Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (12): 2358-2365.doi: 10.3866/PKU.WHXB201510135

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Influence of La on CeO2-ZrO2 Catalyst for Oxidation of Soluble Organic Fraction from Diesel Exhaust

Yi. YANG1,Zheng-Zheng. YANG2,Hai-Di. XU3,*(),Bao-Qiang. XU1,Yan-Hua. ZHANG1,Mao-Chu. GONG1,Yao-Qiang. CHEN1,*()   

  1. 1 Key Laboratory of Green Chemistry & Technology of the Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, P. R. China
    2 College of Architecture and Environment, Sichuan University, Chengdu 610064, P. R. China
    3 Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu 610064, P. R. China
  • Received:2015-07-31 Published:2015-12-04
  • Contact: Hai-Di. XU,Yao-Qiang. CHEN E-mail:xuhaidi@scu.edu.cn;nic7501@scu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21173153);National High-Tech Research and DevelopmentProgram of China (863)(2013AA065304)

Abstract:

CeO2-ZrO2 and CeO2-ZrO2-La2O3 catalysts with mass ratios of 60:40 and 60:30:10 were prepared by co-precipitation method, respectively. The catalytic activity in oxidation of the soluble organic fraction (SOF) in diesel exhausts was studied using thermogravimetric-differential thermal analysis (TGDTA). The results indicate that the catalytic activity of the La-modified CeO2-ZrO2 catalyst is better than that of the CeO2-ZrO2 catalyst; the light-off temperature of SOF is 164 ℃, and the weightlessness fastest point temperature is 212 ℃, whereas for CeO2-ZrO2, these temperatures are 168 and 221 ℃, respectively. X-ray diffraction (XRD) shows that modification with La is beneficial to decrease the growth rate of the crystallite size relative to that of CeO2-ZrO2 after high-temperature ageing. N2 adsorption-desorption results suggest that the addition of La enlarges the surface area. O2-temperature-programmed desorption (O2-TPD) and X-ray photoelectron spectroscopy (XPS) show that modification with La increases the amount of chemisorbed oxygen on the CeO2-ZrO2 catalyst. The CeO2-ZrO2-La2O3 catalyst shows better activity and ageing resistance than the CeO2-ZrO2 catalyst.

Key words: CeO2-ZrO2, La-modified CeO2-ZrO2, Soluble organic fraction, Diesel oxidation catalyst, Chemisorbed oxygen

MSC2000: 

  • O643