Preparation and characterization of Pt/TiO2 nanotubes catalyst for methanol electro-oxidation

Titanium dioxide nanotubes were prepared via a hydrothermal treatment of TiO2 powder (Degussa P25). Obtained samples were analyzed by various techniques, such as transmission electron microscopy (TEM) and X-ray diffraction (XRD), which revealed that the crystal structure of the obtained materials was similar to that of H2Ti2O5·H2O nanotubes, and were about 50 nm in length and 20 nm in diameter. Nitrogen adsorption–desorption isotherms indicated that synthesized solids are mesoporous materials with a multi-walled nanotubular structure and high specific surface area. The methanol oxidation reaction was investigated on platinum nanoparticles supported TiO2 nanotubes (XC72). The electrocatalytic activity of the catalyst was measured by cyclic voltammetry. CO stripping voltammetry in acidic solutions was investigated to study the reaction of the catalysts towards poisoning by carbonyl compounds. The results demonstrated that Pt/TiO2 nanotubes catalyst exhibits the best activity for methanol oxidation and were favorable for improving the tolerance to poisoning species.

TEM images of Pt/TiO2 nanotubes catalyst which clearly demonstrate a typical structure of nanotubes and uniform platinum particles well dispersed on titanium dioxide nanotubes.Figure optionsDownload as PowerPoint slideHighlights
• Studies of adsorption isotherms showed the presence of TiO2 nanotubes higher specific surface area which is preferable for the electro-catalyst.
• The TEM and the XRD proved that TiO2 nanotubes exhibit uniform distribution in length and diameter.
• The TGA–DTA results illustrated that the amount of H2O contained in the TiO2 nanotubes was higher than that of TiO2.
• Pt/TiO2 nanotubes/C catalyst exhibits the best activity for methanol oxidation and was favorable for improving the tolerance to poisoning species in comparison with Pt/TiO2 (Degussa P25) and Pt/C (XC72) electrocatalysts.