Application of synergized-PGM with ultra-low PGM loadings as close-coupled three-way catalysts for internal combustion engines

Synergized platinum group metals (SPGM) with ultra-low PGM loadings employed as close-coupled (CC) three-way catalysts (TWC) systems with varied material compositions and configurations are disclosed. SPGM CC catalysts in which ZPGM compositions of binary or ternary spinel structures supported onto support oxides are coupled with commercialized PGM UF catalysts and tested under Federal Test Procedure FTP-75 within TGDI and PI engines. The performance of the TWC systems including SPGM CC (with ultra-low PGM loadings) catalyst and commercialized PGM UF catalyst is compared to the performance of commercialized PGM CC and PGM UF catalysts. The disclosed TWC systems indicate that SPGM CC TWC catalytic performance is comparable or even exceeds high PGM-based conventional TWC catalysts, with reduced tailpipe emissions.

BACKGROUND

Field of the Disclosure

The present disclosure relates generally to three-way catalyst (TWC) systems, and more particularly, to synergized-PGM TWC catalysts with ultra-low PGM loadings employed in close-coupled configurations for reduction of emissions from engine exhaust systems.

Background Information

Three-way catalyst (TWC) systems continue to be implemented as the primary emission control strategy for internal combustion engines within vehicles. However, a period of rapidly evolving production road maps for engine/combustion improvements that are tied to energy efficiency has recently begun by the automotive industry. Associated catalytic improvements will need to go beyond the fine tuning of platinum group metals (PGM) usage and rare earth (RE) metals used as oxygen storage materials (OSM) and will present important challenges to catalyst developers.

The trend toward more stringent tailpipe regulations, noted from the global tightening of the light and heavy duty emission standards, have led to important improvements in the development of modern catalysts including: improved fuel economy and reduction of greenhouse gas emissions requirements that establish lower exhaust temperatures; and material supply issues related to the supply and demand of PGM materials as a result of their availability and price volatility. As changes in the formulation of catalysts continue to increase the cost of TWC systems, the need for catalysts of significant catalytic performance has directed efforts toward the development of catalytic materials capable of providing the required synergies to achieve greater catalytic performance. Additionally, compliance with ever stricter environmental regulations, and the need for lower manufacturing costs require new types of TWC systems. Therefore, there is a continuing need to provide TWC systems, employing reduced amounts of PGM catalyst materials and that are free of RE metals, which exhibit catalytic properties substantially similar to or exceeding the catalytic properties exhibited by conventional TWC systems employing standard amounts of PGM catalyst materials and RE metals.

SUMMARY

The present disclosure describes three-way catalyst (TWC) systems including synergized ultra-low platinum group metals (PGM) loadings close-coupled (CC) catalysts. The ultra-low PGM loadings CC catalysts within the TWC systems are synergized with Zero-PGM (ZPGM) catalyst material compositions comprising spinel oxide materials. The catalyst material compositions within the ZPGM layers of the SPGM CC catalysts include binary or ternary spinel structures supported onto support oxides. The catalyst material compositions within the PGM layers include variable platinum (Pt)/palladium (Pd)/rhodium (Rh) with ultra-low concentrations within a range of about 1 g/ft3to about 10 g/ft3supported onto support oxides.

In some embodiments, a variety of TWC systems are configured to assess their catalytic performance measuring tailpipe emissions according to the U.S. Federal Test Procedure (FTP-75) protocol. In these embodiments, the TWC systems are configured to include commercially available underfloor (UF) catalysts and SPGM (with ultra-low PGM) CC catalysts. Further to these embodiments, the configured TWC systems, including the SPGM CC catalysts, are mechanically coupled to and in fluidic communication with an internal combustion engine, such as, for example a Tier 2 bin 4 turbo gasoline direct injection (TGDI) engine or a naturally aspirated port-injection (PI) engine, amongst others, for emission certification testing according to FTP-75 protocol.

In other embodiments, a standard TWC system is configured with commercially available PGM-based OEM CC, and PGM-based OEM and aftermarket UF catalysts. In these embodiments, the standard TWC system is mechanically coupled to and in fluidic communication with substantially similar engines used for testing the aforementioned TWC systems including ultra-low loading SPGM CC catalysts according to FTP-75 protocol.

In further embodiments, prior to emission testing according to FTP-75 protocol, the OEM CC, OEM UF, and SPGM CC catalysts within the TWC systems are aged on an engine bench employing a standard multi-mode aging cycle at bed temperatures of about 1000° C. and about 900° C. for about 50 hours, respectively, for CC and UF catalysts.

In some embodiments, catalytic efficiency of SPGM CC catalyst, measured downstream at the tailpipe (weighted bag results) for the aforementioned TWC systems is assessed according to FTP-75 protocol and further compared with the weighted emissions measured for the CC high PGM OEM catalysts.

In one embodiment, the disclosure is directed to a catalytic system for treating an exhaust stream of a combustion engine, comprising a combustion engine; a close-coupled catalytic converter configured to accept at least one exhaust gas stream from said combustion engine, wherein the close-coupled catalytic converter comprising a synergized platinum group metal catalyst comprising a spinel catalyst composition and an ultra-low platinum group metal catalyst material, and wherein the platinum group metal catalyst material has a platinum group metal concentration of about 1 g/ft3to about 10 g/ft3; and an underfloor catalytic converter downstream of, and, in fluid communication with said close-coupled catalytic converter, wherein the underfloor catalytic converter comprising a platinum group metal catalyst.

In one embodiment, the underfloor catalytic converter has a platinum group metal concentration of about 10 to 100 g/ft3, and more typically from about 15 to 60 g/ft3.

