This disclosure is directed to catalyst compositions, catalytic articles for purifying exhaust gas emissions and methods of making and using the same. In particular, the disclosure relates to a catalytic article including a catalytic material on a substrate, wherein the catalytic material has a first layer and a second layer. The first layer includes a platinum group metal (PGM) component impregnated on a porous support material; and the second layer includes a rhodium component impregnated on a support material, wherein the support material is a composite material including zirconia doped with baria, alumina, or combinations thereof, wherein the zirconia-based support material includes zirconia in an amount from about 80 to about 99 wt. %.

Subject of the invention is an exhaust gas purification system for a gasoline engine, comprising in consecutive order the following devices:

a first three-way-catalyst (TWC1), a gasoline particulate filter (GPF) and a second three-way-catalyst (TWC2),

wherein the platinum-group metal concentration (PGM) of the GPF is at least 40% greater than the PGM of the TWC2, wherein the PGM is determined in g/ft3 of the volume of the device,

The invention also relates to methods in which the system is used and uses of the system.

Methods and systems are provided for emissions control of a vehicle. In one example, a catalyst may include a cerium-based support material and a transition metal catalyst loaded on the support material, the transition metal catalyst including nickel and copper, wherein nickel in the transition metal catalyst is included in a monatomic layer loaded on the support material. In some examples, limiting nickel to the monatomic layer may mitigate extensive transition metal catalyst degradation ascribed to sintering of thicker nickel washcoat layers. Further, by utilizing the cerium-based support material, side reactions involving nickel in the transition metal catalyst with other support materials may be prevented.

The disclosure relates to a three-way conversion catalyst for the treatment of an exhaust gas comprising nitrogen monoxide, carbon monoxide, and hydrocarbon, wherein the catalyst comprises: (i) a substrate; (ii) a first coating comprising rhodium supported on a first oxidic component; (iii) a second coating comprising palladium supported on a non-zeolitic oxidic material, wherein the non-zeolitic oxidic material comprises manganese and a second oxidic component, wherein the second coating consists of 0 weight-% to 0.001 weight-% of platinum; wherein the first coating is disposed on the substrate over x % of the axial length, with x ranging from 80 to 100; wherein the second coating extends over y % of the axial length from the inlet end to the outlet end and is disposed on the first coating, with y ranging from 20 to x.

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 CeO.sub.2 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 ZrO.sub.2 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.

The present disclosure relates to a cerium-zirconium-based composite oxide having gradient element distribution and a preparation method therefor. According to the present disclosure, the cerium-zirconium-based composite oxide having gradient element distribution is prepared by a step-by-step precipitation method. First, a zirconium-rich component is precipitated to form a crystal structure and a crystal grain stack structure which have high thermal stability, slow down the segregation of zirconium on a surface after high-temperature treatment, and reduce element migration among crystal grains; second, a cerium-rich component is precipitated to improve the cerium content of the surface layers of the crystal grains, improve the utilization rate of the cerium element, and improve the oxygen storage amount and the oxygen storage rate.

An internal combustion engine control device and a catalyst deterioration diagnostic method according to the present invention control the amount of fuel to be supplied to an internal combustion engine such that the air-fuel ratio of the exhaust on the downstream side of the exhaust purification catalyst is alternately switched between rich and lean, measure the oxygen storage capability of the exhaust purification catalyst during a measurement period within a reversal period of the air-fuel ratio, and diagnose deterioration of the exhaust purification catalyst based on a measurement value of the oxygen storage capability. A time point at which the output of an exhaust sensor indicates that the air-fuel ratio of the exhaust on the downstream side of the exhaust purification catalyst begins to change from a vicinity of a stoichiometric air-fuel ratio to rich or lean is set as the time of end of the measurement period.

Described herein is a layered catalytic article which includes a) a top layer including a front zone and a rear zone, where the front zone includes a palladium component and a rhodium component, supported individually or together on a support, and the rear zone includes a platinum component, a rhodium component and optionally a palladium component, supported individually or together on a support; b) a bottom layer including a platinum component and a palladium component supported individually or together on a support; and c) a substrate. Also described herein are an exhaust treatment system including the layered catalytic article and a method of using the layered catalytic article for abatement of hydrocarbons, carbon monoxide and nitrogen oxides in an exhaust stream.

Disclosed herein is a catalytic article including a first layer having at least one first platinum group metal supported on a first support, where the first support includes an alumina and a first oxygen storage component, and the first oxygen storage component includes ceria-zirconia; a second layer including at least one second platinum group metal supported on a second support, where the second support includes an alumina and a second oxygen storage component, and the second oxygen storage component includes ceria-zirconia; and a substrate . Further disclosed herein is a process for preparing the catalytic article.

The present invention relates to a particulate filter which comprises a wall-flow filter of length L and two different catalytically active coatings Y and Z, wherein the wall flow filter comprises channels E and A that extend in parallel between a first and a second end of the wall-flow filter and are separated by porous walls which form the surfaces O.sub.E and O.sub.A, respectively, and wherein the channels E are closed at the second end and the channels A are closed at the first end. The invention is characterized in that the coating Y is located in the channels E on the surfaces O.sub.E and the coating Z is located in the porous walls.