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  Subjects -> ENGINEERING (Total: 2417 journals)
    - CHEMICAL ENGINEERING (207 journals)
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    - ELECTRICAL ENGINEERING (111 journals)
    - ENGINEERING (1267 journals)
    - ENGINEERING MECHANICS AND MATERIALS (400 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
Chinese Journal of Catalysis
Journal Prestige (SJR): 0.833
Citation Impact (citeScore): 3
Number of Followers: 2  
 
  Full-text available via subscription Subscription journal
ISSN (Print) 1872-2067
Published by Elsevier Homepage  [3163 journals]
  • Recent advances on controllable and selective catalytic oxidation of
           cyclohexene
    • Authors: Hongen Cao; Boran Zhu; Yufan Yang; Lin Xu; Lei Yu; Qing Xu
      Pages: 899 - 907
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Hongen Cao, Boran Zhu, Yufan Yang, Lin Xu, Lei Yu, Qing Xu
      Because of multiple potential reaction sites and variable oxidation depths, oxidation of cyclohexene can lead to a mixture of products with different oxidation states and functional groups, such as 7-oxabicyclo[4.1.0]heptane, trans/cis-cyclohexane-1,2-diol, cyclohex-2-en-1-ol, cyclohex-2-en-1-one, and even adipic acid. These products are broadly and abundantly used intermediates in the chemical industry; therefore, controllable oxidation reactions for cyclohexene that can selectively afford the targeted products are synthetically valuable for applications in both the academy and industry, thus becoming the aim of synthetic and catalytic chemists in the field. Many reports on selective oxidation of cyclohexene have recently appeared in the literature because of its significance. This short review summarizes the recent advances on this subject, and the contents are mainly classified based on the chosen oxidants. We hope that this review can provide a useful guide for controllable and selective catalytic oxidation of cyclohexene for interested readers from both the academy and industry.
      Graphical abstract image

      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63050-5
       
  • A viewpoint on catalytic origin of boron nitride in oxidative
           dehydrogenation of light alkanes
    • Authors: Lei Shi; Dongqi Wang; An-Hui Lu
      Pages: 908 - 913
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Lei Shi, Dongqi Wang, An-Hui Lu
      Oxidative dehydrogenation of light alkanes to alkenes is an attractive alternative route for industrial direct dehydrogenation because of favorable thermodynamic and kinetic characteristics, but encounters difficulties in selectivity control for alkenes because of over-oxidation reactions that produce a substantial amount of undesired carbon oxides. Recent progress has revealed that boron nitride is a highly promising catalyst in the oxidative dehydrogenation of light alkanes because of its superior selectivity for and high productivity of light alkenes, negligible formation of CO2, and remarkable catalyst stability. From this viewpoint, recent works on boron nitride in the oxidative dehydrogenations of ethane, propane, butane, and ethylbenzene are reviewed, and the emphasis of this viewpoint is placed on discussing the catalytic origin of boron nitride in oxidative dehydrogenation reactions. After analyzing recent progress in the use of boron nitride for oxidative dehydrogenation reactions and finding much new evidence, we conclude that pure boron nitride is catalytically inert, and an activation period is required under the reaction conditions; this process is accompanied by an oxygen functionalization at the edge of boron nitride; the B-O species themselves have no catalytic activity in C-H cleavage, and the B-OH groups, with the assistance of molecular oxygen, play the key role in triggering the oxidative dehydrogenation of propane; the dissociative adsorption of molecular oxygen is involved in the reaction process; and a straightforward strategy for preparing an active boron nitride catalyst with hydroxyl groups at the edges can efficiently enhance the catalytic efficacy. A new redox reaction cycle based on the B-OH sites is also proposed. Furthermore, as this is a novel catalytic system, there is an urgent need to develop new methods to optimize the catalytic performances, clarify the catalytic function of boron species in the alkane ODH reactions, and disclose the reaction mechanism under realistic reaction conditions.
      Graphical abstract image

      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63060-8
       
  • A highly efficient flower-like cobalt catalyst for electroreduction of
           carbon dioxide
    • Authors: Gang Yang; Zhipeng Yu; Jie Zhang; Zhenxing Liang
      Pages: 914 - 919
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Gang Yang, Zhipeng Yu, Jie Zhang, Zhenxing Liang
      Electrochemical conversion of CO2 into fuel has been regarded as a promising approach to achieve the global carbon cycle. Herein, we report an efficient cobalt catalyst with a unique flower-like morphology synthesized by a green and facile hydrothermal method, in which n-butylamine is used as the capping agent. The resultant catalyst shows superior electrocatalytic activity toward CO2 electroreduction, which is highly selective for generating formate with a Faraday efficiency of 63.4%. Electrochemical analysis reveals that the oxide on the surface is essential for the electrocatalysis of the CO2 reduction reaction. Cyclic voltammograms further suggest that this catalyst is highly active for the oxidation of reduced product, and can thus be seen as a bifunctional catalyst.
      Graphical abstract image

      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63021-9
       
  • Fe-TiO2 and Fe2O3 quantum dots co-loaded on MCM-41 for removing aqueous
           rose bengal by combined adsorption/photocatalysis
    • Authors: Guoqiang Shen; Lun Pan; Zhe Lü; Chongqing Wang; Fazal-e- Aleem; Xiangwen Zhang; Ji-Jun Zou
      Pages: 920 - 928
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Guoqiang Shen, Lun Pan, Zhe Lü, Chongqing Wang, Fazal-e- Aleem, Xiangwen Zhang, Ji-Jun Zou
      Adsorption and photodegradation are promising approaches for removing organic pollutions. In this study, we combined these two processes by co-loading Fe-TiO2 and Fe2O3 quantum dots (QDs) on porous MCM-41, using a simple hydrolysis method. X-ray diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy results indicated that Fe-TiO2 QDs are formed at low Fe precursor concentrations, while additional Fe2O3 QDs are formed at higher Fe precursor concentrations. The Fe2O3 and Fe-TiO2 QDs impart high adsorption capacity and high photoactivity to the porous MCM-41, respectively. Thus, their combination results in a synergic effect of the adsorption and photodegradation. The highest-performing sample exhibits excellent performance in removing rose bengal from aqueous solution.
      Graphical abstract image

      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)62976-0
       
  • Effective removal of the protective ligands from Au nanoclusters by
           ambient pressure nonthermal plasma treatment for CO oxidation
    • Authors: Yuan Tan; Hua Liu; Xiao Yan Liu; Aiqin Wang; Changjun Liu; Tao Zhang
      Pages: 929 - 936
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Yuan Tan, Hua Liu, Xiao Yan Liu, Aiqin Wang, Changjun Liu, Tao Zhang
      We used a dielectric barrier discharge (DBD) plasma technique to eliminate the protective ligand of ZnAl-hydrotalcite-supported gold nanoclusters. We used X-ray powder diffraction, ultraviolet-visible spectrophotometry, thermogravimetric analysis, and high angle annular dark-field-scanning transmission electron microscopy characterization to show that the samples pretreated with/without DBD-plasma displayed different performances in CO oxidation. The enhanced activity was obtained on the plasma-treated samples, implying that the protective ligand was effectively removed via the plasma technique. The crystal structure of the plasma-treated samples changed markedly, suggesting that the plasma treatment could not only break the chemical bond between the gold and the protective agent but could also decompose the interlayer ions over the hydrotalcite support. The particle sizes of the gold after DBD-plasma treatment implied that it was a good way to control the size of the gold nanoparticles under mild conditions.
      Graphical abstract image

      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63018-9
       
  • Cloning, overexpression, and characterization of a novel organic
           solvent-tolerant lipase from Paenibacillus pasadenensis CS0611
    • Authors: Jiaxin Gao; Xiaoyang Ou; Pei Xu; Minhua Zong; Wenyong Lou
      Pages: 937 - 945
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Jiaxin Gao, Xiaoyang Ou, Pei Xu, Minhua Zong, Wenyong Lou
      We found a novel lipase gene in the Paenibacillus pasadenensis CS0611 strain. The lipase gene sequence was cloned into the pET-28a expression vector to construct a recombinant lipase protein containing 6 × His tags at the C- and N-termini, respectively. High-level expression of the lipase in E.coli BL21 (DE3) was obtained upon induction with IPTG at 20 °C. The recombinant lipase activity was approximately 1631-fold higher than the wild type. His-tagged recombinant lipase was purified rapidly and efficiently by using Ni-charged affinity chromatography with 63.5% recovery and a purification factor of 10.78. The purified lipase was stable in a broad range of temperatures and pH values, with the optimal temperature and pH being 50 °C and 7.0, respectively. Its activity was stimulated to different degrees in the presence of metal ions such as Ca2+, Mg2+, and some non-ionic surfactants. In addition, the purified lipase was activated by a series of water-miscible organic solvents such as some short carbon chain alcohols and was highly tolerant to some water-immiscible organic solvents.
      Graphical abstract image

