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Estudios cinéticos de la reacción del electrodo de hidrógeno en junturas heteroátomicas de electrodos bi-componentes

Mariela Alicia Brites Helú José Luis Fernández Sergio Alberto Dassie Fernando Gabriel Fungo Sebastián Enrique Collins Abel Cesar Chialvo

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Resumen/Descripción – provisto por el repositorio digital
This work studies the synergetic interactions between PGM catalysts (Pt, Rh) and Au over both branches of the Hydrogen Electrode Reaction (HER): the Hydrogen Oxidation Reaction (hor) and the Hydrogen Evolution Reaction (her) in acid and alkaline media. The electrodes analyzed have the particular feature of maximized lengths of the junctions between their two components under the following electrode configurations: supported nanoparticles ensembles and bi-metallic ordered arrays. The first systems were based on short-pulse sputtering of Pt and Au NPs onto HOPG, glassy carbon and metals supports. The second configuration was achieved by SECM micro-writing and mask-assisted electron beam lithography methods. Different and complementary electrochemical measurements were carried out to determinate the fundamental aspects of the junction contributions to the global electrocatalytic activity. Nanoparticles ensembles were analyzed by supporting them on microelectrodes and by scanning electrochemical microscopy. The ordered arrays were studied by mounting on rotating disc electrodes. The obtained results were analyzed using kinetic models based on rigorous treatments of the whole reaction mechanism. On the one hand, through the correlation of the experimental curves was possible to detect variations on the values of the kinetic parameters which could be caused by the interfaces. On the other hand, through the concept of excess electrocatalytic activity these changes were observed more directly. Pt and Rh modifie the performance of gold in the her and hor. In acid media the changes are associated with the electro-adsorption of H from H2 while in alkaline media the H-chemisorption from H2 is modified.
Palabras clave – provistas por el repositorio digital

HER; Arrays; NPs ensembles; Junctions; Excess current; Arreglos ordenados; Ensambles; Juntura; Corriente de exceso

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No requiere 2018 Biblioteca Virtual de la Universidad Nacional del Litoral (SNRD) acceso abierto

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Tipo de recurso:

tesis

Idiomas de la publicación

  • español castellano

País de edición

Argentina

Fecha de publicación