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  • Sunlight-promoted direct irradiation of N-centred anion: the photocatalyst-free synthesis of pyrazoles in water
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-20
    Te Zhang, Yunge Meng, Jinye Lu, Yuting Yang, Gong-Qiang Li, Chunyin Zhu

    A practical method through sunlight mediated annulation of α, β-unsaturated hydrazones has been developed for the synthesis of pyrazole. Based on the analysis of UV-Vis absorption of the substrate, the reaction was designed to avoid the use of external photocatalysis and proceeds via direct irradiation of N-centred anion by sunlight. The key features of this reaction include operational simplicity, readily available reagents, and amenability to gram-scale synthesis.

    更新日期:2017-11-20
  • Electrochemical Behavior of Stainless Steels for Sudomotor Dysfunction Applications
    Electroanalysis (IF 2.851) Pub Date : 2017-11-20
    A. Calmet, N. Vejar, X. Gonzalez, M. Sancy, A. Ringuedé, V. Lair, S. Griveau, J.H. Zagal, F. Bedioui, M. Cassir
    更新日期:2017-11-20
  • Planar model system of the Phillips (Cr/SiO2) catalyst based on a well-defined thin silicate film
    J. Catal. (IF 6.844) Pub Date : 2017-11-16
    Qiushi Pan, Linfei Li, Shamil Shaikhutdinov, Hans-Joachim Freund
    更新日期:2017-11-20
  • Single cobalt sites in mesoporous N-doped carbon matrix for selective catalytic hydrogenation of nitroarenes
    J. Catal. (IF 6.844) Pub Date : 2017-11-20
    Xiaohui Sun, Alma I. Olivos-Suarez, Dmitrii Osadchii, Maria Jose Valero Romero, Freek Kapteijn, Jorge Gascon
    更新日期:2017-11-20
  • Role of Brønsted acid site during catalytic combustion of methane over PdO/ZSM-5: Dominant or negligible?
    J. Catal. (IF 6.844) Pub Date : 2017-11-20
    Qiguang Dai, Qin Zhu, Yang Lou, Xingyi Wang
    更新日期:2017-11-20
  • Improvement of Thermal Stability of Microporous TiO2 for NH3-SCR Reaction Using Multivalent Cations
    Catal. Today (IF 4.636) Pub Date : 2017-11-16
    Soon Hee Park, Seung Gwan Lee, Sung June Cho

    The thermal stability of polycrystalline microporous TiO2 (m-TiO2) has been improved by incorporating multivalent cations such as La3+ and Ce3+. The changes in the crystal structure upon heating were monitored using X-ray powder diffraction and N2 adsorption-desorption isotherms. The presence of multivalent cations significantly increased the thermal stability of TiO2, as inferred from the changes in the surface area, pore volume, and X-ray diffraction pattern. The catalytic performance of the pristine V/m-TiO2 catalyst in the NH3-SCR reaction increased from 40% to 70% and 80% by using the V/m-TiO2 catalyst containing La3+ and Ce3+, respectively, after thermal treatment at 500 °C for 2 h. Further it was demonstrated that the addition of WOx onto La3+ or Ce3+ modified m-TiO2 affected the corresponding thermal stability and the catalytic performance, suggesting that the Ce3+ seemed to be best for the improvement of thermal stability.

    更新日期:2017-11-20
  • INTERCONNECTION BETWEEN FEED COMPOSITION AND Ni/Co RATIO IN (La-Ni-Co-O)-BASED PEROVSKITES AND ITS EFFECTS ON THE STABILITY OF LPG STEAM REFORMING
    Appl. Catal. A Gen. (IF 4.339) Pub Date : 2017-11-20
    Cícero N. Ávila-Neto, Kátia D. Oliveira, Kimberly F. Oliveira, Aline M.M. Arouca, Rondinele A.R. Ferreira, Carla E. Hori

    Nickel-based perovskites (La-Ni-O) partially substituted with cobalt were tested for steam reforming of Liquefied Petroleum Gas (LPG), and analyzed by a series of in situ techniques. In situ X-ray diffraction (XRD) analyses showed that, depending on the fraction of substituted Ni, the perovskites go through one or two reduction stages before decomposing into Ni0/Co0 and La2O3. Extended X-ray absorption fine structure (EXAFS) data indicated that the nanoparticle’s surface are enriched with Co after reduction, but the Ni atoms migrate to the surface and overlay the former Co shell soon after feeding the LPG steam reforming mixture. In samples synthesized with a low Co/Ni ratio, the Ni surface layer oxidizes after a few hours under reaction conditions, showing signs of deactivation. The oxidation could be prevented by decreasing the water/LPG feed ratio, which reactivated the catalyst. The use of a proper water/LPG feed ratio coupled with the suitable Co/Ni ratio in the synthesis of perovskite precursors is essential to keep the catalysts active during LPG steam reform.

    更新日期:2017-11-20
  • Uncovering the 3 D Structure of Combustion-Synthesized Noble Metal-Ceria Nanocatalysts
    ChemCatChem (IF 4.803) Pub Date : 2017-11-20
    Lucian Roiban, Siddardha Koneti, Franck Morfin, Thanh-Son Nguyen, Pascale Mascunan, Mimoun Aouine, Thierry Epicier, Laurent Piccolo
    更新日期:2017-11-20
  • Mechanisms of Two-Electron versus Four-Electron Reduction of Dioxygen Catalyzed by Earth-Abundant Metal Complexes
    ChemCatChem (IF 4.803) Pub Date : 2017-11-20
    Shunichi Fukuzumi, Yong-Min Lee, Wonwoo Nam
    更新日期:2017-11-20
  • Methanation of CO2 over alkali-promoted Ru/TiO2 catalysts: I. Effect of alkali additives on catalytic activity and selectivity
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-20
    Athanasia Petala, Paraskevi Panagiotopoulou

