Covalent triazine framework anchored with atomically dispersed iron as an efficient catalyst for advanced oxygen reduction

Developing non-precious metal electrocatalysts with high-performance is an urgent need for market entry of proton exchange membrane fuel cells (PEMFCs). Transition metal-nitrogen-carbon catalysts are suggested as efficient oxygen reduction reaction (ORR) electrocatalysts in PEMFCs. However, uncontrollable agglomeration or inhomogeneous microstructure are often generated during the thermolysis of metal/nitrogen/carbon-containing precursors, which results in incomplete active site exposure and inferior mass transport. In this study, a facile step-wise polymerization, subsequent pyrolysis method and then with NH3 activation is explored to construct highly efficient Fe modified all-triazine C3N3 framework for cathodic reaction of fuel cells. Due to its high specific surface area (641 m(2) g(-1)), uniform distribution of active species, micro/mesoporous structure, conductive network and high pyridinic N and graphitic N content, the as-made Fe-C3N3-750-NH3 catalyst delivers atomic sized Fe species, dominant four-electron pathway, attractive ORR performance and good stability relative to commercial Pt/C electrocatalyst. Inexpensive raw materials and facile preparation combined with superior electrocatalytic performance make Fe-C3N3-750-NH3 a promising ORR catalyst, opening new avenues for application of nanostructured polymers in fuel cells.