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Chinese Journal of Catalysis
2010, Vol. 31, No. 7
Online: 25 July 2010


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High photocatalytic activity of Fe-CNTs/TiO2 composites was firstly presented by Zhang and coworkers in their article on pages 751–758. This high activity can be attributed to that the large CNT network facilitates the electron transfer among TiO2, Fe, and CNTs and effectively inhibits the recombination of electron/hole pairs. The photodegradation ability was further confirmed by COD removal.

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Advances in Research on Novel Microfibrous Structured Catalytic/Adsorbent Packings LING Min;ZHAO Guofeng;CAO Fahai;LU Yong;* 2010, 31 (7):  717-724.  Abstract ( 2457 )   [Full Text(HTML)] () PDF (591KB) ( 1444 )   Process intensification draws a lot of attention because it is working towards energy savings, waste emission reduction, time reduction, and safety improvement. Novel microfibrous structured packings provide a unique combination of large void volume, entirely open structure, large surface-to-volume ratio, high permeability, high heat/mass transfer, and unique form factors, which are central to the notion of increasing the steady-state volumetric reaction rate. The latest progress in the use of microfibrous structured packings in H2 fuel generation and cleanup, air filtration, selective oxidation, electrochemical energy storage, and F-T synthesis has been reviewed. The prospects for the microfibrous structured packings towards process intensification were also presented.

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Alkylation of Naphthalene with Propylene Catalyzed by Aluminum Chloride Immobilized on Al-MCM-41 TANG Hua;JI Min*;WANG Xinkui;HE Min;CAI Tianxi 2010, 31 (7):  725-728.  Abstract ( 2443 )   [Full Text(HTML)] () PDF (323KB) ( 1235 )   AlCl3 catalysts immobilized on mesoporous Al-MCM-41 were prepared by a two step vapor method and their catalytic performance was evaluated for the alkylation of naphthalene with propylene in a slurry bubble column reactor. The physico-chemical properties of the supports and catalysts were characterized by X-ray diffraction, N2 adsorption, and pyridine adsorption infrared spectroscopy. The halide loadings of the catalysts were analyzed by a chemical method. For the alkylation of naphthalene with propylene over AlCl3/Al-MCM-41, pore diameters that match the molecular dimensions of 2,6-diisopropylnaphthalene (2,6-DIPN) and an appropriate amount of [–O–AlCl2] in the catalyst are key to controlling activity and selectivity. The AlCl3 catalyst immobilized on mesoporous H/Al-MCM-41 with a Si/Al ratio of 15 exhibited high activity when the alkylation was carried out at 0.1 MPa and 85 oC for 5 h. A naphthalene conversion of 82.1% and a 2,6-DIPN selectiv-ity of 32.2% were obtained.

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Stability Enhancement of H-Mordenite in Dimethyl Ether Carbonylation to Methyl Acetate by Pre-adsorption of Pyridine LIU Junlong;XUE Huifu;HUANG Xiumin;WU Pei-Hao;HUANG Shing-Jong;LIU Shang-Bin;*;SHEN Wenjie;# 2010, 31 (7):  729-738.  Abstract ( 2910 )   [Full Text(HTML)] () PDF (848KB) ( 1085 )   The carbonylation of dimethyl ether to methyl acetate over H-mordenite (HMOR) and pyridine-modified HMOR was compared. The catalytic stability of HMOR was improved significantly by pyridine pre-adsorption, and a yield of methyl acetate ~30% was still obtained after 48 h on stream at 473 K. In situ infrared spectroscopy and ammonia temperature-programmed desorption revealed that pyridine prefer-entially occupied the acidic sites in 12-membered ring pores but not the acidic sites in 8-membered ring pores. 129Xe NMR studies suggested that the channels of HMOR were blocked by coke in the reaction but those in the pyridine-modified HMOR were not. The acidic sites in the 12-membered ring pores were responsible for the deactivation of HMOR, and the reaction can be directed to occur mainly on the acidic sties in the 8-membered ring pores by the selective adsorption of pyridine in the 12-membered ring pores.

