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Chinese Journal of Catalysis
2012, Vol. 33, No. 9
Online: 11 September 2012


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Shi and coworkers studied the interactions of CuO active components with γ-Al₂O₃, CeO₂, and CeO₂/γ-Al₂O₃ supports. They found that CuO clusters could be stabilized based on the strong Cu–Ce interaction. The stabilized CuO clusters play a key role in NO, CO, and C₃H₆ abatement. See the article on pages 1455–1462.

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Table of Contents for Vol. 33 No. 9 2012, 33 (9):  0-0.  Abstract ( 999 )   PDF (1494KB) ( 780 )

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Recent Progress in Carbonylation of Epoxides FAN Qi-Jia, LIU Jian-Hua, CHEN Jing, XIA Chun-Gu 2012, 33 (9):  1435-1447.  DOI: 10.3724/SP.J.1088.2012.20515 Abstract ( 2842 )   [Full Text(HTML)] () PDF (777KB) ( 1207 )   Carbonylation reactions that introduce carbonyl moiety into organic and inorganic substrates have the advantages of atom economical selectivity and environmental benignancy. Recently, it has been one of the challenging and attractive subjects in the field of value-added utilization of C1 resources and a bridge between petrochemical industry and C1 chemistry. The important transformation has drawn considerable attention from both academia and industry. We aim to present recent progress in cobalt carbonyl complexes catalyzed carbonylation of epoxides, including ring-expansion carbonylation, ring-opening carbonylative copolymerization, and ring-opening carbonylation. The development prospects are also discussed.

Research Briefing

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BiMnO3 Perovskite Catalyst for Selective Catalytic Reduction of NO with NH3 at Low Temperature ZHANG Yi-Bo, WANG De-Qiang, WANG Jing, CHEN Qu-Fei, ZHANG Zhen-Dong, PAN Xi-Qiang, MIAO Zhen-Zhen, ZHANG Bin, WU Zhi-Jian, YANG Xiang-Guang 2012, 33 (9):  1448-1454.  DOI: 10.1016/S1872-2067(11)60439-7 Abstract ( 2522 )   [Full Text(HTML)] () PDF (516KB) ( 1176 )   A perovskite was used for selective catalytic reduction of NO with NH3 (NH3-SCR) at low temperature in the presence of excess oxygen. The BiMnO3 perovskite catalyst showed high activity in NH3-SCR at 100–240 oC. Experiment and DFT calculation showed that more Lewis acid sites and a high concentration of surface oxygen on BiMnO3 as compared with LaMnO3 were responsible for its better performance. In addition, BiMnO3 was also resistant to water vapor and a mixture of H2O and SO2.

Research papers

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Copper Oxide Clusters Stabilized by Ceria for CO, C3H6, and NO Abatement SHI Chuan, XU Li, ZHU Ai-Min, ZHANG Yu-Zhuo, QU Ze-Tang 2012, 33 (9):  1455-1462.  DOI: 10.1016/S1872-2067(11)60417-8 Abstract ( 2705 )   [Full Text(HTML)] () PDF (590KB) ( 895 )   A strong interaction between a metal oxide and support has long been indicative of its promotion of catalytic activities. In connection with this, we investigated the interaction of CuO with γ-Al2O3 and CeO2 for producing highly efficient catalysts for CO, C3H6, and NO abatement. In particular, the dispersion and thermal aging resistance of CuO clusters on different supports were studied. CuO clusters can be stabilized by interaction with CeO2, while on γ-Al2O3 they aggregated into larger particles at high CuO loadings. On the other hand, due to the poor thermal stability of CeO2, CuO clusters dispersed on it were sintered during an aging treatment at 950 oC. Accordingly, by pre-dispersing CeO2 on γ-Al2O3 followed by CuO dispersion, stabilized CuO clusters were obtained that were based on the superior aging resistance of the γ-Al2O3 support. Therefore, better catalytic performance and thermal aging properties were obtained with a CuO/CeO2/γ-Al2O3 catalyst as compared with CuO/γ-Al2O3 and CuO/CeO2 samples.

