Comprehensive Pore Tuning in an Ultrastable Fluorinated Anion Cross‐Linked Cage‐Like MOF for Simultaneous Benchmark Propyne Recovery and Propylene Purification
Yunjia Jiang, Jianbo Hu, Lingyao Wang, Wanqi Sun, Nuo Xu, Rajamani Krishna, Simon Duttwyler, Xili Cui, Huabin Xing, Yuanbin Zhang
Abstract
Abstract Propyne/propylene (C 3 H 4 /C 3 H 6 ) separation is an important but challenging industrial process to produce polymer‐grade C 3 H 6 and recover high‐purity C 3 H 4 . Herein, we report an ultrastable TiF 6 2− anion cross‐linked metal–organic framework (ZNU‐2) with precisely controlled pore size, shape and functionality for benchmark C 3 H 4 storage (3.9/7.7 mmol g −1 at 0.01/1.0 bar and 298 K) and record high C 3 H 4 /C 3 H 6 (10/90) separation potential (31.0 mol kg −1 ). The remarkable C 3 H 4 /C 3 H 6 (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 C 3 H 6 from a 1/99 C 3 H 4 /C 3 H 6 mixture. A modelling study revealed that the symmetrical spatial distribution of six TiF 6 2− on the icosahedral cage surface provides two distinct binding sites for C 3 H 4 adsorption: one serves as a tailored single C 3 H 4 molecule trap and the other boosts C 3 H 4 accommodation by cooperative host–guest and guest–guest interactions.