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Chinese Journal of Catalysis
2012, Vol. 33, No. 6
Online: 30 May 2012


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Liu and coworkers in their article on pages 907–913 reported La(Ba)Zr_xCo_1-xO_3-δ catalysts for N₂O decomposition. The introduction of Zr enhanced N₂O conversion via improving surface area, oxygen vacancy, reducibility of the perovskite, and desorption-adsorption properties of oxygen.

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Table of Contents for Vol. 33 No. 6 2012, 33 (6):  0-0.  Abstract ( 1282 )   PDF (1035KB) ( 749 )

Research papers

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Effect of Zirconium in La(Ba)ZrxCo1-xO3-δ Perovskite Catalysts for N2O Decomposition LIU Shuang, CONG Yu, Charles KAPPENSTEIN, ZHANG Tao 2012, 33 (6):  907-913.  DOI: 10.1016/S1872-2067(11)60402-6 Abstract ( 3202 )   [Full Text(HTML)] () PDF (510KB) ( 811 )   Zr-incorporated La(Ba)ZrxCo1-xO3-δ perovskites were prepared by a sol-gel method and used for the catalytic decomposition of the high concentrations of N2O present in propulsion applications. The introduction of Zr significantly enhanced N2O conversion, esp. with x = 0.05 and 0.2 for LaZrxCo1-xO3-δ and BaZrxCo1-xO3-δ, respectively. N2 adsorption, X-ray diffraction, temperature-programmed reduction of H2, temperature-programmed desorption of O2, and oxygen pulse chemisorption techniques were used to characterize the structure and redox and oxygen adsorption property of the perovskites. The increasing of the surface area, modifying of the crystal structure, more facile reducibility of cobalt species, and higher oxygen desorption-adsorption activity due to the introduction of Zr were the reasons for the activity enhancement for N2O decomposition.

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Support Effect in Meerwein-Ponndorf-Verley Reduction of Benzaldehyde over Supported Zirconia Catalysts ZHANG Bo, TANG Ming-Hui, YUAN Jian, WU Lei 2012, 33 (6):  914-922.  DOI: 10.1016/S1872-2067(11)60370-7 Abstract ( 2454 )   [Full Text(HTML)] () PDF (478KB) ( 1027 )   A series of zirconia catalysts supported on Si-MCM-41 and Al-doped MCM-41 (Si/Al = 50) mesoporous molecular sieves, silica, γ-Al2O3, and MgO were prepared by the wet impregnation method. The catalytic activities of these materials in the Meerwein-Ponndorf-Verley reduction (MPV) of benzaldehyde with 2-propanol as reducing agent were investigated, and compared to that of hydrous zirconia. The materials were characterized by X-ray diffraction, nitrogen adsorption-desorption, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectroscopy, and Fourier transform infrared and thermal desorption of pyridine. Loading zirconia on Si-MCM-41, Al-MCM-41, and SiO2 gave improved catalytic activity. This is attributed to a strong interaction of zirconia with the support to form Si–O–Zr bonds, which gave a significant increase in the amount of exposed Zr–OH groups and stronger Lewis acidity as well as an appearance of Brönsted acid sites. The activity of 5%ZrO2/Si-MCM-41 was the highest, followed by those of 5%ZrO2/Al-MCM-41 and 5%ZrO2/SiO2. However, 5%ZrO2/Al2O3 and 5%ZrO2/MgO gave very low catalytic activities. This is ascribed to that the acidities of 5%ZrO2/Al2O3 and the γ-Al2O3 support were similar due to the weak interaction of zirconia with γ-Al2O3, and 5%ZrO2/MgO had no acidity because of the strong interaction between zirconia and MgO.

