High dispersion and electrocatalytic activity of Pd/titanium dioxide nanotubes catalysts for hydrazine oxidation

Pd/titanium dioxide nanotubes (Pd/TiO2-NTs) catalysts were prepared by a simple reduction method using TiO2-NTs as support. The structure and morphology of the resulting Pd/TiO2-NTs were characterized by transmission electron microscopy and X-ray diffraction. The results showed that Pd nanoparticles with a size range from 6 to 13 nm were well-dispersed on the surface of TiO2-NTs. The electrocatalytic properties of Pd/TiO2-NTs catalysts for hydrazine oxidation were also investigated by cyclic voltammetry. Compared to that of pure Pd particles and Pd/TiO2 particles, Pd/TiO2-NTs catalyst showed much higher electrochemical activity. This may be attributed to the uniform dispersion of Pd nanoparticles on TiO2-NTs, smaller particle size and unique properties of TiO2-NTs support. In addition, the mechanism of hydrazine electrochemical oxidation catalyzed by Pd/TiO2-NTs are also investigated. The oxidation of hydrazine was an irreversible process, which might be controlled by diffusion process of hydrazine.