Influence of Ce doping on catalytic oxidation of NO on LaCoO_3 (011) surface: A DFT study

摘要

The catalytic oxidation of NO on the undoped and Ce-doped LaCoO3 (011) surfaces has been systematically studied by utilizing the density functional theory (DFT) method. The extra-lattice oxygen and Mars-van Krevelen (MvK) mechanisms of NO oxidation are considered. According to our calculations, the extra-lattice oxygen mechanism is more likely to occur on the undoped and Ce-doped LaO-terminated LaCoO3 (011) surfaces, while the MvK mechanism is more suitable for the undoped and Ce-doped CoO2 -terminated LaCoO3 (011) surfaces. By comparing and analyzing the same NO oxidation pathway on the undoped and Ce-doped surfaces, it is proved that the Ce doping is favorable for the LaO-terminated LaCoO3 (011) surface, but harmful for the CoO2-terminated LaCoO3 (011) surface. In our research on NO oxidation, the addition of Ce dopant contributes to the LaO-terminated LaCoO3 (011) surface by reducing the energy barriers of O-2 dissociation and NO2 desorption.