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One-Pot Four-Component Dakin-West Synthesis of β-Acetamido Ketones Catalyzed by a Vanadium-Substituted Heteropolyacid Reza TAYEBEE, Shima TIZABI 2012, 33 (6):  923-932.  DOI: 10.1016/S1872-2067(11)60379-3 Abstract ( 2530 )   [Full Text(HTML)] () PDF (452KB) ( 1212 )   The multicomponent condensation of an aryl aldehyde, acetyl chloride, acetonitrile, and enolizable ketone as one-pot synthesis of β-acetamido ketones in high yields was investigated using commercial, non-corrosive, and environmentally benign Keggin and Wells-Dawson heteropolyacid catalysts. The best catalyst was H5PW10V2O40. The methodology used simple experimental conditions, and the short reaction times and high yields indicate it is a useful strategy for the large scale synthesis of β-acetamido ketones.

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Effect of Dispersion State and Surface Properties of Supported Vanadia on the Activity of V2O5/TiO2 Catalysts for the Selective Catalytic Reduction of NO by NH3 TANG Fu-Shun, ZHUANG Ke, YANG Fang, YANG Li-Li, XU Bo-Lian, QIU Jin-Heng, FAN Yi-Ning 2012, 33 (6):  933-940.  DOI: 10.1016/S1872-2067(11)60365-3 Abstract ( 2928 )   [Full Text(HTML)] () PDF (497KB) ( 880 )   The effect of the dispersion state and surface properties of supported vanadia on the selective catalytic reduction (SCR) activity of NO over V2O5/TiO2 catalysts was studied by various experimental techniques. The experimental monolayer dispersion capacity of V2O5 on anatase (6.86 VOx/nm2) measured by XRD was almost the same as the concentration of surface vacant sites of anatase estimated by the incorporation model, and it was suggested that isolated vanadia species tend to be dispersed on adjacent octahedral vacant sites. An increase of the NO turnover frequency (TOF) at 300 °C to a maximum (8.3 × 10-3 s-1) at a coverage near half a monolayer was related to the increase of the amount of weak acid sites (Brönsted acid site on each vanadium ion). The TOF decreased rapidly at high VOx coverages because of a decrease of the reducibility of vanadia species and a decrease of the ratio of exposed vanadia species on the surface. The Brönsted acid sites on bridging V–O(H)–V and terminal V–OH of polymeric vanadia species were all active sites in the SCR reaction. The SCR activity of the V2O5/TiO2 catalysts was related to the dispersion state, acidity, and reducibility of the vanadia species.

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Removal of Hexanal by Non-thermal Plasma and MnOx/γ-Al2O3 Combination CHEN Chun-Yu, LIU Tong, WANG Hui, YU Qin-Qin, FAN Jie, XIAO Li-Ping, ZHENG Xiao-Ming 2012, 33 (6):  941-951.  DOI: 10.1016/S1872-2067(11)60391-4 Abstract ( 2563 )   [Full Text(HTML)] () PDF (1087KB) ( 954 )   The removal of hexanal by a combination of a non-thermal plasma and catalyst was studied. There was a synergism between the plasma and γ-Al2O3 that gave a hexanal removal efficiency of 87.1% at 80 °C and 2.8 W discharge power. The removal efficiency was improved to 96.5% when the γ-Al2O3 was loaded with 7.5% MnOx, and a comparable efficiency was also obtained with a Pt/γ-Al2O3 catalyst. The 7.5%MnOx/γ-Al2O3 catalyst was stable over 50 h use during which the removal efficiency did not decline.

