A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate comprising an inlet end and an outlet end with an axial length L; and a first catalytic region on the substrate; wherein the first catalytic region comprises a first PGM component and a first alumina, wherein the first alumina is doped with a first dopant of at least 5 wt. %, and wherein the first dopant is selected from the group consisting of Zr, Ta, Mo, W, Ti, Nb, and a combination thereof.

Disclosed in the present invention is a tail gas treatment catalyst. The catalyst consists of a carrier, a first catalyst, and a second catalyst. The first catalyst and the second catalyst are provided on both ends of the carrier. The first catalyst can purify pollutants in tail gas. The second catalyst can purify a byproduct, ammonia, obtained by the purification by the first catalyst and pollutants that are not completely purified by the first catalyst. The second catalyst is of a double-layer structure; the lower layer consists of an oxygen storage material, aluminum oxide, and a second active component; the second active component is a composition of Pt and Pd, or a composition of Ce, Fe, Ni and Cu; the upper layer consists of a molecular sieve and a third active component; the third active component is Cu or a composition of Cu and Fe. The tail gas treatment catalyst of the present invention has high purification treatment efficiency, and can significantly reduce the emissions of CH.sub.4, CO, and NO.sub.x in the tail gas, especially reduce the content of the byproduct, NH.sub.3, so that the tail gas can meet China VI emission standards.

A method of making an oxygen storage material (OSM) with developed mesoporosity having a small fraction of pores <10 nm (fresh or aged), and resistance to thermal sintering is provided. This OSM is suitable for use as a catalyst and catalyst support. The method of making this oxygen storage material (OSM) includes the preparation of a solution containing pre-polymerized zirconium oligomers, cerium, rare earth and transition metal salts; the interaction of this solution with a complexing agent that has an affinity towards zirconium; the formation of a zirconium-based precursor; and the co-precipitation of all constituent metal hydroxide with abase.

An exhaust gas control apparatus includes a honeycomb substrate and an inlet cell-side catalyst layer. The honeycomb substrate includes a porous partition wall that defines a plurality of cells extending from an inlet-side end face to an outlet-side end face. The cells include an inlet cell and an outlet cell that are adjacent to each other with the partition wall therebetween. The inlet cell is open at its inlet-side end and is sealed at its outlet-side end. The outlet cell is sealed at its inlet-side end and is open at its outlet-side end. The inlet cell-side catalyst layer is provided on a surface on the inlet cell side of the partition wall and extends from an inlet-side end of the partition wall. Porosity of the inlet cell-side catalyst layer is in a specific range.

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.

A catalytic converter system having oxygen storage materials is disclosed and methods for determining whether to reactivate oxygen storage materials and monitoring failure events of the oxygen storage materials are also disclosed.

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 zeolite; and a second catalytic region beginning at the inlet end, wherein the second catalytic region comprises a second platinum group metal (PGM) component, a second oxygen storage capacity (OSC) material, and a second inorganic oxide; wherein the second PGM component is selected from the group consisting of palladium, platinum, rhodium or a combination thereof.

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, and wherein the coatings Y and Z have the same oxygen storage components and the same carrier materials for noble metals. 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 channels A on the surfaces O.sub.A.

An object of the present invention is to provide a powder of a CeO.sub.2—ZrO.sub.2-based complex oxide which enables to achieve an improvement in the purification performance at a low to middle temperature of an exhaust gas purification catalyst, and, in order to achieve the above-mentioned object, the present invention provides a powder of a CeO.sub.2—ZrO.sub.2-based complex oxide, wherein a pore volume with from-10-to-100-nm diameters after a heat treatment performed at 1,000° C. for 3 hours in an air atmosphere, is 0.35 mL/g or more, and wherein an amount of carbon dioxide desorbed after the heat treatment, as measured by a temperature programmed desorption method, is 80 μmol/g or more.

Provided is an exhaust gas purification device that ensures an improved purification performance and a suppressed pressure loss. An exhaust gas purification device of the present disclosure includes a honeycomb substrate and an inflow cell side catalyst layer. disposed on a surface on the inflow cell side in an inflow side region of the partition wall. When a gas permeability coefficient of an inflow side partition wall portion including the inflow side region of the partition wall and the inflow cell side catalyst layer is Ka and a gas permeability coefficient of an outflow side partition wall portion including an outflow side region at least from the predetermined position to an outflow side end of the partition wall is Kb, a ratio Ka/Kb of the gas permeability coefficients is within a range of 0.4 or more and 0.8 or less.