乙基环己烷在择形分子筛上的异构化反应

摘要

通过乙基环己烷(ECH)在ZSM-5,MOR,EU-1分子筛上的反应,考察三种分子筛上的催化反应性能.采用X射线衍射(XRD)、N2-吸附(BET)、NH3-TPD、Py-IR吸附及热重方法表征分子筛的结构和酸性.结果表明:在ECH反应的复杂网络中,分子筛的孔道结构会对反应产物分布有重要影响；ECH异构化反应需要大量中强酸中心和较大的反应空间,具有十二元环孔道的MOR分子筛和具有十二元环侧笼的EU-1分子筛有较好的异构化反应性能.综合比较,三种分子筛中,EU-1分子筛上的ECH转化率和C8异构选择性较高.%The isomerization of ethylcyclohexane (ECH) was investigated via three types of shape selective molecular sieve, ZSM-5, MOR and EU-1. The structural and acidic properties of these molecular sieves were characterized by XRD,N2 adsorption,NH3-TPD, Py-IR adsorption and TG techniques. The experimental results demonstrate that the structure and acidity of various molecular sieves play an important role on the reaction network of ECH isomerization, especially the pore structure. In ECH isomerization reactions, more strong/medium acid sites and enough space for reaction are required. Since MOR has 12-membered ring structure and EU-1 has 12-membered ring side pockets, they possess better reaction activity. On the whole, among these three molecular sieves, EU-1 exhibits as the optimal catalyst for ethylbenzene isomerization based on its high ECH conversation and good C8 isomerization selectivity.