High-selectivity mixed-potential NO2 sensor incorporating Au and CuO + CuCr2O4 electrode couple

A solid-state planar sensor consisting of scandia-stabilised zirconia (8 mol% Sc2O3–ZrO2) solid electrolyte sandwiched between CuO + CuCr2O4 mixed-oxide and Au foil electrodes has been tested in NO2 containing gaseous atmosphere in the range of 100–500 ppm NO2 at 611 and 658 °C. The sensor has been found to respond consistently to change in concentration of NO2 in the oxygen rich gas mixture at 611 and 658 °C within 8 s. The sensor showed negligible cross-sensitivity to O2, CO and CH4 in the gas stream at 611 °C and 658 °C.