Ultra-fast Proton Conduction and Photocatalytic Water Splitting in a Pillared Metal-Organic Framework

Proton-exchange membranefuel cells enable the portable utilizationof hydrogen (H-2) as an energy resource. Current electrolyticmaterials have limitation, and there is an urgent need to developnew materials showing especially high proton conductivity. Here, wereport the ultra-fast proton conduction in a novel metal-organicframework, MFM-808, which adopts an unprecedented topology and a uniquestructure consisting of two-dimensional layers of {Zr-6}-clusters.By replacing the bridging formate with sulfate ligands within {Zr-6}-layers, the modified MFM-808-SO4 exhibits anexceptional proton conductivity of 0.21 S & BULL;cm(-1) at 85 & DEG;C and 99% relative humidity. Modeling by molecular dynamicsconfirms that proton transfer is promoted by an efficient two-dimensionalconducting network assembled by sulfate-{Zr-6}-layers.MFM-808-SO4 also possesses excellent photocatalytic activityfor water splitting to produce H-2, paving a new pathwayto achieve a renewable hydrogen-energy cycle.