高等学校化学学报

高等学校化学学报 ›› 2012, Vol. 33 ›› Issue (11): 2532.doi: 10.7503/cjcu20120079

• 物理化学 • 上一篇    下一篇

制备方法对Mn-Ce/ZSM-5催化剂低温选择性催化还原NO性能的影响

贺丽芳1, 刘建东1, 黄伟2, 李哲1   

  1. 1. 太原理工大学化学化工学院, 太原 030024;
    2. 太原理工大学煤科学与技术教育部和山西省重点实验室, 太原 030024
  • 收稿日期:2012-01-19 出版日期:2012-11-10 发布日期:2012-10-15
  • 通讯作者: 李哲,男,博士,教授,博士生导师,主要从事多相催化科学与技术方面的研究.E-mail:lizhe@tyut.edu.cn E-mail:lizhe@tyut.edu.cn
  • 基金资助:

    国家自然科学基金(批准号: 21073131)和山西省科技攻关项目(批准号: 20100321023)资助.

Effect of Preparation Methods on Performance of Mn-Ce/ZSM-5 Catalyst for Low-temperature Selective Catalytic Reduction of NO

HE Li-Fang1, LIU Jian-Dong1, HUANG Wei2, LI Zhe1   

  1. 1. College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, China;
    2. Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, China
  • Received:2012-01-19 Online:2012-11-10 Published:2012-10-15

PDF (PC)

被引次数

33

摘要：

采用浸渍法、氨水共沉淀法和机械混合法制备了Mn-Ce/ZSM-5催化剂, 并研究了其对氨选择性催化还原(NH\-3-SCR)NO反应的催化性能. 结果表明, 采用氨水共沉淀法制备的Mn-Ce/ZSM-5催化剂显示出优越的NH3-SCR催化活性, 不仅具有好的低温催化活性和宽的反应温度窗口, 而且具有高的热稳定性. 铈的含量对催化活性也存在着明显的影响. 采用X射线衍射(XRD)、 X射线光电子能谱(XPS)和等离子体发射光谱(ICP)等技术对不同方法制备的Mn-Ce/ZSM-5催化剂的体相和表面结构进行了表征. 结果发现, Mn-Ce/ZSM-5催化剂中Ce主要以Ce4+的形态出现, 并与锰有较强的协同作用. Mn以多种氧化物的形态共存, 采用氨水共沉淀法制备更有利于低价态的锰氧化物Mn2O3, Mn3O4等的形成, 并且更易于氧物种(O1s)在催化剂表面富集, 这可能是导致氨水共沉淀法所制备的Mn-Ce/ZSM-5样品活性最佳的原因.

关键词: Mn-Ce/ZSM-5, 低温催化剂, 氮氧化物, 选择性催化还原

Abstract:

Mn-Ce/ZSM-5 catalysts for selective catalytic reduction(SCR) of nitric oxide with NH3 were prepared by co-impregnation(CI), co-precipitation(CP) and physical mixture(PM) methods. The Mn-Ce/ZSM-5 catalyst prepared by co-precipitation method exhibited excellent SCR performance, it had not only good SCR activity and broad temperature window, but also high thermal stability. The effect of Ce content on SCR activity of Mn-Ce/ZSM-5 catalyst was obvious. The structure and phase of the Mn-Ce/ZSM-5 catalysts prepared by different methods were investigated. The results show that Ce exist mainly in Ce4+ in Mn-Ce/ZSM-5 catalyst, and CeO2 may strongly interact with MnOx. Many kinds of Mn phases exist in Mn-Ce/ZSM-5 catalyst. The sample prepared by co-precipitation method possesses more MnOx phases of lower bond valence such as Mn2O3 and Mn3O4. It can make oxygen species(O1s) easily enriched on the surface of the Mn-Ce/ZSM-5 catalyst. These factors may lead to the best catalytic activity of the Mn-Ce/ZSM-5 prepared by co-precipitation.

Key words: Mn-Ce/ZSM-5, Low-temperature catalyst, NOx, Selective catalytic reduction

中图分类号: 

TrendMD: