Zirconia-based amperometric sensor using ZnO sensing-electrode for selective detection of propene

The sensing characteristics to propene (C3H6) were examined at 600 °C under wet condition for the amperometric sensor using a yttria-stabilized zirconia (YSZ) tube and ZnO (+8.5 wt%Pt) sensing-electrode (SE). In order to improve the sensitivity to C3H6, the “pulsed-potential method” was adopted here. It was found that the current response varied almost linearly with C3H6 concentration in the range of 0–200 ppm when SE was polarized at +1.0 V (vs. Pt/air reference electrode) for a period of 0.3 s. By using the present “pulsed-potential method”, the sensitivity to 100 ppm C3H6 was increased about 1000 times, compared with the normal “constant-potential method”. The excellent selectivity to C3H6 was also obtained for the present sensor without influence of other hydrocarbons, NOx, CO, H2, etc.