Adsorbent material for removing nitrogen oxides from indoor or cabin air

Abstract

In certain embodiments, a system for removing pollutants such as nitrogen oxides from an internal air stream is disclosed that may include an adsorbent material including a zeolite and a base metal oxide.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority to U.S. Provisional Patent Application No. 63 / 104,347, filed on 22 October 2020, the disclosure of which is incorporated herein by reference in its entirety.

[0002] This disclosure relates to compositions, devices, and methods for air purification. More specifically, this disclosure relates to adsorbent substances, devices and systems, methods for producing the same, and methods for using them to remove gaseous pollutants (such as nitrogen oxides) from the air. [Background technology]

[0003] Traditional pollutant treatment systems and sorbents face numerous challenges, including improving long-term performance, increasing the efficiency of manufacturing processes, and reducing production costs. Generally, many sorbents are suitable for one type of adsorption application but are unable to remove other types of pollutants. Internal air purification, such as in buildings and vehicles, is one example where the removal of numerous types of pollutants, including nitrogen oxides, is critical. The need for devices, methods, and compositions that can effectively remove and retain pollutants, especially under ambient conditions, remains. [Overview of the Initiative] [Means for solving the problem]

[0004] Below are simplified summaries of various aspects of the Disclosure to provide a basic understanding of such aspects. These summaries are not an extensive overview of the Disclosure. Their intent is not to identify any important or definitive elements of the Disclosure, nor to describe any scope of any particular embodiment of the Disclosure or any scope of any claim. Their sole purpose is to present some of the concepts of the Disclosure in a simplified form as a preview of the more detailed descriptions that will be presented later.

[0005] In one embodiment of the present disclosure, a filter device suitable for removing and retaining NO2 from internal air at temperatures below 100°C comprises a substrate; and an adsorbent material, including zeolite and base metal oxides, coated on the substrate.

[0006] In one embodiment, the substrate is formed from non-metallic and non-ceramic materials. In another embodiment, the substrate is a foam substrate or a nonwoven polymer substrate. In yet another embodiment, the substrate is an aluminum substrate.

[0007] In one embodiment, the zeolite includes a zeolite selected from the group consisting of AEI, BEA, BEC, CHA, EMT, FAU, FER, MFI, and combinations thereof. In another embodiment, the zeolite includes a BEA zeolite.

[0008] In one embodiment, the base metal oxide includes zinc oxide, copper oxide, or a combination thereof.

[0009] In one embodiment, the internal air is recirculated air.

[0010] In one embodiment, the silica-to-alumina ratio (SAR) of the beta-zeolite is approximately 200 or higher.

[0011] In one embodiment, the silica-to-alumina ratio (SAR) of the beta-zeolite is approximately 300 or higher.

[0012] In one embodiment, the oxide is present in a loading amount of at least about 5% by mass relative to the total mass of the adsorbent material. In another embodiment, the oxide is present in a loading amount of about 5% to about 20% by mass.

[0013] In some embodiments, the adsorbent substance further comprises a binder. In some embodiments, the binder is a polymeric binder selected from the group consisting of polyethylene, polypropylene, polyolefin copolymer, polyisoprene, polybutadiene, polybutadiene copolymer, chlorinated rubber, nitrile rubber, polychloroprene, ethylene-propylene-diene elastomer, polystyrene, polyacrylate, polymethacrylate, polyacrylonitrile, poly(vinyl ester), poly(vinyl halogenate), polyamide, cellulose polymer, polyimide, acrylic resin, vinyl acrylic resin, styrene acrylic resin, polyvinyl alcohol, thermoplastic polyester, thermosetting polyester, poly(phenylene oxide), poly(phenylene sulfide), poly(tetrafluoroethylene), polyvinylidene fluoride, poly(vinyl fluoride), ethylene chlorotrifluoroethylene copolymer, polyamide, phenolic resin, polyurethane, acrylic / styrene acrylic copolymer latex, silicone polymer, and combinations thereof. In some embodiments, the binder comprises an alumina or zirconia binder.

[0014] In one embodiment, the adsorbent material further comprises one or more of silica gel, activated carbon, activated alumina, molecular sieves, resins, or catalytic materials.

[0015] In one embodiment, the filter device is incorporated into an internal air control system selected from building heating, ventilation and air conditioning (HVAC) systems, aircraft environmental control systems, ventilation systems for non-aircraft vehicles, and indoor air purification devices.

[0016] In one embodiment, the filter device, when in contact with air at 18-23°C with a moisture content of 1.5%, is suitable for cumulative NO2 removal exceeding 120, 350, 500, or 750 milligrams per gram of adsorbent material. Cumulative NO2 removal corresponds to the amount of NO2 removed over a period ranging from the initial removal efficiency of the adsorbent material to 20% of the initial removal efficiency.

[0017] In one embodiment, the filter device, when in contact with air at 18-23°C with a moisture content of 0.5%, is suitable for cumulative NO2 removal exceeding 30, 80, or 120 milligrams per gram of adsorbent material. Cumulative NO2 removal corresponds to the amount of NO2 removed over a period ranging from the initial removal efficiency of the adsorbent material to 20% of the initial removal efficiency.

[0018] In another embodiment of the present disclosure, substrates suitable for the removal and retention of NO2 from internal air at temperatures below 100°C include adsorbent materials, zeolites, and base metal oxides coated on at least one of their surfaces.

[0019] In one embodiment, the substrate is incorporated into an airflow conduit.

[0020] In another embodiment of the present disclosure, a method for removing and retaining NO2 from an internal airflow includes bringing the internal airflow into contact with an adsorbent material, including zeolite and base metal oxides, which is adapted to reduce the NO2 concentration of recirculated supply air.

[0021] In one embodiment, the supply air is maintained at a temperature of 10°C to 30°C.

[0022] In one embodiment, the desorption rate of NO2 adsorbed by the adsorbent substance is substantially zero at temperatures below 100°C.

[0023] In one embodiment, internal airflow is maintained or generated by a building's heating, ventilation, and air conditioning (HVAC) system, an aircraft's environmental control system, a ventilation system for a vehicle other than an aircraft, or an indoor air purification device.

[0024] In another embodiment of the present disclosure, an air purification system for removing and retaining NO2 from internal air comprises a substrate; and an adsorbent material coated on the substrate, comprising a beta-zeolite impregnated with a base metal oxide.

[0025] In another embodiment of the present disclosure, a method for forming a filter device suitable for removing and retaining NO2 from internal air includes: forming a zeolite composite material using a base metal precursor; calcining the composite material to form particles containing a base metal oxide formed from the zeolite and the base metal precursor; forming a slurry containing the particles and a binder; and coating the slurry onto a substrate to form a filter device.

