Atomic engineering of platinum alloy surfaces
A major practical challenge in heterogeneous catalysis is to minimize the loading of expensive platinum group metals (PGMs) without degrading the overall catalytic efficiency. Gaining a thorough atomic-scale understanding of the chemical/structural changes occurring during catalyst manufacture/opera...
| Asıl Yazarlar: | , , , , |
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| Materyal Türü: | Journal article |
| Dil: | English |
| Baskı/Yayın Bilgisi: |
2013
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| _version_ | 1826260301501169664 |
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| author | Li, T Bagot, P Marquis, E Edman Tsang, S Smith, G |
| author_facet | Li, T Bagot, P Marquis, E Edman Tsang, S Smith, G |
| author_sort | Li, T |
| collection | OXFORD |
| description | A major practical challenge in heterogeneous catalysis is to minimize the loading of expensive platinum group metals (PGMs) without degrading the overall catalytic efficiency. Gaining a thorough atomic-scale understanding of the chemical/structural changes occurring during catalyst manufacture/operation could potentially enable the design and production of "nano-engineered" catalysts, optimized for cost, stability and performance. In the present study, the oxidation behavior of a Pt-31 at% Pd alloy between 673-1073. K is investigated using atom probe tomography (APT). Over this range of temperatures, three markedly different chemical structures are observed near the surface of the alloy. At 673. K, the surface oxide formed is enriched with Pd, the concentration of which rises further following oxidation at 773. K. During oxidation at 873. K, a thick, stable oxide layer is formed on the surface with a stoichiometry of PdO, beneath which a Pd-depleted (Pt-rich) layer exists. Above 873. K, the surface composition switches to enrichment in Pt, with the Pt content increasing further with increasing oxidation temperature. This treatment suggests a route for tuning the surfaces of Pt-Pd nanoparticles to be either Pd-rich or Pt-rich, simply by adjusting the oxidation temperatures in order to form two different types of core-shell structures. In addition, comparison of the oxidation behavior of Pt-Pd with Pt-Rh and Pd-Rh alloys demonstrates markedly different trends under the same conditions for these three binary alloys. © 2012. |
| first_indexed | 2024-03-06T19:03:25Z |
| format | Journal article |
| id | oxford-uuid:1453c978-0806-4319-b0d7-35f7a7c36f8e |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:03:25Z |
| publishDate | 2013 |
| record_format | dspace |
| spelling | oxford-uuid:1453c978-0806-4319-b0d7-35f7a7c36f8e2022-03-26T10:19:01ZAtomic engineering of platinum alloy surfacesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:1453c978-0806-4319-b0d7-35f7a7c36f8eEnglishSymplectic Elements at Oxford2013Li, TBagot, PMarquis, EEdman Tsang, SSmith, GA major practical challenge in heterogeneous catalysis is to minimize the loading of expensive platinum group metals (PGMs) without degrading the overall catalytic efficiency. Gaining a thorough atomic-scale understanding of the chemical/structural changes occurring during catalyst manufacture/operation could potentially enable the design and production of "nano-engineered" catalysts, optimized for cost, stability and performance. In the present study, the oxidation behavior of a Pt-31 at% Pd alloy between 673-1073. K is investigated using atom probe tomography (APT). Over this range of temperatures, three markedly different chemical structures are observed near the surface of the alloy. At 673. K, the surface oxide formed is enriched with Pd, the concentration of which rises further following oxidation at 773. K. During oxidation at 873. K, a thick, stable oxide layer is formed on the surface with a stoichiometry of PdO, beneath which a Pd-depleted (Pt-rich) layer exists. Above 873. K, the surface composition switches to enrichment in Pt, with the Pt content increasing further with increasing oxidation temperature. This treatment suggests a route for tuning the surfaces of Pt-Pd nanoparticles to be either Pd-rich or Pt-rich, simply by adjusting the oxidation temperatures in order to form two different types of core-shell structures. In addition, comparison of the oxidation behavior of Pt-Pd with Pt-Rh and Pd-Rh alloys demonstrates markedly different trends under the same conditions for these three binary alloys. © 2012. |
| spellingShingle | Li, T Bagot, P Marquis, E Edman Tsang, S Smith, G Atomic engineering of platinum alloy surfaces |
| title | Atomic engineering of platinum alloy surfaces |
| title_full | Atomic engineering of platinum alloy surfaces |
| title_fullStr | Atomic engineering of platinum alloy surfaces |
| title_full_unstemmed | Atomic engineering of platinum alloy surfaces |
| title_short | Atomic engineering of platinum alloy surfaces |
| title_sort | atomic engineering of platinum alloy surfaces |
| work_keys_str_mv | AT lit atomicengineeringofplatinumalloysurfaces AT bagotp atomicengineeringofplatinumalloysurfaces AT marquise atomicengineeringofplatinumalloysurfaces AT edmantsangs atomicengineeringofplatinumalloysurfaces AT smithg atomicengineeringofplatinumalloysurfaces |