纳米Ga-ZSM-5分子筛的合成及其在苯和稀乙烯烷基化反应中的应用  

Synthesis of nano Ga-ZSM-5 zeolite and its application in alkylation of benzene with dilute ethylene

作　　者：谢卓涵 韩贺 李孝国 张永坤 侯章贵 边凯 张安峰[1] 郭新闻[1] 宋春山[1] XIE Zhuohan;HAN He;LI Xiaoguo;ZHANG Yongkun;HOU Zhanggui;BIAN Kai;ZHANG Anfeng;GUO Xinwen;SONG Chunshan(State Key Laboratory of fine Chemicals,School of Chemical Engineering,Dalian University of Technology,Dalian 116021,China;Research Institute of Refining and Petrochemicals,CNOOC)

机构地区：[1]大连理工大学精细化工国家重点实验室,辽宁大连116021 [2]中海油炼油化工科学研究院

出　　处：《无机盐工业》2022年第2期123-128,共6页Inorganic Chemicals Industry

基　　金：国家自然科学基金青年项目(22008019)。

摘　　要：采用晶种导向法合成了一系列不同硅镓比的纳米级Ga-ZSM-5分子筛,经过挤条成型、酸洗以及高温焙烧等处理后得到了纳米Ga-ZSM-5分子筛催化剂。利用多种表征技术对Ga-ZSM-5分子筛的结构和酸性质进行了表征,研究了其催化苯与稀乙烯烷基化反应性能。结果表明,水热合成的Ga-ZSM-5分子筛具有十字孪晶状形貌,晶粒尺寸均匀。与相同n(Si)/n(T)(T为金属原子)的Al-ZSM-5分子筛相比,Ga-ZSM-5分子筛的酸量和酸强度明显降低。在反应温度为360℃、压力为1.4 MPa、乙烯质量空速(WHSV)为1.5 h^(-1)、n(苯)∶n(乙烯)=1∶1,n(乙烯)∶n(氮气)=1∶5.67的反应条件下,Ga-ZSM-5分子筛催化剂表现出了较高的乙基选择性,副产物二甲苯比Al-ZSM-5减少了30%~50%,且在100 h内稳定运转,具有更好的抗积炭能力。A series of nano Ga-ZSM-5 zeolites with different Si/Ga ratio were synthesized with seed-oriented method.Ga-ZSM-5 catalysts were obtained with extrusion molding,acid pickling and high temperature roasting.The structure and acid properties of Ga-ZSM-5 zeolites were characterized by various techniques and their catalytic performance in the alkylation of benzene with dilute ethylene were evaluated.The results showed that hydrothermal synthesized Ga-ZSM-5 molecular sieves exhibited intergrown morphologies and uniform particle size.Compared with Al-ZSM-5 zeolites with the same n(Si)/n(T)(T was metal atom),the acid content and acid strength of Ga-ZSM-5 zeolites were significantly reduced.Under the reaction conditions of T=360 ℃,P=1.4 MPa,weight hourly space velocity(WHSV) of ethylene=1.5 h^(-1),n(benzene)∶n(ethylene)=1∶1,n(ethylene) ∶n(nitrogen) =1 ∶5.67,Ga-ZSM-5 zeolites catalysts showed higher ethylbenzene selectivity and 30% ~50%reduction for xylene selectivity compared with Al-ZSM-5.In addition,Ga-ZSM-5 zeolites catalyst remained stable during the time on stream of 100 h with stronger coke-resistant capacity.

关 键 词：Ga-ZSM-5 苯与稀乙烯烷基化 乙苯 酸性质 

分 类 号：TQ127.2[化学工程—无机化工]