[0026] In one embodiment, the composite is formed by the drop-dropping impregnation of a zeolite solution with a base metal precursor.

[0027] In one embodiment, the base metal precursor comprises one or more zinc acetate or copper acetate.

[0028] As used herein, the terms “adsorbent” and “adsorbent material” refer to materials capable of adhering gas molecules, ions, or other species within their structure (e.g., removal of CO2 from air). Specific materials include, but are not limited to, clay, metal-organic structures, activated alumina, silica gel, activated carbon, molecular sieve carbon, zeolites (e.g., molecular sieve zeolite), polymers, resins, and any of these components or others having gas adsorbent materials supported thereon (e.g., various embodiments of the sorbent media described herein). Some adsorbent materials may preferentially or selectively adhere to specific species.

[0029] As used herein, the term “adsorption capacity” refers to the working capacity of an adsorbent substance to adsorb a certain amount of chemical species under specific operating conditions (e.g., temperature and pressure). When the unit of adsorption capacity is given in mg / g, it corresponds to milligrams of adsorbed gas per gram of sorbent medium.

[0030] Furthermore, as used herein, the term “particle” refers to an aggregate of discrete parts, each having a maximum dimension in the range of 0.1 μm to 50 mm. The morphology of the particles may be crystalline, semi-crystalline, or amorphous. The size range disclosed herein may be mean / average or median size unless otherwise specified. It should also be noted that the particles do not have to be spherical, but may be in the form of cubes, cylinders, disks, or any other suitable shape recognized by those skilled in the art. “Powder” and “granules” may be the terms used for the type of particles.

[0031] Furthermore, as used herein, the term “monolith” refers to a single, integrated block of a particular material. A single, integrated block may be, for example, a brick, a disc, or a rod, and may include channels for increasing gas flow / distribution. In some embodiments, multiple monoliths may be arranged together to form a desired shape. In some embodiments, the monoliths may have a honeycomb shape with multiple parallel channels, each having a square, hexagon, or other shape.

[0032] Furthermore, as used herein, the term “dispersant” refers to a compound that helps maintain solid particles in a suspended state in a fluid medium and inhibits or reduces particle aggregation or sedimentation in the fluid medium.

[0033] Furthermore, as used herein, the term “binder” means, when included in a coating, layer, or film (e.g., a wash-coated coating, layer, or film on a substrate), a material that is homogeneously or semi-homogeneously distributed within the coating, layer, or film, promoting adhesion to the surface on which the coating, layer, or film is formed, and facilitating aggregation between the surface and the coating, layer, or film.

[0034] Furthermore, as used herein, the terms “flow” or “stream” broadly refer to any fluid gas, which may include solids (e.g., particulate matter), liquids (e.g., vapors), and / or gaseous mixtures.

[0035] Furthermore, as used herein, the terms “volatile organic compounds” and “VOC” refer to organic chemical molecules that have a high vapor pressure at room temperature. Such chemical molecules have low boiling points, and many of them evaporate and / or sublimate at room temperature, thereby migrating from the liquid or solid phase to the gas phase. Common VOCs include, but are not limited to, formaldehyde, benzene, toluene, xylene, ethylbenzene, styrene, propane, hexane, cyclohexane, limonene, pinene, acetaldehyde, hexaldehyde, ethyl acetate, and butanol.

[0036] Furthermore, as used herein, the terms “unpurified air” or “unpurified airflow” refer to any flow containing one or more contaminants at concentrations or levels above those deemed hazardous, which are considered to have adverse effects on human health (including short-term and / or long-term effects), and / or adverse effects on the operation of equipment. For example, in one embodiment, a flow containing formaldehyde at a concentration exceeding 0.5 parts per million parts of airflow, calculated as an 8-hour time-weighted average concentration in accordance with the “limit level” standards set by the Labor Safety and Health Administration, is an unpurified airflow. In another embodiment, a flow containing formaldehyde at a concentration exceeding 0.08 parts per million parts of airflow, calculated as an 8-hour time-weighted average concentration in accordance with Chinese national standards, is an unpurified airflow. Unpurified air may contain, but is not limited to, formaldehyde, ozone, carbon monoxide (CO), VOCs, methyl bromide, water, amine-containing compounds (e.g., ammonia), sulfur oxides, hydrogen sulfide, and nitrogen oxides.

[0037] Furthermore, as used herein, the terms “purified air” or “purified airflow” refer to any flow that is considered an unpurified airflow and contains one or more contaminants at concentrations or concentrations lower than those of the other contaminants.

[0038] Furthermore, as used herein, the term “substrate” refers to a material on which the catalyst is placed or on which it is placed (e.g., metals, metalloids and metalloid oxides, metal oxides, polymers, ceramics, paper, pulp / semipulp products, etc.). In some embodiments, the substrate may be in the form of a solid surface having a wash coat containing a plurality of catalyst particles and / or adsorbent particles. The wash coat may be formed by preparing a slurry containing a specified solid content (e.g., 30-50% by mass) of catalyst particles and / or adsorbent particles, which is then coated onto the substrate and dried to give a wash coat layer. In some embodiments, the substrate may be porous, and the wash coat may be deposited on the outside and / or inside of the pores.

[0039] Furthermore, as used herein, the term "nitrogen oxide" refers to compounds containing nitrogen and oxygen, including but not limited to nitric oxide, nitrogen dioxide, dinitrogen monoxide, nitrosyl azide, ozatetrazole, dinitrogen trioxide, dinitrogen tetroxide, dinitrogen pentoxide, trinitramide, nitrito, nitrate, nitronium, nitrosonium, peroxonitrito, or combinations thereof.

[0040] Furthermore, as used herein, the term “approximately” is used in relation to the quantity being measured and refers to the normal variation of the measured quantity as expected by a person skilled in the art who performs the measurement and is trained to a level of attention commensurate with the purpose of the measurement and the precision of the measuring equipment. For example, when “approximately” modifies a value, it may be interpreted as meaning that the value may vary by ±1%.

[0041] When considered herein, surface area is determined by the Brunauer-Emmett-Teller (BET) method according to DIN ISO 9277:2003-05 (a revised version of DIN 66131), and is referred to as "BET surface area." Specific surface area is determined by multipoint BET measurements in the relative pressure range of 0.05 to 0.3 p / p0.

