Modulation of the Pore Environment in Pillar‐Layered <scp>MOFs</scp> for One‐Step Purification of Ethylene

Comprehensive Summary Due to the extremely similar physical and chemical properties of C 2 H 6 , C 2 H 4 , and C 2 H 2 , purifying ethylene from the C 2 ternary mixture in one‐step is very challenging. In this work, we developed a series of pillar‐layered MOF materials ((Ni(BTC)(Bipy), Ni(BTC)(3‐Me‐Bipy), and Ni(BTC)(3‐NH 2 ‐Bipy)) through the functionalization of pillar ligands using pore engineering strategies. Single‐component adsorption isotherm measurements demonstrate that these materials preferentially adsorb C 2 H 6 and C 2 H 2 , thereby achieving one‐step purification of the three C 2 hydrocarbons to obtain C 2 H 4 . By introducing functional groups on the pillars, the selectivity for C₂H₆/C₂H₄ increased by over 10%, while the selectivity for C₂H₂/C₂H₄ increased by more than 300%. Specifically, Ni(BTC)(3‐NH 2 ‐Bipy) exhibits a selectivity of 1.5 for C 2 H 6 /C 2 H 4 (50/50, V / V ) and 5.16 for C 2 H 2 /C 2 H 4 (1/99, V / V ). Under ambient conditions, the adsorption capacity of Ni(BTC)(3‐NH 2 ‐Bipy) for C 2 H 2 reached 121.6 cm 3 /g, Ni(BTC)(3‐NH 2 ‐Bipy) exhibits superior C 2 H 2 adsorption capacity and C 2 H 2 /C 2 H 4 selectivity compared to many classic materials, including TJT‐100, Azole‐Th‐1, and MOF‐808‐Bzz, commonly used for C 2 H 4 purification from C 2 ternary mixtures. Dynamic breakthrough experiments indicate that in a ternary C 2 mixture, Ni(BTC)(3‐NH 2 ‐Bipy) preferentially captures C 2 H 6 and C 2 H 2 , enabling one‐step purification of C 2 H 4 .