Influence of the Adsorbate Structure and Surface Barrier at Micropores : The Adsorption on Columnar-Structured Gold Electrodes of Pyridine from Aqueous Perchlorate Ion-Containing Solutions
The electroadsorption on columnar Au electrodes (substrate) of pyridine from x M pyridine + 0.1 M HClO<sub>4</sub> and x M pyridine + 0.1 M KClO<sub>4</sub> aqueous solutions (10<sup>-3</sup> e x e 10<sup>-2</sup>), at constant potential and 298 K, was...
Guardado en:
| Autores principales: | , , , , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
1997
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/121285 |
| Aporte de: |
| Sumario: | The electroadsorption on columnar Au electrodes (substrate) of pyridine from x M pyridine + 0.1 M HClO<sub>4</sub> and x M pyridine + 0.1 M KClO<sub>4</sub> aqueous solutions (10<sup>-3</sup> e x e 10<sup>-2</sup>), at constant potential and 298 K, was studied using voltammetry, chronocoulometry, and ac impedance combined with scanning tunneling microscopy to characterize the substrate topography. For a constant pyridine concentration (c), the degree of surface coverage by pyridine adsorbate (θ) diminished as R was increased. The θ vs c plots, irrespective of R, were interpreted by a Frumkin adsorption isotherm including a constant standard adsorption free energy. The evaluation of adsorption isotherms reflects the existence of an excluded volume effect, which can be related to a barrier effect due to adsorbates at nanometer size pore entrances. |
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