Electrocatalytic Methanol Oxidation with Ni-B and Ni-P Electroless Modified Graphite Electrodes

In this article, the effect of the electrode surface morphology is investigated in the methanol electrooxidation process. For this purpose, a Ni-P layer of fine structure and two different Ni-B coatings having granular and cauliflower surface morphologies were plated separately on the graphite electrodes (GEs). The surface structure of samples was investigated by scanning electron microscopy (SEM) and their elemental analysis was done with electrode dispersive energy analysis (EDS). Then these modified electrodes were used as the anode for methanol oxidation reaction (MOR) in alkaline solution. Electrochemical studies were accomplished with cyclic voltammetry (CV) and chronoamperometry (CA) methods. Studies have shown, these different structures make a difference in the electrocatalytic performance of the electrodes and the highest methanol oxidation efficiency is related to Ni-B electrode with granular morphology. In order to reveal the methanol oxidation mechanism, coordination of anodic and cathodic peaks in CV diagrams was studied. Based on the results, we have offered the mechanism proposed by Fleischmann et al.