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  Subjects -> ENGINEERING (Total: 2417 journals)
    - CHEMICAL ENGINEERING (207 journals)
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    - ELECTRICAL ENGINEERING (111 journals)
    - ENGINEERING (1267 journals)
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ENGINEERING (1267 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 8)
3D Research     Hybrid Journal   (Followers: 21)
AAPG Bulletin     Hybrid Journal   (Followers: 8)
AASRI Procedia     Open Access   (Followers: 14)
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: 273)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 3)
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: 7)
Advanced Journal of Graduate Research     Open Access  
Advanced Science     Open Access   (Followers: 5)
Advanced Science Focus     Free   (Followers: 5)
Advanced Science Letters     Full-text available via subscription   (Followers: 10)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 7)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 18)
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: 27)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 13)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 21)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 29)
Advances in Operations Research     Open Access   (Followers: 12)
Advances in OptoElectronics     Open Access   (Followers: 6)
Advances in Physics Theories and Applications     Open Access   (Followers: 13)
Advances in Polymer Science     Hybrid Journal   (Followers: 43)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Remote Sensing     Open Access   (Followers: 44)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aerobiologia     Hybrid Journal   (Followers: 3)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 6)
AIChE Journal     Hybrid Journal   (Followers: 35)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access   (Followers: 1)
Alexandria Engineering Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 26)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 10)
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: 24)
Analele Universitatii Ovidius Constanta - Seria Chimie     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 4)
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)
Antarctic Science     Hybrid Journal   (Followers: 1)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 18)
Applied Clay Science     Hybrid Journal   (Followers: 6)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 11)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 4)
Applied Nanoscience     Open Access   (Followers: 8)
Applied Network Science     Open Access   (Followers: 3)
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 5)
Applied Sciences     Open Access   (Followers: 3)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 5)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 8)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
Asia-Pacific Journal of Science and Technology     Open Access  
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 1)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 8)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Current Engineering & Maths     Open Access  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 9)
Avances en Ciencias e Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 5)
Batteries     Open Access   (Followers: 6)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 28)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 1)
BER : Motor Trade Survey     Full-text available via subscription  
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 1)
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)
Beyond : Undergraduate Research Journal     Open Access  
Bhakti Persada : Jurnal Aplikasi IPTEKS     Open Access  
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Bilge International Journal of Science and Technology Research     Open Access  
Biofuels Engineering     Open Access   (Followers: 1)
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 11)
Biomedical Engineering     Hybrid Journal   (Followers: 15)
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: 21)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 37)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 9)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal   (Followers: 1)
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 2)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Bitlis Eren University Journal of Science and Technology     Open Access  
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription   (Followers: 1)
Boundary Value Problems     Open Access   (Followers: 1)
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 13)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 14)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers, Droit, Sciences et Technologies     Open Access  
Calphad     Hybrid Journal   (Followers: 2)
Canadian Geotechnical Journal     Hybrid Journal   (Followers: 31)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 42)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 6)
Case Studies in Thermal Engineering     Open Access   (Followers: 5)
Catalysis Communications     Hybrid Journal   (Followers: 6)
Catalysis Letters     Hybrid Journal   (Followers: 2)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 7)
Catalysis Science and Technology     Free   (Followers: 8)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 7)
CEAS Space Journal     Hybrid Journal   (Followers: 2)
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 3)
Central European Journal of Engineering     Hybrid Journal  
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: 3)
CienciaUAT     Open Access   (Followers: 1)
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: 13)
City, Culture and Society     Hybrid Journal   (Followers: 21)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Clean Air Journal     Full-text available via subscription   (Followers: 1)
Clinical Science     Full-text available via subscription   (Followers: 9)
Coal Science and Technology     Full-text available via subscription   (Followers: 3)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 6)
Coatings     Open Access   (Followers: 4)
Cogent Engineering     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Color Research & Application     Hybrid Journal   (Followers: 2)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 14)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 14)
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: 28)
Composite Interfaces     Hybrid Journal   (Followers: 7)
Composite Structures     Hybrid Journal   (Followers: 278)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 209)
Composites Part B : Engineering     Hybrid Journal   (Followers: 250)
Composites Science and Technology     Hybrid Journal   (Followers: 193)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access   (Followers: 1)
Computational Geosciences     Hybrid Journal   (Followers: 16)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 8)
Computer Science and Engineering     Open Access   (Followers: 19)
Computers & Geosciences     Hybrid Journal   (Followers: 31)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 8)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 5)
Computers and Geotechnics     Hybrid Journal   (Followers: 11)
Computing and Visualization in Science     Hybrid Journal   (Followers: 7)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 33)
Conciencia Tecnologica     Open Access  
Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 8)

        1 2 3 4 5 6 7 | Last

Journal Cover
Applied Catalysis B: Environmental
Journal Prestige (SJR): 3.152
Citation Impact (citeScore): 11
Number of Followers: 18  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0926-3373
Published by Elsevier Homepage  [3163 journals]
  • Incorporation of CoO nanoparticles in 3D marigold flower-like hierarchical
           architecture MnCo2O4 for highly boosting solar light photo-oxidation and
           reduction ability
    • Authors: Jianhua Zheng; Zhang Lei
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Jianhua Zheng, Zhang Lei
      Most previous reported photocatalysts designs show that, either photocatalytic oxidation (PCO) or reduction (PCR) is inhibited due to the insufficient govern of the photo-excited h + and e−. To overcome this problem, we consider that both PCO and PCR could be improved simultaneously by employing suitable photocatalyst. Herein, the novel 3D marigold flower-like hierarchical architecture CoO@MnCo2O4 was successfully synthesized by anchoring CoO nanoparticles (NPs) on MnCo2O4 flower using a facile solvothermal method followed thermal annealing treatment under N2 atmosphere for the first time. This strategy relies on the formation of a p-n heterostructure with matching energy band gaps, in which CoO NPs tightly adhere to the surface of hierarchical MnCo2O4 microflowers, and the flower-like MnCo2O4 act as scaffold to disperse CoO NPs. The as-fabricated CoO@MnCo2O4 hybrid not only presented remarkable performance for PCO of tetracycline (TC) but also exhibited excellent PCR of hexavalent chromium (Cr (VI)) under visible light irradiation. Meanwhile, the photocatalyst also can be used for treatment a mixture of them and exhibited promoted photocatalytic efficiency. That's the primary reason that h+ and e- can play their own roles to accomplish PCO and PCR, respectively. Moreover, the unique 3D hierarchical microflowers structure not only provide a higher specific surface area, sufficient active sites and enhanced light harvesting, but also significantly decrease the aggregation of CoO particles. The appearance photocatalytic mechanism of the p-n heterostructure system was also discussed in detail. The facile synthesis strategy and outstanding photocatalytic performance make the 3D hierarchical architecture CoO@MnCo2O4 a promising candidate as a visible light photocatalyst.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.060
      Issue No: Vol. 237 (2018)
       
  • Conformal coating of ultrathin metal-organic framework on semiconductor
           electrode for boosted photoelectrochemical water oxidation
    • Authors: Yu-Jie Dong; Jin-Feng Liao; Zi-Cheng Kong; Yang-Fan Xu; Ze-Jie Chen; Hong-Yan Chen; Dai-Bin Kuang; Dieter Fenske; Cheng-Yong Su
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Yu-Jie Dong, Jin-Feng Liao, Zi-Cheng Kong, Yang-Fan Xu, Ze-Jie Chen, Hong-Yan Chen, Dai-Bin Kuang, Dieter Fenske, Cheng-Yong Su
      Exploring efficient photocatalysts for water oxidation is highly demanded because of their significant role in artificial photosynthesis. The research of metal-organic frameworks (MOFs) based photoelectrochemical (PEC) water splitting is promising but still in its infancy due to the challenge to fabricate high-quality MOFs photoelectrode. Here an Fe2O3/Fe-based MOF core/shell nanorod is prepared for efficient PEC water oxidation via a facile surfactant-assisted solvothermal method. With polyvinylpyrrolidone (PVP) molecules as intermedia, an ultrathin MOF shell of several nanometers thick can be controllably grown on the surface of Fe2O3 nanorod. Charge dynamical behaviors study by ultrafast transient absorption spectroscopy (TAS) and photoelectrochemical impedance spectroscopy (PEIS), reveal that the ultrathin MOF shell is crucial to promote the charge separation by providing a cascade band level, but also accelerate the hole injection efficiency via exposing more accessible Fe-oxo cluster active sites. Accompanied with good visible-light response, the Ti-doped Fe2O3/NH2-MIL-101(Fe) photoanode delivers a boosted photocurrent density of 2.27 mA cm−2 at 1.23 V vs. RHE, which is about 2.3 folds of that of pristine Fe2O3. This study provides new insights into the rational design of semiconductor/MOFs hybrid materials for photo/photoelectrochemical catalysis.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.059
      Issue No: Vol. 237 (2018)
       
  • Synchronized biphotonic process triggering CC coupling catalytic reactions
    • Authors: Carmen G. López-Calixto; Marta Liras; Victor A. de la Peña O’Shea; Raúl Pérez-Ruiz
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Carmen G. López-Calixto, Marta Liras, Victor A. de la Peña O’Shea, Raúl Pérez-Ruiz
      Activation of aryl(Ar)-halides for CC coupling catalytic reactions using visible light has become one of the most challenging tasks in organic synthesis since it offers effective and safer alternatives to traditional dehalogenation protocols. The insufficient energy provided by visible light to cleave such strong CH alogen bonds certainly makes necessary the development of new protocols to overcome this limitation. We report here the application of photon upconversion (UC) technology based on triplet-triplet annihilation (TTA) to a CC coupling catalytic reaction, a possibility that has not been investigated to date. This synchronized biphotonic process (TTA-UC) activates successfully Ar-halides with visible light. Based on product analysis and spectroscopic experiments, a cascade process combining photophysical and photochemical steps is proposed for the mechanism rationalization. Visible light, ambient temperature and pressure, low-loading metal-free photocatalysts and no additives make this protocol very attractive for applications to the synthesis of fine chemical building blocks, pharmaceuticals, agrochemicals or new materials.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.062
      Issue No: Vol. 237 (2018)
       
  • Exceptional visible-light activities of g-C3N4 nanosheets dependent on the
           unexpected synergistic effects of prolonging charge lifetime and
           catalyzing H2 evolution with H2O
    • Authors: Xuliang Zhang; Xinxin Zhang; Jiadong Li; Jianhui Sun; Ji Bian; Jinshuang Wang; Yang Qu; Rui Yan; Chuanli Qin; Liqiang Jing
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Xuliang Zhang, Xinxin Zhang, Jiadong Li, Jianhui Sun, Ji Bian, Jinshuang Wang, Yang Qu, Rui Yan, Chuanli Qin, Liqiang Jing
      It is highly desired to develop an efficient g-C3N4-based photocatalyst for energy production under visible-light irradiation. Herein, it is shown that the optimized g-C3N4 nanosheet-based photocatalyst could exhibit exceptional photocatalytic activities for H2 evolution under visible-light irradiation, by ∼14-time improvement compared to that of bare g-C3N4 one. It is confirmed by the methods of transient-state surface photovoltage responses, transient-state PL spectra and electrochemical measurements that the exceptional photocatalytic activities are attributed to the unexpected synergistic effects of prolonging the charge lifetime and catalyzing H2 evolution by coupling nanocrystalline anatase TiO2 as a proper-energy platform to accept visible-light-excited electrons from g-C3N4 and by decorating a nano-sized noble metal as the co-catalyst respectively. Among three decorated noble metals (Ag, Au and Pt), to prolong the photogenerated charge lifetime is much meaningful for the used noble metal cocatalyst with weak catalytic function like Ag in H2 evolution. Using nanocrystalline SnO2 to replace TiO2 is also applicable for the synergistic effect. Moreover, it is clarified by the designed experiment on photocatalytic CO2 conversion to CD4 in the presence of methanol in D2O that the resource of evolved H2 is mainly from the adsorbed H2O other than the disassociated H+ from methanol.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.034
      Issue No: Vol. 237 (2018)
       
