Resumo

SUSTERSIC, Maria G; ZANON, Thelma A; ALBANO, Sonia G  e  VON MENGERSHAUSEN, Alicia E. Hydrogen underpotential deposition on preferentially oriented polycrystalline gold. Inf. tecnol. [online]. 2008, vol.19, n.5, pp. 49-60. ISSN 0718-0764.  doi: 10.4067/S0718-07642008000500007.

Hydrogen deposition at lower potentials than those corresponding to the hydrogen evolution reaction on polycrystalline gold whose surface has been preferentially oriented according to the three low index planes, has been studied. Several processes contribute to the anodic and cathodic currents at the double layer charging potential region: the specific anion adsorption and desorption, the lift of surface reconstruction, the hydrogen oxidation and the hydrogen underpotential deposition. The relative heights of different current contributions change with the surface preferential orientation. The hydrogen oxidation peaks grow continuously while those corresponding to the lift of surface reconstruction reach a limited height. These facts allow distinguishing the faradic current contributions from the capacitive current contributions at the double layer charging potentials in 0.5 M sulphuric acid solution.

Palavras-chave : hydrogen deposition; gold electrodes; surface reconstruction; electric double layer.