In situ x-ray probing reveals the importance of surface platinum oxide formation in fuel cell catalysis
2011 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 13, no 1, 262-266 p.Article in journal (Refereed) Published
In situ X-ray absorption spectroscopy (XAS) at the Pt L3 edge is a useful probe for Pt–O interactions at polymer electrolyte membrane fuel cell (PEMFC) cathodes. We show that XAS using the high energy resolution fluorescence detection (HERFD) mode, applied to a well-defined monolayer Pt/Rh(111) sample where the bulk penetrating hard X-rays probe only surface Pt atoms, provides a unique sensitivity to structure and chemical bonding at the Pt-electrolyte interface. Ab initio multiple-scattering calculations using the FEFF code and complementary extended X-ray absorption fine structure (EXAFS) results indicate that the commonly observed large increase of the white-line at high electrochemical potentials on PEMFC cathodes originates from platinum oxide formation, whereas previously proposed chemisorbed oxygen-containing species merely give rise to subtle spectral changes.
Place, publisher, year, edition, pages
2011. Vol. 13, no 1, 262-266 p.
Research subject Quantum Chemistry
IdentifiersURN: urn:nbn:se:su:diva-47116DOI: 10.1039/c0cp01434fISI: 000285099800030OAI: oai:DiVA.org:su-47116DiVA: diva2:373039