Ruge, MartinDrnec, JakubRahn, BjörnReikowski, FinnHarrington, David A.Carlà, FrancescoFelici, RobertoStettner, JochimMagnussen, Olaf M.2019-02-032019-02-0320172017Ruge, 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/10.1149/2.0741709jeshttp://dx.doi.org/10.1149/2.0741709jeshttp://hdl.handle.net/1828/10579The 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.enGISAXSOxidePlace exchangePt(111) oxidationSurface X-ray diffractionArticle