      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63033-5
       
  • The role of graphene coating on cordierite-supported Pd monolithic
           catalysts for low-temperature combustion of toluene
    • Authors: Wen Li; Hongqi Ye; Gonggang Liu; Hongchao Ji; Yonghua Zhou; Kai Han
      Pages: 946 - 954
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Wen Li, Hongqi Ye, Gonggang Liu, Hongchao Ji, Yonghua Zhou, Kai Han
      In the present work, a Pd/graphene/cordierite (Pd/Gr/Cor) composite was prepared as a monolithic catalyst for low-temperature combustion of toluene. We mainly focused on understanding the role of graphene coating through investigation of catalytic performance and adsorption behavior of the composite. Compared with the traditional Pd/Cor catalyst without graphene coating, Pd/Gr/Cor catalyst delivered much higher activity and stability for toluene catalytic combustion in both dry and moist conditions. Transmission electron microscopy (TEM) and hydrophobic characterizations indicated that graphene coating can considerably improve the dispersity of Pd nanoparticles and enhance the hydrophobicity of the cordierite support. The adsorption behavior of the above two catalysts, including adsorption isothermal, adsorption kinetics, and adsorption thermodynamics were carefully investigated. The simulation results indicated that a large amount of toluene was adsorbed on graphene surface through relatively weak interaction, whereas only a relatively small amount of toluene was adsorbed on Pd surface with strong affinity. The adsorption thermal calculation indicated that the adsorption of toluene on graphene was a process with reduced entropy, indicating highly-ordered assembly of toluene molecular on graphene. It is the significant concentration and affinity gap between graphene and Pd that ensures a simultaneously and rapid transfer of toluene during the reaction process.
      Graphical abstract image

      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63015-3
       
  • Enhancement of catalytic activity by homo-dispersing S2O82–-Fe2O3
           nanoparticles on SBA-15 through ultrasonic adsorption
    • Authors: Qingyan Chu; Jing Chen; Wenhua Hou; Haoxuan Yu; Ping Wang; Rui Liu; Guangliang Song; Hongjun Zhu; Pingping Zhao
      Pages: 955 - 963
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Qingyan Chu, Jing Chen, Wenhua Hou, Haoxuan Yu, Ping Wang, Rui Liu, Guangliang Song, Hongjun Zhu, Pingping Zhao
      Mesoporous superacids S2O8 2–-Fe2O3/SBA-15 (SFS) with active nanoparticles are prepared by ultrasonic adsorption method. This method is adopted to ensure a homo-dispersed nanoparticle active phase, large specific surface area and many acidic sites. Compared with bulk S2O8 2–-Fe2O3, Brönsted acid catalysts and other reported catalysts, SFS with an Fe2O3 loading of 30% (SFS-30) exhibits an outstanding activity in the probe reaction of alcoholysis of styrene oxide by methanol with 100% yield. Moreover, SFS-30 also shows a more excellent catalytic performance than bulk S2O8 2–-Fe2O3 towards the alcoholysis of other ROHs (R = C2H5-C4H9). Lewis and Brönsted acid sites on the SFS-30 surfaces are confirmed by pyridine adsorbed infrared spectra. The highly efficient catalytic activity of SFS-30 may be attributed to the synergistic effect from the nano-effect of S2O8 2–-Fe2O3 nanoparticles and the mesostructure of SBA-15. Finally, SFS-30 shows a good catalytic reusability, providing an 84.1% yield after seven catalytic cycles.
      Graphical abstract image

      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)63007-9
       
  • Green and efficient epoxidation of methyl oleate over hierarchical TS-1
    • Authors: Yue Wei; Gang Li; Qiang Lü; Chuanying Cheng; Hongchen Guo
      Pages: 964 - 972
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Yue Wei, Gang Li, Qiang Lü, Chuanying Cheng, Hongchen Guo
      The epoxidation of methyl oleate (MO) was conducted in the presence of aqueous H2O2 as the oxidant and hierarchical TS-1 (HTS-1) as the catalyst; the catalyst was synthesized using polyquaternium-6 as the mesopore template. The effects of various parameters, i.e., H2O2/C=C molar ratio, oxidant concentration, amount of the catalyst, reaction temperature, and time, were systematically studied. Furthermore, response surface methodology (RSM) was used to optimize the conditions to maximize the yield of epoxy MO and to evaluate the significance and interplay of the factors affecting the epoxy MO production. The H2O2/C=C molar ratio and catalyst amount were the determining factors for MO epoxidation, wherein the maximum yield of epoxy MO reached 94.9% over HTS-1 under the optimal conditions.
      Graphical abstract image

      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63014-1
       
  • Enhancing the photocatalytic activity and photostability of zinc oxide
           nanorod arrays via graphitic carbon mediation
    • Authors: Xuewei Zhang; Xueliang Zhang; Xin Wang; Lequan Liu; Jinhua Ye; Defa Wang
      Pages: 973 - 981
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Xuewei Zhang, Xueliang Zhang, Xin Wang, Lequan Liu, Jinhua Ye, Defa Wang
      Low optical absorption and photocorrosion are two crucial issues limiting the practical applications of zinc oxide (ZnO)-based photocatalysts. In this paper, we report the fabrication of graphitic-carbon-mediated ZnO nanorod arrays (NRAs) with enhanced photocatalytic activity and photostability for CO2 reduction under visible light irradiation. ZnO NRA/C-x (x = 005, 01, 02, and 03) nanohybrids are prepared by calcining pre-synthesized ZnO NRAs with different amounts of glucose (0.05, 0.1, 0.2, and 0.3 g) as a carbon source via a hydrothermal method. X-ray photoelectron spectroscopy reveals that the obtained ZnO NRA/C-x nanohybrids are imparted with the effects of both carbon doping and carbon coating, as evidenced by the detected C−O−Zn bond and the C−C, C−O and C=O bonds, respectively. While the basic structure of ZnO remains unchanged, the UV-Vis absorption spectra show increased absorbance owing to the carbon doping effect in the ZnO NRA/C-x nanohybrids. The photoluminescence (PL) intensities of ZnO NRA/C-x nanohybrids are lower than that of bare ZnO NRA, indicating that the graphitic carbon layer coated on the surface of the ZnO NRA significantly enhances the charge carrier separation and transport, which in turn enhances the photoelectrochemical property and photocatalytic activity of the ZnO NRA/C-x nanohybrids for CO2 reduction. More importantly, a long-term reaction of photocatalytic CO2 reduction demonstrates that the photostability of ZnO NRA/C-x nanohybrids is significantly increased in comparison with the bare ZnO NRA.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63010-4
       
  • CoNiP/NC polyhedrons derived from cobalt-based zeolitic imidazolate
           frameworks as an active electrocatalyst for oxygen evolution
    • Authors: Jintang Li; Guiqing Du; Xian Cheng; Pingjing Feng; Xuetao Luo
      Pages: 982 - 987
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Jintang Li, Guiqing Du, Xian Cheng, Pingjing Feng, Xuetao Luo
      The oxygen evolution reaction (OER) plays an important role in the development of energy conversation and storage technologies including water splitting and metal-air batteries, where the development of electrocatalysts is paramount. In this study, cobalt-nickel phosphide/N-doped porous carbon polyhedron electrocatalysts (CoNiP/NC) were prepared by a facile two-step carbonization method and subsequent phosphorization calcination in an Ar atmosphere using cobalt-based zeolitic imidazolate frameworks (ZIFs) as precursors. Among the electrocatalysts obtained by controlling the carbonization and phosphorization temperature, the CoNiP/NC700 catalyst, where 700 refers to the calcination temperature (°C), exhibited superior electrocatalytic activity for the OER with an onset overpotential of approximate 220 mV and an overpotential of approximate 300 mV in alkaline solution at a current density of 10 mA/cm2. The CoNi/NC and Co/NC Samples were also tested for comparison and CoNiP/NC exhibited the better electrocatalytic activity at all the temperatures tested. The superior electrocatalytic activity of the phosphorization hybrid material can be attributed to the superior synergistic effect of Co, Ni, P and C due to their strong electron coupling interactions. The interconnected amorphous carbon anchored the active Co compounds to avoid aggregation and maintained conducting channels for electron transfer. The composite electrocatalyst prepared herein is a promising candidate for use in electrocatalytic OERs.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63030-x
       
