Particulate filter

Abstract

This disclosure generally relates to filters, methods, and systems for filtering particulate matter from the exhaust of internal combustion engines such as gasoline direct injection engines, as well as methods for preparing particulate filters.

Description

Technical Field

[0001] This disclosure generally relates to filters, methods, and systems for filtering particulate matter from the exhaust of internal combustion engines such as gasoline direct injection engines, as well as methods for preparing particulate filters. Background Technology

[0002] For particulate filters, high green filtration efficiency (>80%) will necessitate stricter particulate emission standards, such as EU6 (6x10⁻⁶). 11 (particulate matter / km). In this regard, gasoline internal combustion engines such as gasoline direct injection (GDI) engines can emit up to ten times more harmful fine particulate matter than port fuel injection (PFI) engines, especially during cold starts. Current gasoline particulate filter (GPF) technology typically involves ceramic filter substrates with or without a washcoat. Alternative technologies include metal fibers and foam. At low mileage, filtration efficiency is at its lowest level before any material is collected in the filter. Filtration efficiency is generally improved when smoke particles and non-combustible ash are collected. Several techniques have been used to improve the filtration efficiency of filter substrates in their fresh state, including changing the geometry (diameter and length), pore density, wall thickness, pore size, particle size distribution, and / or porosity of the filter substrate, and in the case of metal filters, including fibers or particle size. However, the higher efficiency achieved by these methods often results in higher back pressure losses, and there is often limited space in the vehicle that determines the overall size of the filter. Higher coating loading is considered another method to improve filtration efficiency. In this technique, a suspension based on ceramic powder is prepared to coat a substrate filter at loads ranging from a few grams per cubic inch. This technique still results in high back pressure loss with limited improvement in particulate filtration efficiency. Furthermore, coating techniques are still being optimized to balance the limited filtration efficiency improvement at low coating loads with the high back pressure loss at high coating loads. Summary of the Invention

[0003] This disclosure generally relates to filters, methods, and systems for filtering particulate matter from the exhaust of internal combustion engines such as GDI engines, as well as methods for preparing particulate filters.

[0004] Engine exhaust particulate filters are disclosed in various embodiments, comprising: a porous substrate having inert nanoparticles thereon having a filter volume concentration relative to the substrate ranging from 0.01 g / L to 60 g / L, a portion of the nanoparticles being arranged to form an anti-regenerative porous structure configured to trap particulates from the exhaust stream.

[0005] Engine exhaust particulate filters are disclosed in various embodiments, comprising: a porous substrate having thereon inert nanoparticles at a filter volume concentration ranging from 0.01 g / L to 60 g / L relative to the substrate, wherein a portion of the inert nanoparticles configured to remain attached during substrate regeneration is effective for capturing particulates from the exhaust stream.

[0006] Various embodiments disclose methods for preparing engine exhaust particulate filters, comprising: immersing nanoparticles in a carrier gas at a concentration in the range of 1 hr. -1 Up to 2,000,000 hr -1 The spatial velocity flow passes through the porous substrate to deposit nanoparticles with a filter volume concentration ranging from 0.01 g / L to 60 g / L relative to the substrate, and to generate a regenerable porous structure with a porosity of 70% or higher.

[0007] Various embodiments disclose internal combustion engine systems or vehicles including an internal combustion engine and an engine exhaust particulate filter of any embodiment, the engine exhaust particulate filter being configured to receive exhaust flow from the internal combustion engine. The exhaust flow in various embodiments includes particulates.

[0008] Various embodiments disclose methods for filtering particulate matter from an exhaust stream, comprising: guiding an exhaust stream from an internal combustion engine through an engine exhaust particulate filter of any embodiment, wherein the engine exhaust particulate filter removes particulate matter from the exhaust stream. Attached Figure Description

[0009] To further understand the nature, objectives, and advantages of the present invention, reference should be made to the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals denote like elements, and in the drawings:

[0010] Figure 1 Various embodiments of particulate filtration systems are shown.

[0011] Figure 2 This illustrates a cylindrical wall-flow monolith.

[0012] Figure 3A , Figure 3B , Figure 3C and Figure 3D Views of various embodiments of particulate filters with nanoparticles are shown.

[0013] Figure 4 Cross-sectional views of single-channel particulate filters with nanoparticles according to various embodiments are shown.

[0014] Figure 5 The particle size distribution of nanoparticles in various embodiments is shown.

[0015] Figure 6 The particle size distributions of nanoparticles prepared from precursor compounds in various embodiments are shown.

[0016] Figure 7 Views of aggregated nanoparticles in various embodiments are shown.

[0017] Figure 8 and Figure 9 This is an illustration showing various embodiments of nanoparticles forming porous structures on the outer surface and inside the pores of the filter wall of a porous filter substrate.

[0018] Figure 10A A view of 1 g / L nanoparticles deposited on a filter wall at 1000x magnification is shown. Reference lengths of 25 µm and 50 µm are also shown.

[0019] Figure 10B A view of 1 g / L nanoparticles deposited on a filter wall at 5000x magnification is shown. Reference lengths of 5 µm and 10 µm are also shown.

[0020] Figure 10C A view of 5 g / L nanoparticles deposited on a filter wall at 1000x magnification is shown. Reference lengths of 25 µm and 50 µm are also shown.

[0021] Figure 10D A view of 5 g / L nanoparticles deposited on a filter wall at 5000x magnification is shown. Reference lengths of 5 µm and 10 µm are also shown.

[0022] Figure 11 Systems for depositing nanoparticle suspensions onto porous filter substrates are shown in various embodiments.

[0023] Figure 12 Systems for depositing aggregated nanoparticles onto a porous filter substrate are shown in various embodiments.

[0024] Figure 13 Various embodiments of particulate filters calcined in a hot furnace are shown.

[0025] Figure 14 Various embodiments of systems for removing unstable or agglomerated nanoparticles from porous filter substrates are shown.

[0026] Figure 15A and Figure 15B Various embodiments of vehicle or engine systems are shown, including particulate filters connected to an internal combustion engine.

[0027] Figure 16 and Figure 17 This is a graph comparing the particle filtration efficiency of particle filters with and without nanoparticles in various embodiments.

[0028] Figure 18 This is a graph comparing the back pressure changes of particulate filters with and without nanoparticles in various embodiments.

[0029] Figure 19 and Figure 22 This is a graph comparing the particle filtration efficiency of various embodiments of a particle filter with nanoparticles, a particle filter without nanoparticles, and a particle filter with a conventional coating.

[0030] Figure 20 and Figure 23 This is a graph comparing the particulate emissions of various embodiments of particulate filters with nanoparticles, particulate filters without nanoparticles, and particulate filters with conventional coatings.

[0031] Figure 21 and Figure 24 This is a graph comparing the calculated back pressures of various embodiments of particulate filters with nanoparticles, particulate filters without nanoparticles, and particulate filters with conventional coatings. Detailed Implementation

[0032] As requested, detailed embodiments of this disclosure are provided herein; however, it should be understood that the disclosed embodiments are merely exemplary and may be embodied in various forms and alternative forms. The drawings are not necessarily drawn to scale; some features may be enlarged or minimized to show details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art.

