High Propylene Selective Metal-Organic Framework Membranes Prepared in Confined Spaces via Convective Circulation Synthesis

In this study, the successful preparation of defect-free metal-organic framework (MOF) membranes on the inner surface of ceramic hollow fibers and micromonoliths is reported for the first time. The prepared zeolitic imidazolite framework-8 membranes exhibit impressively high propylene/propane (C₃H₆/C₃H₈) separation factor (up to 139), which is over an order of magnitude higher than that of traditional polymeric membranes. Such excellent results are achieved via a versatile convective circulation method, which eliminates the need of pumps for materials supply and is cost effective andenergy efficient. The MOF membranes prepared in this study show the potential in meeting stringent industrial requirements, as they have full protection from external impact during storage and module assembly, as well as high membrane surface area per volume, enabling compact devices for process intensification.