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Reduction of Nitrobenzene with Hydrazine Hydrate Catalyzed by Acid-Treated Activated Carbon ZHOU Hong-Yue, SHI Lei, SUN Qi 2012, 33 (9):  1463-1469.  DOI: 10.1016/S1872-2067(11)60426-9 Abstract ( 3327 )   [Full Text(HTML)] () PDF (486KB) ( 864 )   Activated carbons, which were modified by chemical treatment in aqueous solutions of HNO3, HCl, and H2SO4 or in gaseous N2 and H2, have been tested as catalysts in the reduction of nitrobenzene using hydrazine hydrate as hydrogen donor. Fourier transform infrared spectroscopy analysis and Boehm titration reveal that the chemical treatment leads to the formation of various oxygen functional groups on the surface of the activated carbon. These oxygen functional groups can induce the decomposition of hydrazine hydrate and influence the adsorption of nitrobenzene on the surface of the activated carbon. The catalytic activity is correlated to that of the oxygen functional groups, which suggests that an abundance of surface oxygen functional groups is favourable for this reaction. The activated carbon treated by hydrochloric acid had the largest amount of oxygen functional groups and exhibited the highest activity for nitrobenzene reduction to aniline.

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Polyvinylpolypyrrolidoniume Tribromide as an Efficient Catalyst for the Acetylation of Alcohols and Phenols Arash GHORBANI-CHOGHAMARANI, Nasrin POURBAHAR 2012, 33 (9):  1470-1473.  DOI: 10.1016/S1872-2067(11)60428-2 Abstract ( 2065 )   [Full Text(HTML)] () PDF (291KB) ( 909 )   An efficient and versatile procedure for the acetylation of alcohols and phenols using acetic anhydride in the presence of a catalytic amount of polyvinylpolypyrrolidoniume tribromide has been successfully developed. Primary, secondary, and tertiary alcohols, as well as a selection of the phenolic compounds, have been successfully acetylated according to this procedure, with good to high yields being achieved over short reaction times.

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Conversion of Isobutane in Presence of Carbon Dioxide over Molybdenum Oxide Catalysts Obtained from Heteropolymolybdate Precursors Ahmed AOUISSI, Daif ALDHAYAN, Saad ALKAHTANI 2012, 33 (9):  1474-1479.  DOI: 10.1016/S1872-2067(11)60412-9 Abstract ( 1827 )   [Full Text(HTML)] () PDF (333KB) ( 997 )   Molybdenum based oxide catalysts Mo-H, Mo-Fe, Mo-Ce, and Mo-Sn were prepared by calcining H3PMo12O40, Fe1.5PMo12O40, Ce1.5PMo12O40, and Sn1.5PMo12O40 heteropolyanion precursors at 700 °C, respectively. The prepared oxides have been characterized and tested for the dehydrogenation of isobutane (IB) to isobutene in the presence of CO2. The effects of temperature, time on stream, and CO2/IB ratio were investigated. It was found that α- and b-MoO3 phases were present in all catalysts. Catalytic tests showed that increasing the reaction temperature increased both the conversion and isobutene selectivity, whereas increasing the CO2/IB molar ratio increased the conversion but decreased the selectivity for isobutene. Iron was found to be an effective additive element for the enhancement of catalytic activity compared with Ce and Sn.

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Thermal Stability of Gold Catalyst Supported on Mesoporous Titania Nanofibers MA Xuan-Xuan, ZHU Yin-Hua, LI Li-Cheng, WANG Chang-Song, LU Xiao-Hua, YANG Zhu-Hong 2012, 33 (9):  1480-1485.  DOI: 10.1016/S1872-2067(11)60415-4 Abstract ( 2958 )   [Full Text(HTML)] () PDF (548KB) ( 894 )   By deposition-precipitation with urea method, gold was loaded on mesoporous TiO2 whisker, which was prepared from a potassium titanate whisker precursor through solid phase sintering process. The morphology and structure of these as-prepared catalysts were characterized by N2 adsorption-desorption, X-ray diffraction, and transmission electron microscopy. The reduction of 4-nitrophenol to 4-aminophenol by NaBH4 was evaluated as a probe reaction. After calcination at high temperature, the activity of the catalysts supported on mesoporous TiO2 nanofiber was well maintained, and the particle size of gold nanoparticles was hardly changed. This might be attributed to the peculiar crystallographic structure and mesoporous nanoarchitecture of the mesoporous TiO2 whisker.

