(19)
(11)EP 3 212 325 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
20.05.2020 Bulletin 2020/21

(21)Application number: 15795268.0

(22)Date of filing:  29.10.2015
(51)International Patent Classification (IPC): 
B01J 23/72(2006.01)
B01J 23/83(2006.01)
B01J 37/02(2006.01)
B01D 53/86(2006.01)
B60H 3/06(2006.01)
B01J 23/889(2006.01)
B01J 35/04(2006.01)
B01J 23/74(2006.01)
F24F 3/16(2006.01)
(86)International application number:
PCT/US2015/057976
(87)International publication number:
WO 2016/069856 (06.05.2016 Gazette  2016/18)

(54)

USE OF A VERBASE METAL CATALYST FOR TREATMENT OF OZONE AND VOLATILE ORGANIC COMPOUNDS PRESENT IN AIR SUPPLY

VERWENDUNG EINES BASISMETALLKATALYSATORS ZUM ABBAU VON IM ZUGEFÜHRTEN LUFT VORHANDENEN OZON UND FLÜCHTIGEN ORGANISCHEN VERBINDUNGEN

UTILISATION D'UN CATALYSEUR À BASE DE MÉTAUX COMMUNS POUR LE TRAITEMENT DE L'OZONE ET DE COMPOSÉS VOLATILS ORGANIQUES PRÉSENTS DANS UN COURANT D'AIR


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 30.10.2014 US 201462072738 P

(43)Date of publication of application:
06.09.2017 Bulletin 2017/36

(73)Proprietor: BASF Corporation
Florham Park, NJ 07932 (US)

(72)Inventors:
  • ROBINSON, David M.
    Princeton, NJ 08540 (US)
  • BUELOW, Mark T.
    Phillipsburg, NJ 08865 (US)
  • ALDEN, Laif R.
    Feasterville, PA 19053 (US)
  • DURILLA, Michael
    Howell, NJ 07731 (US)

(74)Representative: Lux, Berthold 
Maiwald Patentanwalts- und Rechtsanwaltsgesellschaft mbH Elisenhof Elisenstraße 3
80335 München
80335 München (DE)


(56)References cited: : 
EP-A1- 2 939 741
WO-A2-2011/019779
US-A- 4 585 625
US-A- 6 096 277
US-A1- 2010 266 473
US-B1- 6 517 899
WO-A1-2013/163536
DE-A1- 4 007 965
US-A- 5 204 309
US-A1- 2009 227 195
US-A1- 2010 310 441
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    TECHNICAL FIELD



    [0001] The present disclosure relates to methods that utilize catalysts for air purification. More particularly, the disclosure relates to the use of metal catalyst layers for removing ozone and volatile organic compounds from air supplies.

    BACKGROUND



    [0002] Atmospheric pollution is a concern of increasing importance as the levels of various atmospheric pollutants continue to increase. One primary pollutant of concern is ozone. Ozone is a molecule that consists of three oxygen atoms. Naturally-occurring ozone is formed miles above the earth in the stratosphere. This ozone layer is responsible for absorbing the majority of the sun's harmful ultraviolet radiation. Ground level ozone is produced by the reactions of nitrogen oxides and volatile organic compounds in the presence of direct sunlight. The main sources of nitrogen oxide and volatile organic compound gases are mobile emissions, industrial factories, electrical plants, chemical solvents, and gasoline vapors.

    [0003] Near the stratosphere, aircraft may be affected by various pollutants. For example, aircraft environmental control system ("ECS") supplies periodically contain high levels of ozone and volatile organic compound ("VOC") contaminants that are harmful/undesirable for passengers in the aircraft cabin or cockpit. Current aircraft cabin air catalyst converters contain high levels of precious metal including both palladium and platinum designed for ozone and VOC reduction respectively, which can be considerably costly to produce and maintain.

    [0004] At the ground level, pollution control is also performed by direct treatment of ozone and other contaminants at ground level utilizing vehicle heat exchangers. In these processes, ozone in the air that passes over catalyst-coated surfaces, such as radiators, convert ozone molecules into oxygen molecules. These processes capitalize on the large volume of air that passes through a vehicle's radiator.

    [0005] US 2010/0310441 A1 discloses catalysts that are capable of use at low temperatures (<80°C) to remove volatile organic compounds (VOCs) in an enclosed space.

    [0006] WO 2011/019779 A2 discloses methods and an apparatus for destroying ozone in an air stream.

    [0007] US 6,096,277 discloses a catalyst system useful at room temperature for the destruction of ozone, which is comprised of a washcoat of high surface area support containing Mn/Cu catalyst deposited on a macroporous carrier, such as a honeycomb monolith, optionally with the addition of noble metal (such as Pt) washcoat to remove carbon monoxide.

    [0008] US 2010/0266473 A1 discloses a method for oxidizing carbon monoxide (CO) and volatile organic compounds (VOCS) comprises contacting a gas containing water vapor and said CO and VOCs with a catalyst composition comprising at least one base metal promoter and at least one base metal catalyst supported on an oxide support material comprising one or more of alumina, silica, zirconia, ceria, and titania, wherein the VOCs comprise one or more of methyl acetate, methane, methyl bromide, benzene, methanol, methyl ethyl ketone, butane, and butene.

    [0009] US 5,204,309 A discloses a catalyst for neutralizing vapors and aerosols of organic compounds, carbon monoxide, and a variety of other oxidizable materials from an exhaust, which contains oxygen.

    [0010] US 2009/0227195 A1 discloses air treatment systems including an environmental control system, a mixer, an air distribution duct system, and one or more catalysts for treating the air in the aircraft cabin environment are provided.

    [0011] US 6,517,899 B1 discloses a composition and method for improving the adhesion properties of catalytic and adsorptive compositions to a substrate through the addition of clay and/or silicone binder.

    [0012] US 4,585,625 discloses that methyl isocyanate in waste gaseous emissions is abated at temperatures substantially lower than those required in the conventional operation of. a Process Thermal Oxidizer by contacting the waste gaseous emission with one or more transition meta] oxide catalysts at a temperature of at least about 400° C.

    [0013] DE 40 07 965 A1 discloses an air purification catalyst that can be either applied as a coating on water coolers, oil cooler or air coolers and used directly in the cooler. The catalyst can be regenerated by raising the temperature of the cooler.

    [0014] WO 2013/163536 A1 discloses aspects of the invention relate to a method of treating a gas stream generated by a motorcycle, the method comprising: contacting a gas stream containing hydrocarbons, carbon monoxide and nitrogen oxides and generated by a motorcycle under both rich and lean engine operating conditions with a base metal catalyst composition, thereby removing at least a part of the hydrocarbons, carbon monoxide and nitrogen oxides in gas stream. The base metal catalyst composition comprises a support including at least 10% by weight of reducible ceria, and about 3 to about 7 wt% MnO and about 8 to about 22 wt% CuO on the reducible ceria support. The base metal catalyst composition is effective to promote a steam reforming reaction of hydrocarbons and a water gas shift reaction to provide H2 as a reductant to abate NOx.

    [0015] EP 2 939 741 A1 discloses catalyst which can be used for purifying an exhaust gas to be discharged from an internal-combustion engine such as a gasoline engine and a diesel engine of two-wheel or four-wheel automobiles and a catalyst composition used in the catalyst.

    [0016] There continues to be a need for systems, methods, and compositions for effectively treating pollution at ground level and at high altitudes. These methods and compositions should exhibit long-term performance, efficient manufacturing operations, and reduced production costs.

    SUMMARY



    [0017] In a first aspect, the present invention is directed to use of a base metal only catalyst device for purifying an air supply of ozone and volatile organic compounds, the base metal only catalyst device comprising: (a) a housing; (b) a solid substrate disposed within the housing; and (c) a catalyst layer disposed on the solid substrate, wherein the catalyst layer comprises: (i) a first base metal catalyst which is copper oxide at a first mass percent; (ii) a second base metal catalyst which is manganese oxide at a second mass percent; and (iii) an oxygen donating support material comprising a rare earth metal oxide impregnated with at least one of the first base metal catalyst or the second base metal catalyst.

