1781results about "Surface coverings" patented technology

Provided is an emission treatment system and method for simultaneously remediating the nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons present in diesel engine exhaust streams. The emission treatment system has an oxidation catalyst upstream of a soot filter coated with a material effective in the Selective Catalytic Reduction (SCR) of NOx by a reductant, e.g., ammonia. Also provided is a method for disposing an SCR catalyst composition on a wall flow monolith that provides adequate catalyst loading, but does not result in unsuitable back pressures in the exhaust.

Provided is an emissions treatment system and method for reducing NOx emissions in the exhaust stream produced from an internal combustion engine. The system has an injector for periodically metering ammonia or an ammonia precursor into an exhaust stream; and a first substrate with a first SCR catalyst composition, downstream of the injector. The first substrate has an inlet end, an outlet end, a length extending between the inlet end to the outlet end, wall elements and a plurality of passages defined by the wall elements. The first SCR catalyst composition is disposed on the wall elements from the inlet end toward the outlet end to a length that is less than the substrate's axial length to form an inlet zone. The first substrate also has an NH3 destruction catalyst composition with a platinum group metal component dispersed on a refractory metal oxide. The NH3 destruction catalyst is disposed on the wall elements from the outlet end toward the inlet end to a length that is less than the substrate's axial length to form an outlet zone. Generally, there is from 0.1 to 10 g / ft3 of platinum group metal component in the outlet zone.

The invention provides a catalyzed soot filter formed on a wall flow substrate having internal walls coated with catalyst compositions. The soot filter maintains a homogeneous flow of the exhaust gases through the internal walls of the substrate along the length of the filter due to the coating design. Both the efficiency and the durability of the catalytic function are increased over conventionally designed catalyzed soot filters. The catalyzed soot filter provides an integrated function for simultaneously treating the gaseous components of the exhaust (e.g., CO and HC) and the particulate matter deposited in the filter.

A filter, system and method is provided for filtering nanoparticles in a hot gas, namely particles <about 1 micron in a gas >about 200° C. and further particularly >about 450° C. including diesel exhaust. The filter includes filter media material composed of fibrous filter media having a plurality of fibers and granular filter media having a plurality of granules extending from the surfaces of the fibers. The filter is characterized by a permeability >about 3×10−12 m2 and an inertial resistance coefficient <about 1×106 m−1. The filter captures particles in the Most Penetrating Region (MPR). A filter system includes a nanoparticle filter in series with a diesel exhaust treatment element.

An object of the present invention is to provide a honeycomb filter for purifying exhaust gases that is free from a gap formed between a plug and a partition wall and cracks generated in the plug and a portion of the partition wall contacting the plug, and is superior in durability. The present invention provides a honeycomb filter for purifying exhaust gases which has a structure in which: a columnar body made of porous ceramic comprises a number of through holes, said through holes being placed in parallel with one another in the length direction with a wall portion interposed therebetween; predetermined through holes of said through holes are filled with plugs at one end of said columnar body, while the through holes that have not been filled with said plugs at said one end are filled with plugs at the other end of said columnar body; and a part or all of said wall portion functions as a filter for collecting particulates, wherein the porosity of the columnar body is in a range from 20 to 80%, and the porosity of the plug is 90% or less and is also set to 0.15 to 4.0 times as much as the porosity of the columnar body.

A honeycomb filter for purifying exhaust gases that is free from occurrence of cracks and coming-off of plugs and is superior in durability upon its use. The honeycomb filter includes a columnar body made of porous ceramics, which has a number of through holes placed in parallel with one another in the length direction with wall portion interposed therebetween, designed so that predetermined of the through holes are filled with plugs at one end of the columnar body, while the through holes not filled with the plugs at the one end are filled with plugs at the other end of the columnar body, and part of or the entire wall portion functions as a plug for collecting particles. A bending strength Fα (MPa) of the honeycomb filter and a length L (mm) of the plug in the length direction of the through hole satisfy the relationship of Fα×L≧30.

A diesel engine exhaust treatment system and method is provided which utilizes a diesel particulate filter positioned in the exhaust gas stream of a vehicle which includes an SCR catalyst, an ammonia oxidation catalyst, and / or a diesel oxidation catalyst. The system is capable of performing multiple functions including converting NOx to N2, converting HC and CO to H2O and CO2, trapping particulates, and minimizing ammonia emissions. The system is more compact and efficient than prior systems utilizing separate catalyst units, and minimizes backpressure while maximizing catalyst performance.

Catalysts and catalytic articles for treating exhaust gas streams are described. In one or more embodiments, a catalyst system includes a first zone to abate nitrogen oxides by selective catalytic reduction, a second zone to oxidize ammonia and a third zone to oxidize carbon monoxide and hydrocarbons. Methods for treating the exhaust gas stream are also provided. Methods of making and using such catalysts and catalytic articles are also described.