[0033] Except as provided in the examples or otherwise expressly indicated, all numerical quantities representing amounts of material or reaction and / or conditions of use in this specification shall be understood to be modified by the word “about”. The first definition of an acronym or other abbreviation applies to all subsequent uses of the same acronym herein, and After making the necessary changes The normal grammatical variant of the abbreviation as originally defined applies; and unless explicitly stated otherwise, the measurement of a property is determined by the same technique used previously or subsequently for the same property.

[0034] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0035] It should also be understood that this disclosure is not limited to the specific embodiments and methods described below, as specific components and / or conditions may vary. Furthermore, the terminology used herein is for describing particular embodiments only and is not intended to be limiting in any way.

[0036] It must also be noted that, unless the context clearly specifies otherwise, the singular forms “a,” “an,” and “the” as used in this specification and the appended claims include a plural of indicators. For example, references to a component in the singular are intended to include multiple components.

[0037] The term "or" can be understood as meaning "at least one of...". The term "and" can also be understood as meaning "at least one of..." or "all...".

[0038] The terms “nanoparticles” and “microparticles” are used interchangeably to identify particles with a size or diameter of less than 1 micrometer (µm).

[0039] The terms “catalytic function,” “catalyst,” or “catalyst nanoparticles” should be understood to mean catalytic reactions, such as the oxidation or decomposition of particles, such as smoke particles or other emissions, such as nitrogen oxides.

[0040] The term "inert" or "inert nanoparticles" should be understood to mean that they do not have catalytic function.

[0041] The terms “engine exhaust particulate filter,” “particulate filter,” “green particulate filter,” “gas particulate filter,” or “filter substrate” are used interchangeably to identify zero- or low-mileage particulate filters, new particulate filters, or new filter substrates that have not previously been used to filter exhaust from internal combustion engines such as GDI engines.

[0042] The terms “porous substrate” or “porous filter substrate” are used interchangeably to identify the substrate and filter used as components in engine exhaust particulate filters.

[0043] The terms “internal combustion engine exhaust” and “exhaust flow” are used interchangeably to identify exhaust or gas / gas flow from an internal combustion engine, where the exhaust or gas / gas flow may include particulate matter. For example, particulate matter may include smoke particles generated by combustion.

[0044] The term “deposition” or “being deposited” can also be understood as attached to or placed within.

[0045] The term “one or more parts of” can also be understood to include “some of”, “a part of”, “all of”, or “the whole of”.

[0046] This disclosure generally relates to filters, methods, and systems for filtering particulate matter from the exhaust of internal combustion engines such as GDI engines, as well as methods for preparing particulate filters.

[0047] Various embodiments disclose particulate filters comprising: a porous filter substrate; and nanoparticles deposited on the substrate and arranged to form a porous structure; wherein the structure is configured to filter particulates from internal combustion engine exhaust. The structures of various embodiments are attached to the outer surface of the substrate or disposed within pores in the substrate.

[0048] Engine exhaust particulate filters are disclosed in various embodiments, comprising: a porous substrate having inert nanoparticles thereon having a filter volume concentration relative to the substrate ranging from 0.01 g / L to 60 g / L, a portion of the nanoparticles being arranged to form an anti-regenerative porous structure configured to trap particulates from the exhaust stream.

[0049] Various embodiments disclose particulate filters comprising: a porous filter substrate; and a certain concentration of nanoparticles deposited on the porous filter substrate; wherein the certain concentration of nanoparticles is effective for filtering particulates from internal combustion engine exhaust.

[0050] Engine exhaust particulate filters are disclosed in various embodiments, comprising: a porous substrate having thereon inert nanoparticles at a filter volume concentration ranging from 0.01 g / L to 60 g / L relative to the substrate, wherein a portion of the inert nanoparticles configured to remain attached during substrate regeneration is effective for capturing particulates from the exhaust stream.

[0051] Figure 1 Examples of particulate filtration systems 10 according to various embodiments are shown, including an intake manifold 11 having a cavity 14 connected to an inlet 12 and an outlet 13. The cavity 14 is sized sufficiently to house a particulate filter 100 according to various embodiments. In operation, the inlet 12 directs internal combustion engine exhaust 116 to the particulate filter 100, whereby the particulate filter 100 removes particulates from the exhaust 116. The filtered exhaust 118 exits the manifold 11 through the outlet 13.

[0052] The particulate filter in various embodiments is a porous filter substrate 101 capable of filtering particulate matter (e.g., smoke particles) from internal combustion exhaust. The porous filter substrate 101 has porous walls 103, wherein the pores of the porous walls 103 may have a pore size greater than 1 µm. For example, the pore size may range from 10 µm to 20 µm. The porous filter substrate 101 may also have a porosity of, for example, 45% or higher. Figure 2The example of a porous filter substrate shown is a cylindrical wall-flow monolithic block 104 having channels 102 and porous walls 103. The porous filter substrates of various embodiments may also be made of various materials, including, for example, cordierite (2MgO-2Al2O3-5SiO2), silicon carbide (SiC), or aluminum titanate (Al2TiO5).

[0053] Figure 3A , Figure 3B , Figure 3C and Figure 3D Cross-sectional views of a particulate filter 100, including a porous filter substrate 101 with nanoparticles 200, are shown in various embodiments. Figures 3A to 3D As shown, the porous filter substrate 101 has an inlet channel 111 and an outlet channel 112 separated by a filter wall 113. Figures 3A to 3D As shown, the inlet channel 111 and the outlet channel 112 have plugs 114 and 115 on opposite ends of the filter substrate 101.

[0054] like Figure 3A and Figure 3B As shown, particulate-laden exhaust gas 116 from the engine flows into the inlet channel 111 of the porous filter substrate 101, wherein a blocking end 114 of the inlet channel 111 prevents the particulate-laden exhaust gas 116 from leaving the inlet channel 111. The particulate-laden exhaust gas 116 flows through the filter wall 113 117 and into the outlet channel 112, where the particulates are removed from the exhaust gas 118. The filter wall 113 is porous (i.e., a porous wall) or comprises a porous material. Figures 3A to 3D As shown, nanoparticles 200 are deposited onto filter wall 113, and the nanoparticles 200 may be present on the outer surface of filter wall 113 or within filter wall 113. Nanoparticles 200 within filter wall 113 may include deposits on the material or within the pores. Optionally, nanoparticles 200 may also be deposited on the outer surface of plugs 114, 115. The outer surface may include the filter wall 113 or the surface of plugs 114, 115 adjacent to inlet 111 or outlet 112, said surface being exposed to exhaust 116, 118. Figure 3D As shown, the filter wall 113 may also include a catalyst 119, which is capable of catalyzing the redox reaction with reactants in the exhaust gas 116.

[0055] Figure 4 A cross-sectional view is shown of another example of a particulate filter system 10' including single-channel porous filter substrates 100 and 101' with nanoparticles 200. The single-channel particulate filter 101' includes an inlet channel 111' with a plug 114' and one or more outlets or one or more outlet channels 112'. The inlet channel 111' and the one or more outlets 112' are separated by a filter wall 113'. Figure 4As shown, particulate-laden exhaust 116 from the engine flows through inlet 12 into inlet passage 111', where a blocked end 114' of inlet passage 111' prevents the particulate-laden exhaust 116 from leaving inlet passage 111'. The particulate-laden exhaust 116 flows through filter wall 117 and into outlet 112', where the particulates are removed from exhaust 118. Exhaust 118 flows from intake manifold 11 through outlet 13. Nanoparticles 200 are deposited on filter wall 113', and nanoparticles 200 may be present on or within the filter wall 113'. Nanoparticles 200 within filter wall 113' may include deposits on or within pores. Optionally, nanoparticles 200 may also be deposited on the outer surface of plug 114'. The outer surface may include the filter wall 113' or the surface of plug 114' adjacent to inlet 111' or outlet 112', said surface being exposed to exhaust 116, 118.

