Aftertreatment system

Abstract

An aftertreatment system includes a dispensing module. The aftertreatment system includes a selective catalytic reduction unit fluidly disposed downstream of the dosing module. The aftertreatment system includes a conduit fluidly connecting the dosing module to the selective catalytic reduction unit. The conduit has a coating disposed on a surface thereof. The coating is exposed to the discharge through the conduit and the selective catalytic reduction unit. The coating is configured to capture and inactivate platinum passing through the catheter.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This PCT patent application claims priority to U.S. Provisional Application No. 63 / 347,162, filed on May 31, 2022, which generally relates to the field of aftertreatment systems for use with internal combustion engine systems, and which is incorporated herein by reference in its entirety. Technical Field

[0002] The present application relates generally to the field of aftertreatment systems for use with internal combustion engine systems. background

[0003] For internal combustion engines such as diesel engines, nitrogen oxides (NO x ) compounds, which are typically treated with an aftertreatment system (e.g., an exhaust aftertreatment system). In order to reduce NO x emissions, a selective catalytic reduction (SCR) process can be implemented to convert NO x Compounds are converted to more neutral compounds, such as diatomic nitrogen, water, or carbon dioxide. Treatment typically includes treating (e.g., dosing, etc.) the exhaust with a reducing agent. The catalyst may be included in a catalyst chamber of an exhaust system, such as an exhaust system of a vehicle or power generation unit. A liquid reducing agent, such as anhydrous ammonia, aqueous ammonia, diesel exhaust fluid (DEF), or aqueous urea, is typically introduced into the exhaust stream prior to being introduced into the catalyst chamber. Overview

[0004] Embodiments described herein generally relate to systems and methods for capturing and deactivating platinum emissions in an aftertreatment system.

[0005] At least one aspect of the present disclosure relates to an aftertreatment system. The aftertreatment system includes a dosing module. The aftertreatment system includes a selective catalytic reduction (SCR) unit fluidly disposed downstream of the dosing module. The aftertreatment system includes a conduit fluidly connecting the dosing module to the SCR unit. The conduit has a coating disposed on a surface thereof. The coating is exposed to exhaust passing through the conduit and the SCR unit. The coating is configured to capture platinum passing through the conduit and deactivate the platinum.

[0006] In some embodiments, the aftertreatment system includes a decomposition chamber fluidly disposed upstream of the SCR unit. At least a portion of the inner surface of the decomposition chamber has a coating disposed thereon. In some embodiments, the aftertreatment system includes a mixer fluidly disposed upstream of the SCR unit and fluidly disposed downstream of the dosing module. At least a portion of the mixer has a coating disposed thereon. In some embodiments, at least a portion of the inlet of the SCR unit has a coating disposed thereon. In some embodiments, the coating includes at least one of copper, phosphorus, sodium, or silicon dioxide. In some embodiments, the aftertreatment system includes a platinum-containing diesel oxidation catalyst (DOC), and the coating is disposed on a surface downstream of the DOC. In some embodiments, the DOC is fluidly disposed upstream of the SCR unit. In some embodiments, the aftertreatment system includes a diesel particulate filter (DPF). The coating is disposed on the DPF. In some embodiments, the DPF is disposed between the DOC and the SCR unit.

[0007] Another aspect of the present disclosure relates to an aftertreatment system. The aftertreatment system includes a diesel oxidation catalyst (DOC). The DOC contains platinum. The aftertreatment system includes a conduit fluidly coupled to the DOC. The conduit has a coating disposed on a surface thereof. The coating is exposed to exhaust passing through the conduit and an SCR unit. The coating is configured to capture platinum passing through the conduit and deactivate the platinum.

[0008] In some embodiments, the conduit includes a decomposition chamber disposed therein. At least a portion of an inner surface of the decomposition chamber has a coating disposed thereon. In some embodiments, the post-treatment system includes a dosing module coupled to the decomposition chamber. The coating is disposed downstream of the dosing module. In some embodiments, the post-treatment system includes a mixer fluidly coupled to the conduit. At least a portion of the mixer has a coating disposed thereon. In some embodiments, the post-treatment system includes a selective catalytic reduction (SCR) unit fluidly coupled to the conduit. An inlet of the SCR unit has a coating disposed thereon. In some embodiments, the coating is disposed on a surface of the conduit downstream of the DOC.

[0009] Another aspect of the present disclosure relates to a system. The system includes an engine. The system includes an aftertreatment system in exhaust receiving communication with the engine. The aftertreatment system includes a dosing module. The aftertreatment system includes a selective catalytic reduction (SCR) unit fluidly disposed downstream of the dosing module. The aftertreatment system includes a conduit fluidly connecting the dosing module to the SCR unit. The conduit includes a coating disposed on a surface thereof. The coating is exposed to exhaust passing through the conduit and the SCR unit. The coating is configured to capture platinum passing through the conduit and deactivate the platinum.

[0010] In some embodiments, the system includes a decomposition chamber fluidly disposed upstream of the SCR unit. At least a portion of an inner surface of the decomposition chamber has a coating disposed thereon. A dosing module is coupled to the decomposition chamber. In some embodiments, the coating is unevenly disposed on the surface of the conduit such that the thickness of the coating near the dosing module is different from the thickness of the coating near the SCR unit. In some embodiments, the coating is uniformly disposed on the surface of the conduit. In some embodiments, the system includes a platinum-containing diesel oxidation catalyst (DOC). The DOC is fluidly disposed upstream of the dosing module. The conduit fluidly connects the DOC to the SCR unit. The coating is unevenly disposed on the surface of the conduit such that the thickness of the coating near the DOC is different from the thickness of the coating near the SCR unit.

