Chinese Journal of Catalysis ›› 2012, Vol. 33 ›› Issue (7): 1125-1132.DOI: 10.1016/S1872-2067(11)60399-9

• Research papers • Previous Articles     Next Articles

Role of CeO2 in Three-Component Au/CeO2/SiO2 Composite Catalyst for Low-Temperature CO Oxidation

ZHANG Huili, REN Lihui, LU Anhui, LI Wencui*   

  1. State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024, Liaoning, China
  • Received:2012-02-14 Revised:2012-03-26 Online:2012-06-21 Published:2012-06-21

Abstract: Hierarchical composite nanostructure composed of Au, CeO2, and SiO2 was fabricated by sequentially depositing ceria nanoparticles through impregnation and calcination, and then gold nanoparticles through a deposition-precipitation method on hierarchical monolithic silica (HMS) with multi-length scale pore structure. The Au/CeO2/HMS composite nanostructure was characterized by X-ray diffraction, temperature-programmed reduction, and diffuse reflectance infrared Fourier transform spectroscopy. The results indicate that the presence of ceria had a significant effect on targeted deposition and stabilization of small metallic gold nanoparticles on the support. The temperature for complete conversion of CO to CO2 over Au/CeO2/HMS is ca. 60 oC at a space velocity of 80000 ml/(g·h). The highly dispersed metallic gold nanoparticles can activate CO and the small ceria nanoparticles supply oxygen in the reaction. The catalytic activity remains considerably stable during 48 h stability testing. The interaction between gold and ceria contributed greatly to CO oxidation and the presence of silica improved the stability of the gold catalyst.

Key words: silica, carbon monoxide oxidation, gold, ceria, stability