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    Chinese Journal of Catalysis
    2006, Vol. 27, No. 10
    Online: 25 October 2006

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    Articles
    Composition of the Surface Intermediate Species in Selective Catalytic Reduction of NOx with Ethylene over Co-ZSM-5
    NIU Jinhai, ZHU Aimin, YANG Xuefeng, SHI Lingling, XU Yong, WANG Xinkui, SHI Chuan
    2006, 27 (10):  837-839. 
    Abstract ( 1693 )   [Full Text(HTML)] () PDF (244KB) ( 730 )  
    A pretreatment-transient reaction product analysis method was applied to study the surface intermediate species in the selective catalytic reduction of NOx with C2H4 over the Co-ZSM-5 catalyst. The reactions of the surface species NCaObHc, formed by the pretreatment of Co-ZSM-5 in a NO/C2H4/O2 gas mixture at 275 ℃, with a NO/O2 flow produce much more N2 than that with a single NO or O2 flow. Apart from the oxygen content that cannot be determined under the experimental conditions, the average atomic ratio of N∶C∶H in the surface species was measured to be about 1.0∶1.8∶5.0 based on the product analysis by mass spectrometry, infrared absorption spectroscopy, and gas chromatography-mass spectrometry.
    Active Structure of Zirconia-Supported Ruthenium Oxide Catalyst for Low-Temperature Oxidation of Methanol to Methyl Formate
    LI Weizhen, LIU Haichao*
    2006, 27 (10):  840-842. 
    Abstract ( 1789 )   [Full Text(HTML)] () PDF (187KB) ( 843 )  
    The oxidation of methanol to methyl formate at low temperature (373 K) over the ZrO2-supported RuOx catalyst was studied. The methanol oxidation rate and product selectivity strongly depend on the RuOx structure, which is changed in the Ru surface density range of 0.2[KG-45x]-[KG-20x]3.8 Ru/nm2. The RuOx structure evolves from isolated RuO2-4 species below 0.4 Ru/nm2 to RuO2 clusters above 1.9 Ru/nm2. Such structural evolution with increasing Ru surface density leads to a decrease in the methanol oxidation rate on per Ru atom and on per exposed Ru atom (i.e. turnover rate). This reveals that RuO2-4 species are more reactive than RuO2 species, which is consistent with the higher reducibility of the RuO2-4 structure. These RuO2-4 species are also more selective than the RuO2 species for the methyl formate formation at similar methanol conversion; a ~96% methyl formate selectivity (at ~15% methanol conversion) was attained at 0.2 Ru/nm2 with predominant RuO2-4 structure. These findings suggest that the highly active and selective RuO2-4 structure is required for achieving high methyl formate productivity.
    Novel MnOx Catalyst for Low-Temperature Selective Catalytic Reduction of NOx with NH3
    TANG Xiaolong1, HAO Jiming2, XU Wenguo1, LI Junhua2
    2006, 27 (10):  843-848. 
    Abstract ( 2132 )   [Full Text(HTML)] () PDF (423KB) ( 822 )  
    A manganese oxide catalyst MnOx was prepared by the low-temperature solid phase reaction method and used for the low-temperature selective catalytic reduction (SCR) of NOx with NH3. The X-ray diffraction results show that MnOx is a mixture of manganese oxides with poor crystallinity, which contains rodlike crystal particles (40~60 nm) and more fine amorphous particles. The BET specific surface area of the MnOx is 150.8 m2/g, more great than that of other unsupported catalysts ever reported, and thus its capability of adsorption is superior. In our experiments, the amount of adsorbed NOx reaches 138.27 μmol/g. The SCR results show that the MnOx is an efficient catalyst for the SCR of NOx at low temperature. A NOx conversion of 98.25% and product selectivity for N2 of 96.6% was obtained at 80 ℃. The addition of 0.01%SO2 and 10%H2O weakens the adsorption of NOx by competition on the catalyst surface, which decreases the NOx conversion to 70% after reaction for 2.5 h. The catalyst activity can be recovered after the removal of SO2 and H2O.
    Reaction Kinetic Model of Gaseous Pollutant Degradation over TiO2/AC Photocatalyst
    ZHANG Jianchen1*, GUO Kunmin2, MA Lan2, ZHAO Hongyang2
    2006, 27 (10):  849-852. 
