Quantum-Chemical Modeling of Ag/CeO2 Nanoscale Catalysts

Abstract

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.