Nickel foam-based Ni(OH)(2)/NiOOH electrode as catalytic system for methanol oxidation in alkaline solution

摘要

The studies were focused on nickel foam-based Ni(OH)(2)/NiOOH electrodes concerned as active materials for methanol oxidation in alkaline solution. The properties of these electrodes were examined by cyclic voltammetry in 6 M KOH containing methanol. The results have shown that Ni(OH)(2)/NiOOH electrodes catalyze methanol oxidation through the mediation of Ni(III) ions generated on the electrode surface due to the Ni(OH)(2) --> NiOOH transformation. The electrode activity depends both on the intermediate step involving catalytic species of NiOOH as well as the concentration of CH3OH in the electrolyte. It was found, that passive layer formed on the electrode surface as result of methanol oxidation gives rise to a decrease of electrode activity. Electrochemical properties of Ni(OH)(2)/NiOOH electrodes are sensitive to oxidative modification, the effects of which influence the kinetics of methanol oxidation.