[0056] Nanoparticles are deposited onto a porous filter substrate in various embodiments. In these embodiments, the nanoparticles are of a variety of different types. Differences in the nanoparticles may include, for example, different sizes, shapes, or the inclusion of different compounds.

[0057] In various embodiments, the nanoparticles have a median particle size ranging from 1 nm to 500 nm. Alternatively, the nanoparticles in various embodiments have a particle size ranging from 1 nm to less than 1 µm.

[0058] As previously described, the nanoparticles in various embodiments have a particle size, average / mean particle size, or median particle size of less than 1 µm. In various embodiments, the particle size, average / mean particle size, or median particle size of the nanoparticles is 0.5 nm, 1 nm, 3 nm, 5 nm, 10 nm, 30 nm, 40 nm, 70 nm, 80 nm, 90 nm, 100 nm, 130 nm, 180 nm, 230 nm, 250 nm, 280 nm, 500 nm, 750 nm, 900 nm, 950 nm, 975 nm, or less than 1000 nm. In various embodiments, the particle size, average / mean particle size, or median particle size of the nanoparticles falls within the range between any two particle sizes listed above. Figure 5 and Figure 6 An example of particle size distribution is shown in the figure. Figure 7 The particle size 210 of nanoparticle 200 is also shown.

[0059] In various embodiments, the nanoparticles are formed from aggregated nanoparticles. The aggregated nanoparticles in various embodiments have a particle size, average / mean particle size, or median particle size of 200 µm or less. The particle size, average / mean particle size, or median particle size of the aggregated nanoparticles in various embodiments is 0.05 µm, 0.1 µm, 0.5 µm, 1 µm, 2 µm, 3 µm, 4 µm, 5 µm, 6 µm, 7 µm, 8 µm, 9 µm, 10 µm, 20 µm, 30 µm, 40 µm, 50 µm, 60 µm, 70 µm, 80 µm, 90 µm, 100 µm, 110 µm, 120 µm, 130 µm, 140 µm, 150 µm, 160 µm, 170 µm, 180 µm, 190 µm, or 200 µm.

[0060] In various embodiments, the particle size, average / mean size, or median size of the aggregated nanoparticles falls within the range of any two particle sizes listed above. Figure 7 The particle size 230 of the aggregated nanoparticles 220 is shown.

[0061] In various embodiments, the aggregated nanoparticles have a porosity of 50% or higher. In various embodiments, the porosity of the aggregated nanoparticles is 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%. In various embodiments, the porosity of the aggregated nanoparticles is within the range between any two porosities listed above.

[0062] The nanoparticles in various embodiments include various catalyst nanoparticles with catalytic functions or various inert particles, which may include various metal nanoparticles. For example, catalytic functions may include catalytic reactions such as the oxidation or decomposition of particles, such as smoke particles or other emissions, such as nitrogen oxides (e.g., nitrous oxide gas (N₂O)). Examples of materials with catalytic functions include rhodium, platinum, palladium, ruthenium, or silver. For example, inert or metal nanoparticles may be understood to mean that they do not have catalytic functions.

[0063] In other embodiments, the inert or metallic particles may be impregnated with other metallic particles and / or particles with catalytic functionality. In other embodiments, the nanoparticles include metals, such as metal oxides, transition metals, post-transition metals, metalloids, lanthanides, or rare earth metals. Examples include alumina, silicon dioxide, titanium dioxide, zirconium oxide, or cerium dioxide.

[0064] The nanoparticles in various embodiments may include, for example, metal particles, metal oxide particles, alumina particles (or γ-alumina), silica particles, titanium dioxide particles, zirconium oxide particles, cerium dioxide particles, iron oxide particles, or combinations thereof. The metal particles in various embodiments may also be understood to include, for example, metal oxide particles, alumina particles (or γ-alumina), silica particles, titanium dioxide particles, zirconium oxide particles, cerium dioxide particles, iron oxide particles, or combinations thereof. In various embodiments, the particles are porous or may include dopants. Examples of dopants may include transition metals such as iron, magnesium, rhodium, or platinum.

[0065] In various embodiments, the filter substrate may also include a catalyst, such as platinum, palladium, rhodium, cerium, iron, manganese, or nickel, deposited onto the porous walls.

[0066] In various embodiments, the concentration of nanoparticles relative to the filter volume of the substrate ranges from 60 g / L or lower. In various embodiments, the concentration range of nanoparticles relative to the filter volume of the substrate is 0.01 g / L, 0.02 g / L, 0.03 g / L, 0.04 g / L, 0.05 g / L, 0.06 g / L, 0.07 g / L, 0.08 g / L, 0.09 g / L, 0.1 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L, 0.5 g / L, 0.6 g / L, 0.7 g / L, 0.8 g / L, 0.9 g / L, 1 g / L, 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, 15 g / L, 20 g / L, 25 g / L, 30 g / L, 35 g / L, 40 g / L, 45 g / L, 50 g / L. g / L, 55 g / L, or 60 g / L. In various embodiments, the concentration of nanoparticles relative to the filter volume of the substrate ranges between any two concentrations listed above.

[0067] In such Figures 3A to 3D and Figure 4In the various embodiments shown, a certain concentration of nanoparticles, or a portion of nanoparticles, is stably attached to the porous filter substrate, such that the nanoparticles remain attached during particulate filter regeneration to remove trapped particles. Regeneration can occur for extended periods at high temperatures (approximately 600 °C), including 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, or 40 minutes. In the various embodiments, the regeneration time of the particulate filter falls within the range of any two times listed above.

[0068] In various embodiments, the portion of nanoparticles that remains stably attached to the porous filter substrate after regeneration is 50% or higher, or 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%. In various embodiments, the portion of said portion that remains stably attached to the porous filter substrate after regeneration is within the range of any two percentages listed above. The portion of nanoparticles of a certain concentration in various embodiments can also be maintained attached through multiple regeneration intervals of the particulate filter. In other embodiments, a portion of the nanoparticles at a certain concentration remains adhered to the substrate for 50%, 60%, 70%, 80%, 90%, or 100% of the entire lifespan of the particulate filter. In various embodiments, the percentage of lifespan falls within the range of any two percentages listed above.

[0069] In various embodiments, the nanoparticles form a porous structure. Figure 8 and Figure 9 This is an illustration showing the deposition of nanoparticles 200 onto porous filter substrates 101, 101' in various embodiments to form a porous structure 300. (See illustration for further details.) Figure 8 As shown, the porous structure 300 may have the appearance of branching or dendritic structures 310 extending from the outer surface 160 of the filter walls 113, 113'. The branching or dendritic structures 310 may have protrusions 311, and the size of the branching or dendritic structures 310 may be nanoscale (<1 µm) or microscale (<1 mm). In various embodiments, the porous structure 300 is a plurality of branching structures 310 interconnected to form an interconnecting structure 320. Figure 9 As shown, the branch structure 310 can be bridged with different branch structures 310 or interconnect structures 320. Figure 9An interconnect structure 320 extending from the outer surface 160 of filter walls 113, 113' is shown. The size of the interconnect structure 320 can be microscale (<1 mm) or macroscale (≥ 1 mm). The interconnect structures of various embodiments may have an appearance similar to an interconnect fractal or mesh structure or a dendritic fractal structure. As disclosed, the porous structure of various embodiments refers to any structure including the branching or dendritic structure or interconnect structure of any embodiment.

