Synthesis of Nanosize Tungsten Oxide and Its Evaluation as an Electrocatalyst Support for Oxygen Reduction in Acid Media

Abstract

WO 3 was investigated as a possible support material for monolayer Pt ORR electrocatalysts in acid electrolyte. It was found that as-prepared Pt/WO 3 showed enhanced activity for the ORR and superior electron transfer ability compared to conventional Pt/C and bulk polycrystalline Pt. However, similar to other tungsten derived supports, most notably WC, the Pt/WO 3 electrocatalyst showed significant performance degradation that was tied directly to the formation of water-soluble hydrogen tungsten bronze (H x WO 3 ) on the support surface that was identified by Xray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). This information, combined with previous work by our group on WC supports, are also combined to propose a series degradation pathway for WC and WO 3 supports in acid media, which is relevant for proton exchange membrane (PEM) fuel cells.

The role of the WO3 nanostructures in the oxygen reduction reaction and PEM fuel cell performance on WO3–Pt/C electrocatalysts

“…It is clear that the binding energy of Pt 4f and W 4f peaks shifted with the contact of the platinum nanoparticles and the oxide, probably due to the electronic interactions between them. This phenomena has been observed by other authors, and has been related to a Strong Metal Support Interaction (SMSI) between metallic nanoparticles such as Pt or Pd and WO 3 [13,16,20,22]. This kind of "metalsupport interaction" can modify the electronic and catalytic properties of metal nanoparticles [13,22] and produces an enhance in the intrinsic activity of Pt for the ORR.…”

Graphene-based transition metal oxide nanocomposites for the oxygen reduction reaction

“…In order to obtain clear images within the nanoscale or even smaller, TEM and HRTEM are suitable to provide a considerably more comprehensive and descriptive view of nanocomposites from the microstructure of transition metal oxides and the crystal lattice arrangement or defects on graphene sheets. 93,94 For example, Fig. 11 shows the high resolution TEM images processed with an FFT bandpass filter of a suspended single layer of graphene, GO, and reduced and annealed graphene oxide (raGO).…”

Advances in Ceramic Supports for Polymer Electrolyte Fuel Cells

“…The performance of this system was compared to Pt/XC-72 and showed very high stability in acidic conditions. Nano-sized WO3 was also studied as a possible support material for monolayer Pt ORR electro-catalysts in acid electrolyte [61]. Pt/WO3 exhibited good activity for ORR and superior electron transfer capability compared to conventional Pt/C and Pt.…”