  • Layered double hydroxide-like Mg3Al1−xFex materials as supports for Ir
           catalysts: Promotional effects of Fe doping in selective hydrogenation of
           cinnamaldehyde
    • Authors: Weiwei Lin; Haiyang Cheng; Xiaoru Li; Chao Zhang; Fengyu Zhao; Masahiko Arai
      Pages: 988 - 996
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Weiwei Lin, Haiyang Cheng, Xiaoru Li, Chao Zhang, Fengyu Zhao, Masahiko Arai
      Supported Ir catalysts were prepared using layered double hydrotalcite-like materials, such as Mg3Al1−x Fe x , containing Fe and Al species in varying amounts as supports. These Ir catalysts were applied for the selective hydrogenation of cinnamaldehyde (CAL). When x was changed from 0 (Ir/Mg3Al) to 1 (Ir/Mg3Fe), the rate of CAL hydrogenation reached a maximum at approximately x = 0.25, while the selectivity to unsaturated alcohol, i.e., cinnamyl alcohol, monotonously increased from 44.9% to 80.3%. Meanwhile, the size of the supported Ir particles did not change significantly with x, remaining at 1.7 ± 0.2 nm, as determined by transmission electron microscopy. The chemical state of Ir and Fe species in the Ir/Mg3Al1−x Fe x catalysts was examined by temperature programmed reduction by H2 and X-ray photoelectron spectroscopy. The surface of the supported Ir particles was also examined through the in-situ diffuse reflectance infrared Fourier-transform of a probe molecule of CO. On the basis of these characterization results, the effects of Fe doping to Mg3Al on the structural and catalytic properties of Ir particles in selective CAL hydrogenation were discussed. The significant factors are the electron transfer from Fe2+ in the Mg3Al1–x Fe x support to the dispersed Ir particles and the surface geometry.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63042-6
       
  • Chiral basket-handle porphyrin-Co complexes for the catalyzed asymmetric
           cycloaddition of CO2 to epoxides
    • Authors: Xiying Fu; Xinyao Jing; Lili Jin; Lilong Zhang; Xiaofeng Zhang; Bin Hu; Huanwang Jing
      Pages: 997 - 1003
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Xiying Fu, Xinyao Jing, Lili Jin, Lilong Zhang, Xiaofeng Zhang, Bin Hu, Huanwang Jing
      The catalytic synthesis of cyclic carbonates via the cycloaddition of CO2 to epoxides is a standard methodology for CO2 fixation. For this purpose, chiral basket-handle porphyrin-Co complexes were devised, prepared, and fully characterized by nuclear magnetic resonance, mass spectrometry, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, and specific rotation. The proposed metalloporphyrin catalysts were synthesized with either 1,1′-bi-2-naphthol or L-phenylalanine, which have different chirality, and then applied to the coupling of propylene oxide and CO2 for generating chiral cyclic carbonates with good enantioselectivity under extremely mild conditions in the presence of tetrabutyl ammonium chloride as a co-catalyst. The good enantioselectivity in the cycloaddition reaction is attributed to a synergistic interplay between the chiral porphyrin catalysts and the substrate. The mechanism and enantioselectivity of the asymmetric cycloaddition reaction is discussed.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63023-2
       
  • Bimetallic Cr-In/H-SSZ-13 for selective catalytic reduction of nitric
           oxide by methane
    • Authors: Jun Yang; Yupeng Chang; Weili Dai; Guangjun Wu; Naijia Guan; Landong Li
      Pages: 1004 - 1011
      Abstract: Publication date: May 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 5
      Author(s): Jun Yang, Yupeng Chang, Weili Dai, Guangjun Wu, Naijia Guan, Landong Li
      Bimetallic Cr-In/H-SSZ-13 zeolites were prepared by wet impregnation and investigated for selective catalytic reduction of nitric oxide by methane (CH4-SCR). Reduction-oxidation treatments led to close contact and interaction between Cr and In species in these zeolites, as revealed by transmission electron microscopy and X-ray photoelectron spectroscopy. Compared to monometallic Cr/H-SSZ-13 and In/H-SSZ-13, the bimetallic catalyst system exhibited dramatically enhanced CH4-SCR performance, i.e., NO conversion greater than 90% and N2 selectivity greater than 99% at 550 °C in the presence of 6% H2O under a high gas hourly space velocity of 75 000/h. The bimetallic Cr-In/H-SSZ-13 showed very good stability in CH4-SCR with no significant activity loss for over 160 h. Catalytic data revealed that CH4 and NO were activated on the In and Cr sites of Cr-In/H-SSZ-13, respectively, both in the presence of O2 during CH4-SCR.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63054-2
       
  • Preface to Special Issue on Environmental and Energy Catalysis
    • Authors: Fan Dong; Jiguang Deng
      First page: 565
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Fan Dong, Jiguang Deng
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63062-1
       
  • Copper-based non-precious metal heterogeneous catalysts for environmental
           remediation
    • Authors: Yarong Fang; Yanbing Guo
      Pages: 566 - 582
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Yarong Fang, Yanbing Guo
      This paper presents a detailed review of copper-based catalysts used in wide-ranging environmental remediation, including gas, liquid and solid phase pollutant elimination. Latest advances in the remarkable catalytic activity of copper-based catalysts, including bulk CuO x , supported CuO x , and solid solution CuO x -X are emphasized. The structure-activity relationships among the crystal structure, morphology, catalyst support, and catalytic performance in specific catalytic reactions for environmental remediation are discussed. Furthermore, current obstacles faced by Cu-based catalysts and potential strategies to address them have been proposed, which may aid the future research and development of highly efficient Cu-based non-precious metal catalysts.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)62996-6
       
  • Enhancing oxygen reduction electrocatalysis through tuning crystal
           structure: Influence of intermetallic MPt nanocrystals
    • Authors: Jiashun Liang; Zhengpei Miao; Feng Ma; Ran Pan; Xian Chen; Tanyuan Wang; Huan Xie; Qing Li
      Pages: 583 - 589
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Jiashun Liang, Zhengpei Miao, Feng Ma, Ran Pan, Xian Chen, Tanyuan Wang, Huan Xie, Qing Li
      The slow kinetics of oxygen reduction reaction (ORR) occurring at the cathode of a proton exchange membrane fuel cell require the presence of an electrocatalyst to reduce overpotential. MPt alloy nanocrystals (NCs) have been investigated over the last decade as efficient catalysts for ORR and recent studies have shown that structurally-ordered MPt NCs, i.e., intermetallic NCs (iNCs), are more active and exhibit enhanced stability compared with the corresponding randomly alloyed analogues. This mini-review highlights the recent progress in iNC catalyst development for ORR with emphasis on correlating the synthesis-structure-activity relationship. Perspectives and possible research directions to enhance MPt iNC catalytic performance are also proposed.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)62989-9
       
  • I-III-VI chalcogenide semiconductor nanocrystals: Synthesis, properties,
           and applications
    • Authors: Shiqi Li; Xiaosheng Tang; Zhigang Zang; Yao Yao; Zhiqiang Yao; Haizheng Zhong; Bingkun Chen
      Pages: 590 - 605
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Shiqi Li, Xiaosheng Tang, Zhigang Zang, Yao Yao, Zhiqiang Yao, Haizheng Zhong, Bingkun Chen
      Colloidal semiconductor nanocrystals have been proven to be promising candidates for applications in low-cost and high-performance photovoltaics, bioimaging, and photocatalysis due to their novel size- and shape-dependent properties. Among the colloidal systems, I-III-VI semiconductor nanocrystals (NCs) have drawn much attention in the past few decades. Compared to binary NCs, ternary I-III-VI NCs not only exhibit low toxicity, but also a high performance similar to that of binary NCs. In this review, we mainly focus on the synthesis, properties, and applications of I-III-VI NCs. We summarize the major synthesis methods, analyze their photophysical and electronic properties, and highlight some of the latest applications of I-III-VI NCs in solar cells, light-emitting diodes, bioimaging, and photocatalysis. Finally, based on the information reviewed, we highlight the existing problems and challenges.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63052-9
       
  • Fabrication of ultrafine Pd nanoparticles on 3D ordered macroporous TiO2
           for enhanced catalytic activity during diesel soot combustion
    • Authors: Yuechang Wei; Qiangqiang Wu; Jing Xiong; Jian Liu; Zhen Zhao
      Pages: 606 - 612
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Yuechang Wei, Qiangqiang Wu, Jing Xiong, Jian Liu, Zhen Zhao
      Nanocatalysts consisting of three-dimensionally ordered macroporous (3DOM) TiO2-supported ultrafine Pd nanoparticles (Pd/3DOM-TiO2-GBMR) were readily fabricated by gas bubbling-assisted membrane reduction (GBMR) method. These catalysts had a well-defined and highly ordered macroporous nanostructure with an average pore size of 280 nm. In addition, ultrafine hemispherical Pd nanoparticles (NPs) with a mean particle size of 1.1 nm were found to be well dispersed over the surface of the 3DOM-TiO2 support and deposited on the inner walls of the material. The nanostructure of the 3DOM-TiO2 support ensured efficient contact between soot particles and the catalyst. The large interface area between the ultrafine Pd NPs and the TiO2 also increased the density of sites for O2 activation as a result of the strong metal (Pd)-support (TiO2) interaction (SMSI). A Pd/3DOM-TiO2-GBMR catalyst with ultrafine Pd NPs (1.1 nm) exhibited higher catalytic activity during diesel soot combustion compared with that obtained from a specimen having relatively large Pd NPs (5.0 nm). The T 10, T 50 and T 90 values obtained from the former were 295, 370 and 415 °C. Both the activity and nanostructure of the Pd/3DOM-TiO2-GBMR catalyst were stable over five replicate soot oxidation trials. These results suggest that nanocatalysts having a 3DOM structure together with ultrafine Pd NPs can decrease the amount of Pd required, and that this approach has potential practical applications in the catalytic combustion of diesel soot particles.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)62939-5
       
