Photo-assisted methanol oxidation on Pt-TiO2 catalysts for direct methanol fuel cells: A short review

Platinum and platinum-based electrocatalysts for the methanol oxidation reaction (MOR) are commonly used as the anode material in direct methanol fuel cells (DMFCs). Photo-oxidation promoted by ultraviolet and visible light is a promising method to increase the catalytic activity of DMFC anode electrocatalysts. Photocatalytic and electrocatalytic methanol oxidation can be coupled by addition of TiO2, a semiconductor photocatalyst, to Pt. In the presence of TiO2, an increase of the MOR activity of Pt-based electrocatalysts takes place also in dark conditions. This review deals with the methanol photo-oxidation on Pt/TiO2 catalysts, highlighting the effect of TiO2 morphology, nanoparticles, or 1D nanostructures, on the MOR activity under illumination. Comparison of reaction mechanisms in the presence and the absence of light are presented, and the roles of Pt and TiO2 during electrochemical and photochemical reactions are discussed.