Lewis doping strategy to synthesize Fe–N–C catalysts with high density of available active sites for oxygen reduction reactions

In recent years, non-noble metal catalysts such as Fe–N–C have received a lot of interest due to their excellent oxygen reduction (ORR) activity. However, the active sites of Fe–N–C still need to be further improved. Here, by adopting Lewis doping and double nitrogen source strategies to increase the density of accessible active sites, the catalyst exhibits excellent ORR activity. The ORR half-wave potential (E1/2) in 0.1 mol/L KOH solution can reach 0.92 V (vs. RHE), and the maximum power density of the Zn–air battery with Fe–N–C@MA-950 as the air electrode can reach 220 mW cm−2. The strategies provide a novel approach to the design of carbon-based catalysts for efficient energy conversion.