Optimizing the Microenvironment of Pores in an MOF for Boosting Ethylene Purification from a Ternary-Component Mixture

Designing an adsorbent that can simultaneously trap acetylene (C2H2) and ethane (C2H6) impurities for the one-step purification of ethylene (C2H4) remains a challenge. Herein, we constructed a novel Cu-based metal–organic framework (MOF), BUT-321, which exhibits the selective adsorption of C2H2 and C2H6 over C2H4. It was found that the high density of oxygen binding sites within the pore channels of BUT-321 can build an optimal environment for stronger interactions with C2H6, compared to the isostructural MOF BUT-320. Column breakthrough experiments confirm the exceptional C2H4 separation performance of BUT-321 from both binary (1:1 for C2H2/C2H4 or C2H6/C2H4) and ternary (1:1:1 for C2H2/C2H4/C2H6) gas mixtures in a single step. In addition, BUT-321 exhibits good chemical stability in water and an alkaline solution, combined with its synthesis scalability, economic viability, and recyclability, thus facilitating the application for the one-step C2H4 purification.