Voc oxidation catalyst, method for preparing the same, and use thereof in catalytic oxidation of vocs

Abstract

The application relates to the technical field of 3D printing and catalytic material preparation, and discloses a VOCs oxidation catalyst, a preparation method thereof and application of the VOCs oxidation catalyst in catalytic oxidation of VOCs. The preparation method of the catalyst comprises the following steps: obtaining an embryo with a hollow lattice structure through 3D printing; performing defatting, sintering and alkali treatment on the embryo to obtain a 3D printed ceramic carrier; loading catalyst slurry on the surface of the 3D printed ceramic carrier, and then performing drying and calcination treatment to obtain the VOCs oxidation catalyst. The VOCs oxidation catalyst is prepared through the above method, is rich in interconnected pores, has a large specific surface area and a high catalyst loading capacity, has a low catalytic temperature, and can realize catalytic oxidation of VOCs at a high air speed and a low temperature.

Description

Technical Field

[0001] This invention relates to the field of 3D printing and catalytic material preparation technology, specifically to a VOCs oxidation catalyst and its preparation method, as well as the application of the VOCs oxidation catalyst in the catalytic oxidation of VOCs. Background Technology

[0002] Volatile organic compounds (VOCs) are substances with boiling points between 50-260℃ and saturated vapor pressures above 133.3 Pa at room temperature. They include hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, aldehydes, ketones, and polycyclic aromatic hydrocarbons. VOCs are major pollutants emitted during the production and processing of various industries such as petrochemicals, printing, and pharmaceuticals. These substances have a strong odor, irritate or damage human organs, and in severe cases, can cause poisoning or cancer, endangering human health. Furthermore, VOCs in the atmosphere can also cause problems such as photochemical smog, seriously damaging the ecological environment.

[0003] Based on principles, VOCs pollution control can be categorized into adsorption, incineration, catalytic oxidation, biological methods, and membrane separation. Among these, catalytic oxidation technology, with its advantages of cost-effectiveness and high efficiency, is one of the most promising technologies for VOCs removal. Developing high-performance, long-life catalytic oxidation catalysts is crucial for achieving waste gas purification and green production. Currently, catalytic oxidation catalysts often use honeycomb-shaped inert materials (such as cordierite) as supports, loading noble metals and / or some transition metal oxides as catalytically active components to achieve VOCs catalytic oxidation. For example, CN106890642A discloses a catalyst for treating benzene compounds in industrial waste gas and its preparation method. By sequentially coating a first catalyst layer and a second catalyst layer onto a ceramic honeycomb support, a VOCs catalytic oxidation catalyst with low ignition temperature and high conversion rate is obtained. The support used in the above report is a single-channel honeycomb support. In practical applications, this type of support suffers from problems such as short residence time of reactant gases on the catalyst surface and difficulty in fully utilizing the catalytic performance of the catalyst at high space velocities and low temperatures. Developing carrier materials with complex cross-pore structures can effectively alleviate the problem of short residence time of gas on the catalyst surface, improve the utilization efficiency of catalytic active components, and has broad application prospects.

[0004] 3D printing technology, an emerging intelligent manufacturing technology, uses computer-controlled layer-by-layer material stacking to create three-dimensional target structures. Compared to traditional processing techniques, 3D printing offers advantages such as mold-free operation, high raw material utilization, and flexible product structures, making it suitable for preparing VOCs carriers with complex porous structures. For example, Luke et al. (Journal of Water Process Engineering, 2020, 35, 101194) used 3D printing to prepare carbon black-modified polylactic acid bulk materials for removing VOC pollutants (benzene, toluene, and ethylbenzene) from water. However, this method utilizes physical adsorption to remove VOCs, and its pollutant removal capacity is limited by the saturation adsorption capacity, making it unsuitable for gas-phase VOCs treatment systems.

[0005] Ceramic 3D printing uses inorganic powders as the primary processing material and combines photopolymerization to achieve additive manufacturing. This technology holds promise for preparing ceramic support materials with high mechanical strength, good stability, and complex interconnected pores, effectively improving reactant-catalyst contact diffusion in VOCs catalytic oxidation systems and enhancing catalyst lifetime and performance. A key challenge in this field is how to utilize 3D printing technology to provide a VOCs oxidation catalyst that fully utilizes its catalytic performance at high space velocities and low temperatures. Summary of the Invention

[0006] The purpose of this invention is to provide a VOCs oxidation catalyst that can fully exert its catalytic performance at high space velocity and low temperature. Specifically, it provides a VOCs oxidation catalyst, its preparation method, and its application. The VOCs oxidation catalyst prepared by the method of this invention is rich in interconnected channels, has a large specific surface area and a high catalyst loading, and has a low catalytic temperature, enabling the catalytic oxidation of VOCs at high space velocity and low temperature.

[0007] To achieve the above objectives, a first aspect of the present invention provides a method for preparing a VOCs oxidation catalyst, the method comprising:

[0008] (1) The 3D printing paste is processed by 3D printing to obtain a preform with a hollow dot matrix structure;

[0009] (2) The preform is degreased, sintered and alkali treated to obtain a 3D printed ceramic carrier;

[0010] (3) The catalyst slurry is loaded onto the surface of the 3D printed ceramic carrier, and then dried and calcined to obtain a 3D printed ceramic carrier with a catalyst layer on the surface, which is the VOCs oxidation catalyst.

[0011] Preferably, in step (2), the alkali treatment method includes immersing the sintered carrier in an alkali solution for alkali treatment.

[0012] Preferably, in step (3), the calcination method is a two-step calcination, more preferably including: in the first stage, the temperature is increased to 250-350°C at a rate of 2-6°C / min and held for 0.5-2 hours; in the second stage, the temperature is increased to 450-550°C at a rate of 3-8°C / min and held for 1-3 hours.