    Abstract ( 2144 )   [Full Text(HTML)] () PDF (215KB) ( 848 )  
    Titanium dioxide/activated carbon composite photocatalysts were prepared through hydrothermal treatment of titanium dioxide and activated carbon. In a recirculating photocatalytic reactor, the degradation of low concentration butyraldehyde, a gaseous pollutant, over the catalyst was performed. Based on the Langmuir-Hindshelwood equation and some hypotheses, a transient model for the degradation of the butyraldehyde in the recirculating reaction system was proposed. The results obtained from the kinetic model were approximately consistent with the experimental data. This indicated that the photodegradation behavior of gaseous pollutants could be well predicted using the kinetic model.
    Reaction Mechanisms for Gas-Phase Photocatalytic Degradation of Benzene and Butyraldehyde over TiO2/AC Composite Photocatalyst
    ZHANG Jianchen1*, GUO Kunmin2, MA Lan2, ZHAO Hongyang2
    2006, 27 (10):  853-856. 
    Abstract ( 1879 )   [Full Text(HTML)] () PDF (206KB) ( 808 )  
    The TiO2 photocatalyst and TiO2/AC composite photocatalyst were prepared by sol-gel and hydrothermal treatment methods. In a static photocatalytic reactor, the gas-phase adsorption and photocatalytic degradation of benzene and butyraldehyde over the two photocatalysts were studied, and the intermediates and products were detected by gas chromatography. The TiO2/AC composite photocatalyst had stronger adsorption capability and higher photocatalytic activity than the TiO2 photocatalyst. The intermediates and products were the same over TiO2 and TiO2/AC, which indicated that the photocatalytic degradation of benzene (or butyraldehyde) over the two catalysts followed the same mechanism. The possible photocatalytic oxidation pathways were discussed.
    Methanol Steam Reforming over CuZnAl CatalystsDerived from Hydrotalcite Precursor
    TANG Ying, LIU Ye, LU Yong*, ZHU Ping, HE Mingyuan
    2006, 27 (10):  857-862. 
    Abstract ( 1856 )   [Full Text(HTML)] () PDF (457KB) ( 791 )  
    A series of CuZnAl composite oxide catalysts were prepared by calcination of the CuZnAl hydrotalcite precursor at various temperatures and used in the methanol steam reforming reaction. The catalyst calcined at 600 ℃ showed excellent activity and stability for the methanol steam reforming at 250 ℃ and WHSV of 2.5 h-1 with a H2O/CH3OH molar ratio of 1.3 as compared to those calcined at lower or higher temperatures. The results of thermogravimetry, X-ray diffraction, Fourier transform infrared spectroscopy, and temperature-programmed reduction revealed that CuZnAl hydrotalcite was almost completely decomposed at 600 ℃ to form nanosized CuO and the CuAl2O4 spinel phase that played a key role in separating and stabilizing the nanosized Cu and ZnO during the reaction. Increasing the calcination temperature to over 700 ℃ led to severe sintering of CuO and facilitated the formation of the CuAl2O4 spinel phase, causing a significant decrease in the number of active sites. With lower calcination temperatures (300[KG-45x]-[KG-20x]500 ℃), the hydrotalcite precursor was incompletely decomposed to form a (Cu,Zn)AlxOy(CO3)z composite and the associated CuAl2O4 spinel phase was not found. This resulted in the sintering of metallic Cu and ZnO as well during the reaction, thereby decreasing the catalyst activity.
    Preparation of Alumina-Supported Nobel Metal Iridium Catalysts and Their Catalytic Performance for Methanol Decomposition
    ZHANG Xiongwei1, CHU Wei1*, WANG Xiaodong2, YANG Weishen2, SHENG Shishan2, ZHANG Tao2
    2006, 27 (10):  863-867. 
    Abstract ( 1888 )   [Full Text(HTML)] () PDF (271KB) ( 768 )  
    The alumina-supported noble metal iridium catalysts were prepared by the impregnation method. The effect of additive ZrO2, La2O3, or MgO on the catalytic performance was investigated. The supported catalysts were used for the methanol decomposition reaction and were characterized by X-ray photoelectron spectroscopy, temperature-programmed reduction (TPR), temperature-programmed desorption of hydrogen (H2-TPD), and temperature-programmed desorption of carbon monoxide. The promoter addition could remarkably improve the hydrogen selectivity and CO selectivity of Ir/Al2O3 catalyst in the methanol decomposition. La2O3 and ZrO2 were also good promoters for enhancing the methanol conversion. Both hydrogen and CO were held strongly by the MgO-modified Ir/Al2O3 catalyst, which was not favorable for the methanol conversion. The results of TPR and H2-TPD showed that hydrogen spillover existed in the alumina-supported iridium catalyst. The addition of one of the three promoters could significantly enhance the hydrogen spillover effect.
