Co oxidation on spontaneous Pt–Ru deposits on composite polymeric electrodes

Composite polyaniline electrodes containing carbon nanotubes incorporated in the film and spontaneous Pt–Ru deposits as catalytic material for CO oxidation are reported.PANI films were electrosynthesized from a monomer acid solution with the addition of carbon nanotubes. Then, Pt–Ru deposits were obtained by immersing the polymeric film in H2PtCl6 and/or RuCl3 in HCl. Three series of deposits were prepared by either immersion in a solution containing both metallic ions during a fixed time or successive immersion in different solutions containing only one of the metallic ions during half of the established time and varying the sequence as follows: (i) first in H2PtCl6 and then in RuCl3 or (ii) first in RuCl3 and then in H2PtCl6. Adsorbed CO oxidation was studied by cyclic voltammetry in H2SO4 solution.The electrodes were characterized through SEM and EDX. The different ways to obtain spontaneous Pt–Ru deposits are analyzed and their influence on CO oxidation is discussed.