新型多孔材料氢气存储和提纯性能改进的多尺度模拟与设计

To exploit safe and high efficient hydrogen storage material at room temperature is one of key issues for utilizing hydrogen energy, and it is an extreme hot topic in current new energy research. Covalent organic frameworks (COFs) and graphene-oxide frameworks (GOFs) are novel porous nanomaterials for potential hydrogen storage. All of them are porous and have large surface areas, which is prerequisite for gas physisorption. Moreover, how to separate the hydrogen from other gases is a critical problem for hydrogen energy application, while two-dimensional COFs, porous graphene, and graphdyine have well-defined pore distribution, which make them possible single-layer membrane for gas separation. This project is facing to the scientific frontier of new energy and novel material fields with government's emphasized support. We plan to schematically investigate the hydrogen storage property by element substituting, light metal doping as well as impregnating with fullerene or nanotube in the bulk structure, and explore the underlying mechanism of improving the hydrogen purification by modifying the pore size of planar structures with various schemes. Also, we will develop the force field from accurate first principles calculations, and with the grand canonical Monte Carlo method, ab initio molecular dynamics, and force-fields based molecular dynamics approaches, we will simulate and design novel nanoscale structures aiming at reaching the most recent DOE 2017 hydrogen storage target at near ambient condition and obtaining high efficient membrane for hydrogen purification. It is hopeful that our study will be beneficial for establishing hydrogen economy and a low carbon world.

寻找安全、高效的室温储氢材料是氢能利用的关键，也是当前新能源领域中倍受关注的热点课题。共轭有机骨架(COF)和氧化石墨烯骨架(GOF)是极具潜力的纳米多孔储氢材料，它们具有优良的多孔性质和大的比表面积，拥有物理吸氢的先天优势。此外，氢气制成后如何与其他杂质气体分离亦是相当重要的问题，二维COF、多孔石墨烯和石墨炔结构拥有规则的孔径分布，可作为气体分离的单层过滤膜。本项目面向国家重点扶持的新能源、新材料等科技前沿，拟系统研究主体材料中元素替代掺杂、轻质金属吸附以及内嵌富勒烯、纳米管等结构的储氢性能，探讨各种修饰方案调节平面结构孔径大小、改善其氢气分离提纯的潜在机理，并利用第一性原理计算发展力场，通过巨正则蒙特卡罗方法、基于从头算分子动力学和基于经典力场的分子动力学，多尺度模拟与设计新型纳米结构，力求达到室温储氢标准，获得高效氢气提纯膜，希望本项目的完成有助于氢经济和地球低碳世界的实现。

本项目利用第一性原理计算、巨正则蒙特卡罗模拟、分子动力学模拟等多尺度理论方法，研究了多种新型二维、三维纳米多孔结构在氢气存储和氢气提纯等方面的应用，探讨分析了元素替代掺杂、金属或化学官能团修饰等方案改善相关气体吸附与分离性能，获得了高效的室温储氢材料和氢气分离膜。此外，本项目从理论上扩展研究了新型纳米材料在光催化及电催化制氢、二氧化碳存储与氧气提纯等更多方面的应用。在本项目的资助下，目前已有十多篇SCI学术论文已正式发表，所获得的研究结果得到了国内外同行的积极评价，本项目为氢能相关材料的实验研究提供了清晰确切的理论依据和指导。