Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (03): 605-611.doi: 10.3866/PKU.WHXB201212241

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

NOx Storage Performance of Alkaline Earth-Doped Perovskite-Type BaFeO3 Catalysts

LI Feng-Li1, GUO Li1, XIAN Hui1, MENG Ming1, LI Zhi-Jun2, BAO Jun3, LI Xin-Gang1   

  1. 1 Tianjin Key Laboratory of Applied Catalysis Science & Technology, School of Chemical Engineering & Technology, Tianjin University, Tianjin 300072, P. R. China;
    2 State Key Laboratory of Engines, Tianjin University, Tianjin 300072, P. R. China;
    3 National Synchrotron Radiation Laboratory, University of Science & Technology of China, Hefei 230029, P. R. China
  • Received:2012-10-25 Revised:2012-12-24 Published:2013-02-25
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (U1162103, U1232118), National High Technology Research and Development Program of China (863) (2008AA06Z323), Natural Science Foundation of Tianjin, China (11JCYBJC03700), Program for New Century Excellent Talents in University of China (NCET-10-0615), Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education of China (2011-1568), and State Key Laboratory of Engines, Tianjin University, China (K2012-05).

Abstract:

A series of Ba1-xMxFeO3 (M=Mg, Ca, Sr; x=0, 0.1, 0.2) perovskites were prepared by the sol-gel method as NOx storage reduction (NSR) catalysts. The effect of doping with alkaline earth metals (Mg, Ca, and Sr) on the NOx storage and oxidation performance of the BaFeO3 perovskites was investigated. Doping with Mg enhanced the NOx storage capacity (NSC) of the BaFeO3 perovskites in the temperature range 250-400 ℃, the Ba0.8Mg0.2FeO3 perovskite exhibited the best NOx storage performance, which reached its maximum at 350 ℃, with NSC>1200 μmol·g-1 and the NO→NO2 conversion of 53.4%. Compared with BaFeO3, the monodentate nitrate appeared clearly for the Ba0.8Mg0.2FeO3 sample after storing NOx at 250 ℃. The amount of the monodentate nitrate on Ba0.8Mg0.2FeO3 varied with the NOx storage temperature in a similar manner to that of its NSC. Fourier transform infrared (FTIR) spectra indicated that doping with Mg induced an A-site deficient perovskite structure in BaFeO3, which readily generates oxygen vacancies that act as the active sites for NOx adsorption. Moreover, the residual MgO on the catalyst might also improve the NSC of the sample by forming the monodentate nitrate.

Key words: Perovskite, Alkaline-earth metal doping, NOx storage, NO oxidation, Lean-burn

MSC2000: 

  • O643