    [0018] In a second aspect, the present invention is directed to a method for purifying an air flow stream, the method comprising: contacting an unpurified air flow stream with the catalyst layer of the base metal only catalyst device of claims 1 to 6 to produce a purified air flow stream, wherein: the unpurified air flow stream contains a first ozone content, the purified air flow stream contains a second ozone content that is less than the first ozone content.

    [0019] Disclosed herein are methods, devices, and systems for purifying an air supply of ozone and volatile organic compounds. Also disclosed herein are methods for producing catalyst devices.

    [0020] The present application discloses a catalyst device including a housing, a solid substrate disposed within the housing, and a catalyst layer disposed on the substrate. The catalyst layer includes a first base metal catalyst at a first mass percent, a second base metal catalyst at a second mass percent, and a support material impregnated with at least one of the first base metal catalyst or the second base metal catalyst.

    [0021] The present application also discloses a device, in which the catalyst layer is to remove one or more of ozone, carbon dioxide, carbon monoxide, nitrous oxide, amines, sulfur compounds, thiols, chlorinated hydrocarbons, or volatile organic compounds from an unpurified air supply.

    [0022] The present application also discloses a device, in which the first base metal catalyst is copper oxide at a first mass percent and the second base metal catalyst is manganese oxide at a second mass percent. For example, the first base metal catalyst may be copper oxide at a first mass percent between 1% and 30%, between 5% and 15%, or between 8% and 12%. As another example, the second base metal catalyst may be manganese oxide at a second mass percent between 1% and 30%, between 5% and 15%, or between 8 and 12%.

    [0023] The present application also discloses a device, in which the support material is an oxygen donating support, which may have a surface area of at least 50 m2/g, of at least 100 m2/g, between 50 m2/g to 5000 m2/g, or between 100 m2/g to 300 m2/g. The support material may have a pore volume between 0.1 cm3/g (cc/g) to 10 cm3/g (cc/g), between 0.3 cm3/g (cc/g) to 3 cm3/g (cc/g), or between 0.3 cm3/g (cc/g) to 1.2 cm3/g (cc/g). The support material may be or include a refractory oxide, and may be or include a material selected from the group including ceria, alumina, titania, silica, zirconia, carbons, metal organic framework, clay, zeolites, and combinations thereof.

    [0024] The present application also discloses a device, in which a density of the catalyst layer may be between 183.07 g/m3 (0.003 g/in3) and 4759.85 g/m3 (0.078 g/in3), between 915.36 g/m3 (0.015 g/in3) and 3783.47 g/m3 (0.062 g/in3), or between 2379.92 g/m3 (0.039 g/in3) and 2868.12 g/m3 (0.047 g/in3). A thickness of the catalyst layer may be between about 10 nanometers and about 10 millimeters, between 500 nanometers and 1 millimeter, or between 1 micrometer and 500 micrometers.

    [0025] The present application also discloses a device, in which the solid substrate is a nonwoven filter, a paper filter, a ceramic filter, or a fibrous filter. The present application also discloses a device, in which the solid substrate is a metallic foam substrate, a ceramic foam substrate, or a polymer foam substrate. The present application also discloses a device, in which the solid substrate is a metallic honeycomb substrate, a ceramic honeycomb substrate, a paper honeycomb substrate, or a ceramic fiber honeycomb substrate. The present application also discloses a device, in which the solid substrate is a surface of a heat exchanger, a radiator, a heating core, or a condenser. The present application also discloses a device, in which the solid substrate is an HVAC duct, an air filter, or a louver surface.

    [0026] The catalyst device may be configured to contact the received unpurified air with the catalyst layer, in which ozone present in the received unpurified air is converted to oxygen upon contact with the catalyst layer. The received unpurified air may have an initial ozone content, and the purified air may have a final ozone content that is less than the initial ozone content. For example, the final ozone content of the purified air may be less than about 20% of the initial ozone content of the received unpurified air, or less than about 10% of the initial ozone content of the received purified air.

    [0027] In one aspect, a method for purifying an air flow stream includes contacting an unpurified air flow stream with a catalyst layer to produce a purified air flow stream. The unpurified air flow stream contains a first ozone content, and the purified air flow stream contains a second ozone content that is less than the first ozone content. The catalyst layer includes a first base metal catalyst, a second base metal catalyst, and a support material.

    [0028] The present application also discloses a method, in which the catalyst layer is disposed on a solid substrate. The solid substrate may be a heat exchanger, and may be part of an automobile ventilation unit. The present application also discloses a method, in which the solid substrate is part of an aircraft environmental control system. The present application also discloses a method, in which the solid substrate is part of an HVAC system.

    [0029] The present application also discloses a method, in which the solid substrate is a nonwoven filter, a paper filter, a ceramic filter, or a fibrous filter. In another implementation of the method, the solid substrate is a metallic foam substrate, a ceramic foam substrate, or a polymer foam substrate. The present application also discloses a method, in which the solid substrate is a metallic honeycomb substrate, a ceramic honeycomb substrate, a paper honeycomb substrate, or a ceramic fiber honeycomb substrate. The present application also discloses a method, in which the solid substrate is a surface of a heat exchanger, a radiator, a heating core, or a condenser. The present application also discloses a method, in which the solid substrate is an HVAC duct, an air filter, or a louver surface.

    [0030] The present application also discloses a method, in which contacting the unpurified air flow stream with the catalyst layer removes at least one of carbon dioxide, carbon monoxide, nitrous oxide, or a volatile organic compound from the unpurified air flow stream to produce the purified air flow stream.

    [0031] The present application also discloses a method, in which the first base metal catalyst is copper oxide at a first mass percent and the second base metal catalyst is manganese oxide at a second mass percent. For example, the first base metal catalyst is copper oxide at a first mass percent of between 1% and 30%, between 5% and 15%, or between 8% and 12%. The second base metal catalyst may be manganese oxide at a second mass percent between 1% and 30%, between 5% and 15%, or between 8% and 12%.

    [0032] The present application also discloses a method, in which the support material is an oxygen donating support, which may have a surface area of at least about 50 m2/g, of at least about 100 m2/g, of 50 m2/g to 5000 m2/g, or of 100 m2/g to 300 m2/g. The support material may have a pore volume of 0.1 cm3/g (cc/g) to 10 cm3/g (cc/g), of 0.3 cm3/g (cc/g) to 3 cm3/g (cc/g), or of 0.3 cm3/g (cc/g) to 1.2 cm3/g (cc/g).

    [0033] The present application also discloses a method, in which the support material may be or include a refractory oxide, and may be or include a material selected from the group consisting of ceria, alumina, titania, silica, zirconia, carbons, metal organic framework, clay, zeolites, and combinations thereof.

    [0034] The present application also discloses a method, in which a density of the catalyst layer may be between 183.07 g/m3 (0.003 g/in3) and 4759.85 g/m3 (0.078 g/in3), between 915.36 g/m3 (0.015 g/in3) and 3783.47 g/m3 (0.062 g/in3), or between 2379.92 g/m3 (0.039 g/in3) and 2868.12 g/m3 (0.047 g/in3). A thickness of the catalyst layer may be between 10 nanometers and 10 millimeters, between about 500 nanometers and about 1 millimeter, or between 1 micrometer and 500 micrometers.

    [0035] The present application also discloses a method, in which the second ozone content of the purified air flow stream may be less than about 20% of the first ozone content of the unpurified air flow stream, or may be less than about 10% of the first ozone content of the received purified air flow stream.

    [0036] The present application also discloses a method, in which the unpurified air flow stream is one or more of an aircraft jet engine bleed air stream, recirculated aircraft cabin air, or a non-bleed air stream. The purified air flow stream may be air flowing into a cabin or cockpit of an aircraft.

    [0037] The present application also discloses a method, in which the unpurified air flow stream may be air flowing into an automobile ventilation unit. The purified air flow stream may be air flowing out of an automobile ventilation unit and into an automobile interior.

