Interactions between oxygen atoms on Pt(100): implications for ordering during chemisorption and catalysis.
We present a DFT analysis of the interactions between chemisorbed oxygen on the unreconstructed (1x1)-Pt(100) surface. These interactions control ordering of O not just for single-species adsorption, but also within O domains during coadsorption and reaction with other species such as CO. The calculations indicate that O prefers bridge sites, as deduced previously. In addition, we find a large difference in the interactions between O at different types of bridge site pairs separated by one lattice constant. There is strong repulsion for pairs separated by a Pt atom, but only a weak interaction for pairs separated by a fourfold hollow site. This finding elucidates the tendency for striped (nx1)-O ordering often observed in chemisorption and reaction studies.
Ames Laboratory-USDOE, Iowa State University, Ames, Iowa 50011, USA. dajiang@fi.ameslab.gov
Da-Jiang
DJ
Liu
James W
JW
Evans