Stability of Pt Alloy High Surface Area Catalysts

Alloys of Pt with other transition metals are a promising class of fuel cell cathode catalysts. In the present work it is shown that the surface composition of high surface area Pt3Co electrocatalysts can be changed in situ by means of different electrochemical treatments. Surface segregation is det...

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Bibliographic Details
Main Authors: Hartl, Katrin G., Mayrhofer, Karl J., Arenz, Matthias
Format: Conference Proceeding
Language:English
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Summary:Alloys of Pt with other transition metals are a promising class of fuel cell cathode catalysts. In the present work it is shown that the surface composition of high surface area Pt3Co electrocatalysts can be changed in situ by means of different electrochemical treatments. Surface segregation is detected by cyclic voltammetry in base electrolyte where the Pt alloy is stable and specific peaks reflect the surface composition. During CO annealing Pt surface segregation takes place and Co atoms disappear from the surface. Contrary, by cycling in Ar saturated solution to high potentials the inverse process takes place and Co atoms re-emerge on the surface, an effect of high importance considering the stability of alloy electrocatalysts in acidic PEM fuel cells.
ISSN:1938-5862
1938-6737
DOI:10.1149/1.3210606