ICOHPs as a More Reliable Indicator than Adsorption Energies to Predict Corrosive Effects: A Density Functional Theory Investigation Into Degradation of Alumina by Chlorine‐Containing Corroders

ABSTRACT Although an excellent corrosion inhibitor, alumina deteriorates in the presence of chlorine. This systematic study probes how the most common chlorine‐containing corroders, namely , HCl, NaCl, KCl, , and interact with an ‐ (0001) surface. Using a host of density functional theory‐computed parameters, including adsorption energies, integrated crystal orbital Hamilton population (ICOHPs), combined with ab initio molecular dynamics studies, the adsorption of the corrosive species and their stability on the inhibitor surface is probed in great depth. Adsorption energies indicate that a higher ionic character of the corroder leads to a stronger adsorption on the alumina surface. However, ICOHP analyses of various bond pairs indicate that HCl, with a lower adsorption energy is more detrimental to the inhibitor slab in line with experimental observations. Overall, the study shows that ICOHPs are a more reliable predictor of corrosive effects than adsorption energies.