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Well-Ordered Mesoporous Silica Nanoparticles as a Recoverable Catalyst for One-Pot Multicomponent Synthesis of 4H-Chromene Derivatives Yaghoub SARRAFI, Ebrahim MEHRASBI, Amir VAHID, Mahmood TAJBAKHSH 2012, 33 (9):  1486-1494.  DOI: 10.1016/S1872-2067(11)60423-3 Abstract ( 2376 )   [Full Text(HTML)] () PDF (568KB) ( 1284 )   A simple, efficient and environmentally benign protocol for the synthesis of 4H-chromene derivatives was developed using bio-compatible, neutral, and recoverable mesoporous silica nanoparticles as a catalyst. The 4H-chromene derivatives were obtained in excellent yields by three component reaction of an aldehyde or isatin, malononitrile, and cyclic 1,3-diketones in ethanol at 60 °C.

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Photodegradation of Organic Dye by CoS2 and Carbon(C60, Graphene, CNT)/TiO2 Composite Sensitizer MENG Zeda, OH Wonchun 2012, 33 (9):  1495-1501.  DOI: 10.1016/S1872-2067(11)60429-4 Abstract ( 2172 )   [Full Text(HTML)] () PDF (924KB) ( 1145 )   CoS2, CoS2-C60/TiO2, CoS2-CNT/TiO2, and CoS2-Graphene/TiO2 were prepared. The TiO2 products had the anatase phase structure and interesting surface compositions. X-ray diffraction patterns of the CoS2-carbon/TiO2 composites showed a single and clear anatase phase and the CoS2 structure. Scanning electron microscopy characterization of the texture on the CoS2-carbon/TiO2 composites showed a homogenous composition. Energy-dispersive X-ray spectra for elemental identification showed the presence of C and Ti with strong Co and S peaks from the CoS2-carbon/TiO2 composites. The composites obtained were also characterized by transmission electron microscopy and UV-Vis spectroscopy. CoS2-carbon/TiO2 composites showed excellent photocatalytic activity for the degradation of methylene blue under visible light irradiation. This was attributed to both photocatalysis on the TiO2 support and charge transfer by the carbon nanomaterial, and the introduction of CoS2 to enhance transfer of photogenerated electrons.

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Microwave Assisted Sol-Gel Synthesis of MgO Nanoparticles and Their Catalytic Activity in the Synthesis of Hantzsch 1,4-Dihydropyridines Hakimeh MIRZAEI, Abolghasem DAVOODNIA 2012, 33 (9):  1502-1507.  DOI: 10.1016/S1872-2067(11)60431-2 Abstract ( 2691 )   [Full Text(HTML)] () PDF (229KB) ( 2874 )   A microwave-assisted sol-gel method was employed for the preparetion of nano-sized MgO particles using Mg(NO3)2·6H2O as precursor and deionized water as solvent. The sample calcined at 500 °C had a high specific surface area of 243.2 m2/g and particles sizes from 9.5 to 10.5 nm. For comparison, MgO nanoparticles were also synthesized without microwave irradiation. X-ray diffraction (XRD) characterization showed the formation of smaller particles after microwave irradiation. The structure and morphology of the MgO particles were analyzed by N2 adsorption-desorption, XRD, scanning electron microscopy, and transmission electron microscopy. Their catalytic behavior was studied with the one-pot synthesis of Hantzsch 1,4-dihydropyridines from the reaction of aromatic aldehydes, ethyl acetoacetate, and ammonium acetate. The MgO nanoparticles have high catalytic activity and gave the desired products in good to high yields. The catalyst can be easily recovered by filtration and was used at least three times with only a slight reduction in its catalytic activity.

