INFLUENCE OF OXYGEN ON DETECTION OF NITROGEN-OXIDES WITH SOLID ELECTROLYTE SENSOR USING NANO3

The solid electrolyte sensor device using a sodium ionic conductor and NaNO3 (auxiliary phase) was found to exhibit a remarkable feature that its EMF response to NO2 is totally independent of the concentration of coexisting oxygen. The response to NO, however, was seriously affected by the presence and absence of O2, suggesting the oxidation of NO to NO2 prior to being sensed. In the absence of NOx, the sensor EMF changed with changing oxygen concentration following the Nernst's equation for a 2-electron reaction of O2.