Electrochemical NO(sub x) Sensors for Automotive Diesel Exhaust

摘要

Increasingly stringent emissions regulations will introduce a need for compact, inexpensive sensors for monitoring and control of regulated exhaust gas pollutants including hydrocarbons, carbon monoxide, and oxides of nitrogen (NO(sub x)). Significant progress as been made towards the development of electrochemical sensors using ionically conducting ceramic electrolytes, usually yttria-stabilized zirconia (YSZ), and catalytically active metal oxide sensing electrodes. The suitability of numerous single- and mixed-metal oxides for use as NO(sub x) sensor electrodes, usually in air, has been explored in the literature. Despite the prior investigations, however, reliable, cost effective sensors suitable for diesel exhaust gas applications have not yet emerged. Improvements are still needed in sensitivity, response time, reliability, and cross-sensitivity.