[0013] A second aspect of the present invention provides a VOCs oxidation catalyst prepared according to the method described above.

[0014] A third aspect of the present invention provides a VOCs oxidation catalyst, the catalyst comprising a 3D-printed ceramic support and a catalyst layer supported on the 3D-printed ceramic support;

[0015] Among them, compared with 1L 3D printed ceramic carrier, the loading of the catalyst layer is 40-200g;

[0016] The 3D-printed ceramic carrier has a hollow dot matrix structure with a specific surface area of ​​8m². 2 The average pore size is 0.5-10 μm and the pore volume is 0.05-5 mL / g.

[0017] The fourth aspect of the present invention relates to the application of the VOCs oxidation catalyst described above in the catalytic oxidation of VOCs.

[0018] In this invention, a 3D-printed ceramic carrier containing complex interconnected channels is prepared by 3D printing, and then subjected to alkaline etching treatment. After loading a catalyst slurry onto its surface, it is calcined and stabilized to obtain a VOCs oxidation catalyst. The obtained catalyst can fully exert its catalytic performance at high space velocity and low temperature.

[0019] Furthermore, the support prepared by 3D printing in this invention has a complex, interconnected cross-pore structure, which can fully expose the catalytically active components, thereby effectively improving the utilization efficiency of the catalytically active components, and is expected to reduce the amount of (precious) metals used in the catalyst, thereby reducing costs; it can also effectively alleviate the problem of short residence time of gas on the catalyst surface and improve the reaction contact.

[0020] The VOCs oxidation catalyst prepared by the method described in this invention has a large specific surface area and a high catalyst loading, and a low catalytic temperature, enabling the catalytic oxidation of VOCs at high space velocities and low temperatures.

[0021] This invention enables the preparation of VOCs oxidation catalysts by loading catalyst layers onto 3D-printed ceramic supports using a simple loading method (such as coating). The operation is simple, suitable for mass production, and has the potential to be extended to the preparation of various fixed-bed catalytic materials, showing broad application prospects. Attached Figure Description

[0022] Figure 1 This is a cross-sectional schematic diagram of the 3D printed model structure in Example 1.

[0023] Figure 2 A photograph of the VOCs oxidation catalyst obtained in Example 1. Detailed Implementation

[0024] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0025] The first aspect of this invention provides a method for preparing a VOCs oxidation catalyst, the method comprising:

[0026] (1) The 3D printing paste is processed by 3D printing to obtain a preform with a hollow dot matrix structure;

[0027] (2) The preform is degreased, sintered and alkali treated to obtain a 3D printed ceramic carrier;

[0028] (3) The catalyst slurry is loaded onto the surface of the 3D printed ceramic carrier, and then dried and calcined to obtain a 3D printed ceramic carrier with a catalyst layer on the surface, which is the VOCs oxidation catalyst.

[0029] In this invention, the 3D printing paste can be selected from ceramic pastes commonly used in the art that can be used for 3D printing, depending on the different 3D printing mechanisms. For example, the 3D printing paste can be a photosensitive ceramic paste.

[0030] Preferably, the 3D printing paste comprises a photosensitive resin mixture and ceramic powder.

[0031] The photosensitive resin mixture can be a photosensitive resin mixture conventionally used in the art. Preferably, the photosensitive resin mixture comprises a photoinitiator, a photosensitive resin, and a powder dispersant.

[0032] Preferably, relative to 100 parts by weight of the photoinitiator mixture, the content of the photoinitiator is 0.5-10 parts by weight, for example, it can be 0.5, 1, 2, 4, 6, 8, 10 parts by weight or any range between any two values; the content of the photosensitive resin is 85-95 parts by weight, for example, it can be 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95 parts by weight or any range between any two values; and the content of the powder dispersant is 2-5 parts by weight, for example, it can be 2, 3, 4, 5 parts by weight or any range between any two values.

[0033] The photoinitiator described in this invention is a commonly used photoinitiator, wherein the effective light absorption peak of the photoinitiator is preferably 350-450 nm; more preferably, the photoinitiator is selected from at least one of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO), 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, isopropylthioxanthone (ITX), and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (819).

[0034] The photosensitive resin can be a conventional photosensitive resin in the art, preferably a mixture of acrylate prepolymer and acrylate monomer.

[0035] Preferably, the acrylate prepolymer is an epoxy acrylate prepolymer and / or a polyurethane acrylate prepolymer.

[0036] Preferably, the propylene monomer is selected from at least one of 1,6-hexanediol diacrylate (HDDA), tripropylene glycol diacrylate (TPGDA), pentaerythritol triacrylate (PETA), and trimethylolpropane triacrylate (TMPTA).

[0037] Preferably, the weight ratio of the acrylate prepolymer and the acrylate monomer mixture is 1:0.6-2.2, for example, it can be 1:0.6, 1:0.8, 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, 1:2.2, or any range between any two values.

[0038] The powder dispersant can be a commonly used dispersant. Preferably, the powder dispersant is selected from at least one of sulfate ester salts (such as sodium dodecyl sulfate and higher fatty alcohol polyoxyethylene ether sulfate), polyols (such as glycerol fatty acid esters, pentaerythritol fatty acid esters, sorbitol fatty acid esters, and dehydrated sorbitol fatty acid esters), and silane coupling agents (such as PSI-500, PSI-510, PSI520, and PSI-512 silane coupling agents).

[0039] The ceramic powder can be an aluminosilicate mineral clay, preferably selected from at least one of cordierite, kaolin, and bentonite.

[0040] Preferably, the average particle size of the ceramic powder is less than 10 micrometers, more preferably less than 5 micrometers, for example, it can be 1, 2, 3, 4, 5 micrometers or less, or any range between any two values.

