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  Subjects -> ENGINEERING (Total: 2279 journals)
    - CHEMICAL ENGINEERING (191 journals)
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    - ELECTRICAL ENGINEERING (101 journals)
    - ENGINEERING (1203 journals)
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ENGINEERING (1203 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 7)
3D Research     Hybrid Journal   (Followers: 19)
AAPG Bulletin     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: 222)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 2)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Active and Passive Electronic Components     Open Access   (Followers: 7)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 6)
Advanced Science     Open Access   (Followers: 4)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 5)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 7)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17)
Advances in Artificial Neural Systems     Open Access   (Followers: 4)
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: 10)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 20)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 24)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
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: 12)
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: 37)
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: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 8)
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 Network Science     Open Access  
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 3)
Applied Sciences     Open Access   (Followers: 2)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 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: 7)
Arid Zone Journal of Engineering, Technology and Environment     Open Access  
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 1)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 8)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Current Engineering & Maths     Open Access  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
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: 4)
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: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 32)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 8)
Biomedical Science and Engineering     Open Access   (Followers: 3)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 2)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription  
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     Hybrid Journal   (Followers: 14)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 41)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 7)
Case Studies in Thermal Engineering     Open Access   (Followers: 3)
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: 3)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 4)
Coatings     Open Access   (Followers: 3)
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: 25)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 255)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 179)
Composites Part B : Engineering     Hybrid Journal   (Followers: 227)
Composites Science and Technology     Hybrid Journal   (Followers: 169)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 13)
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: 28)
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: 10)
Computing and Visualization in Science     Hybrid Journal   (Followers: 5)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 29)
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: 8)
Control Engineering Practice     Hybrid Journal   (Followers: 41)
Control Theory and Informatics     Open Access   (Followers: 7)
Corrosion Science     Hybrid Journal   (Followers: 25)
CT&F Ciencia, Tecnologia y Futuro     Open Access  

        1 2 3 4 5 6 7 | Last

Journal Cover Applied Catalysis B: Environmental
  [SJR: 2.322]   [H-I: 158]   [8 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0926-3373
   Published by Elsevier Homepage  [3034 journals]
  • Structure/redox/activity relationships in CeO2/CuMn2O4 CO-PROX catalysts
    • Authors: A. Elmhamdi; L. Pascual; K. Nahdi; A. Martínez-Arias
      Pages: 1 - 11
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): A. Elmhamdi, L. Pascual, K. Nahdi, A. Martínez-Arias
      CuMn2O4 prepared by a microemulsion method is employed as support of ceria with different loading level (between 5 and 80wt.%) and the CO-PROX properties of corresponding catalysts are explored. The catalysts have been characterized by XRD, SBET measurement, HREM and XEDS, XPS and TPR, which allows establishing a complete model of the structural and chemical characteristics of the catalysts. The characterization results have been correlated with the analysis of CO-PROX catalytic properties performed by means of activity measurements complemented by operando-DRIFTS. Important differences in structural, redox and catalytic properties are detected as a function of the amount of ceria present in the catalyst. These are shown to depend basically on the size of the supported ceria nanocrystals as well as the fact that the increase in the ceria loading gradually increases the interfacial character of surface exposed sites of the support with important implications for the CO-PROX properties of the catalyst.
      Graphical abstract image

      PubDate: 2017-06-02T07:21:05Z
      DOI: 10.1016/j.apcatb.2017.05.070
      Issue No: Vol. 217 (2017)
       
  • Porous TiB2-TiC/TiO2 heterostructures: Synthesis and enhanced
           photocatalytic properties from nanosheets to sweetened rolls
    • Authors: Xueqi Guo; Guosong Zhang; Hongzhi Cui; Na Wei; Xiaojie Song; Jian Li; Jian Tian
      Pages: 12 - 20
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Xueqi Guo, Guosong Zhang, Hongzhi Cui, Na Wei, Xiaojie Song, Jian Li, Jian Tian
      Exposing high surface areas with porous materials and assembling heterostructures with chemical element doping represent a useful approach to producing high-performance photocatalysts. Porous TiB2-TiC/TiO2 heterostructure, a new three-dimensional (3D) porous material with carbon and boron elements, was prepared in this study via alkali-assisted hydrothermal method followed by the in situ growth of porous TiB2-TiC material. The samples as-formed contain a wide variety of morphologies from nanosheet to sweetened roll, and exhibit dramatically enhanced photocatalytic activity for the degradation of methyl orange and rhodamine B compared to pure porous TiB2-TiC materials. The mechanisms for heterostructure formation and photocatalytic effect are analyzed to find that the heterostructures enhanced the separation of the photoinduced carriers, and that the morphological features of TiB2-TiC/TiO2 heterostructures exert a significant influence on the photocatalytic degradation of organic pollutants.
      Graphical abstract image

      PubDate: 2017-06-02T07:21:05Z
      DOI: 10.1016/j.apcatb.2017.05.079
      Issue No: Vol. 217 (2017)
       
  • Synthesis of WO3/BiVO4 photoanode using a reaction of bismuth nitrate with
           peroxovanadate on WO3 film for efficient photoelectrocatalytic water
           splitting and organic pollutant degradation
    • Authors: Qingyi Zeng; Jinhua Li; Linsen Li; Jing Bai; Ligang Xia; Baoxue Zhou
      Pages: 21 - 29
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Qingyi Zeng, Jinhua Li, Linsen Li, Jing Bai, Ligang Xia, Baoxue Zhou
      In this work, we developed a novel, facile, cost-effective method based on a reaction of bismuth nitrate with peroxovanadate on WO3 nanoplate films to synthesize nanostructured WO3/BiVO4 photoanodes, which prevented the introduction of structural defects in the WO3 substrates that occurs in conventional deposition-annealing (DA) methods, for highly efficient photoelectrocatalytic (PEC) water splitting and degradation of organic pollutants. The method is also versatile, allowing dopants such as Mo to be easily incorporated into BiVO4 structures to improve the charge-transfer properties. Both the amount of BiVO4 and doping level can be tailored by modifying the preparation conditions. The PEC performance of the optimized WO3/BiVO4 photoanode was markedly improved with a photocurrent density of 2.83mAcm−2, which was 9.43 times that of a BiVO4 photoanode and 2.19 times that of a WO3 photoanode. A Mo-doped WO3/BiVO4 (WO3/Mo-BiVO4) photoanode exhibited a further enhanced photocurrent density of 3.78mAcm−2. Specifically, a cobalt–phosphate (Co–Pi) co-catalyst decorated WO3/Mo-BiVO4 photoanode showed the highest photocurrent density of 5.38mAcm−2, which is comparable to the values of reported WO3/BiVO4 photoanodes, with stoichiometric H2 (94.7μmolcm−2 h−1) and O2 (46.5μmolcm−2 h−1) evolution. Furthermore, the WO3/Mo-BiVO4 photoanode exhibited efficient performance for PEC degradation of organic pollutants with rate constants of 0.683, 0.385, and 1.05h−1 for tetracycline hydrochloride, phenol, and Congo red, respectively. Intensity-modulated photocurrent spectroscopy measurements indicated the WO3/BiVO4 photoanode should contain fewer nanostructural defects than the WO3/BiVO4 photoanode prepared using DA methods, possibly because the moderate preparation process avoids the harmful repeated heating-cooling process used in DA.
      Graphical abstract image

      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.072
      Issue No: Vol. 217 (2017)
       
  • Self-optimizing bifunctional CdS/Cu2S with coexistence of light-reduced
           Cu0 for highly efficient photocatalytic H2 generation under visible-light
           irradiation
    • Authors: Jiajun Zhang; Weisong Li; Ye Li; Lei Zhong; Chunjian Xu
      Pages: 30 - 36
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Jiajun Zhang, Weisong Li, Ye Li, Lei Zhong, Chunjian Xu
      A self-optimizing bifunctional core-shell CdS/Cu2S heterojunction with high activity and superb stability for the photocatalytic hydrogen evolution under visible light irradiation was synthesized by a simple two-step solvothermal method. Compared with pure CdS, the photocatalytic activity of the hybrid is significantly enhanced by almost 25 times. The sample CdS/Cu2S-30 has shown a maximum H2 evolution rate of 14.4mmolh−1 g−1 with an apparent quantum yield of 19.5% at 420nm. The surface of single-crystalline CdS nanorod is fully covered by Cu2S, observed via SEM and TEM, which benefits the activity of catalyst by shorting radial transfer path of charge carriers and increasing the surface area for reaction. This photocatalyst features both bifunction and self-optimizing. During photo reaction, part of Cu2S is reduced to Cu0 by irradiation on the surface between CdS core and Cu2S shell, while the rest of Cu2S offers plenty of active sites for hydrogen evolution reaction (HER). These generated Cu0 retard the charge carrier recombination process by forming multi-heterojunction. Meanwhile, the self-optimizing of this photocatalyst is realized by Cu/Cu2S ratio on the surface of catalyst varying automatically to the optimal value to adapt to the corresponding reaction condition. Based on all these benefits, hydrogen evolution reaction is facilitated.
      Graphical abstract image

      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.074
      Issue No: Vol. 217 (2017)
       
  • Efficient photodegradation of dye pollutants using a novel plasmonic AgCl
           microrods array and photo-optimized surface-enhanced Raman scattering
    • Authors: Yi-Feng Cheng; Qi Cao; Jie Zhang; Tong Wu; Renchao Che
      Pages: 37 - 47
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Yi-Feng Cheng, Qi Cao, Jie Zhang, Tong Wu, Renchao Che
      A novel arrayed AgCl micro-rods have in situ grown on an Ag foil successfully for the first time. The preparation process is consisted of two facile steps: (1) immersed oxidation and (2) directional ions exchange. The structure of the as-synthesized arrayed substrate has been characterized comprehensively, and the relevant growth mechanism is proposed. This highly aligned AgCl arrays show a remarkable visible-light-driven photocatalytic activity towards degrading 10−5 mol/L rhodamine 6G (R6G) aqueous solution. The ultra-stable catalytic performance of the plasmonic arrays was revealed by the recycled tests in the neutral and acidic conditions. Moreover, a facile SERS substrate based on the AgCl arrays was obtained with the optimal enhancement factor (EF) of ∼3.25×107, by directly putting the substrate under a Xe lamp in 7.5min. Amazingly, the photo-optimized surface-enhanced Raman scattering (SERS) substrate still shows a stable activity for photodegrading R6G. The photocatalytic and SERS mechanism are proposed in this study.
      Graphical abstract image

      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.021
      Issue No: Vol. 217 (2017)
       