[0011] Another aspect of the present disclosure relates to a method for treating an aftertreatment system. The method includes: determining, by a controller, that a selective catalytic reduction (SCR) unit of the aftertreatment system is downstream of one or more platinum-containing catalysts. The method also includes determining whether a diesel particulate filter is between one or more platinum-containing catalysts and the SCR unit. The method also includes selectively applying airflow treatment and heat treatment to one or more platinum-containing catalysts in response to determining that the diesel particulate filter is not between one or more platinum-containing catalysts and the SCR unit. The method also includes selectively applying heat treatment to one or more platinum-containing catalysts in response to determining that the diesel particulate filter is between one or more platinum-containing catalysts and the SCR unit.

[0012] In some embodiments, the method includes: in response to determining that a diesel particulate filter is not between one or more platinum-containing catalysts and the SCR unit, determining by a controller whether an iron SCR is a first SCR element of the SCR unit; in response to determining that the iron SCR is not the first SCR element, applying airflow treatment and mild thermal treatment to one or more platinum-containing catalysts by the controller; and in response to determining that the iron SCR is the first SCR element, applying airflow treatment and strong thermal treatment to one or more platinum-containing catalysts by the controller.

[0013] In some embodiments, the method includes determining, by a controller, whether an iron SCR is a first SCR element of an SCR unit in response to determining that a diesel particulate filter is between one or more platinum-containing catalysts and an SCR unit; applying, by the controller, a weak heat treatment to one or more platinum-containing catalysts in response to determining that the iron SCR is not the first SCR element; and applying, by the controller, a strong heat treatment to one or more platinum-containing catalysts in response to determining that the iron SCR is the first SCR element.

[0014] Those skilled in the art will appreciate that this summary is illustrative only and is not intended to be limiting in any way. Other aspects, inventive features and advantages of the devices and / or processes described herein, as limited only by the claims, will become apparent in the detailed description set forth herein and in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The details of one or more embodiments are described in the accompanying drawings and the following description. Other features, aspects and advantages of the present disclosure will become apparent from the specification, drawings and claims, in which:

[0016] Figure 1 A block diagram of an example aftertreatment system having an example reductant delivery system for an exhaust system is shown according to an embodiment.

[0017] Figure 2 A block diagram of an example system for capturing and deactivating platinum emissions is shown.

[0018] Figure 3 A graph showing the relationship between the platinum contained in the catalyst and the vehicle mileage according to an embodiment is shown.

[0019] Figure 4 The NO for an iron-based SCR unit according to an embodiment is shown. x Plots of conversion versus temperature and nitrous oxide (N2O) emissions versus temperature.

[0020] Figure 5 An untreated catalyst is shown.

[0021] Figure 6 A treated catalyst according to one embodiment is shown.

[0022] Figure 7 A flow chart for applying a heat treatment and / or an air flow treatment according to an embodiment is shown.

[0023] It will be appreciated that some or all of the drawings are schematic illustrations for illustrative purposes. The drawings are provided for the purpose of illustrating one or more embodiments, with the explicit understanding that they will not be used to limit the scope or meaning of the claims. Detailed Description

[0024] The following is a more detailed description of various concepts related to methods, devices, and systems for capturing and deactivating platinum emissions and implementations of these methods, devices, and systems. The various concepts introduced above and discussed in more detail below can be implemented in any of a number of ways, as the concepts described are not limited to any particular implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.

[0025] I. Overview Embodiments described herein relate to an aftertreatment system including a dosing module. The aftertreatment system includes a selective catalytic reduction (SCR) unit fluidly disposed downstream of the dosing module. The aftertreatment system includes a conduit fluidly connecting the dosing module to the SCR unit. The conduit has a coating disposed on a surface thereof. The coating is exposed to exhaust passing through the conduit and the SCR unit. The coating is configured to capture platinum passing through the conduit and deactivate the platinum. A system may include an engine and an aftertreatment system in communication with an engine exhaust receiver.

[0026] The aftertreatment system described herein can prevent platinum migration to the SCR catalyst. Preventing platinum migration to the SCR catalyst can extend the life of the SCR catalyst. Iron-based SCR catalysts may be particularly sensitive to platinum exposure. Platinum exposure can cause NO x Conversion is reduced and N2O emissions are increased, both of which are undesirable.

[0027] Other embodiments described herein relate to an aftertreatment system including a diesel oxidation catalyst (DOC) containing platinum. A conduit is fluidly coupled to the DOC. The conduit has a coating disposed on a surface thereof. The coating is exposed to exhaust passing through the conduit and an SCR unit. The coating is also configured to capture platinum passing through the conduit and deactivate the platinum.

[0028] II. Overview of the Aftertreatment System Figure 1 An aftertreatment system 100 is depicted for use with an engine. An engine, such as an internal combustion engine (e.g., a diesel internal combustion engine, etc.), generates exhaust gas. The aftertreatment system 100 has an example reductant delivery system 110 for an exhaust system 190. The exhaust system 190 receives exhaust gas from an internal combustion engine (e.g., a diesel internal combustion engine, etc.). In this manner, the aftertreatment system 100 is in exhaust gas receiving communication with the engine. The aftertreatment system 100 includes a dosing module 112, a selective catalytic reduction (SCR) unit 106 fluidly disposed downstream of the dosing module 112, and a conduit 210 fluidly connecting the dosing module 112 to the SCR unit 106. In one example, the aftertreatment system 100 includes a particulate filter (e.g., a diesel particulate filter (DPF) 102), a reductant delivery system 110, a decomposition chamber 104 (e.g., a reactor, etc.), and a selective catalytic reduction unit 106 (e.g., a catalyst chamber). The selective catalytic reduction (SCR) unit 106 may include a catalyst (e.g., an SCR catalyst). Aftertreatment system 100 may also include a sensor 150 .

[0029] The DPF 102 is configured to remove particulate matter, such as soot, from the exhaust gas flowing in the exhaust system 190. The DPF 102 includes an inlet at which the exhaust gas is received (e.g., from an engine manifold, etc.), and an outlet at which the exhaust gas exits after substantially filtering the particulate matter from the exhaust gas and / or converting the particulate matter into carbon dioxide. In some embodiments, the DPF 102 may be omitted.

