Electron Spin Catalysis with Graphene Belts. Issue 10 (31st January 2023)

• Record Type: Journal Article
• Authors: Tian, Yulan; Cao, Huaqiang; Yang, Haijun; Yao, Wenqing; Wang, Jiaou; Qiao, Zirui; Cheetham, Anthony K.
• Is Part Of: Angewandte Chemie international edition. Volume 62:Issue 10(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-31
• Subjects: Electron Spin Resonance -- Graphene Belts -- Mechanism -- Radical Coupling Reaction -- Spin Catalysis; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202215295
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Here, we report kinetic studies using electron spin resonance spectroscopy on spin catalysis reactions caused by using graphene belts which were synthesized by a radical coupling method. The results show that σ‐type free radical species provide the dominant sites for catalytic activity through the spin‐spin interaction, although there are some other influencing factors. The spin catalysis mechanism can be applied both in the oxygen reduction reaction (ORR) and in organic synthesis. The graphene belt spin catalyst shows excellent performance with a high ORR half‐wave potential of 0.81 V and long‐term stability with almost no loss of activity after 50 000 cycles in alkaline media. It also shows excellent performance in a benzylamine coupling with molecular oxygen to generate the corresponding imine at an average conversion of ≈97.7 % and an average yield of ≈97.9 %. This work opens up a new research direction for understanding aerobic processes in the field of spin catalysis. Abstract : Graphene belts with high electron spin concentrations, which were synthesized by C (sp 2 )−C (sp 2 ) radical coupling, act as aerobic spin catalysts for both the oxygen reduction reaction (ORR) and a benzylamine coupling with molecular oxygen to generate the corresponding imine; the catalytic mechanism has been studied by electron spin resonance spectroscopy.