Hydrocarbon sensor for automotive exhaust gases with integrated electrochemical cell to adjust oxygen partial pressure

Titelangaben

Biskupski, Diana ; Wiesner, Kerstin ; Moos, Ralf ; Fleischer, Maximilian:
Hydrocarbon sensor for automotive exhaust gases with integrated electrochemical cell to adjust oxygen partial pressure.
2007
Veranstaltung: The 7th East Asian Conference on Chemical Sensors (EACCS 7) , 03.-05.12.2007 , Singapore, Malaysia.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung , Sonstige Präsentationstyp)

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Abstract

In order to improve air quality and to protect environment, emission requirements for automotive exhausts are regulated strictly. A diagnosis system called “On-Board Diagnosis” (OBD) was introduced to meet the demands. OBD includes the monitoring of the catalyst with two Lambda-probes. This conventional technology is an indirect method as it correlates oxygen concentrations with a loss in the oxygen storage capacity of the catalyst. Due to the fact that future emission requirements demand more precise diagnosis, this technology might not be adequate. Hence, it is proposed to apply a direct method to control the catalyst by measuring the amount of unburnt hydrocarbons with a hydrocarbon (HC) sensor for both the gasoline and the diesel engine. Proper sensor materials applied in the rough atmosphere of exhaust gases are semiconducting metal oxides such as SrTiO3 or Ga2O3. These metal oxides show sensitivity towards HCs but also towards changes in the oxygen partial pressure (pO2). As the pO2 varies due to different load and engine speed conditions, the targeted sensor is integrated in an oxygen ion conducting material like in literature to set pO2 in the ambiance of the sensor.