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A Theoretical Investigation of the Structural Properties of Chemically Modified Mo-S-I Nanowires WEN Shuhao;HOU Zhufeng;#;LIU Jianyong;*;He Guozhong 2010, 31 (7):  739-746.  Abstract ( 2715 )   [Full Text(HTML)] () PDF (586KB) ( 816 )   Molybdenum-based materials are good catalysts. The structural properties of a chemically modified MoSI nanowire were investigated by density functional theory calculations. The structural simulation showed that MoSI nanowires have good flexibility and showed hysteresis in its structural evolution. The formation energy, projected density of states, and charge density showed that the chemical modification of MoSI nanowires is possible without losing useful structural and electronic properties useful for applications in catalysis. We suggest potential applications for MoSI nanowire materials in nanoelectronics, nanoelectromechanical, catalysis, and nano-confinement investigations.

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Synthesis, Characterization, and Performance of LaZnxFe1-xO3 Perovskite Nanocatalysts for Toluene Combustion Seyed Ali HOSSEINI;*;Mohammad Taghi SADEGHI;Abdolali ALEMI;Aligholi NIAEI;Dariush SALARI;Leila KAFI-AHMADI 2010, 31 (7):  747-750.  Abstract ( 2283 )   [Full Text(HTML)] () PDF (844KB) ( 1211 )   Nanostructured LaFeO3 and substituted LaZnxFe1-xO3 (x = 0.01, 0.05, 0.1, 0.2, and 0.3) perovskites were synthesized by the sol-gel auto-combustion method and used in the catalytic combustion of toluene. Their structures and surface properties were investigated by X-ray diffraction, Fourier transmission infrared spectroscopy, BET surface area, and scanning electron microscopy. Characterization data revealed that the total insertion of zinc into LaFeO3 takes place when x ≤ 0.1. However, ZnO segregation occurs to some extent, especially at x > 0.1. The performance of these perovskites was evaluated by toluene combustion. The catalytic activity of the catalysts increased substantially with an increase in zinc substitution. These results can be attributed to the cooperative effect between LaZnxFe1-xO3 and the zinc oxide phases. The relative concentration of these phases determines their oxygen activation ability and reactivity.

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Degradation of Rhodamine B by Fe-Carbon Nanotubes/TiO2 Composites under UV Light in Aerated Solution ZHANG Kan;MENG Zeda;OH Wonchun* 2010, 31 (7):  751-758.  Abstract ( 2722 )   [Full Text(HTML)] () PDF (943KB) ( 1806 )   The composites comprising Fe-carbon nanotubes (CNTs) on TiO2 were prepared by a modified sol-gel method and characterized by nitrogen adsorption, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and energy dispersive X-ray analysis. The photocatalytic decomposition of rhodamine B (Rh.B) under UV irradiation and air aeration catalyzed by the composites was measured. The photocatalytic activity of TiO2 nanoparticles was significantly enhanced by the large CNT network that facilitated electron transfer between adsorbed Rh.B molecules and the catalyst substrate and the simultaneous occurrence of the photo-Fenton reaction in the presence of Fe particles. A marked acceleration of the decomposition rate was observed with aeration by flowing air aeration due to the formation of the circulatory photo-Fenton system. Chemical oxygen demand of piggery waste was measured at regular intervals to evaluate the mineralization of wastewater.

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Vapor-Phase Alkylation of Phenol with Tert-butyl Alcohol Catalyzed by H3PO4/MCM-41 Mehran GHIACI*;Behzad AGHABARARI 2010, 31 (7):  759-764.  Abstract ( 2482 )   [Full Text(HTML)] () PDF (134KB) ( 1493 )   The catalytic performance of Al-MCM-41 containing 5?5 wt% H3PO4 was studied for the vapor phase alkylation of phenol with tert-butyl alcohol (TBA) from 383 to 493 K. 4-Tert-butyl phenol was produced as the main product with moderate selectivity. The product distribution depends on the reaction temperature, number of acid sites, and the Br鰊sted to Lewis sites ratios. A lower molar ratio of reactants (TBA/phenol = 2) and a higher space velocity facilitated the production of 4-tert-butyl phenol. The influence of various parameters such as temperature, reactant feed molar ratio, feed rate, and time on stream were investigated for conversion yield and product selectivity.

