Stabilized zirconia-based sensors using WO3 electrode for detection of NO or NO2

A stabilized zirconia-based electrochemical device, the sensing electrode of which was provided with a single-metal oxide, was tested for detection of NO and NO2 at high temperature, Among the many single-metal oxides examined, WO3 was found to give the best sensing properties to NO and NO2 at 500–700°C. The EMF response of the WO3-attached device was almost linear to the logarithm of NO or NO2 concentration. It also gave speedy response and recovery kinetics to NO or NO2. The device gave very small cross-sensitivities to H2, CO, CH4, CO2 and water vapor.