Inhibition of acid corrosion in API 5L X52 steel with 1,2,3-triazole derivatized from benzyl alcohol: Experimental and theoretical studies

Abstract

This work presents the synthesis of new triazoles derived from benzyl alcohol to be used as corrosion inhibitors for API 5L X52 steel in HCl 1M medium. The results showed that all derivatives displayed a better inhibitory capacity than benzyl alcohol. Electrochemical impedance spectroscopy in conjunction with polarization curves revealed that compound 6 showed the highest inhibitory capacity of all derivatives with 94.2% inhibition efficiency at a concentration of 50 ppm. Furthermore, it was determined that compounds 3, 6 and 7 were inhibitors with anodic behavior and compounds 4 and 5 acted as mixed inhibitors. Benzyl alcohol and all its synthesized derivatives fitted the Langmuir adsorption isotherm. The combined adsorption phenomenon was proposed according to the thermodynamic parameter values obtained. Dispersion-corrected DFT studies, assuming the cluster approach, obtained free binding energies that matched well with experimentally determined standard adsorption free energies. The mixed physisorption-chemisorption observed was explained in terms of the electrostatic interactions and chemical bonding between the metal surface and the corrosion inhibitor. Finally, compound 6 obtained the largest charge transference to the metal cluster.