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Hydrated Alkali Metal Halides as Efficient Catalysts for the Synthesis of Cyclic Carbonates from CO2 and Epoxides ZHOU Xi;ZHANG Yi;YANG Xiangui;YAO Jie;WANG Gongying;* 2010, 31 (7):  765-768.  Abstract ( 2564 )   [Full Text(HTML)] () PDF (262KB) ( 914 )   The synthesis of propylene carbonate from carbon dioxide and propylene oxide using hydrated alkali metal halides as catalysts in the absence of a co-catalyst and a solvent was investigated. The hydrated alkali metal halides showed much higher catalytic activity than the anhydrous alkali metal halides. Sodium iodide dihydrate was found to be the most efficient among them and it gave a 97% yield of propylene carbonate at 120 ?C under 1 MPa within 1.5 h. The corresponding cyclic carbonates from CO2 and other epoxides using sodium iodide dihydrate as catalyst were also successfully synthesized.

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Cu-Zn/Al2O3 Catalyst for the Hydrogenation of Esters to Alcohols YUAN Peng;LIU Zhongyi;ZHANG Wanqing;SUN Haijie;LIU Shouchang* 2010, 31 (7):  769-775.  Abstract ( 2535 )   [Full Text(HTML)] () PDF (543KB) ( 1394 )   A chromium free Cu-Zn/Al2O3 catalyst was used for the slurry phase hydrogenation of palm oil esters to alcohols. Optimal reaction conditions were given. Under the relatively mild conditions of 240 °C and 10 MPa hydrogen pressure, the alcohol yield was above 86.3%, which was much higher than that of conventional Cu-Cr catalysts. Phase changes of the precursor and the calcined and used catalysts were investigated. The role of the active components and surface hydroxyl groups was discussed.

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Low-Temperature Synthesis and Characterization of AlPO-Cristobalite in Ionic Liquid XU Renshun;ZHANG Weiping*;HAN Xiuwen;BAO Xinhe* 2010, 31 (7):  776-780.  Abstract ( 2466 )   [Full Text(HTML)] () PDF (575KB) ( 799 )   AlPO-cristobalite was prepared at low temperature of 80 °C for 30 min in the [bmim]Br ionic liquid. The effects of reaction conditions, such as the amount of organic amine and HF acid, the P/Al ratio, and reaction time, were investigated in detail in the ionothermal synthesis. Powder X-ray diffraction and high-resolution solid-state NMR show that the resultant sample is α-AlPO-cristobalite, and most of the Al and P species are located on the framework and connected by Al–O–P tetrahedron.

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Preparation and Characterization of Rh-Au/冏-Al2O3 Three-Way Nanocatalysts LIU Licheng;ZI Xuehong;DAI Hongxing;ZHAO Zhen;WANG Xinping;HE Hong;* 2010, 31 (7):  781-787.  Abstract ( 2550 )   [Full Text(HTML)] () PDF (688KB) ( 1305 )   Rh/-Al2O3 and Rh-Au/-Al2O3 catalysts were prepared by the ultrasound-assisted membrane reduction (UAMR) and the incipient wetness impregnation (IMP) methods. The properties of the catalysts for three-way catalytic model reactions (CO and C3H8 oxidation, CO + NO, and C3H6+NO+O2) were investigated. The catalysts were characterized by inductively coupled plasma-optical emission spectrometry, H2-O2 titration, N2 adsorption, and transmission electron microscopy. The metal dispersion of the Rh/-Al2O3-UAMR and Rh-Au/ -Al2O3-UAMR catalysts was 45.3% and 40.1% with the metallic surface area of 199.6 and 133.0 m2/g, respectively, and the average metal particle size was smaller than 3 nm. Compared with Rh/-Al2O3-IMP and Rh-Au/-Al2O3-IMP, the Rh/-Al2O3-UAMR and RhAu/-Al2O3- UAMR catalysts possessed much higher catalytic activity for the model reactions. However, the activity of the Rh-Au/-Al2O3- UAMR catalyst was higher than or similar to that of the Rh/-Al2O3-IMP for the model reactions, indicating that the UAMR is a promising method for fabrication of three-way catalysts. The catalysts were deactivated to some extent by hydrothermal pretreatment at 1 000 oC.