  • An active and robust Si-Fe/N/C catalyst derived from waste reed for oxygen
           reduction
    • Authors: Qiliang Wei; Xiaohua Yang; Gaixia Zhang; Dongniu Wang; Lucia Zuin; Dustin Banham; Lijun Yang; Siyu Ye; Youling Wang; Mohamed Mohamedi; Shuhui Sun
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Qiliang Wei, Xiaohua Yang, Gaixia Zhang, Dongniu Wang, Lucia Zuin, Dustin Banham, Lijun Yang, Siyu Ye, Youling Wang, Mohamed Mohamedi, Shuhui Sun
      The conversion of biomass waste into valuable carbon composites as efficient non-precious metal oxygen-reduction electrocatalysts is attractive for the development of commercially viable fuel-cell and metal-air battery technologies. Herein, a highly active and robust Si-contained Fe/N/C catalyst is prepared based on the porous carbon deriving from waste reed stalk after carbonization and KOH corrosion. Reed waste is a natural, abundantly available, and yearly renewable source, acting as the single precursor for Si containing-carbon substrate. The typical product (Si-Fe20/N/C1_6 in this work) possesses a high BET specific surface area, porous structure with high pyridinic-N and pyrrolic-N content. The X-ray absorption near edge structure (XANES), Raman, X-ray photoelectron spectroscopy (XPS) measurements and electrochemical measurements show that Si facilitates incorporation of more N to coordinate with Fe in the porous carbon and induces more graphitic carbon in the catalyst. The sample Si-Fe20/N/C1_6 exhibits better activity and superior stability than the Fe20/N/C counterpart and commercial Pt/C catalyst for the oxygen reduction reaction (ORR) in 0.1 M KOH electrolyte. The results suggest a promising route based on economical and sustainable biomass towards the development and engineering of value-added carbon materials as robust catalysts for oxygen reduction.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.046
      Issue No: Vol. 237 (2018)
       
  • Effects of dealumination on the performance of Ni-containing BEA catalysts
           in bioethanol steam reforming
    • Authors: Wojciech Gac; Magdalena Greluk; Grzegorz Słowik; Yannick Millot; Laetitia Valentin; Stanislaw Dzwigaj
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Wojciech Gac, Magdalena Greluk, Grzegorz Słowik, Yannick Millot, Laetitia Valentin, Stanislaw Dzwigaj
      The effects of dealumination of BEA zeolite on the formation of nickel active sites and the performance of Ni-containing BEA zeolite catalysts in the steam reforming of ethanol have been studied. Ni-containing BEA zeolite catalysts were prepared by the impregnation of unmodified and dealuminated BEA zeolites with Ni(NO3)2 precursor. The properties of Ni10HAlBEA and Ni10SiBEA zeolite catalysts were studied by means of X-ray diffraction, 1H, 27Al and 29Si magic-angle spinning nuclear magnetic resonance, Fourier-transform infrared and Raman spectroscopy, transmission electron microscopy, temperature-programmed reduction, temperature-programmed ammonia and hydrogen desorption methods. High initial activity and selectivity of Ni10HAlBEA to hydrogen and carbon dioxide with unmodified BEA zeolite support in the steam reforming of ethanol reaction performed at 500 °C was observed. However, fast deactivation of Ni10HAlBEA catalyst, manifested in the decrease of water conversion, drop of selectivity to H2 and CO2, and increase in the selectivity to ethylene with the time-on-stream, was observed. In contrast, Ni10SiBEA zeolite catalyst showed lower initial activity but higher durability and resistance for carbon deposition. It was stated that dealumination of BEA zeolite led to the slight structural changes and simultaneously pronounced decrease of acidity. Formation of the large nickel crystallites was hindered on Ni10SiBEA zeolite catalyst. TEM and Raman spectroscopy studies indicated that deactivation of Ni10HAlBEA was related to formation of nickel mediated filamentous, graphitic and amorphous carbon deposits. Much smaller amounts of filamentous carbons were observed on the Ni10SiBEA zeolite catalyst prepared by the use of dealuminated zeolite support.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.040
      Issue No: Vol. 237 (2018)
       
  • Regeneration of a sulfur-poisoned methane combustion catalyst: Structural
           evidence of Pd4S formation
    • Authors: Ville H. Nissinen; Niko M. Kinnunen; Mika Suvanto
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Ville H. Nissinen, Niko M. Kinnunen, Mika Suvanto
      Decomposition of PdSO4, a species responsible for the deactivation of Pd-based methane combustion catalysts, was studied using a PdSO4/Al2O3 model system. PdSO4 was observed to behave differently under different reaction conditions. The decomposition of PdSO4 under inert atmosphere probably involved only one reaction step and resulted in the formation of metallic palladium. Under H2-containing atmosphere, the decomposition of PdSO4 resulted eventually in the formation of Pd4S, which is probably one of the many possible sulfur-containing palladium species that can be formed during regeneration of a sulfur-poisoned Pd-rich methane combustion catalyst. The formation of Pd4S can provide a reasonable explanation to the threshold temperature of sulfur removal from the catalyst, as well as to the residual sulfur present in the catalyst after regeneration under reductive atmosphere. Overall, the results obtained in the study provide deeper insight into the regeneration process of Pd-based catalysts, possibly enabling development of a more efficient regeneration strategy.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.057
      Issue No: Vol. 237 (2018)
       
  • A rapidly room-temperature-synthesized Cd/ZnS:Cu nanocrystal photocatalyst
           for highly efficient solar-light-powered CO2 reduction
    • Authors: Xianguang Meng; Guifu Zuo; Peixiao Zong; Hong Pang; Jian Ren; Xiongfeng Zeng; Shanshan Liu; Yi Shen; Wei Zhou; Jinhua Ye
      Pages: 68 - 73
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Xianguang Meng, Guifu Zuo, Peixiao Zong, Hong Pang, Jian Ren, Xiongfeng Zeng, Shanshan Liu, Yi Shen, Wei Zhou, Jinhua Ye
      An ideal photocatalyst that can promisingly convert CO2 should have suitable band gap and fully consider the activation of reaction. However, well-designed photocatalytic materials with these aspects are very limited. This study reports a highly efficient CO2 reduction photocatalyst based on ZnS nanocrystals which can be rapidly synthesized at room temperature and operated under solar light irradiation at all-inorganic reaction system. Two functional elements, Cu and Cd, are respectively used as dopant and cocatalyst of ZnS nanocrystal for selective CO2 reduction. Cu+ doping expands the photoabsorption of ZnS into visible light region and the simultaneous Cd2+ surface modification significantly improves the activity of CO2 reduction with 99% formic acid selectivity. A combination of charge density distribution and electronic state studies reveal that the Cd s orbital displays obviously higher density of states near band-edge with a relatively lower lying band center than that of Zn s orbital. This will greatly favor the charge transfer from conduction band of ZnS to the surface state created by Cd2+ for catalyzing CO2 reduction.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.066
      Issue No: Vol. 237 (2018)
       
  • Facet effect of Co3O4 nanocrystals on visible-light driven water oxidation
    • Authors: Xichen Zhou; Zhen Liu; Yifan Wang; Yong Ding
      Pages: 74 - 84
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Xichen Zhou, Zhen Liu, Yifan Wang, Yong Ding
      The deep comprehension of water oxidation mechanisms and structure-activity relationships on heterogeneous catalysts remains challenging. Here, facet effect of model spinel Co3O4 on water oxidation driven by visible-light is investigated in a well-established [Ru(bpy)3]2+-S2O8 2− (bpy = 2,2-bipyridine) biomimetic system to unveil the internal water oxidation mechanism for the first time. Spinel Co3O4 catalysts in the morphologies of nanocube, nanorod and nanosheet are synthesized successfully by bottom-up nanotechnologies, and they predominantly expose the well-defined crystal planes of {100}, {110} and {112}, respectively. Using time-resolved laser flash photolysis approach, the dynamically electronic transfer in photocatalytic courses of three Co3O4 catalysts are distinguished in the nanosecond scale. The three model catalysts show a facet-dependent activity rule that the water oxidation performance of {112} is similar with that of {110} and much better than that of {100}. The Co2+-Co2+ active sites with an ionic distance of 3.495 Å for catalyzing water oxidation only appear in {112} and {110} planes except for {100}, which is possibly responsible for the unique activity order of three Co3O4 catalysts. Furthermore, the Co2+ ions in the tetrahedral sites of spinel Co3O4 are confirmed to be more active than the Co3+ ions in the octahedral sites under visible-light driven water oxidation. The new insights shed a light on developing advanced nanocatalysts for oxygen evolution reaction.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.067
      Issue No: Vol. 237 (2018)
       
  • The influence of phosphorus on the catalytic properties, durability,
           sulfur resistance and kinetics of Cu-SSZ-13 for NOx reduction by NH3-SCR
    • Authors: Zhen Chen; Chi Fan; Lei Pang; Shujun Ming; Peng Liu; Tao Li
      Pages: 116 - 127
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Zhen Chen, Chi Fan, Lei Pang, Shujun Ming, Peng Liu, Tao Li
      The influence of phosphorus on the catalytic properties, durability, sulfur resistance and kinetics of Cu-SSZ-13 for NOx reduction by ammonia selective catalytic reduction (NH3-SCR) were systematically investigated to obtain a deeper understanding of the deactivation of Cu-SSZ-13 in the presence of phosphorus-containing impurities in diesel exhaust. An enhanced effect on NO conversion at low phosphorus loading was found above 450 ℃, probably due to the reduction of copper oxides that promote NH3 oxidation at high temperatures. As the phosphorus loading reached 0.4 mmol/gcatal, the framework dealumination and decrease of the BET specific surface area, acidity, and isolated Cu2+ ions accounted for the decrease in activity and hydrothermal stability over the entire temperature range. Simultaneously, the activity of phosphorus-impregnated samples tested in the presence of SO2 indicates that phosphorus accelerates the deactivation of Cu-SSZ-13 in the presence of SO2 at low temperatures, primarily due to the severe decrease of the Cu2+ ion content and partial coverage of the acid sites and active sites by phosphate and sulfate species. Additionally, kinetic analysis further demonstrated that phosphorus has an inhibitory effect on the SCR reaction rates at low temperatures and high phosphorus addition changes the NH3-SCR reaction kinetic parameters. The data presented herein provide a comprehensive picture of the interaction between phosphorus and Cu-SSZ-13.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.075
      Issue No: Vol. 237 (2018)
       