[0030] The decomposition chamber 104 (e.g., a decomposition conduit) is configured to convert a reductant (such as urea or DEF) into ammonia. In some embodiments, the decomposition chamber 104 includes a reductant delivery system 110 having a dosing module 112 (e.g., a doser, etc.) configured to dosing the reductant into the decomposition chamber 104. In some embodiments, the reductant is injected upstream of the SCR unit 106 (e.g., a catalyst unit). The reductant droplets then undergo a process of evaporation, pyrolysis, and hydrolysis to form gaseous ammonia within the exhaust system 190. The decomposition chamber 104 includes an inlet and an outlet, the inlet being in fluid communication with the DPF 102 to receive a stream containing NO x Exhaust of emissions, the outlet is used to make exhaust, NO x Exhaust, ammonia, and / or reductant flow to the SCR unit 106 .

[0031] The decomposition chamber 104 includes a dosing module 112 mounted to the decomposition chamber 104 such that the dosing module 112 is positioned to dosing reductant into exhaust gas flowing in the exhaust system 190. The dosing module 112 includes a spacer 114 disposed between a portion of the dosing module 112 and a portion of the decomposition chamber 104 to which the dosing module 112 is mounted. The dosing module 112 is fluidly coupled to one or more reductant sources 116 (e.g., tanks, containers, etc.). In some embodiments, a reductant pressurizing pump 118 is used to pressurize the reductant from the reductant source 116 for delivery to the dosing module 112.

[0032] The dosing module 112 is also fluidly coupled to one or more air sources 115. For example, the air source 115 is or includes an air intake or air storage device (e.g., a tank, etc.). An air pump 117 (e.g., a lift pump, etc.) is used to pressurize the air from the air source 115 for delivery to the dosing module 112 (e.g., via a pressurized conduit, etc.). The dosing module 112 mixes the air from the air source 115 and the reductant from the reductant source 116 and provides the air-reductant mixture to the decomposition chamber 104.

[0033] The dosing module 112, the air pump 117, and the reductant pressurizing pump 118 are also electrically or communicatively coupled to the controller 120. The controller 120 is configured to control the dosing module 112 to dosing the air-reductant mixture into the decomposition chamber 104. The controller 120 is also configured to control the air pump 117 and / or the reductant pressurizing pump 118. For example, the controller 120 is configured to control the air pump 117 and the reductant pressurizing pump 118 to obtain a target mixture of air and reductant provided to the decomposition chamber 104. In some embodiments, the air pump 117 and the air source 115 may be omitted. In these embodiments, the dosing module 112 does not receive pressurized air.

[0034] The controller 120 includes a microprocessor, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), etc. or a combination thereof. The controller 120 includes a memory, which may include, but is not limited to, an electronic, optical, magnetic, or any other storage device or transmission device capable of providing program instructions to the processor, ASIC, FPGA, etc. The memory includes a memory chip, an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a flash memory, or any other suitable memory from which the controller 120 can read instructions. The instructions include code from any suitable programming language.

[0035] The SCR unit 106 (eg, CuSCR, FeSCR, VSCR) is configured to accelerate the removal of ammonia and NO in the exhaust gas. x NO x Reduction of NO to diatomic nitrogen, water and / or carbon dioxide helps reduce NO x Emissions. The SCR unit 106 includes an inlet and an outlet, the inlet being in fluid communication with the decomposition chamber 104, the exhaust gas and the reductant being received from the inlet, and the outlet being in fluid communication with an end of the exhaust system 190. The SCR unit 106 may include a copper SCR unit (e.g., a CuSCR). For example, the copper SCR unit may include copper. The SCR unit 106 may include an iron SCR unit (e.g., a FeSCR). For example, the iron SCR unit may include iron.

[0036] The exhaust system 190 may also include an oxidation catalyst (eg, a diesel oxidation catalyst (DOC)) in fluid communication with the exhaust system 190 (eg, downstream of the SCR unit 106 or upstream of the DPF 102) to oxidize hydrocarbons and carbon monoxide in the exhaust gas.

[0037] In some embodiments, the DPF 102 is positioned downstream of the decomposition chamber 104. For example, the DPF 102 and the SCR unit 106 may be combined into a single unit. In some embodiments, the dosing module 112 is alternatively positioned downstream of the turbocharger or upstream of the turbocharger.

[0038] The sensor 150 is coupled to the exhaust system 190 to detect a condition of the exhaust gas flowing through the exhaust system 190. In some embodiments, the sensor 150 includes a portion disposed within the exhaust system 190; for example, the end of the sensor 150 extends into a portion of the exhaust system 190. In other embodiments, the sensor 150 receives the exhaust gas through another conduit (e.g., one or more sample tubes extending from the exhaust system 190). Although the sensor 150 is depicted as being positioned downstream of the SCR unit 106, it should be understood that the sensor 150 may be positioned at any other location of the exhaust system 190, including upstream of the DPF 102, within the DPF 102, between the DPF 102 and the decomposition chamber 104, within the decomposition chamber 104, between the decomposition chamber 104 and the SCR unit 106, within the SCR unit 106, or downstream of the SCR unit 106. Additionally, two or more sensors 150 may be used to detect conditions of the exhaust, such as two, three, four, five, or six sensors 150, each of which is located at one of the aforementioned locations of the exhaust system 190. In some embodiments, sensor 150 may be omitted.

[0039] III. Example System for Capturing and Deactivating Platinum Emissions Figure 2 A block diagram of an example system 100 (e.g., an aftertreatment system) for capturing and deactivating platinum emissions (e.g., capturing and deactivating platinum 225 in a flow of emissions 230 (e.g., exhaust gas)) is shown. The system 100 includes a dosing module 112 (e.g., a doser, etc.). The dosing module 112 is configured to dosing a reductant (e.g., urea) into a decomposition chamber 104. The system 100 includes an SCR unit 106. In some embodiments, the reductant is injected upstream of the SCR unit 106. The SCR unit 106 is fluidly disposed downstream of the dosing module 112. For example, exhaust gas can flow from the dosing module 112 to the SCR unit 106. The SCR unit 106 is in fluid communication with the dosing module 112. The dosing module 112 is fluidly disposed upstream of the SCR unit 106.

