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Chem. J. Chinese Universities ›› 2006, Vol. 27 ›› Issue (5): 914.doi:

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Composition of Cu/SiO2 Nanometer Aerogel and Its Catalytic Properties for CO Oxidation

ZHAO Hui-Zhong1,2*, GE Shan1, WANG Hou-Zhi 1,2, ZHANG Wen-Jie2   

  1. 1. The Hubei Province Key Laboratory of Ceramics and Refractories, Wuhan University of Science and Technology, 430081;
    2. Center of Nanomaterials and Technology, Wuhan University of Science and Technology, Wuhan 430081, China
  • Received:1900-01-01 Revised:1900-01-01 Online:2006-05-10 Published:2006-05-10
  • Contact: ZHAO Hui-Zhong

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Abstract:

A series of Cu/SiO2 nanometer aerogel catalysts with different molar ratios of Cu to Si were prepared by sol-gel-SCFD methods and characterized by TEM, XRD, physisorption analysis instrument, micro-reactor and gas chromatogram. It was found that SiO2 was amorphous and Cu was highly dispersed on the SiO2 particles, and the structure consists of mesopores. The BET analysis indicates that the samples have a high specific surface area more than 140 m2·g-1. The catalytic activities investigation show that the content of copper and the different phases of reactive species all affected the activities of the samples. When n(Cu)/n(Si)=2, the temperature of entire oxidation of CO upon the sample was reduced to 210 ℃. After calcination at a low temperature, the nanometer particles of Cu and Cu2O transformed into nanometer CuO, the temperature of CO full conversion to CO2 was further decreased. Adding small amounts of cerium dopant into the composition can change the reactive species from CuO, Cu2O to Cu, which can further reduce the temperature of tstart, t50 and t90 of the samples. The kinetics research demonstrates that essential of the decrease of the CO oxidation temperature was the decrease of activation energy of CO oxidation reaction.

Key words: Nanometer aerogel catalyst; Microstructure; Catalytic activity

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