Abstract:
The present invention provides a catalyst composition comprising a) platinum; b) rhodium; and c) a ceria-alumina composite, a zirconia composite or a mixture thereof, wherein platinum is supported on the ceria-alumina composite, zirconia composite or mixture thereof, wherein rhodium is supported on the ceria-alumina composite, zirconia composite or mixture thereof, wherein CeO2 in the ceria alumina composite is 1.0 to 50 wt. %, based on the total weight of the ceria-alumina composite, wherein the amount of ZrO2 in the zirconia composite is 50 to 99 wt. %, based on the total weight of the zirconia composite. The present invention also provides a catalytic article comprising the catalyst composition and its preparation.
Abstract:
The present invention relates to a composite oxide comprising ceria, praseodymia and alumina, wherein the cerium : praseodymium molar ratio of the composite oxide is 84:16 or less, as well as to a method of preparing the composite oxide and to its use, in particular in a method of treating an exhaust gas stream.
Abstract:
The present invention provides a catalyst composition comprising at least one platinum group metal; and at least one complex metal oxide wherein the at least one platinum group metal is supported on the at least complex metal oxide, wherein the complex metal oxide comprises ceria (calculated as CeO2) in an amount of about 50 to about 99 wt.%, based on the total weight of the complex metal oxide; and zirconia (calculated as ZrO2) in an amount of about 1.0 to about 50 wt.%, based on the total weight the complex metal oxide. The present invention also provides a catalytic article made from said catalyst composition, its preparation and use for the treatment of the exhaust gases.
Abstract:
The present invention provides a catalytic article comprising a substrate; a bottom washcoat deposited on the substrate; and a top washcoat deposited on the bottom coat, wherein the bottom washcoat comprises a zoned configuration, wherein the zoned configuration comprises a first zone and a second zone, wherein the first zone comprises palladium supported on ceria-zirconia mixed oxide or alumina or both, wherein the second zone comprises platinum supported on a ceria-alumina composite, wherein the top washcoat comprises rhodium supported on an alumina or a ceria-alumina composite. The present invention also provides a process for the preparation of the catalytic article, and it use for purifying a gaseous exhaust stream.
Abstract:
The present invention relates to a composite oxide comprising ceria, praseodymia and alumina, wherein the cerium : praseodymium molar ratio of the composite oxide is 84:16 or less, as well as to a method of preparing the composite oxide and to its use, in particular in a method of treating an exhaust gas stream.
Abstract:
A diesel oxidation catalyst for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO) and the reduction of nitrogen oxides (NOx) is described. More particularly, the present invention is directed to a washcoat composition comprising high silica to alumina zeolite and platinum and palladium such that the zeolite minimizes negative interactions of these platinum group metals with the zeolite.