A dc polarographic study of the reduction of oxygen catalyzed by adsorbed Pb(II) species

Abstract

The enhancement of the dc polarographic reduction current of oxygen by adsorbed Pb(II) species first observed by Strnad in 1939 and later studied qualitatively by a number of other authors has been reconsidered both experimentally and theoretically.

A number of possible reaction mechanisms is considered. The experimental results obtained in this work could be fitted well only to one of these mechanisms. It is concluded that the activation energy of the electrochemical reduction of H2O2 to OH− ions is lowered by an amount proportional to the surface excess of the Pb(II) species and that the participation of a Pb(II)−Pb(IV) oxidation-reduction cycle should be regarded as disproved.