Electrocatalytic activity of perovskite La1−xSrxMnO3 towards hydrogen peroxide reduction in alkaline medium

Perovskite-type series of compounds La_1−xSr_xMnO₃ are synthesized by a sol-gel method using Chitosan as the gelling agent. Their catalytic activity for hydrogen peroxide electroreduction in 3.0 mol dm⁻³ KOH at room temperature is evaluated by means of cyclic voltammetry and chronoamperometry. Effects of annealing temperature and the ratio of La to Sr of La_1−xSr_xMnO₃ on their catalytic performance are investigated. Among this series of compounds, La_0.4Sr_0.6MnO₃ calcined at 650 °C exhibits the highest activity, which is comparable with Co₃O₄. An aluminum-hydrogen peroxide semi-fuel cell using La_0.4Sr_0.6MnO₃ as cathode catalyst achieves a peak power density of 170 mW cm⁻² at 170 mA cm⁻² and 1.0 V running on 0.6 mol dm⁻³ H₂O₂.