[0042] This disclosure is illustrated as an example in the accompanying drawings, but is not intended to be limiting. [Brief explanation of the drawing]

[0043] [Figure 1] This figure shows an illustrative air treatment system according to an embodiment of the present disclosure. [Figure 2] Figure 2A shows a cross-section of an exemplary substrate having a coating of an adsorbent material formed thereon according to an embodiment of the present disclosure. Figure 2B shows a cross-section of the coating of an adsorbent material formed on the surface of the substrate according to an embodiment of the present disclosure. [Figure 3] This is a flow diagram illustrating a method for forming a filter device suitable for removing and retaining NO2 from internal air according to embodiments of the present disclosure. [Figure 4] This graph shows the removal of NO2 per unit mass of the adsorbent substance in the embodiment of the present disclosure. [Figure 5] This graph shows the initial NO2 removal rate for an example according to the embodiments of this disclosure. [Modes for carrying out the invention]

[0044] Embodiments described herein relate to adsorbent materials and systems incorporating them for removing contaminants from internal air. More specifically, the adsorbent materials may be incorporated into indoor air, cabin air (e.g., aircraft cabin air), and vehicle ventilation systems, which may be designed to remove nitrogen oxides, as well as other toxic chemical contaminants, such as formaldehyde, pentanoic acid, acetaldehyde, toluene, ozone, carbon monoxide, sulfur dioxide, amines (including ammonia), sulfur compounds (including thiols), chlorinated hydrocarbons, and other alkaline or acidic chemicals. The adsorbent materials may include, for example, an adsorbent physically blended with a catalyst in one or more layers of a washcoat, or an adsorbent present in a particular layer of a washcoat. The adsorbent materials may be capable of adsorbing and retaining (i.e., substantially zero desorption) contaminants such as nitrogen oxides (e.g., NO2) at temperatures below 100°C (e.g., 30–50°C).

[0045] Embodiments of the present disclosure can be used, for example, to reduce the NO2 content of internal air supplied to buildings, aircraft, or non-aircraft vehicles, or to be treated inside such vehicles. By blending adsorbents such as zeolites (e.g., dealuminized Y, beta with a high silica-to-alumina ratio (SAR), ZSM, etc.) with base metal oxides (e.g., one or more of copper oxide or zinc oxide), it is advantageous to capture compounds such as nitrogen oxides under ambient conditions and retain nitrogen oxides under ambient conditions, for example, at temperatures up to 100°C.

[0046] Figure 1 shows an illustrative air treatment system 100 according to an embodiment of the present disclosure. The system 100 includes a filter unit 104, which may be part of or external to an internal air control system 106, such as a building heating, ventilation and air conditioning (HVAC) system, and an aircraft ECS, or a non-aircraft ventilation system. As shown in Figure 1, the filter unit 104 and the internal air control system 106 are fluidly coupled to each other and to the internal space 102 so as to establish a recirculation airflow path 108. When various contaminants such as nitrogen oxides and odors accumulate in the internal space 102, the internal air may be recirculated through the filter unit 104 to adsorb the contaminants using a filter device, as described herein. The purified air then passes through the internal air control system 106, which may be further filtered (for example to remove dust and other particulate matter), heated or cooled, and then returned to the internal space 102 for recirculation. In some embodiments, the internal air control system 106 may include an outward airflow 110 and an inward airflow 112 that are filtered and then enter the internal space 102. In some embodiments, the filter unit 104 and the internal air control system 106 may be located within the internal space 102, for example, in the form of an indoor (e.g., portable) air purifier.

[0047] The embodiments of the airflow system 100 are merely illustrative, and it should be understood that embodiments of the adsorbent materials and filter devices described herein may be incorporated into other systems for air treatment, such as humidification / dehumidification systems, odor removal systems, VOC removal systems, positive electrode air treatment systems in automotive fuel cell systems, industrial systems, and other systems.

[0048] Figures 2A and 2B show cross-sections of a coated substrate 200 formed according to embodiments of the present disclosure. The coated substrate 200 includes a substrate 210 (e.g., a filter body), and a honeycomb filter configuration is illustrated, through which air passages 215 are formed. It should be understood that the honeycomb filter is merely illustrative and that other filter configurations may be used. The coated substrate 200 further includes an adsorbent material 220 coated on the inner wall of the substrate 210. In some embodiments, one or more additional layers of adsorbent material may be included on top of the adsorbent material 220. In some embodiments, the adsorbent material 220 may be in a laminated configuration, with at least one layer containing a different adsorbent material.

[0049] In some embodiments, the substrate may be in the form of a interconnected foam, honeycomb, or nonwoven polymer substrate. In some embodiments, the material of the substrate may be ceramic (e.g., porous ceramic), metal, polymer foam, plastic, paper, fibrous (e.g., polymer fiber), or a combination thereof. For example, in some embodiments, the substrate may be formed from polyurethane fibers or polyurethane foam. In some embodiments, the substrate may be a metal-integrated substrate, a ceramic-integrated substrate, a paper substrate, a polymer substrate, or a ceramic fiber-integrated substrate. In some embodiments, the substrate may be formed from non-metallic and non-ceramic materials. In other embodiments, the substrate is an aluminum substrate. In some embodiments, the substrate may be an HVAC duct, an air filter, or a louver surface. In some embodiments, the substrate may be a portable air filter, or a filter installed in a vehicle, such as an automobile, rail vehicle, seaplane, aircraft, or spacecraft.

[0050] In some embodiments, the substrate is selected from the group consisting of foams, integrated materials, nonwoven fabrics, woven fabrics, sheets, paper, twisted helices, ribbons, extruded structured media, wound structured media, folded structured media, pleated structured media, corrugated structured media, injected structured media, bonded structured media, and combinations thereof.

[0051] In one embodiment, the substrate is an extrusion medium. In some embodiments, the extrusion medium is a honeycomb. The honeycomb may be any geometric shape, including but not limited to circles, cylinders, and squares. Furthermore, the cells of the honeycomb substrate may be any geometric shape.

[0052] In one embodiment, the substrate is a foam. In some embodiments, the foam has more than about 10 pores per inch. In some embodiments, the foam has more than about 20 pores per inch. In some embodiments, the foam has between about 15 and about 40 pores per inch. In some embodiments, the foam is polyurethane. In some embodiments, the foam is a mesh polyurethane. In some embodiments, the polyurethane is polyether or polyester. In some embodiments, the substrate is a nonwoven fabric.

[0053] In some embodiments, the substrate is a plastic. In some embodiments, the substrate is a thermoplastic polyolefin. In some embodiments, the substrate is a thermoplastic polyolefin containing glass or mineral fillers. In some embodiments, the substrate is a plastic selected from the group consisting of polypropylene, nylon-6, nylon-6,6, aromatic nylon, polysulfone, polyethersulfone, polybutylene terephthalate, polyphthalamide, polyoxymethylene, polycarbonate, polyvinyl chloride, polyester, and polyurethane.

