) or as an organoclay, exchanged with cetyltrimethylammonium cations (CTA-L), served as the clay component. The composite catalysts were characterized with XRF, XRD, SEM, TEM/HRTEM, TG/DSC, H2 TPR, XPS, and N2 adsorption/desorption at −196°C. It was found that the degree of clay exfoliation was higher in materials obtained from CTA-L than in the catalysts prepared from Na-L. In organo-Laponite based composites the MnOx particles were smaller, more uniform, and better dispersed. Upon calcination they evolved towards well ordered, slightly oxygen-rich Mn3O4 nanocrystals, while in Na-L derived catalysts the MnOx grains were structurally less ordered and size-wise more diversified, of average oxidation state significantly higher than that characteristic of Mn3O4. All synthesized materials were highly active in combustion of toluene. Performance of composites based on Na-L was more susceptible to thermal degradation, while the organoclay-based catalysts improved their performance on the increase of the calcination temperature, showing eventually superior activity. The observed dependencies are discussed in terms of structure-composition-performance relationship. It is argued that, on one hand, the use of organoclay facilitates dispersion of the precursor micelles between the clay layers and prevents the occurrence of active phase coalescence, on the other, provides interlayer fuel for the additional heat input during calcination, enabling formation of well ordered, uniform, Mn3O4 nanocrystals with oxygen-rich surface of unique redox and catalytic properties. The obtained results demonstrate the potential of using organoclays as supports for the active oxide phase prepared from inverse micellar precursors.
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      PubDate: 2017-04-25T10:53:54Z
  • COx-free hydrogen production via decomposition of ammonia over
           Cu–Zn-based heterogeneous catalysts and their activity/stability
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Špela Hajduk, Venkata D.B.C. Dasireddy, Blaž Likozar, Goran Dražić, Zorica Crnjak Orel
      Cu–Zn mixed metal oxides were synthesized with a modified citrate method, supported on an Al2O3 substrate, and tested for ammonia decomposition process to attain a high-purity hydrogen generation for fuel cells. Alumina-supported catalytic materials prepared by wet impregnation technique exhibited the highest surface copper species dispersion along with an increase in distributed acidic and basic sites. TPD studies using NH3 and CO2 revealed the presence of the Lewis and Brønsted acidity and basicity. SEM demonstrated a uniform particle distribution and morphology, regardless of Cu/Zn ratio. Cu/ZnO/Al2O3 exhibited a superior conversion activity when compared to neat Cu–Zn, which may be due to an improved Cu–Zn synergistic effect, a smaller average bimetallic nanoparticle size, and moderate acid–base characteristics. TEM micrographs confirmed the round-shaped metallic particles, ranging up to 7nm in diameter and comprising both active copper oxide phases (Cu1+ and Cu2+), further investigated by EELS spectroscopy, as well as by XPS analysis. With reactions resulting in an effective first-order turnover (rate-determining step limitation), the apparent activation energies of (50–80)±5kJmol−1 were estimated in between 450 and 600°C which is in agreement with other commercial catalysts. All fabricated bi-functional catalysts exhibited a high long-term stability and hydrogen productivity; nonetheless, comprised no critical scarce raw resources (e.g. platinum-group metals), which is appealing for emerging chemically-bonded H2 storage and release be it in relation to production only (electrolysis) or with consumption (regenerative fuel cells).
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      PubDate: 2017-04-25T10:53:54Z
  • Activated carbon-mediated base hydrolysis of alkyl bromides
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Hsin-Se Hsieh, Joseph J. Pignatello
      Activated carbon (AC) is widely used as an adsorbent in water and air purification, but recent studies show that AC can also mediate chemical reactions at ambient temperature, including electron-transfer, redox, free radical, and dehydrohalogenation. Here, we expand the repertoire of such reactions to SN2 base hydrolysis of alkyl bromides. Detailed studies were carried out on the quarantine and pre-shipment fumigant, methyl bromide (MeBr), whose removal from fumigation vent streams is sought due to its ozone-depleting potential. Mixed with a 1M solution of NaOH, ACs are effective adsorbents, but also participate in hydrolysis of MeBr to bromide, methanol, and dimethyl ether. MeBr decay is first order in MeBr and obeys a two-term rate law corresponding to aqueous- and adsorbed-state reactions. The adsorbed-state reaction is, i) unassisted by surface groups, as shown by cycling experiments; ii) 0.83 order in aqueous hydroxide concentration suggesting participation of adsorbed hydroxide; iii) accelerated by pre-adsorption of quaternary ammonium surfactants, which also shift the zeta potential into the positive region; and iv) inhibited by competing inert anions in the order of their chromatographic retention time on ion-exchange resins: Br− <NO3 − <ClO4 −. The results support an anion exchange mechanism in which hydroxide is attracted to positive sites on the carbon. Normalized to aqueous-phase rate constants, adsorbed-state rate constants for RBr followed the order, R=methyl>ethyl>propyl.
