Abstract:
The present invention relates to a process for the preparation of a catalyst, said process comprising: (i) providing a substrate which is optionally coated with one or more coating layers; (ii) impregnating one or more particulate support materials with one or more platinum group elements; (iii) adding one or more alkaline earth elements and one or more solvents to the product obtained in step (ii) to obtain a slurry; (iv) adjusting the pH of the slurry obtained in step (iii) to a value comprised in the range of from 7 to 10, in case the pH should not fall within this range; (v) adjusting the pH of the slurry to a value comprised in the range of from 2 to 6; (vi) optionally milling the slurry obtained in step (v); (vii) providing the slurry obtained in step (vi) onto the optionally coated substrate in one or more coating steps, as well as to a catalyst which is obtainable according to said process and its use in the treatment of exhaust gas.
Abstract:
Ceria-Zirconia-Mixed oxide particles and process for their production by pyrolysis, wherein the process comprising: (1) providing a mixture comprising a solvent, one or more precursor compounds of ceria, one or more precursor compounds of zirconia, and one or more precursor compounds of one or more rare earth oxides other than ceria and/or one or more precursor compounds of yttria; (2) forming an aerosol of the mixture provided in step (1); and (3) pyrolyzing the aerosol of step (2) to obtain mixed oxide particles; wherein the content of the rare earth oxides other than ceria and/or of yttria in the mixed oxide particles formed in step (3) is comprised in the range of from 0.1 to 4.9 wt.-% based on the total weight of the rare earth oxides, yttria, and zirconia contained in the mixed oxide particles, as well as to mixed oxide particles obtainable from flame spray pyrolysis and to their use as an oxygen storage component, a catalyst and/or as a catalyst support.
Abstract:
Described is a catalyzed soot filter wherein the inlet coating of the filter comprises an oxidation catalyst comprising platinum (Pt) and optionally palladium (Pd), wherein the outlet coating of the filter comprises an oxidation catalyst comprising Pd and optionally Pt, wherein the Pt concentration in the outlet coating is lower than the Pt concentration in the inlet coating and wherein the weight ratio of Pt:Pd in the outlet coating is in the range of from 0:1 to 2:1; and wherein the inlet coating and the outlet coating are present on the wall flow substrate at a coating loading ratio in the range of from 0.5 to 1.5, calculated as ratio of the loading of the inlet coating (in g/inch3 (g/(2.54 cm)3)):loading of the outlet coating (in g/inch3 (g/(2.54 cm)3)). Systems include such catalyzed soot filters, methods of diesel engine exhaust gas treatment and methods of manufacturing catalyzed soot filters are also described.
Abstract:
The present invention relates to a catalyzed soot filter which comprises a wall flow substrate with an inlet end, an outlet end, a substrate axial length extending between the inlet end and the outlet end, and a plurality of passages defined by internal walls of the wall flow substrate wherein the plurality of passages comprise inlet passages having an open inlet end and a closed outlet end, and outlet passages having a closed inlet end and an open outlet end, and wherein the internal walls of the inlet passages comprise a zoned first inlet coating, the internal walls of the outlet passages comprise a zoned first outlet coating, and wherein the first inlet coating and the first outlet coating are present on the wall flow substrate at a coating loading ratio of less than 0.5.
Abstract:
A layered diesel oxidation catalyst (DOC) comprises: a) a carrier substrate; b) a diesel oxidation catalytic material comprising bl)a first layer located on the carrier substrate, the first layer comprising palladium impregnated on a support material comprising ceria in an amount of at least 45 weight% based on the total weight of the support material, and optionally comprising platinum; b2) a second layer located on the first layer, the second layer comprising palladium and platinum each impregnated on a support material comprising a metal oxide; wherein the platinum to palladium weight ratio of the first layer is lower than the platinum to palladium weight ratio of the second layer.
Abstract:
A catalyzed soot filter is provided wherein its inlet coating comprises an oxidation catalyst comprising platinum (Pt) and optionally palladium (Pd), and its outlet coating comprises an oxidation catalyst comprising Pd and optionally Pt. The Pt concentration in the outlet coating is lower than that in the inlet coating. The weight ratio of Pt:Pd in the outlet coating is in the range of 0:1-2:1. The inlet coating and the outlet coating are present on the wall flow substrate at a coating loading ratio in the range of 0.5-1.5, calculated as ratio of the loading of the inlet coating (in g/inch3(g/(2.54cm)3)):loading of the outlet coating (in g/inch3(g/(2.54cm)3)).
Abstract:
The present invention relates to a catalyzed soot filter which comprises a wall flow substrate with an inlet end, an outlet end, a substrate axial length extending between the inlet end and the outlet end, and a plurality of passages defined by internal walls of the wall flow substrate wherein the plurality of passages comprise inlet passages having an open inlet end and a closed outlet end, and outlet passages having a closed inlet end and an open outlet end, and wherein the internal walls of the inlet passages comprise a zoned first inlet coating, the internal walls of the outlet passages comprise a zoned first outlet coating, and wherein the first inlet coating and the first outlet coating are present on the wall flow substrate at a coating loading ratio of less than 0.5.
Abstract:
The present invention relates to a diesel oxidation catalyst comprising a carrier substrate, and a first washcoat layer disposed on the substrate, the first washcoat layer comprising palladium supported on a support material comprising a metal oxide, gold supported on a support material comprising a metal oxide, and a ceria comprising compound, as well as a process for the preparation of such catalyst.