High-Entropy Zeolitic Imidazolate Frameworks for Dynamic Hydrogen Isotope Separation

Abstract

Entropy-driven strategy enables the systematic design ofcomplex systems by using entropy as a quantifiable design parameterfor the degree of mixing. In this study, we present mixed-linker zeoliticimidazolate frameworks (ZIFs), sod-ZIF-1 series, that features twotypes of six-membered rings (6MRs) with aperture sizes of 3.4 Å and1.7 Å . By adjusting the configurational entropy, the ratio of these6MRs can be systematically controlled, which significantly influencesadsorptive properties, particularly improving the H2 affinity about 3times throughout the series. This results in the significantenhancement of retention times in dynamic separation of hydrogenisotopes (D2/H2), even over LNG liquefaction temperature. Thisapproach to entropy-driven pore engineering provides newopportunities for enhancing gas adsorption and separation processes.