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Static Synthesis and Crystallization Mechanism of ZSM-35 Zeolite JU Xiaohua;FAN Fengtao;TIAN Fuping;*;FENG Zhaochi;* 2010, 31 (7):  788-792.  Abstract ( 2382 )   [Full Text(HTML)] () PDF (408KB) ( 1562 )   The pure ZSM-35 zeolite was synthesized in a static hydrothermal system at 220 ºC using cyclohexylamine as the template and silica sol as the Si source. When the initial gel contained a certain amount of K+, the mutual role of K+ and Na+ inhibited the formation of mordenite, and well crystallized product was formed with n(K+)/n(K++Na+) = 0.3. Optimum regions of the synthetic conditions of ZSM-35 zeolite obtained by X-ray diffraction were n(M2O)/n(Al2O3) = 3.2–3.4 and n(SiO2)/n(Al2O3) = 22. The building units in the precursor were identified as five-membered and six-membered silicate rings by UV-Raman spectroscopy. The intensity of the Raman band at 450 cm–1 increased in the beginning of crystallization, and the new bands at 421, 312, and 215 cm–1 appeared with consuming the amorphous gel, indicating that the ring species were turned out to be aggregate through the hydrothermal treatment, and finally formed ZSM-35 zeolite. The strong Raman band at 421 cm–1 should be assigned to the bending vibration of the five-membered silicate ring, and the Raman band at 312 cm–1 might cor-respond to the six-membered silicate ring of ZSM-35 zeolite framework.

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Effect of ZrO2 Addition on the Properties of CuMn2/Al-Ti Monolithic Catalysts for Benzene Catalytic Combustion ZHANG Zhiqiang;HE Zhanfeng;WANG Juanyun;WANG Huanyi;LI Jihua;JIANG Yi;*;CHEN Junhe;ZHANG Xiaoxia 2010, 31 (7):  793-796.  Abstract ( 2339 )   [Full Text(HTML)] () PDF (368KB) ( 964 )   A series of MnOx/Al0.82Ti0.18Ox (Mn/Al-Ti), Cu/Al-Ti, CuMn2/Al-Ti, and CuMn2Zr1.25/Al-Ti monolithic catalysts were prepared by the wet impregnation method. X-ray diffraction, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction, and N2 adsorption were used to characterize the catalysts. The results showed that the addition of ZrO2 in the catalysts increases the specific surface area, component dispersion, oxygen species concentration on the surface, and the redox ability of the catalysts. The monolithic catalysts have high catalytic activity, and the benzene conversion of 91% was obtained at temperature as low as 281 oC.

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Preparation of (Fe, Ni)-Codoped ZnO and Its Photocatalytic Activity for Degradation of Methyl Orange FU Tianhua;GAO Qianqian;LIU Fei;DAI Huajun;KOU Xingming* 2010, 31 (7):  797-802.  Abstract ( 2962 )   [Full Text(HTML)] () PDF (605KB) ( 1553 )   The (Fe, Ni)-codoped ZnO photocatalyst was prepared by a solution method. The product was characterized by X-ray diffraction, scanning electron microscopy, and inductively coupled plasma-atomic emission spectroscopy. The photocatalytic activity of the catalyst was investigated by photodegradation of methyl orange. The effects of initial concentration of methyl orange, photocatalyst amount, and initial pH of methyl orange solution on the photocatalytic efficiency were discussed. The results showed that the (Fe, Ni) co-doping could decrease the crystallinity of ZnO and improve the grain growth of ZnO. The photodegradation experiments showed that (Fe, Ni) co-doping remarka-bly improved the photocatalytic activity of ZnO for methyl orange degradation. The degradation rate of methyl orange solution (10 mg/L) reached 93.5% over (Fe, Ni)-codoped ZnO (0.6 g/L) in 120 min under the irradiation of ultraviolet light.

