Investigation of Reserpine as a Corrosion Inhibitor for Carbon Steel and Aluminum in Acetic/Acetate Medium Used for De-Icing Applications

This study investigates the efficacy of Reserpine (RZ), a natural indole alkaloid, that serves as a sustainable inhibitor of corrosion for OLC52 and aluminum in a 0.5/0.25 mol L−1 acetic acid/potassium acetate solution, relevant to de-icing applications. The electrochemical methods used in this study included cyclic (CV) and linear sweep voltammetry (LSV), chronoamperometry (CA) and electrochemical impedance spectroscopy analysis (EIS), and allowed for the determination of the necessary parameters for the evaluation of the adsorption behavior. In addition to electrochemical studies, theoretical molecular modeling calculations were also carried out. The results indicate that RZ reduces the corrosion rate at the highest tested concentration of 10−3 M RZ, reaching inhibitory efficiencies of 90% for OLC52 and 94% for Al. The adsorption aspects have been described by the Langmuir and Freundlich isotherms, whose ∆Gadso resulting values suggest a physicochemical adsorption by forming a compact and protective layer. Molecular modeling demonstrates RZ’s ability to interact with metal surfaces taken into action through both donor–acceptor and electrostatic interactions, highlighting the potential of RZ as a green corrosion inhibitor in similar environments, usable in de-icing solution formulations.