Three-way catalyst with reduced palladium loading and method of making a three-way catalyst

Abstract

A three-way catalyst with reduced palladium loading is provided. The catalyst includes an inert substrate and a palladium catalyst material coated on the substrate. The palladium catalyst material includes a support material formed from one of: 10% CeO2 / Al2O3, 20% CeO2-Al2O3 (20CeAlOy), 30% CeO2-Al2O3 (30CeAlOy), Al2O3, and M Ox-Al2O3, wherein M is one of copper, iron, manganese, titanium, zirconium, magnesium, strontium, and barium. The palladium catalyst material includes a layer of CeO2 material disposed on the support material, wherein the layer of CeO2 material is dispersed on a surface of the support material. The palladium catalyst material includes an active component including a layer of praseodymium oxide particles dispersed throughout the surface of the layer of CeO2 material and a layer of palladium particles disposed on the surface of the layer of CeO2 material at locations each corresponding to a respective location of each praseodymium particle and dispersed throughout the surface of the layer of CeO2 material.

Description

[0001] Government Contract

[0002] This application was filed with government support under contract number DE-EE0009196 awarded by the Department of Energy. The government holds certain rights in this disclosure.

[0003] introduction. Technical Field

[0004] This disclosure generally relates to a ternary catalyst with reduced palladium loading and a method for preparing the ternary catalyst. Background Technology

[0005] Exhaust aftertreatment systems are used to treat exhaust gases, such as those generated by the operation of an internal combustion engine. Exhaust gases can be defined as untreated exhaust gases, including combustion byproducts containing hydrocarbon fuels and oxygen, emitted from an internal combustion engine. These byproducts may include hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx). x Exhaust gas aftertreatment systems may include catalytic converter units comprising three-way catalysts. A three-way catalyst is a device or structure within a catalytic converter unit that provides one or more surfaces treated with a coating containing at least one catalyst. A catalyst is a material that promotes the rapid reaction of components of an untreated exhaust gas stream into components of a treated exhaust gas stream. Specifically, a catalyst is a material that increases the rate of a chemical reaction without undergoing any permanent changes itself. In one example, a three-way catalyst can promote the reaction of NO in an untreated exhaust gas stream. x HC and CO react rapidly to form nitrogen (N2), water, and carbon dioxide (CO2) in the treated waste gas stream. A three-way catalyst can be defined as one that oxidizes HC and CO and reduces NO. x The device produces a treated waste gas stream containing water, N2, and CO2. Summary of the Invention

[0006] A three-way catalyst for reducing palladium loading is provided. The three-way catalyst includes an inert substrate and a palladium catalyst material coated with the inert substrate. The palladium catalyst material includes a support material formed from materials selected from the group consisting of: 10% CeO2 / Al2O3, 20% CeO2-Al2O3 (20CeAlOy), 30% CeO2-Al2O3 (30CeAlOy), Al2O3, and... M Ox-Al2O3, where MIt is a metal including at least one selected from copper, iron, manganese, titanium, zirconium, magnesium, strontium, and barium. The palladium catalyst material also includes a CeO2 material layer disposed on a support material and having a surface, wherein the CeO2 material layer is dispersed on the surface of the support material. The palladium catalyst material also includes an active component. The active component includes a first layer of praseodymium oxide particles disposed on and dispersed throughout the surface of the CeO2 material layer, and a second layer of multiple palladium particles disposed at multiple locations on and dispersed throughout the surface of the CeO2 material layer, each of the multiple locations corresponding to a corresponding location of each of the multiple praseodymium particles.

[0007] In some embodiments, the CeO2 material layer is a CeO2 base layer. The surface of the CeO2 material layer is a first surface. The CeO2 base layer includes a plurality of CeO2 nanostructures protruding upward from the first surface, and each nanostructure has a second surface. A first layer of praseodymium particles is disposed on and dispersed throughout the second surface of each of the plurality of CeO2 nanostructures. A second layer of palladium particles is disposed on and dispersed throughout the second surface of each of the plurality of CeO2 nanostructures.

[0008] In some embodiments, the carrier material is 10% CeO2 / Al2O3 (10CA), which is formed by impregnating Ce nitrate onto Al2O3 and then calcining it at a temperature of 500°C to 1050°C for 1 to 5 hours.

[0009] In some embodiments, the carrier material is 10% CeO2 / Al2O3 (10CA), which is produced by impregnating Ce nitrate onto Al2O3 and then calcining it at 950°C for two hours.

[0010] In some embodiments, the carrier material is 10% CeO2 / Al2O3 (10CeAlO y This is achieved by impregnating Ce nitrate into Al(OH)₂. x It is produced by calcining at 550°C for two hours.

[0011] In some embodiments, the carrier material is 30CeAlO y .

[0012] In some embodiments, the carrier material is calcined at a temperature of 500°C to 1050°C for two hours.

[0013] In some embodiments, the carrier material is calcined at 950°C for 2 hours using 30CeAlO3. y .

[0014] In some embodiments, the carrier material is M O x -Al2O3.

[0015] In some embodiments, the support material is calcined at a temperature of 550 °C for two hours.

[0016] In some embodiments, the active component is z Pd-δCe n Pr 1-n O x where z is 0.1 to 1.5, δ is 5.0 to 40, and n is 0.70 to 0.95.

[0017] In some embodiments, the active component is selected from the group consisting of 0.8Pd-20Ce 0.90 Pr 0.10 O x and 0.8Pd-30Ce 0.90 Pr 0.10 O x .

[0018] In some embodiments, the second layer of multiple palladium particles is formed from palladium monomers.

[0019] According to one alternative embodiment, an apparatus is provided. The apparatus includes an internal combustion engine configured to produce an untreated exhaust gas stream and a catalytic converter including a three-way catalyst. The three-way catalyst facilitates chemical reactions to convert the untreated exhaust gas stream into a treated exhaust gas stream. The three-way catalyst includes an inert substrate and a palladium catalyst material coating the inert substrate. The palladium catalyst material includes a support material that is a material selected from the group consisting of 10% Ce02 / A1203, 20% Ce02-A1203 (20CeA10y), 30% Ce02-A1203 (30CeA10y), A1203, and M O x -A1203, where M is a metal and includes at least one of copper, iron, manganese, titanium, zirconium, magnesium, strontium, and barium. The palladium catalyst material further includes a layer of Ce02material disposed on the support material and having a surface, and an active component, where the layer of Ce02material is dispersed on the surface of the support material. The active component includes a first layer of praseodymium oxide particles disposed on and dispersed throughout the surface of the layer of Ce02material, and a second layer of multiple palladium particles disposed on and dispersed throughout the surface of the layer of Ce02material at multiple locations each corresponding to a respective location of each of the multiple praseodymium particles.