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Effect of Calcination Temperature on Characteristics and Performance of Ni/MgO Catalyst for CO2 Reforming of Toluene KONG Meng, YANG Qi, LU Wen, FAN Zhe-Yong, FEI Jin-Hua, ZHENG Xiao-Ming, Thomas D. WHEELOCK 2012, 33 (9):  1508-1516.  DOI: 10.1016/S1872-2067(11)60424-5 Abstract ( 2770 )   [Full Text(HTML)] () PDF (656KB) ( 919 )   A Ni/MgO catalyst for CO2 reforming of toluene was prepared by impregnating MgO with Ni(NO3)2. During calcination, some of the NiO diffused into the MgO and formed a solid solution structure of NiO-MgO, which was analyzed by Raman spectroscopy. In the temperature-programmed reduction with hydrogen analysis, only a small part of the Ni species in the outermost layer was reduced to metallic Ni at 700 oC. The calcination temperature played a key role in determining the subsequent catalytic activity of Ni/MgO, consequently the catalyst calcined at 600 oC had the highest activity. This catalyst also had the highest surface concentration of reduced Ni, which probably accounted for its high activity. During the reforming tests, a small amount of coke was deposited on Ni/MgO catalyst. Polyaromatic compounds were observed by Raman spectroscopy. The coke was probably responsible for the activity loss of Ni/MgO.

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Titanium Dioxide Nanoparticles Catalyzed Synthesis of Hantzsch Esters and Polyhydroquinoline Derivatives Mahmood TAJBAKHSH, Ehsan ALAEE, Heshmatollah ALINEZHAD, Mohammad KHANIAN, Fatemeh JAHANI, Samad KHAKSAR, Parizad REZAEE, Mahgol TAJBAKHSH 2012, 33 (9):  1517-1522.  DOI: 10.1016/S1872-2067(11)60435-X Abstract ( 2555 )   [Full Text(HTML)] () PDF (361KB) ( 1278 )   1,4-Dihydropyridine and polyhydroquinoline derivatives have been prepared efficiently in a one-pot synthesis via Hantzsch condensation using nanosized titanium dioxide as a heterogeneous catalyst. The present methodology offers several advantages such as excellent yields, short reaction times (30–120 min), environmentally benign, and mild reaction conditions. The catalyst can be readily separated from the reaction products and recovered in excellent purity for direct reuse.

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WO3 Modification of MnOx/TiO2 Catalysts for Low Temperature Selective Catalytic Reduction of NO with Ammonia ZHANG Ya-Ping, WANG Xiao-Lei, SHEN Kai, XU Hai-Tao, SUN Ke-Qin, ZHOU Chang-Cheng 2012, 33 (9):  1523-1531.  DOI: 10.1016/S1872-2067(11)60427-0 Abstract ( 2645 )   [Full Text(HTML)] () PDF (666KB) ( 1047 )   A series of WO3-modified MnOx/TiO2 catalysts were prepared by three different impregnation methods and were investigated by specific surface area measurement, X-ray diffraction, laser Raman spectroscopy, H2 temperature-programmed reduction, high-resolution transmission electron microscopy, and in situ Fourier transform infrared spectroscopy. The three-component catalysts obtained with the one-step impregnation exhibited the best catalytic activity. The characterization data revealed that a synergism between tungsten and manganese oxide existed in the catalysts when tungsten was loaded either prior to or simultaneously with manganese, which made the active components better dispersed and blocked the transformation of TiO2 from the anatase to rutile structure. The manganese oxide existed in the form of Mn2O3 on all the samples but was accompanied by a small amount of MnO2 for 15%MnOx-5%WO3/TiO2. WO3 improved the reducibility and enhanced the amount and strength of the surface acid sites, especially the Brönsted acid sites and promoted the formation of the active intermediate (-NH2). Lewis acid sites had the major role in the low temperature selective catalytic reduction reaction while surface -NH2 was an important intermediate species.

