Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (06): 1448-1454.doi: 10.3866/PKU.WHXB201204011

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Performance Effect of Pt/MOx-SiO2 (M=Ce, Zr, Al) Catalysts for CO and C3H8 Oxidation

ZHOU Ju-Fa, ZHAO Ming, PENG Na, YANG Zheng-Zheng, GONG Mao-Chu, CHEN Yao-Qiang   

  1. Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, P. R. China
  • Received:2012-01-12 Revised:2012-03-19 Published:2012-05-17
  • Contact: CHEN Yao-Qiang
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21173153) and Science and Technology Department of Science and Technology Support Project of Sichuan Province, China (2011GZ0035).

Abstract: MOx-SiO2 (M=Ce, Zr, Al) mixed oxides with a MOx:SiO2 mass ratio of 1:1 were prepared by co-precipitation. Pt-only diesel oxidation catalysts supported on these mixed oxides were obtained by the incipient wetness method. The catalytic activities in simplified diesel exhaust gas before and after SO2 treatment were analyzed. The catalysts were characterized by X-ray diffraction, N2 adsorption-desorption, NH3/O2/CO2 temperature programmed desorption (NH3/O2/CO2-TPD) and X-ray photoelectron spectroscopy (XPS). The results of NH3-TPD suggested that the surface of the catalysts had multiple acidic sites, and the number of medium-strength acidic sites increased following treatment with SO2. The results of O2-TPD revealed that there were α and β oxygen species in the catalysts, and the amount of O2 desorption decreased for the SO2-treated catalysts. The Pt/Al2O3-SiO2 catalyst exhibited the lowest surface acidity and the largest amount of oxygen desorption. XPS indicated that the binding energy of Pt 4f5/2 decreased when the catalysts were treated with SO2. All the catalysts showed excellent activity for CO and C3H8, and the Pt/ ZrO2-SiO2 catalyst exhibited the best SO2 poisoning resistance, showing the potential for these catalysts to be applied in diesel oxidation.

Key words: Co-precipitation, Mixed oxide, Platinum, Oxidation catalyst, Diesel vehicle, Surface acidity, SO2 poisoning