Abstract: An oxidation catalyst for a light-duty diesel vehicle comprising a first upstream part (2) and a second downstream part (3) of high heat capacity relative to the first part, each part comprising a substrate and a catalyst support coated thereon. With this arrangement the diesel catalyst can reach light-off temperature more quickly and retain sufficient heat to maintain light-off temperature for substantially longer than conventional diesel catalyst arrangements.

Abstract: An improved catalyst system that includes a metal support structure and an anti-corrosive layer on the metal support structure, and has improved resistance to corrosion and other degradation under corrosive environments. Typically, a catalyst supporting layer is applied over the anti-corrosive layer.

Abstract: The invention provides alumina agglomerates of the type obtained by dehydrating an aluminum hydroxide or oxyhydroxide, agglomerating the alumina obtained, hydrothermally treating the agglomerates and calcining. The invention also provides a catalyst support, an adsorbent material and a catalyst constituted by said agglomerates. The invention also provides methods for preparing said agglomerates.

Abstract: Porous ceramic catalyst supports or filters to be provided with catalyst coatings via oxide washcoating processes are pre-coated with cross-linked polymer barrier layers to prevent washcoat nanoparticle intrusion into the microcracked and/or microporous surfaces of the ceramics, the barrier coatings being formed by thermally cross-linking hydrocarbon polymers that are vaporizable at moderate washcoat stabilization or catalyst activation temperatures and being preferentially.

Abstract: A catalyst carrier which comprises particles of a silicon-containing ceramic material. Each of these particles is covered by a film of alumina on which a noble metal is carried.

Abstract: The invention relates to alumina agglomerates of the type obtained by dehydrating an aluminium oxyhydroxide or hydroxide, agglomerating the alumina thus obtained, hydrothermally treating the agglomerates and calcinating same. Said agglomerates are characterised in that: the V37 ? thereof is greater than or equal to 75 ml/100 g, preferably greater than or equal to 80 ml/100 g and, better still, greater than or equal to 85 ml/100 g; the V0.1 ?m thereof is less than or equal to 31 ml/100 g; and the V0.2 ?m thereof is less than or equal to 20 ml/100 g, preferably less than or equal to 15 ml/100 g and, better still, less than or equal to 10 ml/100 g. The invention also relates to a catalyst carrier, an intrinsic catalyst or an absorbent, in particular for use in the petroleum and petrochemical industry, comprising such alumina agglomerates. Moreover, the invention relates to methods for preparing said agglomerates.

Abstract: This invention provides a method for producing a ceramic catalyst body that can directly support a catalyst on a ceramic support without disposing a coating layer on the ceramic support. In the invention, a catalyst solution containing a catalyst component consisting of a negative complex ion resulting from a catalyst precursor is prepared, and a pH of the catalyst solution is adjusted in such a manner as to satisfy the relation E1>E2 and E1>0 where E1 is a surface potential of a matrix phase consisting of a cordierite-W composite body relative to the pH of the catalyst solution and E2 is a surface potential of a dispersed phase consisting of compounds other than the cordierite-W composite body. After the ceramic support is brought into contact with the catalyst solution to support the catalyst component, heat-treatment is conducted to bond the matrix phase consisting of the cordierite-W composite body and the catalyst component to support the catalyst on the ceramic support.

Abstract: A honeycomb structure 1 has a large number of through-holes 3 divided by partition walls 2 and extending in the axial direction, characterized in that the honeycomb structure contains a Si phase having a lattice constant controlled at 0.54302 to 0.54311 nm at room temperature. A process for producing the honeycomb structure 1, includes a firing step of firing a precursor of honeycomb structure, wherein the precursor contains a Si phase and the firing step is conducted using a furnace material free from any boron-containing compound. A process for producing the honeycomb structure 1, includes a firing step of firing a precursor of honeycomb structure, wherein a reduction percentage of Si content in Si phase after firing step relative to Si content in Si phase before firing step is suppressed at 10% by mass or less. Having an improved thermal conductivity, the honeycomb structure is superior in thermal shock resistance.