    Synthesis and Characterization of SAPO-11 Molecular Sieve in the Presence of Fluoride Ions
    ZHANG Shengzhen, CHEN Shengli*, DONG Peng, JING Xiujuan, JIANG Kai
    2006, 27 (10):  868-874. 
    Abstract ( 1857 )   [Full Text(HTML)] () PDF (482KB) ( 880 )  
    The silicoaluminophosphate SAPO-11 molecular sieve was synthesized by the hydrothermal crystallization method in the presence of fluoride ions and characterized by X-ray diffraction, scanning electron microscopy, N2 adsorption, Fourier transform infrared reflectance spectroscopy, and temperature-programmed desorption of adsorbed NH3. The results showed that the addition of HF increased the crystallization rate of SAPO-11 and decreased the crystallization time considerably, and hence the relative crystallinity of SAPO-11 increased whereas the defects in the crystal lattice decreased. Prismatic crystal aggregates of 1~3 μm in length were obtained in the presence of HF during the preparation of SAPO-11, whereas spherical aggregates with diameters of 8~10 μm were synthesized without using HF. The SAPO-11 synthesized in the presence of HF possessed lower BET surface area, higher pore volume, and larger mean pore diameter and crystal size than that prepared without HF. The addition of HF into the synthesis system decreased the amount of surface acid sites and increased the acidic strength of B acid sites on SAPO-11, while the amount of L acid sites kept constant.
    Synthesis and Catalytic Kinetics of Tellurium-Modified Hyaluronic Acid with Glutathione Peroxidase Activity
    ZHANG Boxun1, CHEN Zhibo1, AN Yang3, PENG Qinglin1, CHEN Jia1, ZHANG Jianguo2, LIU Lanying1*
    2006, 27 (10):  875-879. 
    Abstract ( 1797 )   [Full Text(HTML)] () PDF (339KB) ( 988 )  
    A novel mimic TeHA was synthesized by modifying hyaluronic acid (HA) with tellurium, whose function is similar to that of glutathione peroxidase (GPX). The structure of TeHA was characterized by means of infrared spectroscopy and nuclear magnetic resonance spectroscopy, showing that the target Te is located at -CH2OH of the N-acetyl-D-glucosamine of HA. The activity of TeHA is 163.6 U/μmol according to Wilson′s method. In contrast to other mimics, TeHA displays a high activity. Moreover, TeHA can use many hydroperoxides as substrates, such as H2O2, cumenyl hydroperoxide, and tert-butyl hydroperoxide, and cumenyl hydroperoxide is the optimal substrate. A ping-pong mechanism was deduced for the reduction reactions catalyzed by TeHA according to the steady-state kinetic studies.
    Photocatalytic Hydrogen Evolution from Water over Layered K-Fe-Ti Metal Oxides
    SANG Lixia1*, LI Qunwei1, MA Chongfang1, XU Lixian1, SUN Jihong2, DAI Hongxing2, HE Hong2
    2006, 27 (10):  880-884. 
    Abstract ( 1807 )   [Full Text(HTML)] () PDF (378KB) ( 786 )  
    Layered K-Fe-Ti metal oxide catalysts with different K∶Fe∶Ti molar ratios were synthesized by the conventional solid-state reaction and characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV-Vis diffuse reflectance spectroscopy. There were two kinds of crystal structure in the catalysts, tetragonal and orthorhombic symmetry phases, which is related to the amount of interlayer K+ ions and solid-state reaction temperature. In the UV-Vis diffuse reflectance spectra of the catalysts, the absorption peaks in the visible region appeared, and the absorption peaks at 400~550 nm were attributed to the octahedral Fe3+ species. Moreover, the excessive amount of Fe3+ ions in the materials could increase the isolated Fe2O3 species but could not affect the crystal structure of catalyst. In the presence of the electron donor, H2C2O4, the catalyst with the orthorhombic crystal phase exhibited higher photocatalytic activity for water splitting than that with the tetragonal crystal phase, but the latter showed better reaction stability for the hydrogen evolution from water.