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      PubDate: 2017-04-25T10:53:54Z
  • Peroxymonosulfate enhanced visible light photocatalytic degradation
           bisphenol A by single-atom dispersed Ag mesoporous g-C3N4 hybrid
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Yanbin Wang, Xu Zhao, Di Cao, Yan Wang, Yongfa Zhu
      Single-atom dispersed Ag modified mesoporous graphitic carbon nitride (Ag/mpg-C3N4) hybrid was synthesized by co-condensation method and employed as a visible light photocatalyst. In the presence of peroxymonosulfate (PMS), Ag/mpg-C3N4 showed excellent performance for the degradation of bisphenol A (BPA). 100% BPA and 80% TOC could be removed with 0.1g/L catalyst and 1mM PMS under visible light (λ>400nm) within 60min. The reason for the enhanced performance is possibly due to the synergistic effect of single-atom Ag and mpg-C3N4. On the one hand, more visible light could be captured with the introduction of Ag; on the other hand, the existence of PMS promotes the separation efficiency of photogenerated electron-hole pairs. Electron spin resonance (ESR) and free radicals quenching experiment suggest that the major reactive oxygen species (ROS) are sulfate radical (SO4 −), superoxide radicals (O2 −) and photogenerated holes, while the role of hydroxyl radicals (OH) is insignificant in this process. The findings of this work highlighted the great potential of g-C3N4 as photocatalysts and elucidated a new opportunity for PMS remediation of contaminated water.
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      PubDate: 2017-04-25T10:53:54Z
  • Probing the intrinsic active sites of modified graphene oxide for aerobic
           benzylic alcohol oxidation
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Shanhui Zhu, Youliang Cen, Miao Yang, Jing Guo, Chengmeng Chen, Jianguo Wang, Weibin Fan
      The graphene-based materials, particularly graphene oxide (GO) with rich oxygenated groups, exhibit high catalytic performance in various metal-free oxidation reactions. However, the intrinsic active site is still unclear, which greatly retards to further develop advanced catalysts. Here, the modified graphene oxide (abGO) was synthesized by sequential base and acid treatment and employed in the aerobic oxidation of benzyl alcohol to benzaldehyde. This novel catalyst displayed much higher activity, selectivity and stability than that of conventional GO. 93.1% conversion and 100% selectivity were achieved over abGO. More importantly, it is shown that the yield of benzaldehyde is linearly proportional to the content of surface phenol hydroxyl groups. Experimentally observed reactivity trends, structure-behavior correlation, molecule mimicking and characterization results strongly confirm that the surface phenol hydroxyl groups are the intrinsic active sites.
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      PubDate: 2017-04-25T10:53:54Z
  • Structure defects assisted photocatalytic H2 production for polythiophene
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Xupeng Zong, Xiang Miao, Shixin Hua, Li An, Xiang Gao, Wenshuai Jiang, Dan Qu, Zhijun Zhou, Xingyuan Liu, Zaicheng Sun
      Conjugated polymers (CPs) have been demonstrated to be excellent solar energy conversion materials, however, it is considered that pure CPs are not able to photocatalyze water splitting because of the fast recombination of photogenerated charge carriers. Here, we found polythiophene (PTh) nanofibrous structure can have a decent photocatalytic activity (2.19mmolh−1 g−1) and stability in ascorbic acid aqueous solution under visible light irradiation. Furthermore, PTh synthesized at high temperature will introduce structure defects, such as, α–β’ coupling and end groups, which are beneficial to the charge separation. In addition, PTh synthesized at low temperature has long polymer chain and ordered arrangement of chain, which enhanced the light adsorption. Considering both light adsorption and charge separation, PTh compound nanostructure was rationally designed, PTh synthesized at low temperature as core to obtain good light adsorption and PTh prepared at high temperature as sheath to form more structure defects to promote charge separation. This PTh compound nanostructure exhibit higher photocatalytic H2 production performance (2.8mmolh−1 g−1). Our finding may open a door for conjugated polymer for photocatalyst.
