First-Principles investigation of Single Layer of Pt on Graphene

In this study, we present a computational research on the unique architecture of epitaxial platinum (mono/multi) layers grown on graphene (Pt_ML/GR), in simple cubic-like (SC-L) and face-centered cubic-like (FCC-L) phases on the graphene. In these architectures, Pt exhibits registry with the C-C bridge sites along the armchair and zigzag directions. Here, the detailed band structure and the partial/total densities of state (DOS) of the Pt_ML/GR architectures, with Pt in an SC-L registry, is presented. Pt atoms on graphene prefer bonding with two carbons covalently, turning C-C sp2 bond to sp3 bond, while metallic bonding prevails on the Pt atoms. First, the epitaxial geometry of Pt layers as well as inter-layer distance between graphene and Pt layer are in good agreement with the experimental observations. Second, the covalent bond character is observed between Pt and C while Pt layer attains the metallic bond character. Furthermore, as an application for electrochemical system such as fuel cells, the efficacy and the stability of Pt ML/GR catalysts under the canonical oxygen reduction reaction are presented.