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Synthesis of UZM-5 Zeolite by a Hydrothermal Method Using Tetraethylammonium Hydroxide-Tetramethylammonium Chloride as Organic Templates LIU Yan;LI Yingxia*;LI Jianwei;CHEN Biaohua 2010, 31 (7):  803-808.  Abstract ( 2612 )   [Full Text(HTML)] () PDF (587KB) ( 1072 )   The synthesis of UZM-5 zeolite by the hydrothermal method in the tetraethylammonium hydroxide (TEAOH)-tetramethylammonium chloride (TMACl) two-organic component system was studied. The products were characterized using X-ray diffraction, infrared spec-troscopy, and thermogravimetry. The crystallization process and growth of UZM-5 zeolite were investigated. The results indicated that the UZM-5 zeolite could be synthesized when the initial mixture was SiO2:(0.16–0.5)Al2O3:(0.4–1.0)TEAOH:(0.06–0.13)TMACl:20H2O. Too high temperature was disadvantageous to the crystallization process. UZM-5 zeolite could be synthesized in the temperature range of 403–423 K. Too long time led to the crystallization of sodalite zeolite. The synthesis of UZM-5 zeolite with silica sol needs 2 days, while silicic acid 4 days and silica gel 5 days. A small amount of Na+ ions resulted in the crystallization of UZM-9 zeolite and had an effect on the phase selectivity.

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Effects of Cr Promoter on Structure and Fischer-Tropsch Synthesis Performance over Fe-Based Catalysts WANG Hulin;YANG Yong;*;WANG Hong;QING Ming;XIANG Hongwei;LI Yongwang 2010, 31 (7):  809-816.  Abstract ( 2560 )   [Full Text(HTML)] () PDF (874KB) ( 938 )   The effects of promoter Cr content in the Fe-based Fischer-Tropsch synthesis (FTS) catalysts on the textural properties, reduction behavior, and phase transformation of the catalysts during reduction and reaction were investigated by N2 adsorption, X-ray diffraction, Mössbauer spectroscopy, X-ray photoelectron spectroscopy, H2 differential thermogravimetric analysis, and CO temperature-programmed reduction over the coprecipitated Fe-based catalysts. The FTS performance of the Fe-based catalysts promoted with Cr was studied in a fixed-bed reactor under the conditions of H2/CO = 2.0, 260–300 oC, 1.5 MPa, and 2 000 ml/(g•h). The results showed that the strong interaction existed between Fe and Cr species by the formation of Fe-Cr solid solution, α-(Fe1-xCrx)2O3. With the increase of promoter Cr content in the Fe-based catalysts, the phases of the catalysts gradually transformed to the Fe-rich phase and Cr-rich phase. Because the Fe-Cr solid solution strongly inhibited the reduction of the catalyst, Cr-promoted Fe-based catalysts exhibited low activity due to its lower extents of both reducibility and carburization. The promoter Cr enhanced the formation of methane and light hydrocarbon products but inhibited the activity of water-gas-shift reaction.

