Kinetics of Electrode Processes on Metals Coated with Hydrocarbon Films in Solutions of Electrolytes

Abstract

Kinetics regularities of hydrogen evolution reaction (HER) on Armco iron and copper anodic ionization, covered with a hydrocarbon film based on I-20A oil with a fixed amount of gun grease of the highest quality (GGHQ), were studied at room temperature. The measurements were carried out in aqueous and methanol solutions with the electrolyte composition of x M HCl + (1 x) M LiCl and 0.1 М HCl + х М LiCl + (3.9 х) М LiClO4. The Tafel slope coefficients values, and the orders of reactions, with respect to hydrogen ions (Fe, Cu) and chloride-ions (Cu) were estimated. The effect of oxyethylated amines (OEA), introduced into the solution or hydrocarbon surface coating, on the kinetics of electrode processes, for iron and copper, has been studied. It is shown that HER mechanism on Armco iron and copper anodic ionization does not change in the presence of a hydrocarbon coating on the metal surface. Large OEA molecules freely penetrate from the solution through the hydrocarbon coating to the metal surface, changing partial electrode reactions kinetics. The results are interpreted taking into account the hydrocarbon films surface porous structure.