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Synthesis of Colloidal CuO/γ-Al2O3 by Microemulsion and Its Catalytic Reduction of Aromatic Nitro Compounds Sachin U. NANDANWAR, Mousumi CHAKRABORTY 2012, 33 (9):  1532-1541.  DOI: 10.1016/S1872-2067(11)60433-6 Abstract ( 2306 )   [Full Text(HTML)] () PDF (689KB) ( 1413 )   Monodispersed colloidal copper oxide nanoparticles were synthesized by water-in-oil microemulsion using CuCl2·H2O and NaOH. The effect on CuO particle size was studied by varying the water-to-surfactant molar ratio, precursor concentration and molar ratio of NaOH to CuCl2. The morphology, size and size distribution of the particles were studied by transmission electron microscopy and dynamic light scattering. Dispersion destabilization of the colloidal copper oxide nanoparticles was detected by a Turbiscan apparatus. CuO/γ-Al2O3 catalysts were prepared by dispersing highly stable CuO nanoparticles on γ-alumina by mechanical stirring. The catalysts were analyzed by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron, and X-ray diffraction, which confirmed the uniform dispersion of CuO on the support. The reduction of the nitro aromatic compounds, 4-nitrophenol, 3-nitrophenol, and 2-nitrophenol, were studied. The CuO/γ-Al2O3 catalysts were active for the reduction of these nitro aromatic compounds.

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A Simple and Environmentally Benign Protocol for Biginelli Reactions Catalyzed by Silica-Bonded S-Sulfonic Acid Mahmood TAJBAKHSH, Yousef RANJBAR, Abdolhosein MASUODI, Samad KHAKSAR 2012, 33 (9):  1542-1545.  DOI: 10.1016/S1872-2067(11)60432-4 Abstract ( 2307 )   [Full Text(HTML)] () PDF (312KB) ( 1096 )   A protocol for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and -thiones was developed by means of a three-component condensation of an aldehyde, a β-dicarbonyl compound, and urea or thiourea in acetic acid catalyzed by silica-bonded S-sulfonic acid. Compared to the classical Biginelli reaction conditions, this new protocol has the advantages of consistently excellent yields and short reaction times. After the reaction, the catalyst could be recovered easily and reused with little change in its activity.

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Catalytic Performance and Synergetic Effect of Mo-V/Al2O3 in Residue Hydrotreatment JIA Yan-Zi, YANG Qing-He, SUN Shu-Ling, NIE Hong, LI Da-Dong 2012, 33 (9):  1546-1551.  DOI: 10.3724/SP.J.1088.2012.20231 Abstract ( 2525 )   [Full Text(HTML)] () PDF (627KB) ( 737 )   Mo-V/Al2O3 catalyst samples with different atom ratios of Mo/(Mo+V) were prepared by pore volume impregnation. The catalyst samples were characterized by Raman spectroscopy, H2 temperature-programmed reduction, and high resolution transmission electron microscopy. The catalytic performance of Mo-V/Al2O3 samples for model molecules (naphthalene) and for real feedstock (Kuwait atmosphere residue) was measured after sulfidation. Hydrogenation (HYD), hydrodemetallization (HDM), and hydrodesulfurization (HDS) were assessed. It can be concluded that Mo and V exhibited a synergetic effect in model molecules HYD and residue HDM reactions. Because the metals and sulfurs exist in different forms in residue and the V–S and V–Mo–S phases are more active for HDM than HDS, it is observed that the Mo-V/Al2O3 catalyst exhibited higher HDM activity and lower HDS activity compared with the Ni-Mo/Al2O3 catalyst.

