Benchmark single-step ethylene purification from ternary mixtures by a customized fluorinated anion-embedded MOF

Ethylene (C₂H₄) purification from multi-component mixtures by physical adsorption is a great challenge in the chemical industry. Herein, we report a GeF₆^2- anion embedded MOF (ZNU-6) with customized pore structure and pore chemistry for benchmark one-step C₂H₄ recovery from C₂H₂ and CO₂. ZNU-6 exhibits significantly high C₂H₂ (1.53 mmol/g) and CO₂ (1.46 mmol/g) capacity at 0.01 bar. Record high C₂H₄ productivity is achieved from C₂H₂/CO₂/C₂H₄ mixtures in a single adsorption process under various conditions. The separation performance is retained over multiple cycles and under humid conditions. The potential gas binding sites are investigated by density functional theory (DFT) calculations, which suggest that C₂H₂ and CO₂ are preferably adsorbed in the interlaced narrow channel with high aff0inity. In-situ single crystal structures with the dose of C₂H₂, CO₂ or C₂H₄ further reveal the realistic host-guest interactions. Notably, rare C₂H₂ clusters are formed in the narrow channel while two distinct CO₂ adsorption locations are observed in the narrow channel and the large cavity with a ratio of 1:2, which accurately account for the distinct adsorption heat curves.