    The effect of alkali promotion of TiO2 on the CO2 hydrogenation activity and selectivity has been investigated over 0.5%Ru/TiO2 and 5%Ru/TiO2 catalysts of different promoter type (Li, Na, K, Cs) and variable promoter loading (0.0–0.40 wt.%). The effect of alkali promotion was found to be more pronounced over catalysts of low Ru loading (or small Ru crystallites). In the case of 0.5%Ru/TiO2 catalysts, both catalytic activity and methane selectivity are strongly enhanced with the addition of small amounts (0.2 wt.%) of alkalis following the order of TiO2 (unpromoted) < Li ∼ K < Cs < Na. The intrinsic reaction rate exhibits a volcano-type dependence on the sodium content. Optimal results were obtained for 0.5%Ru/TiO2 catalyst containing 0.2 wt.% Na, the specific activity of which is about 3 times higher, compared to that of the unpromoted sample. In the case of 5%Ru/TiO2 catalysts, alkali addition does not practically affect catalytic activity and selectivity. Turnover frequency of 0.5%Ru/0.2%Na-TiO2 catalyst is higher than that measured over 5%Ru/TiO2, indicating that small amounts of alkalis can replace part of precious metals, reducing the cost and increasing the efficiency of the CO2 methanation process.

    更新日期:2017-11-20
  • Self-Assembled Synthesis of Defect-Engineered Graphitic Carbon Nitride Nanotubes for Efficient Conversion of Solar Energy
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-20
    Zhao Mo, Hui Xu, Zhigang Chen, Xiaojie She, Yanhua Song, Pengcheng Yan, Li Xu, Yucheng Lei, Shouqi Yuan, Huaming Li

    High-yield and uniform-size graphitic carbon nitride nanotubes (g-C3N4 nanotubes) with abundant nitrogen defects are synthesized for the first time, and just use melamine as a precursor, which embodies the concept of green, acid and alkali-free synthesis. And the morphology and performance are superior to the traditional molecular self-assembly (choose melamine and cyanuric acid as precursors), benefiting from melamine in situ turns into cyanuric acid and the release rate rather slowly. The g-C3N4 nanotubes show orderly morphology with length-diameter ratio of 30-70. The self-assembly of supramolecular intermediate is absolutely vital for the formation of g-C3N4 nanotubes with abundant nitrogen defects. A detailed process for the formation of defective g-C3N4 nanotubes is discussed. The g-C3N4 nanotubes exhibit excellent hydrogen evolution rate (118.5 μmol h−1), which is superior to the pure g-C3N4. The quantum efficiency of g-C3N4 nanotubes under irradiation at 420 nm is achieved to 6.8%, which is in the front rank of one dimension (1D) g-C3N4 structure, like g-C3N4 nanotubes, nanowires and nanorods. The improved photocatalytic performance benefits from the tubular structure and the nitrogen defects, which lead to the improved optical absorption, the more exposed active edges, the enhanced transfer and separation efficiency of the photogenerated electron-hole pairs, the higher surface area, fast and long-distance electron transport, the longer fluorescence lifetime and the nitrogen defects can act as the active sites. The g-C3N4 nanotubes also have broad applications in environmental treatement and photoelectrochemical detection of organic dyes. Additionally, the molecular self-assembled method can be a promising strategy for the shape-controlled synthesis of the other materials, like metal oxides and metal sulfides.

    更新日期:2017-11-20
  • Electrocatalytic Oxidation of Formaldehyde on Nanoporous Nickel Phosphate Modified Electrode
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-17
    A.H. Touny, Reham H. Tammam, M.M. Saleh

    Nanoporous nickel phosphate (nano-NiPh) is synthesized using a hydrothermal-based method from nickel phosphate precursors. It is applied for electrocatalytic oxidation of formaldehyde (FAL) in alkaline solution. The produced material is characterized using different techniques such as field emission scanning electron microscopy (FE-SEM), transmission electron micrograph (TEM) and X-ray diffraction (XRD) pattern. The nano-NiPh particles nearly reveal one-dimensional nanosize (200 × 800 nm) and demonstrate nanopores of ∼30 nm size. The chemical identity is found to be Ni3(PO4)2.8H2O. A nano-NiPh modified glassy carbon electrode (GC/nano-NiPh) is characterized by various techniques including cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS). The fabricated electrode demonstrates significant electrocatalytic activity towards the electrochemical oxidation of formaldehyde. The activity and stability of the electrode are discussed and some transport and kinetic parameters for FAL electrochemical oxidation have been determined.

    更新日期:2017-11-20
  • Influence of surface density on the CO2 photoreduction activity of a DC magnetron sputtered TiO2 catalyst
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-15
    F. Fresno, P. Reñones, E. Alfonso, C. Guillén, J.F. Trigo, J. Herrero, L. Collado, V.A. de la Peña O’Shea

    Advancing in the photocatalyst scale-up is crucial for the development of highly efficient solar fuels production at industrial scale. Here, we report DC-magnetron sputtering as a suitable technique to produce photocatalytic TiO2 coatings for CO2 reduction with a view on process scalability. The crystallinity of the obtained TiO2 coatings varies with surface density, with amorphous or quasi-amorphous coatings obtained with very low densities, while UV light absorption coefficients show the opposite trend, which has been related to the proportionally higher abuundace of surface defects and grain boundaries associated to the small crystal size and/or amorphicity of the lightest coatings. The as-prepared samples lead to the reduction of CO2 as demonstrated by 13C isotope tracing. An optimum catalyst area density of 1 g/m2 (by geometric area) is obtained in terms of CO2 photoreduction production, which is ascribed to a compromise situation between crystallinity and absorption coefficient. Selectivity to the different reaction products also varies with the coating characteristics, with amorphous or quasi-amorphous light coatings favouring methanol formation, in contrast with the preferred CO evolution in heavier, crystalline ones. Raman spectroscopy reveals the formation of peroxo and peroxocarbonate species on the photocatalyst surface as oxidation products during the CO2 reduction, the accummulation of which is proposed to be related to the observed catalyst deactivation.

