Tailored Synergistic Binding Environment in Metal-Organic Frameworks for Record One-Step Ethylene Purification from...

Precise control over pore environments in porous materials remains a long-standing challenge for efficient ethylene (C₂H₄) purification via physisorption, particularly when targeting impurities with distinct physicochemical properties such as carbon dioxide (CO₂) and ethane (C₂H₆). In this study, we report an isoreticular design strategy to fine-tune the local pore chemistry of metal-organic frameworks (MOFs), enabling the simultaneous selective adsorption of CO₂ and C₂H₆. Through rational organic ligand engineering, the hydroxyl-functionalized analogue PCP-TPA-2OH (also termed as ZU-925, ZU represents Zhejiang University) breaks the bottleneck of only C₂H₆ capture exhibited by the parent PCP-TPA. The tailored synergistic binding environment of ZU-925 makes it be new benchmark in one-step C₂H₄ purification from CO₂/C₂H₆/C₂H₄ ternary mixtures. Ultra-purity C₂H₄ (99.99%) along with high productivity of 17.8 L kg^-1 could be realized through only one-step adsorption. Molecular simulations reveal that the preferential binding of C₂H₆ arises from a tailored pore environment featuring aligned aromatic units and electronegative oxygen atoms, while Lewis basic hydroxyl groups locally modulate the pore chemistry, contributing to enhanced CO₂ capture. This study provides valuable insights into the design of advanced adsorbents for multiple impurity removal via isoreticular chemistry.