[0040] The system 100 has a diesel oxidation catalyst (DOC) 205 (e.g., an oxidation catalyst, a platinum-containing catalyst, etc.). In other embodiments, the system 100 does not include the DOC 205. The DOC 205 is fluidly disposed upstream of the dosing module 112. The dosing module 112 is fluidly disposed downstream of the DOC 205. For example, exhaust gas can flow from the DOC 205 to the dosing module 112. The DOC 205 is in fluid communication with the dosing module 112. The DOC 205 is fluidly disposed upstream of the SCR unit 106. The SCR unit 106 is fluidly disposed downstream of the DOC 205. For example, exhaust gas can flow from the DOC 205 to the SCR unit 106. The DOC 205 is in fluid communication with the SCR unit 106. The DOC 205 may include or contain platinum 225. For example, the DOC 205 may include a platinum-containing DOC.

[0041] The system 100 has a conduit 210. The conduit 210 may include a decomposition chamber 104. The conduit 210 includes a portion of the system 100 between the DOC 205 and the SCR unit 106. The conduit 210 may include a portion of the system 100 that fluidly couples the DOC 205 to the SCR unit 106. The conduit 210 may include a portion of the system 100 that fluidly couples the dosing module 112 to the SCR unit 106. The dosing module 112 is configured to dosing a reductant into the conduit 210. The conduit 210 fluidly connects the dosing module 112 to the SCR unit 106. The conduit 210 is fluidly disposed downstream of the DOC 205. The DOC 205 is fluidly disposed upstream of the conduit 210. The conduit 210 is fluidly disposed upstream of the SCR unit 106. The SCR unit 106 is fluidly disposed downstream of the conduit 210. The conduit 210 may fluidly connect the DOC 205 to the SCR unit 106. The conduit 210 may be fluidly coupled to the DOC 205. The conduit 210 may be fluidly coupled to the SCR unit 106.

[0042] The conduit 210 has a coating 215 disposed on a surface (e.g., a portion of the surface) of the conduit 210. The coating 215 may be disposed on an interior (e.g., an inner surface) of the conduit 210. The coating 215 may be disposed uniformly or non-uniformly on the surface of the conduit 210. For example, the coating 215 may have a uniform thickness or a non-uniform thickness across the surface of the conduit 210. The thickness of the coating 215 may be different at different locations in the system 100. The coating 215 may have a variable thickness along the length of the surface of the conduit 210. For example, the thickness of the coating 215 on the surface of the conduit 210 near the DOC 205 may be greater than, less than, or equal to the thickness of the coating 215 on the surface of the conduit 210 near the SCR unit 106. The thickness of the coating 215 on the surface of the conduit 210 near the dosing module 112 may be greater than, less than, or equal to the thickness of the coating 215 on the surface of the conduit 210 near the SCR unit 106.

[0043] The coating 215 may be disposed on a portion of the conduit 210. The coating 215 may be disposed on an upper portion or a lower portion of the conduit 210. The coating 215 may be disposed on a surface of the conduit 210 between the DOC 205 and the dosing module 112. For example, the coating 215 may be disposed upstream of the dosing module 112 and downstream of the DOC 205. The coating 215 may be disposed on a surface of the conduit 210 between the dosing module 112 and the SCR unit 106. For example, the coating 215 may be disposed upstream of the SCR unit 106 and downstream of the dosing module 112. The coating 215 may be disposed downstream of the dosing module 112 so that urea and ammonia (NH3) may pass through the exhaust system 190.

[0044] The coating 215 may be thin and durable so that the coating 215 does not enter the interior of the SCR unit 106. The coating 215 may be thin and durable so that even in the presence of a reductant spray (e.g., urea spray), the coating 215 does not enter the interior of the SCR unit 106. The coating 215 may have a thickness between 5 μm and 500 μm.

[0045] The coating 215 is applied to surfaces downstream of the platinum-containing element. The coating 215 is applied to surfaces upstream of the body of the SCR unit 106. The coating 215 is applied to elements of the aftertreatment system 100 that are typically present in the aftertreatment system 100. The coating 215 is designed to capture the emitted platinum 225 before the platinum 225 reaches the interior of the SCR unit 106. The coating 215 can be disposed on a surface downstream of the DOC 205. The coating 215 can be disposed on the DPF 102.

[0046] At least a portion of an inlet 235 (e.g., an inlet face) of the SCR unit 106 may have a coating 215 disposed thereon. For example, the coating 215 may be disposed on a portion of the inlet 235 of the SCR unit 106. The inlet of the SCR unit 106 may include a portion of the SCR unit 106 exposed to exhaust gas from the decomposition chamber 104. The inlet 235 of the SCR unit 106 may include a portion of the SCR unit 106 exposed to exhaust gas from the conduit 210. The inlet 235 of the SCR unit 106 is fluidly disposed downstream of the decomposition chamber 104. The inlet 235 of the SCR unit 106 is fluidly disposed downstream of the conduit 210. The inlet 235 of the SCR unit 106 is fluidly disposed downstream of the DOC 205. The inlet 235 of the SCR unit 106 may be on an outer surface of the SCR unit 106 or a portion of an outer surface of the SCR unit 106. The coating 215 may be disposed on a surface of the inlet 235 of the SCR unit 106. The coating 215 may be disposed uniformly or non-uniformly on the surface of the inlet 235 of the SCR unit 106. For example, the coating 215 may have a uniform thickness across the surface of the inlet 235 of the SCR unit 106 or a non-uniform thickness.

