UiO-66 (Zr) MOF as a Promising Material for Butane Isomers Separation: Evidence Based on the Analysis of the Adsorbed Alkanes Mobility by 2H NMR and Molecular Dynamics Simulation

UiO-66 (Zr) is a thermally and chemically stable Zr-based metal–organic framework (MOF) that has proved to be promising for different hydrocarbon separation applications including membrane-based processes. Here, we present a combined experimental ( 2 H NMR) and computational (molecular dynamics simulation) study of the molecular mobility and transport of n -butane and isobutane in the dehydroxylated UiO-66 (Zr) MOF. We show that the microscopic diffusivity D n for n -butane is significantly higher than D iso for isobutane, D n / D iso = 1000 at 300 K with a large difference in diffusion barriers, E n = 25 kJ mol –1 for n- butane and E iso = 50 kJ mol –1 for isobutane. High selectivity for kinetic-driven separation of the n -butane/isobutane mixture in UiO-66 (Zr)-based materials or membranes is expected based on this result.