MnSAPO-34分子筛的制备、表征及其NH3-SCR活性

采用水热合成方法制备含锰的SAPO-34分子筛(MnSAPO-34)催化剂,考察了锰投加量、焙烧温度及晶化时间对催化剂氨选择性催化还原(SCR)氮氧化物反应活性的影响,并通过X射线光电子能谱(XPS)、程序升温还原(TPR)、程序升温脱附(TPD)等多种分析手段对催化剂进行表征.活性测试结果表明,当MnO与P_2O_5的摩尔比n_(MnO)/n_(P_2O_5)=0.1,采用6h晶化时间,550℃焙烧制备的MnSAPO-34分子筛具有最佳SCR活性NO_x转化率接近100%,N_2选择性高于80%.分析结果表明,Mn的引入对分子筛的晶体及多孔结构有较大影响过多的引入会降低结晶度及产生非骨架锰氧...

Full description

Saved in:
Bibliographic Details
Published in物理化学学报 Vol. 31; no. 12; pp. 2375 - 2385
Main Author 陈锋 黄碧纯 杨颖欣 刘小青 喻成龙
Format Journal Article
LanguageChinese
Published 华南理工大学,工业聚集区污染控制与生态修复教育部重点实验室,广州510006 2015
华南理工大学环境与能源学院,广州,510006%华南理工大学环境与能源学院,广州510006
Subjects
Online AccessGet full text
ISSN1000-6818
DOI10.3866/PKU.WHXB201510201

Cover

More Information
Summary:采用水热合成方法制备含锰的SAPO-34分子筛(MnSAPO-34)催化剂,考察了锰投加量、焙烧温度及晶化时间对催化剂氨选择性催化还原(SCR)氮氧化物反应活性的影响,并通过X射线光电子能谱(XPS)、程序升温还原(TPR)、程序升温脱附(TPD)等多种分析手段对催化剂进行表征.活性测试结果表明,当MnO与P_2O_5的摩尔比n_(MnO)/n_(P_2O_5)=0.1,采用6h晶化时间,550℃焙烧制备的MnSAPO-34分子筛具有最佳SCR活性NO_x转化率接近100%,N_2选择性高于80%.分析结果表明,Mn的引入对分子筛的晶体及多孔结构有较大影响过多的引入会降低结晶度及产生非骨架锰氧化物,同时还会降低分子筛的比表面积和孔容,但焙烧温度的降低以及晶化时间的缩短可以提高分子筛的比表面积和孔容.高温焙烧后分子筛表面出现了高氧化态锰物种,以Mn(4+)为主,而提高Mn(3+)的比例则有利于提高催化活性.在适当的合成条件下,Mn的引入可增强分子筛对NO和NH_3分子的吸附,而强吸附态NO及强吸附态NH_3的相互作用可能是催化活性快速提高的原因。
Bibliography:11-1892/O6
Selective catalytic reduction; Nitrogen oxide; Manganese; SAPO-34 molecular sieve;X-ray photoelectron spectroscopy; Temperature-programmed reduction;Temperature-programmed desorption
CHEN Feng, HUANG Bi-Chun, YANG Ying-Xin, LIU Xiao-Qing,YU Cheng-Long (1 School of Environment and Energy, South China University of Technology, Guangzhou 510006, P. R. China; 2 Key Laboratory of the Ministry of Education for Pollution Control and Ecosystem Restoration in Industry Clusters, South China University of Technology, Guangzhou 510006, P. R. China)
A series of MnSAPO-34 molecular sieves were synthesized by a hydrothermal method for selective catalytic reduction (SCR) of NO with NH3 and characterized using X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), and temperature-programmed desorption (TPD). Three factors were studied, including Mn-loading, calcination temperature, and synthesis time. The MnSAPO-34, which was synthesized in 6 h and calcined at 550 ℃ with the Mn-loading (n(Mno)
ISSN:1000-6818
DOI:10.3866/PKU.WHXB201510201