摘要
ZSM-5,ZSM-11和ZSM-39三种沸石骨架均由五元环组成,它们都是高硅沸石.其中ZSM-5是少数有应用价值的分子筛催化剂之一,主要应用在二甲苯异构化、甲苯歧化和甲醇转化为汽油等催化反应. 通常分子筛合成都是在碱金属或碱土金属离子存在下进行的,必须经过铵离子交换才能转变为氢型分子筛催化剂.其晶体粒度较小并且易于生成杂晶相.
ZSM-5, ZSM-11 and ZSM-39 zeolites have been synthesized from R-SiO2-Al2O3-H2O systems, in which R is tetraethylammoniurn hydroxide, tripropylamine, triethylamine, ethylenediamine, diethanolamine and 1,6-hexanediamine for ZSM-5 and is tetrabutylammonium hydroxide and isopropylamine for ZSM-11 and ZSM-39 respectively. The H-form of the zeolites will be obtained when the precursors are heated to remove the occluded organic ions without ion exchange.The size of the crystal obtained from these systems is larger than that from R-Na2O-SiO2-Al2O3-H2O systems.
基金
国家自然科学基金
