at Google ScholarTitle data
Roth, Christina ; Benker, Nathalie ; Mazurek, Marian ; Scheiba, Frieder ; Fuess, Hartmut:
Pt-Ru fuel cell catalysts subjected to H₂, CO, N₂ and air atmosphere : An X-ray absorption study.
In: Applied Catalysis A: General.
Vol. 319
(2007)
.
- pp. 81-90.
ISSN 1873-3875
DOI: https://doi.org/10.1016/j.apcata.2006.11.018
Abstract in another language
In situ X-ray absorption spectroscopy (XAS) measurements were carried out on commercial carbon-supported Pt, Ru and Pt-Ru alloy electrocatalysts as well as a Pt/Ru mixture electrocatalyst in a specifically designed reactor/furnace set-up at the Pt L3 and the Ru K edge. The catalysts were heated to 100 °C and subjected to different atmospheres - 5% H2/N2, 5% CO/N2, N2, air - of interest for fuel cell operation. X-ray absorption spectroscopy was used to follow changes in the catalyst structure, most importantly particle growth, oxidation, and (de-)alloying. Alloying is observed to be advantageous, as it decreases particle growth and oxidation tendency in the catalysts. Initially, all electrocatalysts contained large amounts of the respective oxides, as indicated by pronounced white-line intensities in the XANES spectra, whereas the catalysts were reduced to the metallic state upon exposure to hydrogen. In CO atmosphere, however, ruthenium oxides remain stable, depending on the Pt to Ru site distribution: it is assumed that Pt in contact with Ru acts as a "catalyst" for the reduction of ruthenium oxides and strengthens the Ru?CO bond favouring it over Ru-O (ligand effect). Consequently, the share of ruthenium oxides in the Pt-Ru alloy decreases in 5% CO/N2, whereas for the Pt/Ru mixture and the pure Ru it does not change significantly.
Further data
| Item Type: | Article in a journal |
|---|---|
| Refereed: | Yes |
| Keywords: | Electrocatalysts; Fuel cell; Heat-treatment; In situ; Pt; Pt-Ru; X-ray absorption spectroscopy |
| Institutions of the University: | Faculties > Faculty of Engineering Science > Chair Electrochemical Process Engineering > Chair Electrochemical Process Engineering - Univ.-Prof. Dr. Christina Roth Faculties Faculties > Faculty of Engineering Science Faculties > Faculty of Engineering Science > Chair Electrochemical Process Engineering |
| Result of work at the UBT: | No |
| DDC Subjects: | 500 Science > 540 Chemistry 600 Technology, medicine, applied sciences > 620 Engineering |
| Date Deposited: | 23 Apr 2021 08:31 |
| Last Modified: | 28 Aug 2023 06:08 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/64902 |