Electrochemical and Quantum Chemical Studies of Aromatic Amines on the Steel Corrosion in Acid Solution

Abstract

The corrosion inhibitor efficiency of aromatic amines for mild steel in 0.5 M sulfuric acid (H2SO4) was investigated using polarization and weight-loss measurements. The results revealed that these inhibitors exhibit good corrosion inhibition even at a very low concentration. Polarization curves showed that all of the compounds are mixed-type inhibitors. The adsorption of inhibitors is found to obey the Langmuir isotherm. Molecular parameters that are directly related to the corrosion inhibition properties of any compound are investigated using the density functional theory (DFT) quantum chemical method. These results show that the electron pair on oxygen atoms of the nitro group are the preferred site for adsorption of these compounds on an iron surface.