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

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.