[0041] Preferably, the weight ratio of the ceramic powder and the photosensitive resin mixture is 1:0.2-1.5, for example, it can be 1:0.2, 1:0.4, 1:0.6, 1:0.8, 1:1, 1:1.2, 1:1.4, 1:1.5, or any range between any two values.

[0042] Preferably, the method for preparing the 3D printing slurry includes: mixing a photosensitive resin mixture with ceramic powder and grinding them to obtain the 3D printing slurry.

[0043] During mixing, the photosensitive resin mixture can be prepared first and then mixed with the ceramic powder. Alternatively, the components in the mixture can be mixed with the ceramic powder in any order, as long as a uniformly mixed slurry is obtained. In a preferred embodiment of this invention, ceramic powder is added to the photosensitive resin mixture. During the addition of ceramic powder, a high-speed disperser can be used for stirring, with the stirring speed set to 400-650 rpm. After the ceramic powder is completely added, stirring continues for 20-60 minutes.

[0044] The initially mixed ceramic slurry can be repeatedly ground using, for example, a ball mill to obtain a 3D printing slurry.

[0045] Preferably, the grinding method is ball milling. The ball milling can be performed using a ball mill, such as a planetary ball mill (e.g., the JC-QM series vertical planetary ball mill from Juchuang Environmental Protection).

[0046] Preferably, the ball milling conditions include: 3-5 milling cycles, each milling time of 0.5-2 hours, and a rotation speed of 100-500 rpm. Since heat is generated during the milling process, to ensure normal operation of the equipment, milling is generally stopped after a period of time, and milling is resumed after the equipment has cooled down.

[0047] In this invention, conventional 3D printing methods can be used. For example, photosensitive ceramic slurry can be placed in the 3D printer's cylinder, a 3D model can be imported, and the model can be sliced ​​by a computer for 3D printing to obtain a preform with a hollow lattice structure. It should be understood that having a hollow lattice structure means that the preform has a connected channel structure.

[0048] Preferably, the hollow dot matrix structure is composed of interconnected structural units arranged periodically, and the structural unit is a regular polyhedron composed of connecting columns.

[0049] Preferably, the regular polyhedron is at least one of regular hexahedron to regular icosahedron, such as regular hexahedron, regular octahedron, regular decahedron, regular dodecahedron, regular hexahedron, or regular icosahedron.

[0050] Preferably, the side length of the regular polyhedron is 0.5-5mm (for example, it can be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5mm, or any range between any two values).

[0051] Preferably, the connecting column is composed of a thin cylindrical column with a diameter of 0.5-2mm (for example, it can be 0.5, 1, 1.5, 2mm or less, or any range between any two values) or a thin regular prism with a base length of 0.5-2mm (for example, it can be 0.5, 1, 1.5, 2mm or less, or any range between any two values).

[0052] The shape of the embryo is not particularly limited and can be any shape. Those skilled in the art can choose a suitable shape as needed, such as a cylinder, cube, cuboid, or other regular prism, etc. It should be understood that the sidewalls of the embryo can be hollow or not, that is, they can be a single surface.

[0053] Preferably, the bottom surface of the embryo is a circle with a diameter of 0.5-10cm (for example, it can be 0.5, 1, 2, 4, 6, 8, 10cm and any range between any two values) or a regular polygon with a bottom side length of 0.5-10cm (for example, it can be 0.5, 1, 2, 4, 6, 8, 10cm and any range between any two values).

[0054] Preferably, the height of the embryo is 0.5-20cm, for example, it can be 0.5, 1, 2, 4, 6, 8, 10, 15, 20cm and any range between any two values, more preferably 1-5cm.

[0055] In this invention, the 3D printing mechanism can be photopolymerization. Preferably, the 3D printing conditions include: a single-layer curing thickness of 20-150 micrometers, a single-layer illumination time of 5-20 seconds, and an illumination intensity of 2-10 mW / cm². 2 The wavelength of the light source is 350-450nm.

[0056] The 3D printing is completed using a DLP-type 3D printing device, such as the recessed DLP-3D printer (model SU136A) from Foshan Guanglei Intelligent Manufacturing Co., Ltd.

[0057] In this invention, the degreasing and sintering in step (2) can be done in a manner that is conventional in the art.

[0058] Preferably, in step (2), the degreasing method is a two-stage heat treatment.

[0059] Preferably, the degreasing method includes: a first stage of heating to 450-550℃ (e.g., 3, 4, 5, 6, 7, 8℃ / min or any range between any two values) at a rate of 3-8℃ / min, and maintaining the temperature for 1-3 hours (e.g., 1, 1.5, 2, 2.5, 3 hours or any range between any two values). The second stage involves increasing the temperature at a rate of 8-15℃ / min (e.g., 8, 9, 10, 11, 12, 13, 14, 15℃ / min or any range between any two values) to 650-750℃ (e.g., 650, 670, 690, 710, 730, 750℃ or any range between any two values), and maintaining this temperature for 1-3 hours (e.g., 1, 1.5, 2, 2.5, 3 hours or any range between any two values).

[0060] Preferably, in step (2), the sintering method is to continue heating to 950-1350℃ (for example, it can be 8, 9, 10, 11, 12, 13, 14, 15℃ / min and any range between any two values) at a rate of 8-15℃ / min (for example, it can be 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350℃ and any range between any two values) and hold for 1-3 hours (for example, it can be 1, 1.5, 2, 2.5, 3 hours and any range between any two values); then cooling to room temperature at a rate of 3-8℃ / min (for example, it can be 3, 4, 5, 6, 7, 8℃ / min and any range between any two values).

[0061] In this invention, room temperature refers to a temperature of 20-30°C.

[0062] Preferably, in step (2), the alkali treatment method includes immersing the sintered carrier in an alkali solution for alkali treatment.

