Computational Assessment of Zeolitic-Imidazolate Frameworks (ZIFs) for Adsorption and Diffusion Based Separation of Noble Gas Mixtures

Abstract

Zeolite imidazolate frameworks (ZIFs) possess exceptional chemical and thermal stabilities together with tunable pore sizes, high porosities, and large surface areas which opens new and exciting application areas of ZIFs, such as gas separation and purification. Although, there have been significant number of studies investigating syngas separation performances of ZIFs, currently very little is know about their noble gas separation performances. We, therefore, computationally investigate adsorption and membrane oriented Xe/Kr and Xe/Ar separation performances of ZIF-6, ZIF-60, ZIF-65, and ZIF-79. Single component and mixture gas uptakes, Xe adsorption selectivities, gas permeabilities, and Xe permeation selectivities are predicted for all ZIFs under consideration. Our results suggest that while ZIF-79 is ideal for adsorption-based Xe separation, ZIF-60 can be considered as a promising candidate for membrane oriented separation of Xe.