Simultaneous Trapping of C₂H₂ and C₂H₆ from a Ternary Mixture of C₂H₂/C₂H₄/C₂H₆ in a Robust Metal–Organic Framework for the Purification of C₂H₄

Abstract

Abstract The removal of C 2 H 2 and C 2 H 6 from C 2 H 4 streams is of great significance for feedstock purification to produce polyethylene and other commodity chemicals but the simultaneous adsorption of C 2 H 6 and C 2 H 2 over C 2 H 4 from a ternary mixture has never been realized. Herein, a robust metal–organic framework, TJT‐100, was designed and synthesized, which demonstrates remarkably selective adsorption of C 2 H 2 and C 2 H 6 over C 2 H 4 . Breakthrough experiments show that TJT‐100 can be used as an adsorbent for high‐performance purification of C 2 H 4 from a ternary mixture of C 2 H 2 /C 2 H 4 /C 2 H 6 (0.5:99:0.5) to afford a C 2 H 4 purity greater than 99.997 %, beyond that required for ethylene polymerization. Computational studies reveal that the uncoordinated carboxylate oxygen atoms and coordinated water molecules pointing towards the pore can trap C 2 H 2 and C 2 H 6 through the formation of multiple C−H⋅⋅⋅O electrostatic interactions, while the corresponding C 2 H 4 –framework interaction is unfavorable.