MOF–polymer mixed matrix membranes for advanced gas separation: Progress, challenges, and future perspectives

Abstract

Membranes have attracted remarkable interest in gas separation technology for industrial sustainability because of their low cost and energy requirements. Their application is quite useful for gas purification and carbon capture to enable hydrogen recovery and to create a hydrogen-based society and a carbon-free future. Conventional membranes, despite being scalable and processable, suffer from a trade-off relation between permeability and selectivity defined by the Robeson upper bound limit. Metal-organic framework (MOF)/Polymer mixed matrix membranes (MMMs) have emerged as a key solution to this limitation. The synergistic combination of the MOF's high molecular sieving properties with a robust and flexible polymer has enhanced the membranes' permeability and selectivity. This review provides a detailed discussion of the membranes, their types, and the major techniques for their fabrication. We have summarised the discussion about the MOFs, their types, synthesis, and various applications and provided our opinion on their classification, synthesis techniques, and performance in the membrane-based gas separation. The review critically analysed the gas separation performance of the MOF-incorporated polymer MMMs over the last few years and discussed the current challenges that make their industrial-scale use difficult. The review concludes by discussing emerging trends, including defect engineering and 2D MOFs, which could transform the use of MOF/polymer MMMs from the laboratory to industrial scale.