Abstract: A filtering method including the steps of preparing a water purifying apparatus 1 with a cell structure 2 having units for constituting cell structure 4, and a cap portion 3, and making raw water flow into cells 10 from one end, and filtered by a partition walls 9 to take out filtrate water from the side of an outer peripheral surface 8. The cell structure 2 is so constructed that the ratio of maximum value to minimum value in water permeability among the partition walls 9 provided therein is within a range from of 110 to 300% in terms of percentage, and the cells 10 located on the side of an outer periphery 7 of the cell structure 2 have a greater water permeability.

Abstract: An exhaust gas purifying catalyst including a carrier having a plurality of cells as exhaust gas passages, an HC adsorbent layer formed on the carrier of each of the cells, and an upper catalyst layer disposed on an upstream side of each of the exhaust gas passages on the HC adsorbent layer and a lower catalyst layer disposed on a downstream side of each of the exhaust gas passages on the HC adsorbent layer. The upper catalyst layer includes more O2-storage material than the lower catalyst layer, and the lower catalyst layer includes a catalyst having a wider activation range than the upper catalyst layer.

Abstract: It is to provide a catalyst carrier having large pore size and porosity and a small pressure loss. The catalyst carrier is characterized by covering a surface of each particle in a silicon-containing ceramic carrier with alumina thin film, and is produced by immersing a carrier having an oxide film of a silicide in its surface in a solution of aluminum containing metal compound, drying by heating, calcining, subjecting to an immersion treatment in hot water and thereafter firing.

Abstract: The invention provides a monolithic catalyst support for hydrogenation and hydrotreating and in particular for selective hydrogenation of pyrolysis gasoline. The monolithic catalyst includes (i) a multicellular monolith body, preferably having a honeycomb structure, most preferably a honeycomb structure made of cordierite, the honeycomb structure having an inlet end, an outlet end, and a multiplicity of mutually adjoining cells extending along the length of the body from the inlet end to the outlet end, the cells being separated from one another by porous walls, and, (ii) a coating consisting of theta alumina synthesized in situ on the multicellular monolith body. The in situ theta alumina is strongly bonded with the multicellular monolith body and comprises at least 50% by weight of the washcoat layer, and preferably greater than 90% by weight.

Abstract: The present invention provides an exhaust gas purifying filter that has an increased contact area, between a catalyst supported on the dividing walls of a honeycomb structural body and particulate matter deposited thereon, and can improve the capacity of the catalyst to oxidize the particulate matter, and a method of manufacturing the same. According to the present invention, the exhaust gas purifying filter 1 comprising the honeycomb structural body 10 made of ceramic and the catalyst 2 supported on the surface of the dividing walls 11 of the honeycomb structural body 10 has void ratio, of the dividing wall 11 of the honeycomb structural body 10, in a range from 55 to 80%, and the proportion of surface pores is 20% or higher.

Abstract: Monolithic metallic catalyst substrates offering improved heat conductivity are provided from metal powder extrusion batches of copper, tin, zinc, aluminum, iron, silver, nickel, and mixtures and alloys thereof by extrusion through a honeycomb extrusion die followed by drying and firing in a two stage firing process to oxidize organic extrusion batch components, remove residual oxides from the porous wall structure, and consolidate the metal powders to strong, integral honeycomb support structures.

Abstract: The invention is directed at a mullite-aluminum titanate porous diesel particulate filter constituting a porous ceramic body containing, expressed in terms of weight percent of the total body, of 60-90%, preferably 70-80%, most preferably 70% iron-aluminum titanate solid solution having a stoichiometry of Al2(1?x)Fe2xTiO5, where x is 0-0.1, and 10-40%, preferably 20-30%, most preferably 30% mullite (3Al2O3.2SiO2), and consists essentially, expressed in terms of weigh percent on the oxide basis, of 3 to 15% SiO2, 55 to 65% Al2O3, 22 to 40% TiO2, and 0 to 10% Fe2O3, and being useful for filtration of diesel exhaust. The inventive diesel particulate filter exhibits high interconnected open porosity and large median pore size, in combination with high permeability when fired to a temperature of between 1650° to 1700° C., along with high thermal shock resistance and good filtration capability.

