Effect of Non-Specifically Adsorbed Ions on the Surface Oxidation of Pt(111)

Authors

  • Dr. Masashi Nakamura,

    Corresponding author
    1. Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, Yayoi-cho 1-33 Inage-ku, Chiba 263-8522 (Japan)
    • Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, Yayoi-cho 1-33 Inage-ku, Chiba 263-8522 (Japan)
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  • Yo Nakajima,

    1. Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, Yayoi-cho 1-33 Inage-ku, Chiba 263-8522 (Japan)
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  • Prof. Dr. Nagahiro Hoshi,

    1. Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, Yayoi-cho 1-33 Inage-ku, Chiba 263-8522 (Japan)
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  • Dr. Hiroo Tajiri,

    1. Research and Utilization Division, Japan Synchrotron Radiation Research Institute, Sayo-gun, Hyogo (Japan)
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  • Dr. Osami Sakata

    1. Synchrotron X-ray Station at SPring-8, National Institute for Material Science, Sayo-gun, Hyogo (Japan)
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Abstract

The oxidation processes of a Pt(111) electrode in alkaline electrolytes depend on non-specifically adsorbed ions according to in situ X-ray diffraction and infrared spectroscopic measurements. In an aqueous solution of LiOH, an OHad adlayer is formed in the first oxidation step of the Pt(111) electrode as a result of the strong interaction between Li+ and OHad, whereas Pt oxidation proceeds without OHad formation in CsOH solution. Structural analysis by X-ray diffraction indicates that Li+ is strongly protective against surface roughening caused by subsurface oxidation. Although Cs+ is situated near the Pt surface, the weak protective effect of Cs+ results in irreversible surface roughening due to subsurface oxidation.

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