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Chinese Journal of Catalysis
2013, Vol. 34, No. 2
Online: 05 February 2013


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The properties of cobalt and oxygen ions in Co₃O₄ are just the two sides of the same coin. Using controlled synthesis of nano materials, Co₃O₄ enriched with surface Co³⁺ cations can be created, giving excellent catalytic performance. On the other hand, Yu and coworkers in their Article on pages 283–293 reported that pretreatment under suitable conditions favored the formation of oxygen vacancy clusters on the Co₃O₄ surface, the presence of which guarantees CO oxidation at low temperatures.

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Table of Contents for Vol. 34 No. 2 2013, 34 (2):  0-0.  Abstract ( 612 )   PDF (996KB) ( 629 )

Research papers

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Influence of calcination and pretreatment conditions on the activity of Co3O4 for CO oxidation YU Yun-Bo, ZHAO Jiao-Jiao, HAN Xue, ZHANG Yan, QIN Xiu-Bo, WANG Bao-Yi 2013, 34 (2):  283-293.  DOI: 10.1016/S1872-2067(11)60484-1 Abstract ( 1095 )   [Full Text(HTML)] () PDF (818KB) ( 1311 )   The influence of calcination and pretreatment conditions on the structure of Co3O4 and its activity for CO oxidation were studied. TG analysis indicated that the precursor of Co3O4 prepared by a precipitation method was present in the form of cobalt hydroxide carbonate, calcination of which within the temperature range of 150–400 oC in air resulted in the formation of cubic phase Co3O4. N2 adsorption-desorption, powder X-ray diffraction, transmission electron microscopy, and activity test results showed that the prepared Co3O4 samples were comprised of nanoparticles, with the specific surface area and size distribution closely related to the calcination temperature. Over these samples, a size dependence of the catalytic activity for CO oxidation was clearly observed. As identified by positron annihilation lifetime spectrum, low temperature oxygen temperature-programmed desorption, and durability testing for CO oxidation, pretreatment of Co3O4 in N2 within the temperature range 150–250 oC favors the formation of surface oxygen vacancy clusters, the occurrence of which would be beneficial for the adsorption and activation of O2, and also for the catalytic oxidation of CO. Meanwhile, the reconstruction of oxygen vacancies on the surface of Co3O4, induced by the pretreatment process, was also discussed.

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Effects of crystallinity of ZSM-5 zeolite on para-selective tert-butylation of ethylbenzene PUSHPARAJ Hemalatha, MANI Ganesh, MUTHIAHPILLAI Palanichamy, VELAYUTHAM Murugesan, PARK Yong-Ki, CHOI Won Choon, JANG Hyun Tae 2013, 34 (2):  294-304.  DOI: 10.1016/S1872-2067(11)60482-8 Abstract ( 908 )   [Full Text(HTML)] () PDF (936KB) ( 1097 )   Highly crystalline ZSM-5 zeolites are important for para-selective alkylation of alkyl aromatics, because they carry few external acid sites for isomerization of p-dialkyl products. Such zeolites (Si/Al = 25, 50, and 75) were synthesized in a fluoride medium between pH 4 and 6. Their crystallinities, crystal sizes, and surface areas were higher than those of a commercial ZSM-5 zeolite. Their para selectivities in alkylation were tested for vapor-phase tert-butylation of ethylbenzene between 200 and 400 °C. As expected, all the catalysts showed more than 90% para selectivity. At 300 °C, ethylbenzene conversion decreased in the order ZSM-5(25, commercial) > ZSM-5(25) > ZSM-5(50) > ZSM-5(75). The catalysts had weak, medium, and strong acid sites, but all the acid sites of ZSM-5(75) were weaker than those of ZSM-5(25) and ZSM-5(50). The high activity of commercial ZSM-5 was caused by its strong acid sites being stronger than those of the synthesized zeolites. Although the activity of the commercial catalyst was higher than those of the present catalysts, the selectivity for 4-t-butylethylbenzene (4-t-BEB) was low. The optimum feed ratio (ethylbenzene:t-butyl alcohol) was 2:1 and the feed rate was 1.65 h−1 for high ethylbenzene conversion and 4-t-BEB selectivity. Time-on-stream studies showed slow catalyst deactivation. Highly crystalline ZSM-5 zeolites are therefore better than a commercial zeolite for para-selective alkylation of alkyl aromatics. They do not require much post-modification for high para selectivity. A fluoride medium is therefore better than an alkaline medium for obtaining highly crystalline para-selective ZSM-5 zeolites.

