Oxygen Adsorption on PdPt/Au(111) - DFT Calculations

Being a slow reaction, oxygen reduction is a limiting factor for fuel cell efficiency, prompting the development of new materials capable of promoting this process. Alloy formation can improve the geometry and electronic properties of surfaces, facilitating catalysis of the oxygen reduction reaction when these materials are employed in fuel cell cathodes. This article reports the use of density functional theory to investigate oxygen adsorption onto a PdPt/Au(111) surface. The hollow fcc site is predicted as the most favorable to oxygen binding to the surface, with a binding energy of about -2.31 eV. As the number of species on the surface is increased, the binding energy tends to rise, owing to lateral repulsion between oxygen atoms. We found an energy barrier of 0.74 eV for the dissociation of the oxygen molecule on this surface.