Designing Co–N/C cathode catalysts with dense atomic cobalt sites for enhanced PEMFC performance
Author(s)
Type
Journal Article
Abstract
Metal-nitrogen/carbon (M-N/C) catalysts, particularly those incorporating Fe, Co, or Mn, are among the most promising non-platinum group catalysts for the acidic oxygen reduction reaction (ORR) in fuel cells. This study reports a Co-N/C catalyst featuring high (3 wt%) cobalt content exclusively present as atomic sites. Extended X-ray absorption fine structure analysis confirms a tetrapyridinic Co-N4 coordination environment in the optimized (3.0)Co-N/CΔ catalyst. The high cobalt loading leads to a significant density of electrochemically accessible active sites, 3.58 × 1019 sites g−1, quantified via the nitrite stripping method. The catalyst demonstrates excellent ORR activity in a rotating ring-disk electrode setup, achieving a half-wave potential (E1/2) of 0.76 V at a low loading of 0.2 mg cm−2 and a mass activity of 3.5 A g−1 at 0.80 VRHE. Single-cell hydrogen-oxygen PEMFC tests achieve a peak power density exceeding 1.3 W cm−2 (iR-corrected). Under hydrogen-air condition, the catalyst delivers 0.54 A cm−2 at 0.60 V (0.39 W cm−2). Despite the intrinsically higher turnover frequency of Fe-based sites, the optimized (3.0)Co-N/CΔ catalyst achieves similar fuel cell performance to that of Fe-N/C, highlighting the critical role of site density in overall activity.
Date Issued
2026-01-09
Date Acceptance
2025-10-01
Citation
Advanced Science, 2026, 13 (2)
ISSN
2198-3844
Publisher
Wiley
Journal / Book Title
Advanced Science
Volume
13
Issue
2
Copyright Statement
© 2025 The Author(s). Advanced Science published by Wiley-VCH GmbH This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/41090653
Subjects
non‐precious single atom catalyst
oxygen reduction reaction
proton‐exchange membrane fuel cell
Publication Status
Published
Coverage Spatial
Germany
Article Number
e16060
Date Publish Online
2025-10-15