[0047] A physical coating or a chemical coating may or may not be applied to the coating 215 applied directly to the inlet face of the SCR unit 106. Without the coating 215 applied, an element (e.g., Cu, P, etc.) that can poison the ability of the platinum 225 to oxidize NH3 may be spread over the inlet face of the SCR unit 106 as a thin layer.

[0048] The coating 215 is exposed to the exhaust (e.g., exhaust gas) passing through the conduit 210. For example, the coating 215 is exposed to the exhaust 230 containing platinum 225. The exhaust 230 may include platinum vapor. The platinum vapor may adhere to the coating 215. For example, due to high surface area and / or chemical bonding, the platinum vapor may adhere to the coating 215. The coating 215 is exposed to the exhaust leading to the SCR unit 106. The surface of the coating 215 is exposed to the exhaust passing through the conduit 210. The coating 215 may be exposed to the vapor containing platinum. The platinum 225 from the exhaust 230 may originate from the DOC 205. The platinum 225 from the exhaust 230 may originate from a platinum-containing catalyst (e.g., a Pt-containing catalyst, a platinum group metal catalyst, a PGM catalyst, etc.).

[0049] The platinum 225 may migrate downstream from the DOC 205. For example, the exhaust 230 containing the platinum 225 may flow from the DOC 205 through the conduit 210. The exhaust 230 containing the platinum 225 may flow from the DOC 205 to the inlet 235 of the SCR unit 106. The platinum 225 may be entrained in the exhaust 230. For example, the platinum 225 may be carried in the exhaust 230 as the exhaust 230 flows through the conduit 210. The platinum 225 may be carried in the exhaust 230 as the exhaust 230 flows from the DOC 205 to the SCR unit 106. The platinum 225 may be deposited onto the coating 215. For example, the platinum 225 may be deposited onto a surface of the coating 215. The platinum 225 may be deposited onto a portion of the coating 215.

[0050] The coating 215 may be exposed to an exhaust environment that further accelerates the deactivation of platinum. For example, the coating 215 may be exposed to the temperature, oxygen level, or NO2 level in the exhaust (eg, feed gas).

[0051] The coating 215 may include an element or compound that may inhibit or nullify the ability of platinum to act as an oxidizing agent or oxidant. The coating 215 may include an element or compound that may cause platinum to age or sinter. For example, the coating 215 may include at least one of copper, phosphorus, sodium, or silicon dioxide. The coating 215 may include an element or compound that may inhibit the ability of platinum to oxidize ammonia (NH3). The element or compound may react (e.g., chemically react) with the platinum 225 so that the platinum 225 does not act as an oxidant. The element or compound may cause rapid aging or sintering of the platinum. The element or compound may be spread over the surface of the conduit 210 as a thin layer.

[0052] The coating 215 is configured to capture platinum passing through the conduit 210. The platinum may be attached or bonded to the coating 215. For example, platinum 225 in the exhaust 230 may flow through the conduit 210 and be attached or bonded to the coating 215. The coating 215 may have a large surface area. The coating 215 may chemically bond with the platinum in the exhaust 230. The coating 215 captures the platinum 225 and prevents the platinum from migrating downstream to the SCR unit 106. The coating 215 may capture a portion (e.g., some or all) of the platinum passing through the conduit 210. The coating 215 disposed on the conduit 210 may capture a portion of the platinum 225 from the exhaust 230.

[0053] The coating 215 is configured to inactivate platinum passing through the conduit 210. For example, the coating 215 may inhibit or invalidate the ability of platinum to act as an oxidizing agent or oxidant. The coating 215 may inhibit the ability of platinum to oxidize ammonia. For example, the coating 215 may contain copper, phosphorus, or sodium, which may inhibit the ability of platinum to oxidize ammonia. The coating 215 may neutralize the oxidative activity of the platinum 225. For example, the coating 215 may neutralize the oxidative activity of the deposited platinum (e.g., NH3 oxidative activity) or promote the neutralization of the oxidative activity of the deposited platinum (e.g., NH3 oxidative activity). The coating 215 may have a property that promotes the neutralization of the NH3 oxidative activity of the deposited platinum. The coating 215 may cause platinum aging or sintering. For example, the coating 215 may contain silicon dioxide that may cause platinum 225 aging or sintering. The coating 215 may make the captured platinum harmless to the operation of the aftertreatment system 100. The coating 215 may protect the SCR unit 106 from degradation caused by platinum. The coating 215 may prevent the SCR unit 106 from losing efficiency.

[0054] The coating 215 may be configured to prevent the platinum 225 (e.g., some or all of the platinum) from migrating to the SCR unit 106. For example, the coating 215 may prevent the platinum 225 from entering the interior of the SCR unit 106. Without the coating 215, the platinum 225 from the DOC 205 or the exhaust 230 may reach or enter the SCR unit 106. The coating 215 may prevent the platinum from entering the interior of the SCR unit 106. The platinum may migrate from the DOC 205 via the exhaust through the conduit 210. The platinum may migrate from the upstream of the SCR unit 106 through the conduit 210 via the exhaust 230. When the platinum 225 migrates through the conduit 210, the platinum 225 may be captured by the coating 215 and deactivated by the coating 215. A portion of the platinum 225 may be prevented from migrating through the conduit 210. When the coating 215 is exposed to exhaust gas having platinum emissions therein, the coating 215 advantageously reduces interference of the platinum with downstream components. More specifically, the coating 215 advantageously reduces interference of the emissions and redeposited platinum with downstream components such as an SCR catalyst. In this manner, the coating 215 reduces interference of the platinum with the efficacy of the SCR catalyst. In some embodiments, the coating reduces migration of platinum to the SCR catalyst during a thermal event (e.g., a temperature exceeding a predetermined threshold) and / or under normal operating conditions (e.g., a temperature within a predetermined temperature range).