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Effect of Combination Way of Dielectric Barrier Discharge and CuZSM-5 on NOx Removal CHEN Gang;SUN Qi;*;SHI Lei;NIU Jinhai;SONG Zhimin 2010, 31 (7):  817-821.  Abstract ( 2507 )   [Full Text(HTML)] () PDF (325KB) ( 907 )   The effect of the combination way of dielectric barrier discharge (DBD) stage filled with fused silica pellets and a CuZSM-5 catalyst on NOx removal was investigated by one-stage plasma-over-catalyst (POC) and two-stage plasma-followed-by-catalyst (PFC) reactors. In the NO/N2 or NO/C2H4/N2 system, there was a small synergistic effect between DBD plasmas and CuZSM-5 using the one-stage POC and the two-stage PFC reactors. The NOx conversion from the one-stage POC reactor or the two-stage PFC reactor decreased in the NO/O2/N2 system. Under the conditions of the reaction mixture of NO, C2H4, O2, and N2, gas hourly space velocity of 12 000 h–1, the input discharge energy density (Ein) of 155 J/L, and 250 ºC, the NOx conversions in the systems of pure catalyst, pure plasma, plasma-catalyst combination in a one-stage POC reactor, and a two-stage PFC reactor were 39%, 1.5%, 79%, and 52%, respectively. The observed moderately plasma-enhanced NOx conversion in the two-stage reactor was attributed to the stable species such as NO2, CO, and CO2 formed in its first discharge stage. Both short-lived active species (such as N2*, NO*, CH, and CN) and stable species formed from the plasma-induced or plasma-catalytic process in the one-stage reactor may be responsible for the significant synergistic effect between the DBD plasmas and CuZSM-5 catalyst.

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Solid Sulfonic Acid-Promoted Oxidation of Benzyl Alcohol Catalyzed by Isoamyl Nitrite SHENG Xuebin;MA Hong;LI Decai;HE Jing;XU Jie;* 2010, 31 (7):  822-826.  Abstract ( 2662 )   [Full Text(HTML)] () PDF (267KB) ( 944 )   Isoamyl nitrite was employed to catalyze the selective oxidation of benzyl alcohol to benzyl aldehyde using molecular oxygen, in which solid sulfonic acid was used to promote the in situ generation of nitrosonium cation. Solid acid prepared by treating Amberlyst 15 at 300 oC demonstrated the best promotion effect, with which 90% conversion and 97% selectivity for benzyl aldehyde could be achieved at 80 oC under 0.5 MPa for 2 h. The differences of solid acids and their influence on oxidation were investigated by Fourier transform infrared spectroscopy, derivative thermogravimetry, and acid-base titration. Nitrosonium cation was detected by the derivative method using ultravio-let-visible absorption spectrometry.

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Knoevenagel Condensation Catalyzed by Immobilized Ionic Liquids-Proline on SBA-15 SHEN Jiachun;GUO Jianping*;SUN Yanmei;TANG Binyan;CHEN Xiaohua;YIN Dulin* 2010, 31 (7):  827-832.  Abstract ( 2979 )   [Full Text(HTML)] () PDF (497KB) ( 1115 )   The IL-Pro/SBA-15 catalyst was prepared using SBA-15 as the support to immobilize ionic liquid proline, which was synthesized from L-proline. The IL-Pro/SBA-15 catalyst was characterized by FT-IR spectroscopy, thermal gravity analysis-derivative thermogravimetry, N2 adsorption-desorption, X-ray diffraction, and transmission electron microscopy, and the catalytic performance of the catalyst was measured for Knoevenagel reaction. The results showed that the mesoporous structure of SBA-15 was not affected by immobilization; however, the pore diameter, pore volume, and surface area were decreased. Mass loss of the supported ionic liquid occurred at 250–360 oC, and reached the maximum at 310 oC. The Pro-IL/SBA-15 catalyst had higher activity in Knoevenagel reaction of benzaldehyde with malononitrile and gave the corresponding product yield of 94%. The supported catalyst could be easily separated from the reaction system and reused at least seven times without loss of catalytic activity.

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Preparation of Ultrafine Y Zeolite from Spent Fluid Catalytic Cracking Catalyst Powders LIU Xinmei*;LIANG Haining;LI Liang;YANG Tingting;YAN Zifeng 2010, 31 (7):  833-838.  Abstract ( 2700 )   [Full Text(HTML)] () PDF (817KB) ( 1109 )   Ultrafine Y zeolite was successfully prepared by a hydrothermal crystallization method using spent fluid catalytic cracking catalyst powders as the raw material. The sample was characterized by X-ray diffraction, electron microscopy, 29Si and 27Al solid state nuclear magnetic resonance, and particle size analysis. The results showed that the Y zeolite with particle size of 200 nm can be synthesized. The structure of the Y zeolite is strongly influenced by the activation method and the amount of structure directing agent. In the presence of the structure directing agent, the relative crystallinity and the surface area of the Y zeolite increased and the particle size decreased when the spent catalyst is activated by alkali.

