物理化学学报 >> 2013, Vol. 29 >> Issue (03): 605-611.doi: 10.3866/PKU.WHXB201212241

催化和表面科学 上一篇    下一篇

碱土元素掺杂的BaFeO3钙钛矿型催化剂的NOx储存性能

李锋丽1, 郭丽1, 贤晖1, 孟明1, 李志军2, 鲍骏3, 李新刚1   

  1. 1 天津大学化工学院, 天津市应用催化科学与工程重点实验室, 天津 300072;
    2 天津大学, 内燃机燃烧学国家重点实验室, 天津 300072;
    3 中国科学技术大学, 国家同步辐射实验室, 合肥 230029
  • 收稿日期:2012-10-25 修回日期:2012-12-24 发布日期:2013-02-25
  • 通讯作者: 李新刚 E-mail:xingang_li@tju.edu.cn
  • 基金资助:

    国家自然科学基金(U1162103, U1232118); 国家高技术研究发展计划(863) (2008AA06Z323); 天津市自然科学基金(11JCYBJC03700); 教育部新世纪优秀人才支持计划(NCET-10-0615); 教育部留学归国人员科研启动基金(2011-1568)及天津大学内燃机燃烧学国家重点实验室开放基金(K2012-05)资助项目

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).

摘要:

采用溶胶-凝胶法制备了Ba1-xMxFeO3 (M=Mg, Ca, Sr; x=0, 0.1, 0.2)系列钙钛矿型NOx储存还原(NSR)催化剂, 考察碱金属元素Mg、Ca 和Sr 的掺杂对BaFeO3 钙钛矿NOx 储存和氧化性能的影响. 结果表明, 在250-400 ℃范围内Mg的掺杂提高了BaFeO3钙钛矿的NOx储存性能, 其中以Ba0.8Mg0.2FeO3样品的NOx储存性能最佳, 在温度350 ℃时NOx储存量高达1200 μmol·g-1以上, NO→NO2转化率为53.4%. 与BaFeO3比较,Ba0.8Mg0.2FeO3样品在250 ℃进行NOx储存时就出现了单齿硝酸盐, 并随储存温度的变化而变化, 它的数量与NOx储存量有相同的变化趋势. 傅里叶变换红外(FTIR)光谱结果表明, 与BaFeO3相比, Ba0.8Mg0.2FeO3样品NOx储存量增大的原因在于: 一方面, 形成了具有A位缺陷的钙钛矿结构, 产生大量能够用于储存NOx的氧空位; 另一方面, 未进入钙钛矿晶格的Mg元素可能以碱性氧化物的形式与NOx作用形成了单齿硝酸盐.

关键词: 钙钛矿, 碱土金属掺杂, NOx储存, NO氧化, 稀燃

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