Effect of the electrolyte composition on the electroreduction of palladium oxide films

• Autores: Bolzán, A. E.; Arvia, Alejandro Jorge
• Año de publicación: 1993
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Ciencias Exactas; Química; Palladium oxide films; Voltammetric electroreduction profiles
• Institución: Universidad Nacional de La Plata

The voltammetric electroreduction of Pd oxide layers grown at 2.00 V (RHE) was studied in H₂SO₄ and HClO₄ solutions containing different concentrations of LiClO₄, Na₂SO₄ and KHSO₄. The voltammetric electroreduction profiles show two main regions; the first is in the range 1.2–1.6 V and is related to the electroreduction of a fast redox system; the second region extends through the range 1.1-0.40 V, where the electroreduction of the thick oxide matrix takes place. This latter process is strongly affected by the solution composition, including the pH, in a manner contrasting to the effect on Pd oxide growth. The thick oxide layer electroreduction charge increases as the solution pH is decreased. These results are discussed in terms of specific interaction between sulphate ions and the oxide layer, so that the electroreduction process is favoured owing to the likely formation of sulphate-containing complex species.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas