Investigation of methanol oxidation on nickel-cobalt coated copper electrode

In this study, NiZn coating was made on a copper surface with electrochemical technique. After active zinc removal in NaOH solution, Co was deposited on Ni(Zn) surface and CuNi(Zn)Co electrode was prepared for methanol oxidation. Deposition current density and deposition time were investigated and optimun conditions were determined for the methanol oxidation. It was found that, the methanol oxidation activity of coatings depends on the metal ratio, deposition current density and the deposition time of coatings. The catalytic effect of prepared electrodes for the methanol oxidation was studied in 1,00 M Methanol solution containing 1,00 M KOH by cyclic voltammetry, chronoamperometry, chronopotentiometry, electrochemical impedance spectroscopy techniques and current-potential curves. The surface morphology and chemical composition of electrodes are determined by using scanning electron microscopy (SEM), atomic force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDX) The alkaline leached Ni(Zn)Co coating as well as good electrocatalytic activity for the methanol oxidation in alkaline media. The results obtained show that methanol oxidation was increasing Cu, Co, Ni, NiZn, Ni(Zn)Co, respectively. The activattion energy of CuNi(Zn)Co (6559,3 J cm-2) for the oxidation of methanol is less than the other electrodes (CuNi:32657 J cm-2, CuNi(Zn): 6749,3 J cm-2). The results of chronoamperometry shows that the loss activity for NiZn electrode and CuNi(Zn)Co electrodes were 2.7% and 1.7%. The catalytic activity and stability of the modified electrode that was preapared was higher for the oxidation of methanol.