[0054] In some embodiments, the adsorbent material comprises a zeolite and a base metal oxide. In some embodiments, the zeolite may be an aluminosilicate material or a silica-aluminum phosphate material. The zeolite can be identified by a three-letter code designated by the International Zeolite Association. In some embodiments, the zeolite may include, for example, AEI, AFT, AFX, BEA, BEC, CHA, DDR, EMT, ERI, EUO, FAU, FER, GME, HEU, KFI, LEV, LTA, LTL, MAZ, MEL, MFI, MFS, MOR, MTN, MTT, MTW, MWW, NES, OFF, PAU, RHO, SFW, TON, UFI, or a combination thereof. In some embodiments, the zeolite may include, for example, zeolite X, zeolite Y, ultrastable zeolite Y, ZSM-5 zeolite, ofleite, beta zeolite, ferrieite, faujasite, rhodochrosite, mordenite, clinobtyrolite, silicolite, or a combination thereof. In some embodiments, the zeolite is a beta zeolite containing a high silica-to-alumina ratio.

[0055] In one embodiment, the zeolite includes a zeolite selected from the group consisting of AEI, BEA, BEC, CHA, EMT, FAU, FER, MFI, and combinations thereof. In another embodiment, the zeolite includes a BEA zeolite.

[0056] In some embodiments, the zeolite includes micropores and mesopores. Micropores correspond to pores having a width of less than 20 Å. In some embodiments, the pores have a width of 2.0 Å to 6.7 Å, or 4.0 Å to 6.5 Å. In some embodiments, micropores account for 70%, 80%, or 90% or more of the total pore volume of the zeolite.

[0057] In some embodiments, the silica-to-alumina ratio of the zeolite is greater than about 100, greater than about 150, greater than about 200, or greater than about 250.

[0058] In some embodiments, the zeolite is in the form of zeolite particles. The zeolite particles may be characterized by an average d90 particle size of about 5 to 50 micrometers, about 10 to 25 micrometers, or about 15 to 20 micrometers.

[0059] In one embodiment, the total amount of zeolite may be about 1% by mass, about 5% by mass, about 10% by mass, about 15% by mass, about 20% by mass, about 25% by mass, about 30% by mass, about 35% by mass, about 40% by mass, about 45% by mass, about 50% by mass, about 55% by mass, about 60% by mass, about 65% by mass, about 70% by mass, about 75% by mass, or within any defined range (including both ends) between these points.

[0060] In one embodiment, the base metal oxide may include, for example, one or more zinc oxide or copper oxide. The total amount of base metal oxide may be about 1% by mass, about 5% by mass, about 10% by mass, about 15% by mass, about 20% by mass, about 25% by mass, about 30% by mass, about 35% by mass, about 40% by mass, about 45% by mass, about 50% by mass, about 55% by mass, about 60% by mass, about 65% by mass, about 70% by mass, about 75% by mass, or any defined range (including both ends) between these points, based on the total mass of the adsorbent material.

[0061] In one embodiment, the adsorbent material includes, for example, a combination of adsorbent materials such as one or more silica gel, activated carbon, activated alumina, molecular sieves, resins, or zeolite particles mixed with catalytic materials. In one embodiment, the activated carbon may be synthetic activated carbon, or based on or derived from wood, carbonized peat, coconut shells, lignite, petroleum pitch, petroleum coke, coal tar pitch, fruit pitch, nuts, seashells, sawdust, wood flour, synthetic polymers, natural polymers, and combinations thereof. Each of these additional components, such as activated carbon or catalytic material, may be present in amounts of about 1% by mass, about 2% by mass, about 3% by mass, about 4% by mass, about 5% by mass, about 6% by mass, about 7% by mass, about 8% by mass, about 9% by mass, about 10% by mass, about 11% by mass, about 12% by mass, about 13% by mass, about 14% by mass, about 15% by mass, about 16% by mass, about 17% by mass, about 18% by mass, about 19% by mass, about 20% by mass, or within any defined range (including the endpoints) between any of these points.

[0062] In some embodiments, the catalyst material may include one or more of manganese, platinum, palladium, or cerium. In some embodiments, the catalyst material includes platinum particles having a diameter greater than 2 nanometers. In some embodiments, the catalyst material includes platinum-modified alumina. In some embodiments, the catalyst material includes potassium-modified manganese oxide. In some embodiments, the catalyst material may include a catalyst metal oxide. The catalyst metal oxide may include one or more of manganese oxide, cobalt oxide, molybdenum oxide, chromium oxide, copper oxide, or cerium oxide. In some embodiments, the metal oxide may be a rare earth metal oxide.

[0063] In some embodiments, the catalyst metal oxide is manganese oxide. In some embodiments, the manganese oxide is amorphous or at least partially amorphous. In some embodiments, the manganese oxide is semicrystalline. In some embodiments, the manganese oxide may include cryptomelene, barnesite, vernadite, manganese oxide polymorph I, incompletely crystalline cryptomelene, amorphous manganese oxide, its polymorphs, amorphous manganese oxide, or mixtures thereof.

[0064] In an embodiment, the adsorbent material may be formulated as a slurry and wash-coated onto a substrate. In an embodiment, the loading (addition) of the catalyst adsorbent material onto the substrate is about 0.5 g / in relative to the volume of the substrate 3 to about 4 g / in 3 It may be in the range of . In an embodiment, the catalyst adsorbent material may be coated onto a substrate to form a single adsorbent layer or a plurality of adsorbent layers on a solid substrate. When a plurality of adsorbent layers are coated onto the solid substrate, the layers may vary in their composition, or alternatively, all of the adsorbent layers may have the same composition.

[0065] In an embodiment, the adsorbent material is formed from porous particles in powder form. In an embodiment, the average size of the particles / powder ranges from about 1.0 μm to about 100 μm. In an embodiment, the average size ranges from about 5.0 μm to about 50 μm.

