Nanostructured NiTiO₃ as a catalytic material for methanol electrochemical oxidation in alkaline conditions

The electro-catalytic activity of nanostructured nickel titanate (NiTiO3) powders synthesized by a Sol-Gel process was evaluated by means of the electro-oxidation of methanol in alkaline media. In order to correlate the structural, vibrational, morphological and optical properties of the NiTiO₃ powders with their electrochemical activity they were characterized by X-ray diffraction (XRD), Raman spectroscopy, Transmission Electron Microscopy (TEM) and Diffuse Reflectance Spectroscopy (DRS). The powders are formed by nanoparticles of the order of 25 nm. It is shown that the electro-oxidation of methanol in alkaline media is possible in the presence of nanoparticles of this non-noble metal compound, as demonstrated by the current-versus-potential characteristics obtained as a function of methanol concentration. It is shown that the activated Ni atoms at the NiTiO₃ nanoparticles cause a great increase of the electro-oxidation rate of methanol under alkaline conditions. Therefore, this opens the possibility that a layer of nanostructured NiTiO₃ might be used as a catalyst for direct alkaline methanol fuel cells.