Customizing Metal‐Organic Frameworks by Lego‐Brick Strategy for One‐Step Purification of Ethylene from a Quaternary Gas Mixture

Abstract One‐step purification of ethylene (C 2 H 4 ) from a quaternary gas mixture of C 2 H 6 /C 2 H 4 /C 2 H 2 /CO 2 by adsorption is a promising separation process, yet developing adsorbents that synergistically capture various gas impurities remains challenging. Herein, a Lego‐brick strategy is proposed to customize pore chemistry in a unified framework material. The ethane‐selective MOF platform is further modified with customized binding sites to specifically adsorb acetylene and carbon dioxide, thus one‐step purification of C 2 H 4 with high productivity of polymer‐grade product (134 mol kg −1 ) is achieved on the assembly of porous coordination polymer‐2,5‐furandicarboxylic acid (PCP‐FDCA) and PCP‐5‐aminoisophthalic acid (IPA‐NH 2 ). Computational studies verify that the low‐polarity surface of this MOFs‐based platform provides a delicate environment for C 2 H 6 recognition, and the specific binding sites (FDCA and IPA‐NH 2 ) exhibit favorable trapping of C 2 H 2 and CO 2 via CH δ+ ···O δ− and C δ+ ···N δ− electrostatic interactions, respectively. The proposed Lego‐brick strategy to customize binding sites within the MOFs structure provides new ideas for the design of adsorbents for compounded separation tasks.