Acta Phys. -Chim. Sin. ›› 2007, Vol. 23 ›› Issue (05): 664-670.doi: 10.3866/PKU.WHXB20070509

• ARTICLE • Previous Articles     Next Articles

Catalytic Decomposition of N2O over Co-M(M=La, Ce, Fe, Mn, Cu, Cr) Composite Oxide Catalysts

XUE Li; HE Hong   

  1. State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, P. R. China
  • Received:2006-10-08 Revised:2006-12-27 Published:2007-04-28
  • Contact: HE Hong E-mail:honghe@rcees.ac.cn

Abstract: A series of Co-M (M=La, Ce, Fe, Mn, Cu, Cr) composite oxide catalysts were prepared by co-precipitation method and tested in catalytic decomposition of N2O. The results showed that Co-Ce composite oxide with Ce/Co molar ratio of 0.05 (CoCe0.05 catalyst) performed best in the N2O decomposition reaction. The presence of NO and O2 in the feed affected the decomposition rate of N2O over CoCe0.05 by adsorption of nitrate or nitrite species on the active site. The XRD, BET, O2-TPD, and H2-TPR methods were used to characterize the Co-Mmixed catalysts. The analysis results showed that the redox ability of the active site (Co2+) was very important for the decomposition of N2O over these catalysts. The surface decomposition of N2O was accompanied by the oxidation of Co2+ to Co3+, and the desorption of surface oxygen was accompanied by the reduction of Co3+ to Co2+. The addition of other transition metal oxides except CeO2 lowered the redox ability of Co3 +/Co2 +, and thus lowered the catalytic activities for the decomposition of N2O. In addition, the rate-determining step of the catalytic N2O decomposition was also influenced by the addition of various metal oxides.

Key words:

Co3O4, CeO2, Spinel, Catalytic decomposition of N2O, Composite oxide catalyst

MSC2000: 

  • O643