Computational Study of Pt/Co Core-Shell Nanoparticles: Segregation, Adsorbates and Catalyst Activity

A computational study on Pt/Co core-shell nanoparticles, which are promising candidates in the search of more active catalysts for the oxygen reduction reaction in fuel cell technology, is presented. We study the energetics of the segregation process using density functional theory (DFT) and a 37-atom cluster model. The influence of the adsorbates CO, O and O-2 on the segregation energy is investigated. Furthermore, Norskov's model of the oxygen binding energy is used as an indicator to estimate the activity of the model system and to investigate electronic and geometric effects.