Article ID Journal Published Year Pages File Type
9594917 Surface Science 2005 16 Pages PDF
Abstract
Approximate molecular orbital calculations have been applied to explain the low CO poisoning effects observed at PtBi2 and PtBi electrodes. The bonding patterns for chemisorption of CO on the surfaces of Pt-Bi bulk alloys and pure Pt surfaces are quite similar. The major difference is not induced through much Pt-Bi bonding, but indirectly, by raising the Fermi level of the system, so that the C-O π* levels become practically filled upon interaction. This results in much lower adsorption energies than in the metallic Pt case, in accordance with experimental data. The calculations also imply C-O bond dissociation on the surface, a phenomenon not supported by experiment. CO adsorption at Pt-Pt bridge site (possible only on PtBi) is favored relative to atop chemisorption.
Related Topics
Physical Sciences and Engineering Chemistry Physical and Theoretical Chemistry
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