H-Beta酸改性对甲苯叔丁基化性能的影响  

Influence of H-Beta Acid Modification on the tert-Butylation of Toluene

作　　者：王园园[1] 宋华[1] 王雪芹[1] 张梅[1] 王文艺[1] 朱天汉 WANG Yuanyuan;SONG Hua;WANG Xueqin;ZHANG Mei;WANG Wenyi;ZHU Tianhan(College of Chemistry & Chemical Engineering, Northeast Petroleum University, Daqing 163318, China)

机构地区：[1]东北石油大学化学化工学院,黑龙江大庆163318

出　　处：《石油学报（石油加工）》2022年第2期302-311,共10页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：黑龙江省杰出青年基金项目(JC2018002);黑龙江省青年基金项目(QC2017005);东北石油大学青年基金项目(2018QNL-26);东北石油大学人才引进科研启动费资助项目(1305021821)资助。

摘　　要：分别采用无机酸(磷酸、硝酸、盐酸)和有机酸(乙酸、酒石酸、柠檬酸)对H-beta分子筛进行酸处理改性,并将其用于催化甲苯叔丁基化反应。采用XRD、XRF、SEM、TEM、FT-IR、NH_(3)-TPD、Py-IR等手段对酸改性H-beta分子筛进行表征。结果表明:无机酸对分子筛的骨架铝溶解作用较强,总酸量下降,催化活性降低;有机酸和铝物种之间存在较强的络合作用,可有效调控分子筛的酸性位,增加对烷基化有利的中强酸和B酸含量,H-beta分子筛的催化活性有所增强。其中,柠檬酸改性后的H-beta分子筛(CA/H-beta)在烷基化反应过程中表现出最好的催化活性。在180℃、n(叔丁醇)/n(甲苯)为3、CA/H-beta分子筛1.0 g、溶剂(环己烷)60 mL的条件下反应4 h,甲苯转化率可达67.1%,对叔丁基甲苯(4-TBT)选择性高达80.5%。HCA/H-beta分子筛重复使用5次,依然表现出较好的催化活性。H-beta zeolites were acid modified separately with inorganic acids(phosphoric acid,nitric acid and hydrochloric acid)and organic acids(acetic acid,tartaric acid and citric acid),and later used for catalyzing tert-butylation of toluene.The acid-modified H-beta zeolites were characterized by means of XRD,XRF,SEM,TEM,FT-IR,NH_(3)-TPD and Py-IR,etc.The results show that inorganic acids can easily dissolve the framework aluminum of zeolites,which reduces the total acid content and catalytic activity.There is a strong complexation between organic acids and aluminum species,which can effectively regulate the acid sites of zeolites,increase the content of intermediate-strong acids and B acid that are good for alkylation,and enhance the catalytic activity of H-beta zeolite to some extent.Specifically,the H-beta zeolite modified with citric acid(CA/H-beta)shows the best catalytic performance in the alkylation reaction process.When the temperature is 180℃,the n(tert-butyl alcohol)/n(toluene)is 3,the amount of CA/H-beta zeolite is 1.0 g,the volume of cyclohexane is 60 mL and the reaction time is 4 h,the conversion rate of toluene can reach 67.1%and the selectivity of tert-butyl toluene(4-TBT)can reach up to 80.5%.Moreover,HCA/H-beta zeolite can also present a stable catalytic performance after reused for 5 times.

关 键 词：分子筛 烷基化 有机酸 无机酸 改性 

分 类 号：O643[理学—物理化学]