S-doped Fe-N-C as Catalysts for Highly Reactive Oxygen Reduction Reactions

In this paper,a series of S-doped Fe-N-C catalysts were prepared by introducing Fe(NO3)(3)center dot 9H(2)O and KSCN in a methanol-water two-solvent system using microwave heating and high-temperature pyrolysis techniques with ZIF-8 as the precursor. The results were analyzed by several characterization means such as X-ray powder diffraction, scanning transmission electron microscopy, and nitrogen adsorption and desorption tests. The results indicated that the reasonable introduction of both Fe and S resulted in Fe3C/Fe-SAS@SNC catalysts with obvious graded porous structure and specific surface area of 673 m(2)/g, which exhibited excellent catalytic performance for oxygen reduction in both acid and alkaline electrolytes. In 0.1 mol/L KOH, the half-wave potential of the Fe3C/Fe-SAS@SNC was 0.880 V(vs. RHE), which is higher than that of commercial Pt/C catalysts, and exhibited better stability than commercial Pt/C. In addition, the Fe3C/Fe-SAS@SNC electrocatalytic oxygen reduction performance in 0.5 mol/L H2SO4 is similarly comparable to that of commercial Pt/C catalysts.