    更新日期:2017-11-20
  • Direct synthesis of V-containing all-silica beta-zeolite for efficient one-pot, one-step conversion of carbohydrates into 2,5-diformylfuran
    Catal. Sci. Technol. (IF 5.773) Pub Date : 2017-11-07
    Wei Zhang, Wei Hou, Tongsuo Meng, Wenxia Zhuang, Jingyan Xie, Yu Zhou, Jun Wang
    更新日期:2017-11-20
  • Robust visible/near-infrared light driven hydrogen generation over Z-scheme conjugated polymer/CdS hybrid
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Xiaohu Zhang, Jie Xiao, Min Hou, Yonggang Xiang, Hao Chen

    Direct Z-scheme organic/inorganic semiconductor hybrid is seldom reported for photocatalytic H2 production from water splitting. Reported herein is a new type of organic/inorganic hybrid fabricated with modified conjugated polybenzothiadiazole (B-BT-1,4-E, noted as BE) flake and CdS nanorod. The internal Z-scheme electron transfer mechanism is evidenced by detecting the loading position of Pt through a in-situ photodeposition technique. It is found that the Z-scheme BE-CdS hybrid possesses broad visible/near-infrared (vis/NIR) light absorption region (400–700 nm) and rapid photogenerated e−/h+ separation rate. Photocatalytic performances reveal that the H2 production rate of optimal cocatalyst-free BE-CdS hybrid is 8.3 and 23.3 times higher than that of CdS and BE respectively, and a high apparent quantum yield (AQY) of 7.5% at 420 nm is obtained over the hybrid catalyst. This work opens new opportunities for exploiting highly efficient solar water splitting performances.

    更新日期:2017-11-20
  • Comparison of importance between separation efficiency and valence band position: The case of heterostructured Bi3O4Br/α-Bi2O3 photocatalysts
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Jian-guo Guo, Ying Liu, Ying-juan Hao, Yi-lei Li, Xiao-jing Wang, Rui-hong Liu, Fa-tang Li

    Heterostructured Bi3O4Br/α-Bi2O3 nanocomposites are prepared via in situ one-step self-combustion of ionic liquids. Tetrabutylammonium bromide (TBAB) is employed to be fuel, complexing agent for ionic liquids, as well as the reactant supplying Br for the objective material. The ratio of Bi3O4Br/α-Bi2O3 can be easily adjusted by controlling the amount of TBAB. The heterojunctions show higher photocatalytic ability towards both azo dye methyl orange (MO) and colorless pollutant phenol. The electron spin resonance (ESR) test and p-nitro blue tetrazolium chloride (NBT) degradation result indicate that generation amounts of superoxide anion radicals ( radical dot O2−) over heterojunctions are less than that over pure Bi3O4Br. Photoelectrochemical measurements show that separation efficiencies of photo-generated electrons and holes are decreased after the combination of Bi3O4Br and α-Bi2O3. Work function test and scavenger experiments display that holes play key role for pollutant degradation and the position of holes on α-Bi2O3 is lowered via hybridization. Thus, the enhanced photocatalytic activity over composites can be attributed to the position decline of α-Bi2O3 valence band, thus improving the reactivity of holes in direct oxidation of pollutants. In this case, valence band position is confirmed to be more important than separation efficiency of charge carriers in affecting photocatalytic performance.

    更新日期:2017-11-20
  • Constructing magnetic catalysts with in-suit solid-liquid interfacial photo-Fenton-like reaction over Ag3PO4@NiFe2O4 composites
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Shuquan Huanga, Yuanguo Xua, Ting Zhoua, Meng Xiea, Yun Maa, Qingqing Liua, Liquan Jinga, Hui Xua, Huaming Lia

    A high-performance photocatalyst should be superior not only in light absorption and charge transfer but also surface catalytic reaction. Here we report a green and simple strategy for evenly decorating Ag3PO4 particles using magnetic NiFe2O4 nanoparticles (NPs). The NiFe2O4 NPs could not only act as a magnetic support material for recycling the photocatalysts, but also in suit catalytically decompose the H2O2 produced on the surface of Ag3PO4 into O2 radical dot − and radical dot OH radicals via a photo-Fenton process. The catalytic decomposition of H2O2 could produce strong oxidative capacity O2 radical dot − and radical dot OH radicals for the organic pollutants degradation and reduce host semiconductor holes (h+(Ag3PO4)) consumption by the produced H2O2. Thus, the photocatalytic activities of Ag3PO4@NiFe2O4 composites were greatly enhanced. Taking the photocatalytic degradation of Methyl orange (MO), hardly decomposed colorless phenol compounds bisphenol A (BPA) and killing Escherichia coli (E. coli) as mode photocatalytic reactions, this system exhibited superior photocatalytic performances than that of pristine Ag3PO4. Electron spin resonance (ESR) spectroscopy and sacrificial-reagent incorporated photocatalytic characterizations indicated that the in suit eliminating/active decomposition of H2O2 produced by Ag3PO4 was the main reason for the enhanced photocatalytic activities.

