A robust metal-organic framework with guest molecules induced splint-like pore confinement to construct propane-trap for propylene purification

It is an extremely challenging task to capture C3H8 from the C3H8/C3H6 mixture, which requires an adsorbent with a specific pore structure. Herein, an ultramicroporous pillared metal–organic framework Ni(ADC)(TED)0.5 is reported for efficient C3H8/C3H6 separation. Theoretical calculations revealed that the ADC ligand may form a splint-like pore confinement structure induced by the introduction of guest molecules to construct a propane-trap in the framework. As a result, excellent separation performance for C3H8/C3H6 is obtained. A record-high IAST-predicted selectivity (6.4), C3H8/C3H6 uptake ratio (111.0%), C3H8 Henry constant (2159.2 mmol g−1 bar−1), and separation potential (1943.0 mmol L-1) exceed those in porous adsorbents reported so far. Breakthrough experiments indicate that Ni(ADC)(TED)0.5 can completely separate C3H8/C3H6 mixture with the highest C3H6 productivity (0.085 mmol g−1) and good regenerability. These results show that this material has great potential application in C3H8/C3H6 separation.