AVS 46th International Symposium
    Surface Science Division Monday Sessions
       Session SS2-MoA

Invited Paper SS2-MoA1
Surface Chemistry on Stepped Pt Surfaces - What Happens at the Steps?

Monday, October 25, 1999, 2:00 pm, Room 607

Session: Reactions on Metals
Presenter: J.T. Yates, Jr., University of Pittsburgh
Authors: J.T. Yates, Jr., University of Pittsburgh
C.E. Tripa, University of Pittsburgh
T.S. Zubkov, University of Pittsburgh
M. Mavrikakis, Technical University of Denmark
J.K. Norskov, Technical University of Denmark
Correspondent: Click to Email
H.S. Taylor postulated in 1925 that step sites on metallic surfaces are active sites for catalytic reactions. This postulate has become one focus of surface science research since the 1970's. We have studied both photochemical processes and thermally driven processes which occur specifically at metallic step sites. The photodecomposition of adsorbed O@sub 2@ on Pt(335) and Pt(779) surfaces has been used to study the reaction of photogenerated O atoms with CO molecules on both step and terrace sites producing CO@sub 2@. A surface-aligned photochemical process is observed. In addition, the chemisorption of N@sub 2@ on the step sites of these two crystals has been investigated by infrared spectroscopy and by kinetic methods. Linear arrays of weakly-based N@sub 2@ molecules have been observed and their properties will be described. N@sub 2@ does not adsorb on the (111) terrace sites separating the steps.