Effects of Adsorbate Coverage and Bond-Length Disorder on the d-Band Center of Carbon-Supported Pt Catalysts
| Autor: | Matthew W. Small, John J. Rehr, Joshua J. Kas, Anatoly I. Frenkel, Kristina O. Kvashnina, Moniek Tromp, Ralph G. Nuzzo |
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| Rok vydání: | 2014 |
| Předmět: |
X-ray absorption spectroscopy
Chemistry Scattering Fermi level Analytical chemistry chemistry.chemical_element Atomic and Molecular Physics and Optics Catalysis Resonant inelastic X-ray scattering Bond length symbols.namesake Atomic electron transition Chemical physics symbols Physical and Theoretical Chemistry Platinum |
| Zdroj: | ChemPhysChem. 15:1569-1572 |
| ISSN: | 1439-4235 |
| DOI: | 10.1002/cphc.201400055 |
| Popis: | Determination of the factors that affect the d-band center of catalysts is required to explain their catalytic properties. Resonant inelastic X-ray scattering (RIXS) enables direct imaging of electronic transitions in the d-band of Pt catalysts in real time and in realistic environmental conditions. Through a combination of in situ, temperature-resolved RIXS measurements and theoretical simulations we isolated and quantified the effects of bond-length disorder and adsorbate coverage (CO and H2) on the d-band center of 1.25 nm size Pt catalysts supported on carbon. We found that the decrease in adsorbate coverage at elevated temperatures is responsible for the d band shifts towards higher energies relative to the Fermi level, whereas the effect of the increase in bond-length disorder on the d-band center is negligible. Although these results were obtained for a specific case of non-interacting support and weak temperature dependence of the metal-metal bond length in a model catalyst, this work can be extended to a broad range of real catalysts. |
| Databáze: | OpenAIRE |
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