  • Defect engineered Ta2O5 nanorod: One-pot synthesis, visible-light driven
           hydrogen generation and mechanism
    • Authors: Xin Yu; Wei Li; Zhonghua Li; Jiawen Liu; Pingan Hu
      Pages: 48 - 56
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Xin Yu, Wei Li, Zhonghua Li, Jiawen Liu, Pingan Hu
      Visible-light photocatalysis of the typical wide band gap semiconductor was often thought to be challenge and focus in the field of solar energy conversion. Hence, it was of great significance for wide band conductors to harvest visible light using photocatalysis technology. In this experiment, we successfully synthesized novel Ta4+ doped Ta2O5 nanorod by facile one-pot vapor hydrolysis method, and Ta4+ species was confirmed by XPS and EPR technology. The as-prepared Ta2O5 nanorod displayed amazing visible light absorption from 400 to 800nm and visible light photocatalytic activity for hydrogen production, and the estimated band gap of Ta2O5-180, Ta2O5-200, Ta2O5-220 and Ta2O5-240 catalysts were about 2.93, 2.83, 2.75 and 2.53eV, much lower than that of commercial Ta2O5 (3.88eV). And the specific surface area of the self-doped Ta2O5 catalyst could reach up to 237.89m2 g−1 with the typical mesoporous structure. It was noteworthy that the self-doped Ta2O5 nanorod displayed inspiring visible light photocatalytic activity for hydrogen production, which could reach up to 23.35μmolg−1 h−1, while commercial Ta2O5 showed no visible light activity, mainly due to the formation of Ta4+ species in the as-prepared Ta2O5 nanorod. Besides, the self-doped Ta2O5 catalyst showed UV light photocatalytic activity of 10.17×103 μmolg−1 h−1 and the highly enhanced simulated sunlight photocatalytic activity of 356.68μmolg−1 h−1 for hydrogen production, which were much higher than those of commercial Ta2O5. It was the formation of the Ta4+ species, high specific surface area, high crystallization and mesoporous structure that highly enhanced the UV light and simulated sunlight photocatalytic activity of the self-doped Ta2O5 nanorod. Finally, possible mechanism of the visible-light photocatalysis of the self-doped Ta2O5 nanorod for hydrogen production was also proposed in detail.
      Graphical abstract image

      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.024
      Issue No: Vol. 217 (2017)
       
  • Compact and uniform TiO2@g-C3N4 core-shell quantum heterojunction for
           photocatalytic degradation of tetracycline antibiotics
    • Authors: Wei Wang; Jiaojiao Fang; Shaofeng Shao; Min Lai; Chunhua Lu
      Pages: 57 - 64
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Wei Wang, Jiaojiao Fang, Shaofeng Shao, Min Lai, Chunhua Lu
      Optimizing the heterojunction structure of semiconductor photocatalysts is significant for taking full advantage of their abilities for organic molecules degradation. Here, we demonstrate a feasible strategy of polymerizing the quantum-thick graphitic carbon nitride (g-C3N4) on to the surface of anatase titanium dioxide (TiO2) nanosheets with exposed {001} facets to form the TiO2@g-C3N4 (TCN) core-shell quantum heterojunction for improving photocatalytic tetracycline degradation activity. 100mg of TCN photocatalyst shows the highest tetracycline degradation rate of 2.2mg/min, which is 36% higher than that of the TiO2/g-C3N4 random mixture (TCN(mix)), 2 times higher than that of TiO2, and 2.3 times higher than that of bulk g-C3N4. Results also indicate that h+ and ·O2 − are the main oxidant species for the efficient photocatalytic reaction. The decisive factors in improving the photocatalytic activity of TCN is the unique structural advantages of quantum-thick g-C3N4 shell, compact and uniform contact interface, richly available reaction sites, more surface adsorbed hydroxyl (OH) groups. Efficient electron transfer between TiO2 and g-C3N4 is also demonstrated by the significant enhancement of photocurrent response of TCN electrodes and decrement of fluorescence emission spectra. This work demonstrates new sights for synthesizing high-efficient and environment-stable photocatalysts by engineering the surface heterojunction.
      Graphical abstract image

      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.037
      Issue No: Vol. 217 (2017)
       
  • Highly efficient removal of bisphenol A by a three-dimensional graphene
           hydrogel-AgBr@rGO exhibiting adsorption/photocatalysis synergy
    • Authors: Fangyuan Chen; Weijia An; Li Liu; Yinghua Liang; Wenquan Cui
      Pages: 65 - 80
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Fangyuan Chen, Weijia An, Li Liu, Yinghua Liang, Wenquan Cui
      The increasing extent of environmental pollution by industrial chemicals necessitates the development of facile methods of their removal. Among the various techniques employed for this purpose, photocatalytic degradation is particularly attractive, since it does not require the use of other chemicals, achieving pollutant mineralization by the action of light and atmospheric oxygen only. However, most photocatalysts suffer from poor stability and recyclability, which limits their practical applications. This study describes the encapsulation of AgBr by reduced graphene oxide to form a composite (AgBr@rGO) that can be incorporated into graphene to form hydrogels (rGH-AgBr@rGO) with three-dimensional (3D) network structures. The core-shell structure of AgBr@rGO inhibited the growth of AgBr particles, achieving excellent control over their size (500-600nm), while hybridization with graphene promoted the rapid migration and separation of photogenerated charges. Bisphenol A (BPA) were rapidly adsorbed by the 3D graphene nanosheets of rGH-AgBr@rGO and promptly degraded by AgBr@rGO nanoparticles under visible-light irradiation, showing that the synergy between adsorption and photocatalytic degradation could significantly improve pollutant removal efficiency. Moreover, the micron-sized 3D mesh structure could be regenerated using a simple filter without the need for a complex catalyst filtration system. The obtained results revealed a superior synergy between photocatalytic and adsorption-based pollutant degradation by rGH-AgBr@rGO, which achieved a 1.5-fold higher BPA removal degree than pure AgBr, exhibiting values above 90% after five consecutive cycles. Finally, the degree of BPA degradation was maintained at 100% during the first 6h under continuous flow conditions.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.078
      Issue No: Vol. 217 (2017)
       
  • Magnetically-actuated mesoporous nanowires for enhanced heterogeneous
           catalysis
    • Authors: Albert Serrà; Sergi Grau; Carolina Gimbert-Suriñach; Jordi Sort; Josep Nogués; Elisa Vallés
      Pages: 81 - 91
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Albert Serrà, Sergi Grau, Carolina Gimbert-Suriñach, Jordi Sort, Josep Nogués, Elisa Vallés
      We study the optimization of the catalytic properties of entirely magnetic Co–Pt compact and mesoporous nanowires of different diameters (25–200nm) by using magnetic actuation. The nanowires are a single-entity, robust, magnetic-catalyst with a huge catalytically-active surface area. We show that apart from conventional parameters, like the size and morphology of the nanowires, other factors can be optimized to enhance their catalytic activity. In particular, given the magnetic character of the nanowires, rotating magnetic fields are a very powerful approach to boost the performance of the catalyst. In particular, the magnetic field induces them to act as nano-stirrers, improving the local flow of material towards the active sites of the catalyst. We demonstrate the versatility of the procedure by optimizing (i) the degradation of different types of pollutants (4-nitrophenol and methylene blue) and (ii) hydrogen production. For example, by using as little as 0.1mgmL−1 of 25nm wide Co–Pt mesoporous nanowires (with ∼3nm pore size) as catalysts, kinetic normalized constants knor as high as 20,667 and 21,750s−1 g−1 for 4-nitrophenol and methylene blue reduction, respectively, are obtained. In addition, activity values for hydrogen production from borohydride are as high as 25.0L H2 g−1 min−1, even at room temperature. These values outperform any current state-of-the-art proposed catalysis strategies for water remediation reactions by at least 10-times and are superior to most advanced approaches to generate hydrogen from borohydride. The recyclability of the nanowires together with the simplicity of the synthetic method makes this approach (using not only Co–Pt, but also other mesoporous magnetic catalysts) very appealing for very diverse types of catalytic applications.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.071
      Issue No: Vol. 217 (2017)
       
  • Heteropoly acid catalysts in upgrading of biorenewables: Cycloaddition of
           aldehydes to monoterpenes in green solvents
    • Authors: Rafaela F. Cotta; Kelly A. da Silva Rocha; Elena F. Kozhevnikova; Ivan V. Kozhevnikov; Elena V. Gusevskaya
      Pages: 92 - 99
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Rafaela F. Cotta, Kelly A. da Silva Rocha, Elena F. Kozhevnikova, Ivan V. Kozhevnikov, Elena V. Gusevskaya
      Acidic Cs salt of tungstophosphoric heteropoly acid, Cs2.5H0.5PW12O40 (CsPW), is excellent solid acid catalyst for liquid-phase cycloaddition reactions of biomass-based and easily available from essential oils monoterpenic compounds, such as limonene, α-terpineol, α-pinene, β-pinene and nerol, with aldehydes, including benzaldehyde, crotonaldehyde as well as biomass-derived cuminaldehyde and trans-cinnamaldehyde. The reactions give oxabicyclo[3.3.1]nonene compounds potentially useful for the fragrance and pharmaceutical industries in good to excellent yields. The process is environmentally benign and can be performed in biomass-derived solvent 2-methyltetrahydrofuran and eco-friendly “green” organic solvents such as dimethylcarbonate and diethylcarbonate under mild conditions at low catalyst loadings without leaching problems. The solid CsPW catalyst can be easily separated from the reaction media and low-boiling solvents can be removed by distillation. Silica-supported H3PW12O40 also demonstrated good performance in these reactions.
      Graphical abstract image

      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.055
      Issue No: Vol. 217 (2017)
       
  • CdS/Pt photocatalytic activity boosted by high-energetic photons based on
           efficient triplet–triplet annihilation upconversion
    • Authors: Jiaojiao Fang; Wei Wang; Cheng Zhu; Liang Fang; Junyang Jin; Yaru Ni; Chunhua Lu; Zhongzi Xu
      Pages: 100 - 107
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Jiaojiao Fang, Wei Wang, Cheng Zhu, Liang Fang, Junyang Jin, Yaru Ni, Chunhua Lu, Zhongzi Xu
      We herein report the triplet–triplet annihilation upconversion luminescence (TTA-UCL) clusters achieved by loading the platinum(II)-octaethylporphyrin (PtOEP) and 9,10-diphenylanthracene (DPA) into silica shells. This aqueous-based system possesses a core–shell structure which is of crucial importance for enhancing the mobility of core liquid. The encapsulated clusters with efficient green-to-blue upconversion without deoxygenation are conjoined with cadmium sulfide (CdS) as the photocatalyst. Platinum (Pt) is used to improve the separation of electron−hole pairs on the photocatalytic system. Given the band gap of photocatalysts, tetracycline (TC) degradation and photoinduced hydrogen evolution are used to perform the photocatalytic activity. CdS loaded with Pt has higher Pseudo-first-order rate constant (kpfo) in decomposing tetracycline than pure CdS. Moreover, the excellent hydrogen evolution property appears when the converted high energy photons from TTA-UCL-based clusters are introduced to the photocatalytic system. The quantum efficiency of hydrogen evolution increases further after the cocatalyst Pt deposition. This work not only fabricates an encapsulated structure for TTA-UCL clusters, but also provides an effective TTA-supported upconversion-photocatalysis system.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.069
      Issue No: Vol. 217 (2017)
       
