Pt and Pd decorated Au nanowires: Extremely high activity of ethanol oxidation in alkaline media

Highly ordered Pt and Pd decorated Au nanowire arrays, Pt/Au NWA and Pd/Au NWA, are prepared by anodized aluminum oxide (AAO) template based electrodeposition combined with chemical reduction. The effect of shell material on the ethanol oxidation currents is studied. The maximum current densities are several times higher on the modified electrodes than on the unmodified Pt (Pd) NWA. The most highly active electrode shows almost 4-fold increase in the ethanol peak current. Pt/Au and Pd/Au NWA electrodes show a similar dependence of the ethanol oxidation current density on the Pd or Pt deposition time, which most likely, reflects the optimal upper layer thickness. The synergistic effect between substrate and deposit materials seems to be the most important factor explaining such unusually high activity. (C) 2011 Elsevier Ltd. All rights reserved.