Development of Nickel Oxide and Manganese Oxide Nanostructured Binary Modified Anodes for Methanol Electro-Oxidation

摘要

In this investigation, a nanoparticle-based binary catalyst composed of nickel oxide (nano-NiOx) andmanganese oxide (nano-MnOx), both were assembled on a platinum substrate, was developed for thedirect methanol electro-oxidation (MO) in an alkaline medium. The morphological investigation wasperformed using field-emission SEM and revealed the electrodeposition of MnOx in a nanorodstructure and NiOx in round-shaped nanospheres. The electrocatalytic activity of the modifiedelectrodes towards MO depended critically on the order of deposition of the two oxides. The optimumelectrocatalytic activity was obtained at the MnOx/NiOx/Pt electrode (in which nano-NiOx was directlyelectrodeposited 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 ofmethanol and the charge transfer during MO.