多酸共价连接的多孔有机聚合物的设计合成及催化性能研究

The covalent modification of polyoxometalates (POMs) has enhanced the structural stability as well as the synergistic effect between organic and inorganic components, enabling these materials for many promising applications. Now the major researches are usually limited in isolated molecules or linear polymers by the covalent binding of small organic molecules, while the other structures still remain largely unexplored. In this project, porous organic polymers (POPs) with regular network structures linked by POMs will be designed and synthesized by using the organic-inorganic POMs as the building blocks, which is obtained via the covalent binding of organic ligands to inorganic POM units. Here multiple organic-inorganic POM blocks can be prepared controllably through selecting the different POM units and organic ligands with various covalent bindings. Based on this, a series of POPs containing POM with 2D or 3D structures can be synthesized in a variety of organic reactions, such as schiff-base reaction, coupling reaction and addition reaction. The physicochemical properties of these POPs, such as regular structure, porous nature, material morphology and stability, will be investigated systematically by means of a variety of characterizations, and their applications will be developed in chemocatalysis. This project will not only enrich the studies and develop the applications of POMs and POPs by using POMs as the building blocks for POPs, but also provide a new approach for developing the functional hybrid materials and their applications in catalysis.

多酸的共价修饰可增强结构稳定性及有机-无机组分间的协同性，在诸多领域展现出广阔的应用前景。目前这类材料多为有机小分子修饰的独立分子或链状聚合物，其他结构类型的报道相对较少。本项目拟以多酸为无机构筑单元，通过共价连接有机配体得到有机-无机杂化模块，并以此为基本构筑块制备具有规整网络结构的多酸连接的多孔有机聚合物。通过选取不同结构类型的多酸构筑单元及不同共价连接方式的配体，可控合成不同结构的多酸构筑模块。在此基础上，借助多种有机化学反应(席夫碱反应、偶联反应、加成反应等)与有机配体进一步组装成二维或三维多孔有机聚合物。采用多种表征手段研究所得聚合物的结构规整度、多孔性质、微观形貌及稳定性等基本物理化学性质，并探索其在化学催化领域的应用。本项目将多酸作为多孔有机聚合物的基本构筑单元，极大地丰富了多酸和多孔有机聚合物学科的研究，为拓展功能性杂化材料的种类及其在催化领域的应用发展提供新思路。

独特的酸性及氧化还原性使多酸被用于多种催化反应，但其本身差的孔隙性及高度可溶性限制了其在异相催化中的应用。多孔有机聚合物具有质量轻、比表面积大、稳定性好、结构可调孔、易功能化等特点，是一种极具发展潜力的多孔材料。因此，将多酸单元引入到多孔有机聚合物的中，可集合二者特有的优势，制得更多功能的杂化材料。基于此，本项目将多酸阴离子与带正电性的多孔有机聚合物通过静电作用结合，并将其用于催化二氧化碳的化学转化中。多酸阴离子均一地分布在多孔有机聚合物骨架中，位点明确且彼此分隔，既保证了多酸阴离子与反应物分子的充分接触，又有效地避免了多酸阴离子的聚集及从载体上脱离，实现催化性能的显著提升和催化剂的循环利用。此外，项目还探索了包含金属的有机聚合物衍生的材料在电催化反应中的应用。所得的衍生材料也具有较好的多孔性，同时实现原位的杂原子掺杂，在多种电催化反应中表现出良好的性能。本项目为拓展基于多酸及多孔有机聚合物复合材料的种类以及其在催化领域的应用发展提供新的思路。