Electrocatalytic oxidation of methanol on Ru deposited NiZn catalystat graphite in alkaline medium

Abstract

The methanol oxidation on C/NiZn-Ru electrode in a 1.00 M KOH and 1.00 M KOH + 1.00 M methanolsolutions at different scan rates and temperatures was studied by the cyclic voltammetry (CV), electro-chemical impedance spectroscopy (EIS) and chronoamperometry (CA) techniques. The graphite electrodeis coated in a nickel–zinc bath by electrodeposition for use as anode materials for methanol oxidationin alkaline solutions. It is etched in a concentrated alkaline solution to produce a porous and electrocat-alytic surface suitable for use in the methanol oxidation (C/NiZn). Ruthenium was electrodeposited on aC/NiZn electrode. The surface morphologies and compositions of electrodes were determined by energydispersive X-ray (EDX) and scanning electron microscopy (SEM). Kinetic parameters of oxidation suchas the anodic electron transfer coefficient (˛a), cathodic electron transfer coefficient (˛c), charge transferrate constant (ks) and activation energy values were calculated. The effect of methanol concentration onmethanol oxidation were also investigated. It was found that the ruthenium electrodeposited electrodeshowed higher catalytic activity and stability toward methanol oxidation than the C/NiZn electrode.