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 (C2F6) from tetrafluoromethane (CF4). 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 C2F6 dense-packing accommodation mode while weakening the CF4 affinity due to the reduced host-guest interactions. Simultaneously enhanced C2F6 adsorption and reduced CF4 adsorption are achieved, resulting in record-high low-pressure C2F6 uptake and C2F6/CF4 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 C2F6/CF4 separation performance is achieved, as demonstrated by the unprecedented electronic-grade (over 99.999%) CF4 productivity (401 L kg-1) obtained from an industrially relevant C2F6/CF4 (3:97) mixture, as well as the excellent water/air/heat stability and recyclability.
Keywords: adsorption; divergent regulation; gas separation; metal–organic frameworks; perfluorocarbons.
© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.