    [0038] The present application also discloses a method, in which the unpurified air flow stream may be air flowing into a building from outside of the building, or may be recirculated air from inside of a building flowing into an HVAC system. The purified air flow stream may be air flowing into a building via an HVAC system.

    [0039] The present application also discloses a method, in which the unpurified air flow stream is air flowing into a portable air purifier.

    [0040] The present application also discloses a method for producing a catalyst device includes producing or providing a slurry, in which the slurry includes a first base metal catalyst, a second base metal catalyst, a support material, and a binder material. The method further includes depositing the slurry onto a surface of a solid substrate, and calcining the deposited slurry to produce a catalyst layer disposed on the surface of the solid substrate. The solid substrate is placed into an air purification chamber, in which the solid substrate is arranged such that when an air flow is introduced into the air purification chamber, the catalyst layer contacts the air flow and converts ozone in the air flow into oxygen.

    [0041] The term "atmosphere" means is defined herein as the mass of air surrounding the earth. The term "ambient air" shall mean the atmosphere which is drawn or forced towards the outer surface of a composition or device as disclosed herein.

    [0042] The term "automobile" means any wheeled or unwheeled motorized machine or vehicle for (i) transporting of passengers or cargo or (ii) performing tasks such as construction or excavation moving. Vehicles can have, e.g., at least 2 wheels (e.g., a motorcycle or motorized scooter), at least 3 wheels (e.g., an all-terrain vehicle), at least 4 wheels (e.g., a passenger automobile), at least 6 wheels, at least 8 wheels, at least 10 wheels, at least 12 wheels, at least 14 wheels, at least 16 wheels or at least 18 wheels. The vehicle can be, e.g., a bus, refuse vehicle, freight truck, construction vehicle, heavy equipment, military vehicle or tractor. The vehicle can also be a train, aircraft, watercraft, submarine or spacecraft.

    [0043] The term "radiator" means an apparatus to effect cooling to an associated device through heat exchange.

    [0044] The terms "stream" or "flow" broadly refers to any combination of flowing gas that may contain solid, liquid, or gaseous matter.

    [0045] The terms "unpurified air" or "unpurified air stream" refers to any stream that contains one or more pollutants at a concentration or content at or above a level considered to have adverse effects on human health (including short term and/or long term effects). Unpurified air may include, but is not limited to, ozone, carbon monoxide (CO), volatile organic compounds (VOCs), methyl bromide, water, and nitrogen.

    [0046] The terms "purified air" or "purified air stream" refer to any stream that contains one or more pollutants at a concentration or content below a level considered to have adverse effects on human health (e.g., effectively free of pollutants).

    [0047] The term "support" refers to the underlying high surface area material (e.g., ceria, ceria/zirconia, titania, etc.) upon which additional chemical compounds or elements are carried.

    [0048] The term "substrate" refers to the monolithic material onto which the support is placed. In some implementations, the substrate may be in the form of a solid surface having a washcoat containing a plurality of supports having catalytic species thereon. A washcoat may be formed by preparing a slurry containing a specified solids content (e.g., 30-50% by weight) of supports in a liquid vehicle, which is then coated onto a substrate and dried to provide a washcoat layer.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0049] The above and other features of the present disclosure, their nature, and various advantages will become more apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which:

    Figure 1 depicts a cross sectional view of a catalyst layer deposited on a solid support in accordance with an implementation;

    Figure 2 depicts a block diagram illustration of an aircraft environmental control system ("ECS") in accordance with an implementation;

    Figure 3A depicts a side cross-sectional view of an automobile ventilation system in accordance with an implementation;

    Figure 3B depicts a side cross-sectional view of an automobile radiator-air conditioning condenser assembly in accordance with an implementation;

    Figure 3C depicts a partial perspective view of a radiator with fins coated with a catalyst layer in accordance with an implementation;

    Figure 4 depicts a heating, ventilation, and air-conditioning ("HVAC") system in accordance with an implementation;

    Figure 5 shows an illustrative process for producing a catalyst device in accordance with an implementation;

    Figure 6 is a plot depicting ozone conversion for various compositions; and

    Figures 7A-7C are plots showing the effects of aging cycles on various compositions.


    DETAILED DESCRIPTION



    [0050] The present disclosure relates to the use of base metal only catalysts for the conversion of ozone, hydrocarbons, carbon monoxide, and various VOCs into less harmful compounds such as oxygen, carbon dioxide and water vapor. In certain implementations, a catalyst including manganese oxide and copper oxide catalysts supported on ceria is shown to convert ozone to oxygen at higher efficiencies than the palladium metal catalyst including VOC conversion functionality without including platinum catalyst.

    [0051] In one implementation, the disclosure is directed to treatment of aircraft jet engine bleed air for an ECS air supply. For treating aircraft jet engine bleed air, precious metal catalysts meet the high performance demands (> 90% conversion at 1,000,000 hr-1 SV and 200C), and thus have been used exclusively in ECS catalytic converters. The current catalysts for treating aircraft ozone utilize a palladium/manganese catalyst support on a high surface area alumina/silica support with an option to add a platinum catalyst on a high surface area support for additional VOC conversion functionality. However, the levels of precious metal in these catalysts are exceptionally high: 6533,21 to 8828,67 g/m3 (185 to 250 g/ft3) of palladium and optionally 3037,06 g/m3 (86 g/ft3) of platinum. With the strict performance requirements for ozone conversion mandated by FAA regulations, attempts to reduce cost are typically constrained by ozone conversion performance levels.

    [0052] The catalysts disclosed herein may be utilized in applications other than treating aircraft ECS air supplies. In one implementation, the disclosure is directed to a surface treatment of a heat exchange device (e.g., an automobile radiator) so that pollutants, such as ozone and VOC, contained in ambient air may be readily converted to less harmful compounds.

    [0053] The flow of ambient air through a heat exchange device, for example, may be treated in accordance with the implementations described herein. In certain aspects of the disclosure, the outer surface of the heat exchange device is capable of catalytically converting pollutants to less harmful compounds without adversely affecting the heat exchange activity of the device. In other aspects of the disclosure, the heat exchanger may provide an acceptable catalytic activity that is maintained over the useful life of the device. In other aspects of the disclosure, the intended activity may be obtained with a single coat of catalytic material onto the substrate (e.g., the heat exchanger).

    [0054] The various implementations are now described with reference to the following Figures and examples. Before describing several exemplary implementations, it is to be understood that the present disclosure is not limited to the details of construction or process steps set forth in the following description. Other implementations may be practiced or carried out in various ways in accordance with the principles described.

    [0055] Figure 1 depicts a cross sectional view of a catalyst layer deposited on a solid support in accordance with an implementation. A catalyst 100 is formed by placing a catalyst layer 102 on a substrate 104, and may include an adhesive layer 108 that adheres the catalyst layer 102 to the substrate 104. The catalyst layer 102 may be porous and may have a high surface area surface 106 that contacts an air flow. The high surface area surface 106 facilitates turbulent air flow in the vicinity of the catalyst layer 102 such to increase the amount of exposure of pollutants within the air flow to the catalyst layer 102. The catalyst layer 102 and the adhesive layer 108 are not shown to scale.

    [0056] In certain implementations, the catalyst layer 102 is a base metal catalyst. An exemplary base metal catalyst for ozone/VOC conversion includes about 10% manganese oxide by mass and about 10% copper oxide by mass supported on cerium oxide (CeO2), which is also known as ceria. The base metal catalyst is prepared, for example, by generating a slurry having target amounts of copper and manganese salts (e.g., acetate or nitrate based) mixed with both HSA-20 ceria and SBA-150 alumina in a 16:3 ratio. After addition of an alumina binder (Disperal P3), the slurry may then be coated onto a substrate (e.g., the substrate 104) at about 0.168 g/cm3 (2.75 g/in3) and calcined at about 500 °C. Calcining generates the final catalyst layer, which contains about 8.33% manganese oxide and 8.33% copper oxide based on total solids.