Abstract: A honeycomb structure which includes an inlet end and an outlet end opposing each other and a plurality of cell channels extending along an axis from the inlet end to the outlet end, the cell channels having non-equal, square cross-sections, and an extrusion die for making the same.

Abstract: Bulk and supported catalysts are prepared from an aqueous slurry containing a catalytically active material and a binder. The slurry is either coated onto a support and dried to form a porous, high surface area phase containing the catalytically active material, or reduced to a paste-like consistency, molded and dried to form a bulk catalyst. The processes and catalysts may be employed in various catalytic chemical processes to achieve high effectiveness factor of the catalytically active material while achieving a lower pressure drop.

Abstract: The present invention relates to an apparatus for producing a honeycomb body, which comprises a roll part for supplying a thin metal flat sheet via several rolls; a part for measuring the length of feed of the flat sheet which is fed through said roll part for supplying a flat sheet; a roll part for supplying a corrugated sheet to overlap the same onto said flat sheet via several rolls; a winding roll of a honeycomb body which is made by folding the overlapping flat and corrugated sheets in feed into a roll; a part for measuring the rotation angle of said winding roll; and a control part, which is connected respectively to said part for measuring the length and said part for measuring the rotation angle, wherein said control part controls the amount of winding of a honeycomb body by receiving and computing the measurement values therefrom.

Abstract: Compositions, articles and methods for making such articles are disclosed. The compositions, articles and methods include calcium aluminate materials having a low coefficient of thermal expansion.

Abstract: A honeycomb filter is composed mainly of silicon carbide or of metallic silicon and silicon carbide; the filter being formed by bonding a plurality of honeycomb segments each of which has a plurality of through-holes being partitioned by porous partition walls. The filter is plugged alternately at the exhaust gas inlet face and exhaust gas outlet face of honeycomb segments. Each two adjacent honeycomb segments are contacted with each other at each a portion of their sides facing each other. They are bonded with each other at least at part of each portion of said sides other than the contacted portion through a bonding material having a strength lower than that of a basal body of honeycomb segment. Thus, the thermal stresses generated among the respective portions constituting the filter is reduced. The generation of cracks, etc. can be also prevented considerably.

Abstract: The invention relates to a honeycomb (14), particularly a catalytic converter substrate, with a honeycomb structure comprising a large number of ducts (16) running in the longitudinal direction of the honeycomb, through which a fluid can flow, where the honeycomb possesses foil layers (15) arranged one above the other. In order to create a honeycomb permitting high efficiency of the catalytic conversion reactions with low thermal inertia, as well as inexpensive manufacture, it is proposed to provide ducts (16) whose cross-sectional dimension in a first direction is several times the cross-sectional dimension in another direction. In particular, the ducts can extend over the entire width of the honeycomb. In order to stabilise the honeycomb, stiffening elements (19, 20) can be provided, which are either integrated in the foil layers or separate (FIG. 3).

Abstract: A catalyst carrier having a circular cell honeycomb structure formed from a plurality of cell passages whose inner surfaces are substantially circular and are coated with a catalyst for oxidizing and/or deoxidizing exhaust gas of a vehicle, wherein the circular-cross-section cells are integrally formed with the catalyst carrier by extrusion. The catalyst carrier allows the catalyst layer to be uniformly coated on the inner surface of the cell while reducing the amount of catalyst consisting of precious metals, and the cell-density can be increased by minimizing the height between the centers of the cells vertically disposed.

Abstract: A honeycomb body includes layered or wound sheet-metal layers at least partially structured to form passages through which exhaust gas can flow. The sheet-metal layers are formed of a special steel with 15 to 25% chromium, typical rare earths necessary for resistance to corrosion at high temperatures and an aluminum content of between 1 and 4.5%. Such a honeycomb body with sheet-metal layers having a thickness of more than 0.06 mm, preferably 0.01 to 0.12 mm, is suitable as a catalyst carrier body for the emission control systems of two-wheeled vehicles or motorcycles, despite its low aluminum content. Sheet-metal layers of this type are even suitable for use in the emission control systems of diesel vehicles with lower thicknesses since the temperatures are lower in these systems, in general below 800° C. Sheet-metal layers containing between 1 and 4.5% aluminum can be derived from other production processes before the aluminum content is increased with additional procedures.

