In-situ XAFS characterization of PtPd nanoparticles synthesized by galvanic replacement

Platinum-palladium nanoparticles are synthesized and characterized with regard to their application in fuel cells due to their high (electro)catalytic activity. Different preparation times are applied leading to different structures, from Pd cubic to core-shell PtPd concave, and different chemical compositions. The resulting particles are studied via TEM and in-situ XAFS measurements. The latter allows the investigation of the oxygen reduction reaction following the variations with varying applied potentials by analysis using ITFA and the creation of a two-component system that consists of metallic Pt-Pd and the related oxide. With the used model, the different concentrations of the oxide are linked to the consecutive chemical steps of the oxygen reduction reaction.
Finally, the catalytic activity of the particles is determined via linear scanning voltammetry and reveals a dependence on the shape and the composition of the particles.