    [0057] In some implementations, a catalyst layer may include multiple layers or "sub-layers" of a catalyst material. Accordingly, it is to be understood that the term "catalyst layer", when referring to a catalyst material that includes different components, may refer to the components distributed within a single layer or the components separated into different layers. For example, a catalyst layer may include a first catalyst layer of a first base metal catalyst (e.g., manganese oxide) and a second catalyst layer of a second base metal catalyst (e.g., copper oxide). The first layer may be disposed on the second layer, or the second layer may be disposed on the first layer.

    [0058] In some implementations, there may be an overlayer on the catalyst coating or an underlayer between the substrate and the catalyst layer 102. The underlayer or overlayer may be a protective coat, an adhesion layer (e.g., the adhesion layer 108), or an additional catalyst layer. The adhesion layer 108, for example, may be a latex material or an acrylic material. In certain implementations, the catalyst layer 102 is adhered directly to the substrate 104 without the use of the adhesion layer 108. The protective coat may contain a protective substance which is stable at elevated temperatures (e.g., up to 120° C) and may be resistant to chemicals, salts, dirt and other contaminants which may adversely affect the catalyst composition. The protective material may be, e.g., a plastic or polymeric material such as polyethylene, polypropylene, polytetrafluoroethylene, styrene acrylic or a combination thereof.

    [0059] The catalyst layer 102 may have a dispersion of catalyst, for example, of from 50% to 95% or from 60% to 80% of manganese oxide and/or copper oxide crystallite domains measured less than 30 nm using the primary crystallite dimension of the domains within the high surface area support structure based on transmission electron microscopy.

    [0060] In other implementations, the catalyst layer 102 may have a dispersion of catalyst, for example, of from 50% to 95% or from 60% to 80% of manganese oxide and/or copper oxide crystallite domains measured less than 15 nm using the primary crystallite dimension of the domains within the high surface area support structure based on transmission electron microscopy.

    [0061] In certain implementations, the catalyst layer 102 is a physical mixture of metal oxide catalysts particles and high surface area support particles such that separate domains of metal oxide and support can function independently as catalyst and aging protection, respectively.

    [0062] In certain implementations, the catalyst layer 102 is an alloy of metal oxide catalysts and high surface area support such that the function of each material is inseparable from the other.

    [0063] In certain implementations, the catalyst 100 is a high surface area support particle which is in surface contact either within the pore structure and/or externally with small (<100nm) domains of metal oxide catalysts such that separate domains of metal oxide can function independently as catalyst and are provided protection from aging mechanisms within the support material.

    [0064] In certain implementations, the catalyst 100 is a high surface area support particle which is externally coated with a porous shell structure of metal oxide catalyst material such that the metal oxide catalyst function is external to the support providing a high surface area interior to the composite particle.

    [0065] In certain implementations, the catalyst 100 is a high surface area support which is encompassing a metal oxide particle in a coating layer such that the metal oxide catalyst is entirely surrounded by a protective high surface area support material.

    [0066] In certain implementations, the catalyst layer 102 has a relatively high thermal conductivity while maintaining pollutant destruction efficiency. In one aspect of the disclosure, high thermal conductivity materials (e.g., in the form of particles) may be blended into the coating to provide or enhance the thermal conductivity property of the coating without significantly impacting on diffusion through the coating. Non-limiting examples of such materials include metals such as aluminum, graphite, silicon carbide and sapphire. The material can be in the form of particles (e.g., flakes). The particle size may be any suitable size. In one implementation, the particles are on the order of the size of the catalyst and/or no more than the desired thickness of the coating. For example, the particles may have a mean size from 1 micron to 30 microns, or from 1 micron to 10 microns. The materials (e.g., particles) may be including in the coating in an amount of from 1% to 50% by weight of the total coating.

    [0067] Figure 2 shows an exemplary aircraft environmental control system ("ECS"), to illustrate the use of the catalyst device of the invention. The ECS 200 includes a catalyst chamber 204, a heat exchanger 208, and an air conditioning system 212. The ECS 200 receives air, such as bleed air 202 from the aircraft's engine. Bleed air 202 may be compressed air received by the catalyst chamber 204. In some implementations, non-bleed air may be received by the catalyst chamber 204 in lieu of bleed air 202 or concurrently with bleed air 202. The catalyst chamber 204 serves as a housing for a catalyst layer disposed within, and may be located, for example, in a lower portion of the aircraft between an air intake for the bleed air 202 and the heat exchanger 208. The interior walls of the catalyst chamber may be lined with a base metal catalyst material (e.g., the catalyst layer 102 described with respect to Figure 1), such that when an air flow into the catalyst chamber 204 contacts the catalyst material, pollutants, such as ozone and volatile organic compounds, are removed or converted. For example, a base metal catalyst capable of converting ozone to oxygen, as described herein, may line the interior walls of the catalyst chamber 204.

    [0068] In some implementations, the interior of the catalyst chamber 204 may include a tortuous flow air flow path in order to promote mixing of air within the catalyst chamber 204 and increase the amount of exposure of the air-borne pollutants to the catalyst material. In some implementations, precooling unit may also be included and located upstream relative to the catalyst chamber 204. The precooling unit may lower the temperature of air entering the catalyst chamber 204 prior to conversion or removal of ozone and other pollutants.

    [0069] The heat exchanger 208 receives purified air 206, where the purified air is cooled to or near to ambient temperatures. The heat exchanged air 210 is then received by the air conditioning system 212, which regulates the temperature of the air to deliver cabin-ready air 214 into the cabin of the aircraft. In some implementations, the air conditioning system 212 also regulates the humidity of the cabin-ready air by including a water extraction unit. In some implementations, recirculated cabin air 216 is flowed from the cabin and back into the catalyst chamber 204.

    [0070] In some implementations, the interior walls of various passageways are coated with the catalyst material, as well as the interiors of the heat exchanger 208 and air conditioning system 212. In some implementations, one or more of the heat exchanger 208 and the air conditioning system 212 may be consolidated into the catalyst chamber 204.

    [0071] In some implementations, a catalyst device is incorporated into an aircraft fuel tank inerting system (FTIS). Unpurified air received by the catalyst device may be one or more of recirculated aircraft cabin air, aircraft jet engine bleed air, or non-bleed air. Purified air may be directed to flow into an air separation component of the FTIS or an ullage of the fuel tank.

    [0072] Figure 3A depicts a side cross-sectional view of an automobile ventilation system in accordance with an implementation, to illustrate the use of the catalyst device of the invention. An automobile frame 301 supports a grille 302 for air inlet, which is located at a front end of the automobile. The frame 301 also supports an air inlet 304 for delivering air into the interior of the automobile. Unpurified ambient air 306 is received by an air ventilation unit 308 via the air inlet 304, and passes into a filter unit 310. The filter unit 310 may include air filters to remove particulars from the ambient air 306, and may also serve as a catalyst device housing. For example, the interior walls of the filter unit 310 may be coated with a base metal catalyst layer (e.g., the catalyst layer 102 described with respect to Figure 1) in order to remove pollutants, such as ozone and volatile organic compounds. Portions of filtration components within the filter unit 310 may also be lined with a base metal catalyst layer.

    [0073] Purified air passes through an outlet 312 and into the interior of the automobile via a face vent 316, a demister vent 318, and a foot-well vent 314. In some implementations, the interior walls of the air outlet 312 and each of the vents 314, 316, and 318 may be lined with a base metal catalyst to further purify the air delivered into the automobile of pollutants.

    [0074] Figure 3B depicts a side cross-sectional view of an automobile radiator-air conditioning condenser assembly in accordance with an implementation, to illustrate the use of the catalyst device of the invention. The automobile includes a frame 352, which may be the same as the frame 301 described with respect to Figure 3A. A front end of the automobile has a grille 350, which may be the same as the grille 302 described with respect to Figure 3A, and which is supported on the front of the frame 352. An air conditioner condenser 354, a radiator 356, and a radiator fan 358 may be located within the frame 352. One or more of these components may be coated with the base metal catalyst layers disclosed herein.

