Multi-functional catalysts for the oxidation of no, the oxidation of nh3 and the selective catalytic reduction of nox

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

• (i) a 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 the interface between the passages and the internal walls is defined by the surface of the internal walls;
• (ii) a first coating comprising one or more of a vanadium oxide and a zeolitic material comprising one or more of copper and iron;
• (iii) a second coating comprising a platinum group metal component supported on a non-zeolitic oxidic material, wherein the platinum group metal component supported on the non-zeolitic oxidic material is present in the second coating at a first loading L1, wherein the first loading is a sum of the loading of the platinum group metal component and the loading of the non-zeolitic oxidic material;
• the second coating further comprising a zeolitic material comprising one or more of copper and iron, wherein the zeolitic material comprising one or more of copper and iron is present in the second coating at a second loading L2, wherein the second loading is a sum of the loading of the zeolitic material and the loading of the one or more of copper and iron;
• wherein the second coating is disposed on the surface of the internal walls over y % of the axial length of the substrate from the outlet end to the inlet end, with y ranging from 10 to 90;
• wherein the first coating extends over x % of the axial length of the substrate from the inlet end to the outlet end and is disposed on the second coating and on the surface of the internal walls, with x ranging from 95 to 100;
• wherein the ratio of the first loading, in g/l, to the second loading, in g/l, L1:L2, is of at least 1.1:1.

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 substrate, wherein 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, and wherein the interface between the passages and the internal walls is defined by the surface of the internal walls;
• (b) providing a slurry comprising a solvent, a platinum group metal component, a non-zeolitic oxidic material, and a zeolitic material comprising one or more of copper and iron, disposing the slurry on the surface of the internal walls over y % of the substrate axial length from the outlet end to the inlet end, with y ranging from 10 to 90, calcining the slurry disposed on the substrate, obtaining a second coating disposed on the surface of the internal walls of the substrate;
• and
• (c) providing a slurry comprising a solvent and one or more of a vanadium oxide and a zeolitic material comprising one or more of copper and iron, disposing the slurry over x % of the substrate axial length on the second coating from the inlet end to the outlet end, with x ranging from 95 to 100, calcining the slurry disposed on the substrate, obtaining a first coating disposed on the surface of the internal walls of the substrate and on the second coating.