A Highly Connected Trinuclear Cluster Based Metal-Organic Framework For Efficient Separation Of C2h2/C2h4 And C2h2/Co2

One of the barriers for efficient gas separation is the trade-off between the selectivity and adsorption capacity. To address this issue, we synthesized an anionic trinuclear CoII based 3D MOF (NbU-8), which is characterized by an ultramicroporous building unit (UBU) and Lewis basic binding sites on the pore surfaces. Remarkably, the combination of the two strategies can synergistically enhance the C2H2 adsorption capacity (182.9 cm(3)/g at 298 K) and simultaneously achieve a high separation performance toward C2H2/C2H4 and C2H2/CO2 mixtures. Besides theoretical calculations, the separation efficiencies of C2H2/C2H4 and C2H2/CO2 are also demonstrated using breakthrough experiments. Density functional theory calculations have further confirmed the -OH groups and ultramicroporous building units play an important synergistic effect in efficiently capturing acetylene molecules.