PP_(1,4)Br/PP_(1,8)Br离子液体模板剂制备ZSM-11及其催化性能评价  

Preparation of ZSM-11 by PP_(1,4)Br/PP_(1,8)Br ionic liquid template and its catalytic performance evaluation

作　　者：谷乐 娄鑫玉 张金颐 孟祥太[1] 张舜光 GU Yue;LOU Xin-yu;ZHANG Jin-yi;MENG Xiang-tai;ZHANG Shun-guang(School of Chemistry and Chemical Engineering,Tianjin University of Technology,Tianjin 300384,China)

机构地区：[1]天津理工大学化学化工学院,天津300384

出　　处：《高校化学工程学报》2021年第3期483-491,共9页Journal of Chemical Engineering of Chinese Universities

基　　金：天津市教委科研计划项目(2018KJ138)。

摘　　要：针对多级孔分子筛制备工艺复杂、易产生相分离等问题,提出采用离子液体多功能模板剂制备ZSM-11分子筛。以溴化N-丁基-N-甲基哌啶(PP_(1,4)Br)和溴化N-辛基-N-甲基哌啶(PP_(1,8)Br)离子液体为复合模板剂,硅溶胶为硅源,偏铝酸钠为铝源,采用温和水热合成方法,制得ZSM-11分子筛。在模板剂总量不变时,考察了PP_(1,4)Br与PP_(1,8)Br的物质的量比n(PP_(1,4)Br):n(PP_(1,8)Br)在1:6~6:1变化时,制得ZSM-11分子筛的结构、酸性及催化性能。结果表明,不同n(PP_(1,4)Br):n(PP_(1,8)Br)下制得的ZSM-11分子筛,其结构和酸性都有所不同,进一步影响了其在苯甲醇烷基化反应中的催化性能,当n(PP_(1,4)Br):n(PP_(1,8)Br)=5:2时,ZSM-11分子筛催化剂具有丰富的微孔、介孔和适宜的酸性,其催化性能较优,与现有工艺相比,在二甲苯选择性同为35%时,其苯的转化率可达68.16%,比现有报道高出近10%。Ionic liquid multi-functional template was used to prepare ZSM-11 molecular sieves because of complex and easy phase separation in preparation process of multistage porous molecular sieves.ZSM-11 molecular sieves were synthesized by mild hydrothermal method using N-butyl-N-methyl piperidine bromide(PP_(1,4)Br)and N-octyl-N-methyl piperidine bromide(PP_(1,8)Br)as composite templates,silica sol as silicon source and sodium aluminate as aluminum source.The structure,acidity and catalytic performance of ZSM-11 zeolites were investigated when n(PP_(1,4)Br)/n(PP_(1,8)Br)was 1:6 to 6:1 with the same amount of template agent.The results show that ZSM-11 zeolites prepared at different n(PP_(1,4)Br)/n(PP_(1,8)Br)have different structures and acidity,which further affect their catalytic performance in the alkylation of benzyl alcohol.ZSM-11 zeolite catalyst prepared at n(PP_(1,4)Br):n(PP_(1,8)Br)=5:2 has rich micropores,mesopores,suitable acidity and better catalytic performance.Compared with the traditional process,the conversion of benzene could reach 68.16%when the selectivity of xylene was 35%,which was nearly 10%higher than that reported.

关 键 词：ZSM-11 离子液体 水热合成 烷基化 催化剂 

分 类 号：O643.3[理学—物理化学]