Abstract: A channelized sorbent material comprises porous sorbent particles characterized by an average pore diameter. Each sorbent particle has at least one interior channel of an average transverse dimension (i.e. transverse diameter) that is at least ten times larger than the average pore diameter of the porous sorbent particle. The interior channel may constitute a single cylindrical through-bore in the sorbent particle, or alternatively, an array of intersecting or non-intersecting channels. The porous sorbent particles preferably comprise bead activated carbon particles. Such channelized sorbent material is particular useful as sorbent media in an adsorption-desorption apparatus for storage and dispensing of a sorbable fluid.

Abstract: The present invention provides a ceramic honeycomb structural body, and method for preparing the same, which can satisfactorily support a catalyst and can demonstrate superior mechanical strength, even if far thinner walls are used. Said structural body comprises lattice walls formed by a large number of cells 10 which are channels for a fluid and a peripheral wall 12 which covers at least the circumference of said lattice walls 11.

Abstract: A honeycomb structure 1 formed by bonding into one piece, via a bonding layer 8, a plurality of honeycomb segments 12, the honeycomb segment having an outer wall 7, partition walls 2 provided inside the outer wall, and a large number of through-holes 3 divided by the partition walls 2 and extending in the axial direction of the segment is provided.

Abstract: A purification catalyst for exhaust gas is provided that uses a hexagonal cell monolithic carrier which is able to demonstrate purification performance that is superior to the case of using a square cell monolithic carrier. This purification catalyst for exhaust gas comprises a monolithic carrier (10) provided with hexagonal cells (15) of 200 cells/in2 or more in which the porosity of partition walls (11) that form the cells (15) is 25% or more; and, a catalyst layer (2) arranged on the surface of the partition walls (11) of the monolithic carrier (10) that contains a catalyst component for purification of exhaust gas. The thickness of catalyst layer (2) is 10-70 &mgr;m at its thin portion (21), and its thick portion (22) has a thickness of no more than 12 times that of thin portion (21).

Abstract: A honeycomb body made from a ceramic material with improved radial pressure resistance that is of cylindrical shape and features a first and a second end face and a cylindrical shell and that is traversed from one end face to the other by axially parallel channels formed by channel walls and distributed across the cross section of the honeycomb body in a regular grid pattern, in which design an outer marginal zone of the honeycomb body, the thickness of which amounts to several channel diameters, encloses a central area. The increase in radial pressure resistance of the honeycomb body is achieved by reinforcing the ceramic material of the cylindrical shell and of the channel walls in the outer marginal zone of the honeycomb body by depositing on or in it one or several inorganic substances for the purpose of increasing its mechanical stability.

Abstract: An improved heterogeneous catalyst for catalyzing the reaction of gaseous reactants, comprising a high performance catalyst particle with a diameter to height ratio in the range between about 0.5:1 to 1.0:1.0, the high performance catalyst particle has a Relative Particle Size Parameter (RPSP) and a Geometric Surface Area (GSA), wherein the high performance catalyst particle has a higher GSA for a particular RPSP than a prior art catalyst particle. In another embodiment the improved heterogeneous catalyst with a diameter to height ratio in the range between about 0.5:1 to 1.0:1.0 has a Relative Particle Size Parameter (RPSP), a Geometric Surface Area (GSA), and an associated Relative Pressure Drop (RPD), wherein the high performance catalyst particle has a higher GSA for a particular RPSP or alternately a lower RPD for a particular GSA than a prior art catalyst particle.

