W@Au Nanostructures Modifying Carbon as Materials for Hydrogen Peroxide Electrogeneration

Abstract

In this work, materials based on core-shell W@Au type structures were found to have promise for use as electrocatalysts on the in-situ production of H2O2 by means of the oxygen reduction reaction (ORR). We describe herein the synthesis and characterization of these materials and then present a study of electrocatalytic activity towards ORR by the electrogeneration of H2O2 employing these materials supported on Vulcan XC-72R carbon corresponding to 1 and 2 wt% loading. The use of W@Au/C materials led to higher activity compared to pure carbon and commercial Pt/C, and the optimal load is 1%, which presented the highest ring current for the ORR using the rotating ring-disk electrode technique. Exhaustive electrolysis using a W@Au/C 1% gas diffusion electrode (GDE) was employed to verify the real amount of H2O2 electrogenerated comparing with a Vulcan XC-72R GDE. We verified that the W@Au/C 1% material is able to generate 50% more H2O2 than carbon. These results can be explained based on synergistic interactions presented by the W@Au/C 1% material and also by both conductivity and hydrophilicity differences provided by the nanostructures supported on carbon.