Correlations between the Kinetics of Electrolytic Dissolution and Deposition of Iron: II . The Cathodic Deposition of Iron

Abstract

The cathodic iron deposition reaction from acid solutions was studied. The partial current density‐potential curves of the iron deposition were calculated by current efficiency measurements. The experiments were carried out under steady‐state and nonsteady‐state conditions at 25°C under hydrogen atmosphere. Under steady‐state conditions a rotating gold disk electrode was used in order to eliminate the rise of pH in the vicinity of the electrode surface. The results show two different reaction mechanisms depending on the at the electrode surface. At the kinetic data correspond to a noncatalyzed mechanism, while at a catalyzed mechanism takes place. The influence of the surface on the mechanism is due to the différent electrochemical reaction orders related to the and the formation of hydrolysis products, which may be incorporated in the deposit. The calculated exchange current densities of the electrode show that the noncatalyzed mechanism is the normal one.