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      PubDate: 2017-04-25T10:53:54Z
  • Nanoporous hydrogenated TiO2 photocatalysts generated by underwater
           discharge plasma treatment for solar photocatalytic applications
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Ha-Rim An, So Young Park, Jin Young Huh, Hyeran Kim, Young-Chul Lee, Young Boo Lee, Yong Chul Hong, Hyun Uk Lee
      In this paper, we report on the mass production, characteristics and application of a hydrogenated TiO2 photocatalyst (H-TiO2) with high reactivity under solar light irradiation. The H-TiO2 photocatalyst has been prepared by simple sol-gel method/underwater discharge plasma treatment at room temperature and atmospheric pressure. The optical absorption spectrum of TiO2 can be extended from the ultraviolet (UV) into the visible range by changing the surface properties. The crystallinity, hydrogenation and porosity of TiO2 can be greatly enhanced within 90s through underwater discharge plasma, using amorphous TiO2 (as-synthesized TiO2, a-TiO2) as the precursor. The resultant H-TiO2 showed high bicrystalline (anatase/brookite phases) and a large surface area (267.5m2/g), thus improving photocatalytic activity. We have demonstrated that H-TiO2 showed significant photocatalytic efficiencies for degradation of reactive black 5, rhodamine B, and phenol under solar light irradiation, up to 10 times higher than those of commercial TiO2 and a-TiO2, leading to complete water purification. Interestingly, the H-TiO2 photocatalyst also exhibited strong antimicrobial activities against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus under solar light irradiation, up to 5-times greater than those of commercial TiO2 and a-TiO2. Given that H-TiO2 can be mass produced and easily processed by underwater discharge plasma, we expect this plasma technology may find important environmental and medical applications.
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      PubDate: 2017-04-25T10:53:54Z
  • Separation-free TiO2-graphene hydrogel with 3D network structure for
           efficient photoelectrocatalytic mineralization
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Xianjie Chen, Qian Chen, Wenjun Jiang, Zhen Wei, Yongfa Zhu
      Herein, TiO2-graphene hydrogel (TGH) electrodes with 3D network structure were designed and fabricated successfully via the one-pot method and the photoelectrocatalytic mineralization ability over TGH electrodes was studied in a dynamic system. TGH electrodes showed interconnected open-framework and large specific surface area, which greatly improved the adsorption capacity for organic pollutants. Most interestingly, TGH electrodes exhibited remarkably superior photoelectrocatalytic degradation activity for MB and phenol, the removal rate was 3 times higher than that of P25. In this process, strong oxidizing h+ and OH radicals worked as the main active groups, contributed to the deep mineralization ability for organic pollutants over TGH electrodes. The efficient photoelectrocatalytic mineralization ability of TGH electrodes should mainly benefit from the synergism between adsorption-enrichment and in-situ photoelectrocatalytic oxidation, and the extremely fast transfer for photogenerated electrons on graphene hydrogel. Besides, TGH electrodes not only took advantage of the efficient activity of nano-photocatalysts, but also possessed the separation-free feature. Overall, a facile route to construct 3D network-structure hydrogels with efficient photoelectrocatalytic mineralization ability was revealed and can potentially be utilized in water purification.
