The present invention relates to a method for diagnosing aftertreatment of exhaust gases resulting from combustion, wherein at least a first substance resulting from said combustion is reduced by supplying additive to an exhaust gas stream resulting from said combustion and use of a first reduction catalytic converter. The method includes: estimating an accumulated expected reduction of said first substance during a first period of time, determining an accumulated actual reduction of said first substance during a period of time at least substantially overlapping said first period of time, and generating a signal indicating a fault in said reduction of said first substance when said accumulated actual reduction differs from said accumulated expected reduction by a predetermined difference in occurrence of said first substance. The invention also relates to a corresponding system.

An exhaust gas purification catalyst showing resistance to peeling and high purification performance is provided. The present invention is an exhaust gas purification catalyst including a base material and a catalyst layer disposed on the base material. The catalyst layer includes a catalytic metal, a first metal oxide, and a second metal oxide having a higher heat resistance than that of the first metal oxide. When Dx is an area-based average particle diameter of the first metal oxide determined from an arbitrary cross section of the catalyst layer and Dy is an area-based particle diameter of the second metal oxide 22 measured from the cross section of the catalyst layer, a ratio of the Dy to the Dx (Dy/Dx) is 5 or more, and the Dy is 7 μm or more. In the catalyst layer, pore volume of pores having pore diameters 30 nm or more measured by a nitrogen adsorption method is 0.28 cm.sup.3/g or more.

An aftertreatment system for a diesel engine may include a diesel particulate filter configured for placement in fluid communication with the diesel engine to receive an exhaust flow. The system may also include a selective catalytic reduction system configured for arrangement downstream of the diesel particulate filter and a NO.sub.x sensor configured to measure a NO.sub.x concentration in the exhaust flow entering the selective catalytic reduction system. The system may also include a controller configured to estimate a ratio of NO.sub.2 to NO.sub.x downstream of the diesel particulate filter and based on a factor affecting the generation of NO.sub.2 upstream of the selective catalytic reduction system. The controller may also be configured to adjust the measured NO.sub.x concentration based on the ratio to provide an estimated actual NO.sub.x concentration and dose diesel exhaust fuel into the exhaust flow based on the estimated actual NO.sub.x concentration.

The present disclosure generally provides catalysts, catalytic articles and catalyst systems including such catalytic articles. In particular, the catalyst composition includes a zeolite having a chabazite (CHA) crystal structure ion-exchanged with iron and copper. Methods of making and using the catalyst composition are also provided, as well as emission treatment systems containing a catalyst article coated with the catalyst composition. The catalyst article present in such emission treatment systems is useful to catalyze the reduction of nitrogen oxides in gas exhaust in the presence of a reductant.

Metal oxide nanoarrays, such as titanium oxide nanoarrays, having a platinum group metal dispersed thereon and methods of making such nanoarrays are described. The platinum group metal can be dispersed on the metal oxide nanoarray as single atoms. The nanoarrays can be used to catalyze oxidation of combustion exhaust.

Catalysts, catalytic materials, catalytic forms, methods for preparation the same, methods for using the same in catalytic combustion processes, and methods and systems for conducting such combustion processes are provided.

A catalytic converter includes at least one heating element that is configured to disrupt the direction of flow of exhaust gases which contain harmful toxic gases and pollutants and aid in removing and/or reducing said toxic gases and pollutants.

System (2) for CO.sub.2 capture from a combustion engine (1) comprising an exhaust gas flow circuit (6) having an inlet end fluidly connected to an exhaust of the combustion engine, a heat exchanger circuit (12), a primary exhaust gas heat exchanger (H1) for transferring heat from exhaust gas to fluid in the heat exchanger circuit, at least one compressor (10) for compressing fluid in a section of the heat exchanger circuit, the compressor driven by thermal expansion of heat exchanger circuit fluid from the primary exhaust gas heat exchanger (H1), and a CO.sub.2 temperature swing adsorption (TSA) reactor (4) fluidly connected to an outlet end of the exhaust gas flow circuit. The TSA reactor includes at least an adsorption reactor unit (D4) and a desorption reactor unit (D2), the heat exchanger circuit comprising a heating section (12b) for heating the desorption unit (D2) and a cooling section (12a) for cooling the adsorption unit (D4).

A diesel engine emissions catalyst which may be used to fill a niche between standard oxidation catalyst and diesel particulate filters for control of diesel particulate matter. The catalyst includes a structure (substrate) comprising one or more coated, corrugated micro-expanded metal foil layers. The coated surface may be a high surface area, stabilized, and promoted washcoat layer. The corrugated pattern may include a herringbone-style pattern that, when in use, is oriented in a longitudinal direction of the diesel engine exhaust flow. The micro-expanded metal foil provides small openings or eyes that, as the exhaust flow passes through the catalyst (transverse to the eye opening), particulates in the flow impinge on the surface and becomes trapped in the eyes. The catalyst may be used to treat a locomotive engine exhaust stream and may be used with a selective catalyst reduction system.

A gas purification device includes: a converter packed with a catalyst for hydrolyzing both carbonyl sulfide and hydrogen cyanide; an upstream heat exchanger for heat exchange between a gas to be introduced into the converter and a cooling fluid for cooling the gas; a reaction-temperature estimation member for estimating a reaction temperature inside the converter; and a flow-rate adjustment member for adjusting a flow rate of the cooling fluid flowing into the upstream heat exchanger based on an estimated value of the reaction-temperature estimation member to control the reaction temperature.