Multi-functional catalysts for the oxidation of NO, the oxidation of NH3 and the selective catalytic reduction of NOx

A method for preparing a catalyst for the oxidation of NO, for the oxidation of ammonia, and for the selective catalytic reduction of NOx comprising:

• (a) providing an uncoated flow-through substrate, the substrate comprising an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by internal walls of the substrate extending therethrough, wherein an interface between the plurality of passages and the internal walls is defined by [the] a surface of the internal walls;
• (b) providing a slurry comprising a platinum group metal component, an oxidic material, and a solvent, disposing the slurry on the surface of the internal walls of the substrate, over z % of the substrate axial length from the outlet end to the inlet end, wherein z ranges from 20 to 80, calcining the slurry disposed on the substrate, obtaining a third coating disposed on the substrate;
• (c) providing a slurry comprising a platinum group metal component, a non-zeolitic oxidic material and one or more of a vanadium oxide and a zeolitic material comprising one or more of copper and iron, and a solvent, disposing the slurry on the surface of the internal walls over y % of the substrate axial length from the inlet end to the outlet end, wherein y ranges from 20 to 80, calcining the slurry disposed on the substrate, obtaining a second coating disposed on the substrate;
• and
• (d) providing a slurry comprising one or more of a vanadium oxide and a zeolitic material comprising one or more of copper and iron, and a solvent, disposing the slurry over x % of the substrate axial length on the second coating from the inlet end to the outlet end, wherein x ranges from 95 to 100, calcining the slurry disposed on the substrate, obtaining the catalyst for the oxidation of NO, for the oxidation of ammonia and for the selective catalytic reduction of NOx.