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      PubDate: 2017-04-25T10:53:54Z
  • Photocatalytic activity of mont-La (6%)-Cu0.6Cd0.4S catalyst for phenol
           degradation under near UV visible light irradiation
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): H. Boukhatem, H. Khalaf, L. Djouadi, F.V. Gonzalez, R.M. Navarro, J.A. Santaballa, M. Canle
      A mont-La (6%)-Cu0.6Cd0.4S nanocomposite was prepared by a simple cation exchange and impregnation method and its application for the phenol removal from wastewater was studied. The photocatalyst was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (XEDS) and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). Phenol in aqueous solution was used as a model compound for evaluation of near UV–vis (filter cut-off for λ ≥366nm) photocatalytic activity. We have studied the following parameters: load of photocatalyst, load of phenol, pH, [O2], and irradiation wavelength. Within 240min, heterogeneous suspensions of 1g·L−1 of mont-La (6%)-Cu0.6Cd0.4S nanocomposite allowed removal of ca. 86% of 20mg·L−1 solution of phenol at pH=5.44, with dissolved oxygen from air, with 77.8% TOC removal. The kinetics of photocatalytic transformation followed the Langmuir–Hinshelwood kinetic model. Pseudo-first-order kinetics adequately fitted the experimental data and the obtained rate constants are reported. With the mont-La (6%)-Cu0.6Cd0.4S catalyst 84% removal of phenol degradation efficiency was achieved after five consecutive photocatalytic cycles. Twelve main photoproducts were observed from phenol photodegradation, using HPLC–MS. The used photocatalyst is promising for green chemistry use in abatement of persistent organic pollutants.
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      PubDate: 2017-04-25T10:53:54Z
  • Zinc and platinum co-doped ceria for WGS and CO oxidation
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Ravikiran Mandapaka, Giridhar Madras
      This study presents the synthesis and application of zinc and platinum co-doped ceria for CO oxidation and water gas shift reaction (WGS). To synthesize the catalyst, novel combustion synthesis procedure at pH=10 has been employed, yielding the catalyst in single step without further purification procedures. The catalyst was found to be active under high temperature conditions (>350°C) thus asserting the functionality of the catalyst as single stage WGS catalyst. In this study, we have also developed a dual site redox mechanism to understand the intrinsic kinetics of WGS reaction. For the proposed mechanism, a plausible microkinetic model has been developed for WGS and CO oxidation reactions, respectively. In line with the application of reaction route (RR) analysis to the microkinetic models developed for single site pathway for WGS. In this study, we have extended the RR approach to dual site redox mechanism. From the above analysis, the surface dissociation of OH surface species was found to be rate determining step of the mechanism. The rate expression developed using RR analysis was validated through isothermal plug flow reactor (PFR) model. The PFR simulations predicted the experimental trend for wider range of temperature conditions thus portraying the significance of the microkinetic model developed in this study.
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      PubDate: 2017-04-25T10:53:54Z
  • Three dimensional few-layer porous carbon nanosheets towards oxygen
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Jian Zhang, Chenyu Zhang, Yufeng Zhao, Ibrahim Saana Amiinu, Huang Zhou, Xiaobo Liu, Yongfu Tang, Shichun Mu
      Novel three dimensional (3D) porous carbon nanosheets with few layers are successfully prepared using intrinsically porous cellulose as carbon matrix only by means of calcination and KOH activation. Further, the N-doped 3D carbon nanosheets show high density of pyridinic N and extremely high specific surface area (1756m2 g−1). As oxygen reduction catalyst, they possess an outperformed onset (E0 =−0.03V) and half-wave (E1/2 =−0.17V) potential compared with the platinum (Pt) electrocatalyst (E0 =−0.05V, E1/2 =−0.2V) in an alkaline system. In addition, excellent electrochemical stability as well as improved CO poisoning resistance and suppressed methanol crossover relative to Pt is also obtained. In an acid system, the catalyst also exhibits good activity and higher durability than Pt/C. Significantly, when used as a catalyst of the air electrode for Zn–air batteries, it demonstrates a higher peak power density of 208mWcm−2 and a voltage plateau at the controlled discharge current density compared to the commercial Pt/C electrode. This simple and scalable approach provides a direct route to synthesize low cost and highly efficient electrocatalysts from biomass without addition of extra metal catalysts.
