Pillar-Layered Metal–Organic Framework with Sieving Effect and Pore Space Partition for Effective Separation of Mixed Gas C₂H₂/C₂H₄

The removal of acetylene from the industrial feed gas to purify the ethylene is an important and challenging issue. The adsorption-based separation is a more environmentally friendly and cost-effective method compared to the current removal approaches such as partial hydrogenation and solvent extraction, while facing the challenge of developing materials with high C 2 H 2 /C 2 H 4 selectivity and C 2 H 2 capacity. Herein, by expanding mixed-metal organic frameworks (M’MOFs) structure with high C 2 H 2 /C 2 H 4 selectivity, we report a pillar-layered MOF, {[Cd 5 (MPCZ) 2 (BDC) 3 (NO 3 ) 2 (H 2 O) 4 ]·G} n ( MECS-5 ), which not only inherits the sieving effects of M’MOF series but also develops its own characteristic—the 2D layer with expanding space and the plane pore-partition group to “cover” it. MECS-5 shows higher ideal adsorption solution theory C 2 H 2 /C 2 H 4 selectivity than the most reported MOFs, especially more than 5 times higher than MOF-74 series while displaying great enhancement in the C 2 H 2 capacity, more than 2 times higher compared to the M’MOF. The column breakthrough experiment further proves the possibility of MECS-5a for real industrial ethylene purification.