Peroxide and oxygen reduction on electrode surfaces

Oxygen reduction is a theme that pervades many areas, e.g., reduction of oxygen at electrode surfaces, which is a requirement for efficient fuel cells. The mechanism of oxygen and peroxide reduction on bare Pt and on Au surfaces modified with ordered metal monolayers was presented. By using a combination of spectroscopic, imaging, and X-ray scattering techniques combined with detailed calculations, a crucial step involved the spontaneous cleavage of the O-O bond to form a mixed metal-hydroxide complex. This hydroxide complex was reduced during the electron transfer event, leading to the product water. The conditions necessary to induce this cleavage were now becoming understood. The insight developed from the mechanistic studies was used to synthesize new oxygen reduction catalysts developed from nanostructured ensembles of metal ions and polymer. Studies directed at stabilizing the metal ions in the polymeric matrix in acid solution at high potentials and at increasing the activity of the catalyst are presented. This is an abstract of a paper presented at the 231st ACS National Meeting (Atlanta, GA 3/26-30/2006).