The mechanism of corrosion inhibition of iron in acid solution by acetylenic alcohols

The mechanism of corrosion inhibition of iron by acetylenic alcohols in acid solutions was established by relating the interfacial structure obtained from spectroscopic measurements with the corrosion reaction kinetics obtained from electrochemical measurements. A modified adsorption interaction model was found to be applicable for describing the hydrogen evolution reaction on an inhibitor-covered iron electrode. For the iron dissolution reaction, a parallel dissolution model was found to be applicable. The parallel dissolution model was further justified by constructing the two-dimensional potential energy diagrams for iron dissolution on a free Fe surface and an inhibitor-covered surface with the use of Morse functions. A comprehensive analysis of the mechanism of corrosion inhibition in general is given. It is suggested that formation of a compact three-dimensional protective layer on the electrode surface is key for effective inhibition of corrosion.