Template-assisted Preparation of Self-standing 2D-MOF Membranes for Application in Cascade Reactions

Abstract

Self-standing metal-organic framework (MOF) membranes open up several application areas where their use in the powder form is either not possible or non-sustainable. Most MOF membranes are prepared as a thin layer either on a supporting substrate or used as a composite membrane with additional supporting material. In this work, we present the preparation procedure for making highly stable, easy-to-handle, reusable, efficient pure MOF membranes (UiO-66-SO3H and UiO-66-NH2 membranes; thickness 240±12 μm and 265±10 μm, respectively) with hollow fiber morphology and their use in cascade reactions in one-pot catalyzed by incompatible acid-base in tea-bag-type concept. The catalytic performance of the catalyst membranes was tested by reacting benzaldehyde dimethyl acetal with three active methylene compounds. The membranes exhibited excellent catalytic activity in cascade reactions in one pot (the yield of the product was as high as 99.9 %) and can be reutilized up to 15 times without any significant loss in activity. Stable pure MOF membranes, as shown in this work, would be of interest for several other applications beyond catalysis.