Polar Ketone-Functionalized Metal–Organic Framework Showing a High CO2 Adsorption Performance

The incorporation of various functionalities into porous metal–organic frameworks (MOFs) represents an efficacious strategy to improving their gas adsorption properties. In this work, a carbonylated tetracarboxylic acid ligand (5,5′-carbonyldiisophthalic acid) was synthesized, and a ketone-functionalized MOF with exposed metal sites based on this ligand was formed successfully. Structural analysis reveals that the new MOF possesses channels decorated by the carbonyl groups and rhombicuboctahedral cages, with open CuII sites pointing toward the cage center. The framework exhibits exceptionally high CO2 (46.7 wt % at 273 K and 1 bar) and H2 (2.8 wt % at 77 K and 1 bar) uptake. Furthermore, it displays high selectivities of CO2 adsorption over N2 and CH4 at 298 K.将多种功能基团引入多孔金属有机框架（MOFs），是改善其气体吸附性能的有效策略。本研究合成了一种羰基化四羧酸配体（5,5'-羰基二间苯二甲酸），并基于该配体成功制备了一类带有暴露金属位点的酮功能化MOFs。结构分析显示，该新型MOF具有由羰基修饰的孔道与小斜方截半立方笼，且开放Cu(II)位点指向笼中心。该框架材料展现出极高的CO₂与H₂吸附量：在273 K、1 bar条件下CO₂吸附量为46.7 wt%，77 K、1 bar条件下H₂吸附量为2.8 wt%。此外，在298 K下，其对CO₂相较于N₂与CH₄的吸附选择性表现优异。