基于多级孔沸石催化剂的芳烃苄基化研究

Benzylation Reaction of Aromatic Hydrocarbon over Hierarchical Zeolitic Catalysts

多级孔沸石是一类同时包含有相互交联的微孔和中孔的沸石催化材料,其固有的酸性为其提供活性位,而发达的中孔体系有助于酸性位的接近和分子在其内的扩散,从而有助于催化反应特别是涉及大分子反应的进行。芳烃苄基化反应是一类典型的涉及大分子反应的酸催化反应,寻求合适的固体酸催化剂始终是研究的热点。就近年来多级孔沸石催化剂在各类芳烃分子苄基化反应中的催化性能进行综述和分析,探讨了各类多级孔沸石催化剂,包括ZSM-5,Beta,FAU和丝光沸石中二次中孔的存在对催化剂酸性位的可接近性和分子扩散的促进作用,以及作为芳烃苄基化催化反应催化剂的可能性。研究结果为芳烃苄基化反应提供了一类高效的绿色催化剂,同时为多级孔沸石催化剂的应用提供了一条新路径。

Hierarchical zeolites are a class of superior catalysts which contain simultaneously interconnected mesopores and micropores.The zeolitic micropores bear the catalytic function,while the well-developed mesopores ensure accessibility of acid sites for larger molecules and intracrystalline diffusion.Liquid-phase benzylation of aromatic hydrocarbon is a typical acid-catalytic reaction dealing with bulky molecule,and the development of reusable solid acid catalysts having high activity for the reaction is,therefore,of great practical importance.In this article,the catalytic applications of zeolites with hierarchical pore architecture,involving ZSM-5,Beta,FAU and Mordernite,in benzylation of aromatic hydrocarbon are reviewed with emphasis on the promotion of secondary mesopores to the accessibility of acid sites,mass transport and corresponding catalytic conversion.The results show the feasibility of hierarchical zeolites as catalysts for benzylation of aromatic hydrocarbon and the direction for the application of hierarchical zeolites.