  • Effective shell wall thickness of vertically aligned ZnO-ZnS core-shell
           nanorod arrays on visible photocatalytic and photo sensing properties
    • Authors: Kugalur Shanmugam Ranjith; Rutely Burgos Castillo; Mika Sillanpaa; Ramasamy Thangavelu Rajendra Kumar
      Pages: 128 - 139
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Kugalur Shanmugam Ranjith, Rutely Burgos Castillo, Mika Sillanpaa, Ramasamy Thangavelu Rajendra Kumar
      Development of hierarchical core-shell semiconductor heterostructures ensue significant advancement in catalytic functional structures with improvised optical functionalities. Shell wall controlled vertically aligned ZnO-ZnS core-shell nanorod (NR) heterostructures were grown on transparent conductive substrates along the c-axis by sulfidation of aligned ZnO nanorod arrays for visible photocatalytic properties. The effects of the sulfidation time on the morphology, crystalline properties, optical property, photocurrent response, and photocatalytic activity of the catalyst arrays were studied under UV and visible light irradiation. The shell wall thickness of these heterostructures influenced in great extent the effective photo responsive charge separation and improved carrier mobility. ZnO-ZnS core-shell heterostructure having the shell wall thickness of 20 nm has exhibited more efficient visible photocatalytic behavior due to effective separation of carriers and improved visible absorption. On further increasing the wall thickness the catalytic efficiency was reduced due to the poor carrier (hole) mobility in the polycrystalline shell grains which induced the higher recombination rate. Stability and reusability of ZnO-ZnS core-shell nanostructures reveals that the ZnS acted as a protective layer over the ZnO NR arrays. In appraisal with ZnO NR arrays, the control over the shell wall thickness of ZnO-ZnS core-shell NR array attributed to the excellent visible photocatalytic activity and improvised absorption of light in visible region at ZnO-ZnS interface and effective separation of photogenerated electron-hole pairs at ZnO-ZnS heterojunctions.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.03.099
      Issue No: Vol. 237 (2018)
       
  • Graphitic carbon nitride-carbon nanofiber as oxygen catalyst in
           anion-exchange membrane water electrolyzer and rechargeable metal–air
           cells
    • Authors: Ji Eun Park; Mi-Ju Kim; Myung Su Lim; Sun Young Kang; Jong Kwan Kim; Seung-Hyeon Oh; Min Her; Yong-Hun Cho; Yung-Eun Sung
      Pages: 140 - 148
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Ji Eun Park, Mi-Ju Kim, Myung Su Lim, Sun Young Kang, Jong Kwan Kim, Seung-Hyeon Oh, Min Her, Yong-Hun Cho, Yung-Eun Sung
      Graphitic carbon nitride-carbon nanofiber (g-CN-CNF) was synthesized as a bifunctional catalyst in an anion-exchange membrane water electrolyzer (AEMWE), and primary and rechargeable Zn–air cells. The g-CN-CNF catalyst shows high catalytic activity for oxygen reduction reaction and oxygen evolution reaction in half-cell, with low overpotentials and low Tafel slopes. The high activity is attributed to the synergistic effect of abundant active sites and the electrical conductivity following the pyrolysis of g-CN and CNF. As a result, AEMWE with the g-CN-CNF anode, the first application of a carbon-based catalyst, exhibits outstanding performance that is the highest record in the literature for AEMWE using a non-noble metal catalyst. In addition, the performance and durability of Zn-air cells with g-CN-CNF cathode outperform those fabricated with commercial platinum.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.073
      Issue No: Vol. 237 (2018)
       
  • Acrolein production from methanol and ethanol mixtures over La- and
           Ce-doped FeMo catalysts
    • Authors: Anita Borowiec; Aleksandra Lilić; Jean-Charles Morin; Jean-François Devaux; Jean-Luc Dubois; Simona Bennici; Aline Auroux; Mickaël Capron; Franck Dumeignil
      Pages: 149 - 157
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Anita Borowiec, Aleksandra Lilić, Jean-Charles Morin, Jean-François Devaux, Jean-Luc Dubois, Simona Bennici, Aline Auroux, Mickaël Capron, Franck Dumeignil
      The acrolein production from methanol and ethanol mixtures over iron-molybdate-based catalysts was studied. The reaction to acrolein can be described by two successive steps: the first consists on the oxidation of both alcohols into their corresponding aldehydes and the second step is the subsequent aldol condensation of the as-formed aldehydes. The iron-molybdate catalysts were modified by doping with La and Ce (1%mol) in order to improve the aldol condensation step of the process. Series of catalysts were thus synthesized with different Mo/Fe ratios (i.e., 1.5, 2.0 and 2.5) and calcined at three different temperatures (i.e, 350 °C, 400 °C and 450 °C). The best catalytic performance was observed for FeMoCe2.0 (400 °C) for which the acrolein yield reached 42% (T = 320 °C, MetOH/EtOH = 1, GHSV = 3900 h−1). Furthermore, all the samples were characterised by TGA-DSC, HT-XRD, XPS, BET, LEIS, XRF, CO2-TPD, Pyridine (FTIR) and NH3 (calorimetry) adsorption. The increase in acrolein yield observed upon La and Ce doping was attributed to acid/base properties modification.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.076
      Issue No: Vol. 237 (2018)
       
  • Efficient n+p-Si photocathodes for solar H2 production catalyzed by Co-W-S
           and stabilized by Ti buffer layer
    • Authors: Ronglei Fan; Guanping Huang; Yongjie Wang; Zetian Mi; Mingrong Shen
      Pages: 158 - 165
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Ronglei Fan, Guanping Huang, Yongjie Wang, Zetian Mi, Mingrong Shen
      Photoelectrochemical (PEC) water splitting is regarded as a promising route to produce sustainable hydrogen fuel using sunlight and water as sole inputs. Si is one of the most promising potential materials for PEC photocathode, while developing highly active non-precious catalysts and stable semiconductor/catalyst interface is critical to bring solar water splitting into reality. Herein, we reported a cheap and effective strategy based on a wet chemical method to integrate WS2 and Co-doped WS2 (Co-W-S) onto n+p-Si as noble metal−free catalysts for H2 production. Co-W-S/n+p-Si photocathode exhibited much better PEC performance, resulting from the Co-W-S catalyst which has more electrochemically active sites and better electrical conductivity. A thin Ti interlayer between Co-W-S and Si was inserted to further optimize the PEC performance, especially the stability of the photocathode. As a result, an onset potential of 0.36 V vs. RHE, a photocurrent of 30.4 mA/cm2 at 0 V vs. RHE and an energy conversion efficiency of 4.0% were obtained under simulated AM1.5 G illumination, along with a long-term stability for 6 days of continuous PEC reaction.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.083
      Issue No: Vol. 237 (2018)
       
  • Hydrodeoxygenation of pinyon-juniper catalytic pyrolysis oil using red
           mud-supported nickel catalysts
    • Authors: Hossein Jahromi; Foster A. Agblevor
      Pages: 1 - 12
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Hossein Jahromi, Foster A. Agblevor
      Red mud (RM) is an alkaline waste generated in the Bayer process of alumina production. In the present study red mud supported nickel catalysts (Ni/RM) were prepared at different concentrations of nickel (10, 20, 30, 40, 50, and 65 wt.%) and used to hydrodeoxygenate (HDO) pinyon-juniper (PJ) catalytic pyrolysis oil. Increasing the nickel content improved the activity of Ni/RM catalysts for HDO reactions. Maximum organic liquid yield (68.6%) was obtained when 40%Ni/RM was used. The upgraded oil had oxygen content of 1.35 wt.% and higher heating value of 45.77 MJ/kg compared to 24.88 wt.% and 28.41 MJ/kg, respectively, for the crude oil. For comparison, commercial Ni/SiO2-Al2O3 was also evaluated in HDO experiments. The HDO oil properties obtained using 40%Ni/RM at reaction temperature of 400 °C was similar to that of commercial Ni/SiO2-Al2O3 at reaction temperature of 450 °C. However, the organic liquid yield was much higher for 40%Ni/RM (68.6%) compared to the commercial Ni/SiO2-Al2O3 (41.8%). The commercial Ni/SiO2-Al2O3 produced more gas (27.6%) than the 40%Ni/RM (16.4%) and the coke yields for the commercial catalyst and Ni/RM catalyst were 7.3% and 4.2% respectively. Overall, application of Ni/RM improved HDO reactions and reduced cracking and coke formation compared to commercial Ni/SiO2-Al2O3.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.008
      Issue No: Vol. 236 (2018)
       
  • Catalytic co-aromatization of methane and heptane as an alkane model
           compound over Zn-Ga/ZSM-5: A mechanistic study
    • Authors: Qingyin Li; Peng He; Jack Jarvis; Amit Bhattacharya; Xiaohui Mao; Aiguo Wang; Guy M. Bernard; Vladimir K. Michaelis; Hongbo Zeng; Lijia Liu; Hua Song
      Pages: 13 - 24
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Qingyin Li, Peng He, Jack Jarvis, Amit Bhattacharya, Xiaohui Mao, Aiguo Wang, Guy M. Bernard, Vladimir K. Michaelis, Hongbo Zeng, Lijia Liu, Hua Song
      The joint conversion of methane and heptane, a model compound of paraffin-rich raffinate oil, over a Zn-Ga modified zeolite catalyst has been investigated at various reaction times. In comparison with the performance from a N2 environment, the introduction of methane highly promotes the formation of light aromatic compounds with a single phenyl ring, and increased carbon number and substitution index of chemical constituents formed are indicative of methane incorporation into the liquid product. In addition, with prolonged time, the interaction between catalyst and methane molecules is enhanced. Through cleavage of methane molecules, the formed moieties likely participate in the aromatization reaction, which results in the growth of larger aromatic components through further condensation. According to the NMR spectra, witnessing methane engagement into the phenyl carbon and alkyl carbon sites of the formed liquid aromatics along with increasing reaction time is evidenced 13C-methane incorporation into aromatics. The excellent catalytic performance of Zn-Ga/ZSM-5 might be ascribed to the greatly dispersed metal species on the catalyst surface as well as a certain amount of medium and weak acid sites. With regards to the spent catalyst, the presence of methane could inhibit the aggregation of loaded active metals and coke formation during the co-aromatization process. The elucidation on the co-conversion of methane and high alkane provides great potential for the utilization of natural gas resources and intermediates formed from petrochemical industries.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.006
      Issue No: Vol. 236 (2018)
       
  • Cux-Nb1.1-x (x = 0.45, 0.35, 0.25, 0.15) bimetal oxides catalysts for the
           low temperature selective catalytic reduction of NO with NH3
    • Authors: Sher Ali; Liqiang Chen; Zhibin Li; Tianrui Zhang; Rui Li; Syed ul Hasnain Bakhtiar; Xuesong Leng; Fulong Yuan; Xiaoyu Niu; Yujun Zhu
      Pages: 25 - 35
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Sher Ali, Liqiang Chen, Zhibin Li, Tianrui Zhang, Rui Li, Syed ul Hasnain Bakhtiar, Xuesong Leng, Fulong Yuan, Xiaoyu Niu, Yujun Zhu
      The Cu x -Nb1.1- x (x = 0.45, 0.35, 0.25, 0.15) bimetal oxides catalysts were synthesized through citric acid method and used in the selective catalytic reduction (SCR) of NO with NH3. The relationship among the catalytic performances, the acid/redox properties and the structures of the binary oxides systems was explored through different characterization techniques including XRD, H2-TPR, BET, NO-TPD, NH3-TPD, XPS and in situ DRIFTS. The characterization results point out that the ratio of Cu to Nb has great influence on the activity of NH3-SCR reaction. Different catalytic activities of Cu x -Nb1.1- x (x = 0.45, 0.35, 0.25, 0.15) mixed oxides could be attributed mainly to surface area, acid amount, the adsorption and activation of NH3 and redox ability of the corresponding catalyst. Among these Cu x -Nb1.1- x (x = 0.45, 0.35, 0.25, 0.15) oxides catalysts, the Cu0.25-Nb0.85 catalyst exhibited the complete NO conversion in a reaction temperature range of 180-330 °C, together with near 100% N2 selectivity and remarkable SO2/H2O resistance. Moreover, the Cu0.25-Nb0.85 catalyst still exhibited wide activity temperature window of 185-380 °C at above 90% NO conversion even in the presence of 5% H2O under high GHSV of 70,000 h-1. Thus, it can be summarized from the above results that Cu0.25-Nb0.85 can be considered as excellent catalyst for NH3-SCR of NO.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.014
      Issue No: Vol. 236 (2018)
       