  • NiFe layered double-hydroxide nanoparticles for efficiently enhancing
           performance of BiVO4 photoanode in photoelectrochemical water splitting
    • Authors: Qizhao Wang; Tengjiao Niu; Lei Wang; Jingwei Huang; Houde She
      Pages: 613 - 618
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Qizhao Wang, Tengjiao Niu, Lei Wang, Jingwei Huang, Houde She
      A bismuth vanadate (BiVO4) photoanode with a cocatalyst consisting of NiFe layered double-hydroxide (NiFe-LDH) nanoparticles was fabricated for photoelectrochemical (PEC) water splitting. NiFe-LDH nanoparticles, which can improve light-absorption capacities and facilitate efficient hole transfer to the surface, were deposited on the surface of the BiVO4 photoanode by a hydrothermal method. All the samples were characterized using X-ray diffraction, scanning electron microscopy, and diffuse-reflectance spectroscopy. Linear sweep voltammetry and current-time plots were used to investigate the PEC activity. The photocurrent response of NiFe-LDH/BiVO4 at 1.23 V vs the reversible hydrogen electrode was higher than those of Ni(OH)2/BiVO4, Fe(OH)2/BiVO4 and pure BiVO4 electrodes under visible-light illumination. NiFe-LDH/BiVO4 also gave a superior PEC hydrogen evolution performance. Furthermore, the stability of the NiFe-LDH/BiVO4 photoanode was excellent compared with that of the bare BiVO4 photoanode, and offers a novel method for solar-assisted water splitting.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)62987-5
       
  • Synergistic photo-thermal catalytic NO purification of MnOx/g-C3N4:
           Enhanced performance and reaction mechanism
    • Authors: Peng Chen; Fan Dong; Maoxi Ran; Jiarui Li
      Pages: 619 - 629
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Peng Chen, Fan Dong, Maoxi Ran, Jiarui Li
      Both MnO x and g-C3N4 have been proved to be active in the catalytic oxidation of NO, and their individual mechanisms for catalytic NO conversion have also been investigated. However, the mechanism of photo-thermal catalysis of the MnO x /g-C3N4 composite remains unresolved. In this paper, MnO x /g-C3N4 catalysts with different molar ratios were synthesized by the precipitation approach at room temperature. The as-prepared catalysts exhibit excellent synergistic photo-thermal catalytic performance towards the purification of NO in air. The MnO x /g-C3N4 catalysts contain MnO x with different valence states on the surface of g-C3N4. The thermal catalytic reaction for NO oxidation on MnO x and the photo-thermal catalytic reaction on 1:5 MnO x /g-C3N4 were investigated by in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS). The results show that light exerted a weak effect on NO oxidation over MnO x , and it exerted a positive synergistic effect on NO conversion over 1:5 MnO x /g-C3N4. A synergistic photo-thermal catalytic cycle of NO oxidation on MnO x /g-C3N4 is proposed. Specifically, photo-generated electrons (e−) are transferred to MnO x and participate in the synergistic photo-thermal reduction cycle (Mn4+ →Mn3+ →Mn2+). The reverse cycle (Mn2+ →Mn3+ →Mn4+) can regenerate the active oxygen vacancy sites and inject electrons into the g-C3N4 hole (h + ). The active oxygen (O−) was generated in the redox cycles among manganese species (Mn4+/Mn3+/Mn2+) and could oxidize the intermediates (NOH and N2O2 −) to final products (NO2 − and NO3 −). This paper can provide insightful guidance for the development of better catalysts for NO x purification.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63029-3
       
  • Effect of pore size in mesoporous MnO2 prepared by KIT-6 aged at different
           temperatures on ethanol catalytic oxidation
    • Authors: Bingyang Bai; Qi Qiao; Yanping Li; Yue Peng; Junhua Li
      Pages: 630 - 638
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Bingyang Bai, Qi Qiao, Yanping Li, Yue Peng, Junhua Li
      KIT-6 mesoporous silica aged at 40, 100, and 150 °C were used as hard templates to prepare different mesoporous MnO2 catalysts, marked as Mn-40, Mn-100, and Mn-150, respectively. The catalytic activities of these catalysts and the effect of pore sizes on ethanol catalytic oxidation were investigated. Mn-40, Mn-100, and Mn-150 have triple, double, and single pore systems, respectively. On decreasing the aging temperature of KIT-6, the pore sizes of KIT-6 decrease and that of mesoporous MnO2 catalysts increase. The pore sizes and catalytic activities increase in the order: Mn-40 >Mn-100 > Mn-150. Mn-40 catalyst has a higher TOF (0.11 s−1 at 120 °C) and the best catalytic activity for ethanol oxidation because of a bigger pore size with three pore systems with maximum distribution at 1.9, 3.4, and 6.6 nm, decrease in symmetry and degree of order, more surface lattice oxygen species, oxygen vacancies resulting from more Mn3+ ions, and better low-temperature reducibility.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63036-0
       
  • Synthesis of TiO2 mesocrystal film with enhanced photocatalytic activity
    • Authors: Lili Ling; Longfei Liu; Yawei Feng; Jian Zhu; Zhenfeng Bian
      Pages: 639 - 645
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Lili Ling, Longfei Liu, Yawei Feng, Jian Zhu, Zhenfeng Bian
      TiO2 mesocrystals can considerably enhance charge separation owing to their oriented superstructures, with fewer internal defects and porous properties providing more active sites. In this work, we prepared TiO2 mesocrystal films by a direct annealing method. The morphology and crystal phase of the film were controlled by adjusting the ratio of NH4F and the calcination temperature. Moreover, we found that Au nanoparticles loaded on a TiO2 mesocrystal film enabled highly efficient visible light photocatalytic properties. The photocatalytic activities were studied by hydrogen generation and photoreduction of Cr(VI). This work represents a considerable advance in the development and application of the TiO2 mesocrystals.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)62980-2
       
  • Enhanced visible-light photocatalytic performance of a monolithic tungsten
           oxide/graphene oxide aerogel for nitric oxide oxidation
    • Authors: Li Yang; Yang Liu; Ruiyang Zhang; Wei Li; Pu Li; Xin Wang; Ying Zhou
      Pages: 646 - 653
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Li Yang, Yang Liu, Ruiyang Zhang, Wei Li, Pu Li, Xin Wang, Ying Zhou
      Photocatalysis is considered a promising technique for removal of pollutants from indoor air. However, the low selectivity and limited recyclability of photocatalysts in powder form currently limit their practical application. In this work, we reported the successful preparation of a monolithic tungsten oxide (WO3)/graphene oxide (GO) aerogel photocatalyst through a cost-effective freeze-drying method. GO not only acts as a macroscopic support, but also increases the catalyst surface area from 46 to 57 m2/g, enhances the light absorption in the visible-light region, and raises the separation efficiency of photogenerated electron-hole pairs. The Obtained WO3/GO aerogel exhibited an outstanding visible-light photocatalytic degradation rate of nitric oxide of 51%, which was 3.3 times that of pristine WO3 powder. In addition, the aerogel displayed excellent selectivity, with a generation fraction of toxic nitrogen dioxide of as low as 0.5%. This work presents a facile synthesis route to fabricate a monolithic WO3/GO aerogel photocatalyst with great promise for air purification.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)62974-7
       
  • Formation of BiOI/g-C3N4 nanosheet composites with high
           visible-light-driven photocatalytic activity
    • Authors: Hua An; Bo Lin; Chao Xue; Xiaoqing Yan; Yanzhu Dai; JinJia Wei; Guidong Yang
      Pages: 654 - 663
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Hua An, Bo Lin, Chao Xue, Xiaoqing Yan, Yanzhu Dai, JinJia Wei, Guidong Yang
      Constructing binary heterojunctions is an important strategy to improve the photocatalytic performance of graphitic carbon nitride (g-C3N4). In this paper, a novel g-C3N4 nanosheet-based composite was constructed via in situ growth of bismuth oxyiodide (BiOI) nanoplates on the surface of g-C3N4 nanosheets. The crystal phase, microstructure, optical absorption and textural properties of the synthesized photocatalysts were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy (DRS), and nitrogen adsorption-desorption isotherm measurements. The BiOI/g-C3N4 nanosheet composite showed high activity and recyclability for the photodegradation of the target pollutant rhodamine B (RhB). The conversion of RhB (20 mg L−1) by the photocatalyst was nearly 100% after 50 min under visible-light irradiation. The high photoactivity of the BiOI/g-C3N4 nanosheet composite can be attributed to the enhanced visible-light absorption of the g-C3N4 nanosheets sensitized by BiOI nanoplates as well as the high charge separation efficiency obtained by the establishment of an internal electric field between the n-type g-C3N4 and p-type BiOI. Based on the characterization and experimental results, a double-transfer mechanism of the photoinduced electrons in the BiOI/g-C3N4 nanosheet composite was proposed to explain its activity. This work represents a new strategy to understand and realize the design and synthesis of g-C3N4 nanosheet-based heterojunctions that display highly efficient charge separation and transfer.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)62927-9
       
