Amino-functionalized Metal-Organic Framework for Efficient Separation of Xenon/Krypton

Abstract

The separation of xenon and krypton is an important yet energy-intensive industrial process. Adsorptive separation based on adsorbents like metal-organic frameworks (MOFs) is of great interests regarding its tremendous energy-saving. Herein, we report a new copper nicotinate MOF with free amino groups for highly efficient Xe/Kr separation. This MOF shows twofold interpenetrated dia topology with relatively compact pore structure (4.6 × 5.9 Ų). Single-component adsorption isotherms revealed that this MOF exhibits simultaneously high Xe uptake capacity at low pressure (2.71 mmol g⁻¹ at 20 kPa) and selectivity (18.6), which is comparable to reported benchmark MOF materials. Structural modelling study indicates that the incorparation of amino functional groups enhances the binding affinity of MOF for Xe. Breakthrough experiments confirmed that this material can efficiently separate Xe and Kr (purity >99.9%) from Xe/Kr mixture (20/80, v/v).