Electrocatalytic activity of perovskite La_(1-x)Sr_xMnO_3 towards hydrogen peroxide reduction in alkaline medium

摘要

Perovskite-type series of compounds La_(1-x)Sr_xMnO_3 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-x)Sr_xMnO_3 on their catalytic performance are investigated. Among this series of compounds, La_(0.4)Sr_(0.6)MnO_3 calcined at 650 ℃ exhibits the highest activity, which is comparable with CO_3O_4. An aluminum-hydrogen peroxide semi-fuel cell using La_(0.4)Sr_(0.6)MnO_3 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) H_2O_2.