Encapsulation of nanoparticles with Xe adsorption sites into MOFs for enhanced Xe/Kr separation

Abstract

Xenon (Xe) and krypton (Kr) are important gases with significant industrial and medical applications. Metal–organic frameworks (MOFs) are a promising class of sorbent materials for Xe/Kr separation. To enhance the Xe/Kr separation performance of MOFs, we develop a strategy to encapsulate Pt nanoparticles into MOFs to introduce strong Xe adsorption sites. Xe and Kr adsorption and separation studies show that Pt@UiO-66 exhibits 21% higher Xe uptake capacity and a 7% increase in Xe/Kr selectivity compared to UiO-66 due to the introduced Xe adsorption sites, despite the Brunauer–Emmett–Teller (BET) surface area decreasing. These findings have led to an 88% extension of column breakthrough time during Xe/Kr separation under identical conditions. We further demonstrate that this approach can be extended to other MOFs with potential for Xe/Kr separation.