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NiMo/γ-Al2O3 Catalysts from Ni Heteropolyoxomolybdate and Effect of Alumina Modification by B, Co, or Ni Radostina PALCHEVA, Luděk KALU?A, Alla SPOJAKINA, Květu?e JIRáTOVá, Georgi TYULIEV 2012, 33 (6):  952-961.  DOI: 10.1016/S1872-2067(11)60376-8 Abstract ( 2308 )   [Full Text(HTML)] () PDF (642KB) ( 1658 )   A hydrotreating NiMo/γ-Al2O3 catalyst (12 wt% Mo and 1.1 wt% Ni) was prepared by impregnation of the support with the Anderson-type heteropolyoxomolybdate (NH4)4Ni(OH)6Mo6O18. Before impregnation of the support, it was modified with an aqueous solution of H3BO3, Co(NO3)2, or Ni(NO3)2. The catalysts were investigated using N2 adsorption, O2 chemisorption, X-ray diffraction, UV-Vis spectroscopy, Fourier transform infrared spectroscopy, temperature-programmed reduction, temperature-programmed desorption, and X-ray photoelectron spectroscopy. The addition of Co, Ni, or B influenced the Al2O3 phase composition and gave increased catalytic activity for 1-benzothiophene hydrodesulfurization (HDS). X-ray photoelectron spectroscopy confirmed that the prior loading of Ni, Co or B increased the degree of sulfidation of the NiMo/γ-Al2O3 catalysts. The highest HDS activity was observed with the NiMo/γ-Al2O3 catalyst with prior loaded Ni.

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Highly Efficient and Environmentally Friendly Preparation of 14-Aryl-14H-dibenzo[a,j]xanthenes Catalyzed by Tungsto-divanado-phosphoric Acid Reza TAYEBEE, Shima TIZABI 2012, 33 (6):  962-969.  DOI: 10.1016/S1872-2067(11)60387-2 Abstract ( 3122 )   [Full Text(HTML)] () PDF (397KB) ( 1182 )   A rapid and efficient procedure for the preparation of various aryl-14H-dibenzo[a,j]xanthenes was reported. The method developed produced excellent yields via one-pot condensation of β-naphthol with various aryl-aldehydes in the presence of Keggin vanadium substituted heteropolyacid, H5PW10V2O40, as catalyst under solvent free conditions. The present methodology therefore offered several advantages but not limited to excellent yields (82%–98%), short reaction times (30–50 min), mild reaction conditions, simple work-up, as well as the utilization of cheap and environmentally benign catalyst in the absence of organic solvents.

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Catalytic Activity and Stability of K/CeO2 Catalysts for Diesel Soot Oxidation DAN Wen-Juan, YANG Li-Hua, MA Na, YANG Jia-Li 2012, 33 (6):  970-976.  DOI: 10.1016/S1872-2067(11)60385-9 Abstract ( 2515 )   [Full Text(HTML)] () PDF (522KB) ( 1046 )   A series of CeO2 supported potassium nitrate and carbonate catalysts were prepared by an impregnation method. The catalytic activity and stability for soot oxidation were investigated by thermal gravimetric/differential thermal analysis and temperature-programmed oxidation cycle techniques. K/CeO2 substantially promotes the catalytic activity, which can be gauged by the lowering of the soot total removal temperature by more than 200 ºC compared with the uncatalyzed reaction. The influence of K precursor on the catalytic activity and stability was addressed. The effect is discussed in terms of the combined functions of K and CeO2, potassium mobility and basicity. For potassium-promoted ceria catalysts the potassium nitrate can preserve the high catalytic activity and good stability through several cycles. When K was present as K2CO3, the activity and stability of catalyst were lower than those of KNO3/CeO2. This behavior is attributed to the higher melting point and stronger basicity of K2CO3 which lead to irreversible adsorption of CO2 generated during soot combustion on the catalyst.

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Regioselective Rhodium-Diphosphine Ligand Catalyzed Hydroformylation of Vinyl Acetate LIANG Hao-Ran, ZHANG Lin, ZHENG Xue-Li, FU Hai-Yan, YUAN Mao-Lin, LI Rui-Xiang, CHEN Hua 2012, 33 (6):  977-981.  DOI: 10.1016/S1872-2067(11)60384-7 Abstract ( 2307 )   [Full Text(HTML)] () PDF (386KB) ( 778 )   Rhodium-catalyzed hydroformylation of vinyl acetate with the use of diphosphine ligands was studied. A high regioselectivity (branched:linear of 99:1) and activity (TOF: 4000 h−1) under optimum conditions were achieved by using a 2,2’-bis(diphenylphosphino methyl)-1,1’-biphenyl ligand. The high turnover number (9200) obtained under mild conditions and stability of the catalyst indicates that it would be useful for industrial vinyl acetate hydroformylation.