[0066] In an embodiment, the BET surface area of the adsorbent material is about 20 m 2 / g to about 5,000 m 2 / g or more. In an embodiment, the BET surface area of the adsorbent is from about 20 m 2 / g to about 4,000 m 2 / g, from about 20 m 2 / g to about 3,000 m 2 / g, from about 20 m 2 / g to about 2,500 m 2 / g, from about 20 m 2 / g to about 2,000 m 2 / g, from about 20 m 2 / g to about 1,000 m 2 / g, from about 20 m 2 / g to about 500 m 2 / g, from about 20 m 2 / g to about 300 m 2 / g, from about 100 m 2 / g to about 5,000 m 2 / g, from about 100 m 2 / g to about 4,000 m 2 / g, from about 100 m 2 / g~approximately 3,000m 2 / g, approximately 100m 2 / g~approximately 2,500m 2 / g, approximately 100m 2 / g~approximately 2,000m 2 / g, approximately 100m 2 / g~approximately 1,000m 2 / g, approximately 100m 2 / g~approximately 500m 2 / g, approximately 100m 2 / g~approximately 300m 2 / g, approximately 300m 2 / g~approximately 5,000m 2 / g, approximately 300m 2 / g~approximately 4,000m 2 / g, approximately 300m 2 / g~approximately 3,000m 2 / g, approximately 300m 2 / g~approximately 2,500m 2 / g, approximately 300m 2 / g~approximately 2,000m 2 / g, approximately 300m 2 / g~approximately 1,000m 2 / g, approximately 300m 2 / g~approximately 500m 2 / g, approximately 750m 2 / g~approximately 5,000m 2 / g, approximately 750m 2 / g~approximately 4,000m 2 / g, approximately 750m 2 / g~approximately 3,000m 2 / g, approximately 750m 2 / g~approximately 2,500m 2 / g, approximately 750m 2 / g~approximately 2,000m 2 / g, approximately 750m 2 / g~approximately 1,000m 2 / g, approximately 1,200m 2 / g~approximately 5,000m 2 / g, approximately 1,200m 2 / g~approximately 4,000m 2 / g, approximately 1,200m 2 / g~approximately 3,000m 2 / g, approximately 1,200m 2 / g~approximately 2,500m 2 / g, approx. 1,500m 2 / g ~ approx. 5,000m 2 / g, approx. 1,750m 2 / g ~ approx. 5,000m 2 / g, approx. 2,000m 2 / g ~ approx. 5,000m 2 / g, approx. 2,500m 2 / g ~ approx. 5,000m 2 / g, approx. 3,000m 2 / g ~ approx. 5,000m 2 / g, approx. 3,500m 2 / g ~ approx. 5,000m 2 / g, or approximately 4,000m 2 / g ~ approx. 5,000m 2 It is / g.

[0067] To increase the capacity of the porous support used in embodiments of this disclosure, the adsorbent can be activated. Activation may involve subjecting the adsorbent (e.g., particles) to a variety of conditions, including but not limited to room temperature, vacuum, an inert gas flow, or any combination thereof, for a time sufficient to activate the adsorbent. In some embodiments, the adsorbent may be activated by calcination.

[0068] In some embodiments, the slurry may further contain a binder that can help promote adhesion of the adsorbent material to the substrate. In some embodiments, the binder can be crosslinked by itself to improve adhesion. The presence of a binder can enhance the integrity of the hydrocarbon adsorbent, improve its adhesion to the substrate, and provide structural stability under the vibration conditions encountered in automobiles.

[0069] The binder may contain additives to improve water resistance and adhesion. Typical binders used in slurry formulations include, but are not limited to, organic polymers; sols of alumina, silica, or zirconia; inorganic salts, organic salts, and / or hydrolysis products of aluminum, silica, or zirconium; hydroxides of aluminum, silica, or zirconium; organic silicates hydrolyzable to silica; and mixtures thereof. In some embodiments, the binder includes a zirconium salt (e.g., zirconium acetate). In some embodiments, the binder is an organic polymer. The organic polymer may be a thermosetting or thermoplastic polymer and may be a plastic or elastomer. The binder may be, for example, acrylic / styrene copolymer latex, styrene-butadiene copolymer latex, polyurethane, or any mixture thereof. In some embodiments, the polymeric binder includes acrylic / styrene acrylic copolymer latex such as hydrophobic styrene acrylic emulsion. In some embodiments, the binder is selected from acrylic / styrene copolymer latex, styrene-butadiene copolymer latex, polyurethane, and mixtures thereof. In some embodiments, the binder comprises an acrylic / styrene copolymer latex and a polyurethane dispersion. The polymeric binder may also contain suitable stabilizers and anti-aging agents known in the art. In some embodiments, the binder is a thermosetting elastomer polymer introduced into the slurry (e.g., an aqueous slurry) as a latex before coating the slurry onto the substrate.

[0070] Examples of suitable polymeric binders may include, but are not limited to, polyethylene, polypropylene, polyolefin copolymers, polyisoprene, polybutadiene, polybutadiene copolymers, chlorinated rubber, nitrile rubber, polychloroprene, ethylene-propylene-diene elastomer, polystyrene, polyacrylate, polymethacrylate, polyacrylonitrile, poly(vinyl ester), poly(vinyl halogenate), polyamide, cellulosic polymers, polyimide, acrylic resins, vinyl acrylic resins, styrene acrylic resins, polyvinyl alcohol, thermoplastic polyesters, thermosetting polyesters, poly(phenylene oxide), poly(phenylene sulfide), fluorinated polymers, e.g., poly(tetrafluoroethylene), polyvinylidene fluoride, poly(vinyl fluoride), and chloro / fluoro copolymers, e.g., ethylene chlorotrifluoroethylene copolymer, polyamide, phenolic resin, polyurethane, acrylic / styrene acrylic copolymer latex, and silicone polymers.

[0071] In one embodiment, the binder or a mixture of binders is present in an amount of about 5% to about 50% by mass relative to the total mass of the hydrocarbon adsorbent when dried and deposited on the substrate. In another embodiment, the polymeric binder is present in an amount of about 5% to about 30% by mass, about 10% to about 30% by mass, about 15% to about 30% by mass, about 5% to about 25% by mass, about 5% to about 20% by mass, about 5% to about 15% by mass, about 10% to about 20% by mass, or about 15% to about 20% by mass.

[0072] Figure 3 is a flow diagram illustrating a method 300 for forming a filter device adapted for the removal and retention of NO2 from internal air according to embodiments of the present disclosure. Method 300 begins in block 302, in which a composite material of zeolite and base metal precursor is formed by dissolving the materials, for example, in an aqueous solution. In one embodiment, block 302 is a solution drop-in impregnation process for impregnating the zeolite with the base metal precursor. In one embodiment, the base metal precursor comprises one or more zinc acetates or copper acetates.

[0073] In block 304, the composite material is calcined to form particles containing zeolite and base metal oxides formed from base metal precursors.

[0074] In block 306, the slurry is formed by mixing calcined particles with a binder, for example, in an aqueous carrier.

[0075] In some embodiments, the slurry may contain additional additives, such as thickeners, dispersants, surfactants, biocides, antioxidants, etc., which may be added to the slurry and subsequently form adsorbent substances on the substrate. Thickeners, for example, enable the achievement of a sufficient amount of coating on a substrate with a relatively small surface area. Thickeners can also contribute in a secondary role by increasing slurry stability through steric hindrance of dispersed particles. They can also assist in the bonding of the coating surface. Exemplary thickeners include xanthan gum thickeners or carboxymethylcellulose thickeners. Kelzan® CC (available from CP Kelco) is one such exemplary xanthan gum thickener.

