Theoretical investigation of corrosion inhibition effect of imidazole and its derivatives on mild steel using cluster model

Interaction energies of imidazole and its seven derivatives on the surface of mild steel were calculated via a cluster model by using quantum chemical calculations at density functional theory level. The mild steel surface and its adsorption sites were considered as some clusters taken from two-layered (0 0 1) planes and the quantum chemical calculations which were carried out consist of adsorption of the inhibitor molecules on the surface of these clusters. It is shown that 90% of inhibition variations of the imidazole derivatives are described by considering perpendicular interaction of the inhibitors by iron atom in the mild steel unit cell.

► Extending DFT calculations to a new series of imidazole inhibitor compounds. ► Relating imidazoles interaction energies to inhibition efficiencies, successfully. ► Establishing an interpretable and effective model for inhibition efficiencies. ► Possibility of predicting new compound inhibition efficiency using the calculations. ► Reducing the number of experiment and the cost of testing corrosion efficiencies.