Electrochemical behavior of aluminum alloy AA2024 in aqueous solutions in the presence of caffeine

The influence of the presence of caffeine (CFN) on the electrochemical behavior of aluminum alloy AA2024 in aqueous solutions was studied. The interaction between the metal surface and the organic compound is potential dependent as well as time dependent. The anodic currents, responsible for the metal dissolution, decreases in the presence of caffeine even adding chloride anion as contaminant. The EIS data obtained at the open-circuit potential clearly demonstrated that the adsorption of CFN on the surface of the AA 2024 electrode is favored allowing the film defects to be repaired. The protective action of CFN is considerably improved on increasing the adsorption time due to a sealing process which enhances the film stability.