    更新日期:2017-11-20
  • Formation of N2O Greenhouse Gas during SCR of NO with NH3 by Supported Vanadium Oxide Catalysts
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Minghui Zhu, Jun-Kun Lai, Israel E. Wachs

    Selective catalytic reduction of NO by NH3 over supported vanadium oxide catalysts has been studied for decades, but the studies mostly concentrated on the dominant N2 product with much less attention paid to the formation of the undesired N2O product. In the present study, fundamental aspects of the N2O formation reaction were elucidated by a series of temperature-programmed surface reaction studies with isotopic labeled reactants. The surface vanadium oxide species on the TiO2 support are active sites for the N2O formation reaction, while tungsten species mainly function as promoters. Oxygen from NO, gaseous O2 and catalyst oxygen all function as oxygen sources for formation of N2O (∼50%, ∼30% and ∼20%, respectively). The rate-determining-step for N2O formation involves breaking of the ammonia N single bond H bond. These new molecular level insights have the potential to guide the rational design of improved SCR catalysts for diesel engines with reduced N2O produced.

    更新日期:2017-11-20
  • Metal-free Thiolation of Imidazopyridines with Functionalized Haloalkanes Using Elemental Sulfur
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-19
    Jun-Rong Zhang, Ling-Zhi Zhan, Liang Wei, Yun-Yun Ning, Xiao-Lin Zhong, Jing-Xiong Lai, Li Xu, Ri-Yuan Tang

    The assembly of two functional molecules via a sulfur-linking atom allows for access to a diverse array of thioether-containing compounds. Herein, we disclose a metal-free thiolation of imidazopyridines with a variety of functionalized haloalkanes using elemental sulfur.

    更新日期:2017-11-20
  • 更新日期:2017-11-19
  • Copper-Catalyzed Dehydrative Cyclization of 1-(2-Hydroxyphenyl)-propargyl Alcohols with P(O)H Compounds for the Synthesis of 2-Phosphorylmethyl Benzofurans
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-18
    Ming Zhang, Jianlin Yang, Qing XU, Chao Dong, Li-Biao Han, Ruwei Shen

    A Cu(MeCN)4BF4-catalyzed dehydrative reaction of 1-(2-hydroxyphenyl)propargyl alcohols with diarylphosphine oxides has been developed to provide an efficient synthesis of phosphorylated benzofurans in good to high yields. In the presence of a catalytic amount of an organic base, a variety of H-phosphonates and H-phosphinates can also be employed as good substrates to produce the corresponding products in moderate yields. The reaction has significant economical and ecological advantages since the formation of a new Csp3−P bond and the benzofuran framwork could both be achieved using an inexpensive copper catalyst with water produced as the sole byproduct. The synthetic transformations of the product have also been demonstrated.

    更新日期:2017-11-19
  • Microwave-Assisted Synthesis of Benzimidazole-Linked Indoline and Indole Hybrids from C-2-Linked o-Amino Benzyl Benzimidazoles
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-18
    Yun-Ta Lee, Fengyu Chiu, Indrajeet Barve, Chung-Ming Sun

    An efficient and novel synthesis of benzimidazole-linked indoline hybrids via an unconventional Pictet-Spengler type condensation of C-2 linked o-aminobenzyl benzimidazole with aldehydes and ketones under microwave irradiation is explored. The key condensation step consists of acid catalyzed imine generation followed by intramolecular C-C bond formation through unique reactivity of benzimidazole moiety. The scope of this method is further extended to synthesize tetracyclic pyrrolo indole benzoimidazole carboxylates through 2-carboxyaldehydes.

    更新日期:2017-11-19
  • Intermolecular Rhodium(II)-Catalyzed Allylic C(sp3)-H Amination of Cyclic Enamides
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-18
    Isabelle Gillaizeau, Philippe Dauban, Gregory jestin, Romain Rey-Rodriguez, pascal retailleau, Benjamin Darses

    The intermolecular Rh(II)-catalyzed C(sp3)–H amination of enamides gives access to new 4-aminopiperidine derivatives that are useful building blocks in medicinal chemistry. This efficient transformation proceeds at room temperature with complete regio- and chemoselectivity in favor of the allylic C(sp3)–H bond, and has a broad functional group tolerance. In addition, the matched combination of the chiral Rh2(S-nta)4 (nta = (S)-N-1,8-naphthoylalanine) with an optically pure (S)-sulfonimidamide allows isolation of allylic amines with excellent stereocontrol.

    更新日期:2017-11-19
  • Copper/Iron-Cocatalyzed Cascade Perfluoroalkylation/Cyclization of 1,6-Enynes with Iodoperfluoroalkanes
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-18
    Xiao-Feng Xia, Jipan Yu, Dawei Wang

    A copper/iron-cocatalyzed fluoroalkylative cyclization of 1,6-enynes with readily available iodoperfluoroalkanes reagents for the synthesis of the corresponding fluoroalkylated pyrrolidines and benzofuran derivatives is reported. This novel protocol provides a mild method for the construction of Csp3-CF2 and exocyclic double bonds in one step with high regio- and stereo-selectivities.

    更新日期:2017-11-19
  • Importance of Ag–Cu Biphasic Boundaries for Selective Electrochemical Reduction of CO2 to Ethanol
    ACS Catal. (IF 10.614) Pub Date : 2017-11-17
    Seunghwa Lee, Gibeom Park, Jaeyoung Lee
    更新日期:2017-11-19
  • Mechanistic Insights for Low-Overpotential Electroreduction of CO2 to CO on Copper Nanowires
    ACS Catal. (IF 10.614) Pub Date : 2017-11-17
    Liang Cao, David Raciti, Chenyang Li, Kenneth J. T. Livi, Paul F. Rottmann, Kevin J. Hemker, Tim Mueller, Chao Wang
    更新日期:2017-11-19
  • Utilization of CO2 as a C1 Building Block in a Tandem Asymmetric A3 Coupling-Carboxylative Cyclization Sequence to 2-Oxazolidinones
    ACS Catal. (IF 10.614) Pub Date : 2017-11-17
    Xiao-Tong Gao, Chen-Chen Gan, Si-Yue Liu, Feng Zhou, Hai-Hong Wu, Jian Zhou
    更新日期:2017-11-19
  • Novel β-NiS film modified CdS nanoflowers heterostructure nanocomposite: extraordinarily highly efficient photocatalysts for hydrogen evolution
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Yu Zhang, Zhijian Peng, Shundong Guan, Xiuli Fu