[0076] In some embodiments, the slurry contains a dispersant. The dispersant may be anionic, cationic, or nonionic and may be used in an amount of about 0.1% to about 10% by mass relative to the mass of the hydrocarbon adsorbent. Suitable dispersants include, but are not limited to, polyacrylates, alkoxylates, carboxylates, phosphate esters, sulfonates, taurates, sulfosuccinates, stearates, laureates, amines, amides, imidazolines, sodium dodecylbenzenesulfonate, sodium dioctylsulfosuccinate, and mixtures thereof. In some embodiments, the dispersant is a low molecular weight polyacrylic acid in which many of the acid's protons are replaced with sodium. In some embodiments, the dispersant is an ammonium polycarboxylate salt. In some embodiments, the dispersant contains one or more anionic surfactants, cationic surfactants, amphoteric surfactants, or nonionic surfactants. In some embodiments, the dispersant is a nonionic acrylic copolymer. In some embodiments, the dispersant is a hydrophobic copolymer pigment dispersant. An example dispersant is Tamol® 165A (a trademark of Dow Chemical). Increasing the slurry pH or adding an anionic dispersant alone can provide sufficient stabilization to the slurry mixture, but improved results can be obtained when both pH increases and an anionic dispersant are used. In some embodiments, the dispersant is a nonionic surfactant such as Surfynol® 420 (Air Products and Chemicals, Inc). In some embodiments, the dispersant is an acrylic block copolymer such as Dispex® Ultra PX 4575 (BASF).

[0077] In one embodiment, the slurry further comprises an oxidizing agent that can improve the efficiency of nitrogen oxide removal. The oxidizing agent may be selected from nitric acid, hypochlorite, persulfate, peroxide, permanganate, or chlorate.

[0078] In one embodiment, the slurry further comprises an alkaline component, for example, a hydroxide, ammonia or carbonate that can improve slurry stabilization. In one embodiment, the pH of the slurry may be adjusted between 2 and 12, or between 4 and 10.

[0079] At block 308, the slurry is deposited on a substrate such as a filter body and dried to form a filter device. In one embodiment, drying is performed at a temperature of from about 80°C to about 250°C.

[0080] The substrate may comprise a material selected from polymeric foams, polymeric fibers, nonwoven fabrics, ceramics or pulp products (e.g., paper). In one embodiment, the substrate comprises a polymeric foam including polyurethane. In one embodiment, the substrate is in the form of a honeycomb. In one embodiment, the substrate is a metal (e.g., aluminum).

[0081] In some embodiments, the slurry is washcoated onto the substrate, and the loading amount of the hydrocarbon adsorbent on the substrate is 1g / in 3 or less. In some embodiments, the loading amount is 0.5g / in 3 to 1g / in 3 , or 0.75g / in 3 to 1g / in 3 . In some embodiments, the loading amount is more than 1g / in 3 . In some embodiments, the loading amount is 1g / in 3 to 1.25g / in 3 , 1.25g / in 3 to 1.5g / in 3 , 1.5g / in 3 to 1.75g / in 3 , or 1.75g / in 3 to 2g / in 3 .

[0082] In some embodiments, the coating thickness of the adsorbent material after drying is more than 50 micrometers and less than about 500 micrometers, less than 400 micrometers, less than 300 micrometers, less than 200 micrometers, or less than 100 micrometers.

[0083] It is noted that the blocks of method 300 are not limiting, and in some embodiments, some or all of the blocks of each method may be performed. In some embodiments, one or more of the blocks may be performed substantially simultaneously. Some blocks may be omitted entirely or repeated.

Examples

[0084] Illustrative Examples The following examples are set forth to aid in understanding the present disclosure, and it should not be construed that they specifically limit the embodiments described and claimed herein. Such variations of embodiments, including all equivalent substitutions known at this time or later developed within the understanding of those skilled in the art, as well as changes in formulation or minor changes in experimental design, should be considered to be within the scope of the embodiments incorporated herein.

[0085] [Example 1] 18.2 g of copper acetate was dissolved in 100 mL of water. Then, 63 g of beta zeolite, SAR-300, was impregnated into the metal salt solution by a dropping method. After impregnation, the material was calcined at 550°C for 5 hours. Then, 49.7 g of the calcined material was added to 75 mL of water to form a slurry. The slurry was ground such that the d90 was 6.2 μm. 4.7 g of a styrene acrylic binder was added, followed by mixing for 15 minutes. Then, the slurry was coated onto a 0.85” (d)×1” (h) aluminum honeycomb substrate to obtain 1.01 g / in 3 loading. Then, the coated monolith was dried at 90°C for 2 hours.

[0086] [Example 2] 75 g of copper nitrate was dissolved in 80 mL of water. Then, 190 g of beta-zeolite, SAR-300, was impregnated into the metal salt solution by the dropwise method. After impregnation, the material was calcined at 550°C for 5 hours. Next, 49.0 g of the calcined material was added to 75 mL of water to form a slurry. The slurry was ground until the d90 was 27 μm. 4.9 g of styrene-acrylic acid binder was added and then mixed for 15 minutes. Next, a 0.85"(d) x 1"(h) aluminum honeycomb substrate was coated with 1.00 g / in. 3 The load capacity was achieved. Next, the coated monolith was dried at 90°C for 2 hours.

[0087] [Example 3] 50.3 g of zinc acetate was dissolved in 120 mL of water. Then, 126 g of beta-zeolite, SAR-300, was impregnated into the metal salt solution by the dropwise method. After impregnation, the material was calcined at 550°C for 5 hours. Next, 47.9 g of the calcined material was added to 72 mL of water to form a slurry. The slurry was ground until the d90 was less than 20 μm. 4.9 g of styrene-acrylic binder was added and then mixed for 15 minutes. Next, it was coated onto a 0.85"(d) x 1"(h) aluminum honeycomb 230 cpsi substrate at a density of 0.99 g / in. 3 The load capacity was achieved. Next, the coated monolith was dried at 90°C for 2 hours.

[0088] [Example 4] 75 g of copper nitrate was dissolved in 80 ml of water. Then, 190 g of beta-zeolite, SAR-300, was impregnated into the metal salt solution by the dropwise method. After impregnation, the material was calcined at 550°C for 5 hours. Next, 49.0 g of the calcined material was added to 75 ml of water to form a slurry. The slurry was ground until the d90 was 27 μm. 4.9 g of styrene-acrylic binder was added and then mixed for 15 minutes. Next, it was coated onto a 0.85"(d) x 1"(h) aluminum honeycomb substrate at a density of 1.00 g / in. 3 The load capacity was achieved. Next, the coated monolith was dried at 90°C for 2 hours.