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Mild and Highly Efficient Method for Synthesis of 14-Aryl(alkyl)- 14H-dibenzo[a,j]xanthenes and 1,8-Dioxooctahydroxanthene Derivatives Using Pentafluorophenyl Ammonium Triflate as a Novel Organocatalyst Samad KHAKSAR, Nosratollah BEHZADI 2012, 33 (6):  982-985.  DOI: 10.1016/S1872-2067(11)60393-8 Abstract ( 2331 )   [Full Text(HTML)] () PDF (327KB) ( 987 )   A simple and facile synthesis of 14-aryl and alkyl-14H-dibenzo[a,j]xanthenes and 1,8-dioxooctahydroxanthene derivatives has been successfully developed by treatment of β-naphthol or dimedone with aldehydes under mild conditions in the presence of a pentafluorophenyl ammonium triflate (PFPAT) organocatalyst. These catalytic condensation reactions represent green chemical processes and the PFPAT organocatalyst is air-stable, cost-effective, easy to handle, and easily removed from the reaction mixtures.

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Effect of Activation Temperature on Catalytic Performance of CuBTC for CO Oxidation QIU Wen-Ge, WANG Yu, LI Chuan-Qiang, ZHAN Zong-Cheng, ZI Xue-Hong, ZHANG Gui-Zhen, WANG Rui, HE Hong 2012, 33 (6):  986-992.  DOI: 10.1016/S1872-2067(11)60389-6 Abstract ( 3137 )   [Full Text(HTML)] () PDF (757KB) ( 1074 )   CuBTC (BTC = benzene-1,3,5-tricarboxylate), an metal-organic framework (MOF), is active for CO oxidation. The activation temperature has a significant effect on its activity. In-situ diffuse reflectance Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis and differential scanning calorimetry (TGA/DSC) characterization showed that the coordination of CO on the open metal sites occurred during the oxidation reaction, and more open metal sites in the CuBTC framework gave a higher activity.

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Preparation and Properties of Sulfur-Doped Visible-Light Response S-TiO2/SiO2 Photocatalyst CHEN Xiao-Yun, LU Dong-Fang, LIN Shu-Fang 2012, 33 (6):  993-999.  DOI: 10.3724/SP.J.1088.2012.11127 Abstract ( 3135 )   [Full Text(HTML)] () PDF (950KB) ( 4557 )   S-doped visible-light response S-TiO2/SiO2 photocatalyst samples were prepared by a hydrolysis-precipitation method. The photocatalytic activity was investigated by the degradation of phenol. The separability of S-TiO2/SiO2 was determined by sedimentation. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, UV-Vis diffuse reflectance spectroscopy, X-ray diffraction, transmission electron microscopy, and N2 adsorption-desorption were used for catalyst characterization. The results showed that cationic S6+ was incorporated into TiO2 lattice and substituted part of Ti4+. S-TiO2/SiO2 with suitable S-doping exhibited higher activity under ultraviolet light, visible light, and solar irradiation. S-TiO2/SiO2 exhibited better decanting ability and less deactivation. Doped-S can form a new bond of Ti–O–S above the valence band of TiO2 to extend the adsorption edge to 450–550 nm, and can increase amount of surface OH– of TiO2. The addition of SiO2 can form a new bond of Ti–O–Si, beneficial to the high dispersion, and larger surface area of S-TiO2/SiO2.