[0070] Figure 8 and Figure 9 Various embodiments of nanoparticles 200 are also shown agglomerating into branched structures 310 or interconnected structures 320 within the pores 150 of the filter walls 113, 113'. The nanoparticles 200 of various embodiments are capable of being deposited throughout the entire depth of the porous filter substrates 101, 101'. In this regard, the nanoparticles 200 of various embodiments are deposited within the pores 150 of the filter walls 113, 113' and are capable of adhering to the surface 151 defining the pores 150 and forming agglomerates or branched structures 310 or interconnected structures 320 within the pores 150.

[0071] In various embodiments, the porous structure has a porosity of 70% or higher. In various embodiments, the porosity of the porous structure is 70%, 70.5%, 71%, 71.5%, 72%, 72.5%, 73%, 73.5%, 74%, 74.5%, 75%, 75.5%, 76%, 76.5%, 77%, 77.5%, 78%, 78.5%, 79%, 79.5%, 80%, 80.5%, 81%, 81.5%, 82%, 82.5%, 83%, 83.5%, 84 ... 4.5%, 85%, 85.5%, 86%, 86.5%, 87%, 87.5%, 88%, 88.5%, 89%, 89.5%, 90%, 90.5%, 91%, 91.5%, 92%, 92.5%, 93%, 93.5%, 94%, 94.5%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, or less than 100%. In various embodiments, the porosity of the porous structure is within the range of any two percentages listed above.

[0072] In various embodiments, at least a portion of the nanoparticles at a certain concentration forms a porous structure. The nanoparticles forming the porous structure, or a portion of the nanoparticles at a certain concentration, are 5%, 10%, 15%, 20%, 25%, 50%, 75%, 90%, 95%, or 100% nanoparticles. In various embodiments, the portion of the particles agglomerated into the porous structure is within the range of any two percentages of the nanoparticles listed above.

[0073] In various embodiments, a portion of the branch structure connected to form the interconnect structure is 5%, 10%, 15%, 20%, 25%, 50%, 75%, 90%, 95%, or 100% of the branch structure. In various embodiments, the percentage of the branch structure making the connection is within the range of any two percentages listed above.

[0074] In various embodiments, the porous structure is a regenerable porous structure, wherein the regenerable porous structure has the stability, such as temperature stability or mechanical / chemical strength, of the components used as particulate filters capable of regeneration to remove captured particles. Therefore, the regenerable porous structure is maintained during the regeneration of the particulate filter. The regenerable porous structures of various embodiments have sufficient stability or mechanical / chemical strength to withstand multiple regeneration intervals of the particulate filter. In other embodiments, the regenerable porous structure is capable of remaining on or within the filter substrate for 50%, 60%, 70%, 80%, 90%, or 100% of the entire service life of the particulate filter. In various embodiments, the percentage of service life is within the range of any two percentages listed above. Regeneration can occur for extended periods at high temperatures (approximately 600 °C), including 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, or 40 minutes. In various embodiments, the regeneration time of the particulate filter is within the range of any two times listed above.

[0075] Figure 10A , Figure 10B , Figure 10C and Figure 10D Views of nanoparticles 200 deposited on filter walls 113, 113' of porous filter substrates 101, 101' according to various embodiments are shown. Figure 10A and Figure 10B The surface morphology of filter walls 113, 113' of a porous filter substrate 101 (such as a cordierite filter) is shown, wherein a certain concentration of nanoparticles 200 is deposited on the outer surface 160 of the filter walls 113, 113'. Figure 10C and Figure 10D Similar to Figure 10A and Figure 10B However, the deposition of nanoparticles 200 onto the outer surface 160 of the filter walls 113, 113' results in a greater load. For example... Figures 10A to 10D As shown, a portion of the nanoparticles 200 aggregate on the filter walls 113, 113' into branched structures 310 (i.e., dendritic or coral-like structures). For example, as... Figures 10A to 10DAs shown, the branched structure 310, having multiple microparticle protrusions 311 (i.e., whiskers or fingers), further extends from the outer surface of the filter walls 113, 113'. Nanoparticles in various embodiments can be deposited onto the filter walls of the porous filter substrate, resulting in a uniform coating of the filter walls and / or the porous filter substrate.

[0076] Methods for preparing particulate filters are disclosed in various embodiments, comprising: immersing nanoparticles in a carrier gas at a concentration in the range of 1 hour. -1 Up to 2,000,000 hr -1 A spatial velocity flow passes through a porous filter substrate to deposit a certain concentration of nanoparticles onto the substrate; wherein the certain concentration of nanoparticles is effective for filtering particulate matter from internal combustion engine exhaust.

[0077] Various embodiments disclose methods for preparing engine exhaust particulate filters, comprising: immersing nanoparticles in a carrier gas at a concentration in the range of 1 hr. -1 Up to 2,000,000 hr -1 The spatial velocity flow passes through the porous substrate to deposit nanoparticles with a filter volume concentration ranging from 0.01 g / L to 60 g / L relative to the substrate, and to generate a regenerable porous structure with a porosity of 70% or higher.

[0078] The methods / processes of various embodiments generally involve a gas percolation process to coat nanoparticles onto a porous filter substrate to improve the green filtration efficiency for particulate emission control of internal combustion exhaust. Compared to other methods (such as coating or sol-gel processes), the methods / processes of various embodiments can achieve more targeted coatings with lower load equivalents. In various embodiments, either side or both sides of the porous wall adjacent to the inlet or outlet channel can be coated with particles using the methods / processes of various embodiments.

[0079] In various embodiments, the concentration of nanoparticles relative to the filter volume of the substrate is 60 g / L or lower. In various embodiments, the concentration of nanoparticles relative to the filter volume of the substrate is 0.01 g / L, 0.02 g / L, 0.03 g / L, 0.04 g / L, 0.05 g / L, 0.06 g / L, 0.07 g / L, 0.08 g / L, 0.09 g / L, 0.1 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L, 0.5 g / L, 0.6 g / L, 0.7 g / L, 0.8 g / L, 0.9 g / L, 1 g / L, 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, 15 g / L, 20 g / L, 25 g / L, 30 g / L, 35 g / L, 40 g / L, 45 g / L, 50 g / L. g / L, 55 g / L, or 60 g / L. In various embodiments, the concentration of nanoparticles relative to the filter volume of the substrate ranges between any two concentrations listed above.

