Surface reactivity of prereduced rare earth oxides with nitric oxide: New approach for NO decomposition

Abstract

Direct decomposition of NO to N2 by rare earth oxides prereduced with H2 was studied. CeO2 and Pr6O11 prereduced at 773 K, in which many oxygen anion vacancies exist, decomposed NO to N2 at 673 K. The addition of Pt accelerated the dissociation of NO to N2. The amount of NO decomposed to N2 and N2O by Pt supported on rare earth oxides was strongly related to the oxygen mobility and to the amount of oxygen anion vacancies in the surface/subsurface. Particularly, for Pt/CeO2, oxygen diffusion on the surface but not in the bulk was the most important factor determining the NO decomposition activity.