    Performance of Anode-Supported Single-Chamber Solid Oxide Fuel Cells
    AI Gang1, LU Zhe1*, WEI Bo1, HUANG Xiqiang1, CHEN Kongfa1, SU Wenhui1,2,3
    2006, 27 (10):  885-889. 
    Abstract ( 1773 )   [Full Text(HTML)] () PDF (415KB) ( 1054 )  
    An anode-supported single-chamber solid oxide fuel cell (SC-SOFC) with dense yttria-stabilized zirconia film as the electrolyte was fabricated by the slurry spin coating technique. The single cell exhibited high performance when operated in a mixture of methane, nitrogen, and oxygen. At 700 ℃, the open current voltage and maximum power density were 1 V and 398 mW/cm2, respectively. The ohmic resistance was as small as 0.097 Ω•cm2, being 6.4% of the electrode polarization resistance only. Therefore, the anode-supported SC-SOFC with optimized electrode materials is very promising.
    Preparation, Characterization, and Photocatalytic Activity of Visible Light Driven Chlorine-Doped TiO2
    CHEN Heng, LONG Mingce, XU Jun, CAI Weimin*
    2006, 27 (10):  890-894. 
    Abstract ( 2112 )   [Full Text(HTML)] () PDF (389KB) ( 932 )  
    A novel chlorine-doped titanium dioxide catalyst with visible light response was prepared by hydrolysis of tetrabutyl titanate in hydrochloric acid. The catalyst samples were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflectance spectroscopy. The results showed that the doped element of Cl lowered the temperature of phase transformation of TiO2 from amorphous to anatase and from anatase to rutile. The absorption edge of chlorine-doped TiO2 calcined at 300 ℃ shifted to the visible light region. XPS results proved that chlorine existed in the TiO2 crystal lattice as an anion. The photocatalytic degradation of phenol showed that under visible light (λ>400 nm) irradiation, the chlorine-doped TiO2 photocatalyst calcined at 300 ℃ displayed the best performance, and the degradation ratio of phenol was 42.5% after 120 min.
    Preparation and Catalytic Performance of Cr2O3-ZnO Catalyst for Methanol Steam Reforming
    CAO Weiqiang, CHEN Guangwen*, CHU Jiansheng, LI Shulian, YUAN Quan
    2006, 27 (10):  895-898. 
    Abstract ( 2017 )   [Full Text(HTML)] () PDF (318KB) ( 688 )  
    The Cr2O3-ZnO catalyst for methanol steam reforming was prepared by the co-precipitation method and characterized by means of X-ray diffraction and N2 adsorption. The catalytic performance for methanol steam reforming was evaluated using a stainless steel microchannel reactor. The addition of Cr to ZnO resulted in the formation of ZnCr2O4 spinel and promoted the activity and stability of the catalysts, although the BET surface area decreased. However, raising the Cr content also led to an increase in the CO selectivity. The Cr2O3-ZnO catalysts with the Cr content of 5.3%[KG-45x]-[KG-20x]17.6% calcined at above 500 ℃ exhibited better catalytic performance than that calcined at 400 ℃.
    Effect of Ni Promoter on Dibenzothiophene Hydrodesulfurization Performance of Molybdenum Carbide Catalyst
    JIN Guangzhou1,2*, ZHU Jianhua1, FAN Xiuju2, SUN Guida2, GAO Junbin2
    2006, 27 (10):  899-903. 
    Abstract ( 2071 )   [Full Text(HTML)] () PDF (303KB) ( 1253 )  
    Molybdenum carbide and nickel-molybdenum carbide catalysts were prepared by temperature-programmed reduction using a CH4/H2 gas mixture to carburize molybdenum trioxide and nickel-molybdenum oxide. X-ray diffraction patterns showed that the crystals were β-Mo2C and Ni-Mo2C, respectively. The effects of nickel promoter on the preparation of molybdenum carbide and its catalytic performance for hydrodesulfurization of dibenzothiophene (DBT) were studied. The results indicated that adding a proper amount of the nickel promoter could decrease the carburizing temperature, increase the BET surface area, and markedly promote the DBT hydrodesulfurization activity of the molybdenum carbide catalysts. When the Ni/Mo atom ratio was 0.3, the synergistic interaction between Ni and Mo was the maximum. The hydrodesulfurization conversion of DBT over the Ni-Mo2C catalyst reached 96.25% under the reaction conditions of 330 ℃, 3.0 MPa, and space velocity 8 h-1, and the conversion was 1.57 times higher than that of Mo2C.
