氢气分离功能导向的新型多孔膜的设计合成与制备

Since H2 is a great potential candidate of “clean” and efficient energy and important raw material in chemical industry, the separation and purification processes of H2 is an important issue in H2 production and practical applications. Membrane separation is considered to be the most promising H2 separation technology because of low energy consumption, dramatically lower investment cost, high efficiency etc. However, current H2 separation membranes are generally with low H2 permeability or low H2 selectivity and other weaknesses. Metal-organic frameworks (MOFs) and porous aromatic frameworks (PAFs) are two kinds of new microporous materials, with high surface area, abundant structures, and tunable pore functionalities. Hence, MOFs and PAFs serve as an ideal platform for the development of next generation of membrane materials for gas separation owing to their large capacity and selectively adsorption for gases. Based on our previous study on MOF and PAFs, in this project, we will explore and study the membranes with high stability, high permeability and high selectivity for H2 separation as followings: (1) synthesizing large-scale continuous MOF membranes supported on porous ceramic, porous metal oxide, porous glass and hollow polymer fibers, screening novel MOF membrane for H2 separation applications; (2) fabricating mixed matrix membranes and hollow polymer fibers filled with MOFs or PAFs, developing new mixed matrix membranes for H2 separation; (3) explore new strategies to prepare microporous PAF membranes for H2 separation. Meanwhile, we will study the H2 separation properties of membranes and analyze the H2 separation mechanism based on the research results with the help of theoretical simulations. Through the implementation of this project, it is expected to obtain H2 separation membranes with potentially industrialized and to provide the theoretical and experimental information for the fabrication of next generation of gas separation membranes.

氢气是重要的化工原料和重要的清洁新能源，其分离技术是其生产过程中的关键环节。膜分离技术具有投资少、集成度高、能耗低等优点，但目前氢气分离膜仍存在一些问题如金属膜低渗透率和多孔膜低选择性等。金属有机框架(MOF)和多孔芳香骨架(PAF)是两类新型的微孔材料，具有多样有序可调的微孔结构，将成为制备氢气分离膜的理想材料。本项目在我们前期对MOF和PAF材料的研究基础上，拟从以下几方面开发高稳定性、高透量、高选择性的氢气分离膜：（1）以多孔陶瓷、金属氧化物以及中空纤维等为基底，制备大面积MOF膜，筛选适合氢气分离应用的膜；（2）选用具有储氢功能的MOF和PAF制备聚合物复合基质膜和复合中空纤维等，开发高通量的新型氢气分离复合膜；（3）制备新型具有高效氢气分离能力的微孔PAF膜。同时，利用计算模拟结合实验结果，筛选具有应用价值的新型膜材料。期望通过本项目的实施，为开发新型膜材料提供实验和理论基础。

氢气是重要化工原料和清洁新能源，工业产氢常伴随杂质气的产生，分离是生产过程中的关键环节。膜分离技术具有投资少、集成度高、能耗低等优点，但目前氢气分离膜仍存在低渗透性和低选择性的问题。金属有机框架（MOF）和多孔芳香骨架（PAF）是两类新型有序微孔材料，是制备氢气分离膜的理想材料。本项目围绕开发高稳定性、高渗透率、高选择性的氢气分离膜进行展开，研究内容为：（1）在多孔载体上制备大面积MOF膜，筛选适合氢气分离应用的膜材料；（2）选用储氢功能的MOF和PAF制备复合基质膜和中空纤维膜，开发高通量氢气分离复合膜；（3）制备新型微孔PAF膜，结合计算模拟与分离实验，筛选高效氢气分离能力的膜材料。在多孔膜的设计合成与氢气分离应用方面取得了较好研究成果，研究进展为：（1）设计合成了近20种结构新颖、比表面积大、孔道结构可调、稳定性高的PAF（PAF-61至PAF-110）和MOF材料（JUC系列）。提出了拓扑导向构筑策略定向合成PAF与MOF，具有广泛普适性。（2）开发了快速成核、竞争配位方法，制备了MOF纳米材料。发展了原位法、二次生长法、对扩散法制备了一系列大面积连续MOF膜。氢气通量达到10-6 mol m-2 s-1 Pa-1数量级，选择性接近10。（3）发展了膜材料制备新方法，包括二维剥层、界面法、电化学、丝网印刷等，合成了纳米厚度膜，大幅提升了氢气分离效果。（4）开发了近十种微孔材料（iPAF及CAU等）为分散质，制备了高选择性与高氢气渗透率的复合膜。氢气对氮气分离比超过30，氢气渗透率超过7000 Barrer，远超工业技术标准值。相关研究成果发表在高水平学术期刊上（SCI论文70余篇），应邀撰写多孔膜分离相关综述4篇，出版微孔膜材料英文专著1部，获吉林省科学技术奖一等奖1项，培养研究生30多名。项目的实施推动了功能多孔材料的合成化学的发展，为膜分离科学提供实验和理论基础。