An Unsaturated Bond Strategy to Regulate Active Centers of Metal‐Free Covalent Organic Frameworks for Efficient Oxygen Reduction. (17th October 2022)

• Record Type: Journal Article
• Authors: Yan, Xiangyu; Wang, Bingbing; Ren, Jun; Long, Xiaojing; Yang, Dongjiang
• Is Part Of: Angewandte Chemie. Volume 134:Number 46(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-10-17
• Subjects: Active Centers -- Covalent Organic Frameworks -- Electrocatalysis -- Oxygen Reduction Reaction -- Unsaturated Bonds; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202209583
• Languages: English
• ISSNs: 0044-8249

Abstract

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. Abstract : A novel strategy to modulate the charge distribution of active centers of organic catalysts by using unsaturated bonds (UBs) is reported. The UBs can produce para ‐activation, identifying the para C=N group as active centers. The effect of UBs decoration on adsorption property of the catalysts is disclosed.