Roth, Christina ; Benker, Nathalie ; Buhrmester, Thorsten ; Mazurek, Marian ; Loster, Matthias ; Fuess, Hartmut ; Koningsberger, Diederik C. ; Ramaker, David E. (2005)
Determination of O[H] and CO Coverage and Adsorption Sites on PtRu Electrodes in an Operating PEM Fuel Cell.
In: Journal of the American Chemical Society, 127 (42)
doi: 10.1021/ja050139f
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
A special in situ PEM fuel cell has been developed to allow X-ray absorption measurements during real fuel cell operation. Variations in both the coverage of O[H] (O[H] indicates O and/or OH) and CO (applying a novel ΔμL3 = μL3(V) − μL3(ref) difference technique), as well as in the geometric (EXAFS) and electronic (atomic XAFS) structure of the anode catalyst, are monitored as a function of the current. In hydrogen, the NPt-Ru coordination number increases much slower than the NPt-Pt with increasing current, indicating a more reluctant reduction of the surface Pt atoms near the hydrous Ru oxide islands. In methanol, both O[H] and CO adsorption are separately visible with the Δμ technique and reveal a drop in CO and an increase in OH coverage in the range of 65−90 mA/cm2. With increasing OH coverage, the Pt−O coordination number and the AXAFS intensity increase. The data allow the direct observation of the preignition and ignition regions for OH formation and CO oxidation, during the methanol fuel cell operation. It can be concluded that both a bifunctional mechanism and an electronic ligand effect are active in CO oxidation from a PtRu surface in a PEM fuel cell.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2005 |
| Autor(en): | Roth, Christina ; Benker, Nathalie ; Buhrmester, Thorsten ; Mazurek, Marian ; Loster, Matthias ; Fuess, Hartmut ; Koningsberger, Diederik C. ; Ramaker, David E. |
| Art des Eintrags: | Bibliographie |
| Titel: | Determination of O[H] and CO Coverage and Adsorption Sites on PtRu Electrodes in an Operating PEM Fuel Cell |
| Sprache: | Englisch |
| Publikationsjahr: | 26 Oktober 2005 |
| Verlag: | ACS Publications |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of the American Chemical Society |
| Jahrgang/Volume einer Zeitschrift: | 127 |
| (Heft-)Nummer: | 42 |
| DOI: | 10.1021/ja050139f |
| Kurzbeschreibung (Abstract): | A special in situ PEM fuel cell has been developed to allow X-ray absorption measurements during real fuel cell operation. Variations in both the coverage of O[H] (O[H] indicates O and/or OH) and CO (applying a novel ΔμL3 = μL3(V) − μL3(ref) difference technique), as well as in the geometric (EXAFS) and electronic (atomic XAFS) structure of the anode catalyst, are monitored as a function of the current. In hydrogen, the NPt-Ru coordination number increases much slower than the NPt-Pt with increasing current, indicating a more reluctant reduction of the surface Pt atoms near the hydrous Ru oxide islands. In methanol, both O[H] and CO adsorption are separately visible with the Δμ technique and reveal a drop in CO and an increase in OH coverage in the range of 65−90 mA/cm2. With increasing OH coverage, the Pt−O coordination number and the AXAFS intensity increase. The data allow the direct observation of the preignition and ignition regions for OH formation and CO oxidation, during the methanol fuel cell operation. It can be concluded that both a bifunctional mechanism and an electronic ligand effect are active in CO oxidation from a PtRu surface in a PEM fuel cell. |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Erneuerbare Energien 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Strukturforschung 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften |
| Hinterlegungsdatum: | 20 Feb 2013 09:47 |
| Letzte Änderung: | 05 Mär 2013 10:05 |
| PPN: | |
| Sponsoren: | Financial support of the Deutsche Forschungsgemeinschaft is gratefully acknowledged. |
| Export: | |
| Suche nach Titel in: | TUfind oder in Google |
 |
Frage zum Eintrag |
Optionen (nur für Redakteure)
 |
Redaktionelle Details anzeigen |
Drucken
Impressum