[0080] In various embodiments, the flow step is performed at a spatial velocity ranging from 1 hr. -1 Up to 2,000,000 hr -1 10 hr -1 Up to 2,000,000 hr -1 100 hr -1 Up to 2,000,000 hr -1 or 1 hr -1 Up to 50,000 hr -1 In various embodiments, the spatial velocity of the flow step is 1 hr. -1 10 hr -1 50 hr -1 100 hr -1 200 hr -1 300 hr -1 400 hr -1 500 hr -1 600 hr -1 700 hr -1 800 hr -1 900 hr -1 1,000 hr -1 5000 hr -1 10,000 hr -1 20,000 hr -1 30,000 hr -140,000 hr -1 50,000 hr -1 100,000 hr -1 200,000 hr -1 300,000 hr -1 400,000 hr -1 500,000 hr -1 600,000 hr -1 700,000 hr -1 800,000hr -1 900,000 hr -1 1,000,000 hr -1 1,100,000 hr -1 1,200,000 hr -1 1,300,000 hr -1 1,400,000 hr -1 1,500,000 hr -1 1,600,000 hr -1 1,700,000 hr -1 1,800,000 hr -1 1,900,000 hr -1 Or 2,000,000 hr -1 In various embodiments, the spatial velocity of the flow step is within the range of any two spatial velocities listed above.

[0081] In various embodiments, the method for preparing the particulate filter further includes the steps of: atomizing a nanoparticle suspension prior to the flow and drying the atomized nanoparticles. The method in various embodiments may also include preparing the nanoparticle suspension. In various embodiments, a precursor compound for the particles in the suspension is atomized and dried to form particles.

[0082] In various embodiments, the weight percentage of particles in the suspension is 0.001%, 0.01%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, or 6%. In various embodiments, the weight percentage of particles is within the range of any two weight percentages listed above.

[0083] In various embodiments, the flow step is performed at a spatial velocity ranging from 1 hr. -1 Up to 50,000 hr -1 Or 1,000 hr -1Up to 50,000 hr -1 In various embodiments, the spatial velocity of the flow step is 1 hr. -1 10 hr -1 50 hr -1 100 hr -1 200 hr -1 300 hr -1 400 hr -1 500 hr -1 600 hr -1 700 hr -1 800hr -1 900 hr -1 1,000 hr -1 5000 hr -1 10,000 hr -1 20,000 hr -1 30,000 hr -1 40,000 hr -1 Or 50,000 hr -1 In various embodiments, the spatial velocity of the flow step is within the range of any two spatial velocities listed above.

[0084] The following illustrative examples illustrate the generation of nanoparticle suspensions in various embodiments. The suspension is prepared by dispersing boehmite nanoparticles in water. The suspension is atomized / sprayed using an atomizer and dried using a furnace or dryer. The particle size of the microparticles in various embodiments can be adjusted by changing the solids concentration of the suspension and the atomizer settings. Figure 5 As shown, for 1 wt% boehmite in the suspension, the resulting particles are nanoscale, with a peak (median) at approximately 70–80 nm. In other examples, as measured by a scanning mobility particle size analyzer (SMPS), the resulting particles show a particle size distribution from 5 to 500 nm, with an average particle size of approximately 100 nm. Optionally, the boehmite (but alumina) precursor is dissolved in water, and the pH is adjusted to approximately 4 with nitric acid. The mixture is vigorously mixed to form a clear solution. Similar to what has been previously described, the solution is atomized and dried. Figure 6 The particle size distribution of a solution containing 0.1% by weight of microparticles is shown, with the peak (median) of the particle size distribution being approximately 30-40 nm. Figure 16 and 17 The images show the filtration efficiency of the particulate filters prepared using these examples compared to the bare substrate.

[0085] The following illustrative examples illustrate methods for preparing particulate filters from nanoparticle suspensions in various embodiments. Figure 11A system 500 is shown for preparing particulate filters 100, 100' from a suspension 510 of nanoparticles 200. (Example) Figure 11 As shown, a nanoparticle suspension 510 is fluidly / gas-bound to porous filter substrates 101, 101'. The nanoparticle suspension 510 is atomized and combined with a carrier gas 512. Besides atomization, other techniques can be used to generate the particles, including, for example, spray drying, flame spray pyrolysis, or condensation. The atomized suspension 511 flows toward the porous filter substrates 101, 101' through a pipe / duct 513. The atomized suspension 511 may be dried in a dryer / furnace 514 before reaching the porous filter substrates 101, 101'. The atomized suspension 511 flows through the porous filter substrates 101, 101', where a certain concentration of nanoparticles is deposited onto the porous filter substrates 101, 101'. Nanoparticles not deposited on the porous filter substrates 101, 101' can be allowed to flow through the porous filter substrates 101, 101' and collected 516. In one example, the nanoparticles, whether diluted or undiluted, are then passed through a porous filter substrate (such as a ceramic filter), thereby trapping the nanoparticles within the porous filter substrate. The spatial velocity of the flow can be adjusted by selecting the filter size, varying the atomizer flow rate, and changing the flow rate of the diluent gas (air, nitrogen, or other inert gas). For example, depending on the properties of the aerosol (such as particle concentration, particle density, and particle size), a range of 1,000 to 50,000 hrs can be used. -1 Or even lower space velocities. Tests were conducted at particle loading equivalents of 1 g / L and 5 g / L. The space velocities could be controlled to sufficiently low points where diffusion is the mechanism for collecting nanoparticles, allowing for the formation of dendritic structures within the nanoparticles. Figure 10A and Figure 10B This shows the deposition of 1 g / L particles onto the filter wall of a porous filter substrate, and Figure 10C and Figure 10D This illustrates the deposition of 5 g / L nanoparticles onto the filter wall of a porous filter substrate. For nanoparticles with a median particle size of approximately 80 nm, the deposition was carried out at 4,000 hr. -1 Space velocity preparation Figures 10A to 10D The dendritic structure shown. Figures 10A to 10D It was also shown that increasing the load equivalent of nanoparticles led to an increase in the number and complexity of dendritic structures. Furthermore, the load equivalent was less than one-tenth of the typical coating load of approximately 60 g / L (or approximately 1 g / cubic inch filter).

[0086] In various embodiments, the nanoparticles include aggregated nanoparticles. For example, the nanoparticles used in the methods or processes of various embodiments may include both nanoparticles and aggregated nanoparticles.

[0087] The aggregated nanoparticles of various embodiments have a particle size, average / mean particle size, or median particle size of 200 µm or smaller. The particle size, average / mean particle size, or median particle size of the aggregated nanoparticles of various embodiments is 0.05 µm, 0.1 µm, 0.5 µm, 1 µm, 2 µm, 3 µm, 4 µm, 5 µm, 6 µm, 7 µm, 8 µm, 9 µm, 10 µm, 20 µm, 30 µm, 40 µm, 50 µm, 60 µm, 70 µm, 80 µm, 90 µm, 100 µm, 110 µm, 120 µm, 130 µm, 140 µm, 150 µm, 160 µm, 170 µm, 180 µm, 190 µm, or 200 µm. In various embodiments, the particle size, average / mean size, or median size of the aggregated nanoparticles falls within the range of any two particle sizes listed above. Figure 7 The particle size 230 of the aggregated nanoparticles 220 is shown.

[0088] In various embodiments, the aggregated nanoparticles have a porosity of 50% or higher. In various embodiments, the porosity of the aggregated nanoparticles is 50% or higher, or 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%. In various embodiments, the porosity of the aggregated nanoparticles is within the range between any two porosities listed above.

