Rational design and synthesis of hollow Fe-N/C electrocatalysts for enhanced oxygen reduction reaction.

Herein, we report a one-step synthesis of a hollow Fe-N/C catalyst via a hard-templating strategy, in which FeNx sites are well dispersed on the carbon sphere. In particular, we found an optimal iron ratio on the catalyst surface for an enhanced alkaline oxygen reduction reaction (ORR). The catalyst with a high specific surface area of 311.71 m2 g-1 exposes abundant electroactive sites that facilitate the adsorption of oxygen intermediates, thus exhibiting superior ORR activity in alkaline solution.