Assessment of the inhibition of carbon steel corrosion by an imidazole derivative in 1 M HCl: Experimental and theoretical approaches

Abstract

This investigation examines the application of 2, 4,5-tris(2-methoxyphenyl)-4,5-dihydro-1H-imidazole (2M-C), a recently synthesized, ecologically benign imidazole derivative in terms of corrosion inhibitor for carbon-steel (C-Stl) in a 1 M HCl acid solution. The findings of this study could lead to significant advancements in the field of corrosion inhibition. The chemical and electrochemical methods used to evaluate the effectiveness of the 2M-C molecule were weight loss (WL), potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). Quantum chemical analyses were also conducted. The results revealed excellent anticorrosion properties, with maximum inhibition efficiency (IE%) reaching 98.6 % at a concentration of 10⁻³ M. PDP analyses indicate that 2M-C acts as a mixed/inhibitor. The effects of temperature on the inhibition process suggested chemical adsorption of 2M-C onto the carbon-steel/surface, apparently following the Langmuir-adsorption model. Analyses by Scanning Electron Microscopy (SEM) coupled to Energy Dispersive X-ray (EDX) & UV–visible spectroscopy confirmed the formation of a protective film that restricts the access of corrosive ions to the metal surface. Moreover, alongside the experimental findings, theoretical investigations employing Density Functional Theory (DFT) and Molecular Dynamics (MD) can elucidate the reactive sites of the molecule and enhance comprehension of the adsorption process.