In some embodiments, the platinum group metal of the underfloor catalytic converter is selected from the group consisting of platinum, palladium, ruthenium, iridium, and rhodium. In a preferred embodiment, the platinum group metal of the underfloor catalytic converter comprises a combination of platinum and rhodium.

The spinel catalyst composition of the synergized platinum group metal catalyst may comprise a binary spinel having the general formula AxB3-xO4wherein X is from 0.01 to 2.99, and A and B are selected from the group consisting of sodium, potassium, calcium, barium, zinc, cadmium, aluminum, magnesium, manganese, nickel, copper, cobalt, iron, chromium, titanium, cerium, strontium, lanthanum, praseodymium, neodymium, samarium, indium, and mixtures thereof.

For example, the binary spinel may comprises a Ni—Fe spinel, for example, a Ni—Fe spinel structure comprising Ni0.5Fe2.5O4.

In some embodiments, the spinel catalyst composition comprises at least one substrate, and a catalyst composition comprising a spinel oxide having the formula AXBYM3-X-Ywhere X is from about 0.01 to about 1.99 and Y is from about 0.01 to about 1.0, and wherein A, B, and M are different from each other, and are selected from the group consisting of sodium, potassium, calcium, barium, zinc, cadmium, aluminum, magnesium, manganese, nickel, copper, cobalt, iron, chromium, titanium, cerium, strontium, lanthanum, praseodymium, neodymium, samarium, indium, and mixtures thereof.

In one embodiment, the spinel catalyst composition is supported onto a support oxide selected from the group consisting of Al2O3, doped Al2O3, ZrO2, doped ZrO2, SiO2, doped SiO2, TiO2, doped TiO2, doped Al2O3—ZrO2, Nb2O5, and mixtures thereof.

In one embodiment, the spinel catalyst composition is deposited onto a substrate as a washcoat layer, and the ultra-low platinum group metal catalyst material is deposited onto said washcoat layer as an overcoat layer. An example of a suitable substrates on which the spinel catalyst composition is deposited is a ceramic, such as cordierite.

In one embodiment, the platinum group metal of the ultra-low platinum group metal catalyst is selected from the group consisting of platinum, palladium, ruthenium, iridium, and rhodium. In a preferred embodiment, the platinum group metal of the ultra-low platinum group metal catalyst comprises a combination of platinum and rhodium. In one particular embodiment, the amount of platinum in the ultra-low platinum group metal catalyst material is from about 1 to 10 g/ft3, and the amount of rhodium in the ultra-low platinum group metal catalyst material is from about 1 to 10 g/ft3.

In one embodiment, the ultra-low platinum group metal catalyst material comprises a combination of platinum and rhodium. Generally, the platinum and rhodium may be present in any ratio, such as between 1:10 and 10:1. In a preferred embodiment, the ultra-low platinum group metal catalyst material comprises a combination of platinum and rhodium that are present in a 1:1 ratio.

In one embodiment, the spinel catalyst composition comprises a Ni—Fe binary spinel structure supported onto a doped Al2O3—ZrO2support oxide.

In some embodiments, the underfloor catalytic converter comprises a combination of platinum and rhodium, wherein the total amount of platinum group metals in said underfloor catalytic converter is from about 15 to 25 g/ft3.

In some embodiments, the platinum group metal catalyst of the synergized platinum group metal catalyst is free of rare earth metals and oxygen storage materials.

Advantageously, embodiments of the catalytic system exhibit reductions in tailpipe emissions of NOx, CO, and THC in comparison to a similar system having a platinum group metal catalyst as the close-coupled catalytic converter in lieu of a synergized platinum group metal catalyst.

In a further embodiment, the disclosure provides a method for removing pollutants from an exhaust stream of a combustion engine. For example, the method may include the steps of introducing an exhaust stream of the combustion engine into a close-coupled catalytic converter comprising a synergized platinum group metal catalyst comprising a spinel catalyst composition and an ultra-low platinum group metal catalyst material, wherein the platinum group metal catalyst has a concentration of about 1 g/ft3to about 10 g/ft3to thereby at least partially catalytically convert NOx, CO, and THC; and introducing the at least partially catalytically converted exhaust stream into an underfloor catalytic converter comprising a platinum group metal catalyst.

In a preferred embodiment, the spinel catalyst composition comprises a Ni—Fe binary spinel structure supported onto a doped Al2O3—ZrO2support oxide.

Numerous other aspects, features and benefits of the present disclosure may be made apparent from the following detailed description taken together with the drawing figures.

DETAILED DESCRIPTION

The present disclosure is described herein in detail with reference to embodiments illustrated in the drawings, which form a part hereof. Other embodiments may be used and/or other modifications may be made without departing from the scope or spirit of the present disclosure. The illustrative embodiments described in the detailed description are not meant to be limiting of the subject matter presented.

Definitions

As used here, the following terms have the following definitions:

“Air-to-fuel ratio (AFR)” refers to the mass ratio of air to fuel present in a combustion process such as in an internal combustion engine.

“Calcination” refers to a thermal treatment process applied to solid materials, in presence of air, to bring about a thermal decomposition, phase transition, or removal of a volatile fraction at temperatures below the melting point of the solid materials.

“Catalyst” refers to one or more materials that may be of use in the conversion of one or more other materials.

“Catalytic converter” refers to a vehicle emissions control device that converts toxic pollutants in exhaust gas to less toxic pollutants by catalyzing a redox reaction (oxidation, reduction, or both).

