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Chinese Journal of Catalysis
2018, Vol. 39, No. 6
Online: 18 June 2018


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Prof. Yingwei Li and coworkers in their article on page 1017–1026 reported an efficient mimicry to the oxygen-evolving complex in photosystem II and discussed the promotion effect of brushite in water oxidation reaction. Brushite could be deposited on the zinc-manganese oxide catalyst simultaneously with the photocatalytic water oxidation reaction in the neutral phosphate-buffered aqueous solution containing [Ru(bpy)₃]²⁺-Na₂S₂O₈ and Ca²⁺, and is responsible for the largely enhanced water oxidation performance.

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Table of Contents for VOL.39 No.6 2018, 39 (6):  0-0.  Abstract ( 136 )   PDF (1464KB) ( 435 )

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Chemical transformation of sugars into amino acids Tao Zhang 2018, 39 (6):  1013-1016.  DOI: 10.1016/S1872-2067(18)63093-1 Abstract ( 483 )   [Full Text(HTML)] () PDF (713KB) ( 818 )

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In situ doping brushite on zinc manganese oxide toward enhanced water oxidation performance: Mimicry of an oxygen-evolving complex Miao Jiang, Junying Chen, Yingwei Li 2018, 39 (6):  1017-1026.  DOI: 10.1016/S1872-2067(18)63075-X Abstract ( 347 )   [Full Text(HTML)] () PDF (1279KB) ( 825 )   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 O2evolution 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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Pt/Nb-WOx for the chemoselective hydrogenolysis of glycerol to 1,3-propanediol: Nb dopant pacifying the over-reduction of WOx supports Man Yang, Xiaochen Zhao, Yujing Ren, Jia Wang, Nian Lei, Aiqin Wang, Tao Zhang 2018, 39 (6):  1027-1037.  DOI: 10.1016/S1872-2067(18)63074-8 Abstract ( 404 )   [Full Text(HTML)] () PDF (1482KB) ( 1165 )   Supporting Information 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 WOx and prepared 1D needle-, 2D flake-, and 3D sphere-stack mesoporous structured Nb-WOx 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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N-doped carbon modified Pt/CNTs synthesized by atomic layer deposition with enhanced activity and stability for methanol electrooxidation Huimin Yang, Baiyan Zhang, Bin Zhang, Zhe Gao, Yong Qin 2018, 39 (6):  1038-1043.  DOI: 10.1016/S1872-2067(18)63066-9 Abstract ( 374 )   [Full Text(HTML)] () PDF (632KB) ( 910 )   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℃ 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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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 Hojat Veisi, Ahmad Nikseresht, Shahin Mohammadi, Saba Hemmati 2018, 39 (6):  1044-1050.  DOI: 10.1016/S1872-2067(18)63049-9 Abstract ( 331 )   [Full Text(HTML)] () PDF (781KB) ( 659 )   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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Preparation of a fullerene[60]-iron oxide complex for the photo-fenton degradation of organic contaminants under visible-light irradiation Cong-yang Zou, Ze-da Meng, Wen-chao Ji, Shou-qing Liu, Zhemin Shen, Yuan Zhang, Ni-shan Jiang 2018, 39 (6):  1051-1059.  DOI: 10.1016/S1872-2067(18)63067-0 Abstract ( 269 )   [Full Text(HTML)] () PDF (1871KB) ( 714 )   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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Acid-promoted Ir-La-S/AC-catalyzed methanol carbonylation on single atomic active sites Zhou Ren, Yuan Lyu, Siquan Feng, Xiangen Song, Yunjie Ding 2018, 39 (6):  1060-1069.  DOI: 10.1016/S1872-2067(18)63019-0 Abstract ( 314 )   [Full Text(HTML)] () PDF (1114KB) ( 839 )   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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Hydrogenation of 2-ethylanthraquinone with bimetallic monolithic catalysts: An experimental and DFT study Yanyan Guo, Chengna Dai, Zhigang Lei 2018, 39 (6):  1070-1080.  DOI: 10.1016/S1872-2067(18)63035-9 Abstract ( 350 )   [Full Text(HTML)] () PDF (1792KB) ( 986 )   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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Green catalytic oxidation of benzyl alcohol over Pt/ZnO in base-free aqueous medium at room temperature Juanjuan Liu, Shihui Zou, Jiachao Wu, Hisayoshi Kobayashi, Hongting Zhao, Jie Fan 2018, 39 (6):  1081-1089.  DOI: 10.1016/S1872-2067(18)63022-0 Abstract ( 545 )   [Full Text(HTML)] () PDF (1245KB) ( 1284 )   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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Preparation of N-vacancy-doped g-C3N4 with outstanding photocatalytic H2O2 production ability by dielectric barrier discharge plasma treatment Xuhe Li, Jian Zhang, Feng Zhou, Hongliang Zhang, Jin Bai, Yanjuan Wang, Haiyan Wang 2018, 39 (6):  1090-1098.  DOI: 10.1016/S1872-2067(18)63046-3 Abstract ( 303 )   [Full Text(HTML)] () PDF (924KB) ( 1029 )   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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Preparation and catalytic properties of mesoporous nV-MCM-41 for propane oxidative dehydrogenation in the presence of CO2 Zai-Fang Han, Xu-Liang Xue, Jian-Min Wu, Wan-Zhong Lang, Ya-Jun Guo 2018, 39 (6):  1099-1109.  DOI: 10.1016/S1872-2067(18)63048-7 Abstract ( 324 )   [Full Text(HTML)] () PDF (1217KB) ( 817 )   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 CO2on the oxidative dehydrogenation of ODHP was demonstrated as the reaction coupling mechanism and "lattice oxygen" mechanism.

