Density Functional Study on the Structures and Adsorption Properties of PtAgn (n = 1–16) Clusters

Abstract

The structures and properties of PtAg_n (n = 1–16) clusters have been studied by density functional theory (DFT). The Tpssh/def2-TZVP method is chosen in this work. Calculations reveal that the structures of PtAg_n (n = 1–16) clusters are planar structures when n = 1–3, while they present three-dimensional structures when n = 4–16. The coordination number of the Pt atom in PtAg_n (n = 1–16) clusters are in the range of 1–11. Pt atoms in PtAg_n (n = 1–16) clusters prefer to locate in the centers of the structures. The electronic structures are compared with available experimental and theoretical data. The stability analysis manifests that the clusters have odd-even stability properties. The study of catalytic properties on PtAg_n (n = 1–16) clusters perform similar interactions with one CO molecule. The Pt atom favors interacting with the carbon terminal of the CO molecule. According to the thermodynamic property study, the adsorption reactions of PtAg_n (n = 1–16) and CO are all spontaneous. The stability of PtAg_nCO (n = 1–16) clusters present odd-even properties. The projected density of states (PDOS) study reveals that the orbital hybridization phenomenon is present between the Pt and C atoms in the PtAg₆CO cluster.