“Catalyst system” refers to any system including a catalyst, such as a PGM catalyst or a ZPGM catalyst of at least two layers comprising a substrate, a washcoat and/or an overcoat.

“Close-coupled catalyst (CCC)” refers to a catalyst located in close proximity to the engine's exhaust manifold.

“Conversion” refers to the chemical alteration of at least one material into one or more other materials.

“U.S. Federal Test Procedure (FTP) emission test” refers to emission certification testing procedure of light-duty vehicles in the United States.

“Impregnation” refers to the process of imbuing or saturating a solid layer with a liquid compound or the diffusion of some element through a medium or substance.

“Incipient wetness (IW)” refers to the process of adding solution of catalytic material to a dry support oxide powder until all pore volume of support oxide is filled out with solution and mixture goes slightly near saturation point.

“Lambda” refers to a ratio of actual air-to-fuel ratio to a stoichiometric air-to-fuel ratio.

“Milling” refers to the operation of breaking a solid material into a desired grain or particle size.

“Original Equipment Manufacturer (OEM)” refers to a manufacturer of a new vehicle or a manufacturer of any part or component that is originally installed in a new vehicle's certified emission control system.

“Overcoat (OC) layer” refers to a catalyst layer of at least one coating that can be deposited onto at least one washcoat layer or impregnation layer.

“Spinel” refers to any minerals of the general formulation AB2O4where the A ion and B ion are each selected from mineral oxides, such as, for example magnesium, iron, zinc, manganese, aluminum, chromium, titanium, nickel, cobalt, or copper, amongst others.

“Substrate” refers to any material of any shape or configuration that yields a sufficient surface area for depositing a washcoat layer and/or an overcoat layer.

“Support oxide” refers to porous solid oxides, typically mixed metal oxides, which are used to provide a high surface area that aids in oxygen distribution and exposure of catalysts to reactants, such as, for example NOX, CO, and hydrocarbons.

“Synergized-PGM (SPGM) catalyst” refers to a PGM catalyst system that is synergized by a ZPGM compound employing different catalyst configurations.

“Three-way catalyst (TWC)” refers to a catalyst that performs the three simultaneous tasks of reduction of nitrogen oxides to nitrogen and oxygen, oxidation of carbon monoxide to carbon dioxide, and oxidation of unburnt hydrocarbons to carbon dioxide and water.

“Underfloor (UF) catalyst” refers to a catalyst that is incorporated into the exhaust system of a motor vehicle, typically located beneath the floor of vehicle, mechanically coupled downstream to a close-coupled (CC) catalyst.

“Washcoat (WC) layer” refers to a catalyst layer of at least one coating, including at least one oxide solid that can be deposited onto a substrate.

“Zero-PGM (ZPGM) catalyst” refers to a catalyst completely or substantially free of platinum group metals (PGM).

Description of the Disclosure

The present disclosure describes synergized platinum group metals (SPGM) close-coupled (CC) three-way catalysts that are produced having a catalyst configuration that includes an ultra-low PGM composition synergized with a spinel-based ZPGM composition, which is free of rare-earth (RE) metals compositions. These SPGM CC catalysts are incorporated within engine systems as components of TWC converters that are part of TWC systems for controlling and reducing engine exhaust emissions. The conversion performance of these TWC systems is assessed and compared using the driving phases described in the U.S. Federal Test Procedure (FTP-75) protocol (2014).

TWC System Configuration

FIG. 1is a graphical representation illustrating a configuration for three-way catalyst (TWC) systems including close-coupled (CC) and underfloor (UF) catalysts, according to an embodiment. InFIG. 1, engine system100includes engine102and TWC system104. TWC system104further includes close-coupled (CC) catalyst106and underfloor (UF) catalyst108. InFIG. 1, engine102is mechanically coupled to and in fluidic communication with TWC system104. In TWC system104, CC catalyst106is mechanically coupled to and in fluidic communication with UF catalyst108.

In some embodiments, CC catalyst106is implemented as either a PGM commercialized catalyst including a high PGM loading or as a SPGM catalyst including ultra-low PGM loadings. In these embodiments, UF catalyst108is implemented as a PGM commercialized catalyst including a high PGM loading. Further to these embodiments, engine102can be implemented as an internal combustion engine employed within a motor vehicle, such as, for example a Tier 2 bin 4 turbo gasoline direct injection (TGDI) engine or a naturally aspirated port-injection (PI) engine, amongst others. In these embodiments, a variety of TWC systems can be configured to assess and compare the catalytic performance when employed with engine102.

In some embodiments, TWC system104, herein referred to as TWC system1, is implemented including a high PGM-based original equipment manufacturer (OEM) CC and OEM UF catalysts. In these embodiments, CC catalyst106is a high PGM-based OEM CC catalyst with a PGM loading of about 98 g/ft3palladium (Pd) and about 8 g/ft3rhodium (Rh), resulting in a total PGM loading of about 106 g/ft3and a substrate having a volume of about 1.7 L. Further to these embodiments, UF catalyst108is a high PGM-based OEM UF catalyst with a PGM loading of about 51 g/ft3Pd and about 8 g/ft3Rh, resulting in a total PGM loading of about 59 g/ft3and a substrate having a volume of about 1.3 L.

In some embodiments, TWC system104, herein referred to as TWC system2, is implemented including a high PGM-based OEM UF catalyst as described previously above in TWC system1and a SPGM CC catalyst with ultra-low PGM loadings. In these embodiments, CC catalyst106is a SPGM CC catalyst that includes a spinel-based ZPGM layer, coated with an ultra-low PGM layer of about 5 g/ft3platinum (Pt) and about 5 g/ft3Rh, resulting in a total PGM loading of about 10 g/ft3.

In some embodiments, TWC system104, herein referred to as TWC system3, is implemented including a commercially available high PGM-based CC and UF catalysts. In these embodiments, CC catalyst106is a high PGM-based CC catalyst with a PGM loading of about 55.9 g/ft3Pd and about 4.3 g/ft3Rh, resulting in a total PGM loading of about 60.2 g/ft3and a substrate having a volume of about 1.083 L. Further to these embodiments, UF catalyst108is a high PGM-based OF catalyst with a PGM loading of about 18 g/ft3Pt and about 4 g/ft3Rh, resulting in a total PGM loading of about 22 g/ft3and a substrate having a volume of about 1.083 L.

In some embodiments, TWC system104, herein referred to as TWC system4, is implemented including a PGM-based UF catalyst and a SPGM CC catalyst with ultra-low PGM loadings as described previously above in TWC system2. In these embodiments, UF catalyst108is a PGM-based OF catalyst with a PGM loading of about 12 g/ft3Pd and about 6 g/ft3Rh, resulting in a total PGM loading of about 18 g/ft3and a substrate of about 1.083 L. Further to these embodiments, CC catalyst106is a SPGM CC catalyst that includes spinel-based ZPGM layer, coated with an ultra-low PGM layer of about 5 g/ft3Pt and about 5 g/ft3Rh, resulting in a total PGM loading of about 10 g/ft3.

In some embodiments, TWC system1and TWC system2, are mechanically couple to and in fluidic communication with a TGDI engine used for testing the aforementioned TWC systems. In other embodiments, TWC system3and TWC system4are mechanically coupled to and in fluidic communication with a PI engine used for testing the aforementioned TWC systems.

SPGM CC Catalyst Configuration

In some embodiments, SPGM CC catalyst includes a substrate, a washcoat (WC) layer coated onto the substrate, and an overcoat (OC) layer coated onto the WC layer. In these embodiments, a PGM composition is implemented as an OC layer. Further to these embodiments, a ZPGM composition is implemented as a WC layer. Still further to these embodiments, different combinations of ZPGM and PGM composition provide different interactions between the ZPGM WC layer and the PGM OC layer within the SPGM CC catalyst configuration.

Material Composition of ZPGM Layer Employed within SPGM CC Catalysts

In some embodiments, a ZPGM composition employed within the WC layer includes binary spinel structures with a general formulation AXB3-XO4in which X is a variable for molar ratios within a range from about 0.01 to about 2.99. In these embodiments, A and B can be implemented as Na, K, Mg, Ca, Sr, Ba, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Al, Ti, Ce, La, Pr, Nd, Sm, In, or mixtures thereof, amongst others. Further to these embodiments, the binary spinel structures are supported onto support oxides. Examples of support oxides include alumina (Al2O3), doped Al2O3, zirconia (ZrO2), doped ZrO2, doped Al2O3—ZrO2, TiO2, Nb2O5, SiO2, or mixtures thereof, amongst others.

In an example, the ZPGM composition employed within the WC layer is implemented as a binary spinel structure of nickel (Ni) and iron (Fe). In this example, the Ni—Fe spinel structure is produced using a general formulation NiXFe3-XO4spinel in which X takes a value of about 0.5 for a Ni0.5Fe2.5O4binary spinel structure. Further to this example, the Ni0.5Fe2.5O4binary spinel structure is supported onto a doped Al2O3—ZrO2support oxide powder.

In other embodiments, a ZPGM composition employed within the WC layer includes ternary spinel structures with a general formulation AXBYM3-X-YO4in which X is a variable for different molar ratios within a range from about 0.01 to about 1.99, and Y is a variable for different molar ratios within a range from about 0.01 to about 1.0. In these embodiments, A, B, and M can be implemented as Na, K, Mg, Ca, Sr, Ba, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Al, Ti, Ce, La, In, or mixtures thereof, amongst others. Further to these embodiments, the ternary spinel structures are supported onto support oxides. Examples of support oxides include alumina (Al2O3), doped Al2O3, zirconia (ZrO2), doped ZrO2, doped Al2O3—ZrO2, TiO2, Nb2O5, SiO2, or mixtures thereof, amongst others.

Material Composition of PGM Layer Employed within SPGM CC Catalysts

In some embodiments, a PGM composition employed within the OC layer includes platinum (Pt), palladium (Pd), ruthenium (Ru), iridium (Ir), and rhodium (Rh), either by themselves, or in combinations thereof employing different loadings. In these embodiments, the PGM composition includes Pt/Rh with substantially similar loadings within a range from about 1 g/ft3to about 10 g/ft3supported onto a support oxide. In an example, the PGM composition employed within the OC layer includes PGM loadings of about 5 g/ft3Pt and about 5 g/ft3Rh supported onto a doped alumina support oxide powder.

SPGM CC Catalyst Configuration and Production

FIG. 2is a graphical representation illustrating a catalyst configuration of a synergized-PGM (SPGM) catalyst for CC applications, according to an embodiment. InFIG. 2, catalyst configuration200includes substrate202, ZPGM WC layer204, and PGM OC layer206. In some embodiments, ZPGM WC layer204is coated onto substrate202. In these embodiments, PGM OC layer206is coated onto ZPGM WC layer204.

