New chlorophenyl-imidazole derivative as a novel corrosion inhibitor in the gas and oil industry

Abstract

We report herein the synthesis of (E)-3-[2-(4-chlorophenyl)imidazo[1,2-a]pyridin-3-yl]-1-mesitylprop-2-en-1-one (IMCH) as a new chlorophenyl-imidazole derivative that serves as an effective corrosion inhibitor for mild steel (MS) in 1 m HCl solution. IMCH bears additional electron donor groups and functional groups compared to previous inhibitors. Its chalcone structure has been confirmed by IR spectroscopy, 1H and 13C NMR spectrometry, and mass spectrometry. The corrosion inhibition efficiency of IMCH has been investigated by surface morphology (SEM and AFM) inspection, electrochemistry (EIS and PDP), and gravimetric, theoretical (DFT), and computational (Monte Carlo simulation) studies. It was found that the maximum protection of IMCH was 87.59% at a 1 mm loading. The adsorption of IMCH on a metal surface has been demonstrated using the Langmuir isotherm model, and its adsorption free energy has been evaluated as ΔGads = −35.35 kJ/mol, indicating that the process is spontaneous and occurs through chemisorption and physisorption. The combination of a chlorine atom, an aromatic ring, and an imidazole moiety is mainly responsible for enhancing the corrosion inhibition of IMCH. DFT and MCS results have confirmed that the polarization, adsorption positions, π-system, and heteroatoms are key parameters in enhancing of corrosion efficiency of IMCH.