    The compositing of semiconductor based photocatalysts with cocatalysts is a well-known, effective strategy to acquire high hydrogen evolution efficiency, for which their morphology and composition are the concerns of most literatures. However, the contact between them, which has been always difficult to improve, is also a key factor. Here a novel β-NiS film modified CdS nanoflowers (NiS/CdS NFs) heterostructure nanocomposite (HSNC) was successfully synthesized through a simple one-pot hydrothermal method. The obtained NiS/CdS NFs HSNC has well-constructed integrated structure of strong adhesion between the semiconducting CdS NFs and the cocatalyst NiS thin films, displaying good transfer ability to photogenerated electrons and high adsorption to visible light together. Resultantly, the obtained composite presents extraordinarily highly efficient photocatalytic hydrogen evolution, and high chemical and structural stability in aqueous solution containing 20 vol.% lactic acid under visible light. The highest rate for hydrogen production reached a recorded value of about 30.1 mmol h−1 g−1 at 25 °C among all CdS-NiS composite catalysts, and the highest apparent quantum efficiency was approximately 43% at 420 nm. The growth and photocatalysis mechanisms for the NiS/CdS NFs were proposed.

    更新日期:2017-11-17
  • Structural and Electronic Properties of Oxygen Defective and Se-Doped p-Type BiVO4(001) Thin Film for the Applications of Photocatalysis
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Habib Ullah, Asif A. Tahir, Tapas K. Mallick

    Monoclinic BiVO4 is being used as a photocatalyst due to its stability, cost-effectiveness, ease of synthesis, and narrow band gap. Although, the valence band maximum, VBM (∼ −6.80 eV vs vacuum) of BiVO4 is well below the redox potential of water but having less positive conduction band minimum, CBM (-4.56 eV vs vacuum), responsible for its low efficiency. We have carried out a comprehensive periodic density functional theory (DFT) simulations for the pristine, Oxygen defective (Ov) and Se doped BiVO4, to engineer not only its CB edge position but the overall photocatalytic and charge carrier properties. Our theoretical method has nicely reproduced the experimental data of pristine BiVO4, which encouraged us to elaborate further its Ov and Se-doped characteristics. It is found that both the Ov (1% Oxygen vacancy) and Se-doped BiVO4 (1 to 2% Se) have ideal band edges, band gaps, and small effective masses of electrons and holes, responsible for high photocatalytic activities. Moreover, Se-doped BiVO4 behave as p-type semiconductor. Finally, the photocatalytic water-splitting behaviour of the selected surfaces were counterchecked with water interaction, where the strong water adsorption energy of about ∼-38 to −50 kcal/mol, confirms and predicts their higher efficiencies compared to that of parent BiVO4.

    更新日期:2017-11-17
  • Alkali-assisted fabrication of holey carbon nitride nanosheet with tunable conjugated system for efficient visible-light-driven water splitting
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Ting Song, Piyong Zhang, Tingting Wang, Atif Ali, Heping Zeng

    Graphitic carbon nitride (CN) nanosheets have aroused a great deal of interest due to their capability to utilize visible light to split water into its constituent molecules of hydrogen and oxygen (H2 and O2). However, the photocatalytic capacity of conventional bulk g-C3N4, with its large π-π conjugated electronic system, is still constrained by the π-π stacking interaction and small number of active sites. Hence, an uncomplicated post-processing method to construct a different π-π conjugated electronic system of holey CN nanosheets using alkali etching of bulk CN (CN (B)) at 300 °C for 1 h has been developed. Among such compounds, the optimal alkali treatment bulk CN (CN 3(2)) exhibits a suitable conjugated system and copious in-plane holes, and it retains the ability to absorb sunlight during alkali depolymerization. Compared to CN (B), the resultant CN 3(2) has a distensible bandgap of 2.66 eV associated with a much larger specific surface area of 265.2 m2 g−1. However, excessive alkali treatment significantly decrease the visible light absorbance and the photocatalytic properties of the CN nanosheet, which demonstrated that a suitable π-π conjugated electronic system is very important in allowing the process to proceed. As such, the photocatalytic H2 and O2 production rate of CN 3(2) was nearly 24.6 times that of CN (B) with the addition of carbon quantum dots (CQDs) and Pt.

    更新日期:2017-11-17
  • High efficiency water splitting photoanodes composed of nano-structured anatase-rutile TiO2 heterojunctions by pulsed-pressure MOCVD
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Aleksandra J. Gardecka, Catherine Bishop, Darryl Lee, Sacha Corby, Ivan P. Parkin, Andreas Kafizas, Susan Krumdieck

    In this article, thin solid films are processed via pulsed-pressure metal organic chemical vapour deposition (PP-MOCVD) on FTO substrates over a range of processing times to produce a range of thicknesses and microstructures. The films are highly nanostructured anatase-rutile TiO2 composite films with unique single crystal dendrites. After annealing, carbon was removed, and materials showed improved water splitting activity; with IPCEs above 80% in the UV, photocurrents of ∼1.2 mA.cm−2 at 1.23 VRHE at 1 sun irradiance and an extension of photoactivity into the visible range. The annealed material exhibits minimal recombination losses and IPCEs amongst the highest reported in the literature; attributed to the formation of a high surface area nanostructured material and synergetic interactions between the anatase and rutile phases.