[0089] [Example 5] 45 g of copper nitrate trihydrate was dissolved in 25 mL of water. Then, 126 g of zeolite ZSM-5, SAR-280 was impregnated into the metal salt solution by the dropwise method. After impregnation, the material was calcined at 550°C for 5 hours. Next, 95.32 g of the calcined material was added to 95.1 mL of water to form a slurry. The slurry was ground until the d90 was less than 20 μm. 9.6 g of styrene-acrylic binder was added and then mixed for 15 minutes. Next, it was coated onto a 0.85”(d) x 1”(h) aluminum honeycomb 230 cpsi substrate at a concentration of 1.03 g / in. 3 The load capacity was achieved. Next, the coated monolith was dried at 90°C for 2 hours.

[0090] [Example 6] 45 g of copper nitrate trihydrate was dissolved in 25 mL of water. Then, 126 g of zeolite ZSM-5 and SAR-17 were impregnated into the metal salt solution by the dropwise method. After impregnation, the material was calcined at 550 °C for 5 hours. Next, 95 g of the calcined material was added to 95 mL of water to form a slurry. The slurry was ground until the d90 was less than 20 μm. 9.6 g of styrene-acrylic binder was added and then mixed for 15 minutes. Next, it was coated onto a 0.85”(d) x 1”(h) aluminum honeycomb substrate at 230 cpsi, with a density of 1.03 g / in. 3 The load capacity was achieved. Next, the coated monolith was dried at 90°C for 2 hours.

[0091] test Test conditions: An unpurified airflow (16.6 L / min) containing 2.5–3.5 ppm NO2 and 0.5 or 1.5% water in air at 18–23°C was directed through an aluminum honeycomb catalyst. The initial percentage of NO2 removed was calculated using the following formula: 1-([NO2 outlet concentration] / [NO2 inlet concentration]) x 100 The cumulative amount of NO2 removed is calculated as follows:

number

[0092] The cumulative amount of NO2 removed is reported as the point at which the removal rate decreases to 20%, and this is normalized to the amount of NO2 removed per gram of material.

[0093] Figure 4 is a graph showing the cumulative NO2 removal per unit mass of adsorbent material for various examples.

[0094] Figure 5 is a graph showing the initial NO2 removal rates for various examples. Examples 1-3 consistently demonstrate performance with initial NO2 removal rates exceeding 70% under 0.5% and 1.5% water conditions.

[0095] In the foregoing description, numerous specific details, such as certain materials, dimensions, and process parameters, are described to give a complete understanding of embodiments of the present disclosure. Certain features, structures, materials, or properties may be combined in any suitable manner in one or more embodiments. The terms “Example” or “Illustrative” are used herein to mean that they serve as examples, illustrations, or demonstrations. Any aspect or design described herein as “Example” or “Illustrative” is not necessarily construed as being preferable or advantageous to other aspects or designs. Rather, the use of the terms “Example” or “Illustrative” is intended to present a concept of a particular style. Where used herein, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless otherwise specified or evident from the context, “X includes A or B” is intended to mean any of the original inclusive substitutions; i.e., if X includes A; if X includes B; or if X includes both A and B, then “X includes A or B” is satisfied in any of the foregoing examples. Furthermore, in the context of describing the materials and methods discussed herein (particularly in the context of the following claims), the use of “a,” “an,” “the,” and similar indicating terms should be interpreted as covering both singular and plural, unless otherwise indicated herein or the context is clearly contradictory.

[0096] The descriptions of value ranges in this specification are intended merely as a means of convenience for referring individually to each distinct value within that range, unless otherwise specified herein, and each distinct value is incorporated into the specification as if it were described individually. All methods described herein may be performed in any suitable order, unless otherwise indicated herein or the context would otherwise be obviously inconsistent.

[0097] Throughout this specification, references to “one embodiment,” “a certain embodiment,” “one or more embodiments,” “embodiment,” or “several embodiments” mean that certain features, structures, materials, or properties described in relation to an embodiment are included in at least one embodiment of this disclosure. Therefore, occurrences of phrases such as “in one or more embodiments,” “in a certain embodiment,” “in one embodiment,” or “in an embodiment” in various places throughout this specification do not necessarily refer to the same embodiment of this disclosure. Furthermore, certain features, structures, materials, or properties may be combined in any suitable manner in one or more embodiments.

[0098] It should be understood that the above description is illustrative and not intended to be restrictive. Many other embodiments will become apparent to those skilled in the art by reading and understanding the above description. Accordingly, the scope of this disclosure should be determined by referring to the appended claims and together with the entire scope of equivalents to which such claims are granted. The use of any examples or illustrative language provided herein (e.g., “such as”) is intended merely to better illustrate the materials and methods and does not impose any limitation on their scope unless otherwise claimed. Nothing in this specification, nor any unclaimed element, should be construed as indicating that it is essential for the carrying out of the materials and methods of this disclosure.

[0099] While embodiments disclosed herein are described in relation to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the Disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and apparatus of the Disclosure without deviating from the spirit and scope of the Disclosure. Accordingly, the Disclosure includes modifications and variations that fall within the scope of the appended claims and their equivalents, and the above embodiments are intended to be presented for illustrative purposes only, not for limitation.

Claims

1. NO from internal air supplied to buildings, aircraft, or non-aircraft vehicles at temperatures below 100°C. ２ A filter device suitable for removal and retention of, Substrate; and The substrate is coated with an adsorbent substance containing zeolite and base metal oxides, A filter device wherein the zeolite includes BEA zeolite, the silica-to-alumina ratio (SAR) of the BEA zeolite is 200 or more, and the base metal oxide includes zinc oxide, copper oxide, or a combination thereof.

2. The filter device according to claim 1, wherein the substrate is formed from a material other than a metal material and a ceramic material.

3. The filter device according to claim 1, wherein the substrate is a foam substrate or a nonwoven polymer substrate.

4. The filter device according to claim 1, wherein the substrate is an aluminum substrate.

5. The filter device according to any one of claims 1 to 4, wherein the internal air is recirculated air.

6. The filter device according to any one of claims 1 to 5, wherein the silica-to-alumina ratio (SAR) is 300 or more.

7. The filter device according to any one of claims 1 to 6, wherein the base metal oxide is present in an amount of at least 5% by mass relative to the total mass of the adsorbent material.

8. The filter device according to any one of claims 1 to 7, wherein the base metal oxide is present in a load of 5% to 20% by mass.

