Divergent Adsorption Regulation in Metal–Organic Frameworks for Highly Efficient CF4/C2F6 Separation

Abstract The efficient removal of low‐concentration components from homologous mixtures is often hampered by the co‐directional effect of traditional thermodynamic regulation approaches, typically leading to a trade‐off between adsorption capacity and selectivity. Focusing this challenge on the critical task of purifying perfluorocarbons in electronics industry, a divergent regulation strategy is reported that significantly improves the separation efficiency of low‐concentration hexafluoroethane (C 2 F 6 ) from tetrafluoromethane (CF 4 ). This approach involves the selective shielding of open metal sites and the modulation of channel geometry within an electron‐deficient ligand‐based pore environment, thereby facilitating a C 2 F 6 dense‐packing accommodation mode while weakening the CF 4 affinity due to the reduced host‐guest interactions. Simultaneously enhanced C 2 F 6 adsorption and reduced CF 4 adsorption are achieved, resulting in record‐high low‐pressure C 2 F 6 uptake and C 2 F 6 /CF 4 selectivity. Comprehensive insights into the unique separation mechanism are illustrated through a combination of solid‐state MAS nuclear magnetic resonance (SSNMR), molecular simulations, and meticulously designed comparative experiments. As a result, benchmark C 2 F 6 /CF 4 separation performance is achieved, as demonstrated by the unprecedented electronic‐grade (over 99.999%) CF 4 productivity (401 L kg −1 ) obtained from an industrially relevant C 2 F 6 /CF 4 (3:97) mixture, as well as the excellent water/air/heat stability and recyclability.