Calculated Phase Diagrams for the Electrochemical Oxidation and Reduction of Water over Pt(111)

Department of Physics, Technical University of Denmark, Lyngby, Capital Region, Denmark
The Journal of Physical Chemistry B (Impact Factor: 3.3). 12/2006; 110(43):21833-9. DOI: 10.1021/jp0631735
Source: PubMed


Ab initio density functional theory is used to calculate the electrochemical phase diagram for the oxidation and reduction of water over the Pt(111) surface. Three different schemes proposed in the literature are used to calculate the potential-dependent free energy of hydrogen, water, hydroxyl, and oxygen species adsorbed to the surface. Despite the different foundations for the models and their different complexity, they can be directly related to one another through a systematic Taylor series expansion of the Nernst equation. The simplest model, which includes the potential only as a shift in the chemical potential of the electrons, accounts very well for the thermochemical features determining the phase-diagram.

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Available from: Christopher D. Taylor, Nov 17, 2014
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    • "It is thought, that the main role of Ru and Sn in these alloys is to activate water, generating surface-bound hydroxyl intermediate (OH*), which assists in C 1 oxidation [94] [95] [96] [97] [98]. On pure Pt, the activation of water to form surface hydroxyl intermediates occurs at potentials > 0.63 V. DFT calculated phase diagrams of the water/Pt(1 1 1) interface indicate that water is the most stable surface intermediate between 0.08 and 0.63 V [99]. "
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