Metal–Organic Frameworks as a Versatile Platform for Proton Conductors

Metal-organic frameworks (MOFs) are an intriguing type of crystalline porous materials that can be readily built from metal ions or clusters and organic linkers. Recently, MOF materials, featuring high surface areas, rich structural tunability, and functional pore surfaces, which can accommodate a variety of guest molecules as proton carriers and to systemically regulate the proton concentration and mobility within the available space, have attracted tremendous attention for their roles as solid electrolytes in fuel cells. Recent advances in MOFs as a versatile platform for proton conduction in the field of humidity condition proton-conduction, anhydrous atmosphere proton-conduction, single-crystal proton-conduction, and including MOF-based membranes for fuel cells, are summarized and highlighted. Furthermore, the challenges, future trends, and prospects of MOF materials for solid electrolytes are also discussed.