Hydrogen gas sensing by sol-gel-derived proton-conducting glass membranes

Abstract

Fast proton-conducting glass was succesfully prepared using the sol-gel method and applied, for the first time, to the hydrogen concentration cell. The porous 5P2O5·95SiO2 glass obtained by heating the gel at 700 °C had a specific surface area of 250 m2/g and exhibited room-temperature conductivities of 6×10-5 and 2×10-2 S/cm under 0.54 and 0.9 water vapor pressure, respectively. These high conductivities are regarded as fast proton conductors accelerated by molecular water bonded to POH groups. The hydrogen concentration cell, where the 5P2O5·95SiO2 glasses were used as membranes, showed Nernstian response to hydrogen pressure.