INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
artículos
Título:
Energetic and entropic contributions to the underpotential/overpotential deposition shifts on single crystal surfaces from lattice dynamics
Autor/es:
OSCAR ALEJANDRO OVIEDO; EZEQUIEL PEDRO MARCOS LEIVA; MARIANA ISABEL ROJAS
Revista:
ELECTROCHIMICA ACTA
Editorial:
Elsevier
Referencias:
Año: 2006 vol. 51 p. 3526 - 3536
ISSN:
0013-4686
Resumen:
Electrochimical deposition of a metal on a foreign substrate may occur before or after the Nerst reversible potential, depending on the chemical nature of the substrate and adsorbate in question. Statistical mechanic treatment and a proper description of interactions between the particles of the system are necessary for an adequate theoretical representation of the electrochemical systems. In the present work, changes in relevant thermodynamic properties due to adsorption of a metal on foreign single crystal (hkl) metallic surface are studied for a number of system of electrochemical interest by means of quasi-harmonic (QH) lattice dynamics calculations with embedded atom position at 300K. The metal couples considered involve silver, gold, platinum, palladium and copper. Underpotential and overpotential deposition trends observed for this set of transition metal systems are analyzed taking into account the changes in the internal energies and the entropic contributions due to deposition process. The possibility of obtaining entropic information from measurements at different temperatures is also discussed.