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      PubDate: 2017-04-25T10:53:54Z
  • An advanced TiO2/Fe2TiO5/Fe2O3 triple-heterojunction with enhanced and
           stable visible-light-driven fenton reaction for the removal of organic
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Yuanxin Deng, Mingyang Xing, Jinlong Zhang
      The construction of catalysts with high efficiency and stability for heterogeneous Photo-Fenton reaction Heterogeneous (PFR) has been a major challenge for the degradation of organic pollutants. Here, we successfully develop an advanced TiO2/Fe2TiO5/Fe2O3 triple-heterojunction structure by using the mesoporous TiO2 spheres as the substrate via a simple ion-exchange method. The XRD and HRTEM results demonstrate the generation of Fe2TiO5 on the interface between TiO2 and Fe2O3, which can be used as a “bridge” to transfer the photo-excited electrons from TiO2 to Fe2O3. The as-prepared triple-heterojunction has abundant interphase boundaries which greatly improve the migration of photo-excited charges among different components. As a result, the prepared triple-heterojunction has a significantly enhanced PFR activity for the visible-light-driven degradation of methyl orange (MO) and colorless organic pollutant of phenol, compared with the single catalysts of Fe2O3 and TiO2, and the binary-heterojunction of TiO2/Fe2O3. Compared to the traditional Fe2O3 based PFR, the degradation rates of MO and phenol over triple-heterojunction can be increased from 4% to 87% within 10min irradiation and from 38% to 100% within 60min irradiation, respectively. And the total organic carbon (TOC) degradation rate of phenol can be up to 85%. Moreover, this advanced triple-heterojunction has a wide pH value range of application in PFR. Either at a pH of 4.0 or 7.0, it shows a much higher and more stable PFR activity for the degradation of MO than the catalysts of Fe2O3 and TiO2/Fe2O3. And the reaction rate of TiO2/Fe2TiO5/Fe2O3 almost keeps changeless even after 10th cycles, suggesting its vast application foreground in the environmental pollutant treatment.
      Graphical abstract image

      PubDate: 2017-04-25T10:53:54Z
  • Mesoporous Ru/MgO prepared by a deposition-precipitation method as highly
           active catalyst for producing COx-free hydrogen from ammonia decomposition
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Xiaohua Ju, Lin Liu, Pei Yu, Jianping Guo, Xilun Zhang, Teng He, Guotao Wu, Ping Chen
      Development of highly active catalyst for producing COx-free H2 from ammonia decomposition is critical for the utilization of ammonia as H2 carrier in proton exchange membrane fuel cell. Here, we present a deposition–precipitation (DP) method towards the synthesis of a highly active and stable mesoporous Ru/MgO catalyst for NH3 decomposition reaction. Nitrogen sorption measurements show that the deposition–precipitation method can introduce mesoporosity into the Ru/MgO-DP catalysts. Much enhanced Ru dispersion can be observed for the mesoporous Ru/MgO-DP catalysts in comparison with that of the Ru/MgO catalysts prepared by impregnation method due to the high surface area and plenty of mesopores of the Ru/MgO-DP catalysts. As a result, the mesoporous Ru/MgO-DP catalysts show significantly improved catalytic activity for NH3 decomposition. The activity of Ru/MgO-DP catalyst can be further remarkable enhanced with KOH, which can give comparable catalytic performance with that of the most efficient carbon nanotube supported Ru catalyst.
      Graphical abstract image

      PubDate: 2017-04-25T10:53:54Z
  • Co3O4-Al2O3 mesoporous hollow spheres as efficient catalyst for
           Fischer-Tropsch synthesis
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Xin-Pu Fu, Qi-Kai Shen, Dong Shi, Ke Wu, Zhao Jin, Xu Wang, Rui Si, Qi-Sheng Song, Chun-Jiang Jia, Chun-Hua Yan
      Nanostructured mixed metal oxides with porous hollow-interior structure hold great promise in environmental-related catalysis, owing to their excellent catalytic properties. However, facile fabrication of such mesoporous architecture is still challenging. Here, by using a transient aerosol-assisted self-assembly (AASA) method, we synthesized the Co3O4-Al2O3 mesoporous hollow spheres (MHS) composed of thermally stable Co3O4 nanoparticles partially anchored to amorphous interfacial Al2O3. The as-prepared Co3O4-Al2O3 nanocomposites displayed distinct features of large pore volume and stable assembled morphology, and thus showed significant advantages in mass transfer and redox behavior. For Fischer-Tropsch synthesis, a very important reaction in fuel production, the Co3O4-Al2O3 MHS exhibited significant catalytic performance in conversion, selectivity and stability for the desired gasoline products. Therefore, we provide a facile and controlled approach towards the preparation of mesoporous hollow materials to achieve novel mixed metal oxide nanocatalysts those are good candidates in energy-production application.
