Document Type : Original Article
Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
A new nanocatalyst was prepared using montmorillonite (MMT) clay mineral as a low-cost substrate incorporation with platinum and osmium nanoparticles for electrocatalytic oxidation of methanol molecules. The morphology and microscopic structure of the nanocomposite film formed at the surface of the fluorine tin oxide (FTO) electrode, were characterized by scanning electron microscopy and energy dispersive X-ray analysis. The electrocatalytic activity of the Pt-Os/Clay/FTO modified electrode was compared with Pt/FTO and Pt/Clay/FTO electrodes using cyclic voltammetry and chronoamperometry techniques and it was found that the Pt-Os/Clay/FTO electrode has a better performance for oxidation of methanol molecules. The exchange current density (J0) values for Pt/FTO, Pt/Clay/FTO and Pt-Os/Clay/FTO were calculated using the Tafel equation and they were found to be: 2.48×10-6, 4.01×10-6 and 8.45×10-6 mA cm-2, respectively. The results indicate that the purposed electrode accelerates significantly the process of methanol electrooxidation. The effects of various parameters on the electro-oxidation of methanol molecules were investigated and the obtained experimental results were discussed. The new modified electrode, showed a significant electrocatalytic activity for methanol electrooxidation over the other Pt-modified electrodes.