A Robust Squarate-Based Metal–Organic Framework Demonstrates Record-High Affinity and Selectivity for Xenon over Krypton

Citations Over TimeTop 10% of 2019 papers

Abstract

The efficient separation of xenon (Xe) and krypton (Kr) is one of the industrially important processes. While adsorptive separation of these two species is considered to be an energy efficient process, developing highly selective adsorbent remains challenging. Herein, a rigid squarate-based metal-organic framework (MOF), having a perfect pore size (4.1 Å × 4.3 Å) comparable with the kinetic diameter of Xe (4.047 Å) as well as pore surface decorated with very polar hydroxyl groups, is able to effectively discriminate Xe atoms, affording a record-high Xe/Kr selectivity. An exceptionally high Xe uptake capacity of 58.4 cm3/cm3 and selectivity of 60.6 at low pressure (0.2 bar) are achieved at ambient temperature. The MOF exhibits the highest Xe Henry coefficient (192.1 mmol/g/bar) and Xe/Kr Henry selectivity (54.1) among all state-of-the-art adsorbents reported so far. Direct breakthrough experiments further confirm the excellent separation performance. The density functional theory calculations reveal that the strong interaction between Xe and the framework is a result of the synergy between optimal pore size and polar porosity.

Related Papers

• → Intermolecular interactions and excess thermodynamic properties of argon-krypton and krypton-xenon mixtures(1975)79 cited
• → Use of Noble Gases Xenon and Krypton as Heavy Atoms in Protein Structure Determination(2003)44 cited
• → Detection of krypton in xenon for dark matter applications(2011)32 cited
• → Incommensurate–commensurate transition driven by concentration in rare gas mixtures adsorbed on graphite(1989)7 cited
• → Physical adsorption of gases. Part 2.—Mixture of xenon and krypton on Pyrex(1968)11 cited