[0055] The system 100 may include a decomposition chamber 104. The decomposition chamber 104 may be fluidly disposed upstream of the SCR unit 106. The decomposition chamber 104 may be fluidly disposed downstream of the DOC 205. The decomposition chamber 104 may be fluidly coupled to the DOC 205. The decomposition chamber 104 may be fluidly coupled to the SCR unit 106. The decomposition chamber 104 may be fluidly coupled to the conduit 210.

[0056] At least a portion of the interior surface of the decomposition chamber 104 may have a coating 215 disposed thereon. The coating 215 may be disposed on the interior of the decomposition chamber 104. The coating 215 may be disposed uniformly or non-uniformly on the surface of the decomposition chamber 104. For example, the coating 215 may have a uniform thickness or a non-uniform thickness across the surface of the decomposition chamber 104. The thickness of the coating 215 may vary in the system 100. The coating 215 may have a variable thickness along the surface of the decomposition chamber 104. For example, the thickness of the coating 215 on the surface of the decomposition chamber 104 near the DOC 205 may be greater than, less than, or equal to the thickness of the coating 215 on the surface of the decomposition chamber 104 near the SCR unit 106. The thickness of the coating 215 on the surface of the decomposition chamber 104 near the dosing module 112 may be greater than, less than, or equal to the thickness of the coating 215 on the surface of the decomposition chamber 104 near the SCR unit 106.

[0057] The system 100 includes a mixer 220. In other embodiments, the system 100 does not include the mixer 220. The mixer 220 is fluidly disposed upstream of the SCR unit 106. The mixer 220 is fluidly disposed downstream of the dosing module 112. The mixer 220 is fluidly disposed downstream of the DOC 205. The mixer 220 is fluidly coupled to the DOC 205. The mixer 220 is fluidly coupled to the SCR unit 106. The mixer 220 is fluidly coupled to the conduit 210. The mixer 220 may include blades. The coating 215 may be disposed on the blades of the mixer 220.

[0058] At least a portion of the mixer 220 may have a coating 215 disposed thereon. The coating 215 may be disposed on the interior of the mixer 220. The coating 215 may be disposed uniformly or non-uniformly on the surface of the mixer 220. For example, the coating 215 may have a uniform thickness or a non-uniform thickness across the surface of the mixer 220. The thickness of the coating 215 may vary in the system 100. The coating 215 may have a variable thickness along the surface of the mixer 220. For example, the thickness of the coating 215 on the surface of the mixer 220 near the DOC 205 may be greater than, less than, or equal to the thickness of the coating 215 on the surface of the mixer 220 near the SCR unit 106. The thickness of the coating 215 on the surface of the mixer 220 near the dosing module 112 may be greater than, less than, or equal to the thickness of the coating 215 on the surface of the mixer 220 near the SCR unit 106.

[0059] Figure 3A graph 300 of platinum contained in a catalyst (e.g., SCR catalyst, SCR unit 106) versus vehicle distance is shown. The platinum contained in the catalyst can be measured in parts per million by weight (ppmw) or other suitable measurements (e.g., parts per million by mass, mg / L, etc.). Vehicle distance is measured in miles or other suitable measurements (such as kilometers). Graph 300 shows example data points of an SCR unit 106 depicting a healthy field return. The amount of platinum contained in the catalyst can be quantified. For example, the platinum level of the inlet 235 of the SCR unit 106 can be analyzed. The SCR unit 106 is part of the aftertreatment system 100 of the vehicle. The SCR unit 106 is part of a vehicle that has traveled a distance corresponding to the vehicle distance.

[0060] Platinum was detected in the SCR unit 106 of the aftertreatment system 100 that did not include the coating 215. The presence of platinum in the SCR unit 106 may affect certain functions of the SCR unit 106. For example, the presence of platinum in the SCR unit 106 may reduce the performance of the SCR unit 106. The presence of platinum in the SCR unit 106 may reduce the efficiency of the SCR unit 106. The presence of platinum in the CuSCR may affect some catalyst functions.

[0061] Figure 4 The NO for an iron-based SCR (FeSCR) unit is shown x A graph 400 showing conversion versus temperature and N2O emissions versus temperature. x Conversion is measured in percent (%). Temperature is measured in degrees Celsius. N2O emissions are measured in parts per million (ppm). A first reference curve 405 is plotted for a FeSCR unit without platinum exposure, which shows NO x Conversion as a function of temperature. A first platinum exposure curve 410 is plotted for a FeSCR unit with platinum exposure, which shows NO x Conversion as a function of temperature. As shown, exposure to platinum results in NO x The conversion rate decreases at 400°C or above (e.g., 400°C, 450°C, 500°C, 550°C, etc.). x The conversion rate may be undesirable because the SCR unit 106 may be designed to convert NO x .

[0062] A second reference curve 415 is plotted for a FeSCR unit without platinum exposure, which shows N2O emissions as a function of temperature. A second platinum exposure curve 420 is plotted for a FeSCR unit with platinum exposure, which shows N2O emissions as a function of temperature. As shown, platinum exposure may cause N2O emissions to increase above 250°C to 450°C (e.g., 250°C, 300°C, 350°C, 400°C, 450°C, etc.). Increased N2O emissions may be undesirable because N2O is a greenhouse gas and a regulated pollutant.

[0063] Figure 5 An untreated catalyst (e.g., an untreated platinum-containing catalyst) is shown. The untreated catalyst contains platinum that migrates downstream in the aftertreatment system. Due to the inclusion of a FeSCR inlet zone for reducing NO, a system layout such as DOC 205 upstream of SCR unit 106, a complex DOC coating with a platinum-rich rear zone, and active SCR de-SO x strategy, engine aging experience, the impact and prevalence of platinum migration may increase.

[0064] Two platinum transport mechanisms can occur in untreated catalysts. Platinum transport mechanisms can include PtO x Evaporation of (e.g., platinum oxide) or migration of washcoat particles. x The evaporation of may include a platinum transport mechanism whereby the oxidized platinum evaporates and the oxidized platinum vapor emissions 510 flow downstream to the SCR unit 106. The washcoat particle migration may include a platinum transport mechanism whereby the washcoat particles 505 may break away from a substrate (e.g., an alumina carrier, an alumina substrate) and flow downstream to the SCR unit 106.