      Graphical abstract image

      PubDate: 2017-04-25T10:53:54Z
  • Hydrogenation of aqueous nitrate and nitrite with ruthenium catalysts
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Xiangchen Huo, Daniel J. Van Hoomissen, Jinyong Liu, Shubham Vyas, Timothy J. Strathmann
      Historically, development of catalysts for treatment of nitrate-contaminated water has focused on supported Pd-based catalysts, but high costs of the Pd present a barrier to commercialization. As part of an effort to develop lower cost hydrogenation catalysts for water treatment applications, we investigated catalysts incorporating Ru with lower cost. Pseudo-first-order rate constants and turnover frequencies were determined for carbon- and alumina-supported Ru and demonstrated Ru’s high activity for hydrogenation of nitrate at ambient temperature and H2 pressure. Ex situ gas pretreatment of the catalysts was found to enhance nitrate reduction activity by removing catalyst surface contaminants and exposing highly reducible surface Ru oxides. Ru reduces nitrate selectively to ammonium, and no aqueous nitrite intermediate is observed during reactions. In contrast, reactions initiated with nitrite yield a mixture of two endproducts, with selectivity shifting from ammonium towards N2 at increasing initial aqueous nitrite concentrations. Experimental observation and Density Functional Theory calculations together support a reaction mechanism wherein sequential hydrogenation of nitrate to nitrite and NO is followed by parallel pathways involving the adsorbed NO: (1) sequential hydrogenation to ammonium, and (2) N–N coupling with aqueous nitrite followed by hydrogenation to the detected N2O intermediate and N2 endproduct. These findings open the door to development of alternative catalysts for purifying and recovering nutrients from nitrate-contaminated water sources, and insights into the controlling surface reaction mechanisms can guide rational design efforts aimed at increasing activity and tuning endproduct selectivity.
      Graphical abstract image

      PubDate: 2017-04-25T10:53:54Z
  • Photocatalytic performance enhancement of CuO/Cu2O heterostructures for
           photodegradation of organic dyes: Effects of CuO morphology
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Denghui Jiang, Jianbin Xue, Liqiong Wu, Wei Zhou, Yuegang Zhang, Xinheng Li
      Cuprous oxide is a promising candidate for photocatalysis. But its photocatalytic properties still need to be much improved for applications. Herein, we report a kind of heterostructures (HCs), i.e. CuO/Cu2O HCs. Different morphologies of CuO, i.e. nanowires, nanotetrahedra and nanospheres, have been controllably prepared on Cu2O cubes/octahedra by a facile wet chemical method. All the obtained CuO/Cu2O HCs have significantly improved photocatalytic activity and stability as compared to Cu2O. Especially, the nanowires CuO/Cu2O have shown a specific reaction rate ca. 1.6μmolmin−1 g−1, 260 times as high as pristine Cu2O and 4 times as Au/Cu2O. And the nanospheres CuO/Cu2O have maintained over 95% of photocatalytic activity after 7 cycles. So, distinct morphologies of CuO have resulted in dramatic effects on photocatalytic properties of CuO/Cu2O HCs.
      Graphical abstract image

      PubDate: 2017-04-25T10:53:54Z
  • Synthesis of hierarchical platinum-palladium-copper nanodendrites for
           efficient methanol oxidation
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Rong Chang, Lijun Zheng, Chengwen Wang, Dachi Yang, Gaixia Zhang, Shuhui Sun
      Tuning the architecture and composition of platinum (Pt)-based nanostructures for enhancing the electrocatalytic activity and stability towards methanol oxidation reaction (MOR) is pivotal for the commercialization of direct methanol fuel cells (DMFCs), but still remains great challenge. Here, hierarchical platinum-palladium-copper (PtPdCu) nanodendrites (NDs) with tip-cracked defects have been developed with tailored morphology and dopants. We firstly electrodeposited PtPdCu nanowires (NWs) inside the channels of aluminum anodic oxide (AAO) template, and then wet-chemically transformed the as-synthesized NWs into NDs. Benefiting from the synergetic effect between the tip-cracked defects and dopants, firstly, the MOR mass activity and specific activity of PtPdCu NDs are ∼1.78 times and ∼2.14 times higher than those of commercial Pt/C, respectively; secondly, after 2000s stability test, the electrocatalytic activity of PtPdCu NDs is ∼5.02 times higher than commercial Pt/C; finally, the PtPdCu NDs also show better CO tolerance as well. Our PtPdCu NDs are promising anode electrocatalysts in next-generation DMFCs.