In some embodiments, the ZPGM layer can be produced by employing any conventional catalyst synthesis methodologies. In these embodiments, the ZPGM layer is produced from powder comprising Ni—Fe spinel and doped Al2O3—ZrO2. Further to these embodiments, the preparation of powdered Ni—Fe spinel and support oxide begins with the mixing of an appropriate amount of Ni nitrate solution and Fe nitrate solution at an appropriate molar ratio that results in Ni0.5Fe2.5O4. Still further to these embodiments, the Ni—Fe nitrate solution is drop-wise added to the doped Al2O3—ZrO2(alumina-zirconia) support oxide powder via incipient wetness (IW) methodology. In these embodiments, the Ni—Fe/doped Al2O3—ZrO2support oxide powder is then dried at about 120° C. overnight and further calcined at a temperature within a range from about 600° C. to about 850° C. for about 5 hours. Further to these embodiments, the calcined material of Ni—Fe binary spinel and doped Al2O3—ZrO2is subsequently ground into fine grain powder, and further milled with water to produce a slurry. Still further to these embodiments, said slurry is coated onto the substrate and further dried and calcined at a temperature of about 650° C. from about 4 hours to about 5 hours to produce ZPGM WC layer204.

In an example, a SPGM CC catalyst with ultra-low PGM loadings, incorporated within TWC systems2and4, is produced including a ceramic substrate, such as, for example a 600/3.5 1.083 L substrate having a diameter (D) of 103.0 mm and a length (L) of 130.0 mm. Further to this example, the SPGM CC catalyst includes a ZPGM WC layer comprising a Ni—Fe binary spinel structure and doped Al2O3—ZrO2support oxide, as previously described above, and a PGM OC layer including Pt and Rh. In this example, the production of the PGM OC layer begins with the preparation of a mixed solution of Pt nitrate and Rh nitrate including PGM loadings of about 5 g/ft3Pt and about 5 g/ft3Rh. Further to this example, a mixture of doped alumina (Al2O3) and Ce-based oxygen storage material (OSM) at a ratio of about 1:1 by weight is milled separately and metallized with the Pt—Rh mixed nitrate solution to produce a slurry of PGM/(doped alumina +Ce-based OSM). Still further to this example, the slurry of PGM/(doped alumina+Ce-based OSM) is coated onto the ZPGM WC layer, and further dried and calcined at a temperature of about 550° C. for about 4 hours to produce the SPGM CC catalyst with ultra-low PGM loadings.

Multi-Mode Aging Cycle Procedure

In some embodiments and prior to emission testing according to FTP-75, aforementioned CC and UF catalysts within the TWC systems1,2,3, and4are aged under a standard multi-mode aging cycle on an engine bench. In these embodiments, the CC (PGM-based and SPGM) catalysts are aged under the multi-mode aging condition at a bed temperature of about 1000° C. for about 50 hours. Further to these embodiments, the UF catalysts are aged under the multi-mode condition at a bed temperature of about 900° C. for about 50 hours.

FIG. 3is a graphical representation illustrating a standard multi-mode aging cycle protocol employed for engine bench aging of SPGM CC catalysts, according to an embodiment. InFIG. 3, multi-mode aging cycle300illustrates the aging procedure for the aforementioned SPGM CC catalysts.

In some embodiments, the multi-mode aging cycle procedure includes four segments. In these embodiments, aging segment1is performed employing an exhaust gas flow with a stoichiometric fuel-air ratio (AFR) and flowrate of about 80 SCFM (standard cubic feet per minute) per catalytic converter for a time duration of about 40 seconds. Further to these embodiments, aging segment2is performed employing an exhaust gas flow with a rich AFR and a flowrate of about 80 SCFM for a time duration of about 6 seconds. Still further to these embodiments, aging segment3is performed employing an exhaust gas flow with a rich AFR and further employing a secondary air injection flow for a time duration of about 10 seconds, thereby producing chemical reaction-induced thermal excursions (exotherms) having a brick temperature controlled at about 40 mm at a temperature of about 900° C. within ±20° C. In these embodiments, aging segment4is performed employing an exhaust gas flow with a stoichiometric AFR with further employing a secondary air injection flow for a time duration of about 4 seconds.

U.S. Federal Test Procedure (FTP-75)

FIG. 4is a graphical representation illustrating driving phases of the U.S Federal Test Procedure (FTP-75) employed for testing, measuring, and diagnosing catalytic performance of TWC systems as described inFIGS. 1 and 2, according to an embodiment. InFIG. 4, FTP-75 protocol400includes cold start phase402, stabilized phase404, and hot start phase406.

In some embodiments, cold start phase402illustrates a phase of FTP-75 testing to measure tailpipe emissions and performance of the aforementioned TWC systems. In these embodiments, said driving phase is a cold start transient phase at ambient temperature of about 20° C. to about 30° C. performed for a time duration from zero to 505 seconds. Further to these embodiments, stabilized phase404illustrates a phase for driving conditions from about 506 seconds to about 1372 seconds performed after cold start phase402. Still further to these embodiments and after stabilized phase404is finished, the engine is stopped for about 10 minutes and then hot start phase406begins. In these embodiments, hot start phase406illustrates two segments of driving conditions performed after stabilized phase404as follows: (1) a hot soak performed for a minimum time duration of about 540 seconds or a maximum time duration of about 660 seconds, and (2) a hot start transient phase performed for a time duration from zero to about 505 seconds. Further to these embodiments, tailpipe emissions from each phase are collected in a separate bag, analyzed, and expressed in g/mile.

