Synthesis of nano-size tungsten oxide and its evaluation as an electrocatalyst support for oxygen reduction in acid media
© ACS Catalysis, 2012, American Chemical Society.
William E, Mustain (2012). Synthesis of Nanosize Tungsten Oxide and Its Evaluation as an Electrocatalyst Support for Oxygen Reduction in Acid Media. ACS Catalysis, 2(3), 456-463.
WO3 was investigated as a possible support material for monolayer Pt ORR electrocatalysts in acid electrolyte. It was found that as-prepared Pt/WO3 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/WO3 electrocatalyst showed significant performance degradation that was tied directly to the formation of water-soluble hydrogen tungsten bronze (HxWO3) on the support surface that was identified by X-ray 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 WO3 supports in acid media, which is relevant for proton exchange membrane (PEM) fuel cells.