An ammonia oxidation catalyst device, including a substrate, a first catalyst coat layer and a second catalyst coat layer, wherein: the first catalyst coat layer includes inorganic oxide particles and a catalytic noble metal supported on the inorganic oxide particles; the second catalyst coat layer includes an NO.sub.x selective reduction catalyst and a proton zeolite H-Zeolite; the first catalyst coat layer is present on the substrate; and the second catalyst coat layer is present on the first catalyst coat layer.

An apparatus and method for treating a semiconductor process gas comprises a gas inlet allowing a treatment target gas (or gas to be treated) to flow therethrough; a catalytic reaction portion including a catalyst and configured to allow the treatment target gas to be brought into contact with the catalyst; a space velocity controller between the gas inlet and the catalytic reaction portion, the space velocity controller extending from the gas inlet in a diagonal direction in relation to the gas inlet; a differential pressure buffer portion between the space velocity controller and the catalytic reaction portion and including a filter; and a gas outlet configured to externally discharge a product formed as the treatment target gas comes into contact with the catalyst.

CHA-type zeolite in which the molar ratio of silica to alumina is less than 13, and the content of sodium is 100 ppm or more and 2000 ppm or less is provided. Such a CHA-type zeolite is obtained by a manufacturing method including obtaining a crystallized product by crystallizing a composition which includes a structure-directing agent source containing at least N,N,N-trialkylcyclohexylammonium cation, an alumina source, a silica source, a sodium source, and water and in which the molar ratio of silica to alumina is 20 or less and in which the molar ratio of potassium to sodium is less than 0.05, removing N,N,N-trialkylcyclohexylammonium cation from the crystallized product, and contacting the crystallized product with an ammonium-salt-containing solution having an ammonium concentration of 1 mass percent or more.

A NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst comprises a first layer consisting essentially of a support material, one or more platinum group metals disposed on the support material, and a NO.sub.x storage material.

A porous material includes an aggregate, and a binding material that binds the aggregate together in a state where pores are formed. The porous material contains 0.1 to 10.0 mass % of an MgO component, 0.5 to 25.0 mass % of an Al.sub.2O.sub.3 component, and 5.0 to 45.0 mass % of an SiO.sub.2 component with respect to the mass of the whole porous material, and further contains 0.01 to 5.5 mass % of an Sr component in terms of SrO.

A particulate filter includes a base material having a wall-flow structure including porous partition walls partitioning inlet and outlet cells, and wash-coating layers held inside partition walls. The wash-coating layers include inlet layers each formed from vicinity of an end portion at exhaust gas inflow side to have predetermined length and thickness and outlet layers each formed from vicinity of end portion at exhaust gas outflow side to have a predetermined length and thickness. The inlet and the outlet layers partially overlap with each other. Inlet layers of particulate filter contain substantially no noble metal catalyst, and outlet layers contain noble metal catalyst. Accordingly, PM collection performance can be easily enhanced in inlet region, and high gas distributability (pressure loss suppression performance) can be maintained in outlet region. Accordingly, it is possible to provide particulate filter capable of achieving high levels of PM collection performance and pressure loss suppression performance.

A catalyst material for abatement of exhaust gas emissions from a lean burn engine is provided, the catalyst material including a metal-exchanged SAPO-34 material, and an oxide layer at least partially covering an outside surface of the SAPO-34 material, wherein the oxide layer is not substantially blocking the pores of the SAPO-34 material.

A method of controlling an exhaust system for a diesel engine comprises providing an aftertreatment system comprising a first catalyst and a diesel exhaust fluid injection system, determining a preliminary dose of a diesel exhaust fluid of the diesel exhaust fluid injection system based on an incoming exhaust gas flow and an exhaust gas temperature, determining an NH.sub.3 factor based on incoming exhaust gas oxygen concentration and the incoming exhaust gas flow temperature, and determining a final dose of diesel exhaust fluid by multiplying the preliminary dose of diesel exhaust fluid by the NH.sub.3 factor.

A mixer apparatus for an exhaust gas aftertreatment system of a motor vehicle. The apparatus includes a housing having enveloping, first end, and second end walls. An injection opening for an exhaust gas aftertreatment agent is in the enveloping wall. An inlet opening is in the first end wall. The injection opening is configured for mounting a metering module. A rectilinear metering axis, which extends through the metering module and corresponds to an injection direction of exhaust gas aftertreatment agent injected into the housing, tangentially contacts, at a contact point, a theoretical cylinder, disposed in the housing, having a variable radius and a cylinder axis that is congruent with a central axis of the housing. A region of the metering axis extending from the injection opening to the contact point is located, with respect to inflowing exhaust gas, in the shelter of an opening-free region of the first end wall.

Provided is a catalyst having better denitration efficiency at low temperatures compared to the prior art, during a selective catalytic reduction reaction in which ammonia is used as a reducing agent. This denitration catalyst contains vanadium oxide including vanadium pentoxide and has a defect site in which oxygen deficiency occurs in a crystal structure of the vanadium pentoxide.