微孔材料理论模拟的进展与展望

Progress and Prospect of Theoretical Simulation of Microporous Materials

微孔材料是指孔径小于2 nm的多孔材料,被广泛应用于非均相催化、吸附、分离、储气等先进工艺中.按照组成结构分类,由于这些材料在元素组成及结构特征上的多样性,因此原则上能够合成的此类材料数目巨大.仅通过实验手段无法有效地对这些具有潜在应用价值的材料进行研究.随着计算机资源与数值计算方法的迅速发展,理论计算方法研究微孔材料不仅可以提供分子水平上对材料特性的认知,而且可以从微观尺度上揭示实验机理,有利于建立结构与性能的对应关系,从而推动新型微孔材料的设计与开发.综述了近年来针对各种类型微孔材料的理论研究方法及最新的理论研究成果.指出了理论方法在微孔材料研究进程中存在的主要问题、发展前景及今后的研究方向.

Microporous materials, which refers to the porous materials with pores of less than 2 nm, have been widely used for heterogeneous catalysis, adsorption, separation, gas storage and other numbers of advanced applications. Their high-profile application is mainly focused in the field of energy and environment research, such as the storage and separation of hydrogen, carbon dioxide and methane. According to the compositions and structures, common microporous materials include molecular sieves, porous carbon materials, metal-organic framework compounds(MOF) and microporous organic polymer(MOP). Due to the diversity of element components and structure characteristics, the number of the microporous materials, which can be synthesized in principle, is considerably large. It is impossible to study these materials only by means of experimental methods. With the rapid development of computing power and numerical methods, the theoretical methods used in the studies of microporous materials not only provide the material properties at the molecular level, but also reveal the micro-scale experimental mechanism. Therefore, it is beneficial for establishing the corresponding relationship between the material structures and their properties, leading to promoting the design and development of novel microporous materials. Currently, the accurate theoretical simulations firstly calculate the intermolecular interactions between the key moiety originated from the microporous material and the target molecule through the computational method of quantum chemistry, thereby acquired the potential energy curve of the system. Then the van der Waals interaction parameters of the force field were fitted. Based on the force field, the processes of gas adsorption in the porous materials were simulated by Grand-Canonical Monte-Carlo(GCMC) method. Good agreements between GCMC simulation results and experimental data for adsorption isotherms and heats of adsorption have been observed in many studies. This paper reviews the theoretical methods recently used in the study of the various microporous materials and the latest theoretical research findings. Moreover, the main problems, development prospects and the direction for future research in the study of microporous materials are pointed out.