High Surface Iron/Cobalt-Containing Nitrogen-Doped Carbon Aerogels as Non-Precious Advanced Electrocatalysts for Oxygen Reduction

Nitrogen-doped carbon-based catalysts are promising candidates to substitute expensive and moderately durable platinum-based catalysts for polymer electrolyte membrane fuel cells (PEMFCs). Condensation of ionic liquids (ILs) in salt melts enables the formation of hierarchically porous nitrogen-doped carbons with very high surface areas. Here we present synthesis and the employment of high-nitrogen-doped carbon aerogels modified with iron and cobalt for the oxygen reduction reaction (ORR), the relevant half-cell reaction for all fuel cells, using rotating disk/ring-disk electrode measurements. We show favorable performances compared to the current Pt/C standard. TEM analysis of the iron composites gave an amorphous, quasi-atomic distribution of the metal, while iron/cobalt composites form very small, well-supported nanoparticles.