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Olefin oligomerization via new and efficient Brönsted acidic ionic liquid catalyst systems Guoqin Wang, Heyuan Song, Ruiyun Li, Zhen Li, Jing Chen 2018, 39 (6):  1110-1120.  DOI: 10.1016/S1872-2067(18)63071-2 Abstract ( 322 )   [Full Text(HTML)] () PDF (580KB) ( 681 )   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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Glycerol hydrogenolysis to n-propanol over Zr-Al composite oxide-supported Pt catalysts Chuang Li, Bo He, Yu Ling, Chi-Wing Tsang, Changhai Liang 2018, 39 (6):  1121-1128.  DOI: 10.1016/S1872-2067(18)63068-2 Abstract ( 381 )   [Full Text(HTML)] () PDF (860KB) ( 890 )   Zr-Al mixed oxide supported Pt catalysts with different Zr/Al mole ratios (2.5%Pt/ZrxAl1-xOy) 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/Zr0.7Al0.3Oy exhibited excellent selectivity for n-propanol with 81.2% glycerol conversion at 240℃ 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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One-step aldol condensation reaction of dimethoxymethane and methyl acetate over supported Cs/ZSM-35 zeolite catalysts Zhanling Ma, Xiangang Ma, Hongchao Liu, Wenliang Zhu, Xinwen Guo, ZhongminLiu 2018, 39 (6):  1129-1137.  DOI: 10.1016/S1872-2067(18)63069-4 Abstract ( 341 )   [Full Text(HTML)] () PDF (580KB) ( 891 )   Supporting Information 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.

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Simple synthesis of nitrogen-doped carbon spheres as a highly efficient metal-free electrocatalyst for the oxygen reduction reaction Jinhui Tong, Wenyan Li, Lili Bo, Wenhui Wang, Yuliang Li, Tao Li, Qi Zhang, Haiyan Fan 2018, 39 (6):  1138-1145.  DOI: 10.1016/S1872-2067(18)63078-5 Abstract ( 356 )   [Full Text(HTML)] () PDF (835KB) ( 938 )   Supporting Information 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.