Towards a Multiscale Modeling Methodology for the Prediction of the Electro-Activity of PEM Fuel Cell Catalysts
Résumé
In this study, density functional theory (DFT) calculations are presented for molecular and atomic oxygen adsorption on the Pt(111) surface at low coverage. The final goal is the atomistic description of oxygen dissociation kinetics in order to feed a multiscale kinetic model which simulates the Polymer Electrolyte Membrane Fuel Cell (PEMFC) electrochemical behavior. For molecular oxygen, the most favorable adsorption structure is top-top and shows an adsorption energy of -0.80 eV in agreement with previous studies. For atomic adsorption, only the threefold fcc and hcp hollow sites are stable at this coverage (-1.22 eV and -0.85 eV, respectively), in contrast with previous results.