Electro-catalytic effect of manganese oxide on oxygen reduction at teflonbonded carbon electrode

Abstract

Abstract Oxygen reduction(OR)on Teflon-bonded carbon electrodes with manganese oxide as catalyst in 6 mol/L KOH solution was investigated using AC impedance spectroscopy combined with other techniques. For OR at this electrode, the Tafel slope is −0.084 V/dec and the apparent exchange current density is (1.02–3.0) × 10 −7 A/cm 2. In the presence of manganese oxide on carbon electrode, the couple Mn 3+/Mn 4+ reacts with the O 2 adsorbed on carbon sites forming O 2 − radicals and acceletes the dismutation of O 2 −, which contributes to the catalytic effect of manganese oxide for OR reaction.