  • Cobalt nanoparticles encapsulated in nitrogen-doped carbon for
           room-temperature selective hydrogenation of nitroarenes
    • Authors: Ruijie Gao; Lun Pan; Zhengwen Li; Xiangwen Zhang; Li Wang; Ji-Jun Zou
      Pages: 664 - 672
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Ruijie Gao, Lun Pan, Zhengwen Li, Xiangwen Zhang, Li Wang, Ji-Jun Zou
      Here, we report cobalt nanoparticles encapsulated in nitrogen-doped carbon (Co@NC) that exhibit excellent catalytic activity and chemoselectivity for room-temperature hydrogenation of nitroarenes. Co@NC was synthesized by pyrolyzing a mixture of a cobalt salt, an inexpensive organic molecule, and carbon nitride. Using the Co@NC catalyst, a turnover frequency of ∼12.3 h−1 and selectivity for 4-aminophenol of >99.9% were achieved for hydrogenation of 4-nitrophenol at room temperature and 10 bar H2 pressure. The excellent catalytic performance can be attributed to the cooperative effect of hydrogen activation by electron-deficient Co nanoparticles and energetically preferred adsorption of the nitro group of nitroarenes to electron-rich N-doped carbon. In addition, there is electron transfer from the Co nanoparticles to N-doped carbon, which further enhances the functionality of the metal center and carbon support. The catalyst also exhibits stable recycling performance and high activity for nitroaromatics with various substituents.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)62988-7
       
  • Promotional effects of Sb on Pd-based catalysts for the direct synthesis
           of hydrogen peroxide at ambient pressure
    • Authors: Doudou Ding; Xingyan Xu; Pengfei Tian; Xianglin Liu; Jing Xu; Yi-Fan Han
      Pages: 673 - 681
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Doudou Ding, Xingyan Xu, Pengfei Tian, Xianglin Liu, Jing Xu, Yi-Fan Han
      TiO2-supported Pd-Sb bimetallic catalysts were prepared and evaluated for the direct synthesis of H2O2 at ambient pressure. The addition of Sb to Pd significantly enhanced catalytic performance, and a Pd50Sb catalyst showed the greatest selectivity of up to 73%. Sb promoted the dispersion of Pd on TiO2, as evidenced by transmission electron microscopy and X-ray diffraction. X-ray photoelectron spectroscopy indicated that the oxidation of Pd was suppressed by Sb. In addition, Sb2O3 layers were formed and partially wrapped the surfaces of Pd catalysts, thus suppressing the activation of H2 and subsequent hydrogenation of H2O2. In situ diffuse reflection infrared Fourier transform spectroscopy for CO adsorption suggested that Sb homogenously located on the surface of Pd-Sb catalysts and isolated contiguous Pd sites, resulting in the rise of the ratio of Pd monomer sites that are favorable for H2O2 formation. As a result, the Sb modified Pd surfaces significantly enhanced the non-dissociative activation of O2 and H2O2 selectivity.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63031-1
       
  • Hydrothermal synthesis of CeO2/NaNbO3 composites with enhanced
           photocatalytic performance
    • Authors: Jin Qian; Yao Xue; Yanhui Ao; Peifang Wang; Chao Wang
      Pages: 682 - 692
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Jin Qian, Yao Xue, Yanhui Ao, Peifang Wang, Chao Wang
      A highly active photocatalyst CeO2/NaNbO3 is fabricated by a simple and facile hydrothermal method. The obtained photocatalyst composites are characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and ultraviolet-visible diffuse reflectance spectroscopy. The photocatalytic activity of the obtained samples is demonstrated by the photocatalytic degradation of the colorless antibiotic agent ciprofloxacin and the dye rhodamine B. The results reveal that CeO2/NaNbO3 composites exhibit a higher photocatalytic property than pure NaNbO3 under both UV and visible light irradiation. Furthermore, the optimum mass ratio of CeO2 in the CeO2/NaNbO3 composites is 2.0 wt%. The improved photocatalytic activity is attributed to the higher separation rate of the photo-induced electrons and holes, and the higher migration rate of the photogenerated charge in the interfacial region. Furthermore, the photoluminescence pectra, photocurrent, electrochemical impedance spectroscopy and trapping experiment are applied to demonstrate the photocatalytic reaction mechanism of the as-prepared samples. The result of the trapping experiment indicates that •OH radicals, •O2 − radicals and holes are all involved in the photocatalytic degradation process of RhB. Furthermore, a possible mechanism for the enhancement of the photocatalytic activity is also proposed.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)62975-9
       
  • Palladium nanoparticles assembled on titanium nitride for enhanced
           electrochemical hydrodechlorination of 2,4-dichlorophenol in water
    • Authors: Wenyang Fu; Kaifeng Wang; Xiaoshu Lv; Hailu Fu; Xingan Dong; Ling Chen; Xianming Zhang; Guangming Jiang
      Pages: 693 - 700
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Wenyang Fu, Kaifeng Wang, Xiaoshu Lv, Hailu Fu, Xingan Dong, Ling Chen, Xianming Zhang, Guangming Jiang
      We report a one-pot surfactant-free wet-chemical reduction approach to the synthesis of palladium/titanium nitride (Pd/TiN) and Pd/carbon (Pd/C) composites, in which ∼5 nm Pd NPs were uniformly dispersed on TiN or C. In terms of catalytic performance, Pd/TiN showed enhanced efficiency and stability compared with those of Pd/C and bare TiN in the electrocatalytic hydrodechlorination (EHDC) reaction of 2,4-dichlorophenol (2,4-DCP) in aqueous solution. The superior performance of Pd/TiN arises from the promotion effect of TiN. Strong metal-support interactions modified the electronic structure of Pd, which optimized generation of H* ads and 2,4-DCP adsorption/activation. The cathode potential plays a vital role in controlling the EHDC efficiency and the product distribution. A working potential of –0.80 V was shown to be optimal for achieving the highest EHDC efficiency and maximizing conversion of 2,4-DCP to phenol (P). Our studies of the reaction pathway show that EHDC of 2,4-DCP on Pd/TiN proceeded by 2,4-DCP→p-chlorophenol (p-CP), o-chlorophenol (o-CP)→P; however, Pd/TiN presented little selectivity for cleavage of p-C-Cl vs o-C-Cl. This work presents a new approach to enhancing Pd performance towards EHDC through the effects of a support. The strategy demonstrated here could also be extended to design highly efficient catalysts for other hydrogenation reactions.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)62937-1
       
  • Enhancement of UV-assisted TiO2 degradation of ibuprofen using Fenton
           hybrid process at circumneutral pH
    • Authors: Meijuan Chen; Wei Chu; Jingzi Beiyuan; Yu Huang
      Pages: 701 - 709
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Meijuan Chen, Wei Chu, Jingzi Beiyuan, Yu Huang
      A synergistic UV/TiO2/Fenton (PCF) process is investigated for the degradation of ibuprofen (IBP) at circumneutral pH. The IBP decay in the PCF process is much faster than that with the conventional UV, UV/H2O2, Fenton, photo-Fenton, and photocatalysis processes. The kinetics analysis showed that the IBP decay follows a two-stage pseudo-first order profile, that is, a fast IBP decay (k 1) followed by a slow decay (k 2). The effects of various parameters, including initial pH level, dosage of Fenton's reagent and TiO2, wavelength of UV irradiation, and initial IBP concentration, are evaluated. The optimum pH level, [Fe2+]0, [Fe2+]0/[H2O2]0 molar ratio, and [TiO2]0 are determined to be approximately 4.22, 0.20 mmol/L, 1/40, and 1.0 g/L, respectively. The IBP decay at circumneutral pH (i.e., 6.0–8.0 for wastewater) shows the same IBP decay efficiency as that at the optimum pH of 4.22 after 30 min, which suggests that the PCF process is applicable for the treatment of wastewater in the circumneutral pH range. The lnk 1 and lnk 2 are observed to be linearly correlated to 1/pH0, [IBP]0, [H2O2]0, [H2O2]0/[Fe2+]0 and ln[TiO2]0. Mathematical models are therefore derived to predict the IBP decay.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63070-0
       
