原位DRIFTS研究分子筛Bronsted酸和Lewis酸催化戊烯转化的作用机理  

Mechanisms of Bronsted and Lewis acids of zeolite on pentenes conversion by in situ DRIFTS

作　　者：伊凤娇 陈会民 杨勇 曹景沛[1] YI Feng-jiao;CHEN Hui-min;YANG Yong;CAO Jing-pei(Jiangsu Province Engineering Research Center of Fine Utilization of Carbon Resources,China University of Mining&Technology,Xuzhou 221116,China;Chemistry and Chemical Engineering Guangdong Laboratory,Shantou 515031,China;National Energy Center for Coal to Liquids,Synfuels China Co.Ltd,Beijing 101407,China)

机构地区：[1]中国矿业大学江苏省碳资源精细化利用工程研究中心,江苏徐州221116 [2]化学与精细化工广东省实验室,广东汕头515031 [3]中科合成油技术股份有限公司国家能源煤基液体燃料研发中心,北京101407

出　　处：《燃料化学学报（中英文）》2023年第5期625-634,共10页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(22208370);中国博士后科学基金(2021M703500);江苏省“卓博计划”(2022ZB514)资助。

摘　　要：本研究基于原位水热合成和气相浸渍的方法分别合成了含有Bronsted/Lewis酸的Beta分子筛和只含有Lewis酸的AlCl_(3)@Si-Beta样品,并通过原位漫反射红外技术对比研究了Bronsted酸和Lewis酸催化直链和侧链戊烯同分异构体转化作用机理的差异。结果表明,同时含有Bronsted/Lewis酸的Beta分子筛中,Bronsted酸起主要的活化作用,催化戊烯进行异构和叠合反应时均遵循经典的碳正离子机理;而AlCl3@Si-Beta中的Lewis酸不含氢质子或羟基,催化α-戊烯进行双键迁移和2-戊烯的顺反异构反应时遵循AB-AD机理,以类烯丙基物种作为中间体,无法催化戊烯进行骨架异构和叠合反应。Zeolites have been extensively used in the chemical and petrochemical industries owing to their tunable acidities and unique pore structures.Beta zeolite with Bronsted and Lewis acids and AlCl_(3)@Si-Beta with only Lewis acid were prepared by hydrothermal synthesis and gas-phase impregnation methods,respectively.Mechanisms differences of Bronsted and Lewis acids on four pentene isomers transformation were investigated by in situ diffraction infrared Fourier transform spectrum(DRIFTS).The results suggested that Bronsted in Beta played a main role in isomerization and oligomerization reactions which all followed classical carbenium ion mechanisms.On the contrary,Lewis acid in AlCl_(3)@Si-Beta without hydrogen proton or hydroxyl catalyzed α-pentene doublebond migration to produce β-pentene and cis-trans isomerization reaction of 2-pentene by AB-AD mechanism with allyl-like species as intermediates,and could not catalyze pentenes skeletal isomerization and oligomerization reactions.

关 键 词：分子筛 Bronsted酸 LEWIS酸 戊烯 作用机理 

分 类 号：O643.38[理学—物理化学]