  • On the promotional effect of Cu on Pt for hydrazine electrooxidation in
           alkaline medium
    • Authors: Rudy Crisafulli; Vanine V. Silva de Barros; Francisca E. Rodrigues de Oliveira; Thairo de Araújo Rocha; Sabrina Zignani; Lorenzo Spadaro; Alessandra Palella; José A. Dias; José J. Linares
      Pages: 36 - 44
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Rudy Crisafulli, Vanine V. Silva de Barros, Francisca E. Rodrigues de Oliveira, Thairo de Araújo Rocha, Sabrina Zignani, Lorenzo Spadaro, Alessandra Palella, José A. Dias, José J. Linares
      Pt/C and PtCu/C electrocatalysts with nominal Pt:Cu atomic ratios of 75:25, 50:50, and 25:75 were prepared using N2H4 as reducing agent and carbon black Vulcan XC-72R as support. The obtained materials were physically characterized by X-ray diffraction, Energy-Dispersive X-ray analysis, Transmission Electron Microscopy images, X-ray Photoelectron Spectroscopy (XPS), and Temperature-Programmed Reduction analysis. Cyclic voltammetry, linear sweep voltammetry, and chronoamperometry (TPR) measurements were carried out in a three-electrode glass cell to evaluate the electrochemical activity towards hydrazine electrooxidation in alkaline medium along with single-cell direct hydrazine fuel cell (DHFC) tests. The actual composition of the electrocatalysts evidenced a slightly lower Cu fraction compared to the nominal one. The X-ray diffractograms of the electrocatalysts showed the typical face-centered cubic structure of Pt alloys, with the highest fraction of Cu alloyed to Pt being achieved with the almost equiatomic catalyst. An important fraction of the remaining non-alloyed Cu is in the form of a copper oxide, as evidenced by XPS and TPR measurements. The electrochemical tests evidenced that the coexistence of part of the Cu alloyed with Pt and copper oxide achieved in the PtCu/C electrocatalysts enhances the performance compared to Pt/C. In particular, the optimum formulation is attained by the Pt53Cu47/C electrocatalyst, allowing maximization of the electrocatalytic activity towards hydrazine electrooxidation and the single-cell performance at 60 and 80 °C.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.016
      Issue No: Vol. 236 (2018)
       
  • Fabrication of graphitic-C3N4 quantum dots/graphene-InVO4 aerogel hybrids
           with enhanced photocatalytic NO removal under visible-light irradiation
    • Authors: Jundie Hu; Dongyun Chen; Najun Li; Qingfeng Xu; Hua Li; Jinghui He; Jianmei Lu
      Pages: 45 - 52
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Jundie Hu, Dongyun Chen, Najun Li, Qingfeng Xu, Hua Li, Jinghui He, Jianmei Lu
      A new 3D aerogel of CNQDs/GO-InVO4 (CNQDs = graphitic C3N4 quantum dots, GO = graphene oxide) with porous layered structure is fabricated successfully. The stable and recyclable macro-material is found to be highly suitable for practical application. CNQDs with an average diameter of 3.0 nm are prepared through the exfoliation of bulk g-C3N4 step by step, and are decorated on the surface of GO uniformly by electrostatic, ππ stacking and hydrogen-bonding interactions. The CNQDs/GO are wrapped tightly around cubic InVO4, resulting in the immediate formation of a 3D aerogel with a heterostructure. The synergistic heterojunction exhibit a powerful photocatalytic effect for the removal of NO at the ppb-level (600 ppb) under visible-light irradiation, with a maximum efficiency up to 65%. A Z-scheme photocatalytic mechanism is proposed based on ESR experiments and calculation of the energy bands.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.04.080
      Issue No: Vol. 236 (2018)
       
  • Exceptional synergistic enhancement of the photocatalytic activity of SnS2
           by coupling with polyaniline and N-doped reduced graphene oxide
    • Authors: Fen Zhang; Yongcai Zhang; Geshan Zhang; Zhanjun Yang; Dionysios D. Dionysiou; Aiping Zhu
      Pages: 53 - 63
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Fen Zhang, Yongcai Zhang, Geshan Zhang, Zhanjun Yang, Dionysios D. Dionysiou, Aiping Zhu
      Effective enhancement of the separation and transfer of photogenerated electrons and holes of semiconductor photocatalysts is key to increase their photocatalytic efficiency. This study aims at improving the photocatalytic performance of visible-light-responsive, CdI2-type layered SnS2 by employing good conductivity N-doped reduced graphene oxide (NRG) and polyaniline (PANI) as the receptors and transporters of photogenerated electrons and holes, respectively. PANI/SnS2/NRG ternary composites were prepared by a three-step method, and the optimum conditions for preparing the most efficient product were explored. The photocatalytic experiments demonstrated that the PANI/SnS2/NRG ternary composite prepared under the optimum conditions (PANI/SnS2/NRG-2%) had markedly higher photocatalytic activity than SnS2 nanoplates, SnS2/PANI and SnS2/NRG binary composites in the reduction of aqueous Cr(VI) under the irradiation of visible-light (λ > 420 nm). Based on comparison of the photoabsorption, photoluminescence and electrochemical impedance properties of PANI/SnS2/NRG, SnS2/PANI and SnS2, it was thought that the coupling of SnS2 with both PANI and NRG had synergistic effects in increasing the absorption of visible-light as well as the separation and transfer of photogenerated electrons and holes, which contributed to the exceptionally high photocatalytic activity of PANI/SnS2/NRG ternary composite. Moreover, it was discovered that the photocatalytic reduction of Cr(VI) over PANI/SnS2/NRG-2% was dominantly through the reduction by photogenerated electrons, whereas both photogenerated electron and superoxide anion radical (O2 –) reduction played important roles in the photocatalytic reduction of Cr(VI) over SnS2. Besides, the influences of photocatalytic testing conditions (including starting pH and concentration of Cr(VI) solution, and dosage of photocatalyst) on the efficiency of PANI/SnS2/NRG-2% in treatment of aqueous Cr(VI) were also examined.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.002
      Issue No: Vol. 236 (2018)
       
  • In situfabrication of hierarchically porous g-C3N4 and understanding on
           its enhanced photocatalytic activity based on energy absorption
    • Authors: Yudong Li; Zhaohui Ruan; Yanzhen He; Junzhuo Li; Kunqiao Li; Yanqiu Jiang; Xianzhu Xu; Yuan Yuan; Kaifeng Lin
      Pages: 64 - 75
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Yudong Li, Zhaohui Ruan, Yanzhen He, Junzhuo Li, Kunqiao Li, Yanqiu Jiang, Xianzhu Xu, Yuan Yuan, Kaifeng Lin
      A novel strategy is proposed to in situ synthesize hierarchically porous g-C3N4 foam (FCN) with no carbon residue by low-cost polyurethane sponge as single template. The porous system consists of interconnected micron- (1–2 μm) and nano-scale (20–80 nm) pores, which is usually constructed tediously. For visible light catalysis, the FCN with unique hierarchical pores possesses higher efficiency for H2 generation (8 times) and phenol degradation (4 times) over pristine g-C3N4 due to the increased BET surface area, accelerated mass transfer and improved efficiency of exciton generation and dissociation, which all derive from the hierarchical pore system. Further, an optical simulation is initially adopted to illustrate the effect of the hierarchical porosity with micron- and nano-scale pores on the ability of light absorption and penetration over FCN and an energy-absorption-based explanation is proposed to deeply explain the enhanced photocatalytic activity, which opens a window to directly understand the relationship of the enhanced photocatalytic activities and absorbed light energy increased by the hierarchical pores system.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.04.082
      Issue No: Vol. 236 (2018)
       
  • Flowing nitrogen atmosphere induced rich oxygen vacancies overspread the
           surface of TiO2/kaolinite composite for enhanced photocatalytic activity
           within broad radiation spectrum
    • Authors: Chunquan Li; Zhiming Sun; Ankang Song; Xiongbo Dong; Shuilin Zheng; Dionysios D. Dionysiou
      Pages: 76 - 87
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Chunquan Li, Zhiming Sun, Ankang Song, Xiongbo Dong, Shuilin Zheng, Dionysios D. Dionysiou
      Natural minerals are generally accepted as one of the most suitable carriers to support TiO2 in photocatalytic and other applications because of their abundance, low cost, large surface area, and easy recyclability. Hence, in this work, a novel 0D/2D TiO2/kaolinite composite endowed with presence of oxygen vacancies and surface defect sites was synthesized through a mild sol-gel method combining with nitrogen induction. Ciprofloxacin (CIP) was taken as the main target organic pollutant to study the photocatalytic performance of the synthesized catalyst. The results showed that the nitrogen treated TiO2/kaolinite composite exhibited improving degradation performance for adsorption-photocatalytic elimination of CIP within broad radiation spectrum (200–800 nm). The synthesized composite exhibited enhanced reaction rate constant which is nearly 7.00, 2.54 and 3.13 times higher than that of bare TiO2 treated with air under UV, solar, and visible light, respectively. Moreover, the newly prepared composite also exhibited significant enhancement towards the removal of formaldehyde under both UV and visible light. Radical scavenger experiments and ESR results indicated that holes should be the main oxidizing species within broad spectrum in the degradation system. The enhanced activity of nitrogen treated composite is mainly attributed to the induced oxygen vacancies as well as the intimate interface contact between TiO2 and kaolinite, resulting in smaller grain size, higher light absorption ability, and faster carrier separation efficiency. It is expected that this high-efficiency composite photocatalyst based on natural minerals will be a promising candidate for the elimination of pharmaceutical and personal care products and volatile organic compounds within broad radiation spectrum.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.04.083
      Issue No: Vol. 236 (2018)
       
  • Nanostructured PdPt nanoparticles: evidences of structure/performance
           relations in catalytic H2 production reactions
    • Authors: Matteo Monai; Tiziano Montini; Emiliano Fonda; Matteo Crosera; Juan José Delgado; Gianpiero Adami; Paolo Fornasiero
      Pages: 88 - 98
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Matteo Monai, Tiziano Montini, Emiliano Fonda, Matteo Crosera, Juan José Delgado, Gianpiero Adami, Paolo Fornasiero
      A widespread approach to modulate the performances of heterogeneous catalysts is the use of bimetallic nanoparticles (NPs) as the active phase. However, studying the relationship between the NPs structure and catalytic properties requires well-defined systems, having uniform composition, size and nanostructure, which cannot be achieved by traditional methods (e.g. impregnation). Here, we developed wet-chemistry synthetic routes to prepare PdPt NPs or Pt-core@Pd-shell NPs of small size and well-controlled composition and structure, protected by mercaptoundecanoic acid (MUA) moieties. The pristine NPs were tested for H2 production by NH3BH3 hydrolysis, in order to systematically investigate the effect of composition and of synthetic route on the activity of the systems. Depending on the preparation method, two distinct trends of activity were observed, rationalized in terms of the extent of surface functionalization by MUA. The MUA protective layer was found to effectively stabilize the NPs dispersion while maintaining high activity in certain cases (Pt-rich NPs), and was demonstrated to be essential for catalyst recycling. In order to further study structure-activity relationships of PdPt NPs after ligand removal, nanostructured PdPt@CeO2-based catalysts were prepared by self-assembly route. Regardless of the starting NPs structure (alloy or core-shell), similar water gas shift reaction performances were observed, due to the structural rearrangements occurring upon oxidation and reduction thermal treatments, which led to the formation of Pt-rich core@PdPt-shell under reducing conditions.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.019
      Issue No: Vol. 236 (2018)
       
