The Role of Hydrogen Peroxide in Oxygen Reduction at Platinum in H[sub 2]SO[sub 4] Solution

The rotating disk electrode with a concentric ring is used to analyze the role of in the reduction of O 2 to in acid solutions. No is formed as an intermediate in the reaction path of oxygen reduction to water. Only when the residual impurities from the not sufficiently purified solutions are adsorbed at the electrode does a parallel reaction path appear in which is formed as an intermediate that does not reduce further to with any significant rate. The mechanism of O 2 reduction to involves a first charge transfer step as rate‐controlling under Temkin conditions of adsorption.