Test Engines and Engine Specifications for Implementation of the FTP-75 Test

In some embodiments and referring toFIG. 1, engine102is implemented as a TGDI engine with an electronically controlled twin-scroll turbocharger, dual overhead camshaft (DOHC) engine with continuously variable valve timing in which direct injection is performed employing a cam-driven high pressure fuel pump. In these embodiments, the TGDI engine includes a two-stage variable displacement oil pump, an air-to-air intercooling system, and a cast aluminum engine block. Major specifications of the TGDI engine are illustrated in Table 1, below.

In other embodiments and referring toFIG. 1, engine102is implemented as a PI engine with a die-cast aluminum engine block having 16 valves with dual variable valve timing (VVT-i), low friction technologies including an offset crankshaft and a valve train with roller rockers, three-stage variable oil pump, reduced-tension piston rings and an auxiliary belt drive. In these embodiments, the PI engine includes an acoustic control induction system that switches the length of the intake tract between two stages, based on RPM and throttle angle, to ensure a strong torque across a broad engine speed range. Further to these embodiments, the PI engine includes new tumble control valves that enhance combustion while the engine is cold and help to bring catalytic converters up to working temperature quickly. Still further to these embodiments, the tumble control valves, along with new 12-hole high atomizing long-nozzle fuel injectors, reduce the amount of fuel adhering to the intake ports to maximize fuel economy and reduce harmful emissions. Major specifications of the PI engine are illustrated in Table 2, below.

Tailpipe Weighted Emission Bag Results from FTP-75 Test—TGDI Engine

FIG. 5is a graphical representation illustrating weighted NOX(g/mile) values at tailpipe for TWC systems1and2(as described above) employed within a turbo gasoline direct injection (TGDI) engine using FTP-75 test protocol as described inFIG. 4, according to an embodiment. InFIG. 5, TP weighted NOXemission500includes TWC system1TP weighted NOX502and TWC system2TP weighted NOX510.

In some embodiments, TWC system1TP weighted NOx502includes three specific TP weighted NOXbars as follows: TP weighted NOx bar504, TP weighted NOx bar506, and TP weighted NOx bar508. In these embodiments, each NOXbar illustrates the FTP-75 bag results in g/mile of weighted NOXfor cold start phase402, stabilized phase404, and hot start phase406, respectively, obtained when measuring tailpipe NOXemissions associated with TWC system1. In other embodiments, TWC system2TP NOXweighted510includes three specific TP weighted NOXbars as follows: TP weighted NOXbar512, TP weighted NOXbar514, and TP weighted NOXbar516. In these embodiments, each NOXbar illustrates the FTP-75 bag results in g/mile of weighted NOXfor cold start phase402, stabilized phase404, and hot start phase406, respectively, obtained when measuring tailpipe NOXemissions associated with TWC system2.

In some embodiments, TP weighted NOXemissions collected in g/mile during implementation of FTP-75 testing associated with TWC systems1and2are detailed in Table 3, below. In these embodiments, TWC system2includes SPGM CC with ultra-low PGM loadings and OEM UF catalysts that exhibits lower tailpipe (TP) weighted NOXvalues as compared to TWC system1that includes OEM CC and UF catalysts. Further to these embodiments, TWC system2exhibits higher efficient TP NOXconversion than TWC system1. Still further to these embodiments and at the end of cold start phase402, TWC system1exhibits higher TP weighted NOXvalues than TWC system2. In these embodiments, both aforementioned TWC systems exhibit substantially similar TP weighted NOXvalues for stabilized phase404and hot start phase406. In summary, TWC system2exhibits a slightly improved performance in NOXreduction as compared with TWC system1, thereby confirming that employing a SPGM CC with ultra-low PGM loadings is as effective as employing a high PGM commercialized CC catalyst.

TABLE 3TP weighted NOxemission values associatedwith TWC systems 1 and 2, as illustrated in FIG. 5.TWCTP WEIGHTED NOxASSOCIATEDFTP-75 PHASESYSTEM[g/mile]ELEMENTCold start phase 40210.033504Stabilized phase 40410.001506Hot start phase 40610.005508Cold start phase 40220.027512Stabilized phase 40420.001514Hot start phase 40620.006516

FIG. 6is a graphical representation illustrating weighted CO (g/mile) values at tailpipe for TWC systems1and2(as described above) employed within a TGDI engine using FTP-75 test protocol as described inFIG. 4, according to an embodiment. InFIG. 6, TP weighted CO emission600includes TWC system1TP weighted CO602and TWC system2TP weighted CO610.

In some embodiments, TWC system1TP weighted CO602includes three specific weighted CO bars as follows: TP weighted CO bar604, TP weighted CO bar606, and TP weighted CO bar608. In these embodiments, each CO bar illustrates the FTP-75 bag results in g/mile of weighted CO for cold start phase402, stabilized phase404, and hot start phase406, respectively, obtained when measuring tailpipe CO emissions associated with TWC system1. In other embodiments, TWC system2TP weighted CO610includes three specific weighed CO bars as follows: TP weighted CO bar612, TP weighted CO bar614, and TP weighted CO bar616. In these embodiments, each CO bar illustrates the FTP-75 bag results in g/mile of weighted CO for cold start phase402, stabilized phase404, and hot start phase406, respectively, obtained when measuring tailpipe CO emissions associated with TWC system2.

In some embodiments, TP weighted CO emissions collected in g/mile during implementation of FTP-75 testing associated with TWC systems1and2are detailed in Table 4, below. In these embodiments, TWC system2includes an SPGM CC catalyst with ultra-low PGM loadings that exhibits overall significant CO conversion as compared to TWC system1that includes OEM CC and UF catalysts. Further to these embodiments, TWC system2exhibits higher efficient CO conversion than TWC system1. Still further to these embodiments, TP weighted CO values for TWC system2is significantly lower than TP weighted CO values for TWC system1for cold start phase402, stabilized phase404, and hot start phase406. These results confirm that employing an SPGM CC catalyst with about 10 g/ft3PGM loading is as efficient as employing a high PGM OEM CC catalyst with about 106 g/ft3PGM loading for CO conversion.

