Surface stabilities and NO oxidation kinetics on hexagonal-phase LaCoO3 facets: a first-principles study†
LaCoO3 perovskite has recently received great attention as a potential alternative to precious metal based NO oxidation catalysts. We report here a comprehensive first-principles study of the NO oxidation kinetics on differently re-constructed hexagonal-phase LaCoO3 facets. Among the 42 low-index facets considered, the (102) LaO-, (104) O2- and (0001) LaO3-terminated facets were found to be thermodynamically stable and likely to be exposed in LaCoO3 oxide nanoparticles. Among these stable facets, the (0001) LaO3-terminated surface is catalytically most active towards NO oxidation, with the reaction proceeding through the mono-vacancy Mars–van Krevelen mechanism. Our study shed light on the atomistic scale NO oxidation mechanism on LaCoO3 facets and can aid further optimization of the catalyst.