[0020] In some embodiments, the active component is z Pd-δCe n Pr 1-n O xwhere z is 0.1 to 1.5, δ is 5.0 to 40, and n is 0.70 to 0.95.

[0021] In some embodiments, the active component is 0.8Pd-20Ce 0.90 Pr 0.10 O x .

[0022] In some embodiments, the active component is 0.8Pd-30Ce 0.90 Pr 0.10 O x .

[0023] In some embodiments, the second plurality of palladium particles is formed from palladium monomers.

[0024] A method of making a three-way catalyst is provided. The method includes producing a palladium catalyst material. Producing the palladium catalyst includes selecting a support material in powder form, the support material formed from a material selected from the group including 10% Ce02 / A1203, 20% Ce02-A1203 (20CeA10y), 30% Ce02-A1203 (30CeA10y), A1203, and y ), A1203, and M O x -A1203, where M is a metal and includes at least one of copper, iron, manganese, titanium, zirconium, magnesium, strontium, and barium. Producing the palladium catalyst further includes providing a Ce-containing material layer on a surface of the support material to form a workpiece, and calcining the workpiece. Producing the palladium catalyst further includes providing a Ce02layer on the support surface and the Ce-containing material layer to form a precursor, the Ce02layer having a first surface, and calcining the precursor to form a calcined precursor. Producing the palladium catalyst further includes disposing a liquid co-impregnation composition on the calcined precursor to form a product, where the liquid co-impregnation composition includes Ce02, praseodymium, and palladium, and calcining the product to produce a plurality of Ce02structures projecting upward from the first surface and an active component on the product. Each of the plurality of Ce02structures has a second surface. The active component includes a first layer of praseodymium particles disposed on and dispersed throughout the second surface of each of the plurality of Ce02nanostructures and a second plurality of palladium particles disposed on and dispersed throughout the second surface of each of the plurality of Ce02nanostructures at a plurality of locations each corresponding to a respective location of each of the plurality of praseodymium particles. The method further includes producing a slurry with the palladium catalyst material, coating an inert substrate of the three-way catalyst with the slurry, and drying the slurry on the inert substrate.

[0025] In some embodiments, the active component is z Pd-δCe n Pr 1-n O xwhere z is 0.1 to 1.5, δ is 5.0 to 40, and n is 0.70 to 0.95.

[0026] The present invention provides the following technical solutions:

[0027] 1. A reduced palladium load three-way catalyst, the three-way catalyst comprising:

[0028] an inert substrate; and

[0029] a palladium catalyst material coated on the inert substrate, the palladium catalyst material comprising:

[0030] a support material formed from a material selected from the group comprising: 10% Ce02 / A1203, 20% Ce02-A1203 (20CeAIOy), 30% Ce02-A1203 (30CeAIOy), A1203, and M Ox-A1203, where M is a metal comprising at least one of copper, iron, manganese, titanium, zirconium, magnesium, strontium, and barium;

[0031] a layer of Ce02material disposed on the support material and having a surface, wherein the layer of Ce02material is dispersed on the surface of the support material; and

[0032] an active component comprising:

[0033] a first layer of praseodymium oxide particles disposed on and dispersed across the surface of the layer of Ce02material; and

[0034] a second layer of a plurality of palladium particles disposed on and dispersed across the surface of the layer of Ce02material at a plurality of locations, the plurality of locations each corresponding to a respective location of each of the plurality of praseodymium particles.

[0035] The three-way catalyst of technical solution 1, wherein the layer of Ce02material is a Ce02-based layer;

[0036] wherein the surface of the layer of Ce02material is a first surface;

[0037] wherein the Ce02-based layer includes a plurality of Ce02nanostructures protruding upward from the first surface, and each nanostructure has a second surface;

[0038] wherein the first layer of praseodymium particles is disposed on and dispersed across the second surface of each of the plurality of Ce02nanostructures; and

[0039] wherein the second layer of a plurality of palladium particles is disposed on and dispersed across the second surface of each of the plurality of Ce02nanostructures.

[0040] The three-way catalyst according to technical solution 1, wherein the support material is 10% CeO2 / Al2O3 (10CA) formed by impregnating Ce nitrate onto Al2O3 and subsequently calcining at a temperature of 500°C to 1050°C for 1 hour to 5 hours.

[0041] The three-way catalyst according to technical solution 1, wherein the support material is 10% CeO2 / Al2O3 (10CA) formed by impregnating Ce nitrate onto Al2O3 and subsequently calcining at a temperature of 950°C for two hours.

[0042] The three-way catalyst according to technical solution 1, wherein the support material is 10% CeO2 / Al2O3 (10CeAlOy) formed by impregnating Ce nitrate onto Al(OH) x and subsequently calcining at a temperature of 550°C for 2 hours.

[0043] The three-way catalyst according to technical solution 1, wherein the support material is 30CeAlO y .

[0044] The three-way catalyst according to technical solution 6, wherein the support material is calcined at a temperature of 500°C to 1050°C for two hours.

[0045] The three-way catalyst according to technical solution 1, wherein the support material is 30CeAlO y .

[0046] The three-way catalyst according to technical solution 1, wherein the support material is M O x -Al2O3.

[0047] The three-way catalyst according to technical solution 9, wherein the support material is calcined at a temperature of 550°C for two hours.

[0048] The three-way catalyst according to technical solution 1, wherein the active component is z Pd-δCe n Pr 1-n O x , wherein z is 0.1 to 1.5, δ is 5.0 to 40, and n is 0.70 to 0.95.

[0049] The three-way catalyst according to technical solution 1, wherein the active component is selected from the group comprising 0.8Pd-20Ce 0.90 Pr 0.10 Ox and 0.8 Pd-30 Ce 0.90 Pr 0.10 O x .

[0050] The three-way catalyst of claim 1, wherein the second plurality of palladium particles are formed of palladium single atoms.

