纳米薄层分子筛的合成与应用

The Synthesis of Nanosheets Zeolite and Its Catalytic Application

纳米薄层分子筛(nanosheets zeolite)由于其独特的准二维结构,具有有序的微孔-介孔特征、适宜的表面酸性和良好的扩散性能,已成为分子筛控制合成及其应用研究中标志性的研究热点之一。该类分子筛在合成中采用不同双头或者多头季铵盐(碱)表面活性剂作结构导向剂,所得的纳米薄层分子筛具有晶面二维生长趋向和可控薄层交错形貌,在吸附、催化应用等多方面展现出独特的应用潜力。本文系统总结了季铵盐类表面活性剂对纳米薄层分子筛合成、物化性质的影响以及此类分子筛催化应用研究方面的最新进展,着重介绍了MFI结构的纳米薄层分子筛对甲醇转化制烃、贝克曼重排、异构化、烯烃环氧化等重要催化反应中的优势。最后对这种结构新颖的纳米薄层分子筛在合成和其他应用领域方面未来的研究方向进行了展望。

Nanosheets zeolite is a brand newtype of pseudo 2-dimensional zeolite,possessing distinctive growth trend in the（ 010） crystal surface and hierarchical micro-mesoporous texture,which has triggered an immense interest in the development of nanosheets and its application. The specific morphology can be obtained and dominantly controlled by using multi-quaternary ammonium surfactants as the structure directing agent. Due to its predominant micro-mesoporous property,optimized surface acidity and lower restriction of the diffusion of macro-molecule with respect to conventional bulk zeolite,nanosheets zeolite has tremendous application potential in adsorption and catalysis fields. This reviewsummarizes the advances in the synthesis and the characterization of ZSM-5 zeolite nanosheets with novel morphology. Furthermore, nanosheets zeolite exhibits premium advantages in many applications. Some different reactions that M FI nanosheets zeolite has been applied to are discussed in detail,including methanol conversion to hydrocarbons and macro-molecules involved reaction,i. e.Beckman rearragement reactions. Additionally,newly developed metal-modified nanosheets zeolite has been applied to isomerization,hydroxylation reaction and the epoxidation of olefins etc. Although nanosheets zeolite possesses a large number of strong points compared with conventional zeolite,there is still a long way to go for M FI nanosheets zeolite in improving the synthesis in a more facile / economical way as well as expanding theapplications. The outlook section cast great expectation on nanosheets for enlightening the innovative design of other materials.