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Preparation of Au/SBA-15 and Its Catalytic Activity for CO Oxidation SU Ji-Xin, ZHANG Shen-Ping, MA Li-Yuan, QU Wen, ZHANG Ming-Bo 2010, 31 (7):  839-845.  Abstract ( 2582 )   [Full Text(HTML)] () PDF (915KB) ( 1307 )   The nano-Au catalyst samples were prepared by a facile deposition-precipitation method with SBA-15 as support, and the effects of pretreatment conditions and Au loading on the catalyst activity for CO oxidation were studied. The catalyst samples were characterized by high resolution transmission electron microscopy, N2 adsorption-desorption, X-ray diffraction, ultraviolet-visible diffuse reflectance spec-troscopy, X-ray photoelectron spectroscopy, and inductively coupled plasma-atomic emission spectroscopy. The results showed that the Au particles were highly dispersed in the channels of SBA-15 after reduction and subsequent calcination. The sample pretreated by reduction and calcination exhibited high low-temperature activity and high catalytic activity when the reaction temperature was as high as 500 oC. The catalyst showed good cycle stability and high resistance to sintering.

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Hydrogenation of Aromatic Ketones to Aromatic Hydrocarbons over SiO2-Supported Chitosan Schiff-Base Palladium Catalyst HE Haifeng;GONG Shuwen*;LIU Lijun;CUI Qingxin;YIN Handong 2010, 31 (7):  846-850.  Abstract ( 2615 )   [Full Text(HTML)] () PDF (358KB) ( 948 )   A silica-supported chitosan (CS) Schiff base (SB) palladium complex (SiO2-CS-SB-Pd) was prepared and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and thermal gravimetric analysis. The catalytic performance of the catalyst in hydrogenation of a series of aromatic carbonyl compounds was studied. The influence of the reaction time, reaction temperature, and catalyst amount on hydrogenation of benzophenone was also investigated. The results indicated that the SiO2-CS-SB-Pd catalyst has excellent catalytic activity for hydrogenation of the aromatic aldehydes or ketones into corresponding hydrocarbons at low temperature and under 0.1 MPa. The catalyst is perfectly leach-proof and can be recycled at least two consecutive runs without any obvious loss in activity for the hydrogenation of benzophenone.

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Preparation of Chlorine-Free Cu/AC Catalyst and Its Catalytic Properties for Vapor Phase Oxidative Carbonylation of Methanol WANG Ruiyu;LI Zhong*;ZHENG Huayan;XIE Kechang 2010, 31 (7):  851-856.  Abstract ( 2509 )   [Full Text(HTML)] () PDF (463KB) ( 907 )   Chlorine-free CuO/AC, Cu2O/AC, and Cu0/AC catalysts (AC: activated carbon) were prepared by heat treatment of Cu2(NO3)(OH)3/AC in an inert atmosphere, and their catalytic properties for the direct vapor-phase oxidative carbonylation of methanol to dimethyl carbonate (DMC) were investigated. When the Cu2(NO3)(OH)3/AC was heated at 200 °C, the main copper species on AC was CuO. With the heating temperature rising, the CuO content decreased and the Cu2O content increased on the AC support. The Cu species existed as Cu2O when the heating tempareture was 400 °C and as Cu0 when the heating tempareture was 450 °C. The catalytic activity also increased with the heating temperature rising. This indicated that the CuO, Cu2O, or Cu0 was active, and the catalytic activity increased in the order CuO < Cu2O < Cu0. Under the conditions of 140 °C, CO:MeOH:O2 = 4:10:1, and SV = 5 600 h?1, the Cu0/AC catalyst prepared at 450 °C had excellent catalytic activity, and the methanol conversion, space time yield, and selectivity for DMC reached 11.5%, 261.9 mg/(g•h), and 76.0%, respectively.