A method for controlling a reductant generation device 100, the reductant generation device 100 including: a sprayer 10 capable of spraying a reductant precursor 50; and a heater 20 comprising a ceramic substrate 21, the heater 20 being arranged on a downstream side of the sprayer 10 and capable of heating the reductant precursor 50 to generate a reductant 60. The method includes: a permeation step of spraying the reductant precursor 50 from the sprayer 10 and permeating the ceramic substrate 21 with the reductant precursor 50 when the heater is not heated; and after the permeation step, a heating step A of heating the reductant precursor 50 by the heater 20 and generating the reductant 60 while spraying the reductant precursor 50 from the sprayer 10.

A reductant delivery system includes an inlet body, an outlet body, and an outer transfer tube. The inlet body includes an inlet body coupler, an inlet body outer transfer shell, and an inlet body inner shell. The inlet body coupler surrounds an inlet body inlet that is configured to receive exhaust gas. The inlet body outer transfer shell is coupled to the inlet body coupler. The inlet body outer transfer shell includes an inlet body outer transfer shell inner surface and an inlet body outer transfer shell outlet. The inlet body outer transfer shell outlet extends through the inlet body outer transfer shell inner surface. The inlet body inner shell includes an inlet body inner shell first flange, an inlet body inner shell second flange, and an inlet body inner shell wall. The inlet body inner shell first flange is coupled to the inlet body outer transfer shell inner surface.

Systems and methods for controlling a gasoline urea selective catalytic reductant catalyst are described. In one example, an observer is provided that corrects an estimate of an amount of NH.sub.3 that is stored in a SCR. The amount of NH.sub.3 that is stored in the SCR is a basis for generating additional NH.sub.3 or ceasing generation of NH.sub.3.

A deterioration determination apparatus is usable with an ammonia sensor that includes an ammonia element portion that includes, a solid electrolyte, an ammonia electrode, and a reference electrode. The deterioration determining apparatus compares a first evaluation value and a second evaluation value, and determines whether deterioration has occurred in the ammonia element portion of the ammonia sensor at an evaluation time or subsequent to the evaluation time. The first evaluation value is based on a first sensor current obtained when a DC voltage is applied between the ammonia electrode and the reference electrode of the ammonia element portion at an initial time that is during an initial use period of the ammonia sensor. The second evaluation value is based on a second sensor current obtained when the DC voltage is applied between the ammonia electrode and the reference electrode subsequent to the initial period of use of the ammonia sensor.

An ammonia generating apparatus comprises a housing comprising a first end wall on which a reductant injector configured to insert a reductant into the housing is mountable. A heating coil assembly is disposed within the housing. A first end of the heating coil assembly is located proximate to a location of the first end wall where a reductant injector tip of the reductant injector is located when the reductant injector is mounted on the first end wall. The heating coil assembly is configured to generate heat sufficient to thermolyze the reductant to generate ammonia and reaction byproducts, in response to an electric current being passed therethrough. A hydrolysis catalyst can be disposed downstream of the heating coil assembly for catalyzing hydrolysis of the reaction byproducts into ammonia.

Described are exhaust gas treatment systems for treatment of a gasoline engine exhaust gas stream. The exhaust gas treatment systems comprise an ammonia generating catalyst and an ammonia selective catalytic reduction (SCR) catalyst downstream of the ammonia generating catalyst. The ammonia generating catalyst comprises a NO.sub.x storage component, a refractory metal oxide support, a platinum component, and a palladium component. The ammonia generating catalyst is substantially free of ceria. The platinum and palladium components are present in a platinum to palladium ratio of greater than about 1 to 1.

A method of recovering catalyst performance includes providing a vanadium selective catalytic reduction (VSCR) catalyst. The method includes exposing the VSCR catalyst to a first humidity level in a range of 50%-100% relative humidity, at a first temperature in a range of 20° C.-100° C., for a first period of time of at least two hours. The method includes thermally treating the VSCR catalyst at a second temperature in a range of 300° C.-600° C. for a second period of time of at least than one hour.

A method for controlling an exhaust gas aftertreatment system, wherein the system includes a first selective catalytic reduction (SCR) device, a catalytic particulate filter arrangement arranged downstream of the first SCR device, and a second selective catalytic reduction (SCR) device arranged downstream of the catalytic particulate filter arrangement. The method includes estimating future exhaust conditions based upon predicted vehicle operating conditions (s403); —estimating a future NOx conversion demand based on the estimated future exhaust conditions (s405); —dosing a reducing agent from a first reducing agent dosing device at a rate based at least on the estimated future NOx conversion demand (s406).

A urea solution injection device includes an exhaust pipe for discharging exhaust gas generated in a combustion chamber to the exterior; an injector is installed and pierces into the exhaust pipe to inject urea solution into the exhaust gas flowing in the exhaust pipe. A catalyst is disposed at a position after the injector when viewed in a flow direction of the exhaust gas and the exhaust gas is discharged to the exterior to decompose the exhaust gas mixed with the urea solution. A urea solution mixer is provided at an end of the injector and installed and pierces into the exhaust pipe. Accordingly the urea solution injected from the injector is dispersed therein. An installation unit provides for the urea solution mixer to be installed in the exhaust pipe and pierces into the exhaust pipe.

The present invention relates to a composition comprising a non-zeolitic oxidic material comprising alumina; an 8-membered ring pore zeolitic material comprising one or more of copper and iron, wherein the framework structure of the zeolitic material comprises a tetravalent element Y, a trivalent element X and oxygen, wherein the molar ratio of Y:X, calculated as YO.sub.2X.sub.2O.sub.3, is in the range of from 2: 1 to 40: 1; wherein at least part of the outer surface of the zeolitic material is covered by a layer comprising the non-zeolitic oxidic material; wherein Y comprises one or more of Si, Sn, Ti, Zr and Ge and X comprises one or more of Al, B, In and Ga.