Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (02): 331-337.doi: 10.3866/PKU.WHXB20100201

• CATALYSIS AND SURFACE STRUCTURE • Previous Articles     Next Articles

Structure and Catalytic Property of Ce1-xFexO2 Mixed Oxide Catalysts for Low Temperature Soot Combustion

YAN Dong-Xia, WANG Hua, LI Kong-Zhai, WEI Yong-Gang, ZHU Xing, CHENG Xian-Ming   

  1. Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming 650024, P. R. China; Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, P. R. China
  • Received:2009-09-18 Revised:2009-11-19 Published:2010-01-26
  • Contact: WANG Hua E-mail:wanghuaheat@hotmail.com

Abstract:

A series of Ce1-xFexO2 mixed oxides with different Ce/Fe molar ratios were prepared via hydrothermal method. The effect of Fe content on structure and porperty of the prepared catalysts were characterized by powder X-ray diffraction (XRD), BETspecific surface area, Raman spectroscopy, and H2 temperature-programmed reduction (H2-TPR) techniques. The performance of the catalysts for soot oxidation was evaluated by temperature-programmed oxidation (TPO). Results showed that Fe3+ did not readily dissolve into the ceria lattice and some Fe2O3 highly dispersed on the surface of ceria. Both the formation of Ce-Fe solid solution created sites (oxygen vacancies) for absorbing and activating oxygen, and the presence of surface Fe2O3 strongly improved the aging resistance of the catalysts. With well dispersed surface Fe2O3 and the largest dopant content, the Ce0.8Fe0.2O2 catalyst had the lowest Ti (262 ℃, ignition temperature of soot oxidation) and Tp (314 ℃, temperature of maximumevolution of CO2). Even after aging for long periods at high temperature, the Ti and Tp values for Ce0.8Fe0.2O2 were still relatively low, at 292 and 392 ℃, respectively, indicating high thermal stability.

Key words: Soot combustion, Hydrothermal method, Ce1-xFexO2 mixed oxides, Solid solution, Interaction

MSC2000: 

  • O643