Corrosion inhibition properties of 1,2,4-Hetrocyclic Systems: Electrochemical, theoretical and Monte Carlo simulation studies

摘要

Inhibition of mild steel corrosion in 1N hydrochloric acid with 4-amino-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one (AMTDT) and (4-amino-4H-1,2,4-triazole-3,5-diyl) dimethanol (ATD) was investigated by polarization (Tafel), electrochemical impedance (EIS), adsorption and computational calculations at 27°C. The mixed type inhibitor property of these inhibitor molecules was investigated by potentiodynamic polarization studies. It was revealed that the effectiveness of inhibition is influenced by several factors such as the nature and state of the metal surface, the type of corrosive medium, the structure of the chemical compound used as inhibitor and molecular electronic parameters. Obvious correlations were found between corrosion inhibition efficiency and some quantum chemical parameters. Monte Carlo simulations were applied to search for the most stable configuration and adsorption energy for the interaction of inhibitors on Fe (111) interface. Calculated results indicated that the difference in inhibition efficiencies between the compounds can be clearly explained in terms of frontier molecular orbital theory.