One concept of the inventors relates to a system and method in which a particulate filter comprises at least about 40% by weight of an NOx adsorbant. The filter can be used as both an NOx trap and a particulate filter. By constructing the filter elements using a substantial amount of NOx adsorbant, a large volume of NOx adsorbant can be incorporated into the particulate filter, which substantially reduces the volume and expense of an exhaust system that includes both a catalytic diesel particulate filter and an NOx trap having a large quantity of NOx adsorbant. In a preferred embodiment, the filter also oxidizes NO to NO2. In another preferred embodiment, an SCR catalyst is position downstream of the filter elements.

It is to provide a filter for an exhaust gas having a high thermal conductivity irrespective of a relatively high porosity or showing characteristics that the whole of the filter containing a high refractive index substance or pigment is easily warmed but hardly cooled while making low the thermal conductivity of the filter as a whole. This filter is provided with a catalyst coat layer formed by carrying a catalyst active component on a surface of a porous ceramic carrier, in which a porosity of the porous ceramic carrier is 40-80% and a substance or a pigment indicating a thermal conductivity as the filter of 3-60 W / mk or having a large refractive index at a thermal conductivity of 0.3-3 W / mk.

A layered, three-way conversion catalyst having the capability of simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides is disclosed. In one or more embodiments, the catalyst comprises three layers in conjunction with a carrier: a first layer deposited on the carrier and comprising palladium deposited on a refractory metal oxide and an oxygen storage component; a second layer deposited on the first layer and comprising rhodium deposited on a refractory metal oxide and an oxygen storage component; and a third layer deposited on the second layer and comprising palladium deposited on a refractory metal oxide.

An exhaust treatment system includes an oxidation device having a plurality of channels through which a flow of exhaust flows. A first portion of the channels of the oxidation device are coated with catalytic material for converting NO to NO2 and a second portion of the channels are uncoated with the catalytic material. The exhaust treatment system also includes a selective catalytic reduction device disposed downstream from the oxidation device. The selective catalytic reduction device is configured to receive the flow of exhaust passing through the oxidation device.

This invention relates generally to uses of novel nanomaterial composition and the systems in which they are used, and more particularly to nanomaterial compositions generally comprising carbon and a metal, which composition can be exposed to pulsed emissions to react, activate, combine, or sinter the nanomaterial composition. The nanomaterial compositions can alternatively be utilized at ambient temperature or under other means to cause such reaction, activation, combination, or sintering to occur.

A diesel engine exhaust treatment system and method is provided which includes a platinum group metal trapping device positioned between a diesel oxidation catalyst and an SCR catalyst. The platinum group metal trapping device traps trace amounts of platinum group metals which may be released from the diesel oxidation catalyst during engine operation and prevents them from accumulating on the SCR catalyst, preventing potential contamination of the SCR catalyst as well as ensuring that the performance of the SCR catalyst is uninhibited.

The present invention is directed to an exhaust gas treatment system and method for removing particulate matter and nitrogen oxides from diesel engine exhaust streams. More specifically, the present invention relates to an emission treatment system that effectively provides simultaneous treatment of the particulate matter, as well as the NOx and other gaseous components of diesel engine exhaust. The emission treatment system uses an integrated soot filter coated with a catalyst washcoat composition comprising sub-micron particles, thereby providing an ultra-thin sub-micron washcoat layer showing improved catalyst performance without causing excessive backpressure.

An engine exhaust catalyst exhibits improved CO oxidation performance relative to conventional engine exhaust catalysts and includes a first supported catalyst comprising platinum and a second supported catalyst comprising palladium and gold species in close contact. The first supported catalyst may be a platinum catalyst, a platinum—palladium catalyst, or a platinum catalyst promoted with bismuth, and the second supported catalyst preferably has a palladium to gold weight ratio of about 0.85:1.0. To improve aged catalyst performance, the first and second supported catalysts are coated onto different layers, zones, or monoliths of the substrate for the engine exhaust catalyst.

Provided is a base metal undercoat containing catalyst and an exhaust article containing the catalyst. The catalyst contains a base metal undercoat with an oxygen storage component, and at least one catalytic layer. Also provided are methods for preparing the catalyst and methods for monitoring the oxygen storage capacity of an exhaust article containing the catalyst.

A honeycomb filter comprises a honeycomb structure having a large number of through channels formed in the axial direction and partitioned by porous partition walls, wherein specified through channels are plugged only on one end face at the same side out of two end faces. This honeycomb filter shows less pressure loss, and is hardly clogged with solids that cannot be extinguished by combustion such as ash, iron oxide, and the like. Furthermore, an unwanted discharge of particulates deposited in through channels of the filter in a larger amount due to pulsation even under conditions that the exhaust gas from an engine greatly pulsates can be effectively suppressed. This filter is also usable as an element for exhaust gas purification system, or a part of composite filter in addition to the use for an exhaust gas purification filter for gasoline engines. The production method therefor is also disclosed.

