Tunable Metal-Free Imidazole-Benzimidazole Electrocatalysts for Oxygen Reduction in Aqueous Solutions
Issued Date
2023-01-01
Resource Type
ISSN
09476539
eISSN
15213765
Scopus ID
2-s2.0-85178483537
Journal Title
Chemistry - A European Journal
Rights Holder(s)
SCOPUS
Bibliographic Citation
Chemistry - A European Journal (2023)
Suggested Citation
Tanjedrew N., Thammanatpong K., Surawatanawong P., Chakthranont P., Chantarojsiri T., Unjarern T., Kiatisevi S. Tunable Metal-Free Imidazole-Benzimidazole Electrocatalysts for Oxygen Reduction in Aqueous Solutions. Chemistry - A European Journal (2023). doi:10.1002/chem.202302854 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/91392
Title
Tunable Metal-Free Imidazole-Benzimidazole Electrocatalysts for Oxygen Reduction in Aqueous Solutions
Author's Affiliation
Other Contributor(s)
Abstract
A series of metal-free imidazole-benzimidazole catalysts (ImBenz-H, ImBenz-NO2, ImBenz-OCH3) for oxygen reduction reaction (ORR) were prepared. We demonstrate that the electrocatalytic O2 reduction by ImBenz-NO2 with the electron-withdrawing group showed high selectivity toward H2O with the number of electrons transferred (n=3.7) in a neutral aqueous solution. The highest ORR selectivity toward H2O2 was achieved using ImBenz-H (n=2.4) in an alkaline solution. Electrochemical studies of reaction kinetics disclosed that the highest turnover frequencies were obtained from ImBenz-H in both neutral and alkaline aqueous solutions. The results prove that the ORR selectivity is tunable by modulating the substituent of the ImBenz catalysts. Furthermore, DFT calculations suggested that the ORR mechanism of ImBenz-H involves the electron transfer from imidazole-benzimidazole to O2 resulting in the formation of H2O2 which supports the redox active properties of the catalysts ImBenz.