    [0075] Figure 3C depicts a partial perspective view of a radiator with fins coated with a catalyst layer in accordance with an implementation, to illustrate the use of the catalyst device of the invention. A radiator 370 (which may be the same as radiator the 356 described with respect to Figure 3B) may include spaced apart tubes 372 for the flow of a first fluid. The tubes are arranged horizontally through the radiator 370, and a series of corrugated plates 374 are inserted therebetween defining a pathway 376 for the flow of a second fluid transverse to the flow of the first fluid. The first fluid, such as antifreeze, is supplied from a source to the tubes 372 through an inlet 378. The antifreeze enters the radiator 370 at a relatively low temperature through the inlet 378, eventually leaves the radiator through an outlet 380, and may be recirculated. The second fluid may be ambient air that passes through the pathway 376 and exchanges heat with the first fluid passing through the tubes 372. The corrugated plates 374 may be coated with base metal catalyst layers (e.g., the catalyst layer 102 described with respect to Figure 1) in order to convert or remove pollutants, such as ozone and volatile organic compounds, from the ambient air. In certain implementations, the radiator is provided with projections 382 (e.g., fins), which are non-heat exchange surfaces directed along the air-flow path. The projections 382 may be coated with base metal catalyst layers as disclosed herein.

    [0076] Figure 4 depicts a heating, ventilation, and air-conditioning ("HVAC") system in accordance with an implementation, to illustrate the use of the catalyst device of the invention. HVAC system 400 may be, for example, located within the interior of a residential building, an office building, or any other closed structure for which ventilation is utilized. HVAC system 400 may be part of a house and may be partially located in a basement or crawl space of the house, with ducts arranged to provide ventilation to each room of the house.

    [0077] Ambient air 402 enters HVAC system 400 through inlet filter 404. Inlet filter 404 may be an air filter to filter the air as it enters, or may be a screen used to prevent pests (e.g., insects and animals) from entering the HVAC system 400. One or more fans 414 may be utilized to produce a negative pressure within the HVAC system 400 that draws in ambient air 402. Recirculated air 408 from inside of the building also enters the HVAC system 400. The HVAC system 400 also includes a vent 422 to allow air to flow out of the HVAC system 400 in the case of overpressure.

    [0078] The recirculated air 408 and ambient air 402 mix together in mixing chamber 406, which then passes through various HVAC components prior to entering the house through vents 410. Mixed air may first pass through a primary air filter 412, which may be a high-efficiency particular air (HEPA) filter. Air is forced through the air filter 412 by the fan 414, and then passes into a heating/cooling unit 416 that exchanges heat with the passing air. The heating/cooling unit 416 may be include power supplies and electrical connectivity to a thermostat located within the building. Additional components utilized by the heating/cooling unit 416 may include, for example, a humidifier and/or a drip pan for capturing and funneling out condensed water. The HVAC system 400 may also include an additional air filter 418 prior to delivering air through vents 410.

    [0079] In some implementations, the HVAC system 400, or the components thereof, may act as a catalyst device housing by including base metal catalyst layers deposited on various surfaces throughout to convert or remove ozone, volatile organic compounds, and other pollutants from the ambient air prior to ventilating the building. For example, base metal catalysts may coat interior walls 420 of the mixing chamber 406, or any other walls within the HVAC system 400. In some implementations, filters 404, 412, and 418 may include catalyst layers along their surfaces such that air may pass through while simultaneously contacting the catalyst layers. In some implementations, the blades of fan 414 may be coated with a catalyst layer.

    [0080] Figure 5 shows an illustrative process for producing a catalyst device used in the method of the present invention. The process begins at block 502, where a slurry is produced or provided. The slurry includes a first base metal catalyst, a second base metal catalyst, a support material, and a binder material.

    [0081] In some implementations, the support is an oxygen donating support. As used herein, the term "oxygen donating" refers to a material that can donate oxygen to the adjacent surface of a catalyst material. The oxygen donating support and base metal catalysts can be prepared into solid phase mixtures through wet chemistry processes such as incipient wetness impregnation, co-precipitation, post-dip impregnation, deposition precipitation, single-pot, or other processes. These elements can also be added together with active base metal components during catalyst preparation without use of the pre-formed oxides as supports.

    [0082] In some implementations, the support material for the first base metal catalyst can be comprised of one or more materials that selected from ceria, praseodymia, neodymia, lanthana, yttria, titania, zirconia, and combinations thereof. Examples of suitable oxygen donating supports comprise the rare earth oxides, particularly ceria. The oxygen donating support can include cerium oxide (CeO2) in a form that exhibits oxygen donating properties.

    [0083] In some implementations, the oxygen donating support contains other elements/components to improve the reducibility of the support and/or to stabilize the support against loss of surface area and structure integrity under high temperature hydrothermal aging condition. Such components can include Pr, Nd, Sm, Zr, Y, Si, Ti and La, which may be present in an amount of up to about 60 wt%. Thus, in further implementations, the ceria may be doped with up to about 90% by weight of one or more oxides of Pr, Nd, Sm, Zr, Y and La. In further implementations, the ceria is doped with one or more oxides of these elements in an amount less than or equal to about 60 wt%, or from 1 to 50 wt%. In one implementation, the oxygen donating support is substantially free of oxides of aluminum. In one or more implementations, the support comprises a mixture of ceria and zirconia, and the ratio of Ce/Zr is no less than 4:1.

    [0084] In some implementations, the first base metal catalyst is supported on an oxygen donating support material that is substantially free of alumina. The oxygen donating support material may include one or more of ceria (CeO2), praseodymia (Pr2O3), neodymia (Nd2O3), lanthana (LaO2), yttria (YtO2), titania (TiO2), and combinations thereof. The oxygen donating support material may also include mixtures of these with other oxide materials such as with zirconia (ZrO2). Thus, the oxygen donating support may include composite oxides or mixed oxides of two or more thereof (such as CeZrO2 mixed oxides and TiZrO2 mixed oxides).

    [0085] The oxygen donating support material may also be stabilized. Stabilizers may be selected from zirconium (Zr), lanthanum (La), yttrium (Yt), praseodymium (Pr), neodymium (Nd), and oxide thereof, a composite oxide or mixed oxide of any two or more thereof or at least one alkaline earth metal (e.g., barium (Ba)).

    [0086] In some implementations, the oxygen donating support comprises a mixture of ceria and zirconia. Without intending to be bound by theory, it is believed that the zirconia aids in long term aging by preserving stability of the catalyst. Additionally, zirconia offers a less expensive alternative to ceria.

    [0087] It has been observed that the activity of the catalyst is proportional to the Ce/Zr ratio. Any ratio of Ce/Zr is possible, however, as the amount of ceria decreases (i.e., the higher the content of zirconia), the lower the activity of the catalyst. In some implementations, the ratio of Ce/Zr is no less than 4:1. In other words, the oxygen donating support can comprise 80% ceria and 20% zirconia, 75% ceria and 25% zirconia, 70% ceria and 30% zirconia, 65% ceria and 35% zirconia, 60% ceria and 40% zirconia, 65% ceria and 45% zirconia, 50% ceria and 50% zirconia, 40% ceria and 60% zirconia, 30% ceria and 70% zirconia, 20% ceria and 80% zirconia, 10% ceria and 90% zirconia, 0% ceria and 100% zirconia. In one implementation, the oxygen donating support comprises an equivalent amount of ceria and zirconia.

    [0088] In one or more implementations, the oxygen donating support includes at least 50% by weight of ceria. In a specific implementation, the oxygen donating support includes at least 99% by weight of ceria.

    [0089] In some implementations, the catalyst is prepared by incipient wetness impregnation. With incipient wetness impregnation, a solution of base metal catalyst precursors is dispensed into a well-mixed powder bed containing the oxygen donating support (e.g., ceria, ceria/zirconia, or titania). The powder is then calcined at about 500 °C after the first base metal catalyst is added, followed sequentially by the dispensing and calcining of the at least one second base metal catalyst. Alternatively, a solution containing both base metal catalyst precursors together can be dispensed into the well-mixed powder bed containing the support.

