CO adsorption and dissociation on iron oxide supported Pt particles |
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Authors: | Y-N Sun H-J Freund |
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Institution: | Abteilung Chemische Physik, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, Berlin 14195, Germany |
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Abstract: | We studied CO adsorption on Pt particles deposited on well-ordered Fe3O4(1 1 1) thin films grown on Pt(1 1 1) by temperature programmed desorption (TPD). A highly stepped Pt(1 1 1) surface produced by ion sputtering and annealing at 600 K was studied for comparison. Structural characterization was performed by scanning tunneling microscopy and Auger electron spectroscopy. The TPD spectra revealed that in addition to the desorption peaks at ∼400 and 480 K, assigned to CO adsorbed on Pt(1 1 1) facets and low-coordination sites respectively, the Pt nanoparticles annealed at 600 K exhibit a desorption state at ∼270 K. This state is assigned to initial stages of strong metal support interaction resulting in partial Fe-Pt intermixing. On both Pt/Fe3O4(1 1 1) and stepped Pt(1 1 1) surfaces CO is found to dissociate at 500 K. The results suggest that CO dissociation and carbon accumulation occur on the low-coordinated Pt sites. |
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Keywords: | Platinum Iron oxides CO adsorption CO dissociation Strong metal support interaction |
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