Regensburg 2022 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 20: Poster Monday: Solid-Liquid Interfaces
O 20.4: Poster
Montag, 5. September 2022, 18:00–20:00, P4
In situ surface X-ray diffraction studies of Pt(110) — •Jan Ole Fehrs1, Timo Fuchs1, Jakub Drnec2, Marta Mirolo2, Serhiy Cherevko3, Valentin Briega3, David Harrington4, Chentian Yuan4, and Olaf Magnussen1 — 1Christian-Albrechts Universität zu Kiel, Germany — 2European Synchrotron Radiation Facility, Grenoble, France — 3Helmholtz Institute Erlangen-Nürnberg for Renewable Energy, Germany — 4University of Victoria, Canada
The surface oxidation of platinum is an important process in the degradation of platinum electrocatalysts in PEM fuel cells. Previously, the oxidation of the (111) and (100) surfaces of platinum was investigated by Fuchs et al. to understand the underlying mechanisms and growth of the oxide structures. In this work the (110) surface was studied by similar in situ high energy surface X-ray diffraction (HESXRD) at the ID31 beamline of the European Synchrotron Radiation Facility. Unreconstructed as well as (1x2)-reconstructed Pt(110) surfaces were prepared and their restructuring upon oxidation was examined. Distinct differences in this restructuring of the unreconstructed and the (1x2)-reconstructed surface were found. The changes in occupancy of the topmost surface layers after one oxidation/reduction cycle are greater for the unreconstructed surface than for the reconstructed surface, suggesting that the latter is more stable upon oxidation. In accordance with this result, it was also found that the missing row reconstruction of the surface was only lifted during the reduction of the surface oxide.