One‐Step Ethylene Purification from Ternary Mixture through Adaptive Recognition Sites

Abstract One‐step adsorptive purification of ethylene (C 2 H 4 ) from ternary mixture comprising of acetylene (C 2 H 2 ), ethylene (C 2 H 4 ) and carbon dioxide (CO 2 ) is a great challenge in the chemical industry. Herein, a microporous metal–organic framework ( FJI‐H38) has been reported, which possesses high‐density electronegative O/N binding sites and appropriate pore size. Notably, at 0.01 bar and 298 K FJI‐H38 shows excellent trapping capability for C 2 H 2 (1.64 mmol/g) and CO 2 (2.33 mmol/g), while the uptake of C 2 H 4 is only 0.41 mmol/g, which endows FJI‐H38 high C 2 H 2 /C 2 H 4 and top‐level CO 2 /C 2 H 4 selectivity simultaneously. Polymer‐grade C 2 H 4 (≥99.95 %) with record‐high productivity can be successfully obtained from ternary C 2 H 2 /CO 2 /C 2 H 4 mixture in one step under various conditions. Even at 318 K, the separation performance has no obvious decrease. Such excellent separation performance is due to the adaptive recognition of C 2 H 2 and CO 2 by FJI‐H38 through the synergistic effect of appropriate pore size and the match of electrostatic potentials, where C 2 H 2 and CO 2 can be stabilized by the O/N and aromatic ring sites.