Further Studies on the Anodic Corrosion of Lead in H[sub 2]SO[sub 4] Solutions

Anodic corrosion of lead in sulfuric acid was studied in detail at potentials near the reversible potential. Results indicate that the first step in the corrosion process was reaction of lead with water to form lead dioxide. The solid‐phase reaction probably occurred below a certain potential, and this reaction plus two electrochemical reactions rendered lead dioxide unstable at lower potentials. A potential was found at which the corrosion rate reached a sharp peak. Above this peak lead dioxide was found in the reaction product. Kinetic treatment was only partially successful. In 30% acid, at potentials just below the reversible potential, conversion of lead dioxide film to lead sulfate took place, and the rate of corrosion appeared to be controlled by diffusion of the electrolyte into the film. Above the reversible potential, a protective lead dioxide film was formed, and a linear rate of corrosion was found which increased with increasing temperature and decreasing acid concentration.