Abstract:
In an exhaust gas purification system provided with a denitration catalyst layer (1), a reducing agent oxidation catalyst layer (2) is installed together; a reducing agent and air are supplied into the reducing agent oxidation catalyst layer (2) at the time of catalyst regeneration of the denitration catalyst layer (1); a high-temperature oxidation reaction gas is produced by a reaction heat generated by an oxidation reaction of the reducing agent and the air in this reducing agent oxidation catalyst layer (2); and this high-temperature oxidation reaction gas is introduced into the denitration catalyst layer (1) to heat the denitration catalyst, thereby recovering a denitration performance of the catalyst.
Abstract:
The present disclosure describes hybrid binary catalysts (HBCs) that can be used as engine aftertreatment catalyst compositions. The HBCs provide solutions to the challenges facing emissions control. In general, the HBCs include a porous primary catalyst and a secondary catalyst. The secondary catalyst partial coats the surfaces (e.g., the internal porous surface and/or the external surface) of the primary catalyst resulting in a hybridized composition. The synthesis of the HBCs can provide a primary catalyst whose entire surface, or portions thereof, can be coated with the secondary catalyst.
Abstract:
The present disclosure describes hybrid binary catalysts (HBCs) that can be used as engine aftertreatment catalyst compositions, specifically 4-way catalyst compositions. The HBCs provide solutions to the challenges facing emissions control. In general, the HBCs include a porous primary catalyst and a secondary catalyst. The secondary catalyst partial coats the surfaces (e.g., the internal porous surface and/or the external surface) of the primary catalyst resulting in a hybridized composition. The synthesis of the HBCs can provide a primary catalyst whose entire surface, or portions thereof, can be coated with the secondary catalyst.
Abstract:
Catalytic cores for a wall-flow filter include juxtaposed channels extending longitudinally between an inlet side and an outlet side of the core, wherein the inlet channels are plugged at the outlet side and outlet channels are plugged at the inlet side. Longitudinal walls forming the inlet and outlet channels separate the inlet channels from the outlet channels. The walls include pores that create passages extending across a width of the walls from the inlet channels to the outlet channels. Catalysts are distributed across the width and length of the walls within internal surfaces of the pores in a manner such that the loading of each catalyst across the width varies by less than 50% from an average loading across the width.
Abstract:
An exhaust system for an internal combustion engine is disclosed. The exhaust system comprises a particulate filter, one or more NOx reduction catalysts, and a low pressure exhaust gas recirculation (EGR) circuit for connecting the exhaust system downstream of the filter and the one or more NOx reduction catalysts to an intake of the engine. The EGR circuit comprises a N2O-producing catalyst.
Abstract:
A method for removing nitrogen oxides NOx from a gaseous current, comprising the steps of: passing the gaseous current through a de-NOx catalytic bed with iron exchanged zeolite as a catalyst with the addition of ammonia as a reducing agent, wherein the molar ratio of NH3 over NOx is greater than 1.33.
Abstract:
An exhaust system (10) for a vehicular lean burn internal combustion engine (12), which system comprising a conduit (14) for carrying a flowing exhaust gas, a source of nitrogenous reductant (26), an alumino silicate small pore zeolite catalyst containing a maximum ring size of eight tetrahedral atoms having the CHA Framework Type Code and containing at least one transition metal which consists of copper and is coated on a monolith substrate disposed in a flow path of the exhaust gas and means (22, 28, 30) for metering the nitrogenous reductant from the source of nitrogenous reductant (26) into a flowing exhaust gas upstream of the aluminosilicate zeolite catalyst (20), wherein an oxidation catalyst (16) comprising at least one platinum group metal for oxidising nitrogen monoxide to nitrogen dioxide is located upstream of the means (22) for metering the nitrogenous reductant into a flowing exhaust gas.
Abstract:
A three-way catalyst is disclosed. The three-way catalyst comprises a palladium component comprising palladium and a ceria-zirconia-alumina mixed or composite oxide, and also comprises a rhodium component comprising rhodium and a zirconia-containing material. The palladium component and the rhodium component are coated onto a silver-containing extruded molecular sieve substrate. The invention also includes an exhaust system comprising the three-way catalyst. The three-way catalyst results in improved hydrocarbon storage and conversion, in particular during the cold start period.
Abstract:
A zeolite catalyst for converting nitrogen oxides in a gas to nitrogen by contacting the nitrogen oxides with a nitrogenous reducing agent in the presence of the zeolite catalyst, which zeolite catalyst comprising a small pore zeolite containing a maximum ring size of eight tetrahedral atoms and having the AEI Framework Type Code and containing a total of from 0.01 to 20 weight percent of at least one transition metal selected from the group consisting of Cr, Ce, Mn, Fe, Co, Ni and Cu, based on the total weight of the zeolite catalyst.
Abstract:
An oxidation catalyst composite, methods, and systems for the treatment of exhaust gas emissions from a diesel engine are described. More particularly, an oxidation catalyst composite including a first washcoat comprising a zeolite, Pt, and first refractory metal oxide support containing manganese, a second washcoat comprising a second refractory metal oxide support, a Pt component and a Pd component, and a third washcoat comprising palladium and a rare earth oxide component is described.