Producing Gas-selective Electrochemical Microsensors by Tuning Solid Electrolyte Composition

Abstract

Abstract: Monolithic gas sensors, developed at Argonne National Laboratory, employed cyclic voltammetry measurement techniques, YSZ solid electrolyte electrochemical cells and K-nearest neighbor (neural) chemometrics techniques to sense multiple components in a gas mixture. These voltammetry-based devices detected most hydrocarbons, displayed no saturation effects and were functional from < 1 ppm to 100 % oxygen concentrations, but were not sensitive to carbon dioxide due to the lack of reactivity within the Pt electrodes. Investigations revealed that specific CO2 sensitivity could be introduced by adding tungsten stabilized bismuth oxide (WBO) to the solid electrolyte composition while maintaining the same basic sensor geometry and electrode configuration. The YSZ/WBO sensors are functional in a range of CO2 concentrations from low ppm to 100 %.

Keywords

• O2
• CO2
• Thick-film microsensor
• Solid electrolyte
• Gas-phase voltammetry
• WBO