  • Surface hydrogen bonds assisted meso-porous WO3 photocatalysts for high
           selective oxidation of benzylalcohol to benzylaldehyde
    • Authors: Yang Su; Zhongkang Han; Ling Zhang; Wenzhong Wang; Manyi Duan; Xiaoman Li; Yali Zheng; Yanggang Wang; Xiaoling Lei
      Pages: 108 - 114
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Yang Su, Zhongkang Han, Ling Zhang, Wenzhong Wang, Manyi Duan, Xiaoman Li, Yali Zheng, Yanggang Wang, Xiaoling Lei
      Selective photo–oxidation of alcohols displays high potential in solar energy conversion and reducing environmental pollution, yet its selectivity and conversion in aqueous phase is still far from expectation. Here we report a fluorinated meso-porous WO3 photocatalyst (Fm-WO3) exhibits significant selectivity (∼99%) and conversion (∼57%) in transforming benzylalcohol to benzaldehyde in the aqueous solution under the simulated sunlight irradiation. This high reactivity is attributed to the synergistic effect between meso-porous nanostructure and surface fluorination, where meso-porous structure supplies active sites to promote the multi–electron reduction of O2 and the surface fluorination assists the transmission of photogenerated holes. First–principles calculations further suggest that surface fluorination brings in an unoccupied impurity state in the band structure of WO3, which exhibits a strong correlation with the hydroxyl group of benzyalcohol and thus bridges the interaction between surfaces and alcohols. Meanwhile, the fluorination promotes the generation of OH by holes which can be considered as another way to oxidize benzyalcohol. Finally, a generalized reaction mechanism for selective photo-oxidation has been proposed.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.075
      Issue No: Vol. 217 (2017)
       
  • Heterostructured Ni/NiO composite as a robust catalyst for the
           hydrogenation of levulinic acid to γ-valerolactone
    • Authors: Song Song; Sikai Yao; Jiahui Cao; Lu Di; Guangjun Wu; Naijia Guan; Landong Li
      Pages: 115 - 124
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Song Song, Sikai Yao, Jiahui Cao, Lu Di, Guangjun Wu, Naijia Guan, Landong Li
      A non-precious metal catalyst Ni/NiO is developed for the efficient hydrogenation of levulinic acid to γ-valerolactone under mild conditions. Treating nickel oxide in hydrogen at controlled temperature of 473–573K results in its partial reduction to metallic nickel and the formation of Ni/NiO heterojunctions, as indicated by the characterization results from in situ XRD, XPS and TEM. The as-prepared Ni/NiO catalyst exhibits remarkable activity in levulinic acid hydrogenation with a high mass activity of 14.1mmol/h/g at 393K, being over 18 times higher than NiO and 10 times higher than metallic Ni. Besides, Ni/NiO shows very good stability and recyclability during the reaction, making it a promising catalyst for practical levulinic acid hydrogenation. The formation of Ni/NiO heterojunctions is crucial for the remarkable activity of Ni/NiO composite catalyst and a cooperative Langmuir-Hinshelwood mechanism is proposed for levulinic acid hydrogenation on the basis of kinetic analysis and theoretical calculations. The concept of cooperative catalysis on metal/oxide heterojunctions can be expanded to other hydrogenation reactions.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.073
      Issue No: Vol. 217 (2017)
       
  • Cage-based small-pore catalysts for NH3-SCR prepared by combining bulky
           organic structure directing agents with modified zeolites as reagents
    • Authors: Nuria Martín; Cecilia Paris; Peter N.R. Vennestrøm; Joakim R. Thøgersen; Manuel Moliner; Avelino Corma
      Pages: 125 - 136
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Nuria Martín, Cecilia Paris, Peter N.R. Vennestrøm, Joakim R. Thøgersen, Manuel Moliner, Avelino Corma
      It has been possible to efficiently synthesize high-silica ERI and AFX zeolites with nano-sized primary crystallites (30–200nm). This was achieved by using a dicationic and rigid organic structure directing agent (OSDA) that fits within the large cavities of these zeolites, and the use of FAU zeolites as initial Si- and Al-sources. Cu- and Fe-based ERI and AFX materials were prepared following both post-synthetic cation exchange and direct synthesis methodologies, showing good activity for the selective catalytic reduction (SCR) of nitrogen oxide using ammonia. Accelerated hydrothermal ageing of the zeolites at high temperature (i.e. 750°C) shows the necessity of removing the alkali cations remaining in the zeolites to obtain stable materials. Furthermore, the catalytic performance of the prepared Cu- and Fe-containing AFX catalysts, both before and after ageing treatment, approaches the catalytic activity of Cu- and Fe-CHA.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.082
      Issue No: Vol. 217 (2017)
       
  • Procyanidolic oligomers enhance photodegradation of chlorothalonil in
           water via reductive dechlorination
    • Authors: Pei Lv; Jun Zhang; Taozhong Shi; Leilei Dai; Xiangqiong Li; Xiangwei Wu; Xuede Li; Jun Tang; Yi Wang; Qing X. Li; Rimao Hua
      Pages: 137 - 143
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Pei Lv, Jun Zhang, Taozhong Shi, Leilei Dai, Xiangqiong Li, Xiangwei Wu, Xuede Li, Jun Tang, Yi Wang, Qing X. Li, Rimao Hua
      Chlorothalonil is an important broad-spectrum fungicide with an annual application rate of above ten thousands of tons of its active ingredient on agricultural crops world-wide. The effect of procyanidolic oligomers on photo degradation of chlorothalonil was investigated under sunlight and artificial lights. Procyanidolic oligomers enhanced photodegradation of chlorothalonil in paddy, reservoir, pond and distilled waters for 1.8, 4.6, 2.7 and 22.8 fold, respectively, relative to the procyanidolic oligomers free control. The mechanism was evidenced as a radical reduction reaction by electron paramagnetic resonance spectroscopy. Upon exposure to high-pressure mercury light, chlorothalonil produced 2,4,5-trichloro-1,3-dicyanobenzene, 2,5-dichloro-1,3-dicyanobenzene and 5-chloro-1,3-dicyanobenzene that were isolated, identified and characterized. Chlorothalonil underwent primarily step-wide photo reductive dechlorination in the presence of procyanidolic oligomers, which avoided the production of the highly toxic 4-hydroxy chlorothalonil. Procyanidolic oligomers possessed strong reductive property to photo reductive dechlorination. The results contributed to understanding of chlorothalonil phototransformation and high potential of using natural product procyanidolic oligomers as an additive to minimize aquatic toxicity and pollution of chlorothalonil.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.065
      Issue No: Vol. 217 (2017)
       
  • Trapped metallic cobalt nanoparticles in doped porous graphite: An
           electrocatalyst that gets better over reaction time
    • Authors: Guilherme M. Pereira; Thelma S.P. Cellet; Ricardo H. Gonçalves; Adley F. Rubira; Rafael Silva
      Pages: 144 - 153
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Guilherme M. Pereira, Thelma S.P. Cellet, Ricardo H. Gonçalves, Adley F. Rubira, Rafael Silva
      Hybrid materials synthesis is a pathway to integrating unstable inorganic phases in a protective matrix, as an approach to phase stabilization in harsh environments and to use the unique catalytic properties of such metastable phases. Here, we show a polymer precursor method to synthesize nitrogen-doped carbon nanomaterials from melamine-formaldehyde resin with Co2+ ions coordinated in the precursor material. Co2+ ions are reduced during the pyrolysis process to form metallic nanoparticles. Nitrogen-doped carbon nanotubes, with high nitrogen content, are obtained at pyrolysis temperature of 800°C or 900°C. When lower temperature is used (i.e. 700°C), porous amorphous carbon is obtained. At the highest temperature used (1000°C), carbon matrix with low nitrogen content is produced, having porous graphitic carbon structure. Graphitic carbon structure and metallic cobalt showed impressive catalytic activity toward water electrooxidation reaction, similar to benchmark catalysts for OER. The stability studies of the electrocatalyst showed an extraordinary 52% current density improvement in the first 8h of OER, and then a very stable pattern is verified. After 12h of applied potential, Tafel slope decreases to 57mVdec−1, which is characteristic of very fast surface kinetics, and therefore it is a promising material to become a reliable alternative to anode manufacture for OER.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.056
      Issue No: Vol. 217 (2017)
       
  • Nanostructured Fe2O3 dispersed on SiO2 as catalyst for high temperature
           sulfuric acid decomposition—Structural and morphological modifications
           on catalytic use and relevance of Fe2O3-SiO2 interactions
    • Authors: Ashish Nadar; Atindra Mohan Banerjee; M.R. Pai; S.S. Meena; R.V. Pai; R. Tewari; S.M. Yusuf; A.K. Tripathi; S.R. Bharadwaj
      Pages: 154 - 168
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Ashish Nadar, Atindra Mohan Banerjee, M.R. Pai, S.S. Meena, R.V. Pai, R. Tewari, S.M. Yusuf, A.K. Tripathi, S.R. Bharadwaj
      Through our previous studies it was established that non-precious Fe2O3 based catalyst has the potential to replace Pt based catalyst for high temperature sulfuric acid decomposition, the energy conversion step in iodine-sulfur or hybrid-sulfur thermochemical cycles for water splitting (Banerjee et al. [11] and [25]). However, issues like agglomeration and grain growth during prolonged operation still remains to be fully resolved. With an aim to develop low cost, abundant transition metal oxide catalyst with high activity and stability, Fe2O3 nanoparticles immobilized on SiO2 support is explored, anticipating that the Fe2O3-SiO2 interactions may prevent self agglomeration of Fe2O3 nanoparticles. Several catalysts with varying Fe2O3 content ranging from 5 to 20wt% were synthesized, characterized and their catalytic activity evaluated. Structural investigations by XRD and Mössbauer spectroscopy revealed that the 1000°C calcined samples contained ε-Fe2O3 as the major phase in addition to minor α and γ-Fe2O3 phases. ε-Fe2O3 were found to be dispersed as nanorods with typical width of 5nm from HRTEM images. Analysis of surface features by N2-BET surface area, pore size distribution, pore volume and XPS indicated that the majority of Fe2O3 was encapsulated within the mesoporous structure of SiO2 upto 15wt.%, beyond which Fe2O3 was deposited outside the porous network in an enhanced quantity. The surface area of Fe2O3(15wt.%)/SiO2 was found to be 99.6m2/g. Presence of Fe-O-Si linkages was confirmed by XPS, and supported by successive TPR/TPO studies. The extent of reducibility measured via TPR increased with increasing loading and was found to be maximum for the 15wt.% dispersed samples. The catalytic activity was found to increase with an increase in loading of active Fe2O3 content upto a SO2 yield of∼92% at 900°C at a WHSV of 27g acid g−1 h−1, for 15wt.% and then decreased. Further evaluation of the 15wt.% sample revealed the durability (100h) and practical applicability of the composition. The surface morphology, structure and composition underwent modifications during the 100h operation in order to adapt to the reaction environment (high temperature, steam, oxides of sulfur) and the Fe2O3 (15wt.%)/SiO2 catalyst exhibited iron sulfate formation and significant surface reorganization. The high catalytic activity can be ascribed to nanoparticulate nature of Fe2O3 and stability due to its anchored structure on SiO2. These findings would inspire the design of active and stable catalyst for high temperature catalytic reactions.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.045
      Issue No: Vol. 217 (2017)
       