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Reaction Mechanism for 2-Methylfuran Formation during Hydrogenation of Furfuryl Alcohol Catalyzed by Cu(111) Plane XIA Ming-Yu, CAO Xiao-Xia, NI Zhe-Ming, SHI Wei, FU Xiao-Wei 2012, 33 (6):  1000-1006.  DOI: 10.3724/SP.J.1088.2012.11209 Abstract ( 2549 )   [Full Text(HTML)] () PDF (1357KB) ( 943 )   The reaction mechanism for 2-methylfuran formation during hydrogenation of furfuryl alcohol on Cu(111) plane was investigated by the density functional theory generalized gradient approximation calculations with the slab model. The adsorption energy of furfuryl alcohol was calculated to obtain preferred adsorption sites on Cu(111) plane. Three possible reaction mechanisms were characterized and the reaction potential energy surfaces were computed. The transition states (TSs) were searched with the linear and quadratic synchronous transit (LST/QST) complete search. The results show that the furfuryl alcohol molecule adsorbed on the Cu(111) plane via –OH, and the intermediate ψCH2 and ψCH2O can be obtained by the furfuryl alcohol decomposition. The mechanism for 2-methylfuran formation according to the mechanism C is more probable. The energy barrier of furfuryl alcohol decomposition to form ψCH2 can be significantly reduced by the participation of hydrogen radical. The intermediate of ψCH2 is much easier to obtain the H atom from the furfuryl alcohol, that is the formation routine of the product 2-methylfuran. In the mechanism C, the calculated barrier for the rate-determining step ψCH2O* → ψCHO* + H* is 199.0 kJ/mol. The general reaction is 2ψCH2OH = ψCH3 + ψCHO + H2O.

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Performance of Promoted Rh-Fe/Al2O3 Catalysts for CO Hydrogenation to Ethanol CHEN Wei-Miao, DING Yun-Jie, SONG Xian-Gen, ZHU He-Jun, YAN Li, WANG Tao 2012, 33 (6):  1007-1013.  DOI: 10.3724/SP.J.1088.2012.11215 Abstract ( 2577 )   [Full Text(HTML)] () PDF (472KB) ( 866 )   The effects of Rh and Fe loading, and promoters on CO hydrogenation performance over Rh-Fe/Al2O3 catalysts were investigated, as well as the stability of the catalysts. The results showed that with the increasing of Fe loading, methanol selectivity produced from syngas increased continuously accompanying by the decrease in methane selectivity, but the ethanol selectivity had a maximum value. The addition of alkaline or alkaline earth metals promoted methanol coupling or CO dissociation and insertion, or suppressed hydrogenation ability more or less, as a result, ethanol selectivity enhanced, and methanol selectivity decreased, but hydrocarbon selectivity remained almost unchanged. With CO hydrogenation reaction proceeding, hydrocarbon selectivity decreased, but methanol selectivity increased gradually, unfortunately, ethanol selectivity decreased, and the additions of promoters had little effect on it, probably due to the reduction of Fe species by syngas or decreasing of Rh-Fe interface areas during reaction.