[0051] An apparatus comprising:

[0052] an internal combustion engine configured to produce an untreated exhaust stream; and

[0053] a catalytic converter comprising a three-way catalyst, wherein the three-way catalyst facilitates a chemical reaction to convert the untreated exhaust stream into a treated exhaust stream, the three-way catalyst comprising:

[0054] an inert substrate; and

[0055] a palladium catalyst material coating the inert substrate, the palladium catalyst material comprising:

[0056] a support material formed of a material selected from the group comprising: 10% Ce02 / A1203, 20% Ce02-A1203 (20CeA10y), 30% Ce02-A1203 (30CeA10y), A1203, and M Ox-A1203, wherein M is a metal and comprises at least one of copper, iron, manganese, titanium, zirconium, magnesium, strontium, and barium;

[0057] a layer of Ce02material disposed on the support material and having a surface, wherein the layer of Ce02material is dispersed on the surface of the support material; and

[0058] an active component comprising:

[0059] a first layer of praseodymium oxide particles disposed on and dispersed across the surface of the layer of Ce02material; and

[0060] a second plurality of palladium particles disposed on and dispersed across the surface of the layer of Ce02material at a plurality of locations, each of the plurality of locations corresponding to a respective location of each of the plurality of praseodymium particles.

[0061] The apparatus of claim 14, wherein the active component is z Pd-5Ce n Pr 1-n O x wherein z is 0.1 to 1.5, δ is 5.0 to 40, and n is 0.70 to 0.95.

[0062] The device of claim 14, wherein the active component is 0.8Pd-20Ce 0.90 Pr 0.10 O x .

[0063] The device of claim 14, wherein the active component is 0.8Pd-30Ce 0.90 Pr 0.10 O x .

[0064] The device of claim 14, wherein the second plurality of palladium particles are formed from palladium single atoms.

[0065] A method of manufacturing a three-way catalyst, the method comprising:

[0066] Producing a palladium catalyst material, comprising:

[0067] Selecting a support material in powder form, the support material formed from a material selected from the group comprising: 10% Ce02 / A1203, 20% Ce02-A1203 (20CeA10y), 30% Ce02-A1203 (30CeA10y), A1203, and M Ox-A1203, wherein M is a metal and comprises at least one of copper, iron, manganese, titanium, zirconium, magnesium, strontium, and barium;

[0068] Providing a Ce-containing material layer on a surface of the support material to form a workpiece;

[0069] Calcining the workpiece;

[0070] Providing a Ce02layer on the support surface and Ce-containing material layer to form a precursor, the Ce02layer having a first surface;

[0071] Calcining the precursor to form a calcined precursor;

[0072] Providing a liquid co-impregnation composition on the calcined precursor to form a product, wherein the liquid co-impregnation composition comprises Ce02, praseodymium, and palladium;

[0073] Calcining the product to produce a plurality of Ce02structures projecting upward from the first surface and an active component on the product, wherein each of the plurality of Ce02structures has a second surface, the active component comprising:

[0074] a first layer of praseodymium particles disposed on and dispersed throughout the second surface of each of the plurality of Ce02nanostructures; and

[0075] a second plurality of palladium particles disposed on a second surface of each of the plurality of Ce02nanostructures at a plurality of locations and dispersed throughout the second surface, the plurality of locations each corresponding to a respective location of each of the plurality of praseodymium particles;

[0076] producing a slurry with a palladium catalyst material;

[0077] coating an inert substrate of the three-way catalyst with the slurry; and

[0078] drying the slurry on the inert substrate.

[0079] The method of claim 19, wherein the active component is zPd-5Ce n Pr 1-n O x wherein z is 0.1 to 1.5, 5 is 5.0 to 40, and n is 0.70 to 0.95.

[0080] The foregoing features and advantages of the present disclosure, as well as other features and advantages of the present disclosure, will become more apparent from the following detailed description of the best mode contemplated of carrying out the present disclosure, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0081] Figure 1 schematically illustrates an exemplary catalytic converter device according to the present disclosure, the device including a three-way catalyst configured to provide exhaust gas aftertreatment to an untreated exhaust stream;

[0082] Figure 2 schematically illustrates a cross-sectional perspective view of one embodiment of a catalytic converter device according to the present disclosure of Figure 1

[0083] Figure 3 schematically illustrates a device according to the present disclosure including a catalytic converter configured for providing exhaust gas aftertreatment to an exhaust stream produced by an internal combustion engine;

[0084] Figures 4-6 schematically illustrates an exemplary manufacturing sequence for forming a three-way catalyst according to the present disclosure; Figure 1

[0085] Figure 4 schematically illustrates a first operation, which can be described as an initial wet impregnation (IWI) operation;

[0086] Figure 5 schematically illustrates a second operation, which can be described as a second initial wet impregnation operation;

[0087] Figure 6 ​​A third operation is schematically shown, in which calcination is performed, resulting in evaporation of the residue of the liquid co-impregnation composition Figure 5

[0088] Figure 7 A schematic representation of an alternative embodiment of a three-way catalyst according to the present disclosure is shown, which comprises a layer of Ce02material homogeneously dispersed on the surface of a support material; Figure 1

[0089] Figure 8 is a graph showing infrared spectroscopy analysis of various three-way catalysts according to the present disclosure comprising different concentrations of palladium deposited on the three-way catalyst; and

[0090] Figure 9 is a graph showing palladium particle deactivation on a first three-way catalyst comprising baseline palladium dispersion and on a second three-way catalyst comprising palladium dispersion according to the disclosed method, according to the present disclosure. DETAILED DESCRIPTION

[0091] An exhaust aftertreatment system receives an untreated exhaust stream from a device or system, such as an internal combustion engine. The temperature of the untreated exhaust stream can vary based on factors such as output torque provided by the device or system and ambient temperature. Catalysts within a catalytic converter device can be sensitive to high temperatures. At high temperatures, the catalysts can consume, deactivate, or reduce their effectiveness due to sintering.

[0092] A three-way catalyst can include a catalytic monolith structure or a honeycomb catalytic powder block structure within the three-way catalyst. The catalytic monolith structure includes a plurality of pores that define flow paths through the catalytic monolith structure. Within the flow paths, a large surface of the catalytic monolith structure is coated or covered with catalyst particles or catalyst material. This coating can be applied as a washcoat, which can be described as a liquid or slurry material including solid particles used to deposit the solid particles on a surface, if it is a monolith or support structure. The untreated exhaust stream is directed through the flow paths. Within the flow paths, chemical components of the untreated exhaust stream, such as carbon monoxide, hydrocarbons, and NOx x ) contact the catalyst material and are converted into compounds, such as carbon dioxide, water, and nitrogen gas, through chemical reactions. After these chemical reactions occur, the untreated exhaust stream becomes a treated exhaust stream. Palladium (Pd) is a catalyst that can be used as a catalyst material within the three-way catalyst.

