Chemical evidence of hydrogen sorption processes on potential cycled gold electrodes

Transient activation of polycrystalline gold electrodes for the hydrogen electrode reaction, produced either through potentiostatic or potentiodynamic treatment, is related to the adsorption of H atoms and its penetration into the bulk. Evidence for H atoms results from the application of silver crystal decoration technique. Hydrogen-loaded activated gold electrodes in contact with a soluble silver salt solution yield silver deposits which can be studied through conventional voltammetric stripping. The increase in activation for the HER correlates with the increase in the voltammetric contribution of 0 electroadsorption peak assigned to the (110) crystallographic face of gold. The development of a faceted surface structure with preferred orientation in the direction of the less dense atomic arrangement apparently favours the penetration of hydrogen into the bulk metal.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada