New advanced in situ carbon monoxide sensor for the process application

Mixed potential solid electrolyte CO sensors with sensing electrodes based on composite with various semiconducting oxides were extensively studied in the temperature range 500–650 °C for sensitivity, stability and cross-sensitivity besides CO to other combustion components like CO2, H2O, O2, and SO2. The highest CO sensitivity was found for the CO sensor with composite electrode based on Au/Ga2O3 showing also good reproducibility and stability in hazardous combustion environment. CO sensor response behavior in non equilibrated oxygen containing gas mixtures is mainly determined by the catalytic activity of the measuring electrode and depends strongly on preparation and measuring conditions. Mixed oxides based on doped chromites show only a little sensitivity to CO. CO sensor based on Au/Ga2O3 composite electrodes was showing good CO selectivity in the presence of other combustion gas species and finally was tested in combustion environment at power plant.