Novel dual templating approach for preparation of highly active Fe-N-C electrocatalyst for oxygen reduction

A highly active, stable Fe-N-C electrocatalyst with unique 3D porous graphene “nano-stack” morphology is synthesized using a novel, facile and a direct process that involves a sodium salt templating of a small organic molecule benzimidazole carboxylic acid. We synthesize different combinations of the precursor with sodium salt templates and silica sacrificial support method, followed by their pyrolysis to generate Fe-N-C catalysts. The oxygen reduction reaction catalytic performance of such benzimidazole derived catalysts is studied in the alkaline media using rotating ring disk electrode and in alkaline exchange membrane fuel cell. The electrocatalytic performance of the best catalyst shows an improvement over the commercial Pt/C catalyst in the Rotating Ring-Disk Electrode tests along with excellent stability (as performed under the Department of Energy- Durability Working Group protocols). This work offers intriguing future avenues to the direct synthesis of Fe-N-C catalysts from tuning small molecule organic precursors for high temperature pyrolysis.