Xu, T., Zhou, H., Zhang, X., Herng, T. S., Ding, J., Chi, C., & Zhu, J. (2025). Covalent Organic Frameworks with Carbon‐Centered Radical Sites for Promoting the 4e− Oxygen Reduction Reaction. Angewandte Chemie International Edition, 64(13). Portico. https://doi.org/10.1002/anie.202424449
Abstract:
Radical covalent organic frameworks (RCOFs) have demonstrated significant potential in redox catalysis and energy conversion applications. However, the synthesis of stable RCOFs with well‐defined neutral carbon radical centers is challenging due to the inherent radical instability, limited synthetic methods and characterization difficulties. Building upon the understanding of stable carbon radicals and structural modulations for preparing crystalline COFs, herein we report the synthesis of a crystalline carbon‐centered RCOF through a facile post‐oxidation process. Moreover, the RCOF demonstrated outstanding catalytic activity in the 4e− oxygen reduction reaction (ORR) with a half‐wave potential of 0.82 V (vs. RHE) and electron transfer number of 3.98, among the highest in reported COF‐based electrocatalysts. The promoted 4e− and suppressed 2e− ORR pathway (99.5 % vs. 0.5 %) can be attributed to facilitated reaction initiation and smoother transition steps at the carbon radical sites, which is practically beneficial for minimizing peroxide formation, thus contributing to safer and more sustainable fuel cell and metal‐air battery applications. Overall, our study not only provided a facile strategy for preparing stable RCOFs with well‐defined neutral carbon radical centers but also demonstrated their capability to fine‐tune the redox catalytic activity of COF materials, which could be potentially useful in electrocatalysis and energy conversion applications.
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Funding Info:
This research / project is supported by the Agency for Science, Technology and Research - Manufacturing, Trade, and Connectivity Young Individual Research Grant
Grant Reference no. : M23M7c0118, M23M7c0117
This research / project is supported by the Agency for Science, Technology and Research - Career Development Fund
Grant Reference no. : C233312013
This research / project is supported by the Ministry of Education, Singapore - Academic Research Fund Tier 2
Grant Reference no. : MOET2EP10222-0008
This research / project is supported by the Ministry of Education, Singapore - Academic Research Fund Tier 1
Grant Reference no. : A-8000992-00-00
Description:
This is the peer reviewed version of the following article: Xu, T., Zhou, H., Zhang, X., Herng, T. S., Ding, J., Chi, C., & Zhu, J. (2025). Covalent Organic Frameworks with Carbon‐Centered Radical Sites for Promoting the 4e− Oxygen Reduction Reaction. Angewandte Chemie International Edition, 64(13). Portico, which has been published in final form at https://doi.org/10.1002/anie.202424449. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.