  • Core-shell g-C3N4@ZnO composites as photoanodes with double synergistic
           effects for enhanced visible-light photoelectrocatalytic activities
    • Authors: Jian Wang; Zhuang Yang; Xingxing Gao; Wenqing Yao; Weiqin Wei; Xianjie Chen; Ruilong Zong; Yongfa Zhu
      Pages: 169 - 180
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Jian Wang, Zhuang Yang, Xingxing Gao, Wenqing Yao, Weiqin Wei, Xianjie Chen, Ruilong Zong, Yongfa Zhu
      In this work, core-shell g-C3N4@ZnO photocatalysts were facilely synthesized via a reflux method applying the industrial grade ZnO nanoparticles and g-C3N4 nanosheets as the starting materials. The thickness of the g-C3N4 shell was gradually increased with the increasing proportion of g-C3N4 and the average thickness of the coating g-C3N4 is 1.89nm and 3.21nm for a weight ratio of 15% and 20% (g-C3N4/ZnO) g-C3N4@ZnO composites, respectively. By using g-C3N4@ZnO composites as photoanodes for the first time, 15% g-C3N4@ZnO photoanode exhibits the best PEC performance for the degradation of phenol under visible light irradiation with an anodic bias of 1.5V vs. SCE and the rate constant is determined to be 1.216h−1, which is almost 2.1 times as high as that of 20% g-C3N4@ZnO photoanode. The enhancement of the visible light PEC degradation phenol is attributed to the double synergistic effects which combined of special core-shell nanostructures and electro-oxidation assisted photocatalysis. This work not only demonstrates core-shell g-C3N4@ZnO composites as a promising photoanode for the utilization of solar conversion, but also meets the requirement for the increasing demand of practical applications
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.034
      Issue No: Vol. 217 (2017)
       
  • Simultaneous photocatalytic removal of nitrate and oxalic acid over
           Cu2O/TiO2 and Cu2O/TiO2-AC composites
    • Authors: Haruna Adamu; Alan J. McCue; Rebecca S.F. Taylor; Haresh G. Manyar; James A. Anderson
      Pages: 181 - 191
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Haruna Adamu, Alan J. McCue, Rebecca S.F. Taylor, Haresh G. Manyar, James A. Anderson
      Cu2O/TiO2 (1–10wt% Cu2O) and 2.5% Cu2O/TiO2-AC (2.5–20wt% AC) photocatalyst composites were synthesised by an ethanol reduction method. The materials were characterised by a number of techniques which confirmed the presence of Cu2O in contact with the TiO2. Pure TiO2 alone was not active for the simultaneous photocatalytic removal of nitrate and oxalic acid under conditions employed, however, photocatalytic activity was observed for TiO2 and TiO2/AC in the presence of Cu2O. This may have resulted from suppression of charge recombination via creation of a p-n heterojunction between Cu2O and TiO2. Within the series, 2.5% Cu2O/TiO2 exhibited the best photocatalytic performance with 57.6 and 99.8% removal of nitrate and oxalic acid, respectively, with selectivities of 45.7, 12.4 and 41.9% to NH4 +, NO2 − and N2, respectively after 3h. For the carbon containing photocatalysts, 2.5% Cu2O/TiO2-2·5AC displayed the highest activity with 42.5 and 96.6% removal of nitrate and oxalic acid, respectively, with 32.7, 11.6 and 55.7% selectivities to NH4 +, NO2 − and N2, respectively. The highest AC loading tested resulted in selectivity to NH4 + of 21.6 with no NO2 − detected, together with an improved N2 selectivity (78.4%) albeit at lower (12.7%) nitrate conversion. Data suggests that Cu2O/TiO2 can be used in the photocatalytic reduction of nitrate and improved selectivity towards N2 can be attained by influencing factors which control the relative rate of oxalic acid consumption.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.091
      Issue No: Vol. 217 (2017)
       
  • Enhanced activity and durability of the oxygen reduction catalysts
           supported on the surface expanded tubular-type carbon nanofiber
    • Authors: Jiyoung Kim; Ui-Su Im; Dong-Hyun Peck; Seong-Ho Yoon; Ho Seok Park; Doo-Hwan Jung
      Pages: 192 - 200
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Jiyoung Kim, Ui-Su Im, Dong-Hyun Peck, Seong-Ho Yoon, Ho Seok Park, Doo-Hwan Jung
      Tubular type carbon nanofibers (TCNFs) are prepared and used as a catalyst support material for a cathode electrode of low temperature fuel cells through structural modification. The pristine TCNF is treated by graphitization and makes partially torn-tube shape through the surface expansion by rapid thermal treatment of the oxidized graphitized TCNF. Physical properties of the TCNF group are examined, and it is confirmed that the unique ripped texture along fiber axis with graphitic structure is obtained by the surface expansion. Platinum catalysts supported on these TCNF group are prepared and evaluated. Electrochemical properties are examined via cyclic voltammograms and polarization curves for oxygen reduction reaction activity. The platinum catalyst on the surface expanded TCNF has the enhanced activity at initial and the stable performance even after accelerated durability test due to their unique structure.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.093
      Issue No: Vol. 217 (2017)
       
  • Alloy vs. intermetallic compounds: Effect of the ordering on the
           electrocatalytic activity for oxygen reduction and the stability of low
           temperature fuel cell catalysts
    • Authors: Ermete Antolini
      Pages: 201 - 213
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Ermete Antolini
      The application of intermetallic compounds in heterogeneous catalysis had a significant boost during the last decade. Notwithstanding the advantages related to the use of intermetallics in catalysis, random alloys, more easy to prepare, are commonly used as catalysts in low temperature polymer electrolyte membrane fuel cells (LT-PEMFC). In various papers, however, the use of Pt- and Pd-based intermetallics in LT-PEMFCs is reported. In this work an overview of the effect of the crystal structure ordering on the activity for oxygen reduction and stability of fuel cell catalysts is discussed, by comparing ordered and disordered structures with the same A/M (A=Pt, Pd; M=first row transition metal) atomic ratio and ordered structures with different A content.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.081
      Issue No: Vol. 217 (2017)
       
  • Sub-stoichiometric titanium oxide as a new anode material for
           electro-Fenton process: Application to electrocatalytic destruction of
           antibiotic amoxicillin
    • Authors: Nihal Oturan; Soliu O. Ganiyu; Stephane Raffy; Mehmet A. Oturan
      Pages: 214 - 223
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Nihal Oturan, Soliu O. Ganiyu, Stephane Raffy, Mehmet A. Oturan
      This study report, for the first time, the potential use of sub-stoichiometric titanium oxide (Ti4O7) elaborated by plasma deposition, as an efficient, stable and cost-effective anode material for electrocatalytic oxidation of organic pollutants by electro-Fenton process. The antibiotic amoxicillin (AMX) was selected as target pollutant and the oxidative degradation of this drug was ensured by hydroxyl radicals generated both at Ti4O7 surface by oxidation of water and in the bulk solution from electrocatalytically produced Fenton’s reagent. A quick oxidation of 0.1mM (36.5mgL ̶1) AMX was obtained in a short electrolysis time for all applied current studied while its almost complete mineralization was attained even at a low current intensity of 120mA. The performance of this new anode material in term of degradation kinetics, mineralization current efficiency (MCE) and energy cost was compared with boron doped diamond (BDD) and other conventional anodes such as platinum (Pt) and dimensional stable anode (DSA). Results showed that Ti4O7 provides similar oxidation rate and MCE as BDD at all current studies, while it give significantly better results than DSA and Pt anodes. The solutions treated by electro-Fenton process using Ti4O7 anode showed low percentage bioluminescence inhibition to V. fischeri bacteria, indicating excellent detoxification of the AMX solution. Therefore, Ti4O7 anode appears to be an interesting cost-effective alternative anode material to BDD and other industrial electrodes for electro-Fenton processes since its production is very inexpensive when compared to BDD.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.062
      Issue No: Vol. 217 (2017)
       
  • In situ fabrication of Bi2O2CO3/MoS2 on carbon nanofibers for efficient
           photocatalytic removal of NO under visible-light irradiation
    • Authors: Jundie Hu; Dongyun Chen; Najun Li; Qingfeng Xu; Hua Li; Jinghui He; Jianmei Lu
      Pages: 224 - 231
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Jundie Hu, Dongyun Chen, Najun Li, Qingfeng Xu, Hua Li, Jinghui He, Jianmei Lu
      A novel nanocomposite photocatalyst for NO removal, Bi2O2CO3-MoS2-CNFs, was fabricated by an efficient method. This new photocatalyst performed impressively in the removal of NO at low concentration (600ppb), with a maximum efficiency of 68% under visible-light irradiation, superior to most other visible-light photocatalysts. Its high performance was ascribed to the introduction of carbon nanofibers as carriers, and MoS2, which enhanced the absorption of visible light and accelerated the separation and transfer of electrons and holes. Photocurrent tests and electrochemical impedance spectroscopy also demonstrated that Bi2O2CO3-MoS2-CNFs had a high efficiency of interfacial charge separation, which is critical to improving the photocatalytic activity. Moreover, the membrane of the photocatalyst was stable and recyclable after multiple runs. All of these factors demonstrate its potential application in the removal of NO from air.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.088
      Issue No: Vol. 217 (2017)
       
  • Constructing efficient solar light photocatalytic system with
           Ag-introduced carbon nitride for organic pollutant elimination
    • Authors: Xi Wu; Changhai Lu; Jingjie Liu; Shaoqing Song; Chuanzhi Sun
      Pages: 232 - 240
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Xi Wu, Changhai Lu, Jingjie Liu, Shaoqing Song, Chuanzhi Sun
      Owing to the unique electronic and optical properties, carbon nitride (CN) materials have attracted widespread interest for photocatalytic application in the field of environment and energy. However, low carrier mobility and insufficient sunlight absorption limit the efficient application, which is attributed to the planar hydrogen bonding between strands of polymeric melon units with NH/NH2. Herein, Ag-introduced CN (AgCN) samples were designed as photocatalysts by introducing Ag into CN to weaken the planar hydrogen bonding for photocatalytically eliminating methyl orange pollutant. Spectroscopy, electrochemistry and computational studies revealed that AgCN photocatalyts presented a significantly enhanced sunlight absorption, efficient carrier mobility as well as improved O2 adsorption state. As a result, photoreactivity for methyl orange photooxidation elimination over AgCN was significantly enhanced, with apparent rate of 0.13min−1 for optimal AgCN-4 under visible-light irradiation, which was 6.50, 8.13, 2.60, and 4.33 times that of Bi2WO6, BiOCl, Ag/CN, and Ag2CO3, respectively. The result supplied an efficient approach for constructing effective visible-light-irradiation photocatalysts for environmental purification.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.06.001
      Issue No: Vol. 217 (2017)
       
  • Crystal growth of titania by photocatalytic reaction
    • Authors: Hiromasa Nishikiori; Shunpei Fujiwara; Syuhei Miyagawa; Nobuyuki Zettsu; Katsuya Teshima
      Pages: 241 - 246
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Hiromasa Nishikiori, Shunpei Fujiwara, Syuhei Miyagawa, Nobuyuki Zettsu, Katsuya Teshima
      Substrate plates coated with anatase-type titania thin films were immersed in a solution of titanium (IV) chloride and lithium nitrate at 353K during UV irradiation. About 20 nm-sized anatase-type titania crystals were formed on the original titania film consisting of almost the same sized particles. Nitrate ions in the solution were reduced to nitrite ions, and water was transformed into hydroxide ions by a photocatalytic reaction on the original titania film. The pH value increased on the titania surface, which caused the titanium hydroxide formation. The titanium hydroxide was then dehydrated and transformed into titania. The titania particles formed on the substrate exhibited a photocatalytic activity similar to the original titania.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.076
      Issue No: Vol. 217 (2017)
       
