催化学报

催化学报 ›› 2006, Vol. 27 ›› Issue (9): 767-771.

• 研究论文 • 上一篇    下一篇

K和Cu部分取代对LaMnO3钙钛矿型催化剂同时去除NOx和碳烟的影响

彭小圣,林赫,上官文峰,黄震   

  1. 上海交通大学燃烧与环境技术中心, 上海 200030
  • 收稿日期:2006-09-25 出版日期:2006-09-25 发布日期:2010-10-28

Effect of Partial Substitution of K and Cu in LaMnO3 on Simultaneously Catalytic Removal of NOx and Soot

PENG Xiaosheng, LIN He, SHANGGUAN Wenfeng, HUANG Zhen*   

  1. Center for Combustion and Environmental Technology, Shanghai Jiao Tong University, Shanghai 200030, China
  • Received:2006-09-25 Online:2006-09-25 Published:2010-10-28

PDF

963

被引次数

82

摘要： 用K部分取代LaMnO3中的La得到La0.8K0.2MnO3, 再用Cu部分取代Mn得到La0.8K0.2CuxMn1-xO3, 采用程序升温反应方法对催化剂同时去除NOx和碳烟的性能进行评价,然后利用XPS从分子水平来解释部分取代对LaMnO3钙钛矿催化剂性能的影响. 结果表明,两种不同取代更有利于催化剂形成钙钛矿型晶体结构,为了保持分子的电中性, K部分取代使得Mn2+转变成Mn3+, 部分转变成Mn4+, 从而使催化剂的活性及选择性大幅度提高. Cu部分取代进一步使部分Mn3+转变成Mn4+, 催化剂的活性有所降低,但由于Cu2+和Mn3+的协同作用,催化剂的选择性得到进一步的提高. 对于同时催化去除NOx和碳烟反应,催化剂中起决定性作用的是表面的Mn3+和Cu2+.

关键词: 钙钛矿, 钾, 铜, X射线光电子能谱, 氮氧化物, 碳烟

Abstract: La0.8K0.2MnO3 and La0.8K0.2CuxMn1-xO3 was prepared by partial substitution of K for La in LaMnO3 and further partial substitution of Cu for Mn, respectively. The catalytic properties of the two catalysts for simultaneous removal of NOx and soot were evaluated through the temperature-programmed reaction technique. X-ray photoelectron spectroscopy (XPS) was adopted to investigate the effect of partial substitution from the aspect of the catalyst composition. The X-ray diffraction results showed that the two kinds of substitution promoted the formation of perovskite. To maintain the electroneutrality, Mn2+ turned to Mn3+ and even some Mn4+ after the partial substitution of K for La, which greatly improved both the activity and the selectivity of the catalysts. The partial substitution of Cu for Mn further promoted the transition of Mn3+ to Mn4+, which deactivated the catalysts a little but improved the selectivity of the catalysts again owing to the synergistic effects of Cu2+ and Mn3+. The XPS results indicated that surface Mn3+ and Cu2+ were the effective ions for the simultaneously catalytic removal of NOx and soot.

Key words: perovskite, potassium, copper, X-ray photoelectron spectroscopy, nitrogen oxide, soot