Methods 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.

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 oxygen storage capacity (OSC) of the TWC2 is greater than the OSC of the GPF, wherein the OSC is determined in mg/l of the volume of the device.

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

An exhaust gas purification system for a gasoline engine is described the system 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 oxygen storage capacity (OSC) of the GPF is greater than the OSC of the TWC1, wherein the OSC is determined in mg/l of the volume of the device.

The present invention relates to a three-way catalyst (TWC) for treatment of exhaust gases from internal combustion engines operated with a predominantly stoichiometric air/fuel ratio, so called spark ignited engines.

The presently claimed invention provides a layered catalytic article and an exhaust system. The catalytic article comprises a first layer comprising platinum, a first platinum group metal component other than platinum, a ceria-alumina composite, and an oxygen storage component; wherein platinum is supported on the ceria-alumina component; the platinum group metal component is selected from palladium, rhodium or a combination thereof and the platinum group metal component is supported on the oxygen storage component; a second layer comprising a second platinum group metal component; and a refractory alumina component, an oxygen storage component or a combination thereof; wherein the second platinum group component is selected from platinum, palladium, rhodium or a combination thereof; and a substrate, wherein the amount of platinum is 10 to 80 wt. %, based on the total weight of platinum, palladium and rhodium. The presently claimed invention also provides a process for the preparation of a layered catalytic article and use of the catalytic article and the exhaust system for purifying a gaseous exhaust stream comprising hydrocarbons, carbon monoxide, and nitrogen oxides.

The present invention provides a tri-metallic layered catalytic article comprising a first layer comprising palladium supported on at least one of an oxygen storage component, and an alumina component; a second layer comprising platinum and rhodium, each supported on at least one of an oxygen storage component and a zirconia component; and a substrate, wherein the weight ratio of palladium to platinum is in the range of 1.0:0.4 to 1:2. The present invention also provides a process for preparing the tri-metallic layered catalytic article, an exhaust system for internal combustion engine and use of the tri-metallic layered catalytic article for purifying a gaseous exhaust stream.

The present disclosure is directed to compositions for use in oxygen capture applications, for example in three-way catalysts (TWC) systems. In some embodiments, the compositions comprise composites of aggregated and/or fused primary particles, the aggregated and/or fused primary particles collectively having the formulae [MnO.sub.x]:.sub.y:[La.sub.zMnO.sub.3].sub.1-y; wherein x is in a range from about 1 to 2.5; y is in a range from about 1 to about 30 wt %, or from about 1 to about 20 wt % or from about 2-10 wt % or from about 2 to about 5 wt %; and z is about 0.7 to about 1.1; and the La.sub.zMnO.sub.3 is a crystalline perovskite phase; the aggregated and/or fused primary particles of the composite having a mean surface area in a range of from about 25 to about 60 m.sup.2/g, preferably from about 27 to about 45 m.sup.2/g. In preferred embodiments, these compositions further comprise low levels of at least one platinum group metal (PGM), preferably Pd.

A three-way catalyst article, and its use in an exhaust system for compressed natural gas engines, is disclosed. The catalyst article for treating exhaust gas from compressed natural gas (CNG) engine comprising: a substrate comprising an inlet end, an outlet end with an axial length L; a first catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the first catalytic region comprises a first PGM component; and a second catalytic region beginning at the inlet end, wherein the second catalytic region comprises a second PGM component; wherein the first PGM component comprises palladium, platinum, or a combination thereof; and wherein the second PGM component comprises rhodium.

A particulate filter includes a base material having a wall-flow structure including porous partition walls partitioning inlet and outlet cells, and wash-coating layers held inside partition walls. The wash-coating layers include inlet layers each formed from vicinity of an end portion at exhaust gas inflow side to have predetermined length and thickness and outlet layers each formed from vicinity of end portion at exhaust gas outflow side to have a predetermined length and thickness. The inlet and the outlet layers partially overlap with each other. Inlet layers of particulate filter contain substantially no noble metal catalyst, and outlet layers contain noble metal catalyst. Accordingly, PM collection performance can be easily enhanced in inlet region, and high gas distributability (pressure loss suppression performance) can be maintained in outlet region. Accordingly, it is possible to provide particulate filter capable of achieving high levels of PM collection performance and pressure loss suppression performance.

The present invention discloses a rare-earth-manganese/cerium-zirconium-based composite compound, a method for preparing the same, and a use thereof. The composite compound is of a core-shell structure with a general formula expressed as: A RE.sub.cB.sub.aO.sub.b-(1-A)Ce.sub.xZr.sub.(1-x-y)M.sub.yO.sub.2-z, wherein 0.1≤A≤0.3, preferably 0.1≤A≤0.2; a shell layer has a main component of rare-earth manganese oxide with a general formula of RE.sub.cMn.sub.aO.sub.b, wherein RE is a rare-earth element or a combination of more than one rare-earth elements, and B is Mn or a combination of Mn and a transition metal element, 1≤a≤8, 2≤b≤18, and 0.25≤c≤4; and a core has a main component of cerium-zirconium composite oxide with a general formula of Ce.sub.xZr.sub.(1-x-y)M.sub.yO.sub.2-z, wherein M is one or more non-cerium rare-earth elements, 0.1≤x≤0.9, 0≤y≤0.3, and 0.01≤z≤0.3. The composite compound enhances an oxygen storage capacity of a cerium-zirconium material through an interface effect, thereby increasing a conversion rate of a nitrogen oxide.