  • Low-temperature methanol dehydration to dimethyl ether over various
           small-pore zeolites
    • Authors: Dilshad Masih; Sohrab Rohani; Junko N. Kondo; Takashi Tatsumi
      Pages: 247 - 255
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Dilshad Masih, Sohrab Rohani, Junko N. Kondo, Takashi Tatsumi
      Eight-membered ring small-pore zeolites Rho and KFI have been synthesized, characterized and tested for dehydration of methanol to dimethyl ether at low-temperature, and compared with other zeolites and three different samples of γ-Al2O3. Both the zeolites were mainly crystallized from the synthesis gels with the Si/Al ratio of 5.0 by a conventional hydrothermal method without any agitation. The amount of total solid-acid sites was 1.65mmolg−1 and 2.53mmolg−1 for zeolite KFI and Rho, respectively. In addition, zeolites SSZ-13, RUB-13, and ZSM-5 were also employed for the reaction. Reaction conditions were optimized for a low-temperature catalytic dehydration of methanol selectively to dimethyl ether. Methanol dehydration efficiency of various zeolitic frameworks is discussed against the strength of solid-acidity, type of channel structure, specific surface area, and particle size. At temperatures≤200°C, the overall catalytic efficiency of the small-pore zeolites with appropriate medium-strong acidity and 3-D channels was superior to that of the reference γ-Al2O3 materials.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.089
      Issue No: Vol. 217 (2017)
       
  • Highly enhanced photocatalytic activity of CaSn(OH)6 through tuning
           CaSn(OH)6/SnO2 heterostructural interaction and optimizing Fe3+ doping
           concentration
    • Authors: Tongyao Liu; Xinlong Ma; Linfen Yang; Hao Li; Huihui Li; Soo Wohn Lee; Yuhua Wang
      Pages: 256 - 264
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Tongyao Liu, Xinlong Ma, Linfen Yang, Hao Li, Huihui Li, Soo Wohn Lee, Yuhua Wang
      A series of novel CaSn(OH)6/SnO2 heterostructure (CSH) photocatalysts have been synthesized via a facile one-pot hydrothermal process with different molar ratios of raw materials. The obtained CaSn(OH)6/SnO2 composite with CaCl2:SnCl4 =0.8 (0.8CSH) exhibits outstanding ultraviolet (UV)-light photocatalytic activity, which could be attributed to the efficient separation of photogenerated electrons and holes. Meanwhile, the doping of Fe3+ ions into 0.8CSH substrate greatly enhances the UV and visible-light photocatalytic activities, and the photodegradation rate of 1.0mol% Fe-doped CSH (1.0FCSH) sample exceeds that of 0.8CSH by a factor of more than 14 times. This could be attributed to the fact that Fe-doping induces the shift of the absorption edge into the visible light region and reduces the recombination of electron-hole pairs. Overall, this research can provide an effective approach to synthesize new efficient photocatalysts and facilitate their application in environmental protection.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.080
      Issue No: Vol. 217 (2017)
       
  • Carbon supported Ru-Ni bimetallic catalysts for the enhanced one-pot
           conversion of cellulose to sorbitol
    • Authors: Lucília S. Ribeiro; Juan J. Delgado; José J.M. Órfão; M. Fernando R. Pereira
      Pages: 265 - 274
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Lucília S. Ribeiro, Juan J. Delgado, José J.M. Órfão, M. Fernando R. Pereira
      Ru and Ni mono- and bimetallic catalysts were prepared by impregnation of two different supports (activated carbon and carbon nanotubes) and were characterized by TPR, TEM and N2 adsorption at −196°C. The prepared Ru mono- and bimetallic catalysts were highly efficient for the hydrolytic hydrogenation of cellulose to sorbitol. Regardless of the support used, when nickel was incorporated into the supported ruthenium catalyst a promoting effect was observed, with an increase in both conversion and selectivity to sorbitol, which was explained by the interaction between both metals. Yields of sorbitol around 50–60% were achieved after 5h of reaction when using Ru-Ni/AC and Ru-Ni/CNT as catalysts. Moreover, a yield of sorbitol over 70% could be reached in just 1h of reaction if the Ru-Ni catalysts were ball-milled together with cellulose.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.04.078
      Issue No: Vol. 217 (2017)
       
  • Two-dimensional germanium monochalcogenides for photocatalytic water
           splitting with high carrier mobility
    • Authors: Xingshuai Lv; Wei Wei; Qilong Sun; Fengping Li; Baibiao Huang; Ying Dai
      Pages: 275 - 284
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Xingshuai Lv, Wei Wei, Qilong Sun, Fengping Li, Baibiao Huang, Ying Dai
      Highly efficient utilization of solar energy to split water into hydrogen and oxygen is regarding as a promising strategy to deal with the future energy crisis and environmental problems. To explore highly efficient and low-cost photocatalysts is highly desired. Herein, phosphorene-like germanium monochalcogenides (GeS and GeSe monolayers) are proposed here as efficient photocatalysts for water splitting. After confirming their stabilities, we observe that GeS exhibits an indirect band gap of 2.29eV while GeSe reveals a direct band gap of 1.59eV by HSE hybrid functional. Remarkably, high and directionally anisotropic carrier mobilities (2430.50cm2 V−1 s−1 for GeS and 4032.64cm2 V−1 s−1 for GeSe) are quantitatively investigated by using deformation potential theory. In addition, GeS and GeSe monolayers exhibit a good separation of electrons and holes, which effectively reduces the photocatalytic activity with high efficiency. Upon the application of strain, the band structure can be modulated from semiconductor to metal and a direct-indirect bandgap transition is observed. Most intriguingly, the band gaps and band edge alignments at certain pH value can be effectively tuned to meet the requirement of the redox potential in water splitting. Finally, the adsorption and decomposition of water molecules on the surface of 2D GeS and the subsequent formation of hydrogen were explored, which unravels the mechanism of photocatalytic hydrogen production on 2D GeS. Our findings will be valuable for facilitating the exploration and application of GeS and GeSe for photocatalytic water splitting.
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      PubDate: 2017-06-07T07:27:20Z
      DOI: 10.1016/j.apcatb.2017.05.087
      Issue No: Vol. 217 (2017)
       
  • Black phosphorus: A promising two dimensional visible and
           near-infrared-activated photocatalyst for hydrogen evolution
    • Authors: Mingshan Zhu; Yasuko Osakada; Sooyeon Kim; Mamoru Fujitsuka; Tetsuro Majima
      Pages: 285 - 292
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Mingshan Zhu, Yasuko Osakada, Sooyeon Kim, Mamoru Fujitsuka, Tetsuro Majima
      The search for active photocatalysts that directly split water to hydrogen (H2) under visible and near-infrared (NIR) light irradiation remains one of the most challenging tasks for solar energy utilization. Here we report that two dimensional (2D) black phosphorus (BP) nanoflakes can harness visible and NIR light for H2 evolution. In the presence of reduced graphene oxide and Pt nanoparticles, ca. 5.13 and 1.26μmol H2 were obtained after excited BP nanoflakes under >420nm and >780nm irradiation for 4h, respectively. The apparent quantum efficiencies (AQEs) were as high as approximately 8.7% at 420±5nm (visible) and 1.5% at 780±5nm (NIR), respectively. These results indicate that 2D BP can be used as visible- and NIR-activated elemental photocatalyst in artificial photosynthesis and renewable energy conversion.
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      PubDate: 2017-06-12T03:24:18Z
      DOI: 10.1016/j.apcatb.2017.06.002
      Issue No: Vol. 217 (2017)
       
  • Three-dimensional interconnected mesoporous anatase TiO2 exhibiting unique
           photocatalytic performances
    • Authors: Weiyang Dong; Youwei Yao; Li Li; Yaojun Sun; Weiming Hua; Guoshun Zhuang; Dongyuan Zhao; Shuwen Yan; Weihua Song
      Pages: 293 - 302
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Weiyang Dong, Youwei Yao, Li Li, Yaojun Sun, Weiming Hua, Guoshun Zhuang, Dongyuan Zhao, Shuwen Yan, Weihua Song
      In this article, an ordered two-dimensional (2D) hexagonal mesoporous anatase crystals–silica nanocomposite was first synthesized using synchronous-assembly of surfactant and inorganic precursors molecules, and then a three-dimensional (3D) interconnected mesoporous anatase TiO2 was prepared via an “extracting silica” approach. The results show that the mesopore channels in our titania are highly connected by plenty of 3D uniform intrawall mesopores while retaining mesostructural integrity and regularity. The TiO2 prepared is completely anatase crystalline with uniform nanocrystals (13.0nm in size) and a high specific surface area (∼145m2/g). This method is mild, simple and can be easily repeatable. The photocatalytic degradation rates of Acid Red 1 (0.173min−1) and microcystin−LR (2.57min−1) on the interconnected mesoporous TiO2 are very high, which are 41.6 and 2.85 times higher than that of the parent sample; 29.2 and 7.20 times that of P25 photocatalyst, respectively. These results clearly demonstrated that the 3D interconnected mesostructure played a key role in the activity increments. In addition, our photocatalysts are considerably stable and reusable. To the best of our knowledge, such results have not been seen in the literature before. Furthermore, the fundamentals of this study would provide new insights for the rational design and preparation of 3D highly interlinked mesoporous metal-oxides with unique photocatalytic performances.
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      PubDate: 2017-06-12T03:24:18Z
      DOI: 10.1016/j.apcatb.2017.05.083
      Issue No: Vol. 217 (2017)
       
  • Key factors improving oxygen reduction reaction activity in cobalt
           nanoparticles modified carbon nanotubes
    • Authors: Atsushi Gabe; Jaime García-Aguilar; Ángel Berenguer-Murcia; Emilia Morallón; Diego Cazorla-Amorós
      Pages: 303 - 312
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Atsushi Gabe, Jaime García-Aguilar, Ángel Berenguer-Murcia, Emilia Morallón, Diego Cazorla-Amorós
      Multiwall carbon nanotubes (CNTs) decorated with cobalt oxide (CoOx) nanoparticles (NPs) are prepared in various synthesis conditions to investigate their capability as oxygen reduction reaction (ORR) catalysts for fuel cells in alkaline media. The synthesis conditions include the use of protecting, reducing or complexing agents and heat treatment. Higher ORR activity is possible for smaller size of Co NPs catalysts due to the enlarged interfaces between Co species and CNTs. The addition of polyvinylpyrrolidone (PVP) as protecting agent and NaBH4 during the preparation procedure is necessary for obtaining the highest activity since it favors the formation of lower oxidation states for Co species and the incorporation of N groups which improve ORR activity. CNTs loaded with only 1wt.% of Co NPs prepared by a facile method using PVP, NaBH4 and subsequent heat treatment at 500°C under N2 atmosphere, demonstrates both similar catalytic activity and stability than Pt/Vulcan (20wt.% Pt on Vulcan). The synergic chemical coupling effects between CNTs and CoOx NPs and the presence of carbon material with pyridinic N and quaternary N groups formed from the protecting agent decomposition, seem to be the main factors responsible for the remarkable electrocatalytic activity.
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      PubDate: 2017-06-12T03:24:18Z
      DOI: 10.1016/j.apcatb.2017.05.096
      Issue No: Vol. 217 (2017)
       