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Effect of Ni Doping on the Catalytic Properties of Nanostructured Peony-Like CeO2 XIAN Cun-Ni, WANG Shao-Fei, SUN Chun-Wen, LI Hong, CHEN Xiao-Hui, CHEN Li-Quan 2013, 34 (2):  305-312.  DOI: 10.1016/S1872-2067(11)60466-X Abstract ( 2341 )   [Full Text(HTML)] () PDF (852KB) ( 942 )   Nanostructured ceria materials have attracted wide attention as catalysts, and the doping of these materials with rare earth elements to modify their catalytic activity has been comprehensively investigated. A novel type of Ni-doped hierarchical nanostructured peony-like ceria (PCO) has been prepared and its catalytic activity is investigated and compared with that of Ni-loaded samples. The prepared Ni-doped ceria have nanoscale grain sizes and open mesopores. This unique morphology endows it with superior catalytic activity for the oxidation of CO and the partial oxidation of methane. It is found that extra oxygen vacancies are generated in the ceria, and the reducibility of the ceria is highly enhanced after Ni-doping. The catalytic activity for CO oxidation is improved after Ni-doping, compared with that of pure ceria and Ni-loaded ceria. In the reaction for the partial oxidation of methane, the 3.8 atm% Ni-loaded PCO sample realizes a higher CH4 conversion than the Ni-doped ceria. However, it is found that the onset temperature for CH4 conversion decreases from 400 °C for the pure PCO and 3.8 atm% Ni-loaded PCO sample, to 340 °C for the 5.7 atm% Ni-doped PCO sample.

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Relationship between the structure and activity of ruthenium cata-lysts in the catalytic ozonation of dimethyl phthalate WANG Jian-Bing, WANG Can, YANG Chun-Li, WANG Guo-Qing, ZHU Wan-Peng 2013, 34 (2):  313-321.  DOI: 10.1016/S1872-2067(11)60479-8 Abstract ( 934 )   [Full Text(HTML)] () PDF (981KB) ( 889 )   Ruthenium catalysts on various activated carbon (AC) supports were prepared using conventional calcination and microwave irradiation. Their activity in the catalytic ozonation of dimethyl phthalate was studied. The relationship between the structure and activity was investigated. All the supports and catalysts increased total organic carbon removal. The activity order was Ru/coal-AC > nutshell-AC > Ru/nutshell-AC > Ru/coconut-AC ≈ coal-AC > coconut-AC. The supported Ru particles diffused into the macropores, which increased mass transfer resistance in catalytic ozonation and decreased the probability that the reactants can contact the active phase on the interior surface. This was one reason why the activity of nutshell-AC and Ru/nutshell-AC was lower than that of Ru/coal-AC. A difference in Ru dispersion on the surface of the catalyst also caused the activity difference. The active phase on the surface of nutshell-AC can be changed by microwave irradiation, which caused Ru/nutshell-AC to even be less active than the corresponding support. As compared to the use of conventional calcination, the use of microwave irradiation enhanced the metal dispersion and catalytic activity of Ru/coal-AC.

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Low Temperature CO Oxidation on Ni-Promoted CuO-CeO2 Catalysts CHEN Guo-Xing, LI Qiao-Ling, WEI Yu-Cai, FANG Wei-Ping, YANG Yi-Quan 2013, 34 (2):  322-329.  DOI: 10.1016/S1872-2067(11)60468-3 Abstract ( 2297 )   [Full Text(HTML)] () PDF (506KB) ( 1242 )   A series of Ce20Cu5NiyOx catalysts for CO oxidation at low temperature were prepared and characterized by N2 adsorption, X-ray diffraction, temperature-program reduction by H2, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Ce20Cu5Ni0.4Ox exhibited the highest catalytic activity. The addition of NiO increased the amount of copper ions doped into the CeO2 matrix and gave more oxygen vacancies in ceria by the formation of a Ni-O-Ce solid solution. XPS results showed that large quantities of Cu+, Ce3+, and lattice oxygen existed in the fresh Ce20Cu5Ni0.4Ox catalyst. Cu+ ions in the catalyst can easily migrate to the ceria lattice to form a Cu-O-Ce solid solution, which enhanced the release of the lattice oxygen of the oxides under a reducing atmosphere. The high catalytic activity of Ce20Cu5Ni0.4Ox is due to the promoter giving increased amounts of Cu+ in the catalyst and the formation of solid solutions of both Cu-O-Ce and Ni-O-Ce.

