Boosting Oxygen Reduction Catalysis with Fe–N4 Sites Decorated Porous Carbons toward Fuel Cells

It is highly desired but remains a great challenge to develop nonprecious metal single-atom catalysts to supersede the Pt-based material for oxygen reduction reaction (ORR). Herein, we report a porous nitrogen-doped carbon matrix catalyst with 3.5 wt % single Fe atoms (Fe SAs/N–C) through a versatile molecules-confined pyrolysis strategy. In 0.1 M KOH condition, the Fe SAs/N–C catalyst possesses a half-wave potential of 0.91 V vs RHE. In a more challenging acidic solution, Fe SAs/N–C catalyst also offers good ORR activity, comparable with the commercial Pt/C. Impressively, Fe SAs/N–C shows extremely high stability both in alkaline and acidic media. In addition, this Fe SAs/N–C-derived Zn–air battery and proton exchange membrane fuel cells (PEMFCs) exhibit high performance. This work opens an avenue for designing and preparing single-atom catalysts.