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 Cu-II sites pointing toward the cage center. The framework exhibits exceptionally high CO2 (46.7 wt % at 273 K and 1 bar) and H-2 (2.8 wt % at 77 K and 1 bar) uptake. Furthermore, it displays high selectivities of CO2 adsorption over N-2 and CH4 at 298 K.