[0063] Preferably, the alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution.

[0064] Preferably, the concentration of the alkaline solution is 5-20% by weight, for example, it can be 5, 10, 15, 20% by weight or any range between any two values.

[0065] Preferably, the conditions for the alkali treatment include: a temperature of 30-80℃, such as 30, 40, 50, 60, 70, 80℃ or any range between any two values; and a time of 0.5-6 hours, such as 0.5, 1, 2, 3, 4, 5, 6 hours or any range between any two values.

[0066] Preferably, the weight ratio of the sintered carrier to the alkaline solution is 1:4-10, for example, it can be 1:4, 1:6, 1:8, 1:10, or any range between any two values.

[0067] It should be understood that after alkali treatment, the 3D printed ceramic carrier can be washed to remove excess alkali, for example, by washing multiple times with deionized water. To facilitate subsequent processing, the 3D printed ceramic carrier can also be dried to remove excess water. This drying can be done by baking under conventional conditions in the art, such as baking at 80-120°C.

[0068] Preferably, the specific surface area of ​​the 3D printed ceramic carrier is 8m². 2 / g or more.

[0069] Preferably, the average pore size of the 3D printed ceramic carrier is 0.5-10 μm.

[0070] Preferably, the pore volume of the 3D printed ceramic carrier is 0.05-5 mL / g.

[0071] In step (3) of the present invention, the catalyst slurry is loaded onto the surface of the 3D printed ceramic carrier, and then dried and calcined to obtain a 3D printed ceramic carrier with a catalyst layer loaded on the surface, which is the VOCs oxidation catalyst.

[0072] In this invention, the catalyst slurry can be prepared according to conventional methods in the art.

[0073] Preferably, the catalyst slurry contains a catalyst support, an active component, and water.

[0074] The catalyst support can be a conventional catalyst support in the art, such as at least one of Al2O3 (preferably activated alumina), CeO2 and La2O3.

[0075] Preferably, the active component is Pt and / or Pd.

[0076] Preferably, in the catalyst slurry, the content of catalyst support is 15-35% by weight, the content of active component is 0.01-0.3% by weight, and the content of water is 65-85% by weight.

[0077] In a preferred embodiment of the present invention, the catalyst slurry contains Al2O3, CeO2, La2O3, Pt, Pd and water, wherein the content of Al2O3 in the catalyst slurry is 9-30% by weight, the content of CeO2 is 2-13% by weight, the content of La2O3 is 1-7% by weight, the content of Pt is 0.01-0.15% by weight, the content of Pd is 0.01-0.15% by weight, and the content of water is 65-85% by weight.

[0078] In a preferred embodiment of the present invention, the preparation method of the catalyst slurry includes: adding Al2O3, CeO2, and La2O3 powders to water, then adding 60-68% by weight of nitric acid solution to adjust the pH to no higher than 4 (preferably 3-4), and grinding to obtain a mixture; stirring the ground mixture for 1-2 hours, then adding a solution containing Pt and Pd (e.g., platinum nitrate and / or palladium nitrate solution), and continuing to stir for 1-2 hours to obtain the catalyst slurry. The grinding of the mixture is achieved by ball milling, preferably using a vibratory ball mill (such as the GZM-6 vibratory ball mill from Tianjin Shengyuan Equipment Co., Ltd.), with a milling time of 1-5 hours and a rotation speed of 500-1500 rpm. The average particle diameter in the mixture after ball milling is less than 15 μm, that is, the average particle diameter in the catalyst slurry is less than 15 μm.

[0079] Preferably, the catalyst layer contains a catalyst support and an active component.

[0080] Preferably, compared to a 1L 3D printed ceramic carrier, the loading of the catalyst layer is 40-200g, for example, it can be 40, 60, 80, 100, 120, 140, 160, 180, 200g and any range between any two values, more preferably 80-140g.

[0081] Preferably, in the catalyst layer, compared to the 1L 3D printed ceramic carrier, the content of Pt is 0.1-0.5g, the content of Pd is 0.1-0.5g, the content of Al2O3 is 35-140g, the content of CeO2 is 2-20g, and the content of La2O3 is 1-10g.

[0082] More preferably, in the catalyst layer, compared to the 1L 3D printing carrier, the content of Pt is 0.2-0.4g, the content of Pd is 0.2-0.4g, the content of Al2O3 is 55-120g, the content of CeO2 is 5-17g, and the content of La2O3 is 3-7g.

[0083] The inventors of this invention have discovered that, when coating the same type of slurry, the 3D printed ceramic carrier of this invention has a single coating amount that is 20-40% higher by weight than that of commercial through-hole carriers, and is relatively less prone to clogging under high loads.

[0084] In this invention, the catalyst slurry can be uniformly loaded onto the surface of a 3D-printed ceramic carrier by spraying, coating, or immersion. After loading, it is dried and calcined to obtain a 3D-printed ceramic carrier with a catalyst layer on its surface. For example, the 3D-printed carrier can be immersed in the catalyst slurry for 5-30 seconds for loading. It should be understood that the catalyst slurry can be loaded onto the carrier through multiple processes.

[0085] Preferably, the drying conditions include a temperature of 100-140°C and a time of 1-4 hours.

[0086] Preferably, the roasting conditions include: a temperature of 450-650℃ and a time of 2-10 hours.

[0087] Preferably, the calcination method is a two-step calcination, more preferably including: a first stage where the temperature is increased to 250-350℃ (e.g., 250, 270, 290, 310, 330, 350℃, or any range between any two values) at a rate of 2-6℃ / min (e.g., 2, 3, 4, 5, 6℃ / min, or any range between any two values), and held for 0.5-2 hours (e.g., 0.5, 1, 1.5, 2 hours, or any range between any two values). The second stage involves increasing the temperature at a rate of 3-8℃ / min (e.g., 3, 4, 5, 6, 7, 8℃ / min or any range between any two values) to 450-550℃ (e.g., 450, 470, 490, 510, 530, 550℃ or any range between any two values), and holding for 1-3 hours (e.g., 1, 1.5, 2, 2.5, 3 hours or any range between any two values).

