Volume 134, Issue 46 e202209583
Forschungsartikel

An Unsaturated Bond Strategy to Regulate Active Centers of Metal-Free Covalent Organic Frameworks for Efficient Oxygen Reduction

Xiangyu Yan

Xiangyu Yan

State Key Laboratory of Bio-fibers and Eco-textiles, Collaborative Innovation Center of Shandong Marine Biobased Fibers and Ecological textiles, Institute of Marine Biobased Materials, College of Materials Science and Engineering, School of Environmental Science and Engineering, Qingdao University, Qingdao, 266071 P.R. China

These authors contributed equally to this work.

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Prof. Bingbing Wang

Prof. Bingbing Wang

State Key Laboratory of Bio-fibers and Eco-textiles, Collaborative Innovation Center of Shandong Marine Biobased Fibers and Ecological textiles, Institute of Marine Biobased Materials, College of Materials Science and Engineering, School of Environmental Science and Engineering, Qingdao University, Qingdao, 266071 P.R. China

These authors contributed equally to this work.

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Prof. Jun Ren

Prof. Jun Ren

School of Chemical Engineering and Technology, Shanxi Key Laboratory of High Performance Battery Materials and Devices, North University of China, Taiyuan, 030051 P. R. China

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Prof. Xiaojing Long

Corresponding Author

Prof. Xiaojing Long

State Key Laboratory of Bio-fibers and Eco-textiles, Collaborative Innovation Center of Shandong Marine Biobased Fibers and Ecological textiles, Institute of Marine Biobased Materials, College of Materials Science and Engineering, School of Environmental Science and Engineering, Qingdao University, Qingdao, 266071 P.R. China

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Prof. Dongjiang Yang

Corresponding Author

Prof. Dongjiang Yang

State Key Laboratory of Bio-fibers and Eco-textiles, Collaborative Innovation Center of Shandong Marine Biobased Fibers and Ecological textiles, Institute of Marine Biobased Materials, College of Materials Science and Engineering, School of Environmental Science and Engineering, Qingdao University, Qingdao, 266071 P.R. China

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First published: 21 September 2022
Citations: 4

Abstract

Unsaturated environment is the key to affect catalytic activity of the oxygen reduction reaction (ORR). Unveiling the effect of unsaturated sites toward ORR activity is of importance due to the vague unsaturated states. Reported here is a proof-of-concept strategy on the evaluation of unsaturated bonds (UBs) on adjacent carbon environment by precisely developing two metal-free vinyl-/azo-decorated covalent organic frameworks (Vinyl-COF and Azo-COF) as catalysts. The as-prepared UB-COFs exhibit good performance than the control Py-COF and comparable to the most reported carbon catalysts. Supported by theory calculations and in situ Raman spectra-electrochemistry, it is revealed that the UBs in organic catalysts can produce para-activation, identifying the para C=N groups as active centers. Importantly, the intrinsic UBs can induce local charge redistribution, and make the molecular skeleton possess high isosurface map distribution, with an efficient affinity for oxygen intermediates.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available in the Supporting Information of this article.

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