High-temperature hydrocarbon sensors based on a stabilized zirconia electrolyte and metal oxide electrodes

The sensing properties of zirconia-based electrochemical cells with various metal oxide electrodes for 0-500 ppm hydrocarbons (primarily propene), hydrogen, and carbon monoxide were studied in the presence of 10% oxygen at 600 degrees C. The addition of 0.1 wt % manganese oxide (MnO2) to an indium oxide (In2O3) electrode significantly improved the selectivity of the parent electrode to propene over hydrogen and carbon monoxide. This addition effect was based on the promotion of nonelectrochemical oxidations of hydrogen and carbon monoxide in preference to that of propene. The sensor using the 0.1 wt % MnO2-added In2O3 electrode was more reproducible and sensitive to the hydrocarbons than that using a gold electrode. (C) 1999 The Electrochemical Society. S1099-0062(99)07-027-3. All rights reserved.