Comprehensive Pore Tuning in an Ultrastable Fluorinated Anion Cross‐Linked Cage‐Like MOF for Simultaneous Benchmark Propyne Recovery and Propylene Purification

Abstract Propyne/propylene (C3H4/C3H6) separation is an important but challenging industrial process to produce polymer‐grade C3H6and recover high‐purity C3H4. Herein, we report an ultrastable TiF62−anion cross‐linked metal–organic framework (ZNU‐2) with precisely controlled pore size, shape and functionality for benchmark C3H4storage (3.9/7.7 mmol g−1at 0.01/1.0 bar and 298 K) and record high C3H4/C3H6(10/90) separation potential (31.0 mol kg−1). The remarkable C3H4/C3H6(1/99, 10/90, 50/50) separation performance was fully demonstrated by simulated and experimental breakthroughs under various conditions with excellent recyclability and high productivity (42 mol kg−1) of polymer‐grade C3H6from a 1/99 C3H4/C3H6mixture. A modelling study revealed that the symmetrical spatial distribution of six TiF62−on the icosahedral cage surface provides two distinct binding sites for C3H4adsorption: one serves as a tailored single C3H4molecule trap and the other boosts C3H4accommodation by cooperative host–guest and guest–guest interactions.