| CPC F01N 3/2066 (2013.01) [B01J 21/063 (2013.01); B01J 21/08 (2013.01); B01J 23/6482 (2013.01); B01J 29/723 (2013.01); B01J 35/19 (2024.01); B01J 37/0215 (2013.01); F01N 2570/14 (2013.01); F01N 2570/18 (2013.01); F01N 2590/08 (2013.01)] | 15 Claims |
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1. A catalyst for the oxidation of NO, for the oxidation of ammonia, and for the selective catalytic reduction of NOx, comprising:
(i) a flow-through 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 flow-through substrate extending therethrough, wherein an interface between the plurality of passages and the internal walls is defined by a 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 and further comprising one or more of a vanadium oxide and a zeolitic material comprising one or more of copper and iron; and
(iv) a third coating comprising a platinum group metal component supported on an oxidic material;
wherein the third coating is disposed on the surface of the internal walls over z % of the axial length of the substrate from the outlet end to the inlet end, wherein z ranges from 20 to 80;
wherein the second coating extends over y % of the axial length of the substrate from the inlet end to the outlet end and is disposed on the surface of the internal walls, wherein y ranges from 20 to 80;
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 third coating, wherein x ranges from 95 to 100.
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