Rational Design of Fe1-xS/Fe3O4/Nitrogen and Sulfur-Doped Porous Carbon with Enhanced Oxygen Reduction Reaction Catalytic Activity

In this paper, the rational design of Fe-N-, Fe-S-, and Fe-N-S-based model catalysts for oxygen reduction reaction (ORR), developed using task-specific hypercrosslinked polymers as precursors is presented. Based on the model catalysts, atom-induced differences in ORR performance are carefully examined. In the S-doped carbons, Fe1-xS forms the metal nanoparticles, while the N sourced together with FeCl3 ensures the uniform distribution of Fe3O4. Obtained results indicate that N/Fe3O4 acts as the higher catalytic active site, whereas the S/Fe1-xS deteriorates the ORR catalytic activity. However, due to the synergistic effect between Fe1-xS /Fe3O4 and N, the S-doped carbons can substantially enhance the ORR performance. Hence, this work provides guidance for the efficient design of Fe-N-S-based catalysts for ORR.