Chemical Research in Chinese Universities ›› 2010, Vol. 26 ›› Issue (1): 98-104.

• Articles • Previous Articles     Next Articles

Gold Catalysts Supported on Crystalline Fe2O3 and CeO2/Fe2O3 for Low-temperature CO Oxidation

LIU Rui-hui1,2, ZHANG Cun-man2,3 and MA Jian-xin2,3*   

  1. 1. School of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China;
    2. Clean Energy Automotive Engineering Center,
    3. School of Automotive Studies, Tongji University, Shanghai 201804, P. R. China
  • Received:2009-03-31 Revised:2009-07-03 Online:2010-01-04 Published:2010-03-29
  • Contact: MA Jian-xin, E-mail: jxma@tongji.edu.cn
  • Supported by:

    Supported by the Henkel Professorship of Tongji University, China.

Abstract:

High active and stable gold catalysts supported on crystalline Fe2O3 and CeO2/Fe2O3 were prepared via the deposition-precipitation method. The catalyst with a Au load of 1.0% calcined at 180 °C showed a CO conversion of 100% at –8.9 °C, while Au/CeO2/Fe2O3 converted CO completely at –16.1 °C. Even having been calcined at 500 °C, Au/Fe2O3 still exhibited significant catalytic activity, achieving full conversion of CO at 61.6 °C. The catalyst with a low Au load of 0.5% could convert CO completely at room temperature and kept the activity unchanged for at least 150 h. N2 adsorption-desorption measurements show that the crystalline supports possessed a high specific surface area of about 200 m2/g. Characterizations of X-ray diffraction and transmission electron microscopy indicate that gold species were highly dispersed as nano or sub-nano particles on the supports. Even after the catalyst was calcined at 500 °C, the Au particles remained in a nano-size of about 6―10 nm. X-ray photoelectron spectra reveal that the supported Au existed in metallic state Au0. The modification of Au/Fe2O3 by CeO2 proved to be beneficial to the inhibition of crystallization of Fe2O3 and the stabilization of gold particles in dispersed state, consequently promoting catalytic activity.

Key words: Gold catalyst; Low-temperature CO oxidation; Iron oxide; Nanoparticle; Additive