Regularities of cathodic hydrogen evolution at an electrolytic Co-V alloy and its components

摘要

The regularities of cathodic hydrogen evolution from a 30 % K.OH solution at an electrolytic Co-V alloy, an electrolytic cobalt coating as well as at cobalt and vanadium with smooth surface in the temperature range 25-85 °C have been studied. The Co-V alloy and cobalt coating were deposited on stainless steel from a nonaqueous electrolyte. It has been found that at the least negative potentials and with the lowest overpotential hydrogen evolves at the Co-V alloy. The exchange currents and real activation energies of hydrogen evolution at the investigated electrodes as well as the Tafel coefficients have been determined. On the basis of an analysis of the angular Tafel coefficient values, it has been shown that the rate of cathodic hydrogen evolution at cobalt and cobalt coating is controlled by the rate of formation of adsorbed hydrogen atoms while at vanadium and electrolytic Co-V alloy by the rate of their electrochemical desorp-tion.