Iron Carbide Nanoparticles Encapsulated in Mesoporous Fe‐N‐Doped Carbon Nanofibers for Efficient Electrocatalysis.

A new catalyst for the oxygen reduction reaction in fuel cells and metal—air batteries is prepared from aqueous solutions of carbonaceous nanofibers, pyrrole, and FeCl3 (room temperature, 4 h, followed by pyrolysis under flowing N2).