[0093] ​​Pd is rare and expensive. It is beneficial to reduce the amount of Pd used in a three-way catalyst and to reduce the frequency at which a three-way catalyst must be replaced (collectively referred to as reduced Pd loading). A three-way catalyst having a reduced Pd loading and a method of making the same is provided. The three-way catalyst can include an inert substrate, for example, which results in a honeycomb brick material, and the inert substrate can be coated with a Pd catalyst material.

[0094] The Pd catalyst material can initially be formed as a powder, which is then used to create a slurry or washcoat to coat the inert substrate of the three-way catalyst. The powder can include a stabilized support material in powder form, which can include a CeO2, Pr6O 11 The defects on the surface of the powder are beneficial to create sites on the surface that attract Pd particles and act as a binder for them. The support material can be described as an inert material on which active components can be deposited. The stabilized support material can be selected or enhanced to achieve superior hydrophilic properties on the surface of the support material. On the support material, Pd particles or Pd monomers can be widely dispersed or widely uniformly distributed as the primary active component. In one embodiment, the nano-sized Pd-CePrO x The active component (Pd exists as dispersed monomers or has small dispersed Pd clusters in fresh catalyst state) can be used on an Al2O3 support with superior or enhanced hydrophilic properties. As a result, the Pd catalyst material includes a stabilized support material with Pd particles widely or up to 100% dispersed on the surface of the stabilized support material. In one exemplary embodiment, the stabilized support structure includes an Al2O3 support with a layer of Ce-based material coating the Al2O3 support such that the Pd particles dispersed on the surface are separated from the Al2O3 support by the layer of Ce material. The Pd catalyst material can be provided on the surface of a catalytic monolithic structure, for example, where the powder is used to create a slurry that is wash-coated on the surface of the catalytic monolithic structure. The resulting three-way catalyst structure coated with the disclosed Pd catalyst material shows superior aging resistance and performance or activity matching a baseline three-way catalyst equipped with Pd / Al2O3 while using only 40% of the Pd used by the baseline three-way catalyst. The Pd nano-clusters or monomer Pd widely dispersed on the Pr-modified Pd / Al2O3 mixed oxide can mitigate or balance the deactivation of Pd on the three-way catalyst.

[0095] The Pd catalyst material exhibits a layered structure in which the support material is covered by small CeO2 particles. These CeO2 particles exhibit a high defect density due to praseodymium (Pr) doping. This stabilized support material including a high defect density enables the Pd monomers to be widely dispersed during a wet impregnation process and can avoid sintering under various operating conditions.

[0096] Pd catalyst materials can include a layered support structure comprising Ce-containing particles or CeO2 particles on the outer surface. During surface formation, the Ce-containing particles crystallize. The surface of the crystals formed with the Ce material can be smooth and defect-free. Pd particles are attracted to the surface and form bonds with defects on the surface, and if the surface has too few defects, not enough Pd particles can adhere to the surface for the catalyst to be effective. By increasing the number or occurrence rate of defects on the Ce material surface, Pd particles can be attracted and widely dispersed on the surface of the layered support structure.

[0097] Pd catalyst materials can include high or selected defect densities due to calibrated Pr doping or the formation of surfaces comprising widely dispersed Pr particles. This defect density can be further increased by incorporating three-dimensional CeO2 nanostructures projecting upwards from the material surface, increasing the total surface area, and / or by reducing the Ce crystal size to increase the boundary density between adjacent Ce crystals. The resulting selected defect density can be used to control and produce excellent Pd single-atom dispersion on ternary catalysts. This excellent Pd dispersion results in superior anti-aging properties of Pd on ternary catalysts.

[0098] A method for producing Pd catalyst materials for three-way catalysts can be described as co-impregnation of Pd, Pr, and Ce materials onto a support structure. This method may also include utilizing a selected palladium / cerium (Pd / Ce) ratio and a selected praseodymium / cerium (Pr / Ce) ratio.

[0099] Various support materials can be used to form Pd catalyst materials to provide excellent hydrophilic properties. A first embodiment of the support material may include 10CA, which can be described as 10% CeO2 / Al2O3 (10% CeO2 / Al2O3, derived from Ce nitrate impregnation onto Al2O3, calcined at 950°C for 2 hours). A second embodiment of the support material may include 10CeAlO y It can be described as 10% CeO2 / Al2O3 (10% CeO2 / Al2O3, derived from Ce nitrate impregnation into Al(OH)). x (The mixture is calcined at 550°C for 2 hours). A third embodiment of the carrier material may include 30% alloy, which can be described as 30% CeO2-Al2O3. A fourth embodiment of the carrier material may include 30% CeAlO2-Al2O3. y -950, which can be described as 30% CeO2-Al2O3 calcined at 950°C for 2 hours. A fifth embodiment of the support material may include Al2O3-HD, which can be described as Al2O3 with high density. A sixth embodiment of the support material may include... M O x -Al2O3, which can be described as a commercially viable mixed oxide material orM The salt is impregnated onto the AI2O3, followed by calcination at 550 °C for 2 hours. M The metal can be copper, iron, manganese, titanium, zirconium, magnesium, strontium, barium, and the like. The AI2O3 support material 110 can include any of these support materials.

[0100] A three-way catalyst for reduced palladium loading is provided. The three-way catalyst includes an inert substrate and a palladium catalyst material coated on the inert substrate. The palladium catalyst material includes a support material formed from a material selected from a group including 10% CeO2 / AI2O3, 20% CeO2-AI2O3 (20CeAI OY), 30% CeO2-AI2O3 (30CeAI OY), AI2O3, and M Ox-AI2O3, wherein M The metal can be copper, iron, manganese, titanium, zirconium, magnesium, strontium, barium, and the like. The palladium catalyst material further includes a layer of CeO2 material disposed on or formed on and having a surface on the support material, wherein the layer of CeO2 material is dispersed on the surface of the support material. The palladium catalyst material further includes an active component including a first layer of praseodymium oxide particles disposed on and dispersed across the surface of the layer of CeO2 material and a second layer of a plurality of palladium particles disposed on and dispersed across the surface of the layer of CeO2 material at a plurality of locations each corresponding to a respective location of each of the plurality of praseodymium particles.