[0088] It should be understood that, in this invention, the preferred conditions are more conducive to improving catalyst performance, reducing catalytic temperature, and improving catalytic effect.

[0089] A second aspect of the present invention provides a VOCs oxidation catalyst prepared according to the method described above.

[0090] A third aspect of the present invention provides a VOCs oxidation catalyst, the catalyst comprising a 3D-printed ceramic support and a catalyst layer supported on the 3D-printed ceramic support;

[0091] Compared to a 1L 3D printed ceramic carrier, the loading of the catalyst layer is 40-200g, for example, it can be 40, 60, 80, 100, 120, 140, 160, 180, 200g and any range between any two values, more preferably 80-140g.

[0092] The 3D-printed ceramic carrier has a hollow dot matrix structure with a specific surface area of ​​8m². 2 The pore size is above 0.5-10 μm and the pore volume is 0.05-5 mL / g.

[0093] The introduction to 3D printed ceramic carriers and catalyst layers has been described in the first part and will not be repeated here.

[0094] The fourth aspect of the present invention relates to the application of the VOCs oxidation catalyst described above in the catalytic oxidation of VOCs.

[0095] The present invention will be described in detail below through embodiments. The following embodiments will further illustrate the present invention, but are not intended to limit the present invention.

[0096] The 3D printing was completed using a recessed DLP-3D printer (model SU136A) from Foshan Guanglei Intelligent Manufacturing Co., Ltd., with a light source wavelength of 405nm.

[0097] The average diameter of the ceramic powder particles and the particles in the catalyst slurry is the equivalent volume diameter obtained by laser particle size distribution. Experimental instrument: Malvern Mastersizer 3000.

[0098] The specific surface area was measured using the low-temperature nitrogen adsorption capacity method. Experimental instrument: Micromeritics ASAP2400 static nitrogen adsorption instrument. Experimental conditions: The sample was degassed under vacuum at 1.33 Pa and 300 °C for 4 hours, then contacted with liquid nitrogen at 77 K for isothermal adsorption and desorption. Adsorption and desorption isotherms were measured, and the total specific surface area was calculated using the BET formula.

[0099] The average pore diameter and pore volume were measured using mercury intrusion porosimetry. Test instrument: AutoPore IV 9500, Micromeritics Instrument Corporation. The pore diameter is the average pore diameter (4V / A), and the pore volume is the volume of mercury entering per unit mass of material.

[0100] The activity evaluation of the toluene catalytic oxidation reaction was performed on a micro fixed-bed reactor designed and manufactured by Tianjin Pengxiang Technology Co., Ltd., equipped with an MKS Multigas 2030 infrared detector. The reaction was carried out at atmospheric pressure, with an initial temperature of 150℃, and a programmed temperature increase at a rate of 3℃ / min until complete toluene conversion. The inlet gas composition was 450ppm C7H8 / 7% O2 / N2, and the space velocity was 12000 h⁻¹. -1 .

[0101] In the following examples and comparative examples, the room temperature was 25°C.

[0102] Example 1

[0103] (1) Preparation of photosensitive resin mixture: Mix epoxy acrylate prepolymer and acrylate monomer HDDA at a weight ratio of 1:1.5 and stir thoroughly to obtain photosensitive resin. Add photoinitiator TPO and powder dispersant (Yangzhou Lida Resin Co., Ltd., LD-1241) to the mixture so that every 100 parts by weight of photosensitive resin mixture contains 5 parts of photoinitiator, 92 parts of photosensitive resin, and 3 parts of powder dispersant. Stir thoroughly to obtain photosensitive resin mixture.

[0104] (2) Preparation of photosensitive ceramic slurry: Place the photosensitive resin mixture prepared in step (1) into a high-speed disperser. Weigh the required amount of cordierite powder (Jushi Mineral Products Processing Plant, Lingshou County, Hebei Province, average particle size 4.5 micrometers) and slowly pour it into the prepared photosensitive resin mixture. During the pouring process, turn on the high-speed disperser for stirring. The stirring speed of the high-speed disperser is set to 500 rpm. After the ceramic powder is completely poured in, continue stirring for 40 minutes. The weight ratio of ceramic powder to photosensitive resin mixture in the system is 1:1. The obtained preliminarily mixed ceramic slurry is repeatedly ground 4 times using a ball mill (Juchuang Environmental Protection JC-QM series vertical planetary ball mill), with each grinding time being 1 hour and the rotation speed being 300 rpm, to obtain the photosensitive ceramic slurry for subsequent 3D printing.

[0105] (3) 3D Printing: The photosensitive ceramic slurry is placed in a material tank, a 3D model is imported, sliced, and then 3D printed to obtain a preform with a connected channel structure. The preform is a lattice structure composed of periodically arranged hollow octahedrons as the smallest structural repeating units; the side length of a single hollow octahedron is 3mm, the connecting column is a thin cylinder with a diameter of 1.2mm, the carrier is a cylinder with a base diameter of 3cm and a height of 1cm (e.g., Figure 1 and 2 (As shown). The 3D printing parameters are as follows: single-layer curing thickness 100 micrometers, single-layer illumination time 10 seconds, and illumination intensity 5 mW / cm². 2 .

