Development of a BV-TDDFT model for metal corrosion in aqueous solution

Abstract

Metal corrosion is a widespread process that has a significant influence in many fields. Traditional electrochemical methods poorly approximate the interfacial effect, which plays an important role in metal corrosion. We propose a novel reaction–diffusion model by combining the Butler–Volmer (BV) equation and classical time-dependent density functional theory (TDDFT). This new model was used to investigate both the interfacial effect and molecular correlations and was applied to fit and predict the corrosion process for carbon steels, Zn, Ni, Mg, and Al. The predicted polarization curve agreed well with the experimental results, and the density profiles indicated the significance of the interfacial effect. The effects of temperature, diffusion layer, and pH on corrosion were also examined, and the BV-TDDFT model provided reasonable predictions. Additionally, we observed a linear correlation between the reaction rate constant and anion concentration, and proposed a semi-empirical method to predict metal corrosion at different ionic strengths.