Development of nickel oxide and manganese oxide nanostructured binary modified anodes for methanol electro-oxidation

Abstract

In this investigation, a nanoparticle-based binary catalyst composed of nickel oxide (nano-NiOx) and manganese oxide (nano-MnOx), both were assembled on a platinum substrate, was developed for the direct methanol electro-oxidation (MO) in an alkaline medium. The morphological investigation was performed using field-emission SEM and revealed the electrodeposition of MnOx in a nanorod structure and NiOx in round-shaped nanospheres. The electrocatalytic activity of the modified electrodes towards MO depended critically on the order of deposition of the two oxides. The optimum electrocatalytic activity was obtained at the MnOx/NiOx/Pt electrode (in which nano-NiOx was directly electrodeposited onto the Pt surface followed by nano-MnOx) with a total surface coverage of ca. 86%. Both nano-NiOx and nano-MnOx are believed to act as catalytic mediators facilitating the adsorption of methanol and the charge transfer during MO. © 2014 The Authors.