    [0090] In one implementation, when more than one base metal catalyst is present, one of the base metal catalysts may act as a base metal promoter. As used herein, the term "promoter" refers to a substance that when added into a catalyst, increases the activity of the catalyst.

    [0091] In implementations relating to supported base metal formulations, pre-made supports may be used for impregnation of the solution of active base metal or combination of base metals. The resulting catalyst can then be mixed with a suitable binder. Examples of a suitable binder include alumina sol, Boehmite, silica sol, titania sol, zirconium acetate, and colloidal ceria sol. Alternatively, the resulting catalyst may be calcined first, and then mixed with binder to make a suitable slurry for coating onto a substrate. In one implementation, the first base metal catalyst deposited on the oxygen donating support may be mixed with other based metal catalysts deposited on another support to make a slurry for coating onto the substrate.

    [0092] For a single-pot synthesis, the support, base metal catalyst precursors, binder, and any inert materials (e.g., added to increase washcoat porosity) may be mixed together to form a slurry.

    [0093] In some implementations, a base metal precursor solution (e.g. Cu and Mn nitrate) is slowly added to a suspension of support material, while the pH is regulated (controlled and adjusted) to keep the pH between 8 to 10 through the addition of a base. The pH is adjusted so that deposition of the base metal on and over the surface of the support material occurs. The resulting material may then be used for making a slurry.

    [0094] Returning to Figure 5, at block 504 the slurry is deposited onto a surface of a solid substrate (e.g., substrate 104). The slurry may be, for example, sprayed onto the solid substrate, dip-coated onto the solid substrate, or directly deposited onto the solid substrate.

    [0095] At block 506, the deposited slurry is calcined to produce a catalyst layer (e.g., catalyst layer 102) disposed on the surface of the solid substrate. In some implementations, the coated slurry is dried at about 120 °C for about 2 hours and calcined at a temperature ranging from 300 °C to 1000 °C. In some implementations, the slurry is calcined at a temperature ranging from 400 ° to 950 °C. In some implementations, the catalyst is calcined at a temperature ranging from 450 °C to 500 °C.

    [0096] In some implementations, a substrate is pre-coated with the slurry containing that catalyst, support, binder and other inert materials (e.g., alumina added for porosity). After drying and calcination, the coated substrate cores are dipped in a solution containing the base metal catalyst precursors. The completed cores are then dried and calcined at 500 °C to produce the final catalyst layer.

    [0097] At block 508, the solid substrate is placed into an air purification chamber, such as any of the chambers described herein. The solid substrate is then arranged such that when an air flow is introduced into the air purification chamber, the catalyst layer contacts the air flow and converts ozone in the air flow into oxygen. In certain implementations, other pollutants in the air flow may be converted into harmless or less harmful chemical species upon contact with the catalyst layer.

    [0098] At block 510, an unpurified air flow stream is contacted with the catalyst layer to produce a purified air flow stream. Block 510 may be performed downstream, for example, by a user of the catalyst device, and not necessarily as part of the production process outlined in blocks 502, 504, 506, and 508.

    [0099] It should be understood that the above steps of the flow diagrams of Figure 5 may be executed or performed substantially simultaneously, where appropriate.

    [0100] Figure 6 is a plot depicting ozone conversion for various compositions. Plot 600 shows an ozone conversion comparison of a base metal catalyst (copper and manganese) to palladium/manganese-based catalysts currently used in aircraft environmental control systems. At each testing temperature, 100 °C, 150 °C, and 200 °C, respectively, the copper/manganese/ceria catalyst appears to outperform both platinum/manganese/alumina and platinum/manganese/silica catalysts in terms of ozone conversion. While the copper/manganese catalyst is loaded on the ceramic support at 0,168 g/cm3 (2.75g/in3) and the Pd/Mn catalyst is at 0,065 g/cm3 (1.06 g/in3), a high density of ceria relative to the alumina/silica will result in a coating of similar thickness. The coating thickness is of particular interest because of pressure drop restrictions on the ozone/VOC converter systems in aircraft environmental control systems. Thus, it is likely that the higher density of material (and higher surface area) of the base metal catalyst may contribute to the increased performance over conventional precious metal catalysts.

    [0101] Figures 7A-7C are plots showing the effects of aging cycles on various compositions. Hydraulic fluid, for example, is a known contaminant in aircraft bleed air systems that can be exposed to the aircraft ozone/VOC catalyst. Previous work with field aged aircraft ozone/VOC converters has indicated phosphorous loading as a possible poison for decreasing the aged ozone conversion efficiencies of conventional Pd/Mn catalysts. A phosphate ester based hydraulic fluid was the used to rapidly expose the catalyst to high concentrations of phosphorus in an attempt to artificially age the catalyst samples. Figures 7A-7C demonstrate the ozone conversion efficiency after exposure to artificial aging conditions of an exemplary base metal catalyst (Cu/Mn on ceria) relative to a Pd/Mn catalyst. At each testing temperature, namely 200 °C, 150 °C, and 100 °C, the Cu/Mn catalyst outperforms the Pd/Mn catalyst and maintains high conversion with subsequent aging cycles.

    EXAMPLES



    [0102] The following examples are set forth to assist in understanding the implementations described herein and should not be construed as specifically limiting the implementations described and claimed herein. The following examples relate to the preparation of the catalysts used in the present invention.

    Example 1



    [0103] Manganese and copper nitrate salts were mixed with water to make a solution for the incipient wetness impregnation of cerium oxide. The cerium oxide was then impregnated with the solution and then dried for two hours at 110 °C and calcined at 500 °C for three hours. The manganese and copper loadings in the impregnated catalyst are equivalent to 10 wt% of MnO2 and 10 wt% of CuO on ceria. The impregnated sample was then mixed with water, an alumina sol binder (5 wt%), and alumina (15%) to form a slurry that contained about 42 wt% of solids. The pH of the slurry was adjusted to 4.0 with nitric acid. The slurry was then milled to a particle size suitable for washcoating. A catalyst layer was then prepared by washcoating the slurry onto a cordierite substrate with a cell density of 400 cpsi (62 cells/cm2). After washcoating, the catalyst layer was then dried at 120 °C for 2 hours and calcined at 500 °C for 2 hours. The catalyst layer loading was 0,168 g/cm3 (2.75 g/in3).

    Example 2



    [0104] Manganese and copper nitrate salts were mixed with water to make a solution for the incipient wetness impregnation of cerium oxide. The cerium oxide was then impregnated with the solution and then dried for two hours at 110 °C and calcined at 500 °C for three hours. The manganese and copper loadings in the impregnated catalyst were equivalent to 5 wt% of MnO2 and 10 wt% of CuO on ceria. The impregnated sample was then mixed with water and an alumina sol binder (5 wt%) to form a slurry that contained about 42 wt% of solids. The pH of the slurry was adjusted to 4.5 with nitric acid. The slurry was then milled to a particles size suitable for washcoating. A catalyst layer was then prepared by washcoating the slurry onto a cordierite substrate with a cell density of 400 cpsi. After washcoating, the catalyst layer was then dried at 120 °C for 2 hours and calcined at 500 °C for 2 hours. The catalyst layer loading was 0,104 g/cm3 (1.70 g/in3).

    Example 3



    [0105] The catalyst layer in this example was prepared following the same procedure described for Example 2, except the support used was a ceria-zirconia material that contained 80 wt% of ceria.

    Example 4



    [0106] The catalyst layer in this example was prepared following the same procedure described for Example 2, except the support used was a ceria-zirconia material that contained 45 wt% of ceria.

    Example 5



    [0107] The monolith catalyst in this example was prepared following the same procedure described for Example 2, except the support used was a ceria-zirconia material that contained 12.5 wt% of ceria.

    Example 6



    [0108] The monolith catalyst in this example was prepared following the same procedure described for Example 2, except the support used was titania.

    Example 7



    [0109] The monolith catalyst in this example was prepared following the same procedure described for Example 2, except the catalyst layer loading was 0,168 g/cm3 (2.75 g/in3).