[0106] (4) Degreasing and Sintering of the Preform: The printed preform was degreased and sintered using a two-stage heating process. In the first stage, the temperature was increased to 500°C at a rate of 5°C / min and held for 2 hours. In the second stage, the temperature was increased to 700°C at a rate of 10°C / min and held for 2 hours. After the degreasing process, the temperature was increased to 980°C at a rate of 10°C / min and held for 2 hours. Then, the temperature was decreased to room temperature at a rate of 5°C / min.

[0107] (5) Alkali treatment: The carrier was placed in a 6% (w / w) potassium hydroxide aqueous solution (carrier:alkali solution weight ratio 1:9) and treated at 50°C for 6 hours. The alkaline-treated carrier was rinsed three times with deionized water and dried at 110°C for later use. The specific surface area, average pore size, and pore volume of the dried carrier were measured, and the results are shown in Table 1.

[0108] (6) Catalyst slurry preparation and coating: Al2O3, CeO2, and La2O3 powders were added to deionized water, and then 63% concentrated nitric acid was added to adjust the pH to approximately 3.5. The mixture was then thoroughly ground using a vibratory ball mill (Tianjin Shengyuan Equipment Co., Ltd., GZM-6). The specific grinding conditions were: ball milling time 2.5 h, rotation speed 1000 rpm. The average particle diameter in the mixture after ball milling was 10.3 μm. After stirring the ball-milled mixture for 1 hour, platinum nitrate and palladium nitrate solutions were added, and stirring was continued for another hour to obtain the catalyst slurry. The catalyst slurry was uniformly loaded onto the surface of a 3D printed ceramic carrier to obtain a 3D printed ceramic carrier coated with the catalyst slurry.

[0109] (7) Post-treatment: The 3D-printed ceramic support coated with the catalyst slurry was dried at 120°C for 2 hours, then heated to 250°C at a rate of 3°C / min and held for 0.5 hours, and then heated to 450°C at a rate of 4°C / min and held for 1 hour to obtain the VOCs oxidation catalyst. The total coating amount of the catalyst layer on each liter of ceramic support was 60g (see Table 1), which contained 0.2g of Pt, 0.1g of Pd, 55g of activated alumina, 3g of cerium oxide, and 1.7g of lanthanum oxide.

[0110] The performance of the VOCs oxidation catalyst obtained in Example 1 was evaluated using toluene as a model compound. 50 and T 95 The conversion temperatures are shown in Table 2.

[0111] Example 2

[0112] (1) Preparation of photosensitive resin mixture: Mix polyurethane acrylate and acrylate monomer TPGDA at a weight ratio of 1:0.8 and stir thoroughly to obtain photosensitive resin. Add photoinitiator 819 and powder dispersant (Yangzhou Lida Resin Co., Ltd., LD-1800) to the mixture so that every 100 parts by weight of photosensitive resin mixture contains 3 parts of photoinitiator, 92 parts of photosensitive resin, and 5 parts of powder dispersant. Stir thoroughly to obtain photosensitive resin mixture.

[0113] (2) Preparation of photosensitive ceramic slurry: Place the photosensitive resin mixture prepared in step (1) into a high-speed disperser. Weigh the required amount of kaolin powder (Jushi Mineral Products Processing Plant, Lingshou County, Hebei Province, average particle size 2.8 micrometers) and slowly pour it into the prepared photosensitive resin mixture. During the pouring process, turn on the high-speed disperser to stir. The stirring speed of the high-speed disperser is set to 400 rpm. After the ceramic powder is completely poured in, continue stirring for 25 minutes. The weight ratio of ceramic powder to photosensitive resin mixture in the system is 1:0.5. Grind the obtained preliminarily mixed ceramic slurry repeatedly 5 times using a ball mill (Juchuang Environmental Protection JC-QM series vertical planetary ball mill), with each grinding time being 0.8 hours and a rotation speed of 450 rpm, to obtain the photosensitive ceramic slurry for subsequent 3D printing.

[0114] (3) 3D Printing: The ceramic slurry is placed in a material tank, a 3D model is imported, sliced, and then 3D printed to obtain a preform with a connected channel structure. The preform is a lattice structure composed of periodically arranged hollow dodecahedrons as the smallest structural repeating units; the side length of a single hollow dodecahedron is 1mm, the connecting pillars are composed of thin cubic prisms with a side length of 0.8mm, and the carrier is a cylinder with a base diameter of 3cm and a height of 1cm (appearance and...). Figure 2 (Similar). 3D printing parameters are as follows: single-layer curing thickness 40 micrometers, single-layer illumination time 15 seconds, illumination intensity 3 mW / cm². 2 .

[0115] (4) Degreasing and sintering of the preform: The printed preform was degreased and sintered using a two-stage heating process. In the first stage, the temperature was increased to 460°C at a rate of 3°C / min and held for 2 hours. In the second stage, the temperature was increased to 680°C at a rate of 8°C / min and held for 3 hours. After the degreasing process, the temperature was increased to 1100°C at a rate of 10°C / min and held for 2 hours. Then, the temperature was decreased to room temperature at a rate of 5°C / min.

[0116] (5) Alkali treatment: The carrier was placed in a 10% (w / w) potassium hydroxide aqueous solution (carrier:alkali weight ratio 1:6) and treated at 80°C for 2 hours. The alkaline-treated carrier was rinsed three times with deionized water and dried at 90°C for later use. The specific surface area, average pore size and pore volume of the dried carrier were measured, and the results are shown in Table 1.

[0117] (6) Catalyst slurry preparation and coating: Al2O3, CeO2, and La2O3 powders were added to deionized water, and then 63% concentrated nitric acid was added to adjust the pH to approximately 3.5. The mixture was then thoroughly ground using a vibratory ball mill (Tianjin Shengyuan Equipment Co., Ltd., GZM-6). The specific grinding conditions were: ball milling time 3 hours, rotation speed 800 rpm. The average particle diameter in the mixture after ball milling was 8.5 μm. After stirring the ball-milled mixture for 1.5 hours, platinum nitrate and palladium nitrate solutions were added, and stirring was continued for another 1.5 hours to obtain the catalyst slurry. The catalyst slurry was uniformly loaded onto the surface of a 3D printed ceramic carrier to obtain a 3D printed ceramic carrier coated with the catalyst slurry.

