Molecular dynamics, DFT and electrochemical to study the interfacial adsorption behavior of new imidazo[4,5-b] pyridine derivative as corrosion inhibitor in acid medium

摘要

The present paper discusses the adsorption and inhibitory effect of a new pyridine derivative, namely, 6-bromo-2-(4-methoxyphenyl)-3-nonyl-3H-imidazo[4,5-b] pyridine (PIP) on mild steel corrosion in molar hydrochloric acid medium. The experimental study was carried out using a series of techniques such as weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The effectiveness of this compound reaches a maximum value of 92% at 10(-4) M. The obtained results showed that the adsorption process on the metal surface follows the Flory-Huggins adsorption model. Scanning electron microscopy (SEM) confirmed the existence of an adsorption film on the MS. The relationship between the corrosion inhibition efficiency and the molecular electronic properties of the studied compound were performed using Quantum chemistry method at the level of DFT/B3LYP at 6-31G (d,p) basis set. Quantum chemical calculations indicated that the investigated molecule has a tendency to be protonated in the acid medium. Molecular dynamics (MD) simulations were performed to evaluate the reactivity (interactions) of the system Fe (110) surface/PIP in HCl. A very good agreement was recorded with the experimental data.