A Stable Sensing-Electrode Material in Reducing Atmosphere at High Temperature for Zirconia-Based Amperometric NOx Sensor

Abstract

La_0.8Sr_0.2Al_1−xMn_xO₃ (x = 0, 0.2, 0.4, 0.6) were synthesized using a spray pyrolysis method as a stable sensing-electrode (SE) material in high-temperature reducing atmosphere for zirconia-based amperometric NOx sensor. The XRD diffraction pattern of the La_0.8Sr_0.2AlO₃ oxide after treatment in a reducing atmosphere (in 4 vol.% H₂ at 750°C for 2 h) was same with the one as-prepared. A response to 500 ppm NO₂ of a sensor using the oxide after treatment as an SE was −1.3 µA, a value approximately equal to that obtained using an oxide before treatment.