  • Carbon nitride with electron storage property: Enhanced exciton
           dissociation for high-efficient photocatalysis
    • Authors: Zhenxing Zeng; Xie Quan; Hongtao Yu; Shuo Chen; Yaobin Zhang; Huimin Zhao; Shushen Zhang
      Pages: 99 - 106
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Zhenxing Zeng, Xie Quan, Hongtao Yu, Shuo Chen, Yaobin Zhang, Huimin Zhao, Shushen Zhang
      Excitonic effect, originated from the strong Coulomb attraction between electron and hole, plays an important role in the photocatalytic process of polymeric materials but has been long ignored. In view point of hot-carriers generation, the dissociation of Frenkel excitons is proposed as an effective way to improve the photocatalytic performance of polymeric photocatalysts. Herein, by taking graphitic carbon nitride (g-C3N4) as an example, we verify that endowing g-C3N4 with electron storage ability can facilitate exciton dissociation by extracting electrons from bound electron-hole couples around the electron stotage sites, therefore enhancing the hot-carriers harvest and suppressing the charge recombination. Benefiting from these advantages, the as-prepared material demonstrates excellent photocatalytic performance for both H2 evolution and H2O2 generation. As a result, the apparent quantum yield (AQY) for H2 evolution at 420 nm reaches 55%, which is much higher than most of the reported polymeric materials. The study described here offers a new way for designing advanced polymeric photocatalysts toward high performance solar energy conversion via excitonic engineering.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.003
      Issue No: Vol. 236 (2018)
       
  • An Effective Way to Improve Bifunctional Electrocatalyst Activity of
           Manganese Oxide via Control of Bond Competition
    • Authors: Bohyun Kang; Xiaoyan Jin; Seung Mi Oh; Sharad B. Patil; Min Gyu Kim; Sun Hee Kim; Seong-Ju Hwang
      Pages: 107 - 116
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Bohyun Kang, Xiaoyan Jin, Seung Mi Oh, Sharad B. Patil, Min Gyu Kim, Sun Hee Kim, Seong-Ju Hwang
      A critical role of bond competition in tailoring Mn valence state and bifunctional electrocatalyst activity of manganese oxide is evidenced by the remarkable improvement of the electrocatalyst activity of α-MnO2 upon the partial substitution of electronegative Ru4+ ion. The replacement of Mn4+ ion with more electronegative Ru4+ one is quite effective in weakening adjacent (Mn−O) bonds in terms of bond competition, leading to the stabilization of Jahn-Teller active Mn3+ species, as well as in providing electrocatalytically active Ru sites. The resulting Ru-substituted α-Mn1−xRuxO2 nanowires show much higher electrocatalyst activities for both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) than does the physical mixture of α-MnO2 and RuO2, indicating the main role of (Mn−O) bond covalency in the optimization of the bifunctional electrocatalyst activity of manganese oxide. The present study underscores that, like the previous strategy of structural disorder enhancement, the substitution of highly electronegative cation can provide a novel efficient way of improving the electrocatalyst performance of manganese oxide via the bond competition between adjacent (Ru−O) and (Mn−O) bonds.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.010
      Issue No: Vol. 236 (2018)
       
  • Hematite photoanodes with size-controlled nanoparticles for enhanced
           photoelectrochemical water oxidation
    • Authors: Amira Y. Ahmed; Mahmoud G. Ahmed; Tarek A. Kandiel
      Pages: 117 - 124
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Amira Y. Ahmed, Mahmoud G. Ahmed, Tarek A. Kandiel
      The synthesis of hematite photoanodes with size-controlled nanoparticles is challenging due to the difficulty in finding the appropriate morphology-directing agents. In this paper, Ba2+ and Sr2+ ions were successfully employed to synthesize hematite photoanodes with size-controlled nanoparticles using a facile chemical bath deposition method. The synthesized electrodes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), inductively coupled plasma-optical emission spectrometry (ICP-OES), (photo)electrochemical impedance spectroscopy ((P)EIS), X-ray photoelectron spectroscopy (XPS) and intensity modulated photocurrent spectroscopy (IMPS) measurements. It was found that the average diameter of hematite nanoparticles is decreased by a factor of 13% and 35% by the addition of Ba2+ and Sr2+ ions into the chemical bath, respectively. In agreement with these results, the electroactive surface area of Ba- and Sr-modified hematite electrodes increased by 2.4 and 3.2 times, respectively, in comparison with that of bare hematite. The photoelectrochemical measurements under the standard illumination conditions revealed that the generated photocurrent at 1.23 V vs. RHE on Ba- and Sr-modified hematite photoanodes is 2.6 and 3 times higher than that of bare hematite, respectively. Moreover, the photocurrent onset potential for water oxidation on Ba- and Sr-modified hematite photoanodes was shifted cathodically by about 150 and 220 mV, respectively. Based on these results, a good correlation between the photocurrent and the electroactive surface area was observed at high bias potential (i.e., 1.23 V vs. RHE) evincing that the photocurrent enhancement can be readily attributed to the enhanced electroactive surface area. The cathodic shift in the photocurrent onset potential of water oxidation was elucidated, however, by the higher density of surface states and the higher rate constant of charge transfer as proven by the PEIS and IMPS measurements, respectively.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.04.073
      Issue No: Vol. 236 (2018)
       
  • Synthesis of rGO-doped Nb4O5–TiO2 nanorods for photocatalytic and
           electrochemical energy storage applications
    • Authors: Rajesh Rajagopal; Kwang-Sun Ryu
      Pages: 125 - 139
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Rajesh Rajagopal, Kwang-Sun Ryu
      A novel (Nb4O5–TiO2)@rGO nanocomposite was synthesized using a Na+ ion intercalation-assisted hydrothermal technique and examined its photocatalyst dye degradation and supercapacitor applications. The synthesized (Nb4O5–TiO2) nanorods were segregated by well dispersed reduced graphene oxide with different weight ratios. A strong interaction was observed between the (Nb4O5–TiO2) to rGO nanosheets, even with high rGO content (5 wt. %). Experiments examining the photocatalytic degradation of methylene blue suggested that the (Nb4O5–TiO2)@ 5rGO nanocomposites exhibit excellent charge carrier mobility with a higher methylene blue degradation rate (92%) than Nb4O5–TiO2 nanorods and other (Nb4O5–TiO2)@rGO nanocomposites under ultraviolet and visible light irradiation. On the other hand, the (Nb4O5–TiO2)@ 5rGO nanocomposite exhibited excellent electrochemical performance with high specific capacitance (365 F g−1), long cycling stability (∼100% capacitance retention after 1000 cycles), and good rate capability (70% capacitance retention at 25 A g−1). In addition, the photocatalytic and supercapacitor efficiency of the (Nb4O5–TiO2)@rGO nanocomposite increased gradually with increasing amount of rGO in the composite. These features collectively demonstrated the high rate of photocatalytic degradation efficiency and good energy storage performance of the (Nb4O5–TiO2)@ 5rGO nanocomposite, which suggests a new route for large scale applications in energy and environmental fields.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.03.112
      Issue No: Vol. 236 (2018)
       
  • Photo-switchable pure water splitting under visible light over nano-Pt@P25
           by recycling scattered photons
    • Authors: Wenjian Fang; Zhen Qin; Junying Liu; Zhidong Wei; Zhi Jiang; Wenfeng Shangguan
      Pages: 140 - 146
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Wenjian Fang, Zhen Qin, Junying Liu, Zhidong Wei, Zhi Jiang, Wenfeng Shangguan
      Visible light absorption peak from near-field dielectric scattering was observed in case of Pt nanoparticles directly supported on P25. This absorbed scattered light could drive visible-light photocatalytic pure water splitting (λ>420 nm). It is interesting that the roles of Pt and P25 in photocatalytic hydrogen generation were switchable under different irradiation conditions. Under UV–vis irradiation, P25 represented a photocatalyst while Pt was cocatalyst. Under visible light irradiation (λ>420 nm), Pt would prefer to act as a photocatalyst while P25 was analogous to cocatalyst. Moreover, defects (Ti3+ or VO) on the surface of Pt/P25 would be generated under UV irradiation. These defects are similar with a sacrificial agent to consume photogenerated holes, which are necessary for visible-light-drive photocatalytic pure water splitting.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.023
      Issue No: Vol. 236 (2018)
       
  • Tungsten carbide electrocatalysts prepared from metallic tungsten
           nanoparticles for efficient hydrogen evolution
    • Authors: S. Emin; C. Altinkaya; A. Semerci; H. Okuyucu; A. Yildiz; P. Stefanov
      Pages: 147 - 153
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): S. Emin, C. Altinkaya, A. Semerci, H. Okuyucu, A. Yildiz, P. Stefanov
      Pyrolysis of hexacarbonyl tungsten, W(CO)6, in 1-octadecene has been used to prepare colloidal tungsten, W, nanoparticles (NPs). The obtained W NPs has been spin-coated on graphite (C) electrodes. Heat treatment of the W/C electrodes at elevated temperatures (≥900 °C) allows the preparation of metallic W and tungsten carbide (W2C@WC) thin films. The obtained W2C@WC electrodes were used for hydrogen evolution studies (HER) in 0.5 M H2SO4. Cyclic voltammetry tests for 1000 cycles showed that W2C@WC exhibit long term stability without significant drop in current density. The overpotential defined at 10 mA/cm2 is 310 mV vs. RHE giving an excellent catalytic activity for HER. Materials characterization has been achieved using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). Here, EIS studies were used to access the charge-transfer resistance of tungsten carbide electrodes.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.026
      Issue No: Vol. 236 (2018)
       
  • A novel strategy to develop non-noble metal catalyst for CO2
           electroreduction: Hybridization of metal-organic polymer
    • Authors: Yeongdong Mun; Kyeounghak Kim; Seongbeen Kim; Seunghyun Lee; Seonggyu Lee; Sujeong Kim; Wonyong Choi; Soo-kil Kim; Jeong Woo Han; Jinwoo Lee
      Pages: 154 - 161
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Yeongdong Mun, Kyeounghak Kim, Seongbeen Kim, Seunghyun Lee, Seonggyu Lee, Sujeong Kim, Wonyong Choi, Soo-kil Kim, Jeong Woo Han, Jinwoo Lee
      Electrochemical CO2 reduction reaction (CO2RR) has attracted a lot of interest as a highly potential CO2 utilization system. Due to the high overpotential in CO2RR, an effective catalyst is required. We report a metal-organic hybrid catalyst (Co-PPy-C), which consists of Co and polypyrrole, as a highly active electrocatalyst for CO2RR. Co-PPy-C exhibited high Faradaic efficiency and metal mass activity for CO production at low overpotential region. By density functional theory calculations, it was revealed that the catalytic site is the Co surface on which the deprotonated pyrrolic functionality in polypyrrole is adsorbed, and that the facile production of CO from CO2 is due to the CO adsorption on the Co being weakened by the charge transfer from the Co surface to the polypyrrole. This work reports a new and active non-noble metal catalyst for CO2RR, and provides the strategy of hybridization of metal and organic material to modify or enhance the catalytic activity of metal for CO2RR.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.025
      Issue No: Vol. 236 (2018)
       