  • The effect of cations (NH4+, Na+, K+, and Ca2+) on chemical deactivation
           of commercial SCR catalyst by bromides
    • Authors: Huazhen Chang; Chuanning Shi; Mingguan Li; Tao Zhang; Chizhong Wang; Lilong Jiang; Xiuyun Wang
      Pages: 710 - 717
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Huazhen Chang, Chuanning Shi, Mingguan Li, Tao Zhang, Chizhong Wang, Lilong Jiang, Xiuyun Wang
      Alkali and alkaline-earth metals from fly ash have a significant deactivation effect on catalysts used for selective catalytic reduction of NO x by NH3 (NH3-SCR). Bromides are considered effective additives to improve Hg0 oxidation on SCR catalysts. In this work, the effects of different bromides (NH4Br, NaBr, KBr, and CaBr2) on a commercial V2O5-WO3/TiO2 catalyst were studied. NO x conversion decreased significantly over the KBr-poisoned catalyst (denoted as L-KBr), while that over NaBr- and CaBr2-poisoned catalysts (denoted as L-NaBr and L-CaBr, respectivity) decreased to a lesser extent compared with the fresh sample. Poor N2 selectivity was observed over L-NaBr, L-KBr and L-CaBr catalysts. The decrease in the ratio of chemisorbed oxygen to total surface oxygen (Oα/(Oα + Oβ + Ow)), reducibility and surface acidity might contribute to the poor activity and N2 selectivity over L-KBr catalyst. The increased Oα ratio was conducive to the enhanced reducibility of L-CaBr. Combined with enhanced surface acidity, this might offset the negative effect of the loss of active sites by CaBr2 covering. The overoxidation of NH3 and poor N2 selectivity in NH3 oxidation should retard the SCR activity at high temperatures over L-CaBr catalyst. The increased basicity might contribute to increased NO x adsorption on L-KBr and L-CaBr catalysts. A correlation between the acid-basic and redox properties of bromide-poisoned catalysts and their catalytic properties is established.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63011-6
       
  • In-situ transformation of Bi2WO6 to highly photoreactive Bi2WO6@Bi2S3
           nanoplate via ion exchange
    • Authors: Tingting Huang; Yuhan Li; Xiaofeng Wu; Kangle Lv; Qin Li; Mei Li; Dongyun Du; Hengpeng Ye
      Pages: 718 - 727
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Tingting Huang, Yuhan Li, Xiaofeng Wu, Kangle Lv, Qin Li, Mei Li, Dongyun Du, Hengpeng Ye
      As a two dimensional (2D) visible-light-responsive semiconductor photocatalyst, the photoreactivity of Bi2WO6 is not high enough for practical application owing to its limited response to visible light and rapid recombination of photogenerated electron-hole pairs. In this paper, 2D core-shell structured Bi2WO6@Bi2S3 nanoplates were prepared by calcination of a mixture of Bi2WO6 (1.3 g) and a certain amount of Na2S·9H2O (0–3.0 g) at 350 °C for 2 h. The reactivity of the resulting photocatalyst materials was evaluated by photocatalytic degradation of Brilliant Red X-3B (X3B), an anionic dye, under visible light irradiation (λ > 420 nm). As the amount of Na2S·9H2O was increased from 0 to 1.5 g, the degradation rate constant of X3B sharply increased from 0.40 × 10−3 to 6.6 × 10−3 min−1. The enhanced photocatalytic activity of Bi2WO6@Bi2S3 was attributed to the photosensitization of Bi2S3, which greatly extended the light-responsive range from the visible to the NIR, and the formation of a heterojunction, which retarded the recombination rate of photogenerated electron-hole pairs. However, further increases in the amount of Na2S·9H2O (from 1.5 to 3.0 g) resulted in a decrease of the photocatalytic activity of the Bi2WO6@Bi2S3 nanoplates owing to the formation of a photo-inactive NaBiS2 layer covering the Bi2WO6 surface.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)62913-9
       
  • Supercritical water syntheses of transition metal-doped CeO2
           nano-catalysts for selective catalytic reduction of NO by CO: An in situ
           diffuse reflectance Fourier transform infrared spectroscopy study
    • Authors: Xiaoxia Dai; Weiyu Jiang; Wanglong Wang; Xiaole Weng; Yuan Shang; Yehui Xue; Zhongbiao Wu
      Pages: 728 - 735
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Xiaoxia Dai, Weiyu Jiang, Wanglong Wang, Xiaole Weng, Yuan Shang, Yehui Xue, Zhongbiao Wu
      In the present study, we synthesized CeO2 catalysts doped with various transition metals (M = Co, Fe, or Cu) using a supercritical water hydrothermal route, which led to the incorporation of the metal ions in the CeO2 lattice, forming solid solutions. The catalysts were then used for the selective catalytic reduction (SCR) of NO by CO. The Cu-doped catalyst exhibited the highest SCR activity; it had a T 50 (i.e., 50% NO conversion) of only 83 °C and a T 90 (i.e., 90% NO conversion) of 126 °C. Such an activity was also higher than in many state-of-the-art catalysts. In situ diffuse reflectance Fourier transform infrared spectroscopy suggested that the MO x -CeO2 catalysts (M = Co and Fe) mainly followed an Eley-Rideal reaction mechanism for CO-SCR. In contrast, a Langmuir-Hinshelwood SCR reaction mechanism occurred in CuO-CeO2 owing to the presence of Cu+ species, which ensured effective adsorption of CO. This explains why CuO-CeO2 exhibited the highest activity with regard to the SCR of NO by CO.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(17)63008-0
       
  • Enhanced visible photocatalytic activity of TiO2 hollow boxes modified by
           methionine for RhB degradation and NO oxidation
    • Authors: Xuan Zhao; Yanting Du; Chengjiang Zhang; Lijun Tian; Xiaofang Li; Kejian Deng; Lianqing Chen; Youyu Duan; Kangle Lv
      Pages: 736 - 746
      Abstract: Publication date: April 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 4
      Author(s): Xuan Zhao, Yanting Du, Chengjiang Zhang, Lijun Tian, Xiaofang Li, Kejian Deng, Lianqing Chen, Youyu Duan, Kangle Lv
      Hierarchical TiO2 hollow nanoboxes (TiO2-HNBs) assembled from TiO2 nanosheets (TiO2-NSs) show improved photoreactivity when compared with the building blocks of discrete TiO2-NSs. However, TiO2-HNBs can only be excited by ultraviolet light. In this paper, visible-light-responsive N and S co-doped TiO2-HNBs were prepared by calcining the mixture of cubic TiOF2 and methionine (C5H11NO2S), a N- and S-containing biomacromolecule. The effect of calcination temperature on the structure and performance of the TiO2-HNBs was systematically studied. It was found that methionine can prevent TiOF2-to-anatase TiO2 phase transformation. Both N and S elements are doped into the lattice of TiO2-HNBs when the mixture of TiOF2 and methionine undergoes calcination at 400 °C, which is responsible for the visible-light response. When compared with that of pure 400 °C-calcined TiO2-HNBs (T400), the photoreactivity of 400 °C-calcined methionine-modified TiO2-HNBs (TM400) improves 1.53 times in photocatalytic degradation of rhodamine-B dye under visible irradiation (λ > 420 nm). The enhanced visible photoreactivity of methionine-modified TiO2-HNBs is also confirmed by photocatalytic oxidation of NO. The successful doping of N and S elements into the lattice of TiO2-HNBs, resulting in the improved light-harvesting ability and efficient separation of photo-generated electron-hole pairs, is responsible for the enhanced visible photocatalytic activity of methionine-modified TiO2-HNBs. The photoreactivity of methionine modified TiO2-HNBs remains nearly unchanged even after being recycled five times, indicating its promising use in practical applications.
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      PubDate: 2018-04-25T00:51:57Z
      DOI: 10.1016/s1872-2067(18)63039-6
       
  • Chemical transformation of sugars into amino acids
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Tao Zhang
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      PubDate: 2018-06-01T05:47:02Z
       
  • In situ doping brushite on zinc manganese oxide toward enhanced water
           oxidation performance: Mimicry of an oxygen-evolving complex
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Miao Jiang, Junying Chen, Yingwei Li
      We report in situ doping of brushite on zinc manganese oxide (ZMO), fabricated by calcining a Mn(II) oxalate-impregnated metal-organic framework. The doping process was conducted in combination with the photocatalytic water oxidation reaction which was catalyzed by ZMO in neutral phosphate-buffered aqueous solution containing [Ru(bpy)3]2+-Na2S2O8 and calcium(II) triflate salt, exhibiting greatly enhanced water oxidation performance with optimized turnover frequency of 0.18 mmolO2 molMn −1 s−1. Different analytical techniques indicated that photodeposited calcium-phosphate (CaP) acted as a co-catalyst to promote the O2 evolution activity of ZMO. This system involved the use of manganese oxide and calcium ion, and the operation was conducted under ambient temperature and neutral conditions, thus, it efficiently mimicked the oxygen-evolving complex in photosystem II.
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      PubDate: 2018-06-01T05:47:02Z
       
