Recent advances in MOFs-based proton exchange membranes

According to the types of organic polymers, the design, preparation, performance and application value of composite membranes using MOFs as fillers were classified and summarized. The future development trends and priorities are also discussed and prospected. • Proton exchange membranes based on MOFs were reviewed. • PEMs are classified in the light of the types of polymeric matrix. • Proton conduction and conductve mechanism were concluded. • The future development trend of such PEMs was highlighted. To overcome the defects of traditional proton exchange membranes (PEMs) (Nafion and Nafion-based membranes, etc.), the introduction of proton-conducting MOFs with performance advantages into the PEM system is a smart strategy, many exciting research results have emerged one after another in recent years. For the convenience of researchers and to explore trends for future development, in this review. MOF-based PEMs are divided into the mixed-matrix membranes using MOFs as fillers and PEMs formed by MOFs directly based on different film-forming methods, and the properties of these PEMs are concluded. The following aspects were focused on the preparation strategies and techniques, stability (covering thermal-, water-, chemical-, and mechanical stabilities, etc.), proton conductive properties under damp or anhydrous conditions, and proton conduction mechanism, and structure–activity relationship. Finally, the prospects and challenges of future research are highlighted.