A Rod-Packing Hydrogen-Bonded Organic Framework with Suitable Pore Confinement for Benchmark Ethane/Ethylene Separation

For the separation of ethane from ethylene, it remains challenging to target both high C₂H₆ adsorption and selectivity in a C2H6-selective material. Herein, we report a reversible solid-state transformation in a labile hydrogen-bonded organic framework to generate a new rod-packing desolvated framework (ZJU-HOF-1) with suitable cavity spaces and functional surfaces to optimally interact with C₂H₆. ZJU-HOF-1 thus exhibits simultaneously high C₂H₆ uptake (88 cm³ g^-1) at 0.5 bar and 298 K) and C₂H₆/C₂H₄ selectivity (2.25), which are significantly higher than those of most top-performing materials. Theoretical calculations revealed that the cage-like cavities and functional sites synergistically ``match'' better with C₂H₆ to provide stronger multipoint interactions with C₂H₆ than C₂H₄. In combination with its high stability and ultralow water uptake, this material can efficiently capture C₂H₆ from 50/50 C₂H₆/C₂H₄ mixtures in ambient conditions under 60 providing a record polymer-grade C₂H₄ productivity of 0.98 mmol g^-1.