摘要
本研究采用水热结晶法合成了孪晶HZSM-5分子筛,并在表面外延生长Silicalite-1(S-1)纯硅沸石,制备了HZSM-5@Silicalite-1核壳结构催化剂。与孪晶HZSM-5相比,HZSM-5@Silicalite-1核壳结构催化剂在甲苯甲醇烷基化反应中表现出优异的催化性能。在470℃、0.1 MPa和临氢反应条件下,HZSM-5@40Silicalite-1催化剂的甲苯单程转化率为8.5%,对二甲苯选择性为98.4%。进一步研究了核相HZSM-5与S-1壳层前驱体固液质量比对表面S-1晶体生长的影响,同时考察了S-1壳层对孪晶HZSM-5催化性能的影响。通过SEM、XRD、XRF、液体静态吸附、N_(2)吸附-脱附、NH_(3)-TPD、Py-FTIR等表征实验对核壳材料的结构和酸性质进行了详细研究。
The technology of alkylation of toluene with methanol to p-xylene has attracted much attention due to the high selectivity of p-xylene and low energy consumption in product separation unit.Twin HZSM-5 molecular sieve has the characteristics of large coverage proportion of zigzag channels on the surface and less aluminum distribution on the outer surface.It shows high selectivity for p-xylene in the alkylation of toluene and methanol.In this paper,silicalite-1(S-1)was grown epitaxially on the surface of twin HZSM-5 molecular sieve by hydrothermal crystallization,and twin HZSM-5@Silicalite-1 core-shell catalyst was obtained.Compared with twin HZSM-5,HZSM-5@40Silicalite-1 core-shell catalyst shows excellent catalytic performance in toluene methanol alkylation.Under the reaction conditions of 470℃,0.1 MPa and hydrogen atmosphere,the conversion of toluene is 8.5%and the selectivity of p-xylene is 98.4%.Then,the effect of solid-liquid mass ratio of nuclear HZSM-5 and silicalite-1 shell precursors on the growth of silicalite-1 crystal was further studied,and the effect of silicalite-1 on the catalytic performance of twin HZSM-5 was investigated.The pore structure and acid properties of core-shell materials were studied in detail by SEM,XRD,XRF,liquid static adsorption,N_(2) adsorption desorption,NH_(3)-TPD and Py-FTIR.
作者
潘旭
杜冰
黄鑫
王瑞壮
韦慧
张海永
刘意
许德平
PAN Xu;DU Bing;HUANG Xin;WANG Rui-zhuang;WEI Hui;ZHANG Hai-yong;LIU Yi;XU De-ping(China University of Mining and Technology-Beijing,School of Chemical&Environmental Engineering,Beijing 100083,China;National Institute of Clear-and-Low-Carbon Energy,Beijing 102209,China)
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2022年第5期611-620,共10页
Journal of Fuel Chemistry and Technology
