Pure-Supramolecular-Linker Approach to Highly Connected Metal–Organic Frameworks for CO2 Capture

A pure-supramolecular-linker (PSL) approach for the formation of metal–organic frameworks (MOFs) was initially given, which was demonstrated by syntheses of two highly connected and isostructural MOFs, {Fe3O­(TPBTM6–)­(Cl)­(H2O)2}∞ (TPBTM = N,N′,N″-tris­(isophthalyl)-1,3,5-benzenetricarboxamide) (NJU-Bai52, NJU-Bai for Nanjing University Bai group) and {Sc3O­(TPBTM6–)­(OH)­(H2O)2}∞ (NJU-Bai53). Very interestingly, they exhibit exceptional thermal stability, water stability, and highly selective CO2 capture properties. In particular, NJU-Bai53 with higher uptakes (2.74 wt % at 0.4 mbar and 298 K, 7.67 wt % at 298 K and 0.15 bar) and higher selectivity may be an excellent candidate for CO2 capture.

本研究首次提出了用于构建金属有机框架（metal–organic frameworks, MOFs）的纯超分子连接体（pure-supramolecular-linker, PSL）策略，并通过合成两种高连接度且同构的金属有机框架{Fe₃O(TPBTM⁶⁻)(Cl)(H₂O)₂}∞（TPBTM = N,N′,N″-三(间苯二甲酰基)-1,3,5-苯三甲酰胺；NJU-Bai52，其中NJU-Bai指代南京大学白课题组）与{Sc₃O(TPBTM⁶⁻)(OH)(H₂O)₂}∞（NJU-Bai53）对该策略进行了验证。尤为值得关注的是，这两种框架材料展现出优异的热稳定性、水稳定性以及高选择性CO₂捕获性能。其中，NJU-Bai53具备更高的CO₂吸附容量（298 K、0.4 mbar条件下为2.74 wt%，298 K、0.15 bar条件下为7.67 wt%）与更高的选择性，有望成为CO₂捕获的优质候选材料。