[0065] Figure 6 A treated catalyst (e.g., a treated platinum-containing catalyst) is shown. The platinum-containing catalyst may be treated prior to installation in the aftertreatment system 100. The treatment may be applied to reduce platinum emissions during operation of the aftertreatment system 100. The treatment may allow for reduced or no platinum emissions. For example, the treated catalyst advantageously reduces the transport of platinum (e.g., PtO x evaporation or migration of washcoat particles).

[0066] Figure 7A flow chart of a process 700 (e.g., method, procedure, etc.) for applying a heat treatment and / or gas flow treatment is shown. In some embodiments, the process 700 is performed by the controller 120. The heat treatment may include exposing the platinum-containing catalyst to a high temperature (e.g., higher than the highest temperature encountered in the operation of the system). The heat treatment may reduce subsequent platinum emissions from the treated element. The duration of the heat treatment may be less than 1 hour at a temperature above 650°C and 2 hours to 6 hours at a temperature below 650°C. This temperature exposure may occur during the catalyst manufacturing process at the powder stage or on the coated monolith, after manufacturing (e.g., in a dedicated furnace or burner), or on the final engine before installing downstream elements. In addition to a separate heat treatment, high temperature treatment in a controlled atmosphere may bring additional reductions in platinum emissions. Examples of heat treatments in a controlled atmosphere may include high temperature treatments in a mixture of air and steam. Examples of heat treatments in a controlled atmosphere may include high temperature treatments in a strongly oxidizing atmosphere (e.g., a high O2 partial pressure or the presence of an oxidant such as ozone or NO2).

[0067] Airflow treatment (e.g., air blowing treatment) may include exposing the platinum-containing catalyst to high velocity air. Airflow treatment may remove loosely bound washcoat particles and reduce subsequent migration of platinum to downstream components. The flow rate may be significantly higher than the maximum flow rate encountered in operation. The air flow rate may be high enough to remove any loose particles, but not so high as to damage the catalyst or the coating. Airflow treatment and heat treatment may be applied separately or in combination.

[0068] Process 700 begins in frame 705 by determining whether the aftertreatment system includes an SCR unit 106 downstream of one or more platinum-containing catalysts (e.g., PGM catalysts). If the SCR unit 106 is not downstream of the one or more platinum-containing catalysts, then no action is applied in frame 710. If the SCR unit 106 is downstream of the one or more platinum-containing catalysts, then process 700 continues to frame 715 by determining whether a diesel particulate filter is between the one or more platinum-containing catalysts and the SCR unit 106.

[0069] If the diesel particulate filter is not between one or more platinum-containing catalysts and the SCR unit 106, airflow treatment and heat treatment are selectively applied to one or more platinum-containing catalysts. Process 700 continues to frame 720 to determine whether the FeSCR is the first SCR element (e.g., the first element in a group of SCR elements that receive exhaust gas, the first element in the SCR unit). If the FeSCR is not the first SCR element, process 700 continues to frame 725 to apply airflow and weak heat treatment to one or more platinum-containing catalysts. If the FeSCR is the first SCR element, process 700 continues to frame 730 to apply airflow and strong heat treatment to one or more platinum-containing catalysts.

[0070] If the diesel particulate filter is between one or more platinum-containing catalysts and the SCR unit 106, then the one or more platinum-containing catalysts are selectively heat treated. Process 700 continues to box 735 to determine whether the FeSCR is the first SCR element. If the FeSCR is not the first SCR element, process 700 continues to box 740 to apply a weak heat treatment to one or more platinum-containing catalysts. If the FeSCR is the first SCR element, process 700 continues to box 745 to apply a strong heat treatment to one or more platinum-containing catalysts.

[0071] IV. Configuration of Example Embodiments Although this specification contains many specific implementation details, these should not be interpreted as limitations on the scope of the content that can be claimed, but should be interpreted as descriptions of features that are unique to specific implementations. Certain features described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. On the contrary, the various features described in the context of a single implementation can also be implemented individually or in any suitable sub-combination in multiple implementations. Moreover, although features can be described as working in certain combinations and even initially claimed as such, one or more features from the claimed combination can be deleted from the combination in some cases, and the claimed combination can involve a sub-combination or a deformation of the sub-combination.

[0072] As utilized herein, the term "substantially" and similar terms are intended to have a broad meaning consistent with common and accepted usage by those of ordinary skill in the art to which the subject matter of the present disclosure belongs. Those skilled in the art who review the present disclosure should understand that these terms are intended to allow description of certain features described and claimed without limiting the scope of these features to the precise numerical ranges provided. Therefore, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the present invention as described in the appended claims.

[0073] As used herein, the terms "coupled," "connected," and the like mean the joining of two components directly or indirectly to one another. Such joining may be fixed (e.g., permanent) or movable (e.g., removable or releasable). Such joining may be achieved by the two components, or the two components and any additional intermediate components, being integrally formed as a single unitary body with one another, or by the two components, or the two components and any additional intermediate components, being attached to one another.

[0074] As used herein, the terms "fluidically coupled," "in fluid communication," and similar terms mean that two components or objects have a passage formed between the two components or objects in which a fluid (e.g., exhaust, water, air, gaseous reductant, gaseous ammonia, etc.) can flow with or without interfering with the components or objects. Examples of fluid couplings or structures for achieving fluid communication may include pipes, channels, or any other suitable components for achieving the flow of a fluid from one component or object to another component or object.

[0075] It is important to note that the structure and arrangement of the systems shown in the various exemplary embodiments are illustrative and non-restrictive in nature. All changes and modifications within the spirit and / or scope of the described embodiments need to be protected. It should be understood that some features may not be necessary, and embodiments without various features may be considered to be within the scope of the present application, which scope is defined by the subsequent claims. When the language "a portion" is used, the item may include a portion and / or the entire item unless explicitly stated to the contrary.

