Metal- and non-metal-incorporated vitamin B12 on graphene as a bio-derived electrocatalyst for the high-performance oxygen reduction reaction in acidic media

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.

Automated summary

This study introduces a novel strategy that uses vitamin B12 as a bioinspired resource to enhance the efficiency of the oxygen reduction reaction. The researchers successfully tailored the chemical structure of vitamin B12 on a graphene substrate, resulting in catalysts with various active sites. The developed catalysts exhibit excellent electrocatalytic performance for the oxygen reduction reaction and outperform commercial platinum catalysts in terms of durability and methanol tolerance.