MOF UiO-66 Membranes for Pervaporation Prepared by Secondary Growth Using Zr(n-OPr)4

Abstract

A defect-free and stable metal–organic framework (MOF) membrane is a promising candidate for the separation of methanol/methyl tertiary butyl ether (MeOH/MTBE) mixtures. In this work, a structural-integrity and low-thickness (∼400 nm) UiO-66 membrane was fabricated by regulating the metal ion/ligand molar ratio in the synthesis solution and optimizing the preparation process using the secondary growth method with safer and more environment-friendly Zr(n-OPr)₄ metal source. Based on the effective pore size and inherent amphiphilic structure of UiO-66, the membrane exhibits exceptional pervaporation (PV) performance. For the separation of MeOH/MTBE (5:95 wt/wt %) mixtures, the membrane displays an outstanding separation performance with an average separation factor of 2.23 × 10⁴ and an average total flux of 3.61 kg·m^–2·h^–1 at 40 °C, which is superior to most membranes reported for the PV separation of MeOH/MTBE mixtures. In addition, a 72 h PV process was used to further confirm the structural stability of the membrane.