Material Influence on Characteristics of Zeolite Based Hydrocarbon Gas Sensor

Titelangaben

Dubbe, Andreas ; Moos, Ralf:
Material Influence on Characteristics of Zeolite Based Hydrocarbon Gas Sensor.
2007
Veranstaltung: 16th International Conference on Solid State Ionics , 01.-06.07.2007 , Shanghai, China.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung , Sonstige Präsentationstyp)

Angaben zu Projekten

Abstract

Potentiometric solid electrolyte gas sensors are well known for their fast and reproducible response characteristics, in general independent on the microstructure. Various gases can be detected with this sensor principle by using specific sensitive materials. We have suggested ion conducting zeolites as sensitive materials for potentiometric hydrocarbon gas sensors. The zeolite ZSM-5 is moderately ion conductive and adsorbs gases in its micropores. A sensor using this material showed a reversible and not too slow voltage response to alkanes . However, sensitivity decreased and finally approached zero for alkane concentrations below certain limit values. This was explained with a mechanistic model in which a change of Na+ ion activity due to alkane sorption is assumed as a cause for the potential change. In the present contribution, we report on the influence of zeolite material composition on sensing characteristics for C3H8, down to 100 ppm concentration. The aim was to further clarify the sensing mechanism and to improve the sensitivity in the low-concentration range.