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In-Situ FT-IR Study on Methane Combustion over Pd/NiAl2O4 Catalyst LIU Ying, WANG Sheng, GAO Dian-Nan, PAN Qiu-Shi, WANG Shu-Dong 2012, 33 (9):  1552-1557.  DOI: 10.3724/SP.J.1088.2012.20535 Abstract ( 2397 )   [Full Text(HTML)] () PDF (577KB) ( 820 )   The mechanism of methane combustion on Pd/NiAl2O4 catalyst was studied by in-situ FT-IR spectroscopy. The results showed that the transformation from formate to carbonate was the rate-determining step for the reaction. After reaction under lean fuel condition, the active site of pre-reduced catalyst was still Pd-PdO mixed phase. The existence of metal Pd would convert O2 to O2– species, which would facilitate the transformation from formate to carbonate.

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Preparation and Performance of Mordenite Zeolite Membrane Using Fluoride Route REN Xiu-Xiu, YANG Jian-Hua, CHEN Zan, YANG Xing-Bao, LU Jin-Ming, ZHANG Yan, WANG Jin-Qu 2012, 33 (9):  1558-1564.  DOI: 10.3724/SP.J.1088.2012.20436 Abstract ( 2132 )   [Full Text(HTML)] () PDF (1591KB) ( 813 )   High performance mordenite zeolite membranes in fluoride media with organic-free template were prepared on macroporous α-Al2O3 tubes by secondary growth. The seeding method was used hot dip-coating and could form a thin and compact layer. The effects of NaF content and Si/Al ratio on the morphology and pervaporation properties of the as-synthesized membranes were studied. The prepared membranes with a molar composition 6Na2O:1.2Al2O3:30SiO2:780H2O:1.5NaF for pervaporation experiments were carried out at 70 °C and vacuum pressure 400 Pa in a 91.5% EtOH/H2O system. The results indicated that the separation factor reached 6872 with flux 0.51 kg/(m2·h). The H2O concentration of permeation side for pervaporation of IPA/H2O, acetic acid/H2O systems can reach 100% (limit in GC detection). The membranes almost keep high selectivity as before after acid test with 1 mol/L acetic acid in the H2O/EtOH system. The membranes may have potential applications as membrane reactors in acetic ether production with a higher transformation ratio.

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Immobilization of Burkholderia Cepacia Lipase on Functionalized Ionic Liquids Modified Mesoporous Silica SBA-15 TANG Su-Su, HU Yi, YU Ding-Hua, ZOU Bin, JIANG Ling 2012, 33 (9):  1565-1571.  DOI: 10.3724/SP.J.1088.2012.20457 Abstract ( 2327 )   [Full Text(HTML)] () PDF (602KB) ( 1061 )   Mesoporous silica SBA-15 was modified by imidazole-based ionic liquids with alkyl group. The modified support samples were characterized by nitrogen adsorption-desorption, small-angle X-ray diffraction, Fourier transform infrared spectroscopy, elemental analysis, and scanning electron microscopy. The samples were used to immobilize Burkholderia cepacia lipase (BCL) and the influence of alkyl chain length of ionic liquid on enzymatic properties was investigated by the hydrolysis reaction of triacetin. The results revealed that functionalized ionic liquid modification did not destroy the structure of SBA-15. Compared with the immobilized lipase on parent SBA-15, the immobilized lipases on modified support samples were less sensitive to temperature and low pH and showed higher specific activity and stability. Thereinto, BCL immobilized on methyl-functionalized ionic liquid modified SBA-15 had the highest specific activity, which improved 2.4 folds compared with BCL immobilized on SBA-15. BCL immobilized on octyl-functionalized ionic liquid modified SBA-15 had the best thermal stability, reusability, storage stability, and stability in organic solvent.

