In situ synchrotron x-ray spectroscopy of ruthenium nanoparticles modified with selenium for an oxygen reduction reaction.
We used in situ Se K-edge X-ray spectroscopy to characterize Ru nanoparticles chemically modified with submonolayers of selenium (Se/Ru) [Cao et al. J. Electrochem. Soc. 2006, 153, A869]. X-ray powder diffraction verified that the Se/Ru catalyst had metallic Ru cores. The in situ X-ray absorption near edge structure taken at the open circuit potential showed that there were both elemental and oxidized selenium on the as-prepared Se/Ru samples. All selenium oxide was reduced to the elemental form of selenium by applying negative potentials. By applying positive potentials, selenium was subsequently reoxidized. The analysis of the extended X-ray absorption fine structure shows the appearance of selenium hydration (Se-OH{sub 2}) in a deaerated solution, which was not observed during the oxygen reduction reaction. We present evidence that Se-free Ru atoms play an important role in the ORR activity of the Se/Ru catalyst studied in this paper.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); MURI grant
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 939329
- Report Number(s):
- ANL/MSD/JA-60403; TRN: US0806754
- Journal Information:
- J. Phys. Chem. C, Vol. 111, Issue 45 ; Nov. 15, 2007
- Country of Publication:
- United States
- Language:
- ENGLISH
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