In situ x-ray absorption studies of nanoparticles of Pt and Pt alloys
- Brookhaven National Lab., Upton, NY (United States)
Carbon supported Pt and Pt alloy nanoparticles are used as electrocatalysts for fuel cells. Alloying of Pt with first row transition elements increases the kinetics of oxygen reduction and alloying with Ru increases the activity for methanol oxidation. In situ x-ray absorption (XAS) is a very powerful technique for the study of these electrocatalysts. Analysis of the Pt XANES at the L{sub 2} and L{sub 2} edges gives information on the effect of alloying and electrode potential on the Pt d-band occupancy. Analysis of the EXAFS at the L{sub 2} edge gives information on the effect of alloying on the Pt-Pt bond distances. Examination of the Ru edge spectra in methanol containing electrolytes show the interaction of CO residues with RuOH species. About 50% of the Pt atoms in 20 {Angstrom} particles are surface atoms. This permits the use of transmission XAS to study the effect of adsorbates on the Pt electronic structure. The talk will present recent examples of these various uses of in situ XAS.
- OSTI ID:
- 538973
- Report Number(s):
- CONF-960807--
- Country of Publication:
- United States
- Language:
- English
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