    更新日期:2017-11-17
  • A novel route combined precursor-hydrothermal pretreatment with microwave heating for preparing holey g-C3N4 nanosheets with high crystalline quality and extended visible light absorption
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-15
    Qiong Liu, Xueli Wang, Qian Yang, Zhengguo Zhang, Xiaoming Fang

    The photocatalytic water splitting for hydrogen fuel by utilizing solar energy is considered a useful route to settle the energy crisis, but a bottleneck is occurred in developing a highly efficient photocatalysts. Herein, a facile method is applied to fabricate the holey carbon nitride (HCN) nanosheets with high crystallization network and extended optical absorption region by using the hydrothermal and microwave processes. The hydrothermal treatment of dicyandiamide will enable it to transform into the melamine-cyanaurate complex which would then form the ultrathin CN nanosheets with the abundant porous structure. And then the microwave-assisted thermolysis process helps the generation of g-C3N4 which retains the highly crystalline and the enhanced optical absorption region. Eventually, the highly crystalline network comes with the narrowed band gap and the higher specific surface area encounter in optimized g-C3N4 leading it exhibits a relatively high photocatalytic performance than pristine bulk carbon nitride which the hydrogen evolution rate of it reaching 81.6 μmol/h.

    更新日期:2017-11-17
  • Cobalt Manganese Spinel as an Effective Cocatalyst for Photocatalytic Water Oxidation
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-15
    Linzhu zhang, Can Yang, Zailai Xie, Xinchen Wang

    Efficient co-catalysts are crucial for photocatalytic water oxidation towards conversion of solar energy into chemical energy. Herein, we develop a sustainable and effective water oxidation system using graphitic carbon nitride (g-C3N4) and cubic cobalt manganese spinel (c-CoMn2O4) as light transducer and water oxidation co-catalyst, respectively. The surface modified g-C3N4 with c-CoMn2O4 not only accelerates the interface transfer rate of charge carriers but also reduces the excessive energy barrier for O-O formation, leading to an enhanced photocatalytic activity of water oxidation. Benefiting from the well surface engineering of g-C3N4, the g-C3N4-CoMn2O4 (CN-CM) composites exhibit an enhanced performance of photocatalytic water oxidation. The oxygen evolution rate (OER) of CN-CM is 4 times higher than that of pristine g-C3N4. It is a highly active in oxidation of water, with an apparent quantum yield (AQY) of ca. 1% at 380 nm with AgNO3 as sacrificial agent. This improvement is mainly due to the mixed-valence Co and Mn cations contained in c-CoMn2O4 spinel.

    更新日期:2017-11-17
  • Isothermic adsorption of morin onto the reducible mesoporous manganese oxide materials surface
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-15
    Ali K. Ilunga, Itumeleng R. Legodi, Simbongile Gumbi, Reinout Meijboom

    A series of mesoporous manganese oxide materials were synthesized following the inverse micelle sol-gel method and categorized by the heat treatment. The tunable features and crystallinity of the mesoporous materials were analyzed by BET and XRD analyses. The HR-TEM and TRP analyses were conducted to analyze the meso-ordered structure and reducibility of the mesoporous manganese oxide materials. The catalytic activity of the mesoporous materials was investigated in aerobic oxidation of morin as a model reaction. The experimental data were interpreted according to the Mars-van Krevelen and Langmuir-Hinshelwood approach. The heat treatment influenced the crystallite size and the activity of the mesoporous manganese oxide materials. The activity of the lattice oxygen was a critical factor in the aerobic process. MnO2–350 °C exhibited the largest lattice oxygen activity ((64.3 ± 5.6) × kJ mol−1 m−2).

    更新日期:2017-11-17
  • Homogeneous Introduction of CeOy into MnOx-based Catalyst for Oxidation of Aromatic VOCs
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-15
    Jin Chen, Xi Chen, Xi Chen, Wenjian Xu, Zhen Xu, Hongpeng Jia, Jing Chen

    3MnOx-1CeOy (3Mn1Ce), a binary oxide with stoichiometric ratio of Mn/Ce = 3, is synthesized via hydrolysis driving redox. Compared to MnO2, CeO2, Cop-3Mn1Ce and Mixed-3Mn1Ce, the 3Mn1Ce catalyst exhibits better catalytic activity for toluene oxidation, which could be ascribed to higher concentration of active lattice oxygen, and better low-temperature reducibility, as well as homogeneous dispersion. In the test of substrate applicability, 3Mn1Ce displays good performances in the removal of benzene, o-xylene and chlorobenzene at moderate temperature. The application of high WHSV of 240000 mL/(g h) confirms the 3Mn1Ce catalyst still remains high efficiency to diminish toluene, giving the temperature at 280 °C for complete mineralization. A set of experiments under simulated realistic exhaust conditions demonstrate that 3Mn1Ce is a robust catalyst with high activity to oxidize mixed aromatic VOCs (BTX and chlorobenzene), satisfied endurability to high humidity (above 10 − 20 vol.% water) and good tolerance to severe change of reaction temperature. With characterization of XRD and TPR, the high performance is related to the homogeneous introduction of Ce resulting in higher structural stability and reversible reducibility. Moreover, the inner principle for oxidation of VOCs is revealed by comprehension of kinetic study.