  • Morphology control of noble metal catalysts from planar to dendritic
           shapes by galvanic displacement
    • Authors: Seungyeon Baek; Kwang Hwan Kim; Myung Jun Kim; Jae Jeong Kim
      Pages: 313 - 321
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Seungyeon Baek, Kwang Hwan Kim, Myung Jun Kim, Jae Jeong Kim
      Noble metal electrocatalysts can simply be prepared via galvanic displacement method on a sacrificial substrate, which is advantageous for preparing a uniform and thin catalyst layer. However, it is difficult to control the morphology of deposited metals via galvanic displacement, therefore, there is a limitation to increase the surface area of electrocatalysts. In this study, we demonstrate galvanic displacement for controlling the morphology of Pd, Pt, and Au from planar to whisker shapes by manipulating the dissolution rate of the sacrificial Cu substrate and the mass transport of noble metal ions. The acceleration of the dissolution of sacrificial substrate increases the reduction rate of noble metal, which develops a steep concentration gradient of noble metal ions near the surface of substrate. This induces the selective deposition of noble metal to form a whisker instead of smooth film. To verify the advantage of whisker-type catalysts, the ethanol oxidation with Pd is investigated. Whisker-type Pd shows 21 times higher electrocatalytic performance than planar Pd due to larger surface area. Therefore, it can be suggested that whisker-type catalysts simply prepared by galvanic displacement is applicable for various electrocatalytic reactions.
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      PubDate: 2017-06-12T03:24:18Z
      DOI: 10.1016/j.apcatb.2017.05.094
      Issue No: Vol. 217 (2017)
       
  • Porous graphitic carbon nitride nanosheets prepared under self-producing
           atmosphere for highly improved photocatalytic activity
    • Authors: Xueping Song; Qin Yang; Xiaohui Jiang; Mengyun Yin; Limei Zhou
      Pages: 322 - 330
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Xueping Song, Qin Yang, Xiaohui Jiang, Mengyun Yin, Limei Zhou
      The reaction atmosphere employed in graphitic carbon nitride (gC3N4) synthesis can play an important role in modifying the electronic structure and the properties of photoexcited charge carriers and consequently the photocatalytic activity of semiconductor photocatalysts. By controlling the entrance of N2 in the preparation of gC3N4, we introduced pyrolysis-generated self-producing atmosphere. Under the homogeneous self-producing atmosphere and without any other additives, we fabricated porous gC3N4 with more uncondensed amino groups. These formed pores endow gC3N4 nanosheets with more exposed active edges and cross-plane diffusion channels that greatly speed up mass and charge carrier transfer. Furthermore, the uncondensed amino groups within the structure could promote the dispersion behavior of samples in water and induce the structure distortion of gC3N4 layers through the strong hydrogen bonding interactions between layers and thus decease the distance of interlayers. Enhanced photocatalytic activity is seen as well from a drastic increase in the degradation of rhodamine B (RhB) dye. This work provides a simple and efficient strategy for fabricating porous texture and realizing the tunable structure distortion of g-C3N4 layers to adjust its electronic structure and photocatalysis.
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      PubDate: 2017-06-12T03:24:18Z
      DOI: 10.1016/j.apcatb.2017.05.084
      Issue No: Vol. 217 (2017)
       
  • Pt–WOx on monoclinic or tetrahedral ZrO2: Crystal phase effect of
           zirconia on glycerol hydrogenolysis to 1,3-propanediol
    • Authors: Yiqiu Fan; Shijie Cheng; Hao Wang; Jing Tian; Songhai Xie; Yan Pei; Minghua Qiao; Baoning Zong
      Pages: 331 - 341
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Yiqiu Fan, Shijie Cheng, Hao Wang, Jing Tian, Songhai Xie, Yan Pei, Minghua Qiao, Baoning Zong
      The effects of the crystal phases of ZrO2 in the Pt–WO x /ZrO2 catalysts on glycerol hydrogenolysis to 1,3-propanediol (1,3-PDO) were comparatively studied. Pt and WO x were sequentially deposited on monoclinic (m-ZrO2) and tetragonal (t-ZrO2) ZrO2 supports with similar surface areas by the wetness impregnation method. On both catalysts, sub-nanosized Pt particles were well dispersed on the supports, and the WO x species were mainly in the monomeric state and partly covered the Pt particles. The Pt–WO x /m-ZrO2 catalyst had larger Pt particle size and less Brønsted acid sites than the Pt–WO x /t-ZrO2 catalyst. In glycerol hydrogenolysis, the glycerol conversion and 1,3-PDO selectivity on the Pt–WO x /m-ZrO2 catalyst were less than one half of those on the Pt–WO x /t-ZrO2 catalyst. The Pt–WO x /t-ZrO2 catalyst exhibited a high 1,3-PDO yield of 49.4%, an excellent 1,3-PDO productivity of 5.10ggPt −1 h−1, and good recyclability. The superiority of the Pt–WO x /t-ZrO2 catalyst in glycerol hydrogenolysis to 1,3-PDO is attributed to the better synergy between smaller Pt particles in affording hydrogen atoms and more Brønsted acid sites in converting glycerol to the intermediate suitable for the formation of 1,3-PDO.
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      PubDate: 2017-06-12T03:24:18Z
      DOI: 10.1016/j.apcatb.2017.06.011
      Issue No: Vol. 217 (2017)
       
  • Photocatalytic hydrogen production over Aurivillius compound Bi3TiNbO9 and
           its modifications by Cr/Nb co-doping
    • Authors: Lu Jiang; Shuang Ni; Gang Liu; Xiaoxiang Xu
      Pages: 342 - 352
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Lu Jiang, Shuang Ni, Gang Liu, Xiaoxiang Xu
      In this work, we have applied Cr/Nb co-doping strategy to the wide band gap semiconductor Bi3TiNbO9 and have performed a detailed investigation on the structure, optical and photocatalytic properties of these modified Aurivillius compounds Bi3Ti1-2xCrxNb1+xO9 (x=0, 0.1, 0.2, 0.3). Our results suggest that Cr/Nb doping slightly expand the unit cell of Bi3TiNbO9 with a doping limit around 20%. The involvement of Cr/Nb dopants in the crystal structure significantly reduces the band gap of Bi3TiNbO9 by nearly 1eV. Photocatalytic experiments and photoelectrochemical measurements confirms the critical role of Cr/Nb dopants in improving photocatalytic hydrogen production and anodic photocurrent. More than two-fold enhancement in hydrogen production has been noticed for merely 10% Cr/Nb co-doping. The highest photocatalytic activity belongs to Bi3Ti0.8Cr0.1Nb1.1O9 (x=0.1) for full range illumination and to Bi3Ti0.6Cr0.2Nb1.2O9 (x=0.2) for visible light illumination, with apparent quantum efficiency (AQE) approaching 0.52% and 0.27%, respectively. DFT calculation discloses the role of Cr in forming a new valence band inside the band gap of Bi3TiNbO9. In addition, strong anisotropic phenomenon in charge transportation of Bi3TiNbO9 is also verified by DFT, as both conduction band minimum (CBM) and valence band maximum (VBM) are buried in the [BiTiNbO7]2− perovskite slabs and charges are only allowed to migrate within the slabs.
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      PubDate: 2017-06-12T03:24:18Z
      DOI: 10.1016/j.apcatb.2017.06.012
      Issue No: Vol. 217 (2017)
       
  • Thermocatalytic conversion of lignin in an ethanol/formic acid medium with
           NiMo catalysts: Role of the metal and acid sites
    • Authors: Mikel Oregui-Bengoechea; Inaki Gandarias; Nemanja Miletić; Sveinung F. Simonsen; Audun Kronstad; Pedro L. Arias; Tanja Barth
      Pages: 353 - 364
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Mikel Oregui-Bengoechea, Inaki Gandarias, Nemanja Miletić, Sveinung F. Simonsen, Audun Kronstad, Pedro L. Arias, Tanja Barth
      NiMo catalysts supported on different sulfated and non-sulfated aluminas and zirconias were studied for the catalytic conversion of lignin in a formic acid/ethanol medium. All the pre-reduced NiMo-support combinations resulted in high conversion of lignin into bio-oil, with over 60% yield (mass%). The NiMo-sulfated alumina catalyst exhibited the highest activity among all the catalysts studied. The overall reaction mechanism of the catalytic lignin conversion was found to be especially complex. The oil yield and its properties are affected by a combination of successive catalytic reactions that are part of the lignin conversion process. Lignin is first de-polymerized into smaller fragments through the cleavage of the aliphatic ether bonds. This reaction can be either catalyzed by Ni0 species and strong Lewis acid sites within the alumina supports. In the presence of both active species, the Ni0 catalyzed ether bond cleavage is the prevailing reaction mechanism. In a second step, the smaller lignin fragments can be stabilized by catalytic hydrodeoxygenation (HDO) and alkylation reactions that hinder their re-polymerization into char. Mo was found to be especially active for HDO reactions while all the catalysts studied exhibited significant alkylation activity. The final bio-oil yield is strongly dependent on the aliphatic ether bond cleavage rate; the contribution of those monomer stabilization reactions (i.e. HDO and alkylation) being secondary.
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      PubDate: 2017-06-12T03:24:18Z
      DOI: 10.1016/j.apcatb.2017.06.004
      Issue No: Vol. 217 (2017)
       
  • V2O5-WO3/TiO2 catalysts under thermal stress: Responses of structure and
           catalytic behavior in the selective catalytic reduction of NO by NH3
    • Authors: Patrick G.W.A. Kompio; Angelika Brückner; Frank Hipler; Olga Manoylova; Gerhard Auer; Gerhard Mestl; Wolfgang Grünert
      Pages: 365 - 377
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Patrick G.W.A. Kompio, Angelika Brückner, Frank Hipler, Olga Manoylova, Gerhard Auer, Gerhard Mestl, Wolfgang Grünert
      V2O5-WO3/TiO2 catalysts of compositions typically used in SCR applications were subjected to calcinations in air at temperatures between 873K and 1023K for different durations, starting from a mildly calcined state in which species structure originating from wet preparation had been fixed by calcination at 623K for 1h. After calcination, samples were examined with respect to their SCR activity and to structural changes by nitrogen physisorption, XRD, Raman spectroscopy, EPR, temperature-programmed reduction, XPS and Low-Energy Ion Scattering (LEIS). Driven by loss of BET surface area, samples exhibited a complex behavior with up to three well-separated maxima of SCR activity before final deactivation. While the first of these maxima depended on the calcination rate (temperature), the other two maxima occurred at specific ranges of the BET surface area. During calcination, tungstate was segregated from the support surface forming WO3 under more severe conditions. Observations in the EPR spectra are in conflict with assignments of observed SCR activities to isolated vanadate sites. Assuming major contributions of dimeric vanadate to the catalytic performance, a model was proposed, which explains the first two activity maxima while the origin of the third one remains to be elucidated. In this model, segregation of tungstate results in formation of active V-O-V structures from less active isolated vanadate species previously separated by excessive amounts of tungstate. The main role of tungstate is to provide optimum sizes of vanadate ensembles, but a direct favorable influence of tungstate on vanadate is not excluded.
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      PubDate: 2017-06-12T03:24:18Z
      DOI: 10.1016/j.apcatb.2017.06.006
      Issue No: Vol. 217 (2017)
       
