超薄二维MOF膜的可控组装及甲烷纯化研究

The state-of-the-art technology for the separation of CH4/CO2 uses amine adsorption, which is a complex, labor-intensive and costly approach. Membrane separation technology is far less expensive and requires less energy consumption. Although membrane-based separations have been considered as a promising technology, the performance of current membrane materials should be improved further for industrial applications. Metal organic framework (MOs) membrane with the character of controllable design, defined structure, and excellent performance attracted a great deal of concerns, and also demonstrate high potential for separation of CO2/CH4. Herein, we proposed a new idea that the well-designed and prepared ultrathin membrane, constructed from the single and multiple layered two dimensional (2D) MOFs with functional pore environment, could demonstrate high fast and efficient methane purifications. Detail as follows, ① based on the established strategy of supramolecular building block, the water stable 2D MOFs featuring varied hydrophobic groups and suit pore properties will be designed and prepared; ② by the technique of “solvent assistance” and "spraying substrate", the uniformly separated MOF nano-sheets will be employed to prepare ultrathin molecular sieve membrane; ③ systematical investigation on pore modifications, membrane thickness, approaches of membrane preparation and varied gas proportion will be done for realizing the membrane with excellent performance (simultaneous increased permeance and selectivity) towards the purification of methane systems. Therefore, overall, our work will offer not only the stone for feasible usage of MOFs in industry, but also a scientific support for finding membrane materials with independent creation.

工业上甲烷/二氧化碳分离主要采用氨溶液吸收的策略。然而，该策略不仅给环境带来污染，还需要耗费大量的能量。膜技术被认为是实现高效率分离且低能耗的重要手段之一。面对高性能膜材料的设计，金属有机骨架（MOF）膜以其方便的孔结构设计、优良的分离性能等优点受到极大关注。本项目提出“设计和制备含有功能化孔道环境的超薄二维MOF膜，用于高效率、持久性甲烷/二氧化碳分离”的新思路。具体为：①结合功能化修饰有机配体以及超分子基元策略，控制合成新型二维MOF材料；②运用“溶剂辅助”，“喷涂底基”等策略，实现超薄MOF层片以及大面积超薄膜的制备；③深入探索膜微观孔道极性，孔道尺寸，膜厚度，成膜方法、混合气体比类等对分离性能的影响，以期实现高通量、高选择性、持久性的分离效果。项目的实施不仅有助于推进MOF材料工业化发展的脚步，同时为开发具有自主创新的高性能膜材料提供更多理论依据和技术支持。

甲烷深冷纯化是天然气工业中最耗能的过程，然而基于膜技术的分离被认为是实现低能耗的重要手段之一。金属有机骨架材料以其方便的孔结构设计、优良的存储和分离性能等优点受到极大关注。本项目提出“设计和制备含有功能化孔道环境的超薄金属有机骨架膜，用于高效率、持久性甲烷纯化”的新思路。受项目支持，负责人和团队成员按照任务书有序开展气体分离导向MOF结构设计以及超薄MOF膜组装的研究工作。设计与合成一系列MOF材料新材料，准确测定其物质属性，探索构效关系，优化MOF纳米片剥离方法，针对分离组装组装系列MOF膜，研究气体在膜层中的吸附和扩散行为，运用分子模拟手段研究膜微结构和甲烷选择性分离的关系，指导晶体材料和膜结构的再设计，实现MOF膜在甲烷纯化的连续化分离构想。构建的MOF膜对甲烷/二氧化碳组分展现优异性能，其CO2通量高达1200 Barrer，其选择性长期稳定在40，性能岁温度有变化，但具有可逆特点。构建的MOF吸附剂，展现出当时最高的甲烷纯化能力（1.17g甲烷/1g MOF）。建立一套从MOF设计到MOF膜应用的技术参数。在J. Am. Chem. Soc., Angew. Chem. Int. Ed., J. Membr, Sci., ACS Appi. Mater. Inter.等杂志发表第一作者/通讯作者SCI论文38篇，申请专利3项，授权1件；在化学化工领域重要会议上作邀请报告10余次；研究工作被相关领域国际知名课题组在Science, Nat. Chem.等杂志上评述并引用。候选人江苏省“青蓝工程”中青年学术带头人，江苏省“六大”人才高峰计划；作为骨干，入选首批教育部 “全国高校黄大年式教学团队”（材料化学工程团队），张家港奖教金等荣誉称号。