An exhaust gas cleaning catalyst is provided with a fire-resistant three-dimensional structural body, a first catalyst layer provide on a first surface side of the fire-resistant three-dimensional structural body, and a second catalyst layer provided on a side of the first catalyst layer opposite to the fire-resistant three-dimensional structural body. The first catalyst layer contains: a complex oxide including cerium and zirconium; and elemental rhodium. The second catalyst layer contains: a complex oxide including cerium and zirconium; and elemental palladium. The amount of cerium included in the second catalyst layer, in terms of cerium dioxide, is 10-25 g per liter of the fire-resistant three-dimensional structural body.

The present disclosure is directed to compositions comprising Ce-containing mixed oxides, especially those having a stoichiometry of Ln.sub.yCe.sub.xM.sub.wO.sub.z; where 0.15≤x≤0.5, y≤0.25, w=(1−x−y)≥0.5, and z=(2x+2w+1.5y); M is Zr, Hf, Ti, Sn or Ge or a combination thereof; Ln is Y and/or one or more rare earth metals, exclusive of Ce,
and the uses of these compositions. These compositions are characterized by the even distribution of the Ce in the lattice of the mixed oxide.

A catalyst for decomposing an organic substance, the catalyst having a body which has a plurality of pores and the body contains a perovskite-type composite oxide represented by A.sub.xB.sub.yM.sub.zO.sub.w, where the A contains at least one selected from Ba and Sr, the B contains Zr, the M is at least one selected from Mn, Co, Ni, and Fe, 1.001≤x≤1.1, 0.05≤z≤0.2, y+z=1, and w is a positive value that satisfies electrical neutrality. The average pore diameter of the plurality of pores is 49 nm to 260 nm and the pore volume of each of the plurality of pores is 0.08 cm.sup.3/g to 0.37 cm.sup.3/g.

This invention relates to an aqueous dispersion of particles, the dispersion having a particle content of 10-70 wt %, and the particles comprising, on an oxide basis: (a) 10-98 wt % in total of ZrO.sub.2+HfO.sub.2, and (b) 2-90 wt % in total of AI.sub.2O.sub.3, CeO.sub.2, La.sub.2O.sub.3, Nd.sub.2O.sub.3, Pr.sub.6O.sub.11, Y.sub.2O.sub.3, or a transition metal oxide, wherein the dispersion has a Z-average particle size of 100-350 nm and the particles have a crystallite size of 1-9 nm. The invention also relates to a substrate coated with the aqueous dispersion of particles.

The invention relates to a catalytic converter for removing carbon monoxide, hydrocarbons and nitrogen oxides from the exhaust gas of internal combustion engines operated with stoichiometric air-fuel mixture, which catalytic converter comprises a substrate of the length L and a catalytic coating, characterized in that the coating is located on the walls of the substrate and extends, proceeding from one end of the substrate, over a length corresponding to at least 50% of L and comprises active aluminum oxide, two cerium/zirconium/rare-earth-metal mixed oxides different from each other, and at least one platinum group metal.

Described herein are catalytic converter substrates or cores based on triply periodic minimal surfaces (TPMS) geometries, along with methods of making and using the same.

JMZ-1, a zeolite having a CHA structure and containing trimethyl(cyclohexylmethyl)ammonium cations as a structure directing agent is described. A calcined zeolite, JMZ-1C, that does not contain a structure directing agent, is also described. Metal containing JMZ-1C has improved SCR activity compared to CHA-containing zeolites having the same metal loading and comparable silica:alumina ratios (SAR). Methods of preparing JMZ-1, JMZ-1C and metal containing calcined counterparts of JMZ-1C are described along with methods of using JMZ-1C and metal containing calcined counterparts of JMZ-1C in treating exhaust gases.

The purpose of the present invention is to provide a zirconia-based porous body which can be pulverized in a relatively short time and in which performance deterioration caused by pulverization is suppressed. The present invention pertains to a zirconia-based porous body in which the total pore volume is at least 1.0 ml/g, the pore volume of pores having a diameter of 20-100 nm (exclusive of 100) is at most 0.3 ml/g, and the pore volume of pores having a diameter of 100-1000 nm is at least 0.5 ml/g.

A catalyst for gasoline engine exhaust gas after-treatment, comprising Pt and optionally at least one other platinum group metal on a hydrothermal stable support material which is coated onto a gasoline particulate filter. The catalyst oxidizes particulate matter trapped in the gasoline particulate filter under low temperature and abates NO.sub.x, CO and HC. Also a process for preparing the catalyst is disclosed, and a method for after-treatment of gasoline engine exhaust gas using the catalyst is disclosed.

A nanocrystal-sized cerium-zirconium-aluminum mixed oxide material includes at least 20% by mass zirconium oxide; between 5% to 55% by mass cerium oxide; between 5% to 60% by mass aluminum oxide; and a total of 25% or less by mass of at least one oxide of a rare earth metal selected from the group of lanthanum, neodymium, praseodymium, or yttrium. The nanocrystal-sized cerium-zirconium-aluminum mixed oxide exhibits hierarchically ordered aggregates having a dso particle size less than 1.5 μm, and retains at least 80% of surface area and pore volume after ageing at temperature higher than 1000° C. for at least 6 hours. The nanocrystal-sized cerium-zirconium-aluminum mixed oxide material is prepared using a co-precipitation method followed by milling the dried and calcined oxide material. The nanocrystal-sized cerium-zirconium-aluminum mixed oxide material forms a particulate filter that may be used in an exhaust system arising from a gas or diesel engine