A method for the preparation of a catalyzed monolithic body or a catalyzed particular filter. The method includes the step of suctioning a sol-solution containing catalytically active material and metal oxide catalyst carriers or precursors thereof into pores of a monolithic substrate, solely by capillary forces and without the application of vacuum or pressure.

Provided is a catalyst article for simultaneously remediating the nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons present in diesel engine exhaust streams. The catalyst article has a soot filter coated with a material effective in the Selective Catalytic Reduction (SCR) of NOx by a reductant, e.g., ammonia.

A catalytic wall-flow filter with improved ammonia emission control, and its use in an exhaust system for gasoline engines, are disclosed. The catalytic wall-flow filter comprises a wall-flow filter substrate; a first catalyst coated on the first plurality of channels, wherein the first catalyst comprises a zeolite; and a second catalyst coated on the second plurality of channels. The second catalyst comprises a platinum group metal (PGM) component, an oxygen storage capacity (OSC) material, and an inorganic oxide support.

Provided are automotive catalyst composites having a catalytic material on a carrier, wherein the catalytic material comprises at least two layers. The first layer is deposited directly on the carrier and comprises a first palladium component supported on a first refractory metal oxide component, a first oxygen storage component, or a combination thereof. The second layer is deposited on top of the first layer and comprises a rhodium component supported on a second refractory metal oxide component and a second palladium component supported on a second oxygen storage component, a third refractory metal oxide component or a combination thereof. Generally these catalyst composites are used as three-way conversion (TWC) catalysts. Methods of making and using the same are also provided.

Described are SCR catalyst systems comprising a first SCR catalyst composition and a second SCR catalyst composition arranged in the system, the first SCR catalyst composition promoting higher N.sub.2 formation and lower N.sub.2O formation than the second SCR catalyst composition, and the second SCR catalyst composition having a different composition than the first SCR catalyst composition, the second SCR catalyst composition promoting lower N.sub.2 formation and higher N.sub.2O formation than the first SCR catalyst composition. The SCR catalyst systems are useful in methods and systems to catalyze the reduction of nitrogen oxides in the presence of a reductant.

The present invention provides a method of treating an exhaust gas comprising methane and NO. The exhaust gas is contacted with a catalyst in the presence of oxygen to oxidize at least part of the methane in the gas stream to carbon dioxide and water and at least part of the NO into NO.sub.2 obtaining a treated gas stream. The catalyst comprises one or more noble metals supported on non-modified zirconia, wherein the zirconia comprises tetragonal zirconia and monoclinic zirconia, and wherein the weight ratio of tetragonal zirconia to monoclinic zirconia is in the range of from 1:1 to 31:1.

A composition of formula
Ce.sub.1-a-b-cN.sub.aM.sub.bD.sub.cO.sub.xI
wherein M stands for one or more elements from the group of alkaline metals, except sodium, N is Bi and/or Sb, D is present, or is not present, and if present is selected from one or more of Mg, Ca, Sr, Ba; Y, La, Pr, Nd, Sm, Gd, Er; Fe, Zr, Nb, Al; a is a number within the range of 0<a0.9, b is a number within the range of 0<b0.3, c is a number within the range of 0<c0.2, a plus b plus c is <1, and x is a number within the range of 1.2x2, and its use for exhaust gas aftertreatment systems of Diesel engines, gasoline combustion engines, lean burn engines and power plants.

The disclosure provides a system and a method for reducing hazardous gases, including PHGs, through one or more photocatalysts in a filter system. A microstructure of the photocatalytic filter can be formed using biological systems as a template for the photocatalysts to be deposited thereon. The biological system can be removed by heat, oxidation, or by chemical processes to leave the photocatalytic template as a filter for the gases. In various embodiments, multiple photocatalysts can be activated at different wavelengths to filter different gases, or multiple photocatalysts can be activated at the same wavelength to filter different gases, or a photocatalyst can be activated at different wavelengths to filter different gases, or some combination thereof. The activation can be sequential or concurrent. For multiple layers of photocatalysts, the sequence of the photocatalysts can be arranged to reduce damaging output from an upstream photocatalyst to one or more downstream photocatalysts.

A diesel oxidation catalyst, comprising a washcoat comprising four layers, the washcoat being disposed on a substrate, wherein the washcoat comprises a first layer comprising a first platinum group metal supported on a first metal oxide support material, which first layer is disposed on the substrate; a second layer comprising a second platinum group metal supported on a second metal oxide support material, and comprising a fifth platinum group metal, which second layer is disposed on the first layer; a third layer comprising a third platinum group metal supported on a third metal oxide support material and comprising a zeolitic material comprising Fe and comprising a sixth platinum group metal; and a fourth layer comprising a fourth platinum group metal and a fourth metal oxide; wherein the substrate has a length, a front end and a rear end; wherein the first layer is disposed on the substrate on the entire length of the substrate, wherein the second layer is disposed on the first layer on the entire length of the substrate; wherein the third layer is at least partially disposed on the second layer on x % of the length of the substrate from the front end of the substrate; wherein the fourth layer is at least partially disposed on the second layer on y % of the length of the substrate from the rear end of the substrate; wherein x is in the range of from 30 to 70, y is in the range of from 30 to 70 and x+y is in the range of from 95 to 115.

An inorganic oxide material doped with nano-rare earth oxide particles that is capable of trapping one or more of NO.sub.x or SO.sub.x at a temperature that is less than 400 C. The nano-rare earth oxide particles have a particle size that is less than 10 nanometers. The catalyst support can trap at least 0.5% NO.sub.2 at a temperature less than 350 C. and/or at least 0.4% SO.sub.2 at a temperature less than 325 C. The catalyst support can trap at least 0.5% NO.sub.2 and/or at least 0.2% SO.sub.2 at a temperature that is less than 250 C. after being aged at 800 C. for 16 hours in a 10% steam environment. The catalyst support exhibits at least a 25% increase in capacity for at least one of NO.sub.x or SO.sub.x trapping at a temperature that is less than 400 C. when compared to a conventional rare earth doped support in a 10% steam environment.