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Effects of composite oxide supports on catalytic performance of Ni-based catalysts for CO methanation ZHANG Han, DONG Yun-Yun, FANG Wei-Ping, LIAN Yi-Xin 2013, 34 (2):  330-335.  DOI: 10.1016/S1872-2067(11)60485-3 Abstract ( 2426 )   [Full Text(HTML)] () PDF (715KB) ( 1393 )   Metal-oxide-modified NiO/Al2O3 catalysts for methanation of CO were prepared using a modified grinding-mixing method and characterized using X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption isotherms, temperature-programmed reduction by H2, temperature-programmed desorption by H2, Raman spectroscopy, and X-ray photoelectron spectroscopy. The results show that the activity of an MgO-modified NiO/Al2O3 catalyst is better than those of NiO/ZrO2-Al2O3 and NiO/SiO2-Al2O3 in the reaction temperature range 300–700 °C. The incorporation of a metal oxide into NiO/Al2O3 was found to weaken Ni–Al interactions, leading to generation of large numbers of active Ni species, and this was confirmed to be responsible for the improvement in the performances of the catalysts in the methanation reaction.

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Gold supported on nitrogen-incorporated TS-1 for gas-phase epoxidation of propylene LIU Yi-Wu, ZHANG Xiao-Ming, SUO Ji-Shuan 2013, 34 (2):  336-340.  DOI: 10.1016/S1872-2067(11)60474-9 Abstract ( 2139 )   [Full Text(HTML)] () PDF (560KB) ( 759 )   Nitrogen-incorporated titanium silicalite-1 (NTS-1) was used to prepare a supported gold catalyst for direct gas-phase epoxidation of propylene using H2 and O2. The NTS-1 was synthesized by direct calcination of the TS-1 powder in a flow of NH3 at high temperature. Gold catalyst supported on NTS-1 was synthesized by the deposition-precipitation method. The samples were characterized by X-ray diffraction, N2 adsorption-desorption, diffuse reflectance ultraviolet-visible spectroscopy, inductively coupled plasma optical emission spectrometry, elemental analysis, X-ray photoelectron spectroscopy, and transmission electron microscopy. The results indicated that nitrogen was incorporated into the TS-1 framework, and that the NTS-1 preserved the multidimensional fatigue inventory (MFI) structure well. It was found that NH3-treatment resulted in decreased acidity of the TS-1 zeolite support and improved both the Au capture efficiency and dispersion, which remarkably improved the catalytic performance. The enhanced activity was ascribed to the decrease in acidic surface sites and the ligand effect of the terminal NH2 groups on the support surface.

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Cu-doped mesoporous VOx-TiO2 in catalytic hydroxylation of benzene to phenol XU Dan, JIA Li-Hua, GUO Xiang-Feng 2013, 34 (2):  341-350.  DOI: 10.1016/S1872-2067(11)60487-7 Abstract ( 2068 )   [Full Text(HTML)] () PDF (854KB) ( 855 )   Liquid phase hydroxylation of benzene to phenol with hydrogen peroxide over VOx-TiO2 catalyst samples with Cu as a second metal was investigated. A series of Cu/VOx-TiO2 (vanadium loading was 4.3%) catalysts were prepared within the range of Cu loading (0.29%–2.5%) and calcined at the temperatures of 350–650 °C. The catalyst samples were characterized by N2 adsorption-desorption, scanning electron microscopy, H2 temperature-programmed reduction, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. After the addition of Cu, the Cu/VOx-TiO2 catalyst had more ordered mesoporous structure as compared with the VOx-TiO2 catalyst, and the vanadium was monodispersed on the TiO2 support. The presence of Cu2+ ions on the catalyst surface was shown by XPS measurements. These Cu2+ ions probably contributed to the dispersion of vanadium on the surface of the TiO2 support, and the more facile reduction of VOx. The Cu2+ ions also strengthened the thermostability of the Cu/VOx-TiO2 catalyst. The effects of some other variables (Cu loading, catalyst amount, and reaction temperature) on the catalytic performance were also investigated.