Abstract: A pliable refractory metal carrier (46) may have coated thereon an anchor layer (47) to improve adherence to the carrier (46) of a catalytic coating (48). The conformable catalyst member (26, 82, 82′, 126, 226, 326) may be bent to conform to a curved or bent exhaust pipe (20, 220, 320) within which it is mounted. The pliable metal carrier may be in the form of a tube such as carrier (46) having perforations (54) formed therein, or it may be a metal strip (76) which is folded into accordion pleats (80) and has perforations (78) formed therein. The perforations (54, 78) serve to permit the passage of exhaust gas therethrough. A series of interior closures (58) and annular baffles (60) may be provided to import a serpentine flow path to gases flowed through an exhaust pipe (22) containing a conformable catalyst member (226) therein. A mounting member (68) may be supplied to fasten one end of the conformable catalyst member (226) to the discharge end of an exhaust pipe (220).

Abstract: A honeycomb structure which includes an inlet end and an outlet end opposing each other and a plurality of cell channels extending along an axis from the inlet end to the outlet end, the cell channels having non-equal, square cross-sections, and an extrusion die for making the same.

Abstract: The invention is directed at a mullite-aluminum titanate porous diesel particulate filter constituting a porous ceramic body containing, expressed in terms of weight percent of the total body, of 60-90%, preferably 70-80%, most preferably 70% iron-aluminum titanate solid solution having a stoichiometry of Al2(1−x)Fe2xTiO5, where x is 0-0.1, and 10-40%, preferably 20-30%, most preferably 30% mullite (3Al2O3.2SiO2), and consists essentially, expressed in terms of weigh percent on the oxide basis, of 3 to 15% SiO2, 55 to 65% Al2O3, 22 to 40% TiO2, and 0 to 10% Fe2O3, and being useful for filtration of diesel exhaust. The inventive diesel particulate filter exhibits high interconnected open porosity and large median pore size, in combination with high permeability when fired to a temperature of between 1650° to 1700° C., along with high thermal shock resistance and good filtration capability.

Abstract: A ceramic support element for a NOx trap which includes a NOx storage component comprising an alkali metal, the ceramic support having a composition lying within a ternary system selected from the group consisting of Al2TiO5—MgTi2O5—MgAl2O4 and Al2TiO5—FeTiO5—Al2O3, a coefficent of thermal expansion (22-800° C.) of less than 20×10−7/° C. and a modulus of rupture as measured on a solid rod of circular cross section of greater than 1000 pounds per square inch.

Abstract: A ceramic honeycomb structure (1) constituted by cell walls (ribs) (2) forming a composite structure from a plurality of cells (3) being adjacent each other and a honeycomb outer wall (4) surrounding and holding the outermost peripheral cells located at the circumference of the composite structure; said composite structure satisfying the followings: the basic thickness of the cell walls (2) (the basic cell wall thickness) (Tc) is Tc≦0.12 mm, the outer wall thickness (Ts) of the honeycomb structure is Ts≧0.05 mm, and the open frontal area (P) is P≧80%, and there is a relation shown by formula: 1.10≦(Tr1˜Tr3-20)/Tc≦3.00 between the basic cell wall thickness (Tc) and each cell wall thickness (Tr1˜Tr3-20) of cells existing between an outermost peripheral cell and any cell within a first end cell from a third cell to a twentieth cell extending inwardly, taking the outermost peripheral cell as a first starting cell.

Abstract: A monolith for imparting swirl to a gas stream includes a stack of alternating flat and corrugated strips defining channels for gas flow. The strips are attached, at an angle, to a carrier. Also, the corrugations of the corrugated strips may be skewed. The carrier defines a cylindrical shell for the strips, and the strips extend from the carrier to a central region. The strips are curved, typically having substantially the shape of involutes, and substantially fill the space between the central region and the shell. Due to the angle of attachment between the strips and the carrier, the gas flow channels are oriented in different directions, at different locations on the outlet face of the monolith. This structure therefore imparts swirl to gas flowing through the monolith.

