Theoretical Prediction and Experimental Study of Benzimidazole Derivate as a Novel Corrosion Inhibitor for Carbon Steel in 1.0 M HCl

The inhibiting effect of benzimidazole derivate (DBI) on corrosion of carbon steel (CS) at temperature range of 303–333 K was investigated in hydrochloric acid by DC potential dynamic polarization and AC electrochemical impedance spectroscopy. It was found that this compound behaved as a mixed-type inhibitor with predominantly cathodic effect. The EIS results indicate that the inhibition efficiency increases with increasing the inhibitor concentration and the maximum inhibition (%) was obtained in the presence of 10−3 M of DBI. The adsorption of DBI on the carbon steel surface is described by the Langmuir adsorption isotherm and had a physical and chemical mechanism. The results found experimentally were corroborated by DFT-quantum chemical calculations and molecular dynamics simulations (MDS) methods.