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(CeO2-ZrO2-Al2O3)-(La2O3-Al2O3) Complex Oxide Supported Pd Close-Coupled Catalysts: Effects of Support Calcination Temperature FANG Rui-Mei, HE Sheng-Nan, CUI Ya-Juan, SHI Zhong-Hua, GONG Mao-Chu, CHEN Yao-Qiang 2012, 33 (6):  1014-1019.  DOI: 10.3724/SP.J.1088.2012.11242 Abstract ( 2199 )   [Full Text(HTML)] () PDF (539KB) ( 810 )   A new (CeO2-ZrO2-Al2O3)-(La2O3-Al2O3) complex oxide (CZA-LA) was prepared by the simultaneous co-precipitation method and then it was calcined at different temperatures. The samples calcined at different temperatures were used as support to prepare Pd/CZA-LA catalysts by impregnation and they were further fabricated as close-coupled catalysts in monolith form. The Pd loading of close-coupled catalysts was 2 g/L. The Pd/CZA-LA samples were characterized by N2 adsorption-desorption and X-ray diffraction, and the corresponding catalyst was examined by temperature-programmed reduction of H2 and C3H8 conversion in a simulated automobile exhaust. It was found that both textural properties of the CZA-LA and catalytic performance of the Pd/CZA-LA were remarkably affected by the calcination temperature of CZA-LA support. The new complex oxide samples showed good structural and textural properties and were more resistant to aging at high temperature. The surface area of CZA-LA support decreased with increasing calcination temperature; however, it was still 122 m2/g for S1000 (noted as the CZA-LA support calcined at 1000 °C for 5 h) sample. The pore volume was stable for all of the samples except S600 sample. The catalytic evaluation results showed that the catalytic performance of all fresh catalysts was very good and similar to each other. The light-off temperature (T50 = 310 °C) and complete conversion temperature (T90 = 341 °C) of propane over the Pd/S1000-Aged (noted as the Pd/S1000 catalyst aged at 1000 °C for 5 h) was the lowest among the tested aged catalysts, and the temperature difference, ΔT, between the Pd/S1000-Aged and Pd/S1000-Fresh was as less as 7 °C, indicating that the Pd/S1000-Fresh catalyst showed good catalytic performance for exhaust purification and good resistance to aging. The catalyst may have potential application in the field of advanced Pd close-coupled catalysts.

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Comparison of Automotive Exhaust Purification Performance of Monolith Catalysts Pd/La2O3-Al2O3 and Pd/CeO2-ZrO2-Y2O3 CUI Ya-Juan, HE Sheng-Nan, FANG Rui-Mei, SHI Zhong-Hua, GONG Mao-Chu, CHEN Yao-Qiang 2012, 33 (6):  1020-1026.  DOI: 10.3724/SP.J.1088.2012.11237 Abstract ( 2442 )   [Full Text(HTML)] () PDF (521KB) ( 860 )   Two kinds of support materials, the thermal-stability material La2O3-Al2O3 (LA) and oxygen storage material CeO2-ZrO2-Y2O3 (CZY), were prepared by co-precipitation. Pd/LA and Pd/CZY catalysts were prepared by impregnation and they were further fabricated as three-way catalysts in a monolith form. The Pd/LA and Pd/CZY three-way catalysts thus prepared were evaluated with a simulated automobile exhaust in terms of the relationships of three way performance with the air-to-fuel ratio (A/F) window and with temperatures. The results indicated that the A/F window and the three-way activity of the Pd/CZY catalyst were broader and higher than those of the Pd/LA catalyst. To investigate in more details, several reactions that involved CO in exhaust purification process such as CO oxidation, water-gas shift (WGS) reaction, and NO reduction by CO were examined over Pd/LA and Pd/CZY catalysts. These preliminary studies revealed that the advantages of the Pd/CZY catalyst is mainly from the unique properties of the CeO2 oxygen storage material. Furthermore, it was found that addition of either O2 or NO in reactant gases are favorable for the WGS reaction, which gives some clues for developing an advanced three-way purification process.

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Preparation of MoS2 Nanocatalyst and Its Application in Hydrodesulfurization FAN Xiao-Bing, LIU Fang, YAO Si-Yu, DENG Xian-He, ZHOU Wen-Juan, KOU Yuan 2012, 33 (6):  1027-1031.  DOI: 10.3724/SP.J.1088.2012.10712 Abstract ( 2660 )   [Full Text(HTML)] () PDF (526KB) ( 1238 )   The MoS2 nanocatalyst of 3–5 layers and surface area as high as 71 m2/g was synthesized via a chemical reaction between molybdenum carbonyl and chalcogen. The hydrodesulfurization (HDS) of n-dodecanethiol and dibenzothiophene (DBT) was studied over the MoS2 nanocatalyst. Compared with the commercial MoS2 with lower surface area of 3 m2/g, the MoS2 nanocatalyst showed much higher activity. 100% conversion in HDS at temperatures of 200 °C for dodecanethiol and 280 °C for DBT was achieved under p(H2) = 3.0 MPa.

