An investigation of CeO2: Local structures of doped Ag2+ and oxidation of adsorbed CO.

Based on the perturbation formulas of the spin Hamiltonian parameters (i.e., g factors and hyperfine structure constants A), the electron paramagnetic resonance (EPR) spectra (labeled as: signals a, b and c) are comprehensively investigated, from which the local environments of three different doped Ag2+ sites can be obtained and are characterized by coordinated and electronic structures. Meanwhile, the adsorption properties of CO, CO 2 and O 2 , as well as the catalytic behaviors of CO, are simultaneously verified, which are conducted by comparing the adsorption energy ∆ H , the reaction barrier ∆E of pure and the Ag doped CeO 2 surface (111). In addition, the micro-mechanism and role of doped Ag2+ in CeO 2 are explored from the interactions between the central Ag2+ and ligand oxygen ions, which are represented as covalence factor N and partial density of states (PDOS). [Display omitted] • Signals a, b and c for CeO 2 :Ag2+ is calculated by perturbation formulas. • Increase ∆H reflects positive role of doped Ag2+ for adsorbing CO molecule. • Doped Ag2+ reduce the activation energy for the oxidation process of CO. [ABSTRACT FROM AUTHOR]