Inorganic Electrolyte Membrane for High-temperature PEM fuel cell: Conception, Preparation and Performance

Abstract

A novel conception of inorganic proton exchange membrane for elevated temperature PEM fuel cell was proposed in this research. The inorganic electrolyte was approached by trapping heteropolyacid (HPA) molecules inside mesoporous silica structure via a self-assembly route assisted with a structure-directing surfactant, and then construct an inorganic membrane based on mesoporous silica matrix and HPA proton conducting sites. Such mesoporous HPA/silica significantly enhance the stability of HPA molecules, and provided continuous proton transfer channels with diameter of 3~4 nm, resulting high proton conductivity of about 0.05 S/cm at 300oC. A PEMFC based on the mesoporous HPA/silica inorganic PEM and a non-platinum cathode catalyst achieved a power density of 102 mW/cm2 at 300oC, closing to the performance of the cell with Pt catalyst at temperature of 80 oC.