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Biotechnological production of 2,3-butanediol stereoisomers: synthetic mechanism and realized methods SHEN Meng-Qiu, JI Xiao-Jun, NIE Zhi-Kui, XIA Zhi-Fang, YANG Han, HUANG He 2013, 34 (2):  351-360.  DOI: 10.3724/SP.J.1088.2013.20737 Abstract ( 2030 )   [Full Text(HTML)] () PDF (470KB) ( 1398 )   2,3-Butanediol, an important fine chemical, has been widely used in many areas. Containing two chiral centers, the molecule of 2,3-butanediol contains three stereoisomers, namely (S,S)-, (R,R)-, and meso-2,3-butanediol, which are especially crucial in providing chiral groups for the synthesis of fine chemicals and high-value pharmaceuticals. In this review, the synthetic mechanisms of different 2,3-butanediol stereoisomers are firstly revisited. Some strategies for efficient and economical pure 2,3-butanediol stereoisomers production, including constructing whole cell biocatalysts and constructing metabolic pathways using the emerging synthetic biology methods, are summarized. It is also pointed out that the focus of future research should be placed on improving the biosynthetic capability of different stereo- isomers using the synthetic biology methods, and establishing efficient downstream separation methods for economical 2,3-butanediol stereoisomers recovering process.

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Effect of Alkali Earth Metals on Performance of Zirconium-Based Perovskite Composite Oxides Supported Ruthenium for Ammonia Synthesis WANG Zi-Qing, MA Yun-Cui, LIN Jian-Xin, WANG Rong, WEI Ke-Mei 2013, 34 (2):  361-366.  DOI: 10.3724/SP.J.1088.2012.20744 Abstract ( 2171 )   [Full Text(HTML)] () PDF (383KB) ( 906 )   Zirconium-based perovskite materials with different alkaline earth metals were synthesized by the citric acid method and used as supports for ruthenium catalysts to catalytic ammonia synthesis reaction. The effects of alkaline earth metals on the texture properties, basicity, and catalytic activity were discussed. Additionally, the desorption properties of H2 on the surface of various catalysts were characterized by temperature-programmed desorption. The results showed that there were lots of strong basic sites appeared on the Ca, Sr, and Ba perovskite-style supports, and the order of activity was Ba > Sr > Ca. The addition of different alkaline earth metals not only affected the electron donating ability but also influenced the metal-support interaction as well as the adsorption-desorption properties of these catalysts. The adsorption of H2 was inhibited significantly by the presence of BaZrO3 and increased the number of active sites for dissociatively adsorbed N2 which may be the major reason why the Ru/BaZrO3 catalyst exhibited so high activity for ammonia synthesis.

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Photocatalytic Properties of Magnetically Separable Composite Photocatalyst Nanosphere Prepared by Liquid-Phase Deposition XU Shi-Hong, TAN Dong-Dong, LU Wei, SHI Peng-Hui, BI De-Fu, MA Chun-Yan, SHANGGUAN Wen-Feng 2013, 34 (2):  367-372.  DOI: 10.3724/SP.J.1088.2013.20766 Abstract ( 2040 )   [Full Text(HTML)] () PDF (831KB) ( 795 )   A novel magnetically separable composite photocatalyst nanosphere TiO2@SiO2@NiFe2O4 was prepared by a reverse micelle method and liquid phase deposition technique and characterized by X-ray diffraction and transmission electron microscopy. The results indicated that the nickel ferrite core nanoparticles are completely encapsulated into silica nanospheres as a support (SiO2@NiFe2O4), and titania nanoparticles are deposited onto the surface of SiO2@NiFe2O4 nanospheres, forming a TiO2 shell for photocatalysis. The degradation experiments of methyl orange indicated that when the molar ratio of H3BO3 to [TiF6]2- is set at 4, the as-prepared photocatalyst calcined at 300 °C presents the highest photocatalytic activity.

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Effect of Cr-Doping on the Acidity and Pore Structure of Mesoporous Magnesium Fluoride NIU Huai-Cheng, LI Li-Chun, LI Ying, GUO Li, TANG Hao-Dong, HAN Wen-Feng, LIU Hua-Zhang 2013, 34 (2):  373-378.  DOI: 10.3724/SP.J.1088.2012.20854 Abstract ( 1766 )   [Full Text(HTML)] () PDF (791KB) ( 894 )   The effect of Cr-doping on the acidity and pore structure of mesoporous magnesium fluoride prepared by co-precipitation was investigated. The prepared MgF2, CrF3, and Cr(x)-MgF2 with different Cr loadings were characterized by N2 adsorption-desorption, X-ray powder diffraction, transmission electron microscopy, pyridine adsorption Fourier transform infrared spectroscopy, and NH3 temperature-programmed desorption. The catalytic activity of MgF2 and Cr(x)-MgF2 was tested in the disproportionation of CHClF2. The doped Cr in the MgF2 results in the improvements of the specific surface area and surface Lewis acidity. Meanwhile, the MgF2 catalyst samples doped with Cr show excellent catalytic performance in CHClF2 disproportionation.

