Shape‐ and Size‐Dependent Kinetic Ethylene Sieving from a Ternary Mixture by a Trap‐and‐Flow Channel Crystal

Abstract Ethylene (C 2 H 4 ) purification from multicomponent mixtures by physical adsorption presents a great challenge in the chemical industry. This work successfully uses the postsynthetic method of crystal transformation in boiling alkaline solution to synthesize a trap‐and‐flow channel crystal (namely NTU‐67), the flow channel of which provides an effective shape‐ and size‐dependent sieving path for linear molecules such as acetylene (C 2 H 2 ) and carbon dioxide (CO 2 ), while the adjacent channel possesses customized space for efficient molecular trapping. The three‐bladed array of the nanospace enables the crystal to afford a record productivity of C 2 H 4 (121.5 mL g −1 , > 99.95%) from C 2 H 2 /CO 2 /C 2 H 4 (1/9/90, v/v/v) mixtures in a single adsorption–desorption cycle under humid and dynamic conditions, even at a high temperature of 343 K and wide gas ratio. The molecular‐level insight and mechanism of the cooperative role of the trap‐and‐flow channel, found computationally and observed experimentally, demonstrates a new design philosophy toward extending the application boundaries of porous coordination polymers to further challenging tasks.