    更新日期:2017-11-17
  • One Pot Synthesis of γ-Benzopyranones via Iron-Catalyzed Aerobic Oxidation and Subsequent 4-Dimethylaminopyridine Catalyzed 6-endo Cyclization
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-17
    Di Zhai, Lingzhu Chen, Minqiang Jia, Shengming Ma
    更新日期:2017-11-17
  • Triflic Acid as an Efficient Brønsted Acid Promoter for the Umpolung of N-Ac Indoles in Hydroarylation Reactions
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-17
    Raj Kumar Nandi, Alejandro Perez-Luna, Didier Gori, Rodolphe Beaud, Régis Guillot, Cyrille Kouklovsky, Vincent Gandon, Guillaume Vincent
    更新日期:2017-11-17
  • Electroanalysis in 2D-TiO2 Nanosheet Hosts: Electrolyte and Selectivity Effects in Ferroceneboronic Acid – Saccharide Binding
    Electroanalysis (IF 2.851) Pub Date : 2017-11-17
    Wulan Tri Wahyuni, Budi Riza Putra, Christian Harito, Dmitry V. Bavykin, Frank C. Walsh, Tony D. James, Gabriele Kociok-Köhn, Frank Marken
    更新日期:2017-11-17
  • Zeolitic Materials for DeNOx Selective Catalytic Reduction
    ChemCatChem (IF 4.803) Pub Date : 2017-11-17
    Ying Xin, Qian Li, Zhaoliang Zhang
    更新日期:2017-11-17
  • Amphiphilic Mesoporous Poly(Ionic Liquid) Immobilized Heteropolyanions Towards the Efficient Heterogeneous Epoxidation of Alkenes with Stoichiometric Hydrogen Peroxide
    ChemCatChem (IF 4.803) Pub Date : 2017-11-17
    Yuming Shi, Zengjing Guo, Qian Wang, Lingyu Zhang, Jing Li, Yu Zhou, Jun Wang
    更新日期:2017-11-17
  • Using data mining technology in screening potential additives to Ni/Al2O3 catalysts for methanation
    Catal. Sci. Technol. (IF 5.773) Pub Date : 2017-11-07
    Xiaoxia Han, Chaofan Zhao, Haixia Li, Shusen Liu, Yahong Han, Zhilei Zhang, Jun Ren
    更新日期:2017-11-17
  • Mechanisms of metal-catalyzed cycloisomerizations of o-propargylbiaryls and o-allenylbiaryls to phenanthrenes: a DFT study
    Catal. Sci. Technol. (IF 5.773) Pub Date : 2017-11-07
    Mengistu Gemech Menkir, Shyi-Long Lee
    更新日期:2017-11-17
  • Potassium 2-oxo-3-enoates as Effective and Versatile Surrogates for α, β-Unsaturated Aldehydes in NHC-Catalyzed Asymmetric Reactions
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-16
    Yaru Gao, Yafei Ma, Chen Xu, Lin Li, Tianjian Yang, Guoqing Sima, Zhenqian Fu, Wei Huang

    Potassium 2-oxo-3-enoates, which are readily prepared at scale and easily stored, have been found to be effective and versatile surrogates for α,β-unsaturated aldehydes in NHC-catalyzed asymmetric reactions. Promoted by chiral N-heterocyclic carbenes combined with LiCl, these easy-to-handle solid salts could release of CO2 and then undergo asymmetric reactions via homoenolate and α,β-unsaturated acyl azolium intermediate. The reactions have broad substrate scopes with high enantioselectivities.

    更新日期:2017-11-17
  • Manufacture of Citronellal by Rhodium Catalysed Homogeneous Hydrogenation of Neral
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-16
    Armin Boerner, Stephan Doerfelt, Jens Holz

    The highly chemoselective hydrogenation of neral affording citronellal is described. The reaction has been conducted with homogeneous rhodium complexes. Among a set of ancillary diphosphane ligands tested Xantphos was found to be superior. The relevant precatalyst has been generated from neutral metal sources such as Rh(acac)(CO)2 or the carbon monoxide free rhodium source Rh(acac)(cod) in the absence of any base. High activity and chemoselectivity in favour of the desired citronellal is achieved at 0.1 MPa and room temperature. Under the same conditions also geranial is reduced to citronellal. The addition of carbon monoxide to the hydrogen stream as used in an industrial process is not necessary.

    更新日期:2017-11-17
  • Heteroatom-Doped Carbonaceous Photocatalysts for Solar Fuel Production and Environmental Remediation
    ChemCatChem (IF 4.803) Pub Date : 2017-11-16
    Zhongkui Zhao, Guifang Ge, Di Zhang
    更新日期:2017-11-17
  • Metal-Free Reduction of Phosphine Oxides, Sulfoxides, and N-Oxides with Hydrosilanes using a Borinic Acid Precatalyst
    ChemCatChem (IF 4.803) Pub Date : 2017-11-16
    Aurélien Chardon, Orianne Maubert, Jacques Rouden, Jérôme Blanchet
    更新日期:2017-11-17
  • Photocatalytic CO2 Reduction under Continuous Flow High-Purity Conditions: Influence of Light Intensity and H2O Concentration
    ChemCatChem (IF 4.803) Pub Date : 2017-11-16
    Martin Dilla, Alina Mateblowski, Simon Ristig, Jennifer Strunk
    更新日期:2017-11-17
  • High Performance Diesel Oxidation Catalysts using Ultra-low Pt Loading on Titania Nanowire Array integrated Cordierite Honeycombs
    Catal. Today (IF 4.636) Pub Date : 2017-11-15
    Son Hoang, Xingxu Lu, Wenxiang Tang, Sibo Wang, Shoucheng Du, Chang-Yong Nam, Yong Ding, Rodrigo D. Vinluan III, Jie Zheng, Pu-Xian Gao

    High performance of an ultra-low Pt loading diesel oxidation catalyst can be achieved by using a combination of novel nano-array structured support, precise control of ultrafine active Pt particles, and an addition of H2 as a promoter into the exhausts. Highly stable mesoporous rutile TiO2 nano-array was uniformly grown on three-dimensional (3-D) cordierite honeycomb monoliths using a solvothermal synthesis. Atomic layer deposition was employed for precise dispersion of ultrafine Pt particles (0.95 ± 0.24 nm) on TiO2 nano-array with a Pt loading of 1.1 g/ft3. Despite low Pt loading, the Pt/TiO2 nano-array catalyst shows impressive low-temperature oxidation reactivity, with the conversion of CO and total hydrocarbon (THC) reaching 50% at 224 and 285 °C, respectively, in the clean diesel combustion (CDC) simulated exhaust conditions. The excellent activity is attributed to the unique nano-array structure that promotes gas-solid interaction and ultra-small Pt particle dispersion that increase surface Pt atoms. We also demonstrate that addition of more H2 into the exhaust can lower light-off temperature for CO and THC by up to ∼60 °C and ∼30 °C, respectively.