  • Methanation of CO2 over alkali-promoted Ru/TiO2 catalysts: II. Effect of
           alkali additives on the reaction pathway
    • Authors: Paraskevi Panagiotopoulou
      Pages: 162 - 170
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Paraskevi Panagiotopoulou
      The effect of alkali (Li, Na, K, Cs) promotion of TiO2 on the CO2 hydrogenation pathway has been investigated over 0.5%Ru/TiO2 and 5%Ru/TiO2 catalysts, employing in situ FTIR spectroscopy (DRIFTS) and transient-mass spectrometry techniques. In the case of 0.5%Ru/TiO2 catalysts, characterized by well-dispersed Ru particles, specific activity and selectivity toward methane increases significantly with the addition of suitable amount of alkalis. The nature and population of Ru-bonded carbonyl species, formed on the surface of 0.5%Ru/TiO2 catalyst under CO2 hydrogenation conditions, varies significantly upon alkali promotion. The population of reactive Rux-CO species, which has been previously found to be direct methane precursors, increases in the presence of alkalis following a trend similar to that of specific activity. Results of DRIFT and mass spectrometry experiments provide evidences that alkali promotion enhances the dissociative adsorption of CO and hydrogenation of the so formed surface carbon to methane, which seems not to be operable over the unpromoted 0.5%Ru/TiO2 catalyst. In the case of 5%Ru/TiO2 catalysts, characterized by large Ru particles, both CO2 methanation activity and the nature/population of intermediate surface species seems not to be significantly affected by the presence of sodium. It is suggested that the structure sensitivity of the reaction predominates to the effect of alkali promotion and therefore, CO2 methanation activity cannot be further improved.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.028
      Issue No: Vol. 236 (2018)
       
  • Perspective intermediate temperature ceria based catalysts for CO
           oxidation
    • Authors: Igor V. Zagaynov; Alexander V. Naumkin; Yuriy V. Grigoriev
      Pages: 171 - 175
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Igor V. Zagaynov, Alexander V. Naumkin, Yuriy V. Grigoriev
      The work is focused on the investigation of the influence of ternary metal oxide promoted ceria based materials (Cu-Mn-Zr-Ce-O) with various Cu/Mn molar ratios on the physicochemical and catalytic properties for CO oxidation in model reaction. It is shown that no diffraction peaks corresponding to coper and/or manganese oxides were indicated, ensuring the formation of solid solution based on ceria. The crystallite size of all samples is about 7–9 nm, and did not depend on the Cu/Mn ratio. The optimum catalyst composition was Cu0.08Mn0.02(Zr0.1)Ce0.9O2. To understand the feature of this optimum catalyst composition the investigation of structure and morphological characterization by XRD, TEM, HR TEM, TG-DSC, FTIR, Raman, and XPS of samples was carried out.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.027
      Issue No: Vol. 236 (2018)
       
  • Visible-light driven oxidative coupling of amines to imines with high
           selectivity in air over core-shell structured CdS@C3N4
    • Authors: Yong Xu; Yong Chen; Wen-Fu Fu
      Pages: 176 - 183
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Yong Xu, Yong Chen, Wen-Fu Fu
      A core-shell structured CdS@C3N4 photocatalyst with a 4 nm thick shell was prepared using self-assembly, and its structure, composition and morphology were characterized in detail. The hybrid visible-light catalyst exhibited a high photocatalytic performance for oxidative coupling of amines under atmospheric conditions, and robust product selectivity up to >99% for photodriven oxidation of various amines to corresponding imines was achieved. It was confirmed using Hammett-type plots and radical trapping experiments that steric effects and the formation of •O2 − are critical for photocatalytic conversion of the investigated substrates, and the related catalytic mechanism is presented.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.03.098
      Issue No: Vol. 236 (2018)
       
  • Fabrication of perovskite-type macro/mesoporous La1-xKxFeO3-δ nanotubes
           as an efficient catalyst for soot combustion
    • Authors: Fan Fang; Nengjie Feng; Lei Wang; Jie Meng; Geng Liu; Peng Zhao; Pengfei Gao; Jing Ding; Hui Wan; Guofeng Guan
      Pages: 184 - 194
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Fan Fang, Nengjie Feng, Lei Wang, Jie Meng, Geng Liu, Peng Zhao, Pengfei Gao, Jing Ding, Hui Wan, Guofeng Guan
      Perovskite-type macro/mesoporous nanotube shows large specific surface area and high utilization of catalytic sites, which gives rise to the enhancement of catalytic activity and broaden their application. In this work, perovskite-type La1-xKxFeO3-δ nanotubes were prepared for efficient soot oxidation by a simple electrospinning technique following calcination. The as-prepared samples were characterized by XRD, FI-IR, FE-SEM, TEM, XPS, N2 adsorption-desorption, H2-TPR and O2-TPD techniques to investigate the physical-chemical properties. A certain amount of K+ doped in to LaFeO3-δ nanotubes sample could inhibit the growth of crystallites during the calcination at a high temperature, which could prevent the destruction of macro/mesoporous tubular structure and contribute to the more contact between soot particles and active sites. Meanwhile, it could also bring about the higher oxygen vacancy density responsible for the enhancement of redox abilities. However, excessive doping of K+ could lead to the collapsing of macro/mesoporous tubular structure, ascribable to the formation of low-melting compounds or eutectics with other components of the catalyst, which would have a negative influence on the catalytic performance. The performance for soot catalytic oxidation was evaluated in a temperature programmed oxidation device using O2 (without or with NO) as oxidant. Among the as-prepared catalysts, the well-structured La0.8K0.2FeO3-δ nanotubes catalyst is the best candidate for soot removal.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.030
      Issue No: Vol. 236 (2018)
       
  • New operando method for quantifying the relative half-cycle rates of the
           NO SCR redox cycle over Cu-exchanged zeolites
    • Authors: W.P. Partridge; S.Y. Joshi; J.A. Pihl; N.W. Currier
      Pages: 195 - 204
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): W.P. Partridge, S.Y. Joshi, J.A. Pihl, N.W. Currier
      An operando experimental method for monitoring relative variations in half-cycle rates of the Cu redox-cycle model of selective-catalytic-reduction (SCR) is demonstrated, along with a kinetic model for predicting the same. Conversion inflections (CI) can occur at SCR onset within Cu/SCR catalysts; transient CI involves initial conversion growth to an intermediate value greater than exists at steady state (SS) before degrading to the SS value. While similar CI has been reported for Fe/SCR catalysts as being due to NH3 inhibition, Cu/SCR CI is inconsistent with a similar origin. Rather, Cu/SCR CI is due to imbalances in the redox-half-cycle rates, and will occur when reduction is faster than oxidation. The temporal CI shape varies with the redox-cycle kinetic parameters and model formulation, and can be used to study the same. We demonstrate the first measurements of dynamic half-cycle rate balancing at SCR onset, use CI and onset transients to study variations in half-cycle rates under Standard, Fast and NO2 SCR, and present the first redox-cycle model showing CI. The new operando method and model provides a basis for better understanding the SCR redox process, and determining the individual half-cycles kinetic model formulation and parameters.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.04.071
      Issue No: Vol. 236 (2018)
       
  • Constructing a novel Bi2SiO5/BiPO4 heterostructure with extended light
           response range and enhanced photocatalytic performance
    • Authors: Di Liu; Weibin Cai; Yonggang Wang; Yongfa Zhu
      Pages: 205 - 211
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Di Liu, Weibin Cai, Yonggang Wang, Yongfa Zhu
      To further extend the light response range of BiPO4 and meanwhile keep its strong photocatalytic oxidation ability, the design of a type-II heterojunction by coupling BiPO4 with a narrower band gap semiconductor of Bi2SiO5 as a novel and efficient photocatalytic catalyst has been successfully realized through a simple co-precipitate method. Moreover, under 365 nm UV light irradiation, pure BiPO4 shows no photo-activity, whereas the optimal Bi2SiO5/BiPO4 heterostructure exhibits highly enhanced photocatalytic activity than pure Bi2SiO5 in systems of photo-degradation over phenol and MB, which is 4.36 times and 1.13 times the values of pure Bi2SiO5. Experimental results reveal that the superior photocatalytic performance can be attributed to the synergetic effect of the evidently improved charge separation ability via the heterojunction, good crystallinity, expanded light absorbance and the moderate BET specific surface area.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.022
      Issue No: Vol. 236 (2018)
       
  • Synthesis of nitrogen and sulfur co-doped reduced graphene oxide as
           
    • Authors: Weiwei Han; Lulu Chen; Weiyu Song; Shaobin Wang; Xiaobin Fan; Yang Li; Fengbao Zhang; Guoliang Zhang; Wenchao Peng
      Pages: 212 - 221
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Weiwei Han, Lulu Chen, Weiyu Song, Shaobin Wang, Xiaobin Fan, Yang Li, Fengbao Zhang, Guoliang Zhang, Wenchao Peng
      Nitrogen and sulfur co-doped reduced graphene oxide (NS-rGO) was synthesized using a facile low temperature calcination method, which was then used as support and cocatalyst for the anchor of CdS. The obtained CdS/NS-rGO nanocomposites exhibit ultra-high photocatalytic activity for hydrogen evolution and 4-nitrophenol (4-NP) reduction under visible light (λ ≥ 420 nm). Their activity could also be adjusted by changing the doping amount of S and N, or by changing the ratios between CdS and NS-rGO. The optimum percentage of NS-rGO is 5 wt%, at which CdS/NS-rGO photocatalyst could achieve the highest H2 evolution rate of 1701 μmol h–1 g–1. Moreover, the reduction from 4-NP to 4-aminophenol (4-AP) could be completed within only 6 min over this optimized composite. NS-rGO here could provide more active sites as well as tune the band gap structure to increase the photo-activity. The density functional theory (DFT) calculations reveal that NS-rGO has a small Gibbs free energy for H* adsorption (ΔG H), which could increase the utilization efficency of photo-generated electrons for H2 generation. NS-rGO is therefore an idea alternate cocatalyst of noble metals for new photocatalysts development.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.021
      Issue No: Vol. 236 (2018)
       
