Initial stages of Pt(111) electrooxidation: dynamic and structural studies by surface X-ray diffraction
Date
2017
Authors
Drneca, Jakub
Ruge, Martin
Reikowski, Finn
Rahn, Bjorn
Carla, Francesco
Felici, Roberto
Stettner, Jochim
Magnussen, Olaf M.
Harrington, David A.
Journal Title
Journal ISSN
Volume Title
Publisher
Electrochimica Acta
Abstract
In-situ surface X-ray diffraction is used to characterize the surface oxides on a Pt(111) surface in 0.1 M HClO4. Detailed analysis at two potentials confirms that the surface restructuring in the initial oxidation stages is consistent with a place exchange process between Pt and O atoms, and the exchanged Pt atoms are located above their original positions in the Pt(111) lattice. The (1,1,1.5) reflection is used to dynamically study the surface during cyclic voltammetry. The restructuring associated with the place exchange initiates with the CV peak at 1.05 V, even though multiple cycles to 1.17 V lead to no changes in the CV. The restructuring is reversible below a critical coverage of place exchanged Pt atoms, which we estimate to be between 0.07 and 0.15 ML. Extensive cycling to potentials higher or equal to 1.17 V leads to progressive disordering of the surface.
Description
Keywords
Pt(111) oxidation, Oxide, Place exchange, Surface X-ray diffraction
Citation
Drnec, J., Ruge, M., Reikowski, F., Rahn, B., Carla, F., Felici, R., Stettner, J., Magnussen, O. & Harrington, D.A. (2017). Initial stages of Pt(111) electrooxidation: dynamic and structural studies by surface X-ray diffraction. Electrochimica Acta, 224, 220-227. https://doi.org/10.1016/j.electacta.2016.12.028