    更新日期:2017-11-16
  • Computational and experimental study of the second metal effect on the structure and properties of bi-metallic MeMoS-sites in transition metal sulfide catalysts
    Catal. Today (IF 4.636) Pub Date : 2017-11-14
    E.A. Permyakov, V.S. Dorokhov, V.V. Maximov, P.A. Nikulshin, A.A. Pimerzin, V.M. Kogan

    Bimetallic (Me)MoS2 (Me = Nb, Fe, Co, Ni) sulfide systems, both modified and non-modified by potassium, were investigated by the DFT method. Geometric and electronic structures of active sites were compared in terms of CO and hydride hydrogen adsorption. Most of the studied metals are electron density acceptors on the S-edge of the crystallite, which inhibits hydride hydrogen adsorption and deactivates the S-edge. The CO adsorption energy on the Me-edge decreased in the order Fe > Co > Ni. Computational data were verified by experimental tests in syngas conversion. Modification by potassium was shown to hinder σ-bonding of the adsorbed molecule and to stabilize hydride hydrogen.

    更新日期:2017-11-16
  • Organocatalytic Asymmetric Synthesis of Six-Membered Carbocycle-Based Spiro Compounds
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-16
    Xin Xie, Wei Huang, Cheng Peng, Bo Han
    更新日期:2017-11-16
  • Enzyme-Catalysed Synthesis of Cyclohex-2-en-1-one cis-Diols from Substituted Phenols, Anilines and Derived 4-Hydroxycyclohex-2-en-1-ones
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-16
    Derek R. Boyd, Narain D. Sharma, Peter B. A. McIntyre, Paul J. Stevenson, W. Colin McRoberts, Amit Gohil, Patrick Hoering, Christopher C. R. Allen
    更新日期:2017-11-16
  • Asymmetric Hydrolytic and Aminolytic Kinetic Resolution of Racemic Epoxides using Recyclable Macrocyclic Chiral Cobalt(III) Salen Complexes
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-16
    Rajkumar Tak, Manish Kumar, Tusharkumar Menapara, Naveen Gupta, Rukhsana I. Kureshy, Noor-ul H. Khan, E. Suresh
    更新日期:2017-11-16
  • Photocatalytic Oxidative Bromination of Electron-Rich Arenes and Heteroarenes by Anthraquinone
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-16
    Daniel Petzold, Burkhard König
    更新日期:2017-11-16
  • Three-Component Coupling Reactions of Maleimides, Thiols, and Amines: One-Step Construction of 3,4-Heteroatom-functionalized Maleimides by Copper-Catalyzed C(sp2)−H Thioamination
    Adv. Synth. Catal. (IF 5.646) Pub Date : 2017-11-16
    Zhen-Hua Yang, Hong-Ru Tan, Yu-Long An, Yu-Wei Zhao, Hao-Peng Lin, Sheng-Yin Zhao
    更新日期:2017-11-16
  • The Hybrid of Gold Nanoparticles and 3D Flower-like MnO2 Nanostructure with Enhanced Activity for Detection of Hydrogen Peroxide
    Electroanalysis (IF 2.851) Pub Date : 2017-11-16
    Qinglin Sheng, Xiujuan Qiao, Jianbin Zheng
    更新日期:2017-11-16
  • Electrocatalytic Oxidation of Carbohydrates Mediated by Nitroxyl Radical-Modified Electrodes in Aqueous Solution
    Electroanalysis (IF 2.851) Pub Date : 2017-11-16
    Tetsuya Ono, Katsuhiko Sato, Syunki Shimizu, Kentaro Yoshida, Takenori Dairaku, Yasuhiro Suzuki, Yoshitomo Kashiwagi
    更新日期:2017-11-16
  • 更新日期:2017-11-16
  • Photocatalytic reduction of CO2 with H2O vapor under visible light over Ce doped ZnFe2O4
    Catal. Sci. Technol. (IF 5.773) Pub Date : 2017-11-07
    Jiajia Guo, Kang Wang, Xitao Wang
    更新日期:2017-11-16
  • Sub-nano MgF2 embedded in carbon nanofibers and electrospun MgF2 nanofibers by one-step electrospinning as highly efficient catalysts for 1,1,1-trifluoroethane dehydrofluorination
    Catal. Sci. Technol. (IF 5.773) Pub Date : 2017-11-06
    Wenfeng Han, Chunpeng Zhang, Haili Wang, Shenglan Zhou, Haodong Tang, Luteng Yang, Zhikun Wang
    更新日期:2017-11-16
  • Carbon nanofibres-supported KCoMo catalysts for syngas conversion into higher alcohols
    Catal. Sci. Technol. (IF 5.773) Pub Date : 2017-11-06
    Ho Ting Luk, Tim Forster, Cecilia Mondelli, Sebastian Siol, Daniel Curulla-Ferré, Joseph A. Stewart, Javier Pérez-Ramírez
    更新日期:2017-11-16
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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