A DFT+U Study of the Lattice Oxygen Reactivity Toward Direct CO Oxidation on the CeO_2(111) and (110) Surfaces

【摘要】：Density functional theory calculations corrected by on-site Coulomb interaction have been carried out to track down the lattice oxygen reactivity of CeO2(111) and (110) surfaces in direct oxidation of a single CO molecule. The possible elementary steps in CO adsorption and subsequent reactions with lattice oxygen were systematically studied. From the calculated energy, we determined that the lattice oxygen of CeO2(110) surface is more reactive than that of the CeO2(111) surface. By calculating the reaction pathways leading to different final products, we also found that the formation of carbonate species is competitive to CO2 formation and desorption and such effect could be more significant at CeO2(110) compared to CeO2(111). These results may bring us one step ahead to the comprehensive understanding of CO oxidation on CeO2 based materials.