ASAXS STUDIES OF CARBON-SUPPORTED ELECTROCATALYSTS

Anomalous small angle scattering (ASAXS) studies were performed on carbon supported Pt, Ph and PtRh catalysts. Anomalous scattering was used to vary the atomic form factors of the metal content. This allows a clear separation of the partial scattering cross sections from the porosity in the carbon support and from the metal crystallites with dimensions of about 1.5 nm. From the results of a set of differently prepared samples with catalyst particles in the form of pure Pt or alloyed PtRh and in the form of mixed Pt and Rh particles it is concluded that future ASAXS studies on fuel cell electrocatalysts, e.g. may be a very versatile tool to study the resistance against sintering or leaching-out processes.