Abstract: A ceramic carrier and ceramic catalyst body used as NOx purification catalysts for lean burn engines, which are inexpensive, exhibit high temperature durability and can maintain their catalytic function for extended periods. The ceramic carrier has a diffusion-inhibiting layer formed on the surface of a cordierite honeycomb structure, to inhibit diffusion of alkali metals, alkaline earth metals, etc. carried as NOx storage materials. The diffusion-inhibiting layer is composed of a ceramic material such as Y2O3, NiO or CeO2 which does not react with alkali metals or alkaline earth metals at temperatures of up to 1000° C. and has a melting point of higher than 1000° C., and the diffusion-inhibiting layer inhibits diffusion of catalyst components such as potassium into the interior to prevent their reaction with cordierite, so that the durability is greatly enhanced without reducing catalytic performance.

Abstract: A titania-coated honeycomb catalyst matrix is provided for the ultraviolet-photocatalytic oxidation of organic pollutants in a flowing fluid. A honeycomb-shaped skeletal structure (12) has a thin, lightweight substrate (18) of metal or ceramic, typically an aluminum alloy, and a surface coating (20) of photocatalyst, such as titania. The photocatalyst (20) is bonded to the substrate (18) via a thin oxide layer (18′) on the substrate. The oxide layer (18′) may be grown on the substrate. The photocatalyst coating (20) is made by mixing (30) titania powder in a TiO2 sol-gel to form a titania slurry. The substrate with oxide layer is coated (30) with the titania slurry and then heat treated (31). The photocatalyst coating (20) is typically applied to substrate sheets (40, 60, 62) preformed for assembly into a honeycomb-shaped skeletal structure (12) having an array of parallel cells (46, 46′).

Abstract: An improved metal catalytic tube includes an elongated metal member formed at least partially of metal particles and including a catalytic enhancement incorporated into the metal member. The metal member is formed with a cavity and includes an inner surface defined by the cavity and an outer surface opposite the inner surface. The metal member has a porosity at the outer surface that is greater than the porosity at the inner surface. The porosity at the inner surface is sufficiently low that the metal member can carry a quantity of gas through the cavity without the gas leaking through the inner surface of the metal member. The abstract shall not be used for interpreting the scope of the claims.

Abstract: Active carbon catalyst for recovering and removing sulfur oxides contained in flue gas by turning them into sulfuric acid by a catalytic desulfurization reaction. Powdery active carbon and fluororesin are kneaded by shearing force before being molded to a desired profile so that the inter-particulate gaps of powdery active carbon particles are made water-repellent. Flue gas preferably flows downwardly through a tower filled with such an active carbon catalyst, which is made to show a honeycomb structure having surfaces running only in a direction parallel to the flow. The activity of the catalyst maintains an enhanced level if dilute sulfuric acid or water is introduced into the active carbon from the top of the tower to cleanse the surface of the active carbon catalyst so that the catalyst layer is prevented from being clogged and contaminated by ashes and soot contained in flue gas.

Abstract: A honeycomb structure constituted by

Abstract: The invention provides a metal honeycomb core body used as the principal structural element of an exhaust gas cleaning unit excellent in various performances and economy that is provided with a corrugated band member, that is a structural member of a metal honeycomb core body having a special waveform structure. The invention provides a metal honeycomb core body having honeycomb structure fabricated by bringing corrugated band members (1) and planar band members (2) made of thin-walled metal sheet alternately into contact. The corrugated band member (1) has a waveform structure obtained by using a waveform of an imaginary corrugated sheet (1′) having crests and troughs which are in contact with a planar band member (2) and composed of a connected waveform having a desired waveheight (h) and one period length (&lgr;′).

Abstract: An exhaust gas purifying catalyst has an Ir powder. The Ir powder has a two peak particle size distribution, with a peak in a particle size D>25 nm region, and the other peak in a particle size D<25 nm region, respectively.

Abstract: A honeycomb structure which includes an inlet end and an outlet end opposing each other and a plurality of cell channels extending along an axis from the inlet end to the outlet end, the cell channels having non-equal, square cross-sections, and an extrusion die for making the same.

