Electrochemical Oxidation of Smooth and Nanoscale Rough Pt(111): An In Situ Surface X-ray Scattering Study
Date
2017
Authors
Ruge, Martin
Drnec, Jakub
Rahn, Björn
Reikowski, Finn
Harrington, David A.
Carlà, Francesco
Felici, Roberto
Stettner, Jochim
Magnussen, Olaf M.
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of The Electrochemical Society
Abstract
The potential dependent surface structure of Pt(111) electrodes in electrochemical environment was studied by in situ crystal truncation rod measurements and in operando grazing incidence small angle X-ray scattering. Determination of the interface structure in the oxidation region reveal a continuous increase of the coverage of place exchanged atoms toward more positive potentials. The resulting oxide consists of an oxygen rich outer and a Pt-rich inner atomic layer. With increasing potential the oxide approaches a more uniform stoichometry. While place exchange on atomically smooth terraces only occurs above 1.05 V, structural changes of 3D Pt islands, grown by repetitive oxidation/reduction cycles, already commence at 0.8 V, which is assigned to oxidation at Pt steps. Evolution of the 3D island distribution occurs in all stages of the cycles: Whereas Pt oxidation leads to narrowing of the lateral size distribution, vertical island growth occurs during the subsequent reduction.
Description
Keywords
GISAXS, Oxide, Place exchange, Pt(111) oxidation, Surface X-ray diffraction
Citation
Ruge, M., Drnec, J., Rahn, B., Reikowski, F., Harrington, D.A., Carlà, F., Felici, R., Stettner, J. & Magnussen, O.M. (2017). Electrochemical Oxidation of Smooth and Nanoscale Rough Pt(111): An In Situ Surface X-ray Scattering Study. Journal of The Electrochemical Society, 164(9), H608-H614. http://dx.doi.org/10.1149/2.0741709jes