The present invention relates to a catalyst comprising a carrier substrate of the length L extending between substrate ends a and b and two washcoat zones A and B, wherein washcoat zone A comprises a redox active base metal and palladium supported on a zeolite and/or refractory oxide support and extends starting from substrate end a over a part of the length L, and washcoat zone B comprises the same components as washcoat A and an additional amount of palladium and extends from substrate end b over a part of the length L, wherein L=L.sub.A+L.sub.B, wherein L.sub.A is the length of washcoat zone A and L.sub.B is the length of substrate length B.

A catalyst article including a substrate with an inlet end and an outlet end, a first zone and a second zone, where the first zone comprises: a) an ammonia slip catalyst (ASC) bottom layer comprising a platinum group metal on a support; and b) an SCR layer comprising a second SCR catalyst, the SCR layer located over the ASC bottom layer; where the second zone comprises a catalyst (second zone catalyst) selected from the group consisting of a diesel oxidation catalyst (DOC) and a diesel exotherm catalyst (DEC); wherein the ASC bottom layer extends into the second zone; and where the first zone is located upstream of the second zone. The ASC bottom layer may include a blend of: (1) the platinum group metal on a support and (2) a first SCR catalyst.

A honeycomb structure includes a pillar-shaped honeycomb structure body having porous partition walls, wherein the partition walls have projecting portions, in the cells of 10% or more of the plurality of cells, the projecting portions project into the cells, a tip curvature radius R of an apex of each of the projecting portions is from 0.01 to 0.1 mm, side surfaces of the projecting portions are inclined to the surfaces of the partition walls at an inclination angle of 40 to 70, and a relation of 0.04H/A0.4 is satisfied.

Disclosed herein are catalyst compositions for removing formaldehyde, volatile organic compounds, and other pollutants from an air flow stream. In one embodiment, a catalyst composition comprises manganese oxide particles and rare earth metal catalyst particles.

An element frame assembly (1) comprising an element frame (2) for holding at least one monolith (3) containing catalysts in the flow of exhaust gases from a combustion source. The element frame (2) comprising two pairs of opposing walls (10), an interior (11) formed by the walls (10), an inlet end (12) and an outlet end (13). The least one monolith (3) comprising an inlet (20), an outlet (20), four sides (22) and at least one catalyst. At least one knit wire mesh bearing element (4) is provided such that there is at least a portion of the at least one knit wire mesh bearing element (4) between the at least one monolith (3) and each adjacent wall (10) of the element frame (2).

Provided is a method of producing a catalyst or adsorbent carrier and a catalyst or adsorbent carrier which can enhance a catalyst or adsorbent function, and prevent fall-off of catalyst particles or adsorbent particles. The surface of a metal base material made of aluminum or an aluminum alloy is subjected to an etching process using an etchant containing iron chloride and an oxide to convert the surface to an uneven and rough surface. The uneven and rough surface of the metal base material is subjected to an anodizing process to form a porous coating along the uneven and rough surface. A large number of catalyst or adsorbent particles are thus carried on the surface of the metal base material on which the porous coating is formed along the uneven and rough surface.

A ceramic honeycomb structure includes: an outer peripheral wall; and a partition wall disposed on an inner side of the outer peripheral wall, the partition wall defining a plurality of cells, each of the plurality of cells to form a fluid flow path extending from one end face to other end face. The honeycomb structure contains: 1) particles including one or more selected from silicon carbide, silicon nitride and aluminum nitride; and 2) silicon doped with a dopant. The dopant is a Group 13 element or a Group 15 element. The honeycomb structure has a silicon content (B) of from 20 to 80% by mass, and the honeycomb structure has a porosity of 30% or less.

Catalyzed particulate filters comprise three-way conversion (TWC) catalytic material, which comprises rhodium as the only platinum group metal, that permeates walls of a particulate filter. Such catalyzed particulate filters may be located downstream of close-coupled three-way conversion (TWC) composites in an emission treatment system downstream of a gasoline direct injection engine for treatment of an exhaust stream comprising hydrocarbons, carbon monoxide, nitrogen oxides, and particulates.

The present disclosure provides catalyst compositions and catalytic articles capable of storing and/or reducing nitrogen oxide (NO.sub.x) emissions in engine exhaust, catalyst articles coated with such compositions, and processes for preparing such catalyst compositions and articles. The catalyst compositions include copper and palladium co-exchanged zeolites. Further provided is a process for preparing such co-exchanged zeolites, an exhaust gas treatment system including the catalytic articles disclosed herein, and methods for reducing NO.sub.x in an exhaust gas stream using such catalytic articles and systems.

A novel catalyst constituent material for combustion gas purification, which has an extremely good ratio of contact between each catalyst metal particle and an exhaust gas; and a catalyst device which uses this catalyst constituent material for combustion gas purification; and a method for producing this catalyst constituent material for combustion gas purification. The catalyst constituent obtained by mixing catalyst metal particles and a pore-forming material that disappears at high temperatures into a catalyst supporting material, which is a slurry containing fine ceramic particle. The pore-forming material also contains long fibers of cellulose nanofibers and/or short fibers of cellulose nanofibers.