[0101] The layer of CeO2 material can be a CeO2-based layer. The surface of the layer of CeO2 material can be a first surface. The CeO2-based layer can include a plurality of CeO2 nanostructures protruding upward from the first surface, and each nanostructure has a second surface. The first layer of praseodymium particles can be disposed on and dispersed across the second surface of each of the plurality of CeO2 nanostructures. The second layer of a plurality of palladium particles is disposed on and dispersed across the second surface of each of the plurality of CeO2 nanostructures.

[0102] The support material can be 10% CeO2 / AI2O3 (10CA) formed by impregnating a Ce nitrate salt onto AI2O3 and subsequently calcining at a temperature of 500 °C to 1050 °C for 1 hour to 5 hours.

[0103] The support material can be 10% CeO2 / AI2O3 (10CA) formed by impregnating a Ce nitrate salt onto AI2O3 and subsequently calcining at a temperature of 950 °C for two hours.

[0104] The support material can be 10% CeO2 / AI2O3 (10CeAI OY) formed by impregnating a Ce nitrate salt onto AI(OH)x The support material can be 30CeAlOy calcined at a temperature of 550 °C for 2 hours.

[0105] The support material can be 30CeAlOy y .

[0106] The support material can be calcined at a temperature of 500 °C to 1050 °C for 2 hours.

[0107] The support material can be 30CeAlOy calcined at a temperature of 950 °C for 2 hours. y .

[0108] The support material can be M O x -Al2O3.

[0109] The support material can be calcined at a temperature of 550 °C for 2 hours.

[0110] The active component can be z Pd-5Ce n Pr 1-n O x where z is 0.1 to 1.5, δ is 5 to 40, and n is 0.70 to 0.95, in particular, z can be expressed as parts by weight based on 100 parts by weight of Pd loading of the active component, δ can be expressed as parts by weight based on 100 parts by weight of the active component, and n can be expressed as a molar ratio.

[0111] The active component can be selected from the group comprising 0.8Pd-20Ce 0.90 Pr 0.10 O x and 0.8Pd-30Ce 0.90 Pr 0.10 O x .

[0112] The second plurality of palladium particles can be formed from palladium monomers.

[0113] An apparatus is provided. The apparatus can include a vehicle. The apparatus includes an internal combustion engine configured to produce an untreated exhaust stream and a catalytic converter including a three-way catalyst. The three-way catalyst facilitates chemical reactions to convert the untreated exhaust stream into a treated exhaust stream. The three-way catalyst includes an inert substrate and a palladium catalyst material coated on the inert substrate. The palladium catalyst material includes a support material formed from a material selected from the group comprising 10% CeO2 / Al2O3, 20% CeO2-Al2O3 (20CeAlOy), 30% CeO2-Al2O3 (30CeAlOy), Al2O3, and M O x- AI2O3, wherein M is a metal and includes at least one of copper, iron, manganese, titanium, zirconium, magnesium, strontium, and barium. The palladium catalyst material further includes a layer of CeO2 material disposed on the support material and having a surface, wherein the layer of CeO2 material is dispersed on the surface of the support material. The palladium catalyst material further includes an active component. The active component includes a first layer of praseodymium oxide particles disposed on and dispersed across the surface of the layer of CeO2 material, and a second layer of a plurality of palladium particles disposed on and dispersed across the surface of the layer of CeO2 material at a plurality of locations, each of the plurality of locations corresponding to a respective location of each of the plurality of praseodymium particles.

[0114] The active component can be z Pd-5Ce n Pr 1-n O x wherein z is 0.1 to 1.5, δ is 5 to 40, and n is 0.70 to 0.95.

[0115] The active component can be 0.8Pd-20Ce 0.90 Pr 0.10 O x .

[0116] The active component can be 0.8Pd-30Ce 0.90 Pr 0.10 O x .

[0117] The second layer of a plurality of palladium particles can be formed of palladium monatomic atoms.

[0118] Reference now will be made to the drawings wherein like numerals refer to like components throughout the several figures, Figure 1 An exemplary catalytic converter device 10 is schematically illustrated that includes a three-way catalyst 20 that provides exhaust gas aftertreatment to an untreated exhaust stream 32. The three-way catalyst 20 includes the disclosed Pd catalyst material that includes Pd monatomic dispersion. The catalytic converter device 10 includes an inlet 30 and an outlet 40. Each of the inlet 30 and the outlet 40 is connected to an exhaust gas aftertreatment system component, such as a pipe configured to move exhaust gas from one device to a second device. The untreated exhaust stream 32 is shown entering the inlet 30. The treated exhaust stream 42 is shown exiting the outlet 40.

[0119] Figure 2 An exemplary catalytic converter device 10 is schematically illustrated that includes a three-way catalyst 20 that provides exhaust gas aftertreatment to an untreated exhaust stream 32. The three-way catalyst 20 includes the disclosed Pd catalyst material that includes Pd monatomic dispersion. The catalytic converter device 10 includes an inlet 30 and an outlet 40. Each of the inlet 30 and the outlet 40 is connected to an exhaust gas aftertreatment system component, such as a pipe configured to move exhaust gas from one device to a second device. The untreated exhaust stream 32 is shown entering the inlet 30. The treated exhaust stream 42 is shown exiting the outlet 40. Figure 1A cross-sectional perspective view of one embodiment of a catalytic converter device 10. The catalytic converter device 10 includes a three-way catalyst 20 embodied as two catalytic monoliths 22. Each catalytic monolith 22 can include a plurality of cells that define flow paths through the catalytic monolith 22. The surface of the catalytic monolith 22, including the surface of the flow paths inside the catalytic monolith 22, can be coated with the disclosed Pd catalyst material. Each catalytic monolith 22 can include an annular gasket 24 around the catalytic monolith 22. The catalytic converter device 10 is also shown to include a first layer 14 of a metallic heat shield and a second layer 12 of a metallic heat shield. The catalytic converter device 10 is also shown to include an inlet 30 and an outlet 40.

[0120] Figure 3 A device 800 is schematically shown that includes an internal combustion engine 820 and a catalytic converter device 10. The device 800 is embodied as a vehicle. The engine 820 is connected to the three-way catalyst 20 by a pipe or conduit configured to transport high temperature exhaust gas Figure 2 . An untreated exhaust gas stream 32 is shown entering the catalytic converter device 10. As a result of the operation of the three-way catalyst 20 disclosed herein within the catalytic converter device 10, a treated exhaust gas stream 42 is shown exiting the catalytic converter device 10. The pipe or conduit exiting the catalytic converter device 10 can be connected to other exhaust aftertreatment devices or structures, such as muffler devices and tailpipes.