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Li2ZrO3 Nanoparticles as Absorbent for in-Situ Removal of CO2 in Water-Gas Shift Reaction to Enhance H2 Production ZHANG Yuan-Zhuo, YU Zi-Ying, ZHANG Fu-Min, XIAO Qiang, ZHONG Yi-Jun, ZHU Wei-Dong 2012, 33 (9):  1572-1577.  DOI: 10.3724/SP.J.1088.2012.20352 Abstract ( 2865 )   [Full Text(HTML)] () PDF (631KB) ( 799 )   Ni/γ-Al2O3 catalyst with high activity in water-gas shift (WGS) reaction was prepared by an impregnation method, and nano-sized Li2ZrO3 absorbent with excellent CO2 capture properties was synthesized by a citrate sol-gel method. Two processes, WGS over 20% Ni/γ-Al2O3 catalyst alone and sorption-enhanced WGS (SE-WGS) over 20% Ni/γ-Al2O3 catalyst admixing with nano-sized Li2ZrO3 absorbent in a fixed-bed microreactor, towards the production of H2 were compared. The nano-sized Li2ZrO3 absorbent shows better CO2 capture properties than other CO2 absorbents reported so far in terms of uptake rate and reusability. Based on these excellent properties, the application of the developed Li2ZrO3 absorbent in sorption-enhanced reaction process (SERP) for the in-situ removal of CO2 produced from WGS leads to the equilibrium shift of the reaction to the production of H2 with high purity. The H2 purity higher than 98% can be achieved by SE-WGS at 823 K, a total pressure of 0.1 MPa, and a H2O/CO molar ratio of 4, demonstrating the concept of SERP for H2 production.

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Density Functional Theory Study of IB Metals Binding to Perfect and N-Doped Graphene YIN Wei, LIN Hua-Xiang, ZHANG Yong-Fan, HUANG Xin, CHEN Wen-Kai 2012, 33 (9):  1578-1585.  DOI: 10.3724/SP.J.1088.2012.20416 Abstract ( 3003 )   [Full Text(HTML)] () PDF (781KB) ( 1129 )   The binding strength of coinage metal (IB group) single and double atoms clusters on perfect or N-doped graphene has been studied with the periodic slab model using generalized gradient approximation (GGA). The calculated results indicated that N-doped graphene showed metallic electron properties rather than semimetallic ones of perfect graphene. Physical or weak chemical adsorption was got on perfect or graphite N-doped graphene with the binding energy around 0.5 eV. Chemical adsorption happened on pyridine N-doped graphene and pyrrole N-doped graphene with binding energy above 1 eV. Pyrrole N-doped graphene was less stable than graphite N-doped graphene or pyridine N-doped graphene. When adsorbates interacted with pyrrole N-doped graphene, it carried out the transition from pyrrole N-doped graphene to pyridine N-doped graphene, and the most stable adsorption structure based on pyridine N-doped graphene was obtained finally. The analysis of Mulliken population indicated that metal single atoms had positive charge while double atom clusters had negative charge after adsorbing on pyridine N-doped graphene. The density of states and orbital analysis demonstrated that Cu atom bonded with three atoms with dangling bonds while Au atom bonded with two of them in pyridine N-doped graphene.

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Hydrothermal Synthesis of TiO2-Al2O3 Composite Oxide and Catalytic Performance of Its Suppored NiMoP for Hydrodesulfurization of FCC Diesel HONG Wei, LIU Bai-Jun, WANG Hong-Bin, CHEN Yu 2012, 33 (9):  1586-1593.  DOI: 10.3724/SP.J.1088.2012.20330 Abstract ( 2339 )   [Full Text(HTML)] () PDF (614KB) ( 1091 )    The TiO2-Al2O3 composite oxide was synthesized by the hydrothermal method. The effects of hydrothermal temperature, reactant concentration, average molecular mass of polyethylene glycol, and polyethylene glycol concentration on the structural and textural properties of TiO2-Al2O3 composite oxide were studied. The composite oxide and NiMoP/TiO2-Al2O3 catalyst were characterized by powder X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy (SEM), thermogravimetric and differential thermal analysis (TG-DTA), NH3 temperature-programmed desorption (NH3-TPD), pyridine adsorption in situ infrared spectroscopy (Py-FTIR), and H2 temperature-programmed reduction (H2-TPR). The catalytic performance of the catalyst for hydrodesulfurization of fluid catalytic cracking (FCC) diesel was evaluated in a fixed-bed reactor with medium pressure. The results show that both specific surface area and pore volume of the TiO2-Al2O3 composite oxide increased with increasing hydrothermal temperature, reactant concentration, average molecular mass of polyethylene glycol, and polyethylene glycol concentration. Under the optimum conditions, the specific surface area and pore volume of the TiO2-Al2O3 composite oxide could reach up to 266 m2/g and 0.58 cm3/g, respectively. The specific surface area of NiMoP/TiO2-Al2O3 catalyst also reached as high as 175 m2/g. The results of NH3-TPD and Py-FTIR show that NiMoP/TiO2-Al2O3 catalyst has a weak acidity wherein Lewis acid is dominative. The NiMoP/TiO2-Al2O3 catalyst has higher desulfurization activity due to the existence of TiO2, which can decrease the strong interaction between the active phase and the support. Hydrodesulfurization activity for FCC diesel over NiMoP/TiO2-Al2O3 catalyst is thus 5.4% higher than that on the NiMoP/Al2O3 catalyst.

