软模板法制备多级孔ZSM-5分子筛的研究进展

相比传统ZSM-5分子筛,多级孔ZSM-5分子筛具有空间位阻小、传质效率高、焦炭少等特点,近年来在分子筛领域应用广泛。多级孔分子筛通常可用后处理法和模板剂法制备,相比后处理法,模板剂法能更好地控制介孔的结构和孔道尺寸。概述了采用传统表面活性剂、两亲性的有机硅烷、双功能多季铵盐表面活性剂及高分子聚合物等软模板法合成多级孔ZSM-5分子筛的研究进展。分析不同软模板剂的特点和作用机理,阐述了合成后分子筛的结构特点及催化性能等。指出在今后的研究中,可以设计价格较低的新型功能化模板剂,优化合成过程,致力于在理解合成机理的前提下,寻找操作简单、绿色环保的合成路线,并将其推行到实际工业生产中。

Research advance in synthesis hierarchical ZSM-5 zeolites with soft templates

Compared with the traditional ZSM-5 zeolite,hierarchical ZSM-5 zeolites has the characteristics of small steric hindrance,high mass transfer efficiency and less coke,and has been widely used in molecular sieve field in recent years.Generally,hierarchical porous zeolites can be synthesized by “top-down” and “bottom-up”.Compared with “top-down”,the “bottom-up” can better control the structure and pore size of mesopores.The method of synthesizing hierarchical ZSM-5 zeolites by soft template method was summarized,including traditional surfactant,amphiphilic organosilane,bifunctional multi-quaternary ammonium salt surfactant and high molecular polymer.The characteristics and mechanism of different soft templating agents were analyzed.The structure and catalytic performance of the synthesized zeolites were introduced.It was pointed out that in the future research,new functional template agents with lower price could be designed to optimize the synthesis process.Under the premise of understanding the synthesis mechanism,researchers could find a simple and environmentally friendly synthesis route and push it into actual industrial production.