The Mechanism of Oxygen Reduction on Iron in Neutral Solutions

Abstract
The pathways and rate‐determining steps of oxygen reduction on iron in neutral pH range have been investigated. The various mechanistic criteria are obtained as a function of the nature of the electrode surface: bare iron and passive iron. The oxygen reduction on bare iron proceeds through 4e pathways with little hydrogen peroxide as an intermediate and formation of superoxide radical in the rds. On passive iron, oxygen reduction proceeds through a 2e pathway with the formation of hydrogen peroxide as a reaction product. An rds involving chemisorption of oxygen is suggested.