The effect of temperature and oxygen partial pressure on the reduction mechanism in the Pr2CuO4/Ce0.9Gd0.1O1.95 system

The electrochemical behavior of a porous electrode based on Pr 2 CuO 4 (PCO) screen printed on the surface of Ce 0.9 Gd 0.1 O 1.95 (CGO) solid electrolyte is studied by impedance spectroscopy. The rate-determining stages of the oxygen reduction reaction at the PCO/CGO interface are found for the oxygen partial pressure interval of 30–10 5 Pa and temperatures of 773–1173 K. Changeover of the rate-determining stage of electrode reaction is shown to occur depending on the temperature and the oxygen partial pressure. The PCO electrode polarization resistance is 1.7 Ω cm 2 at 973 K in air and remains constant at thermocycling of the electrochemical cell in the temperature range of 773–1173 K. Based on the found data, PCO can be considered as the promising cathodic material for solid-oxide fuel cells operating at moderate temperatures (773–973 K).