Electrochemical reduction of oxygen and nitric oxide at low temperature on La1−xSrxMnO3+δ cathodes

Six La1−xSrxMnO3+δ (x = 0, 0.05, 0.15, 0.25, 0.35, 0.50) perovskites were synthesised and characterised by powder XRD and cyclic voltammetry on cone-shaped electrodes in 10% oxygen in argon or 1% nitric oxide in argon at 200, 300 and 400 °C. The activity of the manganite based perovskites were highest in the nitric oxide containing atmosphere compared to the activity in the oxygen containing atmosphere at 200 °C. At 300 and 400 °C the activity in the nitric oxide and oxygen containing atmospheres were similar. The highest ratio between the cathodic current densities in the nitric oxide and oxygen containing atmospheres was found for the La0.95Sr0.05MnO3+δ perovskite at 200 °C.