    Example 8



    [0110] Manganese and copper nitrate salts were mixed with water to make a solution. This solution was added to a suspension of cerium oxide held at 80 °C. During the addition, the pH of the suspension was held between 8 to 10 with a solution of sodium hydroxide. The resulting powder was then filtered, washed with water, dried for two hours at 110 °C, and then calcined for three hours at 500 °C. The manganese and copper loadings were equivalent to 5 wt% of MnO2 and 10 wt% of CuO on ceria. The sample was then mixed with water and an alumina sol binder (5 wt%) to form a slurry that contained about 42 wt% of solids. The pH of the slurry was adjusted to 4.5 with nitric acid. The slurry was then milled to a particles size suitable for washcoating. A catalyst layer was then prepared by washcoating the slurry onto a cordierite substrate with a cell density of 400 cpsi. After washcoating, the catalyst layer was then dried at 120 °C for 2 hours and calcined.

    Example 11



    [0111] The monolith catalyst in the example was prepared following the same procedure described for Example 2, except the copper loading in the impregnated catalyst was equivalent to 20 wt% CuO.


    Claims

    1. Use of a base metal only catalyst device for purifying an air supply of ozone and volatile organic compounds, the base metal only catalyst device comprising:

    (a) a housing;

    (b) a solid substrate disposed within the housing; and

    (c) a catalyst layer disposed on the solid substrate, wherein the catalyst layer comprises:

    (i) a first base metal catalyst which is copper oxide at a first mass percent;

    (ii) a second base metal catalyst which is manganese oxide at a second mass percent; and

    (iii) an oxygen donating support material comprising a rare earth metal oxide impregnated with at least one of the first base metal catalyst or the second base metal catalyst.


     
    2. Use of the catalyst device of claim 1, wherein the first mass percent of the first base metal catalyst is between 1 wt% and 30 wt%, preferably between 5 wt% to 15 wt%, and more preferably between 8 wt% and 12 wt%, based on the oxygen donating support material.
     
    3. Use of the catalyst device of claim 1, wherein the second mass percent of the second base metal catalyst is between 1 wt% and 30 wt%, preferably between 5 wt% and 15 wt%, and more preferably between 8 wt% and 12 wt%, based on the oxygen donating support material.
     
    4. Use of the catalyst device of claim 1, wherein the oxygen donating support material has a surface area of at least 50 m2/g, preferably at least 100 m2/g, more preferably of 50 m2/g to 5000 m2/g, and most preferably of 100 m2/g to 300 m2/g.
     
    5. Use of the catalyst device of claim 1, wherein the support material has a pore volume of 0.1 cm3/g to 10 cm3/g, preferably of 0.3 cm3/g to 3 cm3/g, more preferably of 0.3 cm3/g to 1.2 cm3/g.
     
    6. Use of the catalyst device of claim 1, wherein the oxygen donating support material comprises ceria.
     
    7. A method for purifying an air flow stream, the method comprising:
    contacting an unpurified air flow stream with the catalyst layer of the base metal only catalyst device of claims 1 to 6 to produce a purified air flow stream, wherein:

    the unpurified air flow stream contains a first ozone content,

    the purified air flow stream contains a second ozone content that is less than the first ozone content.


     
    8. The method of claim 7, wherein the solid substrate is a nonwoven filter, a paper filter, a ceramic filter, or a fibrous filter, a metallic foam substrate, a ceramic foam substrate, or a polymer foam substrate, a metallic honeycomb substrate, a ceramic honeycomb substrate, a paper honeycomb substrate, or a ceramic fiber honeycomb substrate, a surface of a heat exchanger, a radiator, a heating core, or a condenser, an HVAC duct, an air filter, or a louver surface.
     
    9. The method of claim 7, wherein contacting the unpurified air flow stream with the catalyst layer further removes at least one of carbon dioxide, carbon monoxide, nitrous oxide, or a volatile organic compound from the unpurified air flow stream to produce the purified air flow stream.
     
    10. The method of claim 7, wherein a first mass percent of the first base metal catalyst in the catalyst layer is between 1 wt% and 30 wt%, preferably between 5 wt% to 15 wt%, and more preferably between 8 wt% and 12 wt%, based on the oxygen donating support material.
     
    11. The method of claim 7, wherein a second mass percent of the second base metal catalyst in the catalyst layer is between 1 wt% and 30 wt%, preferably between 5 wt% and 15 wt%, and more preferably between 8 wt% and 12 wt%, based on the oxygen donating support material.
     
    12. The method of claim 7, wherein the support material has a surface area of at least 50 m2/g, preferably at least 100 m2/g, more preferably of 50 m2/g to 5000 m2/g, and most preferably of 100 m2/g to 300 m2/g.
     
    13. The method of claim 7, wherein the support material has a pore volume of 0.1 cm3/g to 10 cm3/g, preferably of 0.3 cm3/g to 3 cm3/g, more preferably of 0.3 cm3/g to 1.2 cm3/g.
     


    Ansprüche

    1. Verwendung einer Nur-Basismetall-Katalysatorvorrichtung zum Reinigen einer Luftzufuhr von Ozon und flüchtigen organischen Verbindungen, wobei die Nur-Basismetall-Katalysatorvorrichtung Folgendes umfasst:

    (a) ein Gehäuse;

    (b) ein festes Substrat, das innerhalb des Gehäuses angeordnet ist; und

    (c) eine Katalysatorschicht, die auf dem festen Substrat angeordnet ist, wobei die Katalysatorschicht Folgendes umfasst:

    (i) einen ersten Basismetall-Katalysator, der zu einem ersten Massenprozent aus Kupferoxid besteht;

    (ii) einen zweiten Basismetall-Katalysator, der zu einem zweiten Massenprozent aus Manganoxid besteht; und

    (iii) ein sauerstoffabgebendes Trägermaterial, das ein Seltenerdmetalloxid umfasst, das mit mindestens einem des ersten Basismetall-Katalysators oder des zweiten Basismetall-Katalysators imprägniert ist.


     
    2. Verwendung der Katalysatorvorrichtung nach Anspruch 1, wobei der erste Massenprozentanteil des ersten Basismetall-Katalysators zwischen 1 Gew.-% und 30 Gew.-%, vorzugsweise zwischen 5 Gew.-% und 15 Gew.-% und noch bevorzugter zwischen 8 Gew.-% und 12 Gew.-%, bezogen auf das sauerstoffabgebende Trägermaterial, beträgt.
     
    3. Verwendung der Katalysatorvorrichtung nach Anspruch 1, wobei der zweite Massenprozentanteil des zweiten Basismetall-Katalysators zwischen 1 Gew.-% und 30 Gew.-%, vorzugsweise zwischen 5 Gew.-% und 15 Gew.-% und noch bevorzugter zwischen 8 Gew.-% und 12 Gew.-%, bezogen auf das sauerstoffabgebende Trägermaterial, beträgt.
     
    4. Verwendung der Katalysatorvorrichtung nach Anspruch 1, wobei das sauerstoffabgebende Trägermaterial eine Oberfläche von mindestens 50 m2/g, vorzugsweise von mindestens 100 m2/g, noch bevorzugter von 50 m2/g bis 5000 m2/g, und am meisten bevorzugt von 100 m2/g bis 300 m2/g aufweist.
     
    5. Verwendung der Katalysatorvorrichtung nach Anspruch 1, wobei das Trägermaterial ein Porenvolumen von 0,1 cm3/g bis 10 cm3/g, vorzugsweise von 0,3 cm3/g bis 3 cm3/g, noch bevorzugter von 0,3 cm3/g bis 1,2 cm3/g, aufweist.
     
    6. Verwendung der Katalysatorvorrichtung nach Anspruch 1, wobei das sauerstoffabgebende Trägermaterial Ceroxid umfasst.
     
    7. Verfahren zum Reinigen eines Luftstromes, das Verfahren Folgendes umfassend:
    Inkontaktbringen eines ungereinigten Luftstromes mit der Katalysatorschicht der Nur-Basismetall-Katalysatorvorrichtung nach den Ansprüchen 1 bis 6, um einen gereinigten Luftstrom zu erzeugen, wobei:
    der ungereinigte Luftstrom einen ersten Ozongehalt enthält, und der gereinigte Luftstrom einen zweiten Ozongehalt enthält, der geringer als der erste Ozongehalt ist.
     
