New 1H-pyrrole-2, 5-dione derivatives as efficient organic inhibitors of carbon steel corrosion in hydrochloric acid medium: Electrochemical, XPS and DFT studies. (January 2015)

• Record Type: Journal Article
• Authors: Zarrouk, A.; Hammouti, B.; Lakhlifi, T.; Traisnel, M.; Vezin, H.; Bentiss, F.
• Is Part Of: Corrosion science. Volume 90(2015)
• Page Start: 572
• Page End: 584
• Publication Date: 2015-01
• Subjects: A. Carbon steel -- A. Acid solutions -- B. XPS -- C. Acid inhibition; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2014.10.052
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: 1 H -pyrrole derivatives act as good corrosion inhibitors for carbon steel in 1 M HCl. Adsorption of the inhibitors on carbon steel surface obeys Langmuir's isotherm. XPS showed that the inhibitors are chemisorbed on the metal surface. Quantum chemical parameters were correlated with experimental results. Abstract: New 1 H -pyrrole-2, 5-dione derivatives, namely 1-phenyl-1 H -pyrrole-2, 5-dione (PPD) and 1-(4-methylphenyl)-1 H -pyrrole-2, 5-dione (MPPD) were synthesised and their inhibitive action against the corrosion of carbon steel in 1 M HCl solution were investigated at 308 K by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results showed that the investigated 1 H -pyrrole-2, 5-dione derivatives are good corrosion inhibitors for carbon steel in 1 M HCl medium, their inhibition efficiency increased with inhibitor concentration, and MPPD is slightly more effective than PPD. Potentiostatic polarization study showed that PPD and MPPD are mixed-type inhibitors in 1 M HCl. Impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. The results obtained from electrochemical and weight loss studies were in reasonable agreement. The adsorption of MPPD and PPD on steel surface obeyed Langmuir's adsorption isotherm. Thermodynamic data and XPS analysis clearly indicated that the adsorption mechanism of 1 H -pyrrole-2, 5-dione derivatives on carbon steel surface in 1 M HCl solution is mainly controlled by a chemisorption process. Quantum chemical calculations using the Density Functional Theory (DFT) were performed on 1 H -pyrrole-2, 5-dione derivatives to determine the relationship between molecular structures and their inhibition efficiencies.