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Preparation and Characterization of Wool-Pd(0) Catalyst and Its Catalytic Performance for Oxidation of Alcohol in Water MA Heng-Chang, WANG Feng, CAO Wei, BAO Zhi-Kang, MA Yuan, YANG Zhi-Wang, LEI Zi-Qiang 2012, 33 (9):  1594-1600.  DOI: 10.3724/SP.J.1088.2012.20442 Abstract ( 2355 )   [Full Text(HTML)] () PDF (756KB) ( 831 )   Wool-Pd(0) catalyst was prepared successfully using nature biopolymer wool as stabilizer and supporter. The structure of the palladium catalyst was characterized by field emission scanning electron microscopy and X-ray photoelectron spectroscopy, and the results showed that Pd(0) particles are well dispersed on the surface of wool. Applying wool-Pd(0) catalyst in the oxidation of alcohol under optimized conditions, several parameters such as catalyst amount, base, reaction temperature, and reaction time were screened. It was found that 35 mg wool-Pd(0) catalyst is available for the oxidation of 0.2 mmol alcohol to corresponding aldehyde or ketone with higher conversion and selectivity in the presence of 0.2 mmol K2CO3 and using water as reaction medium. The heterogeneous catalyst is of good reusability in this reaction system.

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Synthesis, Purification, and Electrocatalytic Activity of Platinum Nanocatalyst with Globular Dendritic Structure SI Wei-Feng, LI Huan-Qiao, YIN Jie, LI Shu-Shuang, XIE Yan, LI Jia, Lü Yang, LIU Yuan, XING Yong-Heng, XU Huan, SONG Yu-Jiang 2012, 33 (9):  1601-1607.  DOI: 10.3724/SP.J.1088.2012.20431 Abstract ( 2238 )   [Full Text(HTML)] () PDF (834KB) ( 1231 )   A new Pt nanocatalyst was synthesized by chemical reduction of K2PtCl4 by ascorbic acid in the presence of a non-ionic surfactant Brij-35 (CH3(CH2)10CH2(OCH2CH2)23OH) in aqueous solution at room temperature. The obtained Pt nanocatalyst was characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction, thermogravimetry (TG), and cyclic voltammetry (CV). The uniform Pt nanocatalyst possesses a globular dendritic morphology with a mean diameter of 36.9 nm. The branches of the globular dendrites are 2-4 nm in diameter and 4–6 nm in length. A simple purification method with multiple water washing was developed to remove Brij-35 and other by-products from the surface of Pt nanocatalyst. TG, EDX, and CV results show that the surface of Pt nanocatalyst after purification is as clean as that of commercial Pt black (fuel cell grade, 99.9%). Compared with commercial Pt black, Pt nanocatalyst demonstrates a higher electrochemical active surface area and significantly improved electrocatalytic activity to oxygen reduction and methanol oxidation.