EXAFS, XPS and electrochemical studies on oxygen reduction catalysts obtained by heat treatment of iron phenanthroline complexes supported on high surface area carbon black

Oxygen reduction catalysts have been prepared on the basis of heat-treated, carbon supported iron phenanthroline complexes. The activity of the catalyst towards oxygen reduction depends on the surface area of the carbon used in the synthesis. It is higher than the activity of other alternative oxygen reduction catalysts based on ruthenium. Related to the amount of metal, the activity is comparable to that of the state-of-the-art oxygen reduction catalyst, platinum supported onto carbon. EXAFS measurements indicate that the structure of the active centre of the catalyst consists of an iron ion, which is coordinated to four nitrogen atoms. No crystalline particles can be found in the catalyst using TEM.