Designing Metal–Organic Framework (MOF) Membranes for Isomer Separation

Membrane-based separation has the merit of low carbon footprint. In this study, the pore size of metal-organic framework (MOF) membranes is rationally designed for discriminating various pairs of hydrocarbon isomers. Specifically, Zr-MOF UiO-66 (UiO stands for University of Oslo) membranes are developed for separating p/o-xylene due to their proper pore size. For n-hexane/2-methylpentane separation, the functional groups and proportion of the ligands in UiO-66 are gradually adjusted to effectively regulate the pore size, and UiO-66-33Br membranes are constructed. In addition, relying on the utilization of ligands with shorter length, MOF-801 membranes with smaller pore size are fabricated for n/i-butane separation.