Dissolution of metals, its inhibition, and the Pearson principle. IV

The basics of the Pearson concept, i.e., the concept of hard and soft acids and bases (HSABs), were used to analyze the adsorptivity of chemical compo unds or ions on metals and some alloys, as well as their reactivity in the passivation process and in the initial stages of electrode depassivation in aqueous solutions. Although it is the presence of water in the corrosion e nvironment that usually plays the decisive role in the stability of metals and alloys, the theory and practice of corrosion protection also deal with more complex systems than the classical system metal-aqueous electrolyte. T he most important of these systems are formed during the atmospheric corros ion of metals, which arises not only under "thick," i.e., phase water films , but also under adsorption aqueous films [2-5].