High temperature fiber-optic evanescent wave hydrogen sensors using La-doped SrTiO3 for SOFC applications

Abstract Advanced sensors are needed for development of next-generation fossil fuel power generation technologies and for enhancing efficiencies of existing power generation systems. Optical waveguide-based sensing technologies have become increasingly important for harsh environment energy applications. In this manuscript, we present sensing results for fiber-optic evanescent wave hydrogen sensors employing La-doped SrTiO 3 layers as the active sensing element. These sensors show a rapid, reproducible sensing response to hydrogen fuel gas streams at elevated temperatures (600–800 °C). The presence of hydrogen results in a reversible and reproducible decrease in near-infrared transmission through the sensor. Sensors were also tested directly in the anode assembly of an operating solid oxide fuel cell (SOFC) with the sensor response correlating with both H 2 concentration and SOFC cell potential.