[0118] (7) Post-treatment: The 3D-printed ceramic support coated with the catalyst slurry was dried at 130°C for 2 hours, then heated to 320°C at a rate of 5°C / min and held for 2 hours, and then heated to 530°C at a rate of 6°C / min and held for 3 hours to obtain the VOCs catalyst. The total coating amount of the catalyst layer on each liter of ceramic support was 40g (see Table 1), which contained 0.15g of Pt, 0.2g of Pd, 32g of activated alumina, 5g of cerium oxide, and 2.65g of lanthanum oxide.

[0119] The performance of the VOCs oxidation catalyst obtained in Example 2 was evaluated using toluene as a model compound. 50 and T 95 The conversion temperatures are shown in Table 2.

[0120] Example 3

[0121] (1) Preparation of photosensitive resin mixture: Mix polyurethane acrylate and acrylate monomer TMPTA at a weight ratio of 1:2 and stir thoroughly to obtain photosensitive resin. Add photoinitiator ITX and powder dispersant (Yangzhou Lida Resin Co., Ltd., LD-1800) to the mixture so that every 100 parts by weight of photosensitive resin mixture contains 8 parts of photoinitiator, 88 parts of photosensitive resin, and 4 parts of powder dispersant. Stir thoroughly to obtain photosensitive resin mixture.

[0122] (2) Preparation of photosensitive ceramic slurry: Place the photosensitive resin mixture prepared in step (1) into a high-speed disperser. Weigh the required amount of bentonite powder (Hebei Lingshou County Jushi Mineral Products Processing Plant, average particle size 3.6 micrometers) and slowly pour it into the prepared photosensitive resin mixture. During the pouring process, turn on the high-speed disperser to stir. The stirring speed of the high-speed disperser is set to 600 rpm. After the ceramic powder is completely poured in, continue stirring for 60 minutes. The weight ratio of ceramic powder to photosensitive resin mixture in the system is 1:1.4. Grind the obtained preliminarily mixed ceramic slurry repeatedly 3 times using a ball mill (Juchuang Environmental Protection JC-QM series vertical planetary ball mill), each grinding time is 1.5 hours, and the speed is 450 rpm, to obtain the photosensitive ceramic slurry for subsequent 3D printing.

[0123] (3) 3D Printing: The ceramic slurry is placed in a material tank, a 3D model is imported, sliced, and then 3D printed to obtain a preform with a connected channel structure. The preform is a lattice structure composed of periodically arranged hollow icosahedrons as the smallest structural repeating units; the side length of a single hollow icosahedron is 4mm, the connecting column is a thin cylinder with a diameter of 1.8mm, and the overall outline of the carrier is cylindrical with a base diameter of 3cm and a height of 1cm (appearance and...). Figure 2 (Similar). 3D printing parameters are as follows: single-layer curing thickness 125 micrometers, single-layer illumination time 15 seconds, illumination intensity 8 mW / cm². 2 .

[0124] (4) Degreasing and sintering of the preform: The printed preform was degreased and sintered using a two-stage heating process. In the first stage, the temperature was increased to 530°C at a rate of 7°C / min and held for 2 hours. In the second stage, the temperature was increased to 720°C at a rate of 12°C / min and held for 2.5 hours. After the degreasing process, the temperature was increased to 1300°C at a rate of 10°C / min and held for 1.5 hours. Then, the temperature was decreased to room temperature at a rate of 5°C / min.

[0125] (5) Alkali treatment: The carrier was placed in an 18% (w / w) sodium hydroxide aqueous solution (carrier:alkali weight ratio 1:5) and treated at 40°C for 1 hour. The alkaline-treated carrier was rinsed three times with deionized water and dried at 100°C for later use. The specific surface area, average pore size, and pore volume of the dried carrier were measured, and the results are shown in Table 1.

[0126] (6) Catalyst slurry preparation and coating: Al2O3, CeO2, and La2O3 powders were added to deionized water, and then 63% concentrated nitric acid was added to adjust the pH to approximately 3.5. The mixture was then thoroughly ground using a vibratory ball mill (Tianjin Shengyuan Equipment Co., Ltd., GZM-6). The specific grinding conditions were: ball milling time 1.5 h, rotation speed 1200 rpm. The average particle diameter in the mixture after ball milling was 12.5 μm. After stirring the ball-milled mixture for 2 hours, platinum nitrate and palladium nitrate solutions were added, and stirring was continued for another 2 hours to obtain the catalyst slurry. The catalyst slurry was uniformly loaded onto the surface of a 3D printed ceramic carrier to obtain a 3D printed ceramic carrier coated with the catalyst slurry.

[0127] (7) Post-treatment: The 3D-printed ceramic support coated with the catalyst slurry was dried at 130°C for 2 hours, then heated to 350°C at a rate of 6°C / min and held for 2 hours, and then heated to 550°C at a rate of 7°C / min and held for 3 hours to obtain the VOCs oxidation catalyst. The total coating amount of the catalyst layer on each liter of ceramic support was 120g (see Table 1), which contained 0.3g of Pt, 0.4g of Pd, 100g of activated alumina, 15g of cerium oxide, and 4.3g of lanthanum oxide.

[0128] The performance of the VOCs oxidation catalyst obtained in Example 3 was evaluated using toluene as a model compound. 50 and T 95 The conversion temperatures are shown in Table 2.