Claims

1. A post-processing system, include: Distribution module; a selective catalytic reduction (SCR) unit, the SCR unit being fluidly disposed downstream of the dosing module; and a conduit fluidly connecting the dosing module to the SCR unit, the conduit having a coating disposed on a surface thereof, the coating: exposed to exhaust passing through the conduit and the SCR unit; and The device is configured to capture platinum passing through the conduit and inactivate the platinum.

2. The post-processing system according to claim 1, further comprising: include: A decomposition chamber is fluidly disposed upstream of the SCR unit, at least a portion of an inner surface of the decomposition chamber having the coating disposed thereon.

3. The post-processing system according to claim 1, further comprising: include: A mixer is fluidly disposed upstream of the SCR unit and fluidly disposed downstream of the dosing module, at least a portion of the mixer having the coating disposed thereon. 4 . The aftertreatment system of claim 1 , wherein at least a portion of an inlet of the SCR unit has the coating disposed thereon.

5. The aftertreatment system of claim 1, wherein the coating comprises at least one of copper, phosphorus, sodium, or silicon dioxide.

6. The post-processing system according to claim 1, further comprising: include: Diesel oxidation catalysts (DOCs) containing platinum; and The coating is disposed on a surface of the conduit downstream from the DOC. 7 . The aftertreatment system of claim 6 , wherein the DOC is fluidly disposed upstream of the SCR unit. 8 . The aftertreatment system of claim 6 , further comprising a diesel particulate filter (DPF), wherein the coating is disposed on the DPF. 9 . The aftertreatment system of claim 8 , wherein the DPF is disposed between the DOC and the SCR unit.

10. A post-processing system, include: Platinum-containing diesel oxidation catalyst (DOC), a conduit fluidly coupled to the DOC, the conduit having a coating disposed on a surface thereof, the coating: exposed to exhaust passing through the conduit and the SCR unit; and The device is configured to capture platinum passing through the conduit and inactivate the platinum.

11. The post-treatment system of claim 10, wherein the conduit includes a decomposition chamber disposed therein, at least a portion of an inner surface of the decomposition chamber having the coating disposed thereon.

12. The aftertreatment system of claim 11, further comprising a dosing module coupled to the decomposition chamber, wherein the coating is disposed downstream of the dosing module.

13. The aftertreatment system of claim 10, further comprising a mixer fluidly coupled to the conduit, at least a portion of the mixer having the coating disposed thereon.

14. The aftertreatment system of claim 10, further comprising a selective catalytic reduction (SCR) unit fluidly coupled to the conduit, wherein an inlet of the SCR unit has the coating disposed thereon.

15. The aftertreatment system of claim 10, wherein the coating is disposed on a surface of the conduit downstream of the DOC.

16. A system, include: engine; and an aftertreatment system in exhaust receiving communication with the engine, the aftertreatment system comprising: -- Distribution module; - a selective catalytic reduction (SCR) unit, the SCR unit being fluidly disposed downstream of the dosing module; and a conduit fluidly connecting the dosing module to the SCR unit, the conduit having a coating disposed on a surface thereof, the coating: exposed to the exhaust through the conduit and the SCR unit; and The device is configured to capture platinum passing through the conduit and inactivate the platinum.

17. The system of claim 16, further comprising a decomposition chamber fluidly disposed upstream of the SCR unit, at least a portion of an interior surface of the decomposition chamber having the coating disposed thereon; Wherein the dosing module is coupled to the decomposition chamber.

18. The system of claim 16, wherein the coating is disposed non-uniformly on the surface of the conduit such that a thickness of the coating proximate the dosing module is different than a thickness of the coating proximate the SCR unit.

19. The system of claim 16, wherein the coating is uniformly disposed on the surface of the catheter.

20. The system of claim 16, further comprising a diesel oxidation catalyst (DOC) containing platinum, said DOC being fluidly disposed upstream of said dosing module; wherein the conduit fluidly connects the DOC to the SCR unit; and wherein the coating is disposed non-uniformly on the surface of the conduit such that a thickness of the coating proximate the DOC is different from a thickness of the coating proximate the SCR unit.

21. A method for treating a post-processing system, the method include: determining, by a controller, that a selective catalytic reduction (SCR) unit of the aftertreatment system is downstream of one or more platinum-containing catalysts; determining, by the controller, whether a diesel particulate filter is between the one or more platinum-containing catalysts and the SCR unit; In response to determining that the diesel particulate filter is not between the one or more platinum-containing catalysts and the SCR unit, selectively applying, by the controller, an airflow treatment and a heat treatment to the one or more platinum-containing catalysts; and In response to determining that the diesel particulate filter is between the one or more platinum-containing catalysts and the SCR unit, a heat treatment is selectively applied by the controller to the one or more platinum-containing catalysts.

22. The method according to claim 21, further comprising: include: determining, by the controller, whether an iron SCR is a first SCR element of the SCR unit in response to determining that the diesel particulate filter is not between the one or more platinum-containing catalysts and the SCR unit; applying, by the controller, the gas flow treatment and the mild heat treatment to the one or more platinum-containing catalysts in response to determining that the iron SCR is not the first SCR element; and In response to determining that the iron SCR is the first SCR element, applying the gas flow treatment and the intense heat treatment to the one or more platinum-containing catalysts by the controller.

23. The method according to claim 21, further comprising: include: In response to determining that the diesel particulate filter is between the one or more platinum-containing catalysts and the SCR unit, determining, by the controller, whether an iron SCR is a first SCR element of the SCR unit; applying, by the controller, a mild heat treatment to the one or more platinum-containing catalysts in response to determining that the iron SCR is not the first SCR element; and In response to determining that the iron SCR is the first SCR element, an enhanced heat treatment is applied by the controller to the one or more platinum-containing catalysts.

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