The invention provides low temperature NO2 trap compositions useful for adsorbing NO2 from a gas stream at lower temperatures, and releasing the NO2 at higher temperatures. The low temperature trap compositions are useful for incorporation into a diesel exhaust system equipped with a soot filter. The NO2 from the diesel exhaust can be stored when the exhaust temperature is cool, e.g., during startup and at times of low load, and released when the exhaust is at higher temperatures. The released NO2 serves as an effective oxidant for the combustion of soot deposited on the soot filter. These temperatures are significantly lower than those required for the combustion of soot using O2 as an oxidant. The methods of the invention thereby provide a method for regenerating the soot filter within operating temperature ranges typical of diesel engine exhaust systems.

Provided is an SCRF article having different SCR catalysts compositions disposed on a wall-flow filter substrate in zones that are arranged in series with respect to the inlet and outlet faces of the substrate. Also provided is method of reducing backpressure and ammonia slip that involves the use of such SCRF articles.

An emission control catalyst that exhibits improved CO and HC reduction performance includes a supported platinum-based catalyst, and a supported palladium-gold catalyst. The two catalysts are coated onto different layers, zones, or monoliths of the substrate for the emission control catalyst such that the platinum-based catalyst encounters the exhaust stream before the palladium-gold catalyst. Zeolite may be added to the emission control catalyst as a hydrocarbon absorbing component to boost the oxidation activity of the palladium-gold catalyst.

A catalyzed diesel particulate filter (CDPF) and a method for filtering particulates from diesel engine exhaust are provided, where the catalyzed diesel particulate filter includes a substrate and a catalyst composition, where the catalyst composition contains at least one first component, at least one second component, and at least one third component, where the first component is at least one first component selected from the group consisting of cerium and a lanthanide and mixtures thereof, the at least one second component is selected from the group consisting of cobalt, copper, manganese and mixtures thereof; and the third component comprises strontium, where the first component, the second component, and the third component are in an oxide form after calcination. The catalyst on the catalyzed diesel particulate filter lowers the temperature at which particulates are removed from the CDPF by oxidizing the particulates on the filter. The catalyzed diesel particulate filter may also include a washcoat. Washcoats prepared from colloidal aluminum oxide may have higher surface areas and pore volumes loadings than washcoats containing aluminum oxide prepared from aluminum nitrate.

The invention provides a catalyzed soot filter formed on a wall flow substrate having internal walls coated with catalyst compositions. The soot filter maintains a homogeneous flow of the exhaust gases through the internal walls of the substrate along the length of the filter due to the coating design. Both the efficiency and the durability of the catalytic function are increased over conventionally designed catalyzed soot filters. The catalyzed soot filter provides an integrated function for simultaneously treating the gaseous components of the exhaust (e.g., CO and HC) and the particulate matter deposited in the filter.

A multi-layer emission control catalyst exhibits improved CO and HC reduction performance. The bottom layer includes a supported catalyst comprising platinum and palladium particles or palladium and gold particles. The middle layer includes zeolites. The top layer includes a supported catalyst comprising platinum and palladium particles. The use of zeolite mixture in the middle layer further improves CO and HC reduction performance in comparison with using zeolite of a single type. The use of a supported catalyst comprising palladium and gold particles in the bottom layer further improves CO and HC reduction performance in comparison with using a supported catalyst comprising platinum and palladium particles.

An exhaust gas purifying catalyst is constructed by laminating sequentially a first layer containing alumina, a second layer containing hydrocarbon adsorbent, and a third layer containing catalytic components on a monolithic support in which a cell sectional shape is a polygon. The second layer has a ratio Lmax / Lmin of a thickest portion (Lmax) at cell corner portions to a thinnest portion (Lmin) at cell flat portions in a range of 1 to 10, and has a thickness of 10 to 500 mum. The catalyst can achieve the purification of HC, CO, and NOx with good balance, and improve the purification performance of cold HC by controlling a diffusion speed of the exhaust gases that pass through cells in a support and diffuse into a coating layer.

Zoned diesel oxidation catalysts containing a higher precious metal loading in the inlet zone that the outlet zone and an equal or shorter length inlet zone are described. Emission treatment systems and methods of remediating nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons using zoned diesel oxidation catalysts are also described.

Systems and methods are provided for a layered emission control device coupled to an exhaust manifold. Various formulations may be incorporated in a plurality of layers of the device to enable various emission control functions to be grouped within spatial constraints. The layers may be organized to reduce functional interference and improve functional synergy between the various emission control functions.

An oxidation catalyst deposited on a filter substrate for the removal of CO, hydrocarbons, and particulate matter, such as soot, from an exhaust stream wherein the oxidation catalyst is formed from a platinum group metal supported on a refractory oxide, tin oxide, and a zeolite.