Sensing Performances of Mixed-Potential Type NOx Sensor Using Metal-Oxide Electrode

The mixed-potential-type NOx sensing cells using yttria-stabilized zirconia and metal-oxide sensing electrode were fabricated and examined for an evaluation of NOx detection performance. It has been found that Cr2O3 electrode gives the highest sensitivity among metal oxides examined. Furthermore, ZrO2-laminated-type NOx sensor using Cr2O3 electrode was fabricated and evaluated. This type of sensor has showed excellent performances of detecting low NOx concentration of 10 ppm and little interference by HC and CO. The results indicate that the sensor has great possibility of being utilized as an on-board NOx sensor.