Preparation of noble metal supported carbon electrodes using photochemically reduced heteropolyanions in composite films

Abstract

A novel reduction technique is developed for preparing a Pt/C system using organic–inorganic nanocomposite consisting of heteropolyanions. Transmission electron microscopic studies revealed the formation of anisotropic platinum nanocrystals. Cyclic voltammetry and electrochemical impedance spectroscopy were employed to evaluate the electrochemical methanol oxidation over the prepared Pt/C electrode. The effects of supporting electrolyte and temperature on the electrochemical oxidation of methanol were studied. The obtained Pt/C catalysts were found to exhibit higher activity and stability for methanol oxidation in perchloric acid than in sulphuric acid medium. The activation energy for methanol oxidation was found to be 41 ± 3 kJ mol−1 , being lower than the reported value. The lower activation energy for methanol oxidation on Pt/C could be attributed to the presence of anisotropic platinum nanoparticles. The described method is simple and elegant and can also be applied to the preparation of other noble metal supported catalysts.