Planar, Impedance-Metric NOX Sensor with NiO Sensing Electrode for High Temperature Applications

In this study, an innovative type of sensor configuration is used which contains an electrolyte constructed of quasi-single crystalline columns, a porous NiO sensing electrode (SE) and a conductive Pt reference electrode (RE) deposited on the backside. As electrolyte EB-PVD manufactured discs of FYSZ and PYSZ composition were used. Gas sensing characterization of the sensors was carried with typical flue-gas mixtures in various concentrations. Impedance and potential analysis were done at a frequency range of 100 kHz and 0.005 Hz. Sensors with FYSZ electrolyte could be operated at higher temperatures compared to those with PYSZ electrolytes. The highest achieved sensing temperature in this study was 600degC. NO was successfully detected under the presence of 5%vol. O₂ at the maximum operating temperature.