[0121] Figure 4 and Figure 5 A manufacturing operation sequence is shown to produce a Pd catalyst material for coating Figure 1 a three-way catalyst 20; Figure 4 An operation 100 is schematically shown that can be described as an initial wet impregnation (IWI) operation in which an AI2O3 support material 110 is provided. The AI2O3 support material 110 can be in powder form, and Figures 4-7The planar appearance of the AI2O3 support material 110 in FIG. 1 can be simplified for illustrative purposes and / or as a result of significant magnification of the AI2O3 support material 110. The AI2O3 support material 110 includes a surface 112. A dispensing nozzle 120 is provided, including a supply of a Ce-containing solution 130. In one exemplary embodiment, the Ce-containing solution can include a 10 wt% Ce(N03)3solution. A droplet 132 of the Ce-containing solution is shown deposited on the surface 112 of the AI2O3 support material 110. Multiple droplets 132 are deposited on the surface 112 until a selected amount of the Ce-containing solution is deposited on the surface 112. Once the selected amount of the Ce-containing solution is deposited on the surface 112, a heat calcination process is applied to the AI2O3 support material 110. In one embodiment, the calcination process is performed at 950 °C. In another embodiment, the calcination process is performed at a temperature in the range of 500 °C to 1050 °C. The calcination process, particularly within the relatively higher portion of the defined range (such as at 950 °C or at least exceeding the Ce melting point of 795 °C), can be particularly beneficial in that the Ce within the provided solution can melt into a liquid state and can distribute throughout and coat a majority or all of the AI2O3 support material 110 before the Ce subsequently cools and solidifies. As a result of the operation 100, the solvent of the Ce-containing solution is evaporated and a layer of Ce-containing compounds on the surface 112 is dried.

[0122] Figure 5 The operation 200 is schematically shown, which can be described as a co- impregnation process. As a result of the operation 100, Figure 2 The AI2O3 support material 110 is shown including a layer of dried Ce- containing compounds 240 on the surface 112 as a result of the operation 100. The Ce- containing compounds 240 can cover a majority of the surface 112, or can cover the entire surface 112. In the operation 200, a liquid co-impregnation composition 205 is applied to the AI2O3 support material 110 and the Ce-containing compounds 240. In one embodiment, the liquid co-impregnation composition 205 can include Pd(N03)2, Pd(N03)3, and a Ce-containing liquid. The Ce-containing liquid can include colloidal Ce02or cerium nitrate (Ce(N03)3). The operation 200 can include calcination at a relatively lower temperature than compared to the operation 100, for example including calcination at 500 °C, resulting in evaporation of the liquid components of the liquid co-impregnation composition 205. Figure 5

[0123] ​As a result of the co-impregnation process and subsequent calcination of operation 200, additional newly-deposited Ce-containing material is deposited on the Ce-containing compound 240 in the form of multiple Ce crystals. Where the liquid co-impregnation composition 205 includes cerium nitrate, the resulting surface of the deposited Ce-containing material can be relatively flat or can conform to the shape of the AI2O3 support material 110 beneath the deposited Ce material. Where the liquid co-impregnation composition 205 includes colloidal CeO2, the resulting surface of the deposited Ce-containing material can include three-dimensional features that can be described as CeO2nanostructures protruding upward from the surface. In addition, Pr particles are dispersed throughout the newly-deposited Ce-containing material. Boundaries between the Ce crystals of the newly-deposited Ce-containing material can attract and form chemical bonds with Pd particles. Additionally, the Pr particles dispersed in the newly-deposited Ce-containing material can create defects in the surface of the Ce-containing material and can attract and form chemical bonds with Pd particles. By controlling the Ce crystal size and by controlling how much Pr is dispersed in the deposited Ce-containing material, how widely and efficiently Pd particles can be dispersed throughout the surface of the deposited Ce-containing material can be controlled. In one embodiment, enough defects are created in the surface of the deposited Ce-containing material that monatomic Pd particles can be dispersed throughout the surface of the resulting Pd catalyst material.

[0124] Figure 6 An embodiment of a Pd catalyst material 500 is schematically illustrated that is formed as a result of operation 200, where the surface of the Pd catalyst material 500 includes CeO2nanostructures 450. The AI2O3 support material 110 is illustrated as including a Ce material 440 that coats the surface 112. The CeO2nanostructures 450 are illustrated as formed on the Ce material 440, consistent with operation 200 of Figure 5 Figure 5 Figure 6

[0125] Figure 7 An alternative embodiment of a Pd catalyst material 900 is schematically illustrated that includes a layer 940 of CeO2material that is uniformly dispersed on the surface 112 of the support material 110. The support material 110 is illustrated as including the layer 940 formed on the surface 112. The layer 940 can include a relatively flat surface 942, consistent with operation 200 of Figure 5 ​​​The operation is consistent with 200, which utilizes a liquid co-impregnation composition 205 comprising cerium nitrate. Surface 942 includes deposited and disposed Pr particles on surface 942. A plurality of Pd particles 560 are shown disposed on surface 942 at positions corresponding to the Pr particles disposed on surface 942. Figure 7 It is provided for illustrative purposes and may not be drawn to scale because Pd particles 560 can be single Pd atoms.

[0126] The active component coating, including Pd, can be dispersed in [a specific environment] after a drying or calcination process. Figure 4 The coating is applied to the Al2O3 support material 110, making it a dried layer on the Al2O3 support material 110. Various combinations of Pd and support materials are envisioned, leading to various formulations of Pd catalyst materials. In a first embodiment of the Pd catalyst material, 0.8Pd-20Ce... n Pr 1-n O x / 10CA can be described as 0.8 wt% Pd and 20% Ce on a 10CA support calcined at 550°C for 2 hours. n Pr 1-n O x (n=1, 0.95, 0.9, 0.8, or 0.7) co-IWI. In the second embodiment of the Pd catalyst material, 0.8Pd-20Ce 0.9 Pr 0.1 O x It can be described as 0.8% by weight Pd and 20% Ce calcined at 550°C for 2 hours. 0.9 Pr 0.1 O x The co-IWI can be used on any of the following vectors: 10CeAlO y 30CeAlO y、 30CeAlO y -950, Al2O3-HD and M O x -Al2O3. In the third embodiment of the Pd catalyst material, 0.8Pd-30Ce 0.9 Pr 0.1 O x It can be described as 0.8% by weight Pd and 30% Ce calcined at 550°C for 2 hours. 0.9 Pr 0.1 O x The co-IWI can be used on any of the following vectors: Al2O3-HD and M O x -Al2O3.

