A pillar-layered MOF bearing N/O sites for one-step purification of C2H4 from the mixtures with C2H6 or C3H6

One-step adsorptive separation of high-purity ethylene (C 2 H 4 ) from the mixtures with ethane (C 2 H 6 ) or propylene (C 3 H 6 ) is of crucial importance in the petrochemical industry. Nevertheless, the development of porous materials that possess both high adsorption capacities and selectivities of C 2 H 6 and C 3 H 6 over C 2 H 4 is still a formidable challenge. Herein, we present a microporous pillar-layered metal–organic framework (MOF) that exhibits excellent uptake capacities of C 2 H 6 (4.73 mmol g −1 ) and C 3 H 6 (8.05 mmol g −1 ) at 298 K and 1 bar, leading to high adsorption selectivities for equimolar mixtures of C 2 H 6 /C 2 H 4 (1.6) and C 3 H 6 /C 2 H 4 (16.4), respectively. Breakthrough column experiments demonstrate that the MOF could achieve one-step acquisition of polymer-grade C 2 H 4 (> 99.9 %) during C 2 H 6 /C 2 H 4 and C 3 H 6 /C 2 H 4 separations. Noteworthily, for a C 3 H 6 /C 2 H 4 mixture (2/5, v / v ), high-purity C 2 H 4 (> 99.9 %) and C 3 H 6 (> 99.5 %) can be directly harvested or recovered upon desorption, with high productivities of 86.23 and 31.05 L kg −1 , respectively, surpassing many well-developed adsorbents for C 3 H 6 /C 2 H 4 separation. Theoretical calculations reveal that the nonpolar pore surface bearing accessible N and O atoms affords more hydrogen bonding interactions with C 2 H 6 and C 3 H 6 than C 2 H 4 , accounting for the adsorption affinity in the order of C 3 H 6  > C 2 H 6  > C 2 H 4 . This work may offer valuable insights into the design and construction of high-performance MOFs for one-step C 2 H 4 purification.