AVS 49th International Symposium
    Surface Science Tuesday Sessions
       Session SS3-TuM

Paper SS3-TuM5
STM Studies of Titanium Oxide Adlayers on a Pt(100) Surface

Tuesday, November 5, 2002, 9:40 am, Room C-112C

Session: Metals, Adsorbates, and Defects on TiO@sub 2@
Presenter: T. Matsumoto, University of Southern California
Authors: T. Matsumoto, University of Southern California
M. Batzill, Tulane University
S. Hsieh, University of Southern California
B.E. Koel, University of Southern California
Correspondent: Click to Email
Pt supported on titanium oxide catalysts exhibit effects termed SMSI (strong metal support interaction). In order to probe aspects of this chemistry, thin films of titanium oxide on Pt single crystal surfaces have been observed by using surface science techniques, but most studies focused on titanium oxide films that fully covered the surface. In this study, submonolayer coverages and ultrathin films of titanium oxide on Pt(100) were observed by STM, LEED and XPS, and we report several new, ordered structures. These titanium oxide structures were produced by annealing to 800-1300 K after the deposition of Ti in an oxygen atmosphere or additional oxidation with NO@sub 2@ and O@sub 3@ after Ti deposition. A (3×5) structure of Ti@sub 2@O@sub 3@ was found after annealing above 800 K. This structure could also be produced by O@sub 3@ oxidation of the Pt@sub 3@Ti surface alloy produced on Pt(100). Our proposed structural model suggests that the thin film of titanium oxide with the (3×5) structure covers the Pt(100) surface fully. Several other locally ordered structures were found by annealing below 1000 K after additional oxidation of the (3×5) structure with NO@sub 2@ and O@sub 3@. These were more oxidized than Ti@sub 2@O@sub 3@, and were changed to the (3×5) structure after annealing to 1000 K.