  • Fabrication of two lanthanides co-doped Bi2MoO6 photocatalyst: Selection,
           design and mechanism of Ln1/Ln2 redox couple for enhancing photocatalytic
           activity
    • Authors: Hongda Li; Wenjun Li; Fangzhi Wang; Xintong Liu; Chaojun Ren
      Pages: 378 - 387
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Hongda Li, Wenjun Li, Fangzhi Wang, Xintong Liu, Chaojun Ren
      Various Lna/Lnb co-doped bismuth molybdate (Bi2MoO6) photocatalysts were synthesized by a hydrothermal process. The result of photocatalytic experiment demonstrated that the relevant Ln1 3+ 4f7+x /Ln2 3+ 4f7−x (Ln1/Ln2 =Tb/Eu, Dy/Sm, Er/Nd; x=1, 2, 4) co-doped Bi2MoO6 samples shows higher photocatalytic activities. Moreover, all the photocatalytic activities of Ln1/Ln2 co-doped Bi2MoO6 were higher than that of the corresponding single-doped Bi2MoO6. The crystalline structures, morphology, constituent contents, chemical state and optical properties of the samples were analyzed in detail. Meanwhile, a new conjecture about the complementary distribution of 4f orbital electrons in the Ln1/Ln2 redox couple was proposed through co-doping with Ln1 and Ln2 ions to improve the photocatalytic activity of Bi2MoO6. For the Bi2MoO6 photcatalyst, Dy/Sm co-doping displayed the strongest photocurrent response as well as the best photocatalytic activity, while Tb/Eu co-doping displayed the apparently extended visible-light absorption region. These findings provides a novel strategy to fabricate and engineer high-efficiency photocatalysts by selecting appropriate Ln1/Ln2 redox couple.
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      PubDate: 2017-06-12T03:24:18Z
      DOI: 10.1016/j.apcatb.2017.06.015
      Issue No: Vol. 217 (2017)
       
  • Doping of graphitic carbon nitride for photocatalysis: A reveiw
    • Authors: Longbo Jiang; Xingzhong Yuan; Yang Pan; Jie Liang; Guangming Zeng; Zhibin Wu; Hou Wang
      Pages: 388 - 406
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Longbo Jiang, Xingzhong Yuan, Yang Pan, Jie Liang, Guangming Zeng, Zhibin Wu, Hou Wang
      As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has been the hotspot in the materials science as a metal-free and visible-light-responsive photocatalyst. Pure g-C3N4 suffers from the insufficient sunlight absorption, low surface area and the fast recombination of photo-induced electron-hole pairs, resulting in low photocatalytic activity. Element doping is known to be an efficient method to tune the unique electronic structure and band gap of g-C3N4, which considerably broaden the light responsive range and enhance the charge separation. This review summarizes the recent progress in the development of efficient and low cost doped g-C3N4 systems in various realms such as photocatalytic hydrogen evolution, reduction of carbon dioxide, photocatalytic removal of contaminants in wastewater and gas phase. Typically, metal doping, nonmetal doping, co-doping and heterojunction based on doped g-C3N4 have been explored to simultaneously tune the crystallographic, textural and electronic structures for improving photocatalytic activity by enhancing the light absorption, facilitating the charge separation and transportation and prolonging the charge carrier lifetime. Finally, the current challenges and the crucial issues of element doped g-C3N4 photocatalysts that need to be addressed in future research are presented. This review presented herein can pave a novel avenue and add invaluable knowledge to the family of element doped g-C3N4 for the develop of more effective visible-light-driven photocatalysts.
      Graphical abstract image

      PubDate: 2017-06-12T03:24:18Z
      DOI: 10.1016/j.apcatb.2017.06.003
      Issue No: Vol. 217 (2017)
       
  • Catalytic synthesis of polyoxymethylene dimethyl ethers (OME): A review
    • Authors: Christophe J. Baranowski; Ali M. Bahmanpour; Oliver Kröcher
      Pages: 407 - 420
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Christophe J. Baranowski, Ali M. Bahmanpour, Oliver Kröcher
      Polyoxymethylene dimethyl ethers (OME) containing 3–5 CH2O units (OME3–5) are appealing oxygenated fuels, which can be used in diesel engines with only slight fuel system modifications. Their combustion leads to reduced hazardous exhaust gas emissions compared to standard diesel. Due to the absence of C-to-C bonds, they considerably reduce soot formation, allowing in turn significantly higher exhaust gas recirculation (EGR) rates to reduce NOx emissions. Established liquid-phase OME production processes involve trioxane as a costly intermediate. Moreover, the OME product equilibrium composition follows a Schulz-Flory distribution making selective synthesis of specific chain length cumbersome. Current research efforts focus on simplifying the existing processes by using fewer steps, simpler reactants and less energy. Several catalyst classes were reported to catalyze OME acid synthesis. Little is known about the reaction mechanisms and the elementary steps involved. This review highlights the need for more systematic research on new reactants, efficient catalysts and simpler processes.
      Graphical abstract image

      PubDate: 2017-06-16T08:06:05Z
      DOI: 10.1016/j.apcatb.2017.06.007
      Issue No: Vol. 217 (2017)
       
  • Cu-exchanged Al-rich SSZ-13 zeolite from organotemplate-free synthesis as
           NH3-SCR catalyst: Effects of Na+ ions on the activity and hydrothermal
           stability
    • Authors: Zhenchao Zhao; Rui Yu; Rongrong Zhao; Chuan Shi; Hermann Gies; Feng-Shou Xiao; Dirk De Vos; Toshiyuki Yokoi; Xinhe Bao; Ute Kolb; Mathias Feyen; Robert McGuire; Stefan Maurer; Ahmad Moini; Ulrich Müller; Weiping Zhang
      Pages: 421 - 428
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Zhenchao Zhao, Rui Yu, Rongrong Zhao, Chuan Shi, Hermann Gies, Feng-Shou Xiao, Dirk De Vos, Toshiyuki Yokoi, Xinhe Bao, Ute Kolb, Mathias Feyen, Robert McGuire, Stefan Maurer, Ahmad Moini, Ulrich Müller, Weiping Zhang
      The relatively low activity at lower temperatures and high cost of SSZ-13 zeolite from organotemplate synthesis are two of major problems of presently commercialized Cu-SSZ-13 catalysts for NH3-SCR reaction. Cu-exchanged Al-rich SSZ-13 catalysts with Si/Al=4 from organotemplate-free synthesis have been prepared, and show superior NH3-SCR performance with NO conversions above 85% at wide-temperature window ranging from 150 to 650°C. Cu-Na-SSZ-13 catalysts with varied amount of residual Na+ were prepared by partial ion-exchange of as-prepared Al-rich Na-SSZ-13, and it’s found that Cu-Na-SSZ-13 catalyst with moderate Na+ content can improve both the low-temperature activity and its hydrothermal stability. 27Al and 1H MAS NMR spectra indicate that residual Na+ can stabilize the framework Al in Al-rich SSZ-13 zeolite. UV-Vis-NIR and H2-TPR spectra demonstrate that Na+ co-cations enhance the reducibility of Cu2+, whereas too much amount of Na+ may result in the formation of CuOx during the hydrothermal treatment, and further decrease the hydrothermal stability of Cu-Na-SSZ-13 catalyst. The optimized organotemplate-free Cu-Na-SSZ-13 with 2.7wt% Cu and 1.7wt% Na exhibits almost the same NO conversions as the commercial high-silica Cu-SSZ-13 catalyst at 150–550°C after 750 and 800°C hydrothermal aging, and shows promising practical applications.
      Graphical abstract image

      PubDate: 2017-06-16T08:06:05Z
      DOI: 10.1016/j.apcatb.2017.06.013
      Issue No: Vol. 217 (2017)
       
  • Controlling the amount of co-catalyst as a critical factor in determining
           the efficiency of photoelectrodes: The case of nickel (II) hydroxide on
           vanadate photoanodes
    • Authors: Javier Quiñonero; Roberto Gómez
      Pages: 437 - 447
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Javier Quiñonero, Roberto Gómez
      A commonly followed strategy to enhance the performance of photoelectrodes for achieving viable water splitting devices consists in the use of co-catalysts. However, fine control of the amount of co-catalyst deposited on the electrode surface usually does not receive much attention, although it is an essential factor that crucially determines the efficiency of photoelectrodes. In this context, this study illustrates how the dark electrochemical characterization of co-catalyst-modified photoanodes may provide valuable information on the precise amount of electroactive co-catalyst present on the surface, facilitating our understanding of the manner in which co-catalysts work and paving the way for their optimization. For this purpose, ultrathin Ni(OH)2 layers were deposited on either doped or pristine BiVO4 and FeVO4 photoanodes by a cost-effective and versatile chemical bath deposition method in which the deposition time allows to control the Ni(OH)2 loading. The deposited Ni(OH)2 is demonstrated to successfully catalyze the photoelectrochemical water oxidation process on both BiVO4 and FeVO4 electrodes, by improving the effective transfer of photogenerated holes from the semiconductor to solution. In fact, the electrocatalytic activity of the Ni(OH)2-modified photoanodes rapidly increases with the amount of deposited Ni(OH)2 until an optimum value is reached equivalent to only 0.46 and 1.68 Ni(OH)2 monolayers for BiVO4 and FeVO4 electrodes, respectively. Under these conditions, Ni(OH)2 enhances the photocurrent generation by a factor of 2 for BiVO4 and of 1.2 for FeVO4 photoanodes in contact with slightly alkaline solutions. The small loadings of Ni(OH)2 leading to an optimum photoanode behavior indicate that hole transfer is favored on vanadate active surface sites, which would also be the preferential sites for Ni(OH)2 deposition. Additional amounts of co-catalyst deposited for longer times induce a drastic decrease in the photoelectrocatalytic activity due to charge recombination at the semiconductor/Ni(OH)2 interface, probably enhanced by the low carrier mobility in Ni(OH)2. On the other hand, this study demonstrates that the preparation of efficient photoanodes for oxygen evolution with an extremely small amount of co-catalyst through a facile and scalable method is possible.
      Graphical abstract image

      PubDate: 2017-06-16T08:06:05Z
      DOI: 10.1016/j.apcatb.2017.06.005
      Issue No: Vol. 217 (2017)
       
  • Enhanced visible light photocatalytic water reduction from a
           g-C3N4/SrTa2O6 heterojunction
    • Authors: Shiba P. Adhikari; Zachary D. Hood; Hui Wang; Rui Peng; Alex Krall; Hui Li; Vincent W. Chen; Karren L. More; Zili Wu; Scott Geyer; Abdou Lachgar
      Pages: 448 - 458
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Shiba P. Adhikari, Zachary D. Hood, Hui Wang, Rui Peng, Alex Krall, Hui Li, Vincent W. Chen, Karren L. More, Zili Wu, Scott Geyer, Abdou Lachgar
      A new g-C3N4/SrTa2O6 heterojunction photocatalyst was designed and prepared by chimie douce (soft chemistry) method where carbon nitride (g-C3N4) was deposited over the metastable perovskite phase of SrTa2O6. The morphological study of the heterojunction using SEM and STEM revealed that g-C3N4 nanofibers are dispersed uniformly on the surface of SrTa2O6 plates leading to the intimate contact between them. The heterojunction could achieve a high and stable visible light photocatalytic H2 generation of 137mmol/h/mole of g-C3N4, which is much larger than the amount of hydrogen generated by one mole of pristine g-C3N4. A plausible mechanism for the observed enhanced photocatalytic activity for the heterojunction is proposed on the basis of effective charge separation of photogenerated electron-hole pairs, supported by band position calculations and photo-physical properties of g-C3N4 and SrTa2O6.
      Graphical abstract image

      PubDate: 2017-06-16T08:06:05Z
      DOI: 10.1016/j.apcatb.2017.05.092
      Issue No: Vol. 217 (2017)
       
  • 3D Co-N-doped hollow carbon spheres as excellent bifunctional
           electrocatalysts for oxygen reduction reaction and oxygen evolution
           reaction
    • Authors: Shichang Cai; Zihan Meng; Haolin Tang; Yi Wang; Panagiotis Tsiakaras
      Pages: 477 - 484
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Shichang Cai, Zihan Meng, Haolin Tang, Yi Wang, Panagiotis Tsiakaras
      Non-precious materials have been considered as promising bifunctional catalysts towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). In the present work, a three dimensional (3D) Co-N co-doped hollow carbon sphere (HCS) electrocatalyst is synthesized at room temperature by the aid of a facile preparation method. The as obtained Co-N co-doped catalyst exhibits excellent catalytic activity towards both ORR and OER due to its high surface area and to 3D hollow architecture. For the ORR, the catalyst shows more positive onset-potential (of ∼0.962V vs. RHE) and larger diffusion limiting current density (5.55mAcm−2) compared with benchmark Pt/C catalyst in alkaline medium. Moreover, the as synthesized catalyst exhibits low potential (1.720V vs. RHE) at the current density of 10mAcm−2 and small Tafel slope (81mVdec−1) for OER. In addition, the catalyst exhibits remarkable methanol tolerance and good long-term stability under working conditions. This strategy provides a facile and effective method for the preparation of non-noble metal catalysts with 3D hollow structure for energy conversion and storage applications.
      Graphical abstract image

      PubDate: 2017-06-16T08:06:05Z
      DOI: 10.1016/j.apcatb.2017.06.008
      Issue No: Vol. 217 (2017)
       
  • Cu2O/TiO2 heterostructures for CO2 reduction through a direct Z-scheme:
           Protecting Cu2O from photocorrosion
    • Authors: Matías E. Aguirre; Ruixin Zhou; Alexis J. Eugene; Marcelo I. Guzman; María A. Grela
      Pages: 485 - 493
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Matías E. Aguirre, Ruixin Zhou, Alexis J. Eugene, Marcelo I. Guzman, María A. Grela
      The development of artificial photosynthesis aims to solve the increasing energy demand and associated environmental problems. A model photosynthetic system employing a composite of semiconductors with a Z-scheme can potentially mimic the combined power of photosystems 1 and 2 to transfer electrons. In this work, octahedral cuprous oxide covered with titanium dioxide nanoparticles (Cu2O/TiO2) are synthesized by a solvothermal strategy that provides high morphological and crystallographic control. The formation of a p-n heterojunction and characterization of the Type II band alignment of the composite are performed by diffuse reflectance UV-visible (DRUV) spectroscopy, ultraviolet photoelectron spectroscopy (UPS), and X-ray photoelectron spectroscopy (XPS). Upon UV-visible irradiation (λ≥305nm) of the composite in the presence of water vapor as the hole scavenger, the photoreduction of CO2(g) proceeds selectively to generate CO(g). The production rate of CO by the composite, R CO =2.11μmolgcat −1 h−1, is 4-times larger than for pure Cu2O under identical conditions. Contrasting XPS analyses of Cu2O and Cu2O/TiO2, during photocatalysts operation and the detection of photogenerated hydroxyl radicals (HO) in the heterostructure at variance with the results obtained for pure Cu2O are taken as evidences that TiO2 protects Cu2O from undergoing photocorrosion. These results provide direct evidence of an efficient Z-scheme as the main mechanism for harvesting energy during CO2 reduction in the synthesized materials.
      Graphical abstract image

      PubDate: 2017-06-16T08:06:05Z
      DOI: 10.1016/j.apcatb.2017.05.058
      Issue No: Vol. 217 (2017)
       
  • Recent progress for direct synthesis of dimethyl ether from syngas on the
           heterogeneous bifunctional hybrid catalysts
    • Authors: K. Saravanan; Hyungwon Ham; Noritatsu Tsubaki; Jong Wook Bae
      Pages: 494 - 522
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): K. Saravanan, Hyungwon Ham, Noritatsu Tsubaki, Jong Wook Bae
      The recent rising demand of renewable energies and climate changes has been driving intensive academic researches into new chemical routes to sustainable and clean fuel productions in order to meet the demands of industrial evolution by solving energy crisis due to limited fossil fuel reservoirs and increasing environmental pollutants. Dimethyl ether (DME) is a multi-purpose synthetic fuel and chemical that can be used as an excellent alternative to diesel fuel and liquefied petroleum gas (LPG). The present review paper briefly provides an overview of the recent developments for a direct synthesis of DME from synthesis gas (syngas, CO+H2) over some hybridized bifunctional heterogeneous catalysts composed of copper-based hydrogenation catalysts with solid acid components such as alumina or zeolites mainly, where the catalytic activities significantly depend on its properties influenced by synthesis protocols, porosities, surface areas, interactions of active metals with supports, distributions of metal particles on the supports and so on. We have also briefly covered the hydrogenation of CO2, a model reaction for the utilization of CO2 containing in syngas, to produce DME and thereby significantly mitigate its environmental impacts. Furthermore, the catalytic performances of the direct synthesis of DME by hydrogenation of carbon oxides were explained in terms of the acid sites of the solid acid catalysts and surface area of metallic copper nanoparticles in the hybridized bifunctional catalysts with their preparation protocols.
      Graphical abstract image

      PubDate: 2017-06-16T08:06:05Z
      DOI: 10.1016/j.apcatb.2017.05.085
      Issue No: Vol. 217 (2017)
       
  • Control the energy band potential of ZnMgO solid solution with enhanced
           photocatalytic hydrogen evolution capacity
    • Authors: Hongwei Wang; Wenqiang Zheng; Weibing Li; FengHui Tian; Shaoping Kuang; Yuyu Bu; Jin-Ping Ao
      Pages: 523 - 529
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Hongwei Wang, Wenqiang Zheng, Weibing Li, FengHui Tian, Shaoping Kuang, Yuyu Bu, Jin-Ping Ao
      In this study, we prepared a novel hierarchic nanorod ZnMgO solid solution photocatalyst, and in the crystal, part of Zn atoms were replaced by Mg atoms. Experimental results and theoretical calculation data firstly indicated that the energy band structure of the ZnO can be tuned with the Mg elements doping in it. Especially, during this process, the conduction band (CB) potential of ZnMgO solid solution moved to more negative site gradually with the Mg content increasing, which is an important characteristic for n-type water splitting photocatalyst. When the mole ratio of Mg in the reaction solution reach to 50%, corresponding end-product ZnMgO showed a much more negative CB potential (−0.46V vs NHE) than pure ZnO (−0.05V vs NHE), and the photocatalytic for hydrogen evolution product of ZnMgO solid solution increased dramatically than pure ZnO (from near zero of ZnO to 1103.9μmol/g in 4h). Furthermore, in the future, based on the ZnMgO solid solution prepared in this study, more visible-light-responsive solid solution with suitable water splitting band structure, such as ZnMgON and ZnMgOS etc., can be expected.
      Graphical abstract image

      PubDate: 2017-06-16T08:06:05Z
      DOI: 10.1016/j.apcatb.2017.04.079
      Issue No: Vol. 217 (2017)
       
  • In-situ synthesis of CoP co-catalyst decorated Zn0.5Cd0.5S photocatalysts
           with enhanced photocatalytic hydrogen production activity under visible
           light irradiation
    • Authors: Dongsheng Dai; Hao Lei Changcun Han Yangqin Gao Songsong Yan
      Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): Dongsheng Dai, Hao Xu, Lei Ge, Changcun Han, Yangqin Gao, Songsong Li, Yan Lu
      The generation of hydrogen (H2) through photocatalytic water splitting with the employment of various co-catalysts has attracted much attention. In this study, the CoP was successfully decorated on Zn0.5Cd0.5S as a highly efficient co-catalyst via a two-step in-situ chemical deposition method. The chemical as well as photophysical properties of the as-obtained CoP/Zn0.5Cd0.5S samples were characterized by X-ray diffractometry (XRD), Transmission electron microscope (TEM), UV–vis diffusion reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and surface photovoltage spectroscopy (SPV). The CoP/Zn0.5Cd0.5S composite sample with 5% molar content showed the highest photocatalytic H2 evolution activity with a corresponding H2 evolution rate of 734umolh−1, which was about 20 times higher than that of pure Zn0.5Cd0.5S sample and 2 times higher than Pt loaded Zn0.5Cd0.5S sample under visible light irradiation. The photocatalytic activity of the CoP/Zn0.5Cd0.5S composite sample was stable even after 4 cycling photocatalytic experiments. A possible mechanism on the photocatalytic enhancement of CoP was systematically investigated, which can provide a novel concept for the synthesis of other desirable photocatalytic materials with high photocatalytic performance.
      Graphical abstract image

      PubDate: 2017-06-16T08:06:05Z
       
  • Unexpected stability of CuO/Cryptomelane catalyst under Preferential
           Oxidation of CO reaction conditions in the presence of CO2 and H2O
    • Abstract: Publication date: 15 November 2017
      Source:Applied Catalysis B: Environmental, Volume 217
      Author(s): A. Davó-Quiñonero, D. Lozano-Castelló, A. Bueno-López
      The catalytic activity of CuO/Cryptomelane for the preferential oxidation of CO in H2-rich streams has been studied in the absence and presence of H2O and CO2, paying special attention to the catalyst stability and to changes on its physical-chemical properties under CO-PROX reaction conditions. For fresh CuO/cryptomelane catalyst, the presence of CO2 and/or H2O in the CO-PROX feed partially inhibits CO oxidation due to chemisorption of H2O and CO2 on the catalyst. H2O chemisorption on CuO/Cryptomelane is stronger than CO2 chemisorption, and simultaneous CO2 and H2O adsorption has a synergetic effect that enhances co-adsorption and significantly hinders CO oxidation. On the contrary, the presence of CO2 +H2O in the CO-PROX reaction mixture has a positive effect in the CuO/Cryptomelane stability upon several consecutive reaction cycles in the 25–200°C range. XRD showed that chemisorbed CO2 +H2O species partially prevent the catalyst deactivation due to cryptomelane reduction to hausmannite (Mn3O4) under the strongly reductive environment of the CO-PROX reaction, and H2-TPR and Raman spectroscopy characterisation support that the cryptomelane structure is less damaged under CO-PROX conditions in the presence of CO2 and H2O than in the absence of these species. Therefore, interestingly under CO2 +H2O environment (realistic CO-PROX conditions) CuO/Cryptomelane catalyst performs an improved catalytic activity.
      Graphical abstract image

      PubDate: 2017-06-16T08:06:05Z
       
 
 
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