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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Electronic and structural study of Pt-modified Au vicinal surfaces: a model system for Pt-Au catalysts

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Prieto, Mauricio J. [1] ; Carbonio, Emilia A. [1] ; Fatayer, Shadi [1] ; Landers, Richard [1] ; de Siervo, Abner [1]
Total Authors: 5
[1] Univ Estadual Campinas, Inst Fis Gleb Wataghin, Dept Fis Aplicada, BR-13083859 Campinas, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Physical Chemistry Chemical Physics; v. 16, n. 26, p. 13329-13339, 2014.
Web of Science Citations: 9

Two single crystalline surfaces of Au vicinal to the (111) plane were modified with Pt and studied using scanning tunneling microscopy (STM) and X-ray photoemission spectroscopy (XPS) in ultra-high vacuum environment. The vicinal surfaces studied are Au(332) and Au(887) and different Pt coverage (yPt) were deposited on each surface. From STM images we determine that Pt deposits on both surfaces as nanoislands with heights ranging from 1 ML to 3 ML depending on yPt. On both surfaces the early growth of Pt ad-islands occurs at the lower part of the step edge, with Pt ad-atoms being incorporated into the steps in some cases. XPS results indicate that partial alloying of Pt occurs at the interface at room temperature and at all coverage, as suggested by the negative chemical shift of Pt 4f core line, indicating an upward shift of the d-band center of the alloyed Pt. Also, the existence of a segregated Pt phase especially at higher coverage is detected by XPS. Sample annealing indicates that the temperature rise promotes a further incorporation of Pt atoms into the Au substrate as supported by STM and XPS results. Additionally, the catalytic activity of different PtAu systems reported in the literature for some electrochemical reactions is discussed considering our findings. (AU)

FAPESP's process: 12/16860-6 - Study of the electronic and atomic structure of tetraphenyl porfirin nanoribbons self-assembled on vicinal surfaces
Grantee:Shadi Passam Fatayer
Support Opportunities: Scholarships in Brazil - Master
FAPESP's process: 07/54829-5 - Electronic and geometric structure of nano-materials: synchrotron radiation studies
Grantee:Richard Landers
Support Opportunities: Research Projects - Thematic Grants