Abstract: A molding (catalyst structure) for chemical apparatuses which is formed from at least two closed frames and one or more cross-pieces connecting these frames, where the frames are arranged at a distance from one another in a single plane or in a plurality of parallel planes about an (imaginary) molding (structure) axis which is perpendicular to the plane(s) and passes through the center points of the frames. The molding (catalyst structure) is preferably formed from at least four closed frames and one or more cross-pieces connecting these frames, where the frames are arranged one inside the other at a distance from one another in at least two parallel planes about an (imaginary) molding (structure) axis which is perpendicular to the planes and passes through the center points of the frames, and each plane has at least two frames.

Abstract: The present invention relates to monolith catalysts comprising a catalytic metal deposited onto a coated monolith substrate comprising a wash coat applied to a monolith substrate wherein the monolith catalysts have a surface area ranging from 0.1 to 25 m2/gram as measured by adsorption of N2 or Kr using the BET method. The invention also relates to the coated monolith substrates used in such monolith catalysts. The monolith catalysts of the present invention are particularly suited toward use in hydrogenation processes which employ an immiscible mixture of an organic reactant in water.

Abstract: An apparatus for producing hydrogen from hydrocarbons or alcohol, particularly methanol, by feeding a reaction mixture comprising a hydrocarbon or alcohol and water onto a catalyst. The catalyst is formed by compressing at least one catalyst powder into a compressed layer to form a shaped body. The reaction mixture flows under pressure through the catalyst layer while the pressure drops. Furthermore, the apparatus is suitable for a use in a hydrogen shift phases for reducing carbon monoxide, in carbon monoxide oxidizers and catalytic burners. A process for producing the catalyst is also disclosed.

Abstract: A catalytic converter assembly for an exhaust gas system of an internal combustion engine, in particular for a small engine. The catalytic converter assembly has a housing and a catalytic converter formed of at most two layers formed of sheets disposed in the housing. The catalytic converter has an at least partially curved elongated body and at least one structured sheet with a structuring and a catalytically active material. The at least one structured sheet is wound on inclinedly around the elongated body and at least partially bears against the housing. The structuring of the at least one structured sheet in addition with one of the housing and a sheet of a layer of the at most two layers define closed passages there-between through which exhaust gases can flow and such that, as considered over the cross-section of the housing, a cross-sectional area bordered in by the closed passages constitutes at least half of a total of the cross-sectional area of the housing.

Abstract: A monolithic catalyst with micro-scale flow channels and methods of making such a monolithic catalyst are provided. The monolithic catalyst includes a plurality of thin catalyst walls. The walls have a set thickness in a range from 1 to 150 &mgr;m. The thin catalyst walls define a plurality of flow channels. A fugitive material is used to form the flow channels. The flow channels have a set width in a range from 1 to 200 &mgr;m. A flexible strip that includes a layer of catalyst material and a fugitive layer forms the monolithic catalyst. This flexibility allows the strips to be formed into selected shapes as needed for a particular reactor design. For example, strips can be rolled into a spiral cylinder or folded into a planar stack. The flow channels are formed by an organic fugitive material, which burns off during processing.

Abstract: A configuration for decomposing nitrogen oxides in a gas stream includes a plurality of catalytic converters disposed one after the other through which the gas stream can flow. Each of the catalytic converters has a honeycomb structure with many parallel cells through which the gas stream can flow. Each of the catalytic converters also has a predetermined cell density and a predetermined average level of activity defined as a proportion by weight of the catalytically active agent. The predetermined cell density of a second catalytic converter through which the gas stream flows after a first catalytic converter is lower than the predetermined cell density of the first catalytic converter. The predetermined average level of activity of the second catalytic converter is also higher than the predetermined average level of activity of the first catalytic converter. The configuration is preferably used in conjunction with an exhaust gas from a combustion drive unit.

Abstract: A metal catalyst carrier body includes layers of first and second metal sheets defining passages through which exhaust gases flow. The first metal sheet is corrugated and engaged with the second metal sheet in each of upstream and downstream regions at numeral contact points. In intermediate region between the upstream and downstream regions, the first metal sheet is out of engagement with the second metal sheet.