Oxygen Reduction Activity of Vapor-Grown Platinum Nanotubes

Supportless platinum nanotubes (PtNTs) were synthesized by the decomposition of platinum acetylacetonate vapor within anodic alumina templates at 210 degrees C. As synthesized, the nanotubes are nanoparticulate aggregates composed of Pt crystallites approximately 3 nm in diameter and with a range of lengths from 1 mu m to 20 mu m. Annealing treatments result in crystallite growth and morphological evolution of the tubular nanostructures including the development of nanoscale porosity. In rotating disk electrode measurements carried out in 0.1MHClO(4), porous PtNTs annealed at 500 degrees C exhibited a specific activity for oxygen reduction of 2390 +/- 423 mu A/cm(Pt)(2) at 0.9 V, comparable to bulk polycrystalline Pt. The electrochemical surface area of the annealed structures was a relatively low 10 m(2)/g, resulting in a moderate overall mass activity of 240 +/- 41 mA/mg(Pt). (C) 2013 The Electrochemical Society. All rights reserved.