Driving Force of the Initial Step in Electrochemical Pt(111) Oxidation

The first step of electrochemical surface oxidation is extraction of a metal atom from its lattice site to a location in a growing oxide. Here we show by fast simultaneous electrochemical and in situ high-energy surface X-ray diffraction measurements that the initial extraction of Pt atoms from Pt(111) is a fast, potential-driven process, whereas charge transfer for the related formation of adsorbed oxygen-containing species occurs on a much slower time scale and is evidently uncoupled from the extraction process. It is concluded that potential plays a key independent role in electrochemical surface oxidation.

Automated summary

The initial step of electrochemical surface oxidation involves the extraction of metal atoms from their lattice sites to form a growing oxide. By conducting fast simultaneous electrochemical and in situ high-energy surface X-ray diffraction measurements, it has been demonstrated that the extraction of Pt atoms from Pt(111) is a fast process driven by potential, while the charge transfer for the formation of oxygen-containing species occurs at a much slower rate and appears to be decoupled from the extraction process. It is thus concluded that potential plays an independent and crucial role in electrochemical surface oxidation.