  • Pt/Nb-WOx for the chemoselective hydrogenolysis of glycerol to
           1,3-propanediol: Nb dopant pacifying the over-reduction of WOx supports
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Man Yang, Xiaochen Zhao, Yujing Ren, Jia Wang, Nian Lei, Aiqin Wang, Tao Zhang
      Selective hydrogenolysis of glycerol to 1,3-propanediol (1,3-PD) is an important yet challenging method for the transformation of biomass into value-added chemicals due to steric hindrance and unfavorable thermodynamics. In previous studies, chemoselective performances were found demanding and sensitive to H2 pressure. In this regard, we manipulate the chemical/physical characteristics of the catalyst supports via doping Nb into WO x and prepared 1D needle-, 2D flake-, and 3D sphere-stack mesoporous structured Nb-WO x with increased surface acid sites. Moreover, Nb doping can successfully inhibit the over-reduction of active W species during glycerol hydrogenolysis and substantially broaden the optimal H2 pressure from 1 to 5 MPa. When Nb doping is 2%, supported Pt catalysts showed promising performance for the selective hydrogenolysis of glycerol to 1,3-PD over an unprecedentedly wide H2 pressure range, which will guarantee better catalyst stability in the long run, as well as expand their applications to other hydrogen-related reactions.
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      PubDate: 2018-06-01T05:47:02Z
       
  • N-doped carbon modified Pt/CNTs synthesized by atomic layer deposition
           with enhanced activity and stability for methanol electrooxidation
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Huimin Yang, Baiyan Zhang, Bin Zhang, Zhe Gao, Yong Qin
      A Pt/CNTs catalyst coated with N-doped carbon (xNC-Pt/CNTs) is synthesized by atomic layer deposition (ALD) and applied in methanol electrooxidation reaction. Pt nanoparticles and polyimide (PI) are sequentially deposited on carbon nanotubes (CNTs) by ALD. After annealing at 600 °C in H2 atmosphere, the PI is carbonized to produce porous N-doped carbon. Upon coating with a moderately thick layer of N-doped carbon, the optimized 50NC-Pt/CNTs show higher activity, better long-term stability, and improved CO resistance towards methanol electrooxidation compared with Pt/CNTs and commercial Pt/C (20 wt%). X-ray photoelectron spectroscopy characterization result indicates that the Pt–CO bond is weakened after N-doped carbon coating and CO adsorption on the Pt surface is weakened, leading to superior electrocatalytic performance.
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      PubDate: 2018-06-01T05:47:02Z
       
  • Facile in-situ synthesis and deposition of monodisperse palladium
           nanoparticles on polydopamine-functionalized silica gel as a heterogeneous
           and recyclable nanocatalyst for aerobic oxidation of alcohols
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Hojat Veisi, Ahmad Nikseresht, Shahin Mohammadi, Saba Hemmati
      This paper describes a facile in-situ synthesis of palladium nanoparticles (Pd NPs) on silica gel/polydopamine composite (SiO2/PDA) without any stabilizer or reducing agent. In this approach, palladium ions were adsorbed on SiO2/PDA surfaces by immersing the PDA-coated SiO2 particles in a palladium plating bath. Then, they were reduced in situ to Pd nanoclusters by the reducing ability of PDA's N-containing groups. The structure, morphology, and physicochemical properties of the synthesized nanocomposites were characterized by different analytical techniques such as high-resolution transmission electron microscopy, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy, inductively coupled plasma and Fourier-transform infrared spectroscopy. The Pd NPs capped by the PDA groups had a strikingly small size (30–40 nm). SiO2/PDA/Pd NPs exhibited high catalytic activity as a recyclable nanocatalyst in the aerobic oxidation of alcohols. Furthermore, recovery and multiple reuse of the catalyst revealed no detectable activity loss.
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      PubDate: 2018-06-01T05:47:02Z
       
  • Preparation of a fullerene[60]-iron oxide complex for the photo-fenton
           degradation of organic contaminants under visible-light irradiation
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Cong-yang Zou, Ze-da Meng, Wen-chao Ji, Shou-qing Liu, Zhemin Shen, Yuan Zhang, Ni-shan Jiang
      Iron oxide (Fe2O3) was doped onto fullerene[60] (C60) to form a C60-Fe2O3 composite using an easy and scalable impregnation method. The as-prepared C60-Fe2O3 samples were characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, UV-vis absorption spectroscopy, Raman spectroscopy, and Fourier transform infrared spectroscopy. The photocatalytic activity of the C60-Fe2O3 catalyst was evaluated by examining the degradation of methylene blue (MB), rhodamine B (RhB), methyl orange (MO), and phenol under visible light (λ > 420 nm) in the presence of hydrogen peroxide. The results showed that the catalyst exhibited excellent catalytic properties over a wide pH range 3.06–10.34. Under optimal conditions, 98.9% discoloration and 71% mineralization of MB were achieved in 80 min. Leaching test results indicated that the leaching of iron from the catalyst was negligible and that the catalyst had a high photocatalytic activity after five reaction cycles. The catalyst was also efficient in the degradation of RhB, MO, and phenol. These findings could be attributed to the synergetic effects of C60 and Fe2O3. We used active species trapping experiments to determine the main active oxidant in the photocatalytic reaction process and found that hydroxyl radicals played a major role in the entire process.
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      PubDate: 2018-06-01T05:47:02Z
       
  • Acid-promoted Ir-La-S/AC-catalyzed methanol carbonylation on single atomic
           active sites
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Zhou Ren, Yuan Lyu, Siquan Feng, Xiangen Song, Yunjie Ding
      Highly active Ir-La-S/AC catalyst was successfully prepared by co-impregnation of an activated carbon (AC) carrier with a sulfuric acid solution of Ir and La species and compared with a traditionally prepared Ir-La/AC catalyst. High angle annular dark-field-scanning transmission electron microscopy (HAADF-STEM) measurement results show that most of the Ir species on Ir-La-S/AC exist as single atomic sites, while those on Ir-La/AC exist as nanoparticles with an average diameter of 1.5 nm. Evaluation of Ir-La-S/AC as a catalyst for heterogeneous carbonylation of methanol to acetyl gave a maximum TOF (turn-over-frequency) of 2760 h−1, which was distinctly higher than that achieved by the Ir-La/AC catalyst (approximately 1000 h−1). Temperature-programmed desorption of ammonia (NH3-TPD) result shows that the addition of sulfuric acid during the preparation procedure results in significantly more acidic sites on Ir-La-S/AC than those on Ir-La/AC, which plays a key role in the enhancement of CO insertion as the rate-determining step. Temperature-programmed reduction (TPR) and in situ X-ray photoelectron spectroscopy reveal that Ir species are more reducible, and that more Ir+ might be formed by activation of Ir-La-S/AC than those on the Ir-La/AC catalyst, which is thought to be beneficial for reductive elimination of AcI from Ir3+ species as an essential step for CH3I regeneration and acetyl formation.
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      PubDate: 2018-06-01T05:47:02Z
       
  • Hydrogenation of 2-ethylanthraquinone with bimetallic monolithic
           catalysts: An experimental and DFT study
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Yanyan Guo, Chengna Dai, Zhigang Lei
      We studied the hydrogenation of 2-ethylanthraquinone (eAQ) over Pd/SiO2/COR (COR = cordierite) monometallic and Pd-M/SiO2/COR (M = Ni, Fe, Mn, and Cu) bimetallic monolithic catalysts, which were prepared by the co-impregnation method. Detailed investigations showed that the particle sizes and structures of the Pd-M (M = Ni, Fe, Mn, and Cu) bimetallic monolithic catalysts were greatly affected by the second metal M and the mass ratio of Pd to the second metal M. By virtue of the small particle size and the strong interaction between Pd and Ni of Pd-Ni alloy, Pd-Ni bimetallic monolithic catalysts with the mass ratio of Pd/Ni = 2 achieved the highest H2O2 yield (7.5 g/L) and selectivity (95.3%). Moreover, density functional theory calculations were performed for eAQ adsorption to gain a better mechanistic understanding of the molecule-surface interactions between eAQ and the Pd(1 1 1) or PdM(1 1 1) (M = Ni, Fe, Mn, and Cu) surfaces. It was found that the high activity of the bimetallic Pd-Ni catalyst was a result of strong chemisorption between Pd3Ni1 (1 1 1) and the carbonyl group of eAQ.
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      PubDate: 2018-06-01T05:47:02Z
       
  • Green catalytic oxidation of benzyl alcohol over Pt/ZnO in base-free
           aqueous medium at room temperature
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Juanjuan Liu, Shihui Zou, Jiachao Wu, Hisayoshi Kobayashi, Hongting Zhao, Jie Fan
      The selective oxidation of alcohol using molecular oxygen as an oxidant and water as a green solvent is of great interest in green chemistry. In this work, we present a systematic study of a Pt/ZnO catalyst for the selective oxidation of benzyl alcohol at room temperature under base-free aqueous conditions. Experimental observations and density functional theory calculations suggest that ZnO as a support can facilitate the adsorption of benzyl alcohol, which subsequently reacts with the activated oxygen species on the Pt catalyst, producing benzaldehyde. The resulting solid achieves a high conversion (94.1 ± 5.1% in 10 h) of benzyl alcohol and nearly 100% selectivity to benzaldehyde with ambient air as the oxidant. In addition, by introducing a small amount of Bi (1.78 wt%) into Pt/ZnO, we can further enhance the activity by 350%.
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      PubDate: 2018-06-01T05:47:02Z
       
