Nanostructured Cementite/Ferrous Sulfide Encapsulated Carbon with Heteroatoms for Oxygen Reduction in Alkaline Environment

Nonprecious metal catalysts of the oxygen reduction reaction (ORR) are highly preferred in anion exchange membrane fuel cells (AEMFCs) because of the high stability and low cost. Here, a novel pyrolyzed poly(3,4-ethylene dioxythiophene) hydrate (PEDOT)-Prussian blue (PB) catalyst (FeCN-S) for the ORR in an AEMFC cathode demonstrated high catalytic performance. After pyrolysis at 800 °C, the templated PB-PEDOT formed the nanostructured Fe3C/FeS encapsulated carbon with heteroatom contribution, which exhibited optimized ORR activity with a direct four-electron transfer pathway for AEMFC applications. This improvement in activity is attributed to the specific structure, the heteroatom contribution, and the coordination structure.