[0089] In various embodiments, the spatial velocity of the flow step is 10 hr. -1 50 hr -1 100 hr -1 200 hr -1 300hr -1 400 hr -1 500 hr -1 600 hr -1 700 hr -1 800 hr -1 900 hr -1 1,000 hr -1 5000 hr -1 10,000 hr-1 20,000 hr -1 30,000 hr -1 40,000 hr -1 or 50,000 hr -1 100,000 hr -1 200,000hr -1 300,000 hr -1 400,000 hr -1 500,000 hr -1 600,000 hr -1 700,000 hr -1 800,000 hr -1 900,000 hr -1 1,000,000 hr -1 1,100,000 hr -1 1,200,000 hr -1 1,300,000 hr -1 1,400,000 hr -1 1,500,000 hr -1 1,600,000 hr -1 1,700,000 hr -1 1,800,000 hr -1 1,900,000 hr -1 Or 2,000,000 hr -1 In various embodiments, the spatial velocity of the flow step is within the range of any two spatial velocities listed above.

[0090] In various embodiments, the flow of nanoparticle agglomerates includes separating or filtering the nanoparticle agglomerates. Separation or filtering of nanoparticle agglomerates in various embodiments may include separating / filtering nanoparticle agglomerates for a particle size or particle size range, wherein nanoparticle agglomerates of a size are deposited onto or not deposited onto a porous filter substrate, said size being the particle size, larger or smaller than said particle size, or within or outside said particle size range. In various embodiments, the particle size is 0.05 µm, 0.1 µm, 0.5 µm, 1 µm, 2 µm, 3 µm, 4 µm, 5 µm, 6 µm, 7 µm, 8 µm, 9 µm, 10 µm, 20 µm, 30 µm, 40 µm, 50 µm, 60 µm, 70 µm, 80 µm, 90 µm, 100 µm, 110 µm, 120 µm, 130 µm, 140 µm, 150 µm, 160 µm, 170 µm, 180 µm, 190 µm, or 200 µm. In various embodiments, the particle size range is between any two particle sizes listed above.

[0091] The following illustrative examples illustrate methods for preparing particulate filters of various embodiments from aggregated nanoparticles. Figure 12 A system 600 is shown for preparing particulate filters 100, 100' from aggregated nanoparticles 220. (Example) Figure 12As shown, agglomerated nanoparticles 220 are combined with a carrier gas 612. The agglomerated nanoparticles 220 are then flowed toward porous filter substrates 101, 101' through a pipe / duct 613. The agglomerated nanoparticles 220 are then flowed through porous filter substrates 101, 101', where a certain concentration of nanoparticles is deposited onto the porous filter substrates 101, 101'. The agglomerated nanoparticles 220 can also be selected by an aerosol separator before reaching the porous filter substrates 101, 101'. Selection using an aerosol separator allows the selection of agglomerated nanoparticles of a desired size. Examples of aerosol separators include cyclone separators or impactors. Agglomerated nanoparticles 220 that are not deposited on the porous filter substrates 101, 101' can be flowed through 615 of the porous filter substrates 101, 101' and collected 616. In one example, a fluidized bed aerosol generator is used to suspend alumina powder prepared by flame pyrolysis synthesis. Agglomerated nanoparticles are suspended in a carrier gas and flow through a porous filter substrate to deposit the agglomerates onto the substrate. In various embodiments, the nanoparticle size ranges from 5 nm to 50 nm, and the agglomerate size ranges from 1 µm to 20 µm. In other embodiments, the median particle size of the agglomerates ranges from 0.05 µm to 200 µm, and the median particle size of the nanoparticles ranges from 1 nm to 500 nm. In various embodiments, the agglomerates have high porosity (e.g., 70% or higher). The space velocity can range from 100 hr. -1 Up to 2,000,000 hr -1 .

[0092] In various embodiments, the method further includes calcining the porous filter substrate / particulate filter after flow. In various embodiments, calcination substantially simultaneously or simultaneously includes multiple porous filter substrates / particulate filters. Figure 13As shown, particulate filters 100 and 100' are calcined in a calcination furnace 700, wherein particulate filters 100 and 100' are heated by a heating element 701. In this example, the particulate filter containing nanoparticles is heat-treated. The heat treatment can bind the nanoparticles and also transform the particles into the desired phase. Optionally, the calcination of porous filter substrates / particulate filters can be performed on a large scale, wherein multiple porous filter substrates / particulate filters are calcined in a large furnace or a conveyor-type furnace. In these examples, the nanoparticles are transformed from boehmite to γ-alumina. In another example, the heat treatment is carried out in air with water vapor to promote bonding between particles. In various embodiments, the calcination temperature is 500 °C, 550 °C, 600 °C, 650 °C, 700 °C, 750 °C, 800 °C, 850 °C, 900 °C, 950 °C, 1000 °C, 1050 °C, 1100 °C, 1150 °C, or 1200 °C. The calcination temperature in various embodiments falls within the range of any two temperatures listed above. In various embodiments, the water vapor concentration during calcination is 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%. The water vapor concentration in various embodiments falls within the range of any two percentages listed above.

[0093] In various embodiments, the method further includes guiding the flow of the medium after flow to remove nanoparticles from the particulate filter. Figure 14 A system 800 for removing nanoparticles 200 or nanoparticle agglomerates from particulate filters 100, 100' is shown, wherein a gas or liquid 812 (such as a carrier gas in any embodiment) flows from a source 801 and through a fitting / pipe 813 and particulate filters 100, 100'. Any nanoparticles 200 or nanoparticle agglomerates 220 that are unstablely deposited onto porous filter substrates 101, 101' are removed 815 and collected 816. In one example, high flow (up to 3 x 10⁻⁶) is used. 6 hr -1 The flow (at spatial velocity) processes the filter containing the collected nanoparticles. The flow allows for the removal of unstable particle aggregates.

[0094] In various embodiments, the space velocity used to remove unstable nanoparticles or nanoparticle aggregates is 10 hr. -1 50 hr -1 100 hr -1 200 hr -1 300 hr -1 400 hr -1 500 hr-1 , 600 hr -1 , 700 hr -1 , 800 hr -1 , 900 hr -1 , 1,000 hr -1 , 5000 hr -1 , 10,000 hr -1 , 20,000 hr -1 , 30,000 hr -1 , 40,000 hr -1 , or 50,000 hr -1 , 100,000 hr -1 , 200,000 hr -1 , 300,000 hr -1 , 400,000 hr -1 , 500,000 hr -1 , 600,000 hr -1 , 700,000 hr -1 , 800,000 hr -1 , 900,000 hr -1 , 1,000,000 hr -1 , 1,100,000 hr -1 , 1,200,000 hr -1 , 1,300,000 hr -1 , 1,400,000 hr -1 , 1,500,000 hr -1 , 1,600,000 hr -1 , 1,700,000 hr -1 , 1,800,000 hr -1 , 1,900,000 hr -1 , or 2,000,000 hr -1 , 2,000,000 hr -1 , 2,100,000 hr -1 , 2,200,000 hr -1 , 2,300,000 hr -1 , 2,400,000 hr -1 , 2,500,000 hr -1 , 2,600,000 hr -1 , 2,700,000 hr -1 , 2,800,000 hr -1 , 2,900,000 hr-1 Or 3,000,000 hr -1 In various embodiments, the spatial velocity of the flow step is within the range of any two spatial velocities listed above.

