Investigation of Hydrogen Evolution Reaction on (TiCr1.8)xV100 – x Alloys via Impedance Spectroscopy Method

The behavior of the (TiCr1.8)xV100 – x intermetallic system in the reaction of hydrogen evolution in 1 M KOH solution has been studied by polarization measurements and electrochemical impedance spectroscopy. Cathodic polarization curves and impedance spectra were obtained in the potential range corresponding to the linear region of the log i–E dependence. All investigated alloys have two linear sections on the cathodic polarization curves. The two sections of the potential dependence are also revealed in other electrochemical parameters of the system. Impedance spectroscopy allowed establishing that no thick oxide film is present on the alloys’ surfaces. For the analysis of the obtained impedance spectra, three equivalent electrical circuits were applied, in order to describe the electrochemical hydrogen evolution. The parameters of the Faraday impedance were calculated. Assumptions about the hydrogen evolution reaction behavior according to the Volmer–Heyrovsky mechanism and Temkin adsorption isotherm were made.