SYNTHESIS AND CHARACTERIZATION OF SOL-GEL PT TIO2 CATALYST/

Pt/TiO2 catalysts with 1.0 wt% Pt were prepared by using the sol-gel t echnique with Ti(OBut)(4) and platinum acetylacetonate. The catalysts were prepared in only one step, without the need to reduce the sample in hydrogen. All fresh samples have three nanophases: rutile (the majo rity phase), anatase, and platinum. Their crystalline structure was ob tained by X-ray powder diffraction and refined with the Rietveld techn ique. Samples were also characterized by FTIR spectroscopy. Platinum p romoted the formation of rutile. This could stem from either the prese nce of PtO2, which has the rutile structure, as an intermediate phase, or the platinum-catalyzed dehydroxylation of anatase. Although PtO2 a nd rutile have the same crystalline structure, platinum atoms did not go into the crystalline structure of rutile. (C) 1996 Academic Press, Inc.