A High-Stability Co-MOF with Open Metal Sites for C2H2/CO2/CH4 Separation

One-step purification of C2H2 from ternary mixtures (C2H2, CO2, and CH4) can significantly reduce the energy consumption of the separation process, but it is extremely challenging. A new Co-MOF (TNU-BTTB-1) with a three-dimensional (3D) framework was synthesized, which displays high thermal stability, retaining its structural integrity at temperatures up to 400 °C. The structure possesses rich accessible open metal sites in the porous walls and shows high uptake for C2H2 (37.4 cm3 g–1) and significant adsorption selectivity for C2H2 over CH4 (20.1) and CO2 (4.9) at 298 K and 100 kPa. Dynamic breakthrough studies show that it exhibits excellent C2H2 separation from C2H2/CO2/CH4 three-component mixtures.