Electroreduction of oxygen at tungsten oxide modified carbon-supported RuSex nanoparticles

• DOI: 10.1007/s10800-007-9349-6
• Publication Date: 2007-07-02T12:03:50Z
• Authors: P. J. Kulesza; K. Miecznikowski; B. Baranowska; M. Skunik; A. Kolary-Zurowska; A. Lewera; K. Karnicka; M. Chojak; I. Rutkowska; S. Fiechter; P. Bogdanoff; I. Dorbandt; G. Zehl; R. Hiesgen; E. Dirk; K. S. Nagabhushana; H. Boennemann
• Keywords: Glassy carbon; Rotating disk electrode; Nafion; Carbon fibers; Rotating ring-disk electrode; Ruthenium oxide

WO3-modified carbon-supported bi-component ruthenium–selenium, RuSex (Ru, 20; Se, 1 wt%), nanoparticles were dispersed in the form of Nafion-containing inks on glassy carbon electrodes to produce electrocatalytic interfaces reactive towards electroreduction of dioxygen in acid medium (0.5 mol dm−3 H2SO4). It was apparent from the rotating disk voltammetric experiments that the reduction of oxygen proceeded at WO3-modified electrocatalyst at more than 100 mV more positive potential when compared to bare (WO3-free) RuSex system (that had been prepared under analogous conditions and deposited at the same loading of 156 μg cm−2). The ring-disk rotating voltammetric measurements show that, while the production of hydrogen peroxide intermediate was significantly lower, the kinetic parameter (heterogeneous rate constant) for the oxygen reduction was higher for WO3-modified RuSex (relative to bare RuSex). Comparison was also made to highly-efficient Vulcan-supported Pt or Pt/Co nanoparticles: while the half-wave potential for the oxygen reduction at WO3-modified carbon-supported RuSex was still more negative relative to the potentials characteristic of Pt-based electrocatalysts, the oxygen reduction rotating disk voltammetric current densities (measured at 1600 rpm) were almost identical.