Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (11): 2437-2443.doi: 10.3866/PKU.WHXB201309052

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Influence of Reductants on the NOx Storage Performances of the La0.7Sr0.3Co0.8Fe0.2O3 Perovskite-Type Catalyst

XIAN Hui1,2, MA Ai-Jing1, MENG Ming1,3, LI Xin-Gang1,3   

  1. 1 Tianjin Key Laboratory of Applied Catalysis Science & Technology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072;
    2 Pei-Yang Distillation Engineering Limited Company, Tianjin 300457;
    3 The Synergistic Innovation Center of Chemistry and Chemical Engineering of Tianjin, Tianjin 300072
  • Received:2013-07-03 Revised:2013-09-05 Published:2013-10-30
  • Contact: LI Xin-Gang E-mail:xingang_li@tju.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (U1162103), Natural Science Foundation of Tianjin, China (11JCYBJC03700), Program for New Century Excellent Talents in University of China (NCET-10-0615), and the Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University.

Abstract:

A La0.7Sr0.3Co0.8Fe0.2O3 perovskite-type catalyst was synthesized by a sol-gel method. The influence of different reductants (CO, C3H6, and H2) on the NOx storage capacity and NO-to-NO2 conversion of the perovskite was evaluated before and after the NOx storage-reduction (NSR) tests. Our O2temperature programmed desorption findings showed that a large number of oxygen vacancies were generated in the COreduced perovskite. These oxygen vacancies are effective sites for NOx storage. The catalytic tests and Fourier transform infrared (FTIR) spectroscopy results showed that during the NSRtests of catalysts that used CO as the reductant, the catalysts demonstrated excellent NOx storage performance. Further investigations revealed the generation of a new Sr3Fe2O7 phase in the catalyst. This new phase may possess better NOx storage ability than the La0.7Sr0.3Co0.8Fe0.2O3 perovskite. In conclusion, the NOx storage ability of the catalyst was greatly improved after reduction by CO due to an increase in oxygen vacancies and the generation of a Sr3Fe2O7 phase during NSR cycling.

Key words: Lean-burn, Perovskite, NOx, Storage, Reduction, Reductant

MSC2000: 

  • O643