FeCo-based mesoporous carbon shells modified N-doped porous carbon spheres for oxygen reduction reaction.

FeCo-based non-noble metal electrocatalysts (NNMEs) of FeCo/MCS-NPCS was fabricated by immobilization of hemin on mesoporous carbon shells modified N-doped porous carbon spheres (MCS-NPCS). The obtained FeCo/MCS-NPCS exhibits a half-wave potential (E 1/2) of 0.851 ​V versus the reversible hydrogen electrode (vs. RHE) and a limited-diffusion current density (J L) of 5.45 ​mA ​cm−2. In addition, FeCo/MCS-NPCS shows comparable oxygen reduction reaction (ORR) performances to 20 ​wt% Pt/C in terms of E 1/2 and J L and better electrochemical properties, including the methanol tolerance and durability in alkaline solution. Such outstanding electrochemical activities of FeCo/MCS-NPCS can be ascribed to Fe and/or Co-based nitrides and carbides as well as N-doped carbon matrixes modified with mesoporous carbon shells. This research introduces a promising path to design and synthesize highly efficient FeCo–N–C electrocatalysts towards ORR. [Display omitted] • MCS-NPCS was fabricated by modifying ZIF-67 with polydopamine (PDA) and tetraethoxysilane (TEOS). • FeCo/MCS-NPCS was obtained by supporting hemin over the MCS-NPCS followed by pyrolysis and acid-leaching. • FeCo/MCS-NPCS decorated with mesoporous carbon shells are in favor of improving the ORR performance in alkaline solution. • FeCo/MCS-NPCS displays comparable ORR performance and better durability relative to commercial Pt/C in alkaline solution. [ABSTRACT FROM AUTHOR]