[0095] Various embodiments disclose internal combustion engine systems or vehicles including an internal combustion engine and an engine exhaust particulate filter of any embodiment, the engine exhaust particulate filter being configured to receive exhaust flow from the internal combustion engine. Figure 15A The internal combustion engine system 900 within the motor vehicle 903 is shown. (Example) Figure 15B As shown, the internal combustion engine system 900 includes an internal combustion engine coupled to the particulate filter systems 10, 10'. In various embodiments, the internal combustion engine is a GDI or direct injection diesel engine.

[0096] Various embodiments disclose methods for filtering particulate matter from an exhaust stream, comprising: guiding an exhaust stream from an internal combustion engine through an engine exhaust particulate filter of any embodiment, wherein the engine exhaust particulate filter removes particulate matter from the exhaust stream. Figure 15A and Figure 15B As shown, particulate filtration systems 10, 10' receive exhaust gas containing particulates 116 via fittings or pipes 902, wherein particulate filtration systems 10, 10' remove particulates from exhaust gas 116. Filter exhaust gas 118 then exits particulate filtration systems 10, 10'.

[0097] Advantages of the particulate filters in various embodiments include, for example: controllable and effective improvement in green filtration efficiency (zero-mile efficiency); the ability to achieve green filtration efficiency of 80+%; low back pressure loss; and lower load on the coating material compared to other coating technologies (such as coatings). The following references are incorporated herein by reference in their entirety: Lambert, Christine, et al., “Gasoline Particle Filter Development,” Emission Control Science and Technology 3.1 (2017): 105-111.

[0098] In various embodiments, the particulate filter has a greater particulate filtration efficiency than a otherwise identical particulate filter that does not contain a certain concentration of nanoparticles.

[0099] In various embodiments, the particulate filter has a particulate filtration efficiency of 50% or higher for particles with a particle size of 1 µm or smaller. The particulate filtration efficiency of the particulate filter is 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, or 100%. In various embodiments, the particulate filtration efficiency is within the range of any two particulate filtration efficiencies listed above. In various embodiments, the particulate filtration efficiency relates to the filtration of particles with the following particle sizes: 5 nm, 10 nm, 30 nm, 40 nm, 70 nm, 80 nm, 90 nm, 100 nm, 130 nm, 180 nm, 230 nm, 250 nm, 280 nm, 300 nm, 500 nm, 750 nm, 900 nm, 950 nm, 975 nm, or 1000 nm. In various embodiments, the particle size is within the range of any two particle sizes listed above.

[0100] In various embodiments, the particulate filter has a back pressure at a flow rate that is at most 50% greater than the back pressure at that flow rate of a otherwise identical particulate filter that does not contain a certain concentration of nanoparticles. The particulate filter in various embodiments has a back pressure at a flow rate that is 0%, 0.001%, 0.1%, 1%, 5%, 10%, 20%, 30%, 40%, or 50% greater than the back pressure of a otherwise identical particulate filter that does not contain a certain concentration of nanoparticles. In various embodiments, the increase in back pressure is within the range of any two percentages listed above.

[0101] In various embodiments, the particulate filter has a back pressure at a certain flow rate, said back pressure being at most equal to 3.5 g / in (inch). 3 The back pressure at a given flow rate for particulate filters with or less coating load. In various embodiments, the back pressure at a given flow rate is 3.5 g / in. 3 The back pressure of the particulate filter at the specified flow rate is reduced by 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 200%, 300%, 400%, or 500%. In various embodiments, the reduction in back pressure is within the range of any two percentages.

[0102] In various embodiments, the coating load is 0.01 g / in. 3 0.1 g / in 3 0.5 g / in 3 1 g / in 31.5 g / in 3 2 g / in 3 2.5 g / in 3 3 g / in 3 Or 3.5 g / in 3 In various embodiments, the coating load is within the range of any two concentrations listed above.

[0103] Figure 16 and Figure 17 This graph compares the particle filtration efficiency of a filter substrate with different concentrations of nanoparticles deposited on the porous walls of the filter substrate, and a filter substrate without particles. For Figure 16 "■" represents a substrate coated with approximately 5 g / L of γ-alumina nanoparticles. " " represents a substrate coated with approximately 1 g / L of γ-alumina nanoparticles; and "▲" represents a bare substrate. For Figure 17 “■” represents the bare substrate, and “ "It is a substrate coated with nanoparticles. For example..." Figure 16 As shown, adding particles to the filter substrate improves the filtration of particles with a size range from less than 30 nm to 300 nm. Figure 17 This further demonstrates a significant increase in filtration efficiency for all carbon particulate matter.

[0104] Figure 18 This is a graph showing the change in back pressure (Dp) with and without nanoparticles. For Figure 18 “■” represents the bare substrate, and “ "It is a substrate containing nanoparticles. For example..." Figure 18 As shown, the addition of nanoparticles results in a small increase in back pressure for the particulate filter.

[0105] The following examples illustrate various embodiments of this disclosure. Those skilled in the art will recognize many variations within the spirit and scope of the claims.

[0106] The impact of particulate efficiency and back pressure on GDI engines

[0107] In one example, the 2.0 L GTDI engine was equipped with different GPFs and tested separately using the FTP75 cycle. Figure 19 The filtration efficiency is shown, determined by the smoke particle concentration before and after filtration. Coating a filter with approximately 0.5 g / L fine particles using current technology shows improved filtration efficiency compared to an uncoated filter, while conventional coating techniques achieve higher loading levels of approximately 1.5 g / L. 3 Coated filters have shown a negative impact on efficiency. For example... Figure 20As shown, for the coated GPF, the total particulate emissions at the exhaust tailpipe through the disclosed technology are significantly lower. Figure 21 Further, the back pressure at rated power predicted by measured permeability is shown, and the GPF coated with the new technology shows a slight increase in back pressure (about 8%), which is much smaller than the increase in back pressure of conventionally coated GPFs (about 60%).

[0108] In another example, the 2.0 L GTDI engine was equipped with different GPFs and tested separately using the FTP75 cycle. Figure 22 The filtration efficiency is shown, determined by the smoke particle concentration before and after filtration during Phase I of the FTP 75 cycle. The filter coated with nanoparticles using the disclosed technique exhibits higher filtration efficiency. The improvement increases with increasing particle load. An efficiency of 88% is achieved using the new technique with a load of approximately 1 g / L. In contrast, filters coated using conventional coating techniques show improved efficiency even at higher load levels of approximately 1.5 g / L. 3 This also shows a negative impact on efficiency. For example... Figure 23 As shown, for the coated GPF, the total particulate emissions at the exhaust tailpipe through the disclosed technology are significantly lower. Figure 24 Further, the back pressure at rated power predicted by measured permeability is shown, and the GPF coated with fine particles exhibits a lower or comparable back pressure compared to the conventional coated GPF.

[0109] While exemplary embodiments have been described above, this does not mean that these embodiments describe all possible forms of the present disclosure as disclosed in the various embodiments. Rather, the language used in this specification is descriptive rather than limiting, and it should be understood that various changes may be made without departing from the spirit and scope of the present disclosure as disclosed in the various embodiments. Furthermore, features of the various embodiments may be combined to form other embodiments of the present disclosure as disclosed in the various embodiments.

