Carbon dioxide gas sensor based on trivalent cation and divalent oxide anion conducting solids with rare earth oxycarbonate based auxiliary electrode

A carbon dioxide gas sensor was fabricated by the combination of trivalent Al3+ cation conducting (Al0.2Zr0.8)20/19Nb(PO4)3 and O2− anion conducting yttria stabilized zirconia (YSZ) with the two phase mixture of 0.5(0.8La2O2SO4-0.2Li2CO3) + 0.5(Nd0.47Ba0.12Li0.29)2O0.94CO3 solid as the sensing auxiliary electrode. Since the present sensor shows a quantitative and reproducible response, which exactly obeys the Nernstian theoretical relationship at 500 °C, it is greatly expected that the present sensor would be one of the promising candidates for the practical CO2 sensing devices applicable at intermediate temperature range around 500 °C.