Introducing local-molecule trap in a cost-effective metal-organic framework for C2H2/CO2 separation

Adsorption -based C2H2 purification is a promising technology in the petrochemical industry, but the seeking or design of suitable adsorbents faces the challenge of merging excellent separation properties with other implementable advantages. Here, we reported a cost-effective and easily scalable metal-organic framework (MOF), BUT-316-a (BUT = Beijing University of Technology), with unprecedented local-molecule-trap (LMT) for the preferential adsorption of C2H2 over CO2. Attributed to the existence of the LMT, high density of open metal sites (OMSs), and microporous pore structure, BUT-316-a combines high uptake (117.6 cm3 cm -3) and packing density of C2H2 (0.36 g mL-1), coupled with good C2H2/CO2 selectivity (17.2). The practical separation performance of BUT-316-a toward C2H2/CO2 mixture and the associated host-guest interactions within the LMT were further unveiled by dynamic breakthrough experiments and theoretical calculations, respectively. This study may provide valuable insights into designing more advanced adsorbents with an optimal binding environment for gas separation.