    8. Verfahren nach Anspruch 7, wobei das feste Substrat ein Vliesstofffilter, ein Papierfilter, ein Keramikfilter oder ein Faserfilter, ein Metallschaumsubstrat, ein Keramikschaumsubstrat oder ein Polymerschaumsubstrat, ein metallisches Wabensubstrat, ein keramisches Wabensubstrat, ein Papierwabensubstrat oder ein Keramikfaser-Wabensubstrat, eine Oberfläche eines Wärmetauschers, ein Heizkörper, ein Heizkern oder ein Kondensator, ein HVAC-Kanal, ein Luftfilter oder eine Lamellenoberfläche ist.
     
    9. Verfahren nach Anspruch 7, wobei das Inkontaktbringen des ungereinigten Luftstromes mit der Katalysatorschicht weiter mindestens eines von Kohlendioxid, Kohlenmonoxid, Distickstoffoxid oder einer flüchtigen organischen Verbindung aus dem ungereinigten Luftstrom entfernt, um den gereinigten Luftstrom zu erzeugen.
     
    10. Verfahren nach Anspruch 7, wobei ein erster Massenprozentanteil des ersten Basismetall-Katalysators in der Katalysatorschicht zwischen 1 Gew.-% und 30 Gew.-%, vorzugsweise zwischen 5 Gew.-% und 15 Gew.-% und noch bevorzugter zwischen 8 Gew.-% und 12 Gew.-%, bezogen auf das sauerstoffabgebende Trägermaterial, beträgt.
     
    11. Verfahren nach Anspruch 7, wobei ein zweiter Massenprozentanteil des zweiten Basismetall-Katalysators in der Katalysatorschicht zwischen 1 Gew.-% und 30 Gew.-%, vorzugsweise zwischen 5 Gew.-% und 15 Gew.-%, und noch bevorzugter zwischen 8 Gew.-% und 12 Gew.-%, bezogen auf das sauerstoffabgebende Trägermaterial, beträgt.
     
    12. Verfahren nach Anspruch 7, wobei das Trägermaterial eine Oberfläche von mindestens 50 m2/g, vorzugsweise von mindestens 100 m2/g, noch bevorzugter von 50 m2/g bis 5000 m2/g und am meisten bevorzugt von 100 m2/g bis 300 m2/g aufweist.
     
    13. Verfahren nach Anspruch 7, wobei das Trägermaterial ein Porenvolumen von 0,1 cm3/g bis 10 cm3/g, vorzugsweise von 0,3 cm3/g bis 3 cm3/g, noch bevorzugter von 0,3 cm3/g bis 1,2 cm3/g, aufweist.
     


    Revendications

    1. Utilisation d'un dispositif de catalyseur uniquement à métal de base destiné à purifier une alimentation d'air de l'ozone et des composés organiques volatils, le dispositif de catalyseur uniquement à métal de base comprenant :

    (a) un boîtier ;

    (b) un substrat solide disposé à l'intérieur du boîtier ; et

    (c) une couche de catalyseur disposée sur le substrat solide, dans laquelle la couche de catalyseur comprend :

    (i) un premier catalyseur à métal de base qui est de l'oxyde de cuivre à un premier pourcentage en masse ;

    (ii) un second catalyseur à métal de base qui est de l'oxyde de manganèse à un second pourcentage en masse ; et

    (iii) un matériau support donneur d'oxygène comprenant un oxyde métallique de terres rares imprégné avec au moins l'un parmi le premier catalyseur à métal de base ou le second catalyseur à métal de base.


     
    2. Utilisation du dispositif de catalyseur selon la revendication 1, dans laquelle le premier pourcentage en masse du premier catalyseur à métal de base est compris entre 1 % en poids et 30 % en poids, de préférence entre 5 % en poids et 15 % en poids et plus préférentiellement entre 8 % en poids et 12 % en poids, sur la base du matériau support donneur d'oxygène.
     
    3. Utilisation du dispositif de catalyseur selon la revendication 1, dans laquelle le second pourcentage en masse du second catalyseur à métal de base est compris entre 1 % en poids et 30 % en poids, de préférence entre 5 % en poids et 15 % en poids et plus préférentiellement entre 8 % en poids et 12 % en poids, sur la base du matériau support donneur d'oxygène.
     
    4. Utilisation du dispositif de catalyseur selon la revendication 1, dans laquelle le matériau support donneur d'oxygène présente une superficie d'au moins 50 m2/g, de préférence d'au moins 100 m2/g, plus préférentiellement de 50 m2/g à 5 000 m2/g et idéalement de 100 m2/g à 300 m2/g.
     
    5. Utilisation du dispositif de catalyseur selon la revendication 1, dans laquelle le matériau support présente un volume poreux de 0,1 cm3/g à 10 cm3/g, de préférence de 0,3 cm3/g à 3 cm3/g, plus préférentiellement de 0,3 cm3/g à 1,2 cm3/g.
     
    6. Utilisation du dispositif de catalyseur selon la revendication 1, dans laquelle le matériau support donneur d'oxygène comprend de la cérine.
     
    7. Procédé destiné à purifier un flux d'écoulement d'air, le procédé comprenant :
    la mise en contact d'un flux d'écoulement d'air non purifié avec la couche de catalyseur du dispositif de catalyseur uniquement en métal de base des revendications 1 à 6 pour produire un flux d'écoulement d'air purifié, dans lequel :
    le flux d'air non purifié contient une première teneur en ozone, le flux d'air purifié contient une seconde teneur en ozone qui est inférieure à la première teneur en ozone.
     
    8. Procédé selon la revendication 7, dans lequel le substrat solide est un filtre non tissé, un filtre en papier, un filtre en céramique ou un filtre fibreux, un substrat en mousse métallique, un substrat en mousse céramique ou un substrat en mousse polymère, un substrat en nid d'abeilles métallique, un substrat en nid d'abeilles en céramique, un substrat en nid d'abeilles en papier ou un substrat en nid d'abeilles en fibre de céramique, une surface d'un échangeur de chaleur, un radiateur, un noyau chauffant ou un condenseur, un conduit de CVCA, un filtre à air ou une surface de volet.
     
    9. Procédé selon la revendication 7, dans lequel la mise en contact du flux d'écoulement d'air non purifié avec la couche de catalyseur élimine en outre au moins l'un parmi le dioxyde de carbone, le monoxyde de carbone, l'oxyde nitreux ou un composé organique volatil provenant du flux d'écoulement d'air non purifié pour produire le flux d'écoulement d'air purifié.
     
    10. Procédé selon la revendication 7, dans lequel un premier pourcentage en masse du premier catalyseur à métal de base dans la couche de catalyseur est compris entre 1 % en poids et 30 % en poids, de préférence entre 5 % en poids et 15 % en poids, et plus préférentiellement entre 8 % en poids et 12 % en poids, sur la base du matériau support donneur d'oxygène.
     
    11. Procédé selon la revendication 7, dans lequel un second pourcentage en masse du second catalyseur à métal de base dans la couche de catalyseur est compris entre 1 % en poids et 30 % en poids, de préférence entre 5 % en poids et 15 % en poids, et plus préférentiellement entre 8 % en poids et 12 % en poids, sur la base du matériau support donneur d'oxygène.
     
    12. Procédé selon la revendication 7, dans lequel le matériau support présente une superficie d'au moins 50 m2/g, de préférence d'au moins 100 m2/g, plus préférentiellement de 50 m2/g à 5 000 m2/g et idéalement de 100 m2/g à 300 m2/g.
     
    13. Procédé selon la revendication 7, dans lequel le matériau support présente un volume poreux de 0,1 cm3/g à 10 cm3/g, de préférence de 0,3 cm3/g à 3 cm3/g, plus préférentiellement de 0,3 cm3/g à 1,2 cm3/g.
     




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    Cited references

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    Patent documents cited in the description