  • Ultrathin two-dimensional BiOBrxI1-x solid solution with rich oxygen
           vacancies for enhanced visible-light-driven photoactivity in environmental
           remediation
    • Authors: Qiao Wang; Zhiquan Liu; Dongmei Liu; Guoshuai Liu; Min Yang; Fuyi Cui; Wei Wang
      Pages: 222 - 232
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Qiao Wang, Zhiquan Liu, Dongmei Liu, Guoshuai Liu, Min Yang, Fuyi Cui, Wei Wang
      Photocatalysis is intensively investigated for environmental remediation, but suffering from moderate efficiency toward the colorless persistent organic contaminants, the major category of organic pollutants in water environment. Herein, a novel series of oxygen vacancy-rich ultrathin two-dimensional BiOBrxI1-x solid solution nanosheets (BBI-x) were successfully constructed via a one-step solvothermal method. Under visible light irradiation, the optimal BiOBr0.85I0.15 sample (BBI-0.85) exhibited over 90% degradation efficiency of 4-chlorophenol (4-CP) within 30 min, which was 4.4, 10.9 and 5.9 times greater than that of pure BiOI nanosheets, pure BiOBr nanosheets and oxygen vacancy-poor BiOBr0.85I0.15 nanoplates, respectively. Also, this excellent photoactivity can expand to other colorless organic contaminants, such as bisphenol analogues and sulfonamides, verifying the universal applicability of BiOBrxI1-x. The enhanced activity can be ascribed to the synergistic effect of solid solution and oxygen vacancies. Formation of solid solution promotes visible-light harvesting and photogenerated charge carriers’ separation efficiency, as well as endows photoinduced holes with sufficient oxidation capacity, unambiguously confirmed by multiple optical and photoelectrochemical characterizations. Meanwhile, the oxygen vacancies induce an intermediate level near the Fermi level, narrowing the band gap energy and impeding the recombination of photogenerated charge carriers, as evidenced by density functional theory (DFT) analyses. This work could give ideas for the design of highly active photocatalysts toward sustainable solar-to-chemical energy conversion and environmental remediation.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.029
      Issue No: Vol. 236 (2018)
       
  • Rational design and facile in situ coupling non-noble metal Cd
           nanoparticles and CdS nanorods for efficient visible-light-driven
           photocatalytic H2 evolution
    • Authors: Bo Wang; Sha He; Wenhui Feng; Lulu Zhang; Xueyan Huang; Kaiqiang Wang; Shiying Zhang; Ping Liu
      Pages: 233 - 239
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Bo Wang, Sha He, Wenhui Feng, Lulu Zhang, Xueyan Huang, Kaiqiang Wang, Shiying Zhang, Ping Liu
      Non-noble metal Cd nanoparticles, as an efficient cocatalyst, are successfully constructed onto the surface of hexagonal CdS nanorods (CdS NRs) for the photocatalytic hydrogen evolution reaction by a facile in situ chemical reduction approach based on a thermal treatment process. The in situ introduction of Cd can significantly improve the photocatalytic H2 production performance of CdS NRs in sodium sulfide and sodium sulfite aqueous solutions under visible light irradiation. The superior electrical conductivity of metallic Cd and the intimate interfacial contact between Cd and CdS NRs are suggested to account for the enhanced light absorption intensity, more efficient charge separation, and faster interfacial charge migration, resulting in the dramatically promoted photocatalytic H2 production activity. This work provides a new route for the in situ deposition of Cd nanoparticles onto CdS and other Cd-containing semiconductor photocatalysts with desired morphologies.
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      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.005
      Issue No: Vol. 236 (2018)
       
  • The inhibition of hydrogen and oxygen recombination reaction by halogen
           atoms on over-all water splitting over Pt-TiO2 photocatalyst
    • Authors: Meng Wang; Wenlong Zhen; Bin Tian; Jiantai Ma; Gongxuan Lu
      Pages: 240 - 252
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Meng Wang, Wenlong Zhen, Bin Tian, Jiantai Ma, Gongxuan Lu
      Semiconductor photocatalysts for overall water splitting into H2 and O2 require metal cocatalyst, such as Pt, to catalyze H2 evolution efficiently. However, these metal cocatalysts can also catalyze hydrogen and oxygen recombination to form water. In this paper, we found that the pre-adsorbed halogen atom catalyst could inhibit the reverse reaction of water formation from H2 and O2 due to the decrease of adsorption energies of H2 and O2 on Pt. The adsorption energy decrease of H2 and O2 followed the order of F/Pt < Cl/Pt < I/Pt < Br/Pt. H2-TPD results exhibited similar dependence. This inhibition was achieved via the occupation of halogen atom on the Pt surface sites, and thereby the adsorption and activation of hydrogen and oxygen molecules were decreased. The occupation difference of halogen atoms are determined by radius of halogen ions, which further leads the different activity for H2 and O2 recombination. By inhibition of water formation reverse reaction, the over-all water splitting over various TiO2 photocatalysts has been achieved. Isotope experiments with D2O and H2 18O confirmed the over-all water splitting to H2 and O2. This study may help scientist to develop high-efficient photocatalyst for overall water splitting.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.031
      Issue No: Vol. 236 (2018)
       
  • Au-doped Ni/GDC as an Improved Cathode Electrocatalyst for H2O
           Electrolysis in SOECs
    • Authors: E. Ioannidou; Ch. Neofytidis; L. Sygellou; D.K. Niakolas
      Pages: 253 - 264
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): E. Ioannidou, Ch. Neofytidis, L. Sygellou, D.K. Niakolas
      The present work deals with the comparison between single electrolyte supported Solid Oxide Electrolysis Cells that comprise either a 3 wt.% Au-Ni/GDC or a Ni/GDC steam/hydrogen electrode. Specifically, their electrochemical performance was investigated for the H2O electrolysis reaction by varying the pH2O/pH2 ratio (from 1 to 9), the operating temperature (800-900 °C) and the applied current. Physicochemical characterization was also performed both in the form of powders and as half cells with ex-situ and in-situ techniques, such as SEM, BET, XPS and TGA, including specific measurements in the presence of H2O. Different structural and activity properties were observed for each cermet, where the cell comprising the 3Au-Ni/GDC electrode exhibited better electrochemical performance, especially at 850 °C and above, having lower polarization resistance. This improvement is ascribed to the formation of a surface Ni-Au solid solution, which causes weaker interaction of H2O and of the resulting adsorbed Oads species with the modified cermet. The outcome is an electrode with a lower degree of surface oxidation and increased “three phase boundaries” length, where the charge transfer and electrode processes are enhanced for the H2O electrolysis reaction.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.017
      Issue No: Vol. 236 (2018)
       
  • Constructing bio-templated 3D porous microtubular C-doped g-C3N4 with
           tunable band structure and enhanced charge carrier separation
    • Authors: Mohamad Azuwa Mohamed; M.F. M. Zain; Lorna Jeffery Minggu; Mohammad B. Kassim; Nor Aishah Saidina Amin; W.N. W. Salleh; Mohd Nur Ikhmal Salehmin; Mohd Faizal Md Nasir; Zul Adlan Mohd Hir
      Pages: 265 - 279
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Mohamad Azuwa Mohamed, M.F. M. Zain, Lorna Jeffery Minggu, Mohammad B. Kassim, Nor Aishah Saidina Amin, W.N. W. Salleh, Mohd Nur Ikhmal Salehmin, Mohd Faizal Md Nasir, Zul Adlan Mohd Hir
      For the first time, the bio-templated porous microtubular C-doped (BTPMC) g-C3N4 with tunable band structure was successfully prepared by simple thermal condensation approach using urea as precursors and kapok fibre which provides a dual function as a bio-templates and in-situ carbon dopant. Prior to the thermal condensation process, the impregnation strategies (i.e. direct wet and hydrothermal impregnation) of urea on the treated kapok fibre (t-KF) were compared to obtained well-constructed bio-templated porous microtubular C-doped g-C3N4. The details on a physicochemical characteristic of the fabricated samples were comprehensively analyze using X-ray diffraction (XRD), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), Field-emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), N2 adsorption-desorption, Thermogravimetric (TGA), and UV–vis spectroscopy. Our finding indicated that the hydrothermal impregnation strategy resulted in well-constructed microtubular structure and more carbon substitution in sp2-hybridized nitrogen atoms of g-C3N4 as compared to the direct wet impregnation. Also, compared to pure g-C3N4, the fabricated BTPMC g-C3N4 exhibited extended photoresponse from the ultraviolet (UV) to visible and near-infrared regions and narrower bandgap. The bandgap easily tuned with the increased t-KF loading in urea precursor which responsible for in-situ carbon doping. Moreover, as compared to pristine g-C3N4, dramatic suppression of charge recombination of the BTPMC g-C3N4 was confirmed through photoluminescence, photocurrent response, and electrochemical impedance spectroscopy. The resultants BTPMC g-C3N4 possesses more stable structure, promoted charge separation, and suitable energy levels of conduction and valence bands for photocatalysis application.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.037
      Issue No: Vol. 236 (2018)
       
  • Dry reforming of methane over CeO2-supported Pt-Co catalysts with enhanced
           activity
    • Authors: Zhenhua Xie; Binhang Yan; Shyam Kattel; Ji Hoon Lee; Siyu Yao; Qiyuan Wu; Ning Rui; Elaine Gomez; Zongyuan Liu; Wenqian Xu; Li Zhang; Jingguang G. Chen
      Pages: 280 - 293
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Zhenhua Xie, Binhang Yan, Shyam Kattel, Ji Hoon Lee, Siyu Yao, Qiyuan Wu, Ning Rui, Elaine Gomez, Zongyuan Liu, Wenqian Xu, Li Zhang, Jingguang G. Chen
      Dry reforming of methane provides opportunities of using CH4 and CO2 to produce syngas. The PtCo/CeO2 bimetallic catalyst shows higher activity and H2/CO ratio than the corresponding monometallic catalysts, mainly attributed to the synergistic effect of Pt-Co. Structural feature of the PtCo/CeO2 catalyst was revealed by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) of adsorbed CO and in situ techniques like X-ray diffraction (XRD), X-ray adsorption fine structure (XAFS) and ambient-pressure X-ray photoelectron spectroscopy (AP-XPS). Pt-Co alloy and separated Co particles co-existed in the bimetallic catalyst, whereas the former was determined as the dominant active structure with a Pt-Co-mixed-surface termination. During reaction, Pt and Co in the alloy structure nearly maintained their metallic state with slight oxygen decoration, yielding oxygen-metal site-pairs (O*-*). Combined kinetic investigations and DFT calculations reveal that the O*-modified catalytic surface of PtCo/CeO2 promotes CH bond activation with higher entropy contribution (less constraints) to compensate its higher activation barrier. Thermogravimetric analysis (TGA), transmission electron microscope (TEM) and Raman spectroscopy show that the PtCo/CeO2 catalyst is resistant to coke formation as effectively as Pt/CeO2 and can be easily regenerated by a mild CO2 treatment.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.035
      Issue No: Vol. 236 (2018)
       
  • Influence of surface-functionalized multi-walled carbon nanotubes on CdS
           nanohybrids for effective photocatalytic hydrogen production
    • Authors: Madhusudana Gopannagari; D. Praveen Kumar; Hanbit Park; Eun Hwa Kim; Palagiri Bhavani; D. Amaranatha Reddy; Tae Kyu Kim
      Pages: 294 - 303
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Madhusudana Gopannagari, D. Praveen Kumar, Hanbit Park, Eun Hwa Kim, Palagiri Bhavani, D. Amaranatha Reddy, Tae Kyu Kim
      Carbon nanotubes (CNTs) have enormous potential for application due to their extreme hydrophobicity. Further, their physico-chemical properties can be modified by surface functionalization. Acid functionalization of CNTs is one of the basic methodology for modification of their electro-chemical properties, resolving the poor dispersion capability, and improving the surface-active sites to enhance the photocatalytic efficiency. However, the role of surface functional groups on CNTs for water-splitting in association with CdS photocatalysts has not yet been sufficiently explored. Hence, in the present study, we report the influence of surface-functionalized CNT-metal nanoparticle (NP) hybrids attached to CdS nanorods for enhanced photocatalytic H2 production. Significant improvement in photocatalytic H2 production was observed for binary composites such as amine (Nf-), sulfonic (Sf-), and ascorbic acid (Af-) functionalized CNTs and CdS nanorods. Furthermore, the secondary functionalized Af-CNTs were incorporated with metal NPs and the photocatalytic activity was significantly improved in ternary metal-Af-CNT/CdS nanohybrids. Among the metal NPs, Pt- incorporated into Af-CNTs and its CdS nanohybrid led to the highest rate of H2 production (120.1 mmol h−1 g−1), corresponding to a 48-fold enhancement relative to that of pure CdS. The enhanced rate of H2 production is attributed to the influence of the surface functional groups on the CNTs. The intimate interfacial contact between CdS, functionalized CNTs and metal NPs leads to enhanced photocatalytic performance, as a contributing factor for improving photogenerated charge separation and transportation. Moreover, the functional groups on CNTs (Pt-Af-CNT/CdS) led to obvious advantages, such as enhanced photoactivity and photostability of CdS for H2 production. The photocatalytic performance of these nanohybrids was found to be highly influenced by the surface states of the CNTs, suggesting the importance of surface treatment of materials for H2 evolution.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.009
      Issue No: Vol. 236 (2018)
       