    Role of CeO2 Promoter in Co/SiO2 Catalyst for Fischer-Tropsch Synthesis
    DAI Xiaoping, YU Changchun*, LI Ranjia, SHI Haibo, SHEN Shikong
    2006, 27 (10):  904-910. 
    Abstract ( 1922 )   [Full Text(HTML)] () PDF (621KB) ( 936 )  
    Fischer-Tropsch (FT) synthesis is gaining more and more interest because of the need of high purity diesel fuels and lubricating oil. The cobalt-based catalyst is well known for its activity in the FT reaction. The addition of a small amount of ceria to the Co/SiO2 catalyst can increase the turnover rate and C5+ selectivity, especially promote the formation of high hydrocarbons, but the role of ceria is still of controversy. In this study, the CeO2-promoted Co/SiO2 catalyst was prepared by the incipient wetness impregnation method and characterized by X-ray diffraction, temperature-programmed reaction, X-ray photoelectron spectroscopy, scanning electron microscopy, H-D isotopic exchange, and D2 pulse experiment. The results showed that adding a small amount of ceria improved the dispersion of cobalt, decreased the electron density of the cobalt particle, and enhanced the dissociation of CO on the catalyst surface. This might be due to the new catalytic active sites at which CO bonded to the Co atom with its carbon atom and to the adjacent partially reduced cerium oxide with its oxygen atom. The D2 pulse in the FT reaction showed that the addition of ceria to Co/SiO2 increased the concentration of surface active carbon species (-CH2-), the chain growth probability, and the selectivity for long chain hydrocarbons, which favored the formation of the high value diesel oil and lubricating oil.
    Influence of α-Al2O3 Properties on CO Catalytic Coupling Reaction over Pd Catalyst
    LIN Qian, ZHAO Xiuge, BI Wei, XIAO Wende*
    2006, 27 (10):  911-915. 
    Abstract ( 2221 )   [Full Text(HTML)] () PDF (273KB) ( 762 )  
    A series of Pd/α-Al2O3 catalysts for the CO coupling reaction were prepared with α-Al2O3 from five different sources. The influence of impurities, specific surface area, and pore structure of the support on the catalyst activity was studied. X-ray diffraction and energy dispersive X-ray analysis results confirm the existence of various impurities in three α-Al2O3 samples due to their different production methods. The sodium oxides and γ-Al2O3 in the support decrease the catalyst activity from 45%CO conversion to 10%. The N2 adsorption result shows that the specific surface area and pore volume of the support are not as much important as the pore distribution for the activity of Pd/α-Al2O3, and the double pore structure of the support is necessary for preparing high activity catalysts. Moreover, the results of CO chemical adsorption on the five catalysts show that the CO coupling reaction does not need many active sites to get a high CO conversion.
    Catalytic Oxidation of Dimethyl Ether to Dimethoxymethane over MnCl2-H4SiW12O40/SiO2 Catalyst
    ZHANG Qingde1,2, TAN Yisheng1, YANG Caihong1, LIU Yuqin1, HAN Yizhuo1*
    2006, 27 (10):  916-920. 
    Abstract ( 2158 )   [Full Text(HTML)] () PDF (298KB) ( 704 )  
    The H4SiW12O40/SiO2 heteropolyacid catalyst for the catalytic oxidation of dimethyl ether to dimethoxymethane was prepared by the impregnation method. MnCl2, SnCl4, and CuCl2 were used to modify the catalyst to improve its activity and selectivity. The catalytic oxidation reaction was carried out in a continuous flow fixed-bed reactor. H4SiW12O40/SiO2 is active for the dimethyl ether oxidation, but the selectivity for dimethoxymethane is as low as 4.8%. Modification of H4SiW12O40/SiO2 with 5% MnCl2 significantly improves the dimethoxymethane selectivity up to 27.9% at 633 K, while SnCl4- and CuCl2-modified catalysts give dimethoxymethane selectivities of 16.4% and 0.4%, respectively, under the same conditions. The effects of the MnCl2 content (2%-20%) and reaction temperature (573-633 K) on the reaction were investigated. A dimethyl ether conversion of 8.6% and a dimethoxymethane selectivity of 36.3% were obtained under the optimum conditions of 593 K and 5% MnCl2 content. X-ray diffraction patterns of the catalysts show that MnCl2 and H4SiW12O40 interact and are dispersed uniformly on the support. Infrared spectra demonstrate that the Keggin structure of H4SiW12O40 remains almost unchanged over the modified catalyst. Ammonia temperature-programmed desorption profiles indicate that MnCl2 modification reduces the acidity of H4SiW12O40/SiO2 by decreasing the acid center numbers.
