CTAB辅助晶种法制备ZSM-5催化MTP反应  

Preparation of ZSM-5 catalysts for MTP reaction by CTAB-assisted seeding method

作　　者：张昊[1] 刘民[1] 郭新闻[1] ZHANG Hao;LIU Min;GUO Xinwen(State Key Laboratory of Fine Chemicals,Frontier Science Center for Smart Materials,School of Chemical Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China)

机构地区：[1]大连理工大学化工学院,精细化工国家重点实验室,智能材料化工前沿科学中心,辽宁大连116024

出　　处：《化工学报》2024年第10期3579-3587,共9页CIESC Journal

基　　金：国家自然科学基金项目(21972013);辽宁省“兴辽英才计划”项目(XLYC2008032)。

摘　　要：在晶种法合成过程中添加不同比例的十六烷基三甲基溴化铵(CTAB)作为晶体生长抑制剂制备了一系列纳米ZSM-5团聚体分子筛样品。采用XRD、SEM、ICP、氩气物理吸附、NH_(3)-TPD等分析手段表征了催化剂的孔结构和酸性等,并阐述了CTAB对ZSM-5分子筛物化性质的影响:适量CTAB的添加在促进ZSM-5分子筛晶化的同时可抑制晶体的进一步生长,使初级纳米晶粒产生团聚,增加了比表面积,促进了微孔孔道的构筑,增加了酸性位点。采用固定床反应器评价了样品在高空速下的甲醇制丙烯(MTP)催化性能。结果显示,样品Z5-2(合成初始物料中CTAB/SiO_(2)摩尔比为0.02)具有适宜的孔结构和酸量,表现出较好的催化性能,丙烯选择性为47.6%。A series of nano-sized ZSM-5 agglomerates were prepared by adding different ratios of cetyltrimethylammonium bromide(CTAB)as a crystal growth inhibitor during the synthesis of crystal seeding method.The pore structure and acid properties of the samples are characterized by XRD,SEM,ICP,Ar adsorption-desorption,NH_(3)-TPD and other analytical methods,and the effects of CTAB on the physical and chemical properties of ZSM-5 molecular sieves were elaborated.The addition of appropriate amount of CTAB inhibited the further growth of crystals while promoting the crystallization of ZSM-5 molecular sieves,so that the primary nano-crystals agglomerated to increase the specific surface area,while promoting the construction of micropores and increasing the acid sites.The catalytic performance of this group of molecular sieve samples was evaluated for the methanol to propylene(MTP)reaction at high air velocity using a fixed-bed reactor.The results showed that sample Z5-2(with a CTAB/SiO_(2) molar ratio of 0.02 in the synthesized initial material)had suitable pore structure and acid volume,and exhibited good catalytic performance with propylene selectivity at 47.6%.

关 键 词：分子筛 晶种 催化剂 甲醇制丙烯 

分 类 号：O643[理学—物理化学]