摘要
采用等体积浸渍法制备了的Ce/TiO_2-Al_2O_3(不同摩尔比例)脱硝催化剂。通过性能比较,将最佳Ti/Al比例(2∶1)的Ce/TiO_2-Al_2O_3催化剂用于低温等离子体改性。改性后催化剂的整体性能包括:NO转化率、N_2选择性、稳定性都有了一定的提高,改性前后催化剂在350℃左右的最佳脱硝效率分别为:90.23%,95.67%。此外,由催化剂抗碱金属实验结果可知,改性后的催化剂有更好的抗性,改性前后脱硝效率分别为63.25%,70.54%。并且由XRD,BET,FTIR,UV-vis,NH_3-TPD,SEM,XPS,H_2-TPR一系列表征结果可知,催化剂整体性能的提高与等离子体改性有关,而且低温等离子体改性作用主要体现在两方面:第一、增加了催化剂表面的Ce^(3+)物种,促进了化学吸附氧的生成;第二、催化剂先经等离子体改性再煅烧,有利于增加催化剂表面的Bronsted酸与Lewis酸位点。
The Ce/TiO2-Al2O3 catalysts with different molar ratios of supports were prepared by the incipient-wetness impregnation method,followed by the performance evaluation,to sort out the best ratio of modified sample（ Ti/Al = 2∶ 1）. After the treatment of non-thermal plasma,the whole performances of the catalyst including NO conversion,N2 selectivity and stability were well improved,at about 350 ℃,the optimal NO conversion efficiency is respectively 90. 23%,95. 67% before or after the modification.Besides,according to the results of alkali metal resistance experiment,the modified catalyst has a better resistance and the NO conversion efficiency of treated and untreated samples is respectively 63. 25%,70.54%. Based on the analytical consequence of XRD,BET,FTIR,UV-vis,NH3-TPD,SEM,XPS,H2-TPR,all perfect activity of the Ce/TiO2-Al2O3 catalyst is greatly related with the non-thermal plasma treatment,which is for two cases that it can increase the amount of Ce^（3＋） species to generate more chemisorbed oxygen,the way of modification and then calcination is beneficial for the increment of Bronsted and Lewis acidic sites.
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2017年第10期3466-3474,共9页
Bulletin of the Chinese Ceramic Society
基金
国家重点研发计划子课题项目(2016YFC0209203)
关键词
浸渍法
低温等离子体
抗碱金属
化学吸附氧
改性
impregnation method
non-thermal plasma
alkali metal resistance
chemisorbed oxygen
modification
