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Influence of adsorbed Bi on the chemisorption properties of Pt(111): H/sub 2/, CO, and O/sub 2/
| Content Provider | United States Department of Energy Office of Scientific and Technical Information (OSTI.GOV) |
|---|---|
| Author | Paffett, M. T. Campbell, C. T. Taylor, T. N. |
| Organization | Los Alamos National Lab., NM (USA) |
| Abstract | The growth modes and interactions of vapor-deposited Bi on a clean Pt(111) surface and its effects on the chemisorption of H/sub 2/, CO, and O/sub 2/ have been monitored by Auger electron spectroscopy (AES), low-energy electron diffraction (LEED), and thermal desorption mass spectroscopy (TDMS). For submonolayer Bi coverages, LEED patterns were observed to progress with increasing coverage through p(2 x 2), (..sqrt..3 x ..sqrt..3)R30/sup 0/, p(3 x 3), and p(4 x 4) structures. The Bi TDMS and AES data are consistent with absolute coverages of 0.25, 0.33, 0.44, and 0.56, respectively. For submonolayer coverages of this s/sup 2/p/sup n/-type metal, Bi adatoms are strongly repulsive and maximize their spacing subject to the constraints of the Pt(111) sites. This is to be contrasted with d/sup n/s/sup m/-type metals such as Ag, Cu, and Au on Pt(111), which show attractive interactions and coalesce into 2d islands. In chemisorption of small molecules on Pt(111), each Bi adatom blocks about two Pt surface atoms. An ensemble of two adjacent Pt sites is required for both dissociative H/sub 2/ and molecular O/sub 2/ adsorption vs one site for CO adsorption; therefore, uptake of the former adsorbates is much more severely attenuated at theta/sub Bi/ increases. |
| Related Links | https://www.osti.gov/biblio/6215143 |
| Page Count | 19 |
| File Format | |
| Language | English |
| Publisher Date | 1984-01-01 |
| Publisher Place | United States |
| Access Restriction | Open |
| Subject Keyword | MATERIALS SCIENCE BISMUTH ADSORPTION CARBON MONOXIDE CHEMISORPTION HYDROGEN OXYGEN PLATINUM SORPTIVE PROPERTIES AUGER ELECTRON SPECTROSCOPY DEPOSITS DESORPTION ELECTRON DIFFRACTION CARBON COMPOUNDS CARBON OXIDES CHALCOGENIDES CHEMICAL REACTIONS COHERENT SCATTERING DIFFRACTION ELECTRON SPECTROSCOPY ELEMENTS METALS NONMETALS OXIDES OXYGEN COMPOUNDS PLATINUM METALS SCATTERING SEPARATION PROCESSES SORPTION SPECTROSCOPY SURFACE PROPERTIES TRANSITION ELEMENTS Metals & Alloys Physical Properties |
| Content Type | Text |
| Resource Type | Article |
