Phosphate-Containing CeO2-ZrO2 Solid for NH3-SCR Catalysis: Effects of Oxygen Vacancies on NOx Adsorption and Activity

We found that NO adsorbed on ceria catalyst are firstly oxidized to nitrites by surface oxygen, and then oxidized to nitrates by subsurface/lattice oxygen. NH₄NO₃ rather than NH₄NO₂ species are more important intermediates in NH₃-SCR reaction on ceria catalyst. Oxygen vacancies lead to more strongly ad-nitrite species on ceria catalyst.