Hydrogen Sensor Based on YSZ Electrolyte and Tin-Doped Indium Oxide Electrode

A solid-state electrochemical sensor has been developed for hydrogen leak detection in ambient air. The sensor uses an yttria-stabilized zirconia (YSZ) electrolyte with one tin-doped indium oxide (ITO) and one Pt electrode. Excellent sensitivity, and response time , are reported for hydrogen gas in the concentration range of 0.03 to 5.5% in air. Cross-sensitivity to water vapor and are shown to be low. The response to methane, a potentially significant source of interference for such a sensor, is significantly smaller than that for hydrogen. The sensor shows good reproducibility and was unaffected by thermal cycling over the course of this investigation ( of operation). The effects of ITO electrode thickness and thermal aging, and the sensing mechanism, are discussed. The sensor is intended for monitoring potential hydrogen leakage in vehicles powered by hydrogen fuel.