高硅LTA型分子筛的合成及应用研究进展

Advances in Synthesis and Application of High-Silica LTA Zeolite

LTA(Linde type A)结构类型的分子筛是早期通过人工合成得到的沸石分子筛之一。目前,工业化的LTA型分子筛即A型分子筛的硅铝比较低,尽管它在吸附和分离等过程中被大量应用,但较差的酸催化活性和水热稳定性限制了其进一步的应用。高硅LTA型分子筛具有比低硅的A型分子筛更好的热/水热稳定性,且在吸附分离以及催化等领域具有独特的应用潜力。本文综述并讨论了自1966年以来高硅LTA型分子筛的合成体系,重点集中在近70年来的发展,包括无机体系和有机体系,针对不同的合成体系以及硅铝比,阐述了其合成机理并对合成方法的优缺点进行了评价。讨论了高硅LTA型分子筛在吸附分离以及催化领域的应用与研究进展,对未来LTA型分子筛的发展与应用进行了展望,并指出深入掌握晶化机理,开发简单的合成体系,廉价的结构导向剂将是高硅LTA型分子筛研究的重点。

The Linde type A(LTA)zeolite is one of the earliest zeolites synthesized artificially.Currently,industrial LTA zeolite typically exhibits a relatively low Si/Al ratio.While it is widely used in adsorption and separation processes,its limited acid catalytic activity and hydrothermal stability hinder its potential for further applications.High-silica LTA zeolites demonstrate enhanced thermal/hydrothermal stability compared to their low-silica counterparts,exhibiting unique application potential in adsorption,separation and catalysis.This paper presents a review of the synthesis systems of high-silica LTA zeolites since 1966,with a focus on developments in the past two decades including inorganic and organic systems.It describes the synthesis mechanisms and evaluates the advantages and disadvantages of various synthesis methods with respect to the different synthesis systems and the Si/Al ratios.Additionally,the advancement of research and applications of high-silica LTA zeolites in adsorption,separation and catalysis are discussed.The future development and application prospects of LTA zeolite are envisioned,and it is highlighted that further research will focus on understanding the crystallization mechanism,developing simple synthetic systems and cost-effective structuredirecting agents for high-silica LTA zeolites.