[0127] Figure 8 is a graph 700 showing infrared spectroscopy analysis of various three-way catalysts including different concentrations of Pd deposited on the three-way catalysts according to the disclosed methods. The horizontal axis 702 shows wave number (measured in cm -1 The vertical axis 704 shows normalized absorbance (measured in arbitrary units (Au)). Curve 710 shows 0.2 Pd (500°C oxidation). Curve 720 shows 0.4 PD (500°C oxidation). Curve 730 shows 0.6 PD (500°C oxidation). Curve 740 shows 1.2 PD (500°C oxidation). The wave number of 2144 cm -1 corresponds to CO stretching vibration on Pd cations (characteristic of monatomic Pd species). The wave number of 2108 cm -1 corresponds to CO stretching vibration on Pd clusters (characteristic of sub-nanometer Pd clusters). According to the disclosed methods, graph 700 shows that the use of colloidal Ce02precursor and Pr co-impregnation results in formation of significantly smaller Ce02particles and high defect density, thereby minimizing formation of large Pd particles.

[0128] Figure 9is a graph 600 illustrating deactivation of palladium particles on a first three-way catalyst including a baseline palladium dispersion and on a second three-way catalyst including a palladium dispersion according to the disclosed methods. The graph 600 includes a horizontal axis 602 representing time of use of the three-way catalyst. The graph 600 also includes a vertical axis 604 representing percentage dispersion of activated Pd particles on the three-way catalyst. A curve 610 represents percentage of activated Pd particles on a three-way catalyst including a baseline palladium dispersion over time, where the three-way catalyst is produced without the benefit of the disclosed methods. The curve 610 begins at an approximate 50% dispersion of activated Pd particles, representing a three-way catalyst including Pd bulk or aggregated particles having an average diameter or thickness of 3-5 nanometers. With such Pd aggregated particles, not all Pd atoms are exposed and available as catalyst, and yet these particles deactivate over time. Further, the particles of Pd do not have a Ce layer separating the Pd particles from the support material, such as AI2O3. As a result, the Pd particles represented by the curve 610 deactivate at a relatively fast rate. A curve 620 represents percentage of activated Pd particles on a three-way catalyst over time, where the three-way catalyst is produced according to the disclosed methods. The curve 620 begins at a left-hand position representing an initial state of the three-way catalyst, 100% or near 100% dispersion, representing Pd dispersed on the surface of the three-way catalyst as single-atom Pd particles. The extensive dispersion of single-atom Pd particles and the layer of Ce-containing material separating the Pd particles from the support material enables the three-way catalyst represented by the curve 620 to resist deactivation of the Pd particles over time better than the three-way catalyst represented by the curve 610, resulting in a relatively slower rate of deactivation of Pd particles on the three-way catalyst represented by the curve 620. As a result, the three-way catalyst having the structure described herein and / or produced according to the methods disclosed herein, as represented by the curve 620, begins at a higher percentage of dispersion than the three-way catalyst represented by the curve 610 and deactivates at a relatively slower rate over time. As a result, the three-way catalyst having the structure described herein and / or produced according to the methods disclosed herein can include a reduced Pd loading compared to the three-way catalyst including a baseline palladium dispersion.

[0129] A method of making a three-way catalyst is provided. The method includes producing a palladium catalyst material. Producing the palladium catalyst material includes selecting a support material in powder form, the support material formed from a material selected from the group including: 10% CeO2 / Al2O3, 20% CeO2-Al2O3 (20CeAlOy), 30% CeO2-Al2O3 (30CeAlOy), 40% CeO2-Al2O3 (40CeAlOy), 50% CeO2-Al2O3 (50CeAlOy), 60% CeO2-Al2O3 (60CeAlOy), 70% CeO2-Al2O3 (70CeAlOy), 80% CeO2-Al2O3 (80CeAlOy), 90% CeO2-Al2O3 (90CeAlOy), 95% CeO2-Al2O3 (95CeAlOy), 99% CeO2-Al2O3 (99CeAlOy), AI2O3, and y ), AI2O3, and M O x -Al2O3, where Mis a metal and includes at least one of copper, iron, manganese, titanium, zirconium, magnesium, strontium, and barium. Producing the palladium catalyst material further includes providing a Ce-containing material layer on a surface of the support material to form a workpiece, and calcining the workpiece. Producing the palladium catalyst material further includes providing a CeO2layer on the support surface and the Ce-containing material layer to form a precursor, the CeO2layer having a first surface, and calcining the precursor to form a calcined precursor. Producing the palladium catalyst material further includes disposing a liquid co-impregnation composition on the calcined precursor to form a product, wherein the liquid co-impregnation composition includes CeO2, praseodymium, and palladium, and calcining the product to produce a plurality of CeO2structures projecting upward from the first surface and an active component on the product. Each of the plurality of CeO2structures has a second surface. The active component includes a first layer of praseodymium particles disposed on and dispersed throughout the second surface of each of the plurality of CeO2nanostructures and a second layer of a plurality of palladium particles disposed on and dispersed throughout the second surface of each of the plurality of CeO2nanostructures at a plurality of locations, each of the plurality of locations corresponding to a respective location of each of the plurality of praseodymium particles. The method further includes producing a slurry with the palladium catalyst material, coating an inert substrate of a three-way catalyst with the slurry, and drying the slurry on the inert substrate.

[0130] The active component can be z Pd-5Ce n Pr 1-n O x where z is 0.1 to 1.5, δ is 5 to 40, and n is 0.70 to 0.95.

[0131] The active component can be 0.8Pd-20Ce 0.90 Pr 0.10 O x .

[0132] The active component can be 0.8Pd-30Ce 0.90 Pr 0.10 O x .

[0133] While the best mode has been described in detail, those familiar with the art to which this disclosure relates will recognize various alternative designs and embodiments for practicing the present disclosure within the scope of the appended claims.

