Catalyst compositions, articles, systems and methods related to a three-way-catalyst composition comprising alumina doped with a transition metal.

An object of the present disclosure is to provide an exhaust gas purification catalyst demonstrating superior storage of NOx contained in exhaust gas.

The exhaust gas purification catalyst of the present disclosure has a substrate, a first catalyst layer containing a catalytic metal for NOx reduction and a NOx storage material and formed on the substrate, and a second catalyst layer containing a catalytic metal for NOx oxidation and formed on the first catalyst layer. In the exhaust gas purification catalyst of the present disclosure, the value obtained by dividing the volume of all large pores having a pore volume of 1000 μm.sup.3 or more by the total volume of all medium pores of having a pore volume of 10 μm.sup.3 to 1000 μm.sup.3 in the second catalyst layer is 2.44 or less.

A catalyst for abating a nitrogen oxide includes: a honeycomb substrate including a plurality of cell passages partitioned by a cell barrier rib; and a coating layer positioned on the internal side of the cell passages. The coating layer includes a support including Mg-substituted alumina (MgAl.sub.2O.sub.4), ceria (Ce), and a composite ceria; and Ba and a noble metal catalyst selected from the group consisting of Pt, Pd, Rh and combinations thereof, which are supported on the support. Also provided is a catalyst system for abating a nitrogen oxide includes the coating layer.

When sizes of particles supporting a catalyst metal remain relatively large but sizes of particles not supporting a catalyst metal are minimized among metal oxide particles included in a catalyst coating layer, it is possible to decrease a thickness of the catalyst coating layer while maintaining durability and improve gas diffusibility of the coating layer. Therefore, a thickness of the catalyst coating is decreased without decreasing durability and a catalyst can exhibit high exhaust gas purification performance even under high load conditions.

A catalyst converter includes: a substrate (1) having a cell structure formed of a center area (1A) having the highest cell density, a peripheral area (1C) having the lowest cell density, and an intermediate area (1B) having the cell density between that of the center area and that of the peripheral area; a first catalyst layer formed in the center area (1A); a second catalyst layer formed in the intermediate area (1B); and a third catalyst layer formed in the peripheral area (1C). A length in a longitudinal direction of the second catalyst layer is longer than that of the first catalyst layer. A length in the longitudinal direction of the third catalyst layer is longer than that of the second catalyst layer. A ratio of the length in the longitudinal direction of the first catalyst layer to the length of the substrate is 65% or more.

Provide is a catalytic converter including a substrate which includes regions having different cell densities, in which exhaust gas purification performance is superior in all the regions of the substrate. A catalytic converter 10 includes catalyst layers in which a noble metal catalyst is supported on a support in surfaces of cell walls 2 of a substrate 1 having a cell structure in a longitudinal direction of the substrate 1 in which gas flows, in which the substrate 1 has a first region 1A having a relatively high cell density and a second region 1B having a relatively low cell density, and a ratio of a thickness of a catalyst layer 3A in the second region 1B to a thickness of a catalyst layer 3 in the first region 1A is in a range of more than 0.95 times and 1.2 times or less.

Composites of mixed metal oxides for an exhaust gas purifying catalyst comprise the following co-precipitated materials by weight of the composite: zirconia in an amount in the range of 55-99%; titania in an amount in the range of 1-25%; a promoter and/or a stabilizer in an amount in the range of 0-20%. These composites are effective as supports for platinum group metals (PGMs), in particular rhodium.

[Summary]

[Problem]

The problem addressed by the present invention lies in providing an exhaust gas purification filter which can efficiently treat particulate matter in exhaust gas.

[Solution]

The present invention provides an exhaust gas purification filter including a substrate comprising a plurality of porous partitions, wherein the partitions form an exhaust gas flow path, a porous catalytic layer is provided on the partitions and the catalytic layer having a thickness of 10 μm or greater is provided over at least 20% of the total length of the partitions in the lengthwise direction thereof, and the catalytic layer having a thickness of 10 μm or greater is not present on the partitions 15 mm from an outflow side.

A core-shell oxide material comprises: a core which comprises a ceria-zirconia based solid solution powder having at least one ordered phase of a pyrochlore phase and a κ phase; and a shell which comprises an alumina based oxide disposed on at least a portion of a surface of the core.

An emissions control substrate. The emissions control substrate includes a first end and a second end opposite to the first end. A plurality of channels extend between the first end and the second end, and are configured to direct exhaust from an engine through the substrate. The emissions control substrate is three-dimensionally printed