摘要
以ZSM-5分子筛为核相,通过聚二烯丙基二甲基氯化铵(PDDA)偶连纳米Beta分子筛晶种,经动态水热合成方法制备了ZSM-5@Beta核壳二元复合分子筛。采用XRD、N吸附-脱附、SEM、TEM、ICP、NH-TPD及Py-FTIR等手段对复合分子筛的结构和物性进行了表征,考察了复合分子筛催化2-甲萘(2-MN)与甲醇烷基化合成2,6-二甲基萘(2,6-DMN)的催化性能。结果表明,采用该方法制备出粒径约为500 nm的核壳结构ZSM-5@Beta复合分子筛。与机械混合二元分子筛相比,核壳结构材料具有更高的比表面积和外表面积,并降低了酸强度和强酸中心密度。通过限域催化理念、核壳界面和多级孔道的构建,借助12元环壳相Beta分子筛提高催化活性,利用10元环核相ZSM-5的择形催化作用提高催化选择性。在2-MN与甲醇烷基化反应中提高了2-MN的转化率和2,6-DMN的选择性,产物中2,6-/2,7-DMN比达到1.35,2,6-DMN收率达到4.29%。
ZSM-5@Beta core-shell molecular sieve was prepared by dynamic hydrothermal synthesis method using ZSM-5 adhered Beta seed crystals as the core phase, and polydiallyl dimethyl ammonium chloride(PDDA) was used as a coupling agent to adhere Beta seed crystals on the surface of ZSM-5. The structure and physical properties of composite molecular sieves were characterized by XRD, Nadsorption-desorption, SEM, TEM, ICP, NH-TPD and Py-FTIR. The catalytic performance of composite molecular sieves for alkylation of 2-methylnaphthalene(2-MN) with methanol was investigated. The results showed that ZSM-5@Beta composite molecular sieve prepared by this method had a core-shell structure, and the particle size was about 500 nm. Compared with mechanically mixed binary molecular sieve, core-shell molecular sieve had higher specific surface area and external surface area, lower acid strength and stronger acid center density. Through the construction of core-shell interface and hierarchical porous, the catalytic activity was improved by shell phase Beta molecular sieve with 12-membered ring channel, and the catalytic selectivity was improved by core phase ZSM-5 molecular sieve with 10-membered ring channel in the alkylation reaction of 2-MN with methanol. The 2,6-/2,7-DMN ratio in the products reached 1.35, and the yield of2,6-DMN reached 4.29%.
作者
盛路阳
展俊岭
张旭鹏
吴邦昊
张钰
张吉波
SHENG Lu-yang;ZHAN Jun-ling;ZHANG Xu-peng;WU Bang-hao;ZHANG Yu;ZHANG Ji-bo(Jilin Institute of Chemical Technology,School of Petrochemical Engineering,Jilin 132022,China;Jilin University,College of Chemistry,Changchun 130021,China)
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2022年第9期1202-1210,共9页
Journal of Fuel Chemistry and Technology
基金
吉林省科技发展计划(20200401029GX)资助。
