Influence of Cr content in Fe/Cr alloys on the adsorption behaviour of Cl− ion in pH=2 acid solution

Purpose The paper aims to investigate the effect of Cr content on Cl− adsorption behaviour. Design/methodology/approach The adsorption behaviour of Cl− on Fe-xCr (x = 10, 20, 30, 50, 75 At.%) alloys in HCl + NaCl solution (pH = 2, [Cl−] = 0.1 M) has been studied by electrochemical techniques, X-ray photoelectron spectroscopy and first-principle calculations. Findings The results show that both the adsorption energy and distance decreased with increasing Cr content, which shows the adsorption of Cl− is dependent on the amount of Cr present. Cr oxides of the passive films on Fe50Cr and Fe75Cr alloys inhibited the adsorption of Cl−. Originality/value Investigation of the relationship between the Cr content and the role of Cl− adsorption provides a reliable basis for the design of corrosion-resistant alloys.