Y/ZSM-5核-壳复合分子筛的合成及其催化性能研究  

Synthesis and catalytic performance of Y/ZSM-5 core-shell composite molecular sieves

作　　者：董哲 刘继东[1] 吕建华[1] 王荷芳[1] DONG Zhe;LIU Ji-dong;Lü Jian-hua;WANG He-fang(School of Chemical Engineering,Hebei University of Technology,Tianjin 300130,China)

机构地区：[1]河北工业大学化工学院,天津300130

出　　处：《应用化工》2020年第2期331-335,340,共6页Applied Chemical Industry

基　　金：国家自然科学基金(21776058);河北省自然科学基金(B2017202226,E2015202262)。

摘　　要：以Y型分子筛在NaOH溶液中溶解产生的Si和Al为硅/铝源,并向其中加入四乙基溴化铵和胶态二氧化硅,经过水热晶化合成Y/ZSM-5核-壳型复合分子筛。通过XRD、SEM、NH3-TPD等表征分别对Y/ZSM-5复合分子筛的结构、形貌和酸性进行了研究;考察了Y/ZSM-5复合分子筛的酸性和孔结构在乙苯加氢脱烷基反应中的催化特性。结果表明,Y/ZSM-5复合分子筛的总酸量低于Y+ZSM-5机械混合样品,复合分子筛的B/L比例高于Y+ZSM-5,证明Y/ZSM-5复合分子筛不是单纯的Y型分子筛和ZSM-5的机械混合,其弱酸量的增加和其独特的孔结构产生的协同作用有利于提升乙苯脱烷基反应的转化率并优化产物分布。Si and Al produced by dissolving Y-type molecular sieve in NaOH solution are silicon/aluminum source.Y/ZSM-5 core-shell composite molecular sieve was synthesized by hydrothermal crystallization with tetraethylammonium bromide and colloidal silica added to the solution.The structure,morphology and acidity of Y/ZSM-5 composite zeolite were studied by XRD,SEM and NH3-TPD characterization.The catalytic properties of the acid and pore structure of Y/ZSM-5 composite molecular sieve in the hydrodealkylation of ethylbenzene were investigated.The results showed that the total acid amount of Y/ZSM-5 composite molecular sieve is lower than that of Y+ZSM-5 mechanical mixed sample,and the B/L ratio of composite molecular sieve is better than Y+ZSM-5.This proved that the Y/ZSM-5 composite molecular sieve is not a pure Y-type molecular sieve and mechanical mixing of ZSM-5.The synergistic effect of the increase of its weak acid content and its unique pore structure is conducive to improving the conversion of ethylbenzene dealkylation reaction and optimizing the product distribution.

关 键 词：复合分子筛 核-壳结构 Y/ZSM-5 加氢脱烷基 

分 类 号：TQ032[化学工程]