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Preparation and Catalytic Performance of Phosphotungstic Acid Active Sites Supported on Periodic Mesoporous Organosilica of SBA-15 LIU Cheng, TAN Rong, SUN Wen-Qing, YIN Dong-Hong 2012, 33 (6):  1032-1040.  DOI: 10.3724/SP.J.1088.2012.11259 Abstract ( 2514 )   [Full Text(HTML)] () PDF (857KB) ( 1062 )   A functionalized periodic mesoporous organosilica (PMO), Bis-PImBr-PMO-SBA-15, incorporated with bridging bis-imidazolium ionic liquid moieties was synthesized via a sol-gel procedure. Keggin-type 12-phosphotungstic acid (H3PW12O40? xH2O) was immobilized onto Bis-PImBr-PMO-SBA-15 by the way of anion-exchange, which provided the mesoporous organosilica-supported Keggin-type 12-tungstophosphate catalyst (PW-Bis-PImBr-PMO-SBA-15). X-ray diffraction, N2 adsorption-desorption, transmission electron microscopy, Fourier transform infrared spectroscopy, and thermal analysis results showed that both Bis-PImBr-PMO-SBA-15 and PW-Bis-PImBr-PMO-SBA-15 maintained the typical characteristics of the mesoporous material, and the Keggin-structure of the 12-phosphotungstate anion was intact after immobilization. The catalytic performance of PW-Bis-PImBr-PMO-SBA-15 in the selective oxidation of benzyl alcohol by 30% H2O2 was investigated. The PW-Bis-PImBr-PMO-SBA-15 showed higher catalytic activity than bulk HPW or siliceous SBA-15-supported Keggin-type 12-tungstophosphate catalyst (HPW/SBA-15), the conversion of benzyl alcohol and the selectivity to benzaldehyde were as high as 95% and 94%, respectively. The bis-imidazolium cations were thought to mediate the redox behavior of the Keggin PW12 anions, which in turns enhanced the activity and stability of the catalyst.

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Formation and Function of Formate in the Side-Chain Alkylation of Toluene with Methanol LIN Dan, ZHAO Hui-Min, ZHANG Xiao-Yue, 蓝Dong-Xue , CHUN Yuan 2012, 33 (6):  1041-1047.  DOI: 10.3724/SP.J.1088.2012.11243 Abstract ( 2378 )   [Full Text(HTML)] () PDF (491KB) ( 821 )   KX and NaY zeolites were promoted with alkali carbonates and used in the side-chain alkylation of toluene with methanol. The formation and function of formate were investigated by the infrared spectra of methanol adsorbed on the samples and the catalytic decomposition of isopropanol and methanol. Loading alkali carbonates could improve the catalytic performance of alkali-exchanged faujasite zeolites. During the side-chain alkylation process, various amounts of formate were formed on the surface of the catalysts, especially for K2CO3 promoted KX. These formate species derived from the reaction of carbonates with formaldehyde, the dehydrogenation product of methanol. The formation of formate was closely related to the activity of catalysts in the side-chain alkylation of toluene with methanol. Similar to the promotion of alkali borate, the surface acid/base property of the catalysts was modified by these formate species, and thus generated more effective active sites.

