Electro-catalytic effect of manganese oxide on oxygen reduction at teflonbonded carbon electrode
(School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China)
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)×10P－7P A/cmP2P. In the presence of manganese oxide on carbon electrode, the couple MnP3+P/MnP4+P reacts with the OB2B adsorbed on carbon sites forming radicals and acceletes the dismutation of , which contributes to the catalytic effect of manganese oxide for OR reaction.
Key words: oxygen reduction; manganese oxide; gas diffusion electrode; AC impedance