A catalyst deterioration diagnosis method is a method for a system. The system includes a stepped transmission or a continuously variable transmission connected to an internal combustion engine, a catalyst into which an exhaust gas from the internal combustion engine is introduced, and a gas sensor having sensitivity to ammonia that outputs a detection value corresponding to a component of an exhaust gas that has passed through the catalyst. The catalyst deterioration diagnosis method includes the following steps. Monitoring of temporary increase of a detection value of the gas sensor is started, and thereby a temporarily increased amount of the detection value of the gas sensor is acquired. The monitoring is started when upshifting of the stepped transmission or pseudo-upshifting of the continuously variable transmission is performed. Whether or not the temporarily increased amount is larger than a threshold amount is determined.

An energy recovery converter for exhaust gases or waste heat is provided. The converter includes a membrane electrode assembly (MEA), an exhaust gas having a first molecular oxygen content, and an external electrical load. The MEA includes a first electrode, a second electrode and an oxygen ion conductive membrane sandwiched between the first and second electrodes. Each of the first and second electrodes includes at least one oxidation catalyst configured to promote an electrochemical reaction. The second electrode of the MEA is exposed to the exhaust gas and the first electrode of the MEA is exposed to a gas having a second molecular oxygen content. The second molecular oxygen content is higher than the first molecular oxygen content. The external electrical load is connected between the first and second electrodes of the MEA.

A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate comprising an inlet end and an outlet end with an axial length L; a first catalytic region comprising a first platinum group metal (PGM) component, wherein the first PGM component comprises Rh and Pt; a second catalytic region comprising a second PGM component, wherein the second PGM component comprises Pd; and wherein the first PGM component has a Pt to Rh ratio of at least 1:20.

An gas purification catalyst device having a catalyst coated layer formed on at least one base material, wherein: the catalyst coated layer includes a first catalyst coated layer on the upstream side of an exhaust gas flow, and a second catalyst coated layer on the downstream side of the exhaust gas flow; the first catalyst coated layer includes a hydrocarbon adsorbent and a catalytic precious metal; and the second catalyst coated layer includes a nitrogen oxide adsorbent and a catalytic precious metal.

A honeycomb filter includes a pillar-shaped honeycomb structure body having a porous partition wall disposed to surround a plurality of cells and a plugging portion, wherein the partition wall is composed of a material containing cordierite as a main component thereof, porosity of the partition wall measured by a mercury press-in method is 60 to 68%, an average pore diameter of the partition wall measured by a mercury press-in method is 8 to 12 and in a pore diameter distribution which indicates a cumulative pore volume of the partition wall measured by a mercury press-in method, with a pore diameter (μm) on an abscissa axis and a log differential pore volume (cm.sup.3/g) on an ordinate axis, a first peak that includes a maximum value of the log differential pore volume has a pore diameter value of 10 μm or less, the pore diameter value corresponding to a ⅓ value width of the maximum value.

A thin-walled honeycomb body (100) having a plurality of repeating cell structures (110) formed of intersecting porous thick walls (112V, 112H) and thin walls (114V, 114H). Each repeating cell structure (110) is bounded on its periphery by the thick walls (112V, 122H) of a first transverse thickness (Tk) and the thin walls (114V, 114H) have a second transverse thickness (Tt) that subdivides each repeating cell structure (110) into between 7 and 36 individual cells (108). In the thin-walled honeycomb body (100), the first transverse thickness (Tk) of the thick walls (112V, 112H) is less than or equal to 0.127 mm (0.005 inch) and the second transverse thickness (Tt) of the thin walls (114V, 114H) is less than or equal to 0.0635 mm (0.0025 inch), and Tk>Tt. Honeycomb extrusion dies and methods of manufacturing the thin-walled honeycomb body (100) having thick walls (112V, 112H) and thin walls (114V, 114H) are provided.

Catalyzed particulate filters comprise three-way conversion (TWC) catalytic material that permeates walls of a particulate filter such that the catalyzed particulate filter has a coated porosity that is less than an uncoated porosity of the particulate filter. The coated porosity is linearly proportional to a washcoat loading of the TWC catalytic material. A coated backpressure is non-detrimental to performance of the engine. Such catalyzed particulate filters may be used 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.

A ceramic honeycomb body, suitable for use in exhaust gas processing, includes a honeycomb structure having a plurality of through-channels, a first portion of the plurality of through-channels have a first hydraulic diameter dh1, a second portion of the plurality of through-channels have a second hydraulic diameter that is smaller than the first hydraulic diameter dh1, the first hydraulic diameter dh1 is equal to or greater than 1.1 mm, and the first and second portions of through-channels, taken together, have a geometric surface area GSA greater than 2.9 mm.sup.−1. Diesel oxidation catalysts and methods of soot removal are also provided, as are other aspects.

The invention relates to an exhaust gas aftertreatment system for a spark ignition internal combustion engine based on the Otto principle. The internal combustion engine is connected on the outlet side to an exhaust gas system, wherein an electrically heatable three-way catalytic converter, a four-way catalytic converter downstream from the electrically heatable three-way catalytic converter, and a further three-way catalytic converter downstream from the four-way catalytic converter are situated in the exhaust gas system in the flow direction of an exhaust gas through the exhaust gas system. Before the internal combustion engine is started, the electrically heatable three-way catalytic converter and preferably also the four-way catalytic converter are heated to allow efficient exhaust gas aftertreatment of the untreated emissions of the internal combustion engine upon starting the internal combustion engine. The exhaust gas aftertreatment system is also configured to allow efficient conversion of the pollutants also during a regeneration of the four-way catalytic converter, and thus, to ensure particularly low emissions in all operating states of the motor vehicle.

An oxidation catalyst for treating an exhaust gas from a diesel engine comprises: a first washcoat region for oxidising carbon monoxide (CO) and hydrocarbons (HCs), wherein the first washcoat region comprises a first platinum group metal (PGM) and a first support material, and wherein the first washcoat region does not comprise manganese or an oxide thereof; a second washcoat region for oxidising nitric oxide (NO), wherein the second washcoat region comprises platinum (Pt), manganese (Mn) and a second support material comprising a refractory metal oxide, which is silica-alumina or alumina doped with silica in a total amount of 0.5 to 45% by weight of the alumina, wherein the platinum (Pt) is disposed or supported on the second support material and the manganese (Mn) is disposed or supported on the second support material; and a substrate having an inlet end and an outlet end, and wherein the first washcoat region is a first washcoat layer and the second washcoat region is a second washcoat layer, and the second washcoat layer is disposed on the first washcoat layer; and wherein when the oxidation catalyst comprises a hydrocarbon adsorbent, which is a zeolite, then the first washcoat region further comprises the hydrocarbon adsorbent.