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.