Abstract: An oxidation catalyst may include hydrocarbon storage material. One implementation relates to a diesel oxidation catalyst that includes a catalyst having a front zone and a rear zone and a gradient of hydrocarbon storage material on the catalyst extending from the front zone to the rear zone. The gradient of hydrocarbon storage material, may comprise a linear gradient, a step gradient, a parabolic gradient, a logarithmic gradient, or other forms thereof.

Abstract: An aftertreatment system comprises a SCR system including a catalyst formulated to decompose constituents of an exhaust gas passing therethrough. A filter is positioned upstream of the SCR system. The filter comprises a sulfur suppressing compound formulated to reduce an amount of SOx gases included in the exhaust gas flowing through the aftertreatment system. In particular embodiments, the filter comprises a filter housing and a filter element positioned within the filter housing. The filter element comprises the sulfur suppressing compound.

Abstract: Catalyst diagnostic limit parts and methods for making catalyst diagnostic limit parts are disclosed. An exemplary catalyst diagnostic limit part includes a substrate and a washcoat coating the substrate. The washcoat includes an active catalyst and an inactive catalyst at a predetermined ratio of active catalyst to inactive catalyst so as to control the performance of the catalyst diagnostic limit part.

Abstract: Catalyst diagnostic limit parts and methods for making catalyst diagnostic limit parts are disclosed. An exemplary catalyst diagnostic limit part includes a substrate and a washcoat coating the substrate. The washcoat includes an active catalyst and an inactive catalyst at a predetermined ratio of active catalyst to inactive catalyst so as to control the performance of the catalyst diagnostic limit part.

Abstract: A timing-based method for regenerating a DOC included in an aftertreatment system fluidly coupled to a dual-fuel engine comprises performing at least one of the following: a temperature of the DOC is varied while flowing a mixed exhaust gas, which comprises a mixture of a diesel-only exhaust gas and a natural gas exhaust gas, generated by the dual-fuel engine through the DOC; alternately the method includes flowing (a) the mixed exhaust gas generated by the dual-fuel engine and (b) a diesel-only exhaust gas generated by the dual-fuel engine through the DOC.

Abstract: A process for recovering performance of a component of an aftertreatment system. The component includes an inlet and an outlet. The inlet is positioned upstream relative to an exhaust gas flow through the aftertreatment system, and the outlet is positioned downstream relative to the exhaust gas flow through the aftertreatment system. The process includes removing the component from the aftertreatment system. The process also includes regenerating the component, such as subjecting the component to an acid wash and/or heat treating the component. The process further includes reinstalling the component into the aftertreatment system with the inlet positioned downstream relative to the exhaust gas flow through the aftertreatment system and the outlet positioned upstream relative to the exhaust gas flow through the aftertreatment system.

Abstract: Catalyst diagnostic limit parts and methods for making catalyst diagnostic limit parts are disclosed. An exemplary catalyst diagnostic limit part includes a substrate and a washcoat coating the substrate. The washcoat includes an active catalyst and an inactive catalyst at a predetermined ratio of active catalyst to inactive catalyst so as to control the performance of the catalyst diagnostic limit part.

Abstract: Described herein is a selective catalytic reduction (SCR) filter that includes a substrate that includes a first surface on a first side of the substrate and second surface on a second side of the substrate. The SCR filter further includes a semi-permeable membrane applied to the first surface. Additionally, the SCR filter includes an SCR washcoat applied to the second surface.

Abstract: A means for increasing the robustness of a SCR after-treatment system is provided. Specifically, a hydrolysis catalyst coating is applied to multiple surfaces within a decomposition reactor to aid in urea and urea based deposit decomposition and mitigation of urea based deposits. The reactor includes an injector mount attached to a middle tube portion, an inlet tube, an outlet tube and a mixer. A hydrolysis catalyst coating is applied to an inner surface of the injector mount, an inner surface of the middle tube portion, an inner surface of the outlet tube and an outer edge of the mixer. The hydrolysis catalyst coating is capable of decomposing urea and urea based deposits that comes in contact with the hydrolysis catalyst coating and mitigates the formation of urea based deposits.

Abstract: Described are apparatuses, systems, and methods for treating exhaust. The described apparatus and systems typically include a catalytic device for converting aqueous urea to ammonia. The catalytic device may include a pyrolysis catalyst and a hydrolysis catalyst for converting aqueous urea to ammonia. The catalytic device typically includes an upstream face that is positioned at an angle relative to exhaust flow when the device is positioned in a selective catalytic reduction (SCR) system.

Abstract: A means for increasing the robustness of a SCR after-treatment system is provided. Specifically, a hydrolysis catalyst coating is applied to multiple surfaces within a decomposition reactor to aid in urea and urea based deposit decomposition and mitigation of urea based deposits. The reactor includes an injector mount attached to a middle tube portion, an inlet tube, an outlet tube and a mixer. A hydrolysis catalyst coating is applied to an inner surface of the injector mount, an inner surface of the middle tube portion, an inner surface of the outlet tube and an outer edge of the mixer. The hydrolysis catalyst coating is capable of decomposing urea and urea based deposits that comes in contact with the hydrolysis catalyst coating and mitigates the formation of urea based deposits.

Abstract: Disclosed are apparatuses, systems, and methods for treating exhaust. The disclosed apparatus and systems typically include a catalytic device for converting aqueous urea to ammonia. The catalytic device may include a pyrolysis catalyst and a hydrolysis catalyst for converting aqueous urea to ammonia. The catalytic device typically includes an upstream face that is positioned at an angle relative to exhaust flow when the device is positioned in a selective catalytic reduction (SCR) system.