  • Bimetal MOF derived mesocrystal ZnCo2O4 on rGO with High performance in
           visible-light photocatalytic NO oxidization
    • Authors: Shuning Xiao; Donglai Pan; Rui Liang; Wenrui Dai; Qitao Zhang; Guoqiang Zhang; Chenliang Su; Hexing Li; Wei Chen
      Pages: 304 - 313
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Shuning Xiao, Donglai Pan, Rui Liang, Wenrui Dai, Qitao Zhang, Guoqiang Zhang, Chenliang Su, Hexing Li, Wei Chen
      A mesocrystal ZnCo2O4 on reduced graphene oxide (rGO) nano-composite was successfully synthesized by a low-temperature annealing of bimetal organic frameworks on rGO. In this nano-composite, rGO nanosheets worked as the two-dimensional support to significantly improve the dispersity and conductivity of nano-composites. The mesoporous ZnCo2O4 crystal derived from ZnCo-ZIF worked as the main active sites with the optimized Zn/Co ratio to ensure an ideal valence band structure as well as enhanced visible-light harvesting properties. The as-prepared rGO@ZnCo2O4 nano-composites showed a remarkable activity in visible-light photocatalytic NO oxidation with the conversion of 83.8% under visible light and 92.6% under simulated solar light. It also exhibited a higher stability than that of N-doped TiO2, thereby making this nano-composite as a promising and stable photocatalyst for environmental remediation.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.033
      Issue No: Vol. 236 (2018)
       
  • Exploration of surface properties of Sb-promoted copper vanadate catalysts
           for selective catalytic reduction of NOX by NH3
    • Authors: Jongsik Kim; Dong Wook Kwon; Somin Lee; Heon Phil Ha
      Pages: 314 - 325
      Abstract: Publication date: 15 November 2018
      Source:Applied Catalysis B: Environmental, Volume 236
      Author(s): Jongsik Kim, Dong Wook Kwon, Somin Lee, Heon Phil Ha
      A way to fulfill efficient exploitation of desired catalytic nature provided by V oxide is to modify its chemical structure through the incorporation of secondary transition metal species. This paper reports the use of Cu as a modifier of high-valent V oxide (V2O5) to produce a class of copper vanadates and their utilization as active sites for the selective catalytic reduction of NOX (X = 1 or 2) by NH3 (NH3-SCR). All catalysts contained ∼2 nm-sized copper vanadate particles highly dispersed on anatase with desired vanadate phases. The anatase-supported Cu5V2O10 provided a greater quantity of acid sites with improved redox character than Cu1V2O6, Cu2V2O7, and Cu3V2O8, thereby exhibiting the greatest NH3-SCR performance under ideal reaction conditions. Anatase-supported Cu3V2O8, however, was found to possess the most preferred surface properties among the catalysts post sulfation. This was evidenced by NH3-SCR runs of the catalysts under reaction conditions with H2O and SO2-including stream, where all catalysts were pre-sulfated by SO2 and O2 at elevated temperatures. The NH3-SCR performance of the optimum Cu3V2O8 on anatase was further promoted after sulfation of the catalyst with the optimum content of Sb promoter. The Sb promoter was verified to enhance the redox feature and minimize the interactions among catalyst surfaces and SO2/ammonium (bi)sulfates during the NH3-SCR, as evidenced by durability experiments. While showing N2 selectivities as ∼100% at ≤ 400 °C, the optimized Sb-promoted Cu3V2O8 on anatase showed high NOX conversions (≥ ∼85%) at ≥ 220 °C and outperformed the control vanadia-tungstate on anatase, which was used to simulate a commercial catalyst. This paper remarks the exploration of the variable structures of metal vanadates can be a good strategy to discover high-performance catalytic solids for the reduction of NOX species.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
      DOI: 10.1016/j.apcatb.2018.05.024
      Issue No: Vol. 236 (2018)
       
  • Positioning cyanamide defects in g-C3N4: Engineering energy levels and
           active sites for superior photocatalytic hydrogen evolution
    • Authors: Jili Yuan; Xia Liu Yanhong Tang Yunxiong Zeng Longlu Wang
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Jili Yuan, Xia Liu, Yanhong Tang, Yunxiong Zeng, Longlu Wang, Shuqu Zhang, Tao Cai, Yutang Liu, Shenglian Luo, Yong Pei, Chengbin Liu
      g-C3N4 has recently emerged as a promising photocatalyst for solar energy conversion. Nonetheless, attempts to enhance its inherently low activity are rarely based on precise molecular tunability strategy. In this study, two-type cyanamide defects-grafting g-C3N4 (CCN) was prepared through the thermal polymerization of thiourea in the presence of KCl. Stable potassium isothiocyanate (KSCN) was in situ generated via thiourea isomerization and then reacted with different amino groups (NH2 and NH) in tri-s-triazine rings to obtain two-type cyanamide defects. Theoretical calculations and experiment results confirm that the ratio of the two-type cyanamide defects could be adjusted by KCl dosage, accompanying tunable energy levels of CCN. The charge carrier transfer and separation of CCN was greatly improved. Furthermore, the existence of cyanamide defects hindered the formation of intermolecular hydrogen bonds among g-C3N4, which facilitated the formation of porous structure and exposed more active sites for photocatalytic hydrogen evolution reaction (HER). As a result, the optimized photocatalyst (CCN-0.03) showed a high HER rate of 4.0 mmol g−1h−1, which was 5 times higher than 0.8 mmol g−1h−1 for pristine g-C3N4. And the apparent quantum efficiency reached up to 14.65% at 420 ± 10 nm. The findings deepen the understanding on precise molecular tuning of g-C3N4.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
       
  • N-Annulated perylene-based organic dyes sensitized graphitic carbon
           nitride to form an amide bond for efficient photocatalytic hydrogen
           production under visible-light irradiation
    • Authors: Fengtao Zhiqiang; Wang Shicong Zhang Kang Yun Haonan Xueqing Gong
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Fengtao Yu, Zhiqiang Wang, Shicong Zhang, Kang Yun, Haonan Ye, Xueqing Gong, Jianli Hua, He Tian
      In this work, two new N-annulated perylene-based organic sensitizers (PY-1 and PY-2) have been developed for dye-sensitized graphitic carbon nitride (g-C3N4) to remarkably enhance photocatalytic hydrogen production under visible-light irradiation (420 nm ≤ λ ≤ 780 nm). The results showed that the H2 production rates of the PY-1/g-C3N4/Pt and PY-2/g-C3N4/Pt were up to 5508.1 μmol h−1 g−1 and 11,855.4 μmol h−1 g−1, respectively, which were 8.98 and 19.3 times higher than that of the g-C3N4/Pt, respectively. Specifically, an impressive record apparent quantum efficiency (AQY) of 27.16% for PY-2/g-C3N4/Pt system was achieved at λ = 550 nm monochromatic light irradiation. Moreover, the formation of amide bonds between dye molecules and g-C3N4 was firstly confirmed by FTIR spectrum and theoretical calculation. The amide bonds provided the electron transfer channels to significantly improve interface charge transfer and separation, thus resulting in a more efficient hydrogen production. More importantly, PY-1/g-C3N4/Pt and PY-2/g-C3N4/Pt displayed good stability under long-term irradiation and was favorable and significant for practical application. Our work indicated that dye sensitized g-C3N4 to form an amide bond is a promising strategy to realize the effective conversion of solar energy to hydrogen energy through molecular engineering.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
       
  • Ti3C2Tx MXene as a Janus cocatalyst for concurrent promoted photoactivity
           and inhibited photocorrosion
    • Authors: Xiuqiang Xie; Nan Zhang Zi-Rong Tang Masakazu Anpo Yi-Jun
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Xiuqiang Xie, Nan Zhang, Zi-Rong Tang, Masakazu Anpo, Yi-Jun Xu
      Employing a single cocatalyst to concurrently mediate reactions with electrons and those with holes toward efficient and stable photocatalysts is highly desirable yet challenging. Herein, two-dimensional (2D) in-plane CdS/Ti3C2Tx sheet-onto-sheet heterostructures have been deliberately constructed, in which Ti3C2Tx, a prototype MXene, is demonstrated to act as a Janus cocatalyst for simultaneously promoting electron-driven photoreduction reaction and inhibiting hole-induced photocorrosion of semiconductor CdS. Ti3C2Tx serves as an electron mediator to boost the electron extraction from CdS for photoreduction reactions. The interlayer assembly maintains the accessible surface reaction sites of CdS, while concomitantly the Cd2+ confinement effect of Ti3C2Tx retards the oxidative holes induced photocorrosion of CdS through preventing Cd2+ leaching. As a result, the photoactivity and stability of CdS are concurrently enhanced through coupling with Ti3C2Tx as a Janus cocatalyst. This facile and double-gain strategy is expected to present a conceptual approach to the rational design of efficient and stable photocatalysts toward solar energy conversion.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
       
  • A high-performance Bi2O3/Bi2SiO5 p-n heterojunction photocatalyst induced
           by phase transition of Bi2O3
    • Authors: Haojie Qiang; Hao Tong Chen Linghua Zhang Daimei Chen Chao
      Abstract: Publication date: 5 December 2018
      Source:Applied Catalysis B: Environmental, Volume 237
      Author(s): Haojie Lu, Qiang Hao, Tong Chen, Linghua Zhang, Daimei Chen, Chao Ma, Wenqing Yao, Yongfa Zhu
      In this work, Bi2O3/Bi2SiO5 p-n heterojunction photocatalyst was successfully fabricated via a facile one-step synthesis using Bi(NO3)3 and nano-SiO2 as precursors. With the increasing amount of SiO2, α-Bi2O3 gradually transferred into β-Bi2O3, and Bi2O3/Bi2SiO5 p-n heterojunction was obtained at the same time. The as-prepared samples were systematically characterized by XRD, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (DRS). The Bi2O3/Bi2SiO5 heterojunction photocatalysts exhibited higher photocatalytic activity than α-Bi2O3 on the degradation of organic pollutants under simulated sunlight irradiation. The enhanced photocatalytic activity could be ascribed to the larger specific surface area, the larger contact angle, the formation of β-Bi2O3 and construction of p-n heterojunction. More importantly, the phase transition mechanism of Bi2O3 in Bi2O3/Bi2SiO5 heterojunction photocatalyst was proposed, which is significant for the theoretical study and application of photocatalytic materials.
      Graphical abstract image

      PubDate: 2018-06-01T06:07:47Z
       
 
 
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