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Electronic Modulation of Flexible Ether Oxygen-Based Covalent Organic Frameworks for Efficient Oxygen Reduction
Xuewen Li1, Tianyu Wang1, Lingfeng Wang1
1State Key Laboratory of Fluid Power and Mechatronic System, School of Mechanical Engineering, Zhejiang University, Hangzhou, China.
Advanced Materials (Deerfield Beach, Fla.)
|July 10, 2026
Summary
Flexible ether oxygen-based covalent organic frameworks (EO-COFs) with triazine units boost metal-free oxygen reduction reaction (ORR) electrocatalysis by enhancing charge transfer and pore adaptability. Optimized EO-COFs show high activity for energy conversion.
Area of Science:
- Materials Science
- Electrochemistry
- Catalysis
Background:
- Ether oxygen-based covalent organic frameworks (EO-COFs) offer adaptable pore microenvironments for electrochemical energy conversion.
- Efficient oxygen reduction reaction (ORR) catalysis requires accessible pores and facilitated charge transfer, which are challenging to optimize simultaneously.
Purpose of the Study:
- To synthesize novel EO-COFs incorporating electron-withdrawing triazine units to improve metal-free ORR activity.
- To investigate the role of triazine units in enhancing charge transfer and modulating electronic states.
- To explore the contribution of ether-oxygen moieties to pore adaptability and mass transport.
Main Methods:
- Synthesis of two new EO-COFs with triazine units.
- Electrochemical characterization of ORR activity, including half-wave potential and turnover frequency.
- Theoretical calculations and in-situ spectroscopy to analyze catalytic mechanisms.
Main Results:
- The optimized THD-TOT-COF demonstrated a high half-wave potential of 0.77 V and a turnover frequency of 0.0021 s⁻¹.
- Incorporation of triazine units enhanced charge-transfer capability and modulated electronic states.
- Ether-oxygen moieties facilitated mass transport and pore adaptability.
Conclusions:
- The enhanced ORR activity is attributed to facilitated formation of *OOH and *OH intermediates on triazine ring carbon atoms.
- A rational strategy for designing metal-free COF electrocatalysts involves coupling electronic-state modulation with flexible ether-oxygen frameworks.
- This approach offers a promising pathway for developing advanced electrocatalysts for energy conversion technologies.
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