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Synthesis of CuPc/TiO2 Nanotube Composite Materials with Large Surface Area and Their Photocatalytic Activity under Visible Light LIAO Lan, HUANG Cai-Xia, CHEN Jin-Song, WU Yue-Ting, HAN Zhi-Zhong, PAN Hai-Bo, SHEN Shui-Fa 2012, 33 (6):  1048-1054.  DOI: 10.3724/SP.J.1088.2012.20126 Abstract ( 2405 )   [Full Text(HTML)] () PDF (667KB) ( 1078 )   TiO2-based nanotubes (TiO2NT) were synthesized by hydrothermal treatment under the alkaline conditions using P25 as the raw material. Then copper phthalocyanine (CuPc) was chosen as a sensitizer to prepare CuPc modified TiO2NT composite material (CuPc/TiO2NT) by the immersion method. The structure and properties of the samples were characterized, and the photocatalytic activity of pure TiO2NT and CuPc/TiO2NT was also evaluated by degradating rhodamine B under the visible light. The results showed that the TiO2NT had large surface area (362.6 m2/g) and high pore volume (2.039 cm3/g). Even after modified by CuPc, the composite material still kept the high surface area (244.2 m2/g) and pore volume (1.024 cm3/g) for 0.2%CuPc/TiO2NT. The decrease of recombination of photo-injected electrons is expected to appear attributing to the effective charge separation on the interface of TiO2NT and CuPc, improving the transfer efficiency of the photo-excited charges under visible light. Furthermore, the catalyst exhibited obvious visible photocatalytic activity after sensitized by CuPc. As the mole percentage of CuPc was 0.2% in the composite, the degradation rate of rhodamine B over 0.2%CuPc/TiO2NT could reach 59%, increasing by 3.3 times compared with pure TiO2NT after reaction for 180 min.

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Promoting Effect of ZnO or K2O on Cu/SiO2-Al2O3 Catalyst for Vapor-Phase Synthesis of 3-Methylindole from Glycerol and Aniline ZHANG Yue, SUN Wei, SHI Lei, SUN Qi 2012, 33 (6):  1055-1060.  DOI: 10.3724/SP.J.1088.2012.11142 Abstract ( 2500 )   [Full Text(HTML)] () PDF (529KB) ( 743 )   The promoting effect of ZnO or K2O promoter on Cu/SiO2-Al2O3 catalyst for the vapor-phase synthesis of 3-methylindole from glycerol and aniline was studied. The catalyst samples were characterized by X-ray diffraction, transmission electron microscopy, H2 temperature-programmed reduction, NH3 temperature-programmed desorption, and thermogravimetric and differential thermal analysis. The results indicated that the addition of an appropriate amount ZnO or K2O to Cu/SiO2-Al2O3 increased the activity and selectivity as well as the stability of the catalyst remarkably, and ZnO exhibited better efficiency than K2O. ZnO not only reinforced the interaction between the active component and the support, promoted the dispersion of copper particles on the support, but also inhibited the sintering of copper particles during the reaction. K2O could suppress the sintering of copper particles during the reaction to some extent although it did not improve the dispersion of copper particles on the support. The addition of ZnO or K2O to Cu/SiO2-Al2O3 increased the number of weak acid sites in different degrees, which promoted the synthesis of 3-methylindole.

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Periodic Mesoporous Organogold(I)silica Catalysts for Hydration of Alkyne to Methyl Ketone in Water Medium ZHU Feng-Xia, ZHOU Jian-Feng, ZHU Hui-Qin, LI He-Xing 2012, 33 (6):  1061-1066.  DOI: 10.3724/SP.J.1088.2012.20131 Abstract ( 2531 )   [Full Text(HTML)] () PDF (407KB) ( 744 )   A novel periodic mesoporous Au(I) organometalsilica as an active and reusable catalyst for alkyne hydration reaction was synthesized by co-condensation of phenyl silane and organometal bridged silane. Compared with the Au-PPh2-PMO(Ph)-G prepared by the grafting method, the Au-PPh2-PMO(Ph) catalyst showed high dispersion of Au(I) active sites, straightway mesopore channels, and the reduced diffusion limit. During the hydration of terminal alkynes, the Au-PPh2-PMO(Ph) catalyst not only exhibited higher catalytic efficiency than the un-immobilized Au(PPh3)Cl catalyst but also could be used repetitively, showing good potential in industrial application.