NO reduction utilizing complex oxide catalysts

Abstract

Precious metal doped BaCeO₃ compounds were synthesized by a solid state method. Physical characterization indicates the low surface area material shares the same perovskite base structure with precious metal species existing as non-metallic, stable cations embedded in the oxide matrix. Catalytic performance of these Pd, Ir, and Rh-doped compounds show that the stabilized precious metal cations have an intrinsic activity ten times higher than typical metallic precious metal sites for the reduction of nitric oxide to dinitrogen under model automotive exhaust gas conditions, likely related to a higher selectivity for the reduction of NO by CO instead of hydrocarbons. Furthermore, the valency of the precious metal dopant can be tuned to extend the activity of the catalyst in excess oxygen conditions.