Abstract

The development of efficient oxygen reduction reaction (ORR) catalysts is essential for the commercialization of fuel cells. Graphene can significantly improve the ORR performance of platinum-based catalysts, but the fundamental mechanism of such a promotional effect is unclear. Herein, the reaction processes of the ORR on graphene supported PtFe nanoalloys have been investigated using in situ enhanced Raman spectroscopy through the fabrication of graphene-isolated satellite nanostructures. The *OOH and *OH intermediates are identified and confirmed using isotopic substitution during the ORR on PtFe with or without graphene, respectively. Density functional theory (DFT) calculations and X-ray photoelectron spectroscopy further demonstrate such a difference result from the electronic effect of graphene. The graphene electronic effect promotes the formation of *OOH and the further conversion of *OH to the final product water, thus leading to the improved ORR performance of PtFe supported on graphene. This work sheds light on the molecular mechanism of the promotional role of graphene on the ORR and provides theoretical guidance for the rational design of ORR catalysts.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.