An exhaust aftertreatment device includes a housing defining an inlet and an outlet. A plurality of first substrate layers are positioned within the housing in fluid receiving communication with the inlet. The plurality of first substrate layers define a first flow direction, and the plurality of first substrate layers comprise a passive NOx adsorber washcoat. A plurality of second substrate layers are positioned within the housing with the first and second substrate layers being layered in alternating order. The plurality of second substrate layers define a second flow direction perpendicular to the first flow direction, and the plurality of second substrate layers comprise a selective catalytic reduction washcoat. A connecting passage is in fluid receiving communication with the plurality of first substrate layers and in fluid providing communication with the plurality of second substrate layers.

A muffler is detachably attached to an engine. A catalyst for purifying exhaust gas is provided upstream of the muffler, and a secondary air valve for supplying air to an exhaust passage is provided upstream of the catalyst. The catalyst and the secondary air valve are integrally unitized. A catalyst unit including the catalyst and the secondary air valve is provided between the engine and the muffler.

The invention relates to a catalytic module including a solid support and a stack including at least the following layers arranged in the following order, taking the solid support as a base: a first porous layer containing CeO.sub.2 and deposited by chemical vapour deposition, and a first catalytic layer containing at least one metal and/or at least one alloy of metals.

The present invention relates to a catalyst comprising a carrier substrate of the length L extending between substrate ends a and b and a first washcoat zone, which comprises a) a zeolite, b) a redox active base metal compound and c) palladium in oxidic or metallic state which is fixed to the surface of a support oxide.

A process for the removal of nitrous oxide (N.sub.2O) contained in a process off-gas in an axial flow reactor. The process includes the steps of (a) adding an amount of reducing agent into the process off-gas; (b) in a first stage passing in axial flow direction the process off-gas admixed with the reducing agent through a first monolithic shaped catalyst active in decomposing nitrous oxide by reaction with the reducing agent to provide a gas with a reduced amount of nitrous oxide and residual amounts of reducing agent; and (c) in a second stage passing the gas with a reduced amount of nitrous oxide and residual amounts of the reducing agent in axial flow direction through a second monolithic shaped catalyst active in oxidation of the residual amounts of the reducing agent.

An exhaust system for a diesel engine comprises an oxidation catalyst for treating an exhaust gas from the diesel engine and an emissions control device, wherein the oxidation catalyst comprises: a first washcoat zone for oxidizing carbon monoxide (CO) and hydrocarbons (HCs), wherein the first washcoat zone comprises a first platinum group metal (PGM), which is a combination of platinum and palladium, a first support material and a hydrocarbon adsorbent material, which is a zeolite, and wherein the first washcoat zone does not comprise rhodium and is substantially free of manganese or an oxide thereof; a second washcoat zone for oxidizing nitric oxide (NO), wherein the second washcoat zone comprises platinum (Pt) and manganese (Mn) disposed or supported on a second support material, wherein the second support material comprises a refractory metal oxide, wherein the refractory metal oxide is silica-alumina or an alumina doped with silica in a total amount of 0.5 to 45% by weight of the alumina, and wherein the second washcoat zone does not comprise a hydrocarbon adsorbent material, which is a zeolite; and a substrate having and inlet end and an outlet end, and wherein the second washcoat zone is disposed at an outlet end of the substrate, and the first washcoat zone disposed at an inlet end of the substrate; and wherein the emissions control device is a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction filter catalyst, a diesel particulate filter (DPF), or a catalyzed soot filter (CSF).

A selective catalytic reduction system applying diesel oil as reductant for converting nitrogen oxides by means of a catalyst into diatomic nitrogen and water in a diesel engine is provided. The selective catalytic reduction system includes an oil injection system, a reactor and a number of selective catalytic reduction catalysts provided in a first section. The selective catalytic reduction system includes at least one additional section including a number of selective catalytic reduction catalysts. The at least one additional section is provided in a non-zero from the first section.

The invention provides an exhaust gas cleaning oxidation catalyst and in particular to an oxidation catalyst for cleaning the exhaust gas discharged from internal combustion engines of compression ignition type (particularly diesel engines). The invention further relates to a catalysed substrate monolith comprising an oxidising catalyst on a substrate monolith for use in treating exhaust gas emitted from a lean-burn internal combustion engine. In particular, the invention relates to a catalysed substrate monolith comprising a first washcoat coating and a second washcoat coating, wherein the second washcoat coating is disposed in a layer above the first washcoat coating.

Provided are a mercury oxidation catalyst support structure with which a mercury oxidation reaction can be carried out while inhibiting the oxidation reaction for SO.sub.2 included in exhaust gas and a method for manufacturing the same. This mercury oxidation catalyst structure is characterized by vanadium being unevenly supported on the surface of the support structure. The method for manufacturing the mercury oxidation catalyst structure includes a step of incorporating an inactive support throughout from the inside to the surface of the structure using an inactive support-containing liquid and a step of immersing the structure having been subjected to the step in a liquid containing vanadium or applying the same liquid to the surface of the same structure, followed by drying and calcinating, thereby supporting vanadium on the inactive support present in the surface of the structure.

The invention relates to a catalytic converter for treating exhaust gases of an internal combustion engine, having a housing through which an exhaust gas may flow and which has an inflow side and an outflow side, wherein, in the housing, there is formed a plurality of flow channels (4, 13) which is flowed through along a main throughflow direction from the inflow side to the outflow side, wherein, in the housing, there is arranged at least one pipeline (5, 12) which is flowed through by a fluid which is independent of the exhaust gas that is caused to flow through the flow channels (4, 13).