Accession Number : ADA140569

Title :   Thin Film Models of SMSI (Show Strong Metal-Support Interactions) Catalysts: Pt on Oxidized Titanium.

Descriptive Note : Technical rept. 1 Jan-31 Dec 83,


Personal Author(s) : Beltyon,D N ; Sun,Y M ; White,J M

PDF Url : ADA140569

Report Date : 17 Oct 1983

Pagination or Media Count : 29

Abstract : Thin films of Pt, vapor deposited on an oxidized Ti foil, have been utilized as models of high surface area Pt/TiO2 catalysts which show strong metal-support interactions (SMSI). Both fully oxidized (Ti(4+)) and partially reduced (significant amounts of Ti(3+)) surfaces were studied. As a function of Pt coverage, the development of bulk Pt chemisorption characteristics occurs at significantly lower coverages on the oxidized substrate. In particular, at a given Pt coverage there is less chemisorption of both CO and H2 on the reduced, a compared to the oxidized, TiO2 and the desorption spectra peak at lower temperatures. No evidence for significant differences in the chemical state of the Pt is found by XPS and AES. We propose a model, consistent with earlier work on high surface area Pt/TiO2 catalysts, in which the morphology of the Pt on the reduced catalysts is significantly flatter (dominated by (111) terraces) and is slightly modified electronically, as compared to the oxidized sample.

Descriptors :   *Thin films, *Platinum, *Vapor deposition, *Titanium, *Catalysts, Foils(Materials), Interactions, Surface chemistry, Chemisorption, Titanium oxides, Substrates, Carbon monoxide, Hydrogen, Desorption, Spectra, Morphology, Models, X ray photoelectron spectroscopy, Auger electron spectroscopy, Oxidation, Reduction(Chemistry)

Subject Categories : Inorganic Chemistry
      Atomic and Molecular Physics and Spectroscopy
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE