An exhaust gas purifying catalyst of the present invention includes: a first metal oxide selected from the group of praseodymium oxide, terbium oxide, and a combination thereof; a second metal oxide that is neodymium oxide; a third metal oxide that is zirconia or a combination of zirconia and ceria; and a fourth metal oxide selected from the group of lanthanum oxide, yttrium oxide, barium oxide, calcium oxide, strontium oxide, silicon oxide and a combination thereof.

The present disclosure relates to zero-PGM (ZPGM) catalysts including variations of Nickel-doped Copper-Manganese spinel for improved catalyst performance at the stoichiometric condition for use within three-way catalyst (TWC) applications. The ZPGM catalyst material compositions within the aforementioned ZPGM catalysts are expressed with general formulas of Cu.sub.1-XNi.sub.XMn.sub.2O.sub.4 (A-site substitution) and Cu.sub.1Mn.sub.2-XNi.sub.XO.sub.4 (B-site substitution). The ZPGM catalysts are subjected to a TWC isothermal steady-state sweep test to assess the catalytic performance (e.g., NO conversion). Test results indicate the ZPGM catalysts exhibit higher NO conversions, at stoichiometric condition and lean conditions, when Ni substituted the B-site cation of the CuMn spinel as compared to Ni substituted the A-site cation of the CuMn spinel. Additionally, NO conversions of the ZPGM catalysts are significantly affected, at the stoichiometric condition, by the molar ratio of the Ni dopant within the A or B-site cation of the CuMn spinel.

The disclosure relates to a particulate filter for the treatment of exhaust gas from an internal combustion engine, wherein the particulate filter comprises a catalyst material layer comprising at least one platinum group metal, and the average loading of platinum group metal in the region which is around the whole central axis of the particulate filter and accounts for 20 to 70 vol. % of the total volume of the particulate filter, is 1.1 to 10 times the average loading of platinum group metal in the remaining part of the particulate filter. The particulate filter according to the present invention has a centralized-distributed PGM in the radial direction, shows excellent HC, NOx, and CO conversions and low backpressure.

An exhaust-gas purification catalyst that contains a perovskite-type composite oxide composed of at least Ba, Zr, Y, and Pd.

A method for making a filtration article comprising coating a catalytic material within porous ceramic walls of a honeycomb filter body, thereafter depositing a filler material within the body, and exposing the body to a surface treatment to deposit inorganic deposits within the body on one or more portions of the walls, and burning off the filler material. A filtration article comprises inorganic deposits disposed on walls defining inlet channels; and a catalytic material in pores of walls. At least a portion of the inorganic deposits comprise bridging inorganic deposits which at least partially extend over the pores that extend to the surface of the walls, and such bridging inorganic deposits are spaced away from the catalytic material which is disposed within the walls. Soot treatment is used to space away the bridging inorganic particles from the catalytic material and/or substantially separate the inorganic particles from the catalytic material.

Catalytic articles comprising a first washcoat comprising a first refractory metal oxide support, platinum, palladium, and, optionally, a zeolite, and a second washcoat comprising a second refractory metal oxide support, platinum, and manganese. Also disclosed are exhaust gas treatment systems and methods for treating an exhaust gas stream comprising the same.

Described is a selective catalytic reduction material comprising a spherical particle including an agglomeration of crystals of a molecular sieve. The catalyst is a crystalline material that is effective to catalyze the selective catalytic reduction of nitrogen oxides in the presence of a reductant at temperatures between 200 C. and 600 C. A method for selectively reducing nitrogen oxides and an exhaust gas treatment system are also described.

An oxidation catalyst for treating an exhaust gas from a diesel engine and an exhaust system comprising the oxidation catalyst are described. The oxidation catalyst comprises: a first washcoat region for oxidizing carbon monoxide (CO) and hydrocarbons (HCs), wherein the first washcoat region comprises a first platinum group metal (PGM) and a first support material; a second washcoat region for oxidizing nitric oxide (NO), wherein the second washcoat region comprises platinum (Pt), manganese (Mn) and a second support material; and a substrate having an inlet end and an outlet end; wherein the second washcoat region is arranged to contact the exhaust gas at the outlet end of the substrate and after contact of the exhaust gas with the first washcoat region.

A catalytic filter is provided having a mixture of an SCR catalyst and soot oxidation catalyst where the soot oxidation catalyst is a copper doped ceria, iron doped ceria or manganese doped ceria. The mixture of an SCR catalyst and soot oxidation catalyst provides for a lowering of the peak oxidation temperature for soot removal from the filter. The use of the filter allows for improved soot combustion and reduces the susceptibility of an SCR catalyst contained on a filter to deterioration. The soot oxidation catalyst also improves the resistance of the SCR catalyst to poisoning and subsequent deterioration of SCR performance.

Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.