[0110] According to the present invention, an engine exhaust particulate filter is provided having a porous substrate having inert nanoparticles thereon having a filter volume concentration relative to the substrate ranging from 0.01 g / L to 60 g / L, a portion of the nanoparticles being arranged to form an anti-regenerative porous structure configured to trap particulates from the exhaust stream.

[0111] According to an embodiment, some of the structures are disposed within holes in the substrate.

[0112] According to an embodiment, the structure has a porosity of 70% or higher.

[0113] According to an embodiment, the nanoparticles include metals.

[0114] According to an embodiment, the nanoparticles comprise metal oxides.

[0115] According to an embodiment, some of the structures include catalyst nanoparticles.

[0116] According to an embodiment, the particulate filter of the engine exhaust has a greater particulate filtration efficiency than an engine exhaust particulate filter that is otherwise identical and does not contain nanoparticles.

[0117] According to an example, the engine exhaust particulate filter has a particulate filtration efficiency of 50% or higher for particles with a particle size of 1 µm or smaller.

[0118] According to an embodiment, the engine exhaust particulate filter has a back pressure at a certain flow rate, said back pressure being at most equal to 3.5 g / in. 3 The back pressure at a certain flow rate for engine exhaust particulate filters with or less coating load.

[0119] According to the present invention, an engine exhaust particulate filter is provided having a porous substrate having inert nanoparticles thereon in a filter volume concentration range of 0.01 g / L to 60 g / L relative to the substrate, wherein a portion of the inert nanoparticles configured to remain attached during substrate regeneration is effective for capturing particulates from the exhaust stream.

[0120] According to an embodiment, the nanoparticles include metals.

[0121] According to an embodiment, the nanoparticles comprise metal oxides.

[0122] According to an embodiment, the substrate also has catalytic nanoparticles thereon.

[0123] According to an embodiment, the particulate filter of the engine exhaust has a greater particulate filtration efficiency than an engine exhaust particulate filter that is otherwise identical and does not contain nanoparticles.

[0124] According to the embodiments, for particles with a particle size of 1 µm or smaller, the particle filter has a particle filtration efficiency of 50% or higher.

[0125] According to an embodiment, the engine exhaust particulate filter has a back pressure at a certain flow rate, said back pressure being at most equal to 3.5 g / in. 3 The back pressure at a certain flow rate for engine exhaust particulate filters with or less coating load.

[0126] According to the present invention, a method for preparing an engine exhaust particulate filter is provided, comprising: discharging nanoparticles in a carrier gas at a concentration in the range of 1 hr -1 Up to 2,000,000 hr-1 The spatial velocity flow passes through the porous substrate to deposit nanoparticles with a filter volume concentration ranging from 0.01 g / L to 60 g / L relative to the substrate, and to generate a regenerable porous structure with a porosity of 70% or higher.

[0127] According to an embodiment, the above method is further characterized in that, before the flow, a suspension of nanoparticles is atomized to generate atomized nanoparticles and the atomized nanoparticles are dried.

[0128] According to an embodiment, the nanoparticles include nanoparticle aggregates with a porosity of 50% or higher.

[0129] According to an embodiment, the method is further characterized in that the substrate is calcined after the flow.

Claims

1. An engine exhaust particulate filter, comprising: A porous substrate having inert nanoparticles, at a concentration ranging from 0.01 g / L to 60 g / L relative to the filter volume of the porous substrate, attached thereon. The inert nanoparticles do not have catalytic functionality. A portion of the inert nanoparticles is arranged to remain attached during the regeneration of the engine exhaust particulate filter and form an anti-regeneration porous structure configured to trap particulates from the exhaust stream. The back pressure of the engine exhaust particulate filter at a certain flow rate is at most equal to 3.5 g / in. 3 The back pressure of an engine exhaust particulate filter with a coating load of or less at the specified flow rate.

2. The engine exhaust particulate filter as claimed in claim 1, wherein some of the anti-regeneration porous structures are disposed within the pores of the porous substrate.

3. The engine exhaust particulate filter of claim 1, wherein the anti-regeneration porous structure has a porosity of 70% or higher.

4. The engine exhaust particulate filter of claim 1, wherein the porous substrate further comprises catalyst nanoparticles thereon.

5. The engine exhaust particulate filter of claim 1, wherein the inert nanoparticles comprise metal.

6. The engine exhaust particulate filter of claim 1, wherein the inert nanoparticles comprise silicon dioxide.

7. The engine exhaust particulate filter of claim 1, wherein the particulate filtration efficiency of the engine exhaust particulate filter is greater than that of an engine exhaust particulate filter that is otherwise identical and does not contain the inert nanoparticles.

8. The engine exhaust particulate filter of claim 1, wherein the engine exhaust particulate filter has a particulate filtration efficiency of 50% or higher for particles having a particle size of 1 µm or smaller.

9. An engine exhaust particulate filter, comprising: A porous substrate having inert nanoparticles attached thereon at a concentration ranging from 0.01 g / L to 60 g / L relative to the filter volume of the porous substrate. These inert nanoparticles do not have catalytic activity. A portion of these inert nanoparticles, configured to remain attached during regeneration of the engine exhaust particulate filter, is effective in capturing particulates from the exhaust stream. The back pressure of the engine exhaust particulate filter at a certain flow rate is at most equal to 3.5 g / in. 3 The back pressure of an engine exhaust particulate filter with a coating load of or less at the specified flow rate.

10. The engine exhaust particulate filter of claim 9, wherein the inert nanoparticles comprise metal.

11. The engine exhaust particulate filter of claim 9, wherein the inert nanoparticles comprise silicon dioxide.

12. The engine exhaust particulate filter of claim 9, wherein the porous substrate further comprises catalytic nanoparticles thereon.

13. The engine exhaust particulate filter of claim 9, wherein the particulate filtration efficiency of the engine exhaust particulate filter is greater than that of an engine exhaust particulate filter that is otherwise identical and does not contain the inert nanoparticles.

14. The engine exhaust particulate filter of claim 9, wherein the engine exhaust particulate filter has a particulate filtration efficiency of 50% or higher for particles having a particle size of 1 µm or smaller.

15. A method for preparing an engine exhaust particulate filter, comprising: To allow nanoparticles to travel in a carrier gas within a range of 1 hour -1 Up to 2,000,000 hr -1 The material flows through a porous substrate at a spatial velocity to deposit inert nanoparticles at a concentration ranging from 0.01 g / L to 60 g / L relative to the filter volume of the porous substrate, thereby generating a regeneration-resistant porous structure with a porosity of 70% or higher. The inert nanoparticles do not have catalytic activity, and the regeneration-resistant porous structure remains attached during the regeneration of the engine exhaust particulate filter. The back pressure of the engine exhaust particulate filter at a certain flow rate is at most equal to 3.5 g / in. 3 The back pressure of an engine exhaust particulate filter with a coating load of or less at the specified flow rate.

16. The method of claim 15, further comprising: The suspension of the inert nanoparticles is atomized before the flow to generate atomized inert nanoparticles and the atomized inert nanoparticles are dried.

17. The method of claim 15, wherein the inert nanoparticles comprise nanoparticle aggregates having a porosity of 50% or higher.

18. The method of claim 15, further comprising: The porous substrate is calcined after the flow.

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