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Catalytic performance of mesoporous material supported bimetallic carbide Ni-b-Mo2C/SBA-16 catalyst for CH4/CO2 reforming to syngas NAO Mo-Han, FU Xiao-Juan, LEI Yan-Qiu, SU Hai-Quan 2013, 34 (2):  379-384.  DOI: 10.3724/SP.J.1088.2013.20857 Abstract ( 2072 )   [Full Text(HTML)] () PDF (728KB) ( 838 )   Mesoporous molecular sieve SBA-16 supported bimetallic carbide catalyst Ni-b-Mo2C/SBA-16 was prepared using the impregnation and thermal decomposition method. N2 adsorption-desorption isotherms, powder X-ray diffraction, and transmission electron microscopy measurements show that the active components were uniformly dispersed on the support, and the catalyst still remained ordered mesoporous structure of SBA-16. Catalytic performance measurements show that the catalyst exhibited higher conversion rate of CH4, CO2, and selectivity of CO, H2, and remarkable anti-coke effect.

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Preparation, Characterization, and Photocatalytic Properties of Pt/BiOCl Nanoplates YU Chang-Lin, CHEN Jian-Chai, CAO Fang-Fang, LI Xin, FAN Qi-Zhe, YU Jimmy C, WEI Long-Fu 2013, 34 (2):  385-390.  DOI: 10.3724/SP.J.1088.2012.20904 Abstract ( 2453 )   [Full Text(HTML)] () PDF (540KB) ( 1945 )   A series of novel Pt/BiOCl nanoplate photocatalysts were synthesized by a photodeposition method. The as-synthesized products were characterized by N2 physical adsorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, photoluminescence (PL) emission spectroscopy, and UV-Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity of the samples was evaluated by photocatalytic degradation of acid orange II under both UV light (λ = 254 nm) and visible light irradiation. The N2 physical adsorption test showed that the deposition of Pt nanoparticles could not produce obvious change in the specific surface area of the catalyst. The UV-Vis DRS results indicated that the presence of Pt nanoparticles could effectively increase the visible light absorption ability of Pt/BiOCl. The PL spectra indicated that Pt could effectively suppress the recombination of photogenerated hole-electron pairs of Pt/BiOCl. Activity tests showed that the deposition of Pt (1%–2%, mass fraction) greatly promotes the UV right photocatalytic activity. Pt also brought about an obvious visible light activity, which could be attributed to the visible light absorption and plasmon photocatalysis role of deposited Pt nanoparticles.

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Catalytic stability of othro-chloronitrobenzene hydrogenation on Ru-Fe/C catalyst XU Xiang-Sheng, CHEN Ao-Ang, ZHOU Li, LI Xiao-Qing, GU Hui-Zi, YAN Xin-Huan 2013, 34 (2):  391-396.  DOI: 10.3724/SP.J.1088.2013.20959 Abstract ( 1770 )   [Full Text(HTML)] () PDF (466KB) ( 833 )   Ru-based crystalline catalysts were prepared by the impregnation method using different supports and promoters and were applied in the in-situ liquid phase catalytic hydrogenation of ortho-chloronitrobenzene (o-CNB) to ortho-chloroaniline (o-CAN). The effects of different preparation factors (including impregnation sequence, promoters, reduction temperature, supporters and promoter content) on the catalyst stability were investigated. The Ru-Fe/C catalyst was systematically characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and N2 adsorption-desorption with regard to physical-chemical properties such as particle size and distribution, electronic state, adsorption species, and surface parameters. The results indicated that the 0.5%Ru-15%Fe/C catalyst has higher hydrogenation activity with 99.7% o-CNB conversion and 98.7% o-CAN selectivity. The catalyst can be run for 140 h without obvious deactivation. Based on the results of characterization, the poisonous CO adsorption on catalyst surface was the main reason for deactivation, and the catalyst regeneration was studied.