Working mechanism of an ethanol filter for selective high-temperature methane gas sensors

Kerstin Wiesner, Helmut Knözinger, Maximilian Fleischer, Hans Meixner

Research output: Contribution to journalArticle

6 Citations (Scopus)


Semiconducting metal-oxide gas sensors are generally nonselective, which limits their use as natural gas detectors in domestic environments when ethanol is present in high background concentrations. Using a thin-film Ga 2O3 sensor with a thick-film catalyst filter of Ga 2O3 and an operating temperature of 800°C, the cross-sensitivity to ethanol is strongly reduced and the sensor response to methane is enhanced. Detection of natural gas is made reliable and the rate of false alarms is reduced. Oxidation of ethanol and methane over gallium oxide are studied using GC product analysis. These measurements of catalytic activity help to clarify the reactions involved in the filtering mechanism. Elimination of the ethanol cross-sensitivity is attributed to the thermal combustion of ethanol as it passes over the hot filter. The sensor response to methane is enhanced as methane is activated by the active catalytic Ga2O 3 thick-film.

Original languageEnglish
Pages (from-to)354-359
Number of pages6
JournalIEEE Sensors Journal
Issue number4
Publication statusPublished - Dec 1 2002



  • Catalyst
  • Ethanol filter
  • Gallium oxide
  • Methane sensor
  • Selectivity

ASJC Scopus subject areas

  • Instrumentation
  • Electrical and Electronic Engineering

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