增强MOFs水汽稳定性的SBU修饰策略及其同时稳定材料结构和性能的机理

针对MOFs材料普遍存在水汽不稳定性制约其应用的瓶颈问题，本项目提出研究增强MOFs水汽稳定性的SBU修饰策略及其同时稳定材料结构和性能的机理。拟通过对MOFs次级结构单元（SBU）的修饰，抑制水分子的进攻，在水汽工况下同时增强材料结构和吸附性能的稳定性，并得到一系列高容量、高水汽稳定性、高选择性的MOFs吸附材料，这是项目特色和创新之处。研究内容涉及：在理论层面，揭示MOFs的SBU化学微环境对其水汽稳定性、孔隙结构和表面化学的影响规律；在材料制备层面，研究纳米晶种法、后合成修饰法进行SBU修饰的新技术；在分离科学层面，围绕我国当前天然气和生物甲烷生产需求，研究CO2/CH4/H2O在材料上的吸附热力学、动力学、选择性，以及其竞争吸附机理和多组分分离过程。项目将为MOFs结构和性能水汽稳定性的同时增强提供新的理论和技术，并为高效分离纯化生物甲烷和天然气的工业应用提供新的科学基础。

Metal-Organic Frameworks (MOFs) are a class of promising adsorbents with high capacity and superior selectivity. However, the stability of most MOFs cannot withstand humidity, which hinders their potential applications. In this project, we have proposed a novel strategy that functionalizes the secondary building unit (SBU) of MOFs, so as to simultaneously enhance their structural stability and adsorptive capacity against moisture. In this way, a series of novel MOFs with high capacity, enhanced steam stability, and superior CO2/CH4 selectivity were developed for biomethane and natural gas upgrade applications. This project will be carried out from the following 3 aspects: (1) From the aspect of mechanism study, the influence of SBU micro-environment on the steam stability, porous structure, and surface chemistry of MOFs will be interpreted. (2) From the aspect of materials fabrication, efficient technologies such as nano-seed assisted ultrafast synthesis and post-synthetic modification will be adopted and optimized, and the relationship between the synthetic conditions and materials’ properties will also be concluded. (3) From the aspect of separation science, the steam stability of the MOFs synthesized in this work will be tested under the moist working conditions, their CO2/CH4/H2O adsorptive equilibrium will be studied, and their competitive adsorptive separation process will be comprehensively investigated. The outcomes of this project will facilitate the applications of biomethane production and natural gas upgrade with novel theoretic and technical foundations, and thus have significance in materials science as well as industrial applications.