Fundamental understanding of nitrogen in biomass electrocatalysts for oxygen reduction and zinc-air batteries

Exploring high -efficiency catalysts for oxygen reduction reactions (ORRs) is essential for the development of large-scale applications of fuel cell and metal -air batteries technology. The as -prepared Fe -NC -800 via polymerization -pyrolysis strategy exhibited superior ORR activity with onset potential of 1.030 V vs. reversible hydrogen electrode (RHE) and half -wave potential of 0.908 V vs. RHE, which is higher than that of the Pt/C catalyst and most of other Fe -based catalysts. The different d -band center values can be attributed to the influence of different N -doped carbon, leading to the adjustment in the ORR activity. In addition, Fe -NC -800 -based Zn-air battery showed better electrochemical performance with a high discharge specific capacity of 806 mA h g-1 and a high -power density of 220 mW cm -2 than that of the Pt/C-based battery. Therefore, the biomass Fe -NC -800 catalyst may become a promising substitute for Pt/C catalysts in energy storage and conversion devices.