文献类型：期刊文献

英文题名：Alkaline modification of ZSM-5 catalysts for methanol aromatization: The effect of the alkaline concentration

作者：Wei, Zhenhao[1];Xia, Tengfei[1];Liu, Minghui[1];Cao, Qingsheng[1];Xu, Yarong[1,2];Zhu, Kake[1];Zhu, Xuedong[1]

机构：[1]E China Univ Sci & Technol, Sch Chem Engn, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]PetroChina Co Ltd, Urumchi Petrochem Co, Res Inst, Urumqi 830019, Peoples R China

年份：2015

卷号：9

期号：4

起止页码：450

外文期刊名：FRONTIERS OF CHEMICAL SCIENCE AND ENGINEERING

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000365759300004)】；

基金：We gratefully acknowledge funding from Technology Admin. Department of PetroChina Company Limited (No. 2012A-2204-01).

语种：英文

外文关键词：ZSM-5; alkaline treatment; dealumination; desilication; mesopores; methanol; aromatics

摘要：The effects of alkaline treatment on the physical properties of ZSM-5 catalysts and on their activities for methanol to aromatics conversion have been investigated. A mild alkaline treatment (0.2 and 0.3 mol/L NaOH) created mesopores in the parent zeolite with no obvious effect on acidity. The presence of mesopores gives the catalyst a longer lifetime and higher selectivity for aromatics. Treatment with 0.4 mol/L NaOH decreased the number of Bronsted acid sites due to dealumination and desilication, which resulted in a lower deactivation rate. In addition, more mesopores were produced than with the mild alkaline treatment. As a result, the lifetime of the sample treated with 0.4 mol/L NaOH was almost five times that of the parent ZSM-5. Treatment with a higher alkaline concentration (0.5 mol/L) greatly reduced the number of Bronsted acid sites and the number of micropores resulting in incomplete methanol conversion. When the alkaline-treated catalysts were washed with acid, some of the porosity was restored and a slight increase in selectivity for aromatics was obtained.