STRUCTURE OF ONE-ATOMIC-LAYER TITANIUM-OXIDE ON SILICON-OXIDE AND ITS PALLADIUM-MEDIATED RESTRUCTURING

The SiO2-attached one-atomic-layer titanium oxides (TiO2) were prepared by using the surface reaction between the OH groups of SiO2 and Ti(i-OC3H4)4 followed by calcination at 773 K. The one atomic layer TiO2 was characterized to have an anatase-like one-atomic-layer structure with (101) orientation by means of extended X-ray absorption fine structure spectra, X-ray diffraction, and X-ray fluorescence. The Pt or Pd supported on the one atomic layer TiO2 was also studied from chemical and structural interests. The amount of H-2 or CO adsorbed on these samples did not decrease with the reduction in H-2 at 773 K unlike the large suppression of the adsorption on Pt/TiO2 or Pd/TiO2 catalysts in the strong metal-support interaction state. The anatase structure of the one atomic layer TiO2 was maintained for the Pt-deposited sample, whereas the anatase structure was transformed to a rutile structure with (110) orientation keeping the one atomic layer structure for the Pd-deposited sample. The transformation from anatase to rutile structure could be mediated by interaction with Pd particles.