Dense Packing of Acetylene in a Stable and Low-Cost Metal-Organic Framework for Efficient C2H2/CO2 Separation

Porous materials for C2H2/CO2 separation mostly suffer from high regeneration energy, poor stability, or high cost that largely dampen their industrial implementation. A desired adsorbent should have an optimal balance between excellent separation performance, high stability, and low cost. We herein report a stable, low-cost, and easily scaled-up aluminum MOF (CAU-10-H) for highly efficient C2H2/CO2 separation. The suitable pore confinement in CAU-10-H can not only provide multipoint binding interactions with C2H2 but also enable the dense packing of C2H2 inside the pores. This material exhibits one of the highest C2H2 storage densities of 392 g L-1 and highly selective adsorption of C2H2 over CO2 at ambient conditions, achieved by a low C2H2 adsorption enthalpy (27 kJ mol(-1)). Breakthrough experiments confirm its exceptional separation performance for C2H2/CO2 mixtures, affording both large C2H2 uptake of 3.3 mmol g(-1) and high separation factor of 3.4. CAU-10-H achieves the benchmark balance between separation performance, stability, and cost for C2H2/CO2 separation.