Claims

1. A three-way catalyst for reducing palladium loading, the three-way catalyst comprising: Inert substrate; and The palladium catalyst material coated on the inert substrate, the palladium catalyst material comprising: Carrier materials formed from materials selected from the group consisting of: 10% CeO2 / Al2O3, 20% CeO2-Al2O3, 30% CeO2-Al2O3, Al2O3, and... M Ox-Al2O3, wherein M is a metal including at least one of copper, iron, manganese, titanium, zirconium, magnesium, strontium and barium; A CeO2 material layer disposed on the carrier material and having a surface, wherein the CeO2 material layer is dispersed on the surface of the carrier material; and Active components, including: A first layer of praseodymium oxide particles is disposed on the surface of the CeO2 material layer and dispersed throughout the surface; and The second layer consists of multiple palladium particles disposed at multiple locations on the surface of the CeO2 material layer and dispersed throughout the surface, each of the multiple locations corresponding to a corresponding location of each of the multiple praseodymium particles.

2. The three-way catalyst according to claim 1, wherein, The CeO2 material layer is a CeO2 base layer; The surface of the CeO2 material layer is the first surface; The CeO2 substrate includes a plurality of CeO2 nanostructures protruding upward from the first surface, and each nanostructure has a second surface; The first layer of praseodymium particles is disposed on the second surface of each of the plurality of CeO2 nanostructures and dispersed throughout the second surface; and In this process, multiple palladium particles in the second layer are disposed on the second surface of each of the multiple CeO2 nanostructures and dispersed throughout the second surface.

3. The three-way catalyst according to claim 1, wherein, The carrier material is 10% CeO2 / Al2O3, which is formed by impregnating Ce nitrate onto Al2O3 and then calcining it at a temperature of 500°C to 1050°C for 1 to 5 hours.

4. The three-way catalyst according to claim 1, wherein, The carrier material is 10% CeO2 / Al2O3, which is produced by impregnating Ce nitrate onto Al2O3 and then calcining it at 950°C for two hours.

5. The three-way catalyst according to claim 1, wherein, The carrier material is 10% CeO2 / Al2O3, which is produced by impregnating Ce nitrate into Al(OH)2. x It is produced by calcining at 550°C for 2 hours.

6. The three-way catalyst according to claim 1, wherein, The carrier material is 30% CeO2-Al2O3.

7. The three-way catalyst according to claim 6, wherein, The carrier material was calcined at a temperature of 500℃ to 1050℃ for two hours.

8. The three-way catalyst according to claim 1, wherein, The carrier material is 30% CeO2-Al2O3 calcined at 950°C for two hours.

9. The three-way catalyst according to claim 1, wherein, The carrier material is M O x -Al2O3.

10. The three-way catalyst according to claim 9, wherein, The carrier material was calcined at 550°C for two hours.

11. The three-way catalyst according to claim 1, wherein, The active ingredient is z Pd-δCe n Pr 1-n O x , where z is 0.1 to 1.5, δ is 5.0 to 40, and n is 0.70 to 0.

95.

12. The three-way catalyst according to claim 1, wherein, The active ingredient is selected from the group consisting of: 0.8Pd-20Ce 0.90 Pr 0.10 O x and 0.8Pd-30Ce 0.90 Pr 0.10 O x .

13. The three-way catalyst according to claim 1, wherein, The second layer consists of multiple palladium particles formed from palladium single atoms.

14. An apparatus comprising: An internal combustion engine, which is configured to generate untreated exhaust gas; and A catalytic converter including a three-way catalyst, wherein the three-way catalyst promotes a chemical reaction to convert untreated waste gas into treated waste gas, the three-way catalyst comprising: Inert substrate; and The palladium catalyst material coated on the inert substrate, the palladium catalyst material comprising: Carrier materials formed from materials selected from the group consisting of: 10% CeO2 / Al2O3, 20% CeO2-Al2O3, 30% CeO2-Al2O3, Al2O3, and... M Ox-Al2O3, wherein M is a metal and includes at least one of copper, iron, manganese, titanium, zirconium, magnesium, strontium and barium; A CeO2 material layer disposed on the carrier material and having a surface, wherein the CeO2 material layer is dispersed on the surface of the carrier material; and Active components, including: A first layer of praseodymium oxide particles is disposed on the surface of the CeO2 material layer and dispersed throughout the surface; and The second layer consists of multiple palladium particles disposed at multiple locations on the surface of the CeO2 material layer and dispersed throughout the surface, each of the multiple locations corresponding to a specific location of each of the multiple praseodymium particles.

15. The apparatus according to claim 14, wherein, The active ingredient is z Pd-δCe n Pr 1-n O x , where z is 0.1 to 1.5, δ is 5.0 to 40, and n is 0.70 to 0.

95.

16. The apparatus according to claim 14, wherein, The active component is 0.8Pd-20Ce. 0.90 Pr 0.10 O x .

17. The apparatus according to claim 14, wherein, The active component is 0.8Pd-30Ce. 0.90 Pr 0.10 O x .

18. The apparatus according to claim 14, wherein, The second layer consists of multiple palladium particles formed from palladium single atoms.

19. A method for manufacturing a three-way catalyst, the method comprising: Materials for producing palladium catalysts include: Select a carrier material in powder form, said carrier material being formed from materials selected from the group consisting of: 10% CeO2 / Al2O3, 20% CeO2-Al2O3, 30% CeO2-Al2O3, Al2O3, and... M Ox-Al2O3, where M It is a metal and includes at least one of copper, iron, manganese, titanium, zirconium, magnesium, strontium and barium; A Ce-containing material layer is provided on the surface of the carrier material; The calcination includes the carrier material comprising a Ce-containing material layer disposed on the surface; A CeO2 layer is provided on the carrier surface and the Ce-containing material layer to form a precursor, the CeO2 layer having a first surface; The precursor is calcined to form a calcined precursor; A liquid co-impregnation composition is disposed on the calcined precursor to form a product, wherein the liquid co-impregnation composition comprises CeO2, praseodymium, and palladium; The product is calcined to produce a plurality of CeO2 structures protruding upward from the first surface and an active component on the product, wherein each of the plurality of CeO2 structures has a second surface, and the active component comprises: A first layer of praseodymium particles is disposed on the second surface of each of the plurality of CeO2 nanostructures and dispersed throughout the second surface; and The second layer consists of multiple palladium particles disposed at multiple locations on the second surface of each of the multiple CeO2 nanostructures and dispersed throughout the second surface, each of the multiple locations corresponding to a corresponding location of each of the multiple praseodymium particles. The slurry is produced using palladium catalyst materials; The slurry is used to coat the inert substrate of the ternary catalyst; and The slurry is dried on the inert substrate.

20. The method according to claim 19, wherein, The active component is zPd-δCe n Pr 1-n O x , where z is 0.1 to 1.5, δ is 5.0 to 40, and n is 0.70 to 0.95.

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