Fully Synthetic Approach toward Transition Metal-Nitrogen-Carbon Oxygen Reduction Electrocatalysts

We report a nonpyrolytic chemical synthesis of model iron-nitrogen-carbon electrocatalysts for oxygen reduction reaction (ORR) to elucidate the role of Fe-N centers in the catalysis mechanism. The graphene-supported and unsupported catalysts were analyzed in detail by X-ray spectroscopy techniques. The electrochemical analysis was performed by linear sweep voltammetry and square wave voltammetry in 0.5 M H2SO4 and 0.1 M KOH electrolytes. In this article, with the use of model catalysts, we manifest and confirm the difference in the specific role of Fe-N active sites toward ORR in acidic and alkaline environments.