9. The filter device according to any one of claims 1 to 8, wherein the adsorbent substance further comprises a binder.

10. The filter device according to claim 9, wherein the binder is a polymeric binder selected from the group consisting of polyethylene, polypropylene, polyolefin copolymer, polyisoprene, polybutadiene, polybutadiene copolymer, chlorinated rubber, nitrile rubber, polychloroprene, ethylene-propylene-diene elastomer, polystyrene, polyacrylate, polymethacrylate, polyacrylonitrile, poly(vinyl ester), poly(vinyl halogenate), polyamide, cellulose polymer, polyimide, acrylic resin, vinyl acrylic resin, styrene acrylic resin, polyvinyl alcohol, thermoplastic polyester, thermosetting polyester, poly(phenylene oxide), poly(phenylene sulfide), poly(tetrafluoroethylene), polyvinylidene fluoride, poly(vinyl fluoride), ethylene chlorotrifluoroethylene copolymer, polyamide, phenolic resin, polyurethane, acrylic / styrene acrylic copolymer latex, silicone polymer, and combinations thereof.

11. The filter device according to claim 9, wherein the binder comprises an alumina or zirconia binder.

12. The filter device according to any one of claims 1 to 11, wherein the adsorbent substance further comprises one or more of silica gel, activated carbon, activated alumina, molecular sieves, resins, or catalyst materials.

13. A filter device according to any one of claims 1 to 12, which is incorporated into an internal air control system selected from a building heating, ventilation and air conditioning (HVAC) system, an aircraft environmental control system, a ventilation system for a vehicle other than an aircraft, and an indoor air purification device.

14. NO from internal air supplied to a building, aircraft or vehicle other than an aircraft at a temperature of less than 100°C ２ A substrate suitable for removal and retention, comprising an adsorbent substance, zeolite, and base metal oxide coated on at least one of its surfaces, A substrate wherein the zeolite includes BEA zeolite, the silica-to-alumina ratio (SAR) of the BEA zeolite is 200 or more, and the base metal oxide includes zinc oxide, copper oxide, or a combination thereof.

15. The substrate according to claim 14, which is incorporated into an airflow conduit.

16. A substrate according to either claim 14 or claim 15, formed from a material other than a metal material or a ceramic material.

17. The substrate according to claim 14 or claim 15, wherein the substrate is a foamed substrate or a nonwoven polymer substrate.

18. The substrate according to claim 14 or claim 15, wherein the substrate is an aluminum substrate.

19. The substrate according to any one of claims 14 to 18, wherein the internal air is recirculated air.

20. The substrate according to any one of claims 14 to 19, wherein the ratio of silica to alumina (SAR) is 300 or more.

21. The substrate according to any one of claims 14 to 20, wherein the base metal oxide is present in an amount of at least 5% by mass relative to the total mass of the adsorbent substance.

22. The substrate according to any one of claims 14 to 21, wherein the base metal oxide is present in a load of 5% to 20% by mass.

23. The substrate according to any one of claims 14 to 22, wherein the adsorbent substance further comprises a binder.

24. The substrate according to claim 23, wherein the binder is a polymeric binder selected from the group consisting of polyethylene, polypropylene, polyolefin copolymer, polyisoprene, polybutadiene, polybutadiene copolymer, chlorinated rubber, nitrile rubber, polychloroprene, ethylene-propylene-diene elastomer, polystyrene, polyacrylate, polymethacrylate, polyacrylonitrile, poly(vinyl ester), poly(vinyl halogenate), polyamide, cellulose polymer, polyimide, acrylic resin, vinyl acrylic resin, styrene acrylic resin, polyvinyl alcohol, thermoplastic polyester, thermosetting polyester, poly(phenylene oxide), poly(phenylene sulfide), poly(tetrafluoroethylene), polyvinylidene fluoride, poly(vinyl fluoride), ethylene chlorotrifluoroethylene copolymer, polyamide, phenolic resin, polyurethane, acrylic / styrene acrylic copolymer latex, silicone polymer, and combinations thereof.

25. The substrate according to claim 23, wherein the binder comprises an alumina or zirconia binder.

26. The substrate according to any one of claims 14 to 25, wherein the adsorbent substance further comprises one or more of silica gel, activated carbon, activated alumina, molecular sieves, resins, or catalyst materials.

27. A substrate according to any one of claims 14 to 26, which is incorporated into an internal air control system selected from a building heating, ventilation and air conditioning (HVAC) system, an aircraft environmental control system, a non-aircraft vehicle ventilation system, and an indoor air purification device.

28. NO from internal airflow supplied to a building, aircraft or vehicle other than an aircraft ２ A method for removal and retention of, NO in recirculated intake air ２ This involves bringing an adsorbent material containing zeolite and base metal oxides, suitable for reducing concentration, into contact with the internal airflow, A method wherein the zeolite includes BEA zeolite, the silica-to-alumina ratio (SAR) of the BEA zeolite is 200 or more, and the base metal oxide includes zinc oxide, copper oxide, or a combination thereof.

29. The method according to claim 28, wherein the supply air is maintained at a temperature of 10°C to 30°C.

30. NO adsorbed by the aforementioned adsorbent substance ２ The method according to either claim 28 or claim 29, wherein the desorption rate is substantially zero at temperatures below 100°C.

31. The method according to any one of claims 28 to 30, wherein the internal airflow is maintained or generated by a building heating, ventilation and air conditioning (HVAC) system, an aircraft environmental control system, a ventilation system for a vehicle other than an aircraft, or an indoor air purification device.

32. The method according to any one of claims 28 to 31, wherein the adsorbent substance comprises the adsorbent substance described in any one of claims 1 to 15.

33. NO from internal air supplied to buildings, aircraft, or non-aircraft vehicles. ２ An air purification system for the removal and retention of, Substrate; and The substrate is coated with an adsorbent material containing a beta-zeolite impregnated with a base metal oxide, An air purification system in which the zeolite includes BEA zeolite, the silica-to-alumina ratio (SAR) of the BEA zeolite is 200 or more, and the base metal oxide includes zinc oxide, copper oxide, or a combination thereof.

34. The air purification system according to claim 33, wherein the substrate includes the substrate described in any one of claims 14 to 27.

35. NO from internal air supplied to buildings, aircraft, or non-aircraft vehicles. ２ A method for forming a filter device suitable for removal and retention of, Forming zeolite composite materials using base metal precursors; The composite material is calcined to form particles containing the zeolite and a base metal oxide formed from the base metal precursor; Forming a slurry containing the aforementioned particles and binder; and This includes forming the filter device by coating the slurry onto a substrate, A method wherein the zeolite includes BEA zeolite, the silica-to-alumina ratio (SAR) of the BEA zeolite is 200 or more, and the base metal oxide includes zinc oxide, copper oxide, or a combination thereof.

36. The method according to claim 35, wherein the composite is formed by the drop-drop impregnation of the zeolite with the base metal precursor.

37. The method according to claim 35 or claim 36, wherein the base metal precursor comprises one or more zinc acetate or copper acetate.

38. The method according to any one of claims 35 to 37, wherein the filter device includes the filter device described in any one of claims 1 to 13.

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