Enhanced proton conductivity of Mo154-based porous inorganic framework

The construction of inorganic porous frameworks from discrete polyoxometalate (POM) units is a major research challenge. Herein, a three-dimensional (3D) all-inorganic porous structure {Mo154}n that consists of classic Mo154 rings connected by Mo-O-Mo covalent bonds was synthesized. Interestingly, the proton conductivity of the 3D-{Mo154}n framework is 1.1×10−2 S cm−1 at 22 °C and 100% relative humidity (RH), which is one of the highest proton conductivities reported thus far for POM-based conductive materials. Compared to the discrete {Mo154} cluster and 1D-{Mo154}n, the enhanced conductivity of 3D-{Mo154}n suggests that assembling POM-based all-inorganic porous frameworks is a promising method for designing proton-conductive materials.