Nitrogen oxide storage catalyst with reduced desulphurisation temperature

摘要

In the production of a nitrogen oxide storage (NOS) catalyst (I) with reduced desulfurization temperature, based on catalyst (II) comprising (i) platinum (Pt) on an oxide carrier (A) and (ii) NOS component(s) on oxide carrier(s) (C), the basicity of the Pt environment is reduced by applying at least a third of the Pt to an oxide carrier (A) having a lower basicity than (A). Production of a nitrogen oxide storage (NOS) catalyst (I) with reduced desulfurization temperature, based on a conventional NOS catalyst (II) comprising (i) platinum (Pt) on a high-surface, high-melting oxide carrier (A) and (ii) NOS component(s) on- high-surface, high-melting oxide carrier(s) (C), involves reducing the basicity of the chemical environment of the Pt by applying at least a third of the Pt to a high-surface, high-melting oxide carrier (A) having a lower basicity than (A). An independent claim is included for an NOS catalyst (I'), consisting of components (i) and (ii), where (a) half of the Pt is on the less basic carrier (B) and the other half is on the more basic carrier (A) and (b) (I') additionally contains at least 5 wt. % (based on the overall catalytically active components) of cerium (Ce) oxide, Ce-zirconium mixed oxide and/or rare earth metal-doped Ce oxide.