Effects of Sr addition to La-based perovskite sensing-electrode on YSZ-based amperometric-type NOx sensor

Abstract

Sensing characteristics of amperometric NOx sensor using yttria-stabilized zirconia (YSZ) and La-based perovskite-type oxide sensing-electrode (SE) was examined. La0.8Sr0.2MO3(MCo, Mn, Fe) and LaMnO3 was synthesized by means of spray pyrolysis method. The sensor attached with La0.8Sr0.2MnO3 as a SE showed the highest occupancy rate of NO2 response in total current as well as low current response to CO, C3H6, NH3 at 600°C in O2 (21%). The response was increased with increasing NO2 concentration in the examined range between 50 to 800 ppm. The comparison of sensing property between LaMnO3-SE and La 0.8Sr0.2MnO3-SE showed the substitution Sr for La improved the NO2 response for the sensors. © 2011 Ceramic Society of Japan.