Investigation of imidazole derivatives as corrosion inhibitors for mild steel in sulfuric acidic environment: experimental and theoretical studies

• Published in: Ionics Vol. 26; no. 10; pp. 5251 - 5272
• Main Authors: Ouakki, M., Galai, M., Rbaa, M., Abousalem, Ashraf S., Lakhrissi, B., Rifi, E. H., Cherkaoui, M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2020; Springer Nature B.V
• Subjects: Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Corrosion inhibitors; Electrochemistry; Energy Storage; Equivalent circuits; High resistance; Imidazole; Low carbon steels; Optical and Electronic Materials; Organic compounds; Original Paper; Phenols; Process parameters; Renewable and Green Energy; Sulfuric acid; Weight loss; Imidazole derivatives; DFT; Corrosion inhibition; SEM-EDAX; Molecular dynamic
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-020-03643-0

In this work, we are interested in studying the effect of the addition of three heterocyclic organic compound derived from imidazole, namely 2-(1,4,5-triphenyl-1H-imidazol-2-yl)phenol ( IM-OH ), 1,4,5-triphenyl-2-(4-metyoxyphenyl)-1H-imidazole ( IM-OCH 3 ), and 3-methoxy-4-(1,4,5-triphenyl-1H-imidazol-2-yl)phenol ( IM-H ) on the corrosion inhibition of mild steel in acidic medium H 2 SO 4 0.5 M. This study was performed using weight loss and electrochemical and theoretical investigations. The obtained results indicate that IM-OH , IM-OCH 3 , and IM-H act as excellent inhibitors for mild steel in H 2 SO 4 0.5 M. The results obtained from the electrochemical methods show that IM-OH, IM-OCH 3 , and IM-H imparted high resistance and behave as mixed type inhibitors. Inhibition efficiency (IE %) increases with the increase of inhibitors concentration to attain 97.7%, 98.9%, and 88.9% at 10 −3  M of IM-OH, IM-OCH 3 , and IM-H respectively. EIS data is analyzed to model the inhibition process through appropriate equivalent circuit model. Thermodynamic and kinetic parameters controlling the adsorption process are calculated and discussed. In addition, the surface of the mild steel has been analyzed by the SEM-EDAX. The theoretical results were in good agreement with experimental measurements.