    Hydrogenation of Pyridine and Its Derivatives over Supported Nanometer Noble Metal Catalysts
    XUE Fang1, LIN Qi1,2, YANG Chaofen1, LI Xianjun1, CHEN Hua1*
    2006, 27 (10):  921-926. 
    Abstract ( 2323 )   [Full Text(HTML)] () PDF (409KB) ( 1122 )  
    The highly dispersed supported noble metal catalysts were prepared and their catalytic performance for hydrogenation of pyridine was investigated. The results indicated that the 5%Ru/C catalyst exhibited the highest activity compared with Pd/C, Pt/C and Ir/C. The order of catalyst activity was Ru/C>Pd/C>Pt/C>Ir/C. Under the optimum reaction conditions of 100 ℃, p(H2)=3.0 MPa, and Ru/pyridine molar ratio=2.5/1?000, pyridine could be completely converted to piperidine with a 100% selectivity over 5%Ru/C. Furthermore, the activity and selectivity of 5%Ru/C did not decrease significantly after 5 cycle runs. The activity of bimetallic catalysts Ru-Pd/C and Ru-Ir/C was slightly lower than that of Ru/C, whereas the activity of Ru-Co/C was much lower than that of Ru/C. The reduced 5%Ru/C catalyst was characterized by high resolution transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The results showed that ruthenium was reduced to zero valence and the average particle diameter of Ru crystallites was smaller than 5 nm. The hydrogenation reactivity of pyridine and its derivatives was in the order pyridine≈2-methylpyridine>2,6-dimethylpyridine>3-methylpyridine>4-methylpyridine>3,5-dimethylpyridine>2-methoxy-pyridine, indicating that the electron factor played an important role in the reaction process.
    Effect of Silica Promoter on Properties of Cu-ZnO/HZSM-5 Catalyst for CO2 Hydrogenation to Dimethyl Ether
    WANG Jiyuan, ZENG Chongyu*, WU Changzi
    2006, 27 (10):  927-931. 
    Abstract ( 1918 )   [Full Text(HTML)] () PDF (431KB) ( 775 )  
    The effects of the silica promoter on the properties of the Cu-ZnO/HZSM-5 catalyst were investigated by means of X-ray diffraction, temperature-programmed reduction, and X-ray photoelectron spectroscopy. The addition of a small amount of silica (e.g. 1.0%) to Cu-ZnO/HZSM-5 could greatly improve the CO2 conversion and the selectivity for dimethyl ether, and decrease the selectivity for CO, and increase the catalytic stability of the catalyst. However, a large amount of silica caused a decrease in the catalytic activity. The presence of SiO2 led to the changes of phase structure in calcined samples, improved the dispersion of CuO and ZnO, and increased the reduction temperature of CuO. The silica added could suppress the crystallization of Cu0 and ZnO during the reaction, stabilize the active Cu0, and thus improve the activity and stability of the catalyst.
    Synthesis of PtRu Nanowires and Their Catalytic Activity in the Anode of Direct Methanol Fuel Cells
    SUN Shiguo1,3, XU Hengyong1, TANG Shuihua1, GUO Junsong1, LI Huanqiao1, CAO Lei1 , ZHOU Bing2, XIN Qin1, SUN Gongquan1*
    2006, 27 (10):  932-936. 
    Abstract ( 1932 )   [Full Text(HTML)] () PDF (395KB) ( 850 )  
    PtRu nanowires and nanorods with different alloy extents and aspect ratios were synthesized by impregnating and reducing Pt and Ru precursors using SBA-15 and MCM-41 mesoporous molecular sieves as the template, respectively. The results of X-ray powder diffraction, transmission electron microscopy, cyclic voltammetry, and linear sweep voltammetry demonstrated that the PtRu nanowires synthesized using SBA-15 as the template had a higher alloy extent, larger aspect ratio, and better electrocatalytic activity in a methanol and sulfuric acid solution than the PtRu nanorods synthesized using MCM-41 template. The effects of alloy extent and aspect ratio of PtRu electrocatalysts on the catalytic activity and anode performance of direct methanol fuel cells were discussed.