Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5424019 | Surface Science | 2009 | 7 Pages |
Abstract
The adsorption of CO on Pt(1 1 1), (2 Ã 2) and (â3 Ã â3)R30° Sn/Pt(1 1 1) surface alloys has been studied using temperature programmed desorption (TPD), low energy electron diffraction (LEED) and infrared reflection adsorption spectroscopy (IRAS). The presence of Sn in the surface layer of Pt(1 1 1) reduces the binding energy of CO by a few kcal/mol. IRAS data show two C-O stretching frequencies, â¼2100 and â¼1860 cmâ1, corresponding to atop and bridge bonded species, respectively. Bridge bonded stretching frequencies are only observed for Pt(1 1 1) and (2 Ã 2) Sn/Pt(1 1 1) alloy surfaces. A slight coverage dependence of the vibrational frequencies is observed for the three surfaces. High pressure IRAS experiments over a broad temperature range show no indication of bridge bonded CO on any of the three surfaces. Direct CO adsorption on Sn sites is not observed over the measured temperature and pressure ranges.
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Physical Sciences and Engineering
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Physical and Theoretical Chemistry
Authors
Adrian Hightower, M. Dolores Perez, Bruce E. Koel,