TABLE 4TP weighted CO emission values associated withTWC systems 1 and 2, as illustrated in FIG. 6.TWCTP WEIGHTED COASSOCIATEDFTP-75 PHASESYSTEM[g/mile]ELEMENTCold start phase 40210.270604Stabilized phase 40410.441606Hot start phase 40610.458608Cold start phase 40220.197612Stabilized phase 40420.297614Hot start phase 40620.200616

FIG. 7is a graphical representation illustrating weighted THC (g/mile) values at tailpipe for TWC systems1and2(as described above) employed within a TGDI engine using FTP-75 test protocol as described inFIG. 4, according to an embodiment. InFIG. 7, TP weighted THC emission700includes TWC system1TP weighted THC702and TWC system2TP weighted THC710.

In some embodiments, TWC system1TP weighted THC702includes three specific TP weighted THC bars as follows: TP weighted THC bar704, TP weighted THC bar706, and TP weighed THC bar708. In these embodiments, each THC bar illustrates the FTP-75 bag results in g/mile of weighted THC for cold start phase402, stabilized phase404, and hot start phase406, respectively, obtained when measuring tailpipe THC emissions associated with TWC system1. In other embodiments, TWC system2TP weighted THC710includes three specific TP weighted THC bars as follows: TP weighted THC bar712, TP weighted THC bar714, and TP weighted THC bar716. In these embodiments, each THC bar illustrates the FTP-75 bag results in g/mile of weighted THC for cold start phase402, stabilized phase404, and hot start phase406, respectively, obtained when measuring tailpipe THC emissions associated with TWC system2.

In some embodiments, TP weighted THC emissions collected in g/mile during implementation of FTP-75 testing associated with TWC systems1and2are detailed in Table 5, below. In these embodiments, TWC system2includes an SPGM CC catalyst with ultra-low PGM loadings that exhibits higher TP weighted THC values as compared to TWC system1that includes OEM CC and UF catalysts. Further to these embodiments, TWC system2exhibits lower performance in THC conversion than TWC system1.

TABLE 5TP weighted THC emission values associated withTWC systems 1 and 2, as illustrated in FIG. 7.TWCTP WEIGHTED THCASSOCIATEDFTP-75 PHASESYSTEM[g/mile]ELEMENTCold start phase 40210.028704Stabilized phase 40410.005706Hot start phase 40610.005708Cold start phase 40220.045712Stabilized phase 40410.012714Hot start phase 40620.012716

In some embodiments, TWC system1TP weighted NMHC802includes three specific TP weighted NMHC bars as follows: TP weighted NMHC bar804, TP weighted NMHC bar806, and TP weighted NMHC bar808. In these embodiments, each NMHC bar illustrates the FTP-75 bag results in g/mile of weighted NMHC for cold start phase402, stabilized phase404, and hot start phase406, respectively, obtained when measuring tailpipe NMHC emissions associated with TWC system1. In other embodiments, TWC system2TP weighted NMHC810includes three specific NMHC TP weighted bars as follows: TP weighted NMHC bar812, TP weighted NMHC bar814, and TP weighted NMHC bar816. In these embodiments, each NMHC bar illustrates the FTP-75 bag results in g/mile of weighted NMHC for cold start phase402, stabilized phase404, and hot start phase406, respectively, obtained when measuring tailpipe NMHC emissions associated with TWC system2.

In some embodiments, TP weighted NMHC emissions collected in g/mile during implementation of FTP-75 testing associated with TWC systems1and2are detailed in Table 6, below. In these embodiments, TWC system2includes an SPGM CC catalyst with ultra-low PGM loadings that exhibits slightly higher TP weighted NMHC values as compared to TWC system1that includes OEM CC and UF catalysts. In summary, the catalytic behavior exhibited by TWC system2during each one of the FTP-75 phases is comparable to the catalytic behavior of the high PGM based OEM catalyst.

TABLE 6TP weighted NMHC emission values associated withTWC systems 1 and 2, as illustrated in FIG. 7.TP WEIGHTEDTWCNMHCASSOCIATEDFTP-75 PHASESYSTEM[g/mile]ELEMENTCold start phase 40210.022804Stabilized phase 40410.002806Hot start phase 40610.002808Cold start phase 40220.035812Stabilized phase 40420.003814Hot start phase 40620.005816

FIG. 9is a graphical representation illustrating cumulative mid-tailpipe NOXemission results for TWC systems1and2(as described above), and employing a TGDI engine at given speeds, according to an embodiment. InFIG. 9, cumulative NOXvalues comparison900includes cumulative NOXcurve902, cumulative NOXcurve904, and FTP-75 protocol400. InFIG. 9, elements having substantially similar element numbers from previous figures function in a substantially similar manner.

In some embodiments, cumulative NOXcurve902illustrates cumulative NOXemission results obtained at mid-tailpipe (MID) associated with TWC system1at given speeds. In these embodiments, cumulative NOXcurve904illustrates cumulative NOXemission results obtained at MID associated with TWC system2at given speeds.

