Understanding Corrosion Inhibition of Mild Steel in Acid Medium by Some Furan Derivatives: A Comprehensive Overview

Abstract

The inhibition performance of some furan derivatives, namely, methyl 2-furoate, ethyl 2-furoate, and amyl 2-furoate on mild steel in normal hydrochloric acid medium (1 M HCl) at 25°C, was studied by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation measurements (EFM). Furan derivatives inhibit the acidic corrosion even at very low concentrations, reaching a value of inhibition efficiency up to 93% at a concentration of 20 mM. The results obtained from the different corrosion evaluation techniques are in good agreement. Polarization curves indicate that the studied furan derivatives are mixed-type inhibitors. Data obtained from EIS measurements were analyzed to model the corrosion inhibition process through an appropriate equivalent circuit model. A constant phase element has been used. The adsorption of furan derivatives on the steel surface in 1 M HCl solution was found to obey Langmuir's adsorption isotherm with a negative value of the free energy of adsorption Δ G̊ ads °. Molecular dynamics simulations were carried out to establish the inhibition mechanism. © 2010 The Electrochemical Society.