[0129] Example 4

[0130] Example 4 uses a single-stage calcination process. After drying the 3D printed ceramic carrier coated with catalyst slurry, it is heated to 550°C at a rate of 5°C / min and calcined for 2 hours to obtain a VOCs oxidation catalyst. Other conditions are the same as in Example 1.

[0131] The specific surface area, average pore size, and pore volume of the obtained support, as well as the total coating amount of the catalyst layer, are shown in Table 1. The performance of the obtained VOCs oxidation catalyst was evaluated using toluene as a model compound. 50 and T 95 The conversion temperatures are shown in Table 2.

[0132] Example 5

[0133] In Example 5, the total coating amount of catalyst layer on each liter of ceramic support was 60g, which contained 0.15g of Pt, 0.15g of Pd, 30g of activated alumina, 15g of cerium oxide, and 14.7g of lanthanum oxide. Other conditions were the same as in Example 1.

[0134] The specific surface area, average pore size, and pore volume of the obtained support, as well as the total coating amount of the catalyst layer, are shown in Table 1. The performance of the obtained VOCs oxidation catalyst was evaluated using toluene as a model compound. 50 and T 95 The conversion temperatures are shown in Table 2.

[0135] Comparative Example 1

[0136] Comparative Example 1 did not perform alkaline etching on the carrier, i.e., step (5) was not performed, and other conditions were the same as in Example 1.

[0137] The specific surface area, average pore size, and pore volume of the obtained support, as well as the total coating amount of the catalyst layer, are shown in Table 1. The performance of the obtained VOCs oxidation catalyst was evaluated using toluene as a model compound. 50 and T 95 The conversion temperatures are shown in Table 2.

[0138] Comparative Example 2

[0139] Comparative Example 2 was operated according to the method described in Example 1, except that a honeycomb carrier with a single straight channel was prepared by 3D printing. The internal honeycomb structure had a wall thickness of 1.2 mm, an inner diameter of 2 mm for the square hole, and a cylindrical shape with a bottom diameter of 3 cm and a height of 1 cm.

[0140] The specific surface area, average pore size, and pore volume of the obtained support, as well as the total coating amount of the catalyst layer, are shown in Table 1. The performance of the obtained VOCs oxidation catalyst was evaluated using toluene as a model compound. 50 and T 95 The conversion temperatures are shown in Table 2.

[0141] Comparative Example 3

[0142] Comparative Example 3 uses a custom-made commercial cordierite carrier (Jiangxi Guoci Environmental Protection Technology Co., Ltd., ceramic honeycomb carrier) with a bulk density of 0.5 kg / L and a pore volume of 0.5 mL / g. It has a single cubic column straight channel inside. It is cut into a cylinder with the same dimensions as the example (bottom diameter 3 cm, height 1 cm), and then the same as Example 1 is followed from step (5).

[0143] The specific surface area, average pore size, and pore volume of the obtained support, as well as the total coating amount of the catalyst layer, are shown in Table 1. The performance of the obtained VOCs oxidation catalyst was evaluated using toluene as a model compound. 50 and T 95 The conversion temperatures are shown in Table 2.

[0144] Comparative Example 4

[0145] Comparative Example 4 follows the material ratio in Example 1, mixing the catalyst layer slurry with 3D printing ink in advance, and then printing and demolding. No alkali treatment or catalyst layer coating is performed, and other conditions are the same as in Example 1.

[0146] The performance of the obtained VOCs oxidation catalyst was evaluated using toluene as a model compound. 50 and T 95 The conversion temperatures are shown in Table 2.

[0147] Comparative Example 5

[0148] Comparative Example 5 used a custom-made commercial cordierite VOCs oxidation catalyst (precious metal Pt content 0.4 g / L) with a single cubic columnar straight channel inside; it was cut into cylinders of the same size as the example (3 cm in diameter at the bottom and 1 cm in height) for activity evaluation.

[0149] The performance of the obtained VOCs oxidation catalyst was evaluated using toluene as a model compound. 50 and T 95 The conversion temperatures are shown in Table 2.

[0150] Table 1

[0151]

[0152] As shown in Table 1, the specific surface area of ​​the support and the total coating amount of the catalyst layer obtained in the embodiments of the present invention are both higher than those in Comparative Examples 1-4. Compared with Comparative Examples 1-3, the support material prepared by the present invention is more conducive to increasing the coating amount of the catalytic catalyst layer, which will help improve its degradation efficiency for pollutants such as VOCs.

[0153] Table 2

[0154] serial number <![CDATA[T 50 (℃)]]> <![CDATA[T 95 (℃)]]> Example 1 211.0 232.8 Example 2 215.5 238.6 Example 3 209.6 225.1 Example 4 217.4 240.2 Example 5 220.3 243.6 Comparative Example 1 218.5 241.2 Comparative Example 2 225.6 251.1 Comparative Example 3 227.9 253.1 Comparative Example 4 >400 >500 Comparative Example 5 236.3 267.2

[0155] As can be seen from Table 2, the VOCs catalytic materials T obtained in Examples 1-4 of the present invention 50 and T 95 The conversion temperatures were all lower than those of the comparative example. Compared to the comparative example, the VOCs catalytic material prepared in this invention has a higher efficiency in pollutant degradation and is expected to be widely applied in the preparation of various fixed-bed catalytic materials, showing broad application prospects.

[0156] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a VOCs oxidation catalyst, characterized in that, The method includes: (1) The 3D printing paste is processed by 3D printing to obtain a preform with a hollow dot matrix structure; (2) The preform is degreased, sintered and alkali treated to obtain a 3D printed ceramic carrier; (3) The catalyst slurry is loaded onto the surface of the 3D printed ceramic carrier, and then dried and calcined to obtain a 3D printed ceramic carrier with a catalyst layer on the surface, which