多级孔分子筛的可控构筑与功能化研究

Pursue to organize hierarchical porous structures to deliver desired functionalities has driven considerable efforts worldwide. In the current research proposal, we attempt to establish a simple and versatile approach to organize zeolites into hierarchical porous architectures to achieve improved functinality. Crystalline microporous zeolites are of great commerical significance, however, their microporosity and large internal surface area inhibit their full utilization due to diffusion limitation restricting molecular traffic. Integrating hierarchical porsosity (micro-meso-macro) with the functinality of microporous zeolites will generate brand new hierarchical porous materials that may offer new solutions to the problems facing today's catalysis industry. We use selected species of crystalline microporous zeolites as objects for study. Polysaccharides carry tailorable functionalities and their aerogels exhibit hierarchical porosity which enable them to organize a variety of inorganic compositions into hierarchical porous architectures. The areogels of polysaccharides and their derivatives are employed as reactive structural scaffolds to organize zeolitic nanoparticles into hierarchical porous architectures with controlled pore sizes and interconnectivity. The hierarchical porous architectures of zeolites will be further functionalized through pyrolysis, chemical modifications and hosting of guest species to deliver advanced functinalities.

探索多级孔结构与功能关系，建立可控构筑多级孔功能体系的可持续路线已引起国内外科学界广泛关注。沸石分子筛是具有重要工业价值的催化和吸附分离材料，但是，沸石分子筛的空腔与孔道尺寸限制大分子反应与扩散、也影响新应用领域的开拓。融合沸石分子筛的优异性能与连通多级孔的形状选择性、孔容及传质优势，开发特定多级孔结构的分子筛基材料将为创新传统能源催化功能体系带来新思路。利用多糖化学和结构的可塑性及自组装特性，设计多糖结构基元，利用化学合成、化学组装、化学修饰与主客体组装等手段，深层认识多级孔结构的构筑规律，建立可控构筑特定多级孔分子筛的新路线，为实现多级孔分子筛功能材料的可控构筑与开拓多级孔分子筛新功能体系提供科学依据。

沸石分子筛作为具有规则微孔的晶体材料，被广泛地应用于催化、吸附、分离领域，具有重要的工业价值。但是沸石分子筛微小的孔道尺寸限制了大分子的扩散，也影响了分子筛在新兴领域的应用潜能。因此，多级孔分子筛的结构设计与构筑是现代分子筛材料广受关注的研究领域。近年来，多种制备多级孔分子筛的方法被开发出来，然而其应用只能局限于某一种类型的分子筛，且无法实现对孔结构的调控。本项目中，以生物大分子多糖自组装体为模板，利用其对无机质的诱导矿化的特性，建立了一种具有普适性的构筑多级孔分子筛的新路线，并以此成功构筑了多种类型的分子筛。总结多糖的自组装规律，调变多糖框架模板的结构，进而实现了对多级孔分子筛孔结构的调控，并进一步探究了多级孔分子筛孔道结构特征与其性质之间的关系。实现多级孔分子筛的孔结构调节，有利于开拓了多级孔分子筛的应用潜能。