Quantum-Chemical Modeling of Ag/CeO2 Nanoscale Catalysts.

The authors summarize results from calculations using the density functional theory for atoms and small silver clusters on surfaces of nanostructured cerium(IV) oxide, along with the adsorption and transformations of O₂ and CO molecules on these systems. Stoichiometric Ce₂₁O₄₂, which has {100} and {111} nanofacets with adsorption centers containing four and three oxygen atoms, is used to model surfaces of cerium oxide. It is shown the O₄-center is a center of the selective adsorption of metal atoms. A silver atom on an O₃‑center is less stable but it shows a greater ability to activate an O₂ molecule. Results from calculations on the {100} and {111} faces of Ce₂₁O₄₂ nanoparticles are compared to data for infinite CeO₂(100) and CeO₂(111) surfaces. The efficiency of Ag/Ce₂₁O₄₂ atomic complexes is shown in the oxidation of carbon monoxide. Keywords: cerium oxide silver adsorption CO oxidation density functional theory [ABSTRACT FROM AUTHOR]