  • Preparation of N-vacancy-doped g-C3N4 with outstanding photocatalytic H2O2
           production ability by dielectric barrier discharge plasma treatment
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Xuhe Li, Jian Zhang, Feng Zhou, Hongliang Zhang, Jin Bai, Yanjuan Wang, Haiyan Wang
      Dielectric barrier discharge (DBD) plasma is considered to be a promising method to synthesize solid catalysts. In this work, DBD plasma was used to synthesize a nitrogen-vacancy-doped g-C3N4 catalyst in situ for the first time. X-ray diffraction, N2 adsorption, ultraviolet–visible spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy, electron paramagnetic resonance, O2 temperature-programmed desorption, and photoluminescence were used to characterize the obtained catalysts. The photocatalytic H2O2 production ability of the as-prepared catalyst was investigated. The results show that plasma treatment influences the morphology, structure, and optical properties of the as-prepared catalyst. Nitrogen vacancies are active centers, which can adsorb reactant oxygen molecules, trap photoelectrons, and promote the transfer of photoelectrons from the catalyst to the adsorbed oxygen molecules for the subsequent reduction reaction. This work provides a new strategy for synthesizing g-C3N4-based catalysts.
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      PubDate: 2018-06-01T05:47:02Z
       
  • Preparation and catalytic properties of mesoporous nV-MCM-41 for propane
           oxidative dehydrogenation in the presence of CO2
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Zai-Fang Han, Xu-Liang Xue, Jian-Min Wu, Wan-Zhong Lang, Ya-Jun Guo
      The nV-MCM-41 catalysts were prepared by one-step hydrothermal synthesis and applied to the oxidative dehydrogenation of propane (ODHP) in the presence of CO2. Several state-of-the-art characterization methods were performed to explore the correlation between catalytic performance and the physicochemical characterizations of the catalysts. Because moderate amounts of V species were introduced into the framework of MCM-41, the catalyst maintained a large specific surface area, a highly ordered mesoporous structure, and highly dispersed V active sites (monomeric and dimeric V oxide species), while the high-vanadium-doping catalysts caused an enhancement in the number of acidic sites and V2O5 crystallites. The ODHP reaction showed that the 6.8V-MCM-41 (V content 6.8 wt%) catalyst exhibits high activity and stability, and the C3H8/CO2 molar ratio (1:4) was suitable. The promoting effect of CO2 on the oxidative dehydrogenation of ODHP was demonstrated as the reaction coupling mechanism and “lattice oxygen” mechanism.
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      PubDate: 2018-06-01T05:47:02Z
       
  • Olefin oligomerization via new and efficient Brönsted acidic ionic
           liquid catalyst systems
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Guoqin Wang, Heyuan Song, Ruiyun Li, Zhen Li, Jing Chen
      Olefin oligomerization reaction catalyzed by new catalyst systems (a Brönsted-acidic ionic liquid as the main catalyst and tricaprylylmethylammonium chloride as the co-catalyst) has been investigated. The synthesized Brönsted acidic ionic liquids were characterized by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV), 1H nuclear magnetic resonance (NMR), and 13C NMR to analyze their structures and acidities. The influence of different ionic liquids, ionic liquid loading, different co-catalysts, catalyst ratios (mole ratio of ionic liquid to co-catalyst), reaction time, pressure, temperature, solvent, source of reactants, and the recycling of catalyst systems was studied. Among the synthesized ionic liquids, 1-(4-sulfonic acid)butyl-3-hexylimidazolium hydrogen sulfate ([HIMBs]HSO4) exhibited the best catalytic activity under the tested reaction conditions. The conversion of isobutene and selectivity of trimers were 83.21% and 35.80%, respectively, at the optimum reaction conditions. Furthermore, the catalyst system can be easily separated and reused; a feasible reaction mechanism is proposed on the basis of the distribution of experimental products.
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      PubDate: 2018-06-01T05:47:02Z
       
  • Glycerol hydrogenolysis to n-propanol over Zr-Al composite oxide-supported
           Pt catalysts
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Chuang Li, Bo He, Yu Ling, Chi-Wing Tsang, Changhai Liang
      Zr-Al mixed oxide supported Pt catalysts with different Zr/Al mole ratios (2.5%Pt/Zr x Al1–x O y ) were synthesized by an impregnation method and used for the selective hydrogenolysis of glycerol to n-propanol in an autoclave reactor. The catalysts were fully characterized by X-ray powder diffraction, Brunauer-Emmett-Teller surface area analysis, CO chemisorption, H2 temperature- programmed reduction, pyridine-infrared spectroscopy, and NH3-temperature-programmed desorption. The results revealed that the Zr/Al ratio on the support significantly affected the size of the platinum particles and the properties of the acid sites on the catalysts. The catalytic performance was well correlated with the acidic properties of the catalyst; specifically, more acid sites contributed to the conversion and strong acid sites with a specific intensity contributed to the deep dehydration of glycerol to form n-propanol. Among the tested catalysts, 2.5 wt% Pt/Zr0.7Al0.3O y exhibited excellent selectivity for n-propanol with 81.2% glycerol conversion at 240 °C and 6.0 MPa H2 pressure when 10% aqueous glycerol solution was used as the substrate. In addition, the effect of various reaction parameters, such as H2 content, reaction temperature, reaction time, and number of experimental cycles were studied to determine the optimized reaction conditions and to evaluate the stability of the catalyst.
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      PubDate: 2018-06-01T05:47:02Z
       
  • One-step aldol condensation reaction of dimethoxymethane and methyl
           acetate over supported Cs/ZSM-35 zeolite catalysts
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Zhanling Ma, Xiangang Ma, Hongchao Liu, Wenliang Zhu, Xinwen Guo, Zhongmin Liu
      This study was performed for the development of a green and promising approach for the synthesis of methyl acrylate and acrylic acid by a one-step aldol condensation reaction of dimethoxymethane and methyl acetate over cesium oxide-supported on ZSM-35 zeolite catalysts; the effect of base sites as well as acid sites on the aldol condensation reaction was studied in detail. It was found that base sites were harmful for aldol condensation due to their failure in catalyzing the decomposition of dimethoxymethane precursor into formaldehyde, whereas the acid site was indispensable for the reaction to proceed. This reaction cannot take place without an acid site. Although acid sites in H-form of the zeolite (HZSM-35) are indispensable for the aldol condensation reaction, not all of them tend to favor this reaction. A strong acid catalyzes methanol-to-olefin-like reactions resulting in hydrocarbon byproducts, which are finally transferred to hard coke. Medium strong acids and weak acids are great candidates for the target aldol condensation reaction with high activity and selectivity. A γ-Al2O3 sample with abundant weak-strength Lewis acid sites, together with a few medium-strong-strength acid sites, performs well with a high activity and considerable stability during the synthesis of methyl acrylate and acrylic acid.
      Graphical abstract image

      PubDate: 2018-06-01T05:47:02Z
       
  • Simple synthesis of nitrogen-doped carbon spheres as a highly efficient
           metal-free electrocatalyst for the oxygen reduction reaction
    • Abstract: Publication date: June 2018
      Source:Chinese Journal of Catalysis, Volume 39, Issue 6
      Author(s): Jinhui Tong, Wenyan Li, Lili Bo, Wenhui Wang, Yuliang Li, Tao Li, Qi Zhang, Haiyan Fan
      In the present work, nitrogen-doped carbon spheres were synthesized through a simple hydrothermal treatment using glucose and melamine as inexpensive carbon and nitrogen sources, respectively. The ratio of melamine to glucose and annealing temperature were optimized. The final optimal sample exhibited a catalytic activity for the oxygen reduction reaction (ORR) that was superior than that of commercial 20%Pt/C in 0.1 mol/L KOH. It revealed an onset potential of –22.6 mV and a half-wave potential of –133.6 mV (vs. Ag/AgCl), which are 7.2 and 5.9 mV more positive than those of the 20%Pt/C catalyst, respectively, as well as a limiting current density of 4.6 mA/cm2, which is 0.2 mA/cm2 higher than that of the 20%Pt/C catalyst. The catalyst also exhibited higher stability and superior durability against methanol than 20%Pt/C. Moreover, ORRs on this catalyst proceed through a more effective 4e− path. The above mentioned superiority of the as-prepared catalyst makes it promising for fuel cells.
      Graphical abstract image

      PubDate: 2018-06-01T05:47:02Z
       
 
 
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