Development of ethane-selective porous materials for highly efficient ethane/ethylene (C 2 H 6 /C 2 H 4 ) separation can energy-efficiently produce high-purity C 2 H 4 in one step. Microporous metal−organic frameworks (MOFs) show great promise as ethane-selective materials; however, achieving both high C 2 H 6 capacity and high C 2 H 6 /C 2 H 4 selectivity in most reported MOFs remains a significant challenge. Herein, we report, for the first time, the strategy of designing V-shaped pore structure with multiple binding sites in an Al-MOF (CAU-8-ODB) to target both high C 2 H 6 uptake and selectivity for highly efficient C 2 H 6 /C 2 H 4 separation. This V-shaped micropore configuration not only enables a large number of inert phenyl rings surrounding the cage to provide stronger interactions with C 2 H 6 over C 2 H 4 , but also provides enough pore spaces to take up large amount of C 2 H 6 . Gas adsorption studies reveal that CAU-8-ODB exhibits a combination of both large C 2 H 6 adsorption capacity (3.30 mmol g −1 at 0.5 bar) and high C 2 H 6 /C 2 H 4 selectivity (2.2) at 296 K and 1 bar, outperforming or comparable to most of top-performing materials reported. Theoretical calculations indicate that the V-shaped cavities with suitable pore spaces can provide stronger multipoint interactions with C 2 H 6 than C 2 H 4 , accounting for both high C 2 H 6 uptake and selectivity. The actual separation capacity of CAU-8-ODB was further testified by the breakthrough experiments for 50/50 (v/v) C 2 H 6 /C 2 H 4 mixtures, affording a remarkably high C 2 H 4 productivity of 15.1 L kg −1 with high purity of 99.95% under ambient conditions.
Wen et al. (Sun,) studied this question.