      Graphical abstract image

      PubDate: 2017-04-25T10:53:54Z
  • Cerium modified birnessite-type MnO2 for gaseous formaldehyde oxidation at
           low temperature
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Lin Zhu, Jinlong Wang, Shaopeng Rong, Haiyan Wang, Pengyi Zhang
      Cerium modified birnessite-type manganese dioxides (Ce-MnO2) with different doping ratios were prepared by a redox reaction of KMnO4 with (NH4)2C2O4 in the presence of Ce(NO3)3. The as-synthesized Ce-MnO2 samples were characterized by XRD, SEM, TEM, BET, XPS, ICP-AES, H2-TPR, Raman and in situ DRIFTS. The results indicate that doping of cerium significantly enhance the performance of birnessite for HCHO removal at low temperature. Ce-MnO2(1:10) with the nominal Ce/Mn ratio of 1:10 exhibited the best activity and achieved complete HCHO conversion at 100°C and better activity at room temperature than undoped birnessite. Upon the doping of cerium, the growth of MnO2 crystal was inhibited, leading to smaller particle size and higher specific surface. In addition, CeO2 nanocrystal formed even at low doping ratio (0.1:10), resulting in close contact between CeO2 and MnO2 nanocrystals. As a result, the doped material owned higher content of oxygen vacancies and surface adsorbed oxygen species, which contributed to its high activity for HCHO oxidation. This investigation provides a new point of view about how to design an inexpensive efficient catalyst for indoor air purification via introducing appropriate content of cerium.
      Graphical abstract image

      PubDate: 2017-04-25T10:53:54Z
  • Six-flux absorption-scattering models for photocatalysis under
           wide-spectrum irradiation sources in annular and flat reactors using
           catalysts with different optical properties
    • Abstract: Publication date: 15 August 2017
      Source:Applied Catalysis B: Environmental, Volume 211
      Author(s): Ivana Grčić, Gianluca Li Puma
      The photocatalytic oxidation of 2-hydroxybenzoic acid (2-HBA) in an annular tubular reactor (R1) and a flat rectangular open channel reactor (R2), which were irradiated with light sources emitting in the UVB, UVA and visible range of the solar radiation spectrum, and using two photocatalysts, titanium dioxide (TiO2 P25) and Ag-modified TiO2 P25 (Ag@TiO2) was modeled. The local volumetric rate of photon absorption (LVRPA) in the reactors was evaluated by the six-flux absorption scattering model (SFM). The Langmuir-Hinshelwood kinetic model of the degradation of a model contaminant on irradiated aqueous suspensions of TiO2 P25 and Ag@TiO2 was combined with the SFM radiation model and light emission models to determine local reaction rates, and further integrated with the reactors hydrodynamics and material balances to model the degradation of 2-HBA in the photoreactors. The linear source spherical emission (LSSE) and extensive source superficial diffuse emission (ESSDE) models were compared in terms of incident and transmitted photon fluxes through the reactor. It was shown that both LSSE and ESSDE models could be successfully applied for the modeling of annular and flat reactors, considering the emission from tubular fluorescent light sources. Since current research calls for materials with wide absorption in the solar radiation spectrum, spanning from the UV to the visible, therefore, the SFM model was adapted to consider such wide distribution. The optical properties of the photocatalysts were averaged over narrow wavelength ranges of the solar spectrum, wherein the contributions by the UVA, UVB and visible light irradiation to the LVRPA and contaminant degradation rate were separated. The effects of catalyst concentration, liquid velocity profile and the photon flux from different light sources on the 2-HBA degradation rate were explored. The “intrinsic” reaction kinetic constants of 2-HBA photocatalytic oxidation independent of reactor type, catalyst concentration, irradiance levels and hydrodynamic conditions were determined by fitting the experimental data to the model results. It was shown that the model parameters were independent of the type of catalyst used, although the catalyst exhibited significantly different optical properties.
      Graphical abstract image

      PubDate: 2017-04-25T10:53:54Z
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