Electrochemical NOx Sensor for Monitoring Diesel Emissions

Increasingly stringent emissions regulations will require the development of advanced gas sensors for a variety of applications. For example, compact, inexpensive sensors are needed for detection of regulated pollutants, including hydrocarbons (HCs), CO, and NO(sub x), in automotive exhaust. Of particular importance will be a sensor for NO(sub x) to ensure the proper operation of the catalyst system in the next generation of diesel (CIDI) automobiles. Because many emerging applications, particularly monitoring of automotive exhaust, involve operation in harsh, high-temperature environments, robust ceramic-oxide-based electrochemical sensors are a promising technology. Sensors using yttria-stabilized zirconia (YSZ) as an oxygen-ion-conducting electrolyte have been widely reported for both amperometric and potentiometric modes of operation. These include the well-known exhaust gas oxygen (EGO) sensor. More recently, ac impedance-based (i.e., impedance-metric) sensing techniques using YSZ have been reported for sensing water vapor, hydrocarbons, CO, and NO(sub x). Typically small-amplitude alternating signal is applied, and the sensor response is measured at a specified frequency. Most impedance-metric techniques have used the modulus (or magnitude) at low frequencies (< 1 Hz) as the sensing signal and attribute the measured response to interfacial phenomena.

• Record URL:
  https://e-reports-ext.llnl.gov/pdf/367821.pdf
• 
• Corporate Authors:

  Lawrence Livermore National Laboratory

  7000 East Avenue
  Livermore, CA  United States  94550

  Department of Energy

  1000 Independence Avenue, SW
  Washington, DC  United States  20585
• Authors:
  • Woo, L Y
  • Glass, R S
• Publication Date: 2008-11

Language

• English

Media Info

• Media Type: Print
• Pagination: 12p

Subject/Index Terms

• TRT Terms: Air pollution; Air quality management; Diesel engine exhaust gases; Diesel fuels; Environmental impacts; Hydrocarbons; Monitoring; Nitrogen oxides; Sensitivity; Thermodynamics; Water vapor
• Subject Areas: Environment; Highways; Vehicles and Equipment; I15: Environment;

Filing Info

• Accession Number: 01135373
• Record Type: Publication
• Report/Paper Numbers: LLNL-TR-408750
• Files: TRIS
• Created Date: Jul 21 2009 8:11AM