CATALYST FOR THE OXIDATION OF NO, THE OXIDATION OF A HYDROCARBON, THE OXIDATION OF NH3 AND THE SELECTIVE CATALYTIC REDUCTION OF NOX

摘要

The present invention relates to a catalyst for the oxidation of NO, for the oxidation of ammonia, for the oxidation of HC and for the selective catalytic reduction of NOx, comprising 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; a first coating comprising one or more of a vanadium oxide and a zeolitic material comprising one or more of copper and iron; a second coating comprising a first platinum group metal component supported on a non-zeolitic first oxidic material and further comprising one or more of a vanadium oxide and a zeolitic material comprising one or more of copper and iron; optionally a third coating comprising a second platinum group metal component supported on a second oxidic material; wherein the third coating is disposed on the surface of the internal walls and under the second coating over z % of the axial length of the substrate from the outlet end to the inlet end, with z being in the range of from 0 to 100; 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 either on the surface of the internal walls, or on the surface of the internal walls and the third coating, or on the third coating, with y being in the range of from 95 to 100; 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, with x being in the range of from 20 to y.