CNTs@Fe-C-C core-shell nanostructures as active electrocatalyst for oxygen reduction

The development of non-precious metal catalysts for oxygen reduction reactions (ORRs) is of extreme importance for the construction of efficient H-2/O-2 polymer electrolyte membrane fuel cells (PEMFCs), one of the most promising clean energy technologies. Herein, we report the fabrication of core-shell structured CNTs@Fe-N-C composites with a Fe-N-C shell closely wrapped around a core of CNTs (carbon nanotubes) as efficient catalysts for ORR. CNTs@Fe-N-C composites afford comparable activity to commercial Pt/C catalysts with a loading of 20 mu g Pt cm(-2) towards ORR in alkaline media. The results of XRD, TEM. XPS and Fe-57 MOssbauer characterizations suggest that the high ORR activity of CNTs@.FeN-C composites are mainly attributed to the combined advantages of the unique core-shell nanostructure allowing close contact between Fe-N-C and CNTs, uniformly distributed FeN4/C species, and the presence of pyridine and graphitic nitrogen.