Artículo
Super-Nernstian Shifts of Interfacial Proton-Coupled Electron Transfers: Origin and Effect of Noncovalent Interactions
Autor/es | Wildi, Christopher
Cabello, Gema Zoloff Michoff, Martín E. Vélez, Patricio Leiva, Ezequiel P.M. Calvente Pacheco, Juan José Andreu Fondacabe, Rafael Jesús Cuesta, Angel |
Departamento | Universidad de Sevilla. Departamento de Química Física |
Fecha de publicación | 2016 |
Fecha de depósito | 2022-06-03 |
Publicado en |
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Resumen | Anions whose specific adsorption involves a proton-coupled electron transfer (PCET) include adsorbed OH (OHad), which plays an enormously relevant role in many fuel-cell reactions. OHad formation has often been found to ... Anions whose specific adsorption involves a proton-coupled electron transfer (PCET) include adsorbed OH (OHad), which plays an enormously relevant role in many fuel-cell reactions. OHad formation has often been found to happen in alkaline solutions at potentials more negative than expected from a Nerstian shift, and this has been proposed as the reason for the often easier oxidation of organic molecules in alkaline media, as compared to acids. Noncovalent interactions with electrolyte cations have also been shown to affect the stability of OHad. Using cyanide-modified Pt(111) as a model, we show here that interfacial PCETs will show a super-Nernstian shift if (i) less than one electron per proton is transferred and (ii) the plane of proton-electron transfer and that of the metal surface do not coincide. We also show that electrolyte cations have a double effect: they provoke an additional shift by blocking the site of transfer but decrease the super-Nernstian contribution by separating the plane of transfer from the outer Helmholtz plane. |
Agencias financiadoras | Universidad Nacional de Córdoba |
Identificador del proyecto | CONICET- PIP 11220110100992
PICT 2012-2324 PME 2006-01581 |
Cita | Wildi, C., Cabello, G., Zoloff Michoff, M.E., Vélez, P., Leiva, E.P.M., Calvente Pacheco, J.J.,...,Cuesta, A. (2016). Super-Nernstian Shifts of Interfacial Proton-Coupled Electron Transfers: Origin and Effect of Noncovalent Interactions. Journal of Physical Chemistry C, 120 (29), 15586-15592. |
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