Efficient One-Step Ethylene Purification From Ternary C2 Mixtures via Enhancing Binding Affinity of Heterometallic...

The energy-intensive separation of ethylene from C₂H₂/C₂H₄/C₂H₆ mixtures is an important but challenging industrial process. Herein, we report a synergistic protocol of integrating pore engineering and electrostatic potential regulation on synthesizing MOF for direct C₂H₄ purification from C₂ ternary mixtures under ambient conditions, using a heterometallic MOF (CuCo-1) with Cu₂Co₄ clusters and ethane recognition sites. The synergistic assembly of abundant phenyl rings, pyridyl moieties, and accessible uncoordinated O atoms in CuCo-1 creates a highly selective trapping domain for ethane. Theoretical calculations reveal that its heterometallic clusters alter the electrostatic potential of pore surface because of the charge disparity between Cu and Co as compared with homometallic clusters. Such electrostatic potential change results in not only strong binding affinity for C₂H₆ but also high C₂H₆/C₂H₄ selectivity, which facilitates direct C₂H₄ purification from ternary C₂ mixture. Breakthrough experiments demonstrate that polymer-grade C₂H₄ can be directly obtained from ternary mixtures with a benchmark productivity of 1.17 mmol g^-1 and a record-breaking adsorption capacity efficiency of 63%. This work highlights the pivotal role of heterometallic systems in gas separation.