▎ 摘　　要

The development of fine-tuned non-platinum group metals and their derivatives, which are high-performance, economical, and stable electrocatalysts used for the oxygen reduction reaction (ORR), is critical for the large-scale deployment of fuel cells and metal-air batteries. This study presents a novel strategy that uses vitamin B12 (VB) as a bioinspired resource for the ORR; VB was modified using metal and non-metal incorporation to boost the efficiency of the ORR. The chemical structure of VB on a graphene substrate was tailored by synergistically incorporating both iron and sulfur upon pyrolysis, yielding various active sites based on Fe-(N,S)-C and Co-(N,S)-C. The resultant catalysts, termed Fe-SVB/GR, exhibit prominent electrocatalytic performance for the ORR via a favorable 4e(-) reaction pathway. The onset and half-wave potentials of the optimized electrocatalyst were 0.90 and 0.74 V vs. reversible hydrogen electrode, respectively, which are comparable or better than those previously reported for non-platinum group catalysts. The Fe-SVB/GR electrocatalyst developed in this study outperformed a commercial Pt/C catalyst in terms of its durability and methanol tolerance. Therefore, this study introduced a novel strategy to produce bio-derived materials as non-platinum group electrocatalysts used as efficient cathode materials in energy-conversion devices. (c) 2022 Elsevier B.V. All rights reserved.