Preparation and characterization of Pt nanoparticles inside nanotubule TiO2.

Platinum nanoparticle has been supported on the tubular type titanium oxide using incipient wetness method employing H2PtCl6 as a precursor, where the loading was controlled to 4 wt%. The result of transmission electron micrographs of the sample showed the formation of Pt nanoparticles inside the tubule. The distribution of the particle size was found to be bimodal at ca. 1-2 nm and 5-6 nm, respectively. The former size was limited due to the inner diameter of the nanotubule. The particle size obtained from the hydrogen chemisorption, 1.24 H/Pt ratio was nearly 1 nm assuming spherical particle geometry, which was consistent with the formation of the Pt particle of 1-2 nm. The result suggested that there was no pore blockage for hydrogen since hydrogen can diffuse inside the channel through adsorption-diffusion-desorption on the Pt nanoparticle where the one dimensional channel was blocked with the particle itself.