In some embodiments, the results are obtained during the implementation of Federal Test Procedure (FTP-75) protocol, FTP-75 protocol400as described inFIG. 4, for TWC systems1and2. In these embodiments, the results for each of the TWC systems are compared to assess improvements in conversion efficiency and performance of the TWC system including SPGM CC catalyst. Further to these embodiments, the synergistic effects of the aforementioned SPGM CC catalyst on NOXare verified. In these embodiments, verification of the synergistic effects are conducted by comparing the cumulative grams of NOX, for the TWC systems1and2, measured downstream at the mid-tailpipe section of the engine exhaust system including the TGDI engine, as previously described, above at given speeds.

In some embodiments, cumulative MID NOXvalues (cumulative NOXcurve904) associated with TWC system2are substantially lower than cumulative MID NOXvalues (cumulative NOXcurve902) associated with TWC system1. In these embodiments, the improvement in NOx mid-tailpipe emission (cumulative NOXcurve904) indicates SPGM CC catalyst exhibits greater functionality when compared to an OEM PGM CC catalyst. Further to these embodiments, the spinel oxide ZPGM layer within the SPGM CC catalyst increased functionality to the PGM layer, thereby lowering NOx mid-tailpipe emission values associated with TWC system2. In summary, the TWC system2exhibits higher NOXconversion efficiency than TWC system1.

FIG. 10is a graphical representation illustrating cumulative mid-tailpipe THC emission results for TWC systems1and2(as described above), and employing a TGDI engine at given speeds, according to an embodiment. InFIG. 10, cumulative THC values comparison1000includes cumulative THC curve1002, cumulative THC curve1004, and FTP-75 protocol400. InFIG. 10, elements having substantially similar element numbers from previous figures function in a substantially similar manner.

In some embodiments, cumulative THC curve1002illustrates cumulative THC emission results obtained at mid-tailpipe (MID) associated with TWC system1. In these embodiments, cumulative THC curve1004illustrates cumulative THC emission results obtained at MID associated with TWC system2.

In some embodiments, the results are obtained during the implementation of Federal Test Procedure (FTP-75) protocol, FTP-75 protocol400as described inFIG. 4, for TWC systems1and2. In these embodiments, the results for each of the TWC systems are compared to assess improvements in conversion efficiency and performance of the TWC system including ultra-low loading SPGM CC catalyst. Further to these embodiments, the synergistic effects of the aforementioned SPGM CC catalyst on THC are verified. In these embodiments, verification of the synergistic effects are conducted by comparing the cumulative grams of THC, for the TWC systems1and2, measured downstream at the mid-tailpipe section of the engine exhaust system including the TGDI engine, as previously described above, at given speeds.

In some embodiments, cumulative MID NOXvalues (cumulative NOXcurve1004) associated with TWC system2are slightly higher than cumulative MID NOXvalues (cumulative NOXcurve902) associated with TWC system1. In summary, the TWC system2exhibits slightly lower THC conversion efficiency that TWC system1.

Tailpipe Weighted Emission Bag Results from FTP-75 Test—PI Engine

FIG. 11is a graphical representation illustrating weighted NOX(g/mile) values at tailpipe for TWC systems3and4(as described above) employed within a naturally aspirated port injection (PI) engine using FTP-75 test protocol as described inFIG. 4, according to an embodiment. InFIG. 11, TP weighted NOXemission1100includes TWC system3TP weighted NOX1102and TWC system4TP weighted NOX1110.

In some embodiments, TWC system3TP weighted NOX1102includes three specific TP weighted NOXbars as follows: TP weighted NOx bar1104, TP weighted NOx bar1106, and TP weighted NOXbar1108. In these embodiments, each NOXbar illustrates the FTP-75 bag results in g/mile of weighted NOXfor cold start phase402, stabilized phase404, and hot start phase406, respectively, obtained when measuring tailpipe NOXweighted emissions associated with TWC system3. In other embodiments, TW system4TP weighted NOX1110includes three specific TP weighted NOXbars as follows: TP weighted NOXbar1112, TP weighted NOXbar1114, and TP weighted NOXbar1116. In these embodiments, each NOXbar illustrates the FTP-75 bag results in g/mile of weighted NOXfor cold start phase402, stabilized phase404, and hot start phase406, respectively, obtained when measuring tailpipe NOXemissions associated with TWC system4.

In some embodiments, TP weighted NOXemissions collected in g/mile during implementation of FTP-75 testing associated with TWC systems3and4are detailed in Table 7, below. In these embodiments, TWC system4includes SPGM CC and PGM-based UF catalysts that exhibits higher NOXconversion as compared to TWC system3that includes OEM CC and UF catalysts. Further to these embodiments and at the end of cold start phase402, TWC system4exhibits slightly higher TP weighted NOXvalues than TWC system3. Still further to these embodiments and after stabilized phase404and hot start phase406, TWC system4exhibits lower TP weighted NOXvalues than TWC system3. These results confirm that employing an SPGM CC catalyst incorporating Ni—Fe binary spinel to low loading PGM total 10 g/ft3is effective CC catalyst. In summary, TWC system4exhibits improved performance in NOXreduction when compared with TWC system3.

TABLE 7TP weighted NOxemission values associatedwith TWC systems 3 and 4, as illustrated in FIG. 11.TWCTP WEIGHTED NOxASSOCIATEDFTP-75 PHASESYSTEM[g/mile]ELEMENTCold start phase 40230.0131104Stabilized phase 40430.0061106Hot start phase 40630.0021108Cold start phase 40240.0151112Stabilized phase 40440.0031114Hot start phase 40640.0011116

While various aspects and embodiments have been disclosed, other aspects and embodiments may be contemplated. The various aspects and embodiments disclosed here are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.