Technical Note: Mechanism of Corrosion of Iron by Hydrochloric Acid and Its Inhibition by Iodide and Quinoline^☆ Available to Purchase

The kinetics and mechanism of iron dissolution in acids have been the subject of numerous investigations and these are quoted by Hilbert, et al.¹  The great number of experimental results led mainly to two theories about the anodic dissolution mechanism of pure iron worked out by Heusler,²  Bockris,³  and Kelly.⁴  Both theories indicate participation by hydroxyl ions in the dissolution process in H₂SO₄ solution. The generation of OH⁻ ions in H₂SO₄ solution is presumed to occur by dissociation of water molecules at the electrode surface. The effect of anions on the kinetics of metallic dissolution has been reviewed by Kolotyrkin.⁵  While SO₄⁻⁻ and ClO₄⁻ are not surface active and, therefore, do not participate in the dissolution process. Chloride ions appear to influence the dissolution process, and hence its participation has been taken into account...