Enhanced Oxygen Reduction on Hemin-Derived Fe–N Codoped Hierarchically Porous Carbon for Proton Exchange Membrane Fuel Cells

Although Pt-based catalysts demonstrate superior activity for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs), their exorbitant cost and scarcity hinder large-scale commercialization. Therefore, it is crucial to develop inexpensive and high-performance ORR catalysts to replace Pt-based catalysts. Herein, Fe–N codoped hierarchically ordered porous carbon catalysts (Fe–N–HOPC) are fabricated using Hemin as a precursor and three-dimensionally ordered SiO2 nanoparticles as a hard template. The incorporation of the hard template not only increases the specific surface area of the catalyst (124.8 m2 g–1) but also effectively prevents the formation of agglomerated Fe nanoparticles during the carbonization process. The as-fabricated Fe–N–HOPC exhibits excellent ORR catalytic activity under acidic conditions with a half-wave potential (E1/2) of 0.74 V, high selectivity of nearly four-electron transfer, and appreciable stability. As a cathode catalyst in a PEMFC, a peak power density of 405.3 mW cm–2 is delivered and a current density retention of 93.4% after 10 h of operation is achieved. This work provides a facile template-assisted method for designing and tuning of highly active Fe–N–C nonprecious metal catalysts toward practical ORR in PEMFC.