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

摘要

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 cm(3) 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 % RH, providing a record polymer-grade C2H4 productivity of 0.98 mmol g(-1).