Abstract
Efficient separation of Xenon (Xe) and krypton (Kr) is important in the gas industries but remains challenging. Adsorptive separation affords an energy-efficient method to isolate the two noble gases, yet developing selective adsorbents with high uptake and excellent selectivity remains difficult, limited by a trade-off between uptake and selectivity. We report MOF-11 with optimal pore size and accessible open metal sites (OMSs) for separation of Xe over Kr via the discriminable difference in van der Waals interactions. MOF-11 affords a new benchmark for Xe/Kr separation with high Xe uptakes of 4.05 and 4.95 mmol/g (at 0.2 and 1 bar), high Xe/Kr Henry and IAST selectivity (13.6 and 16.1) at 298 K. Evidenced by Xe-loaded structure, multiple Xe···H interactions between Xe and the terminal H atoms allow Xe atoms firmly packed within the framework. This work demonstrates a strategy for balancing uptake and selectivity in Xe/Kr separation by capitalizing on the synergy between optimal pore size and OMSs.
Original language | English (US) |
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Pages (from-to) | 120932 |
Journal | Separation and Purification Technology |
Volume | 291 |
DOIs | |
State | Published - Mar 28 2022 |
Bibliographical note
KAUST Repository Item: Exported on 2022-04-18Acknowledgements: The authors gratefully acknowledge support from the National Natural Science Foundation of China (Nos. 22108141, 21878101, 21808067, 21706031), Natural Science Foundation of Shandong Province (ZR2021QB013 and ZR2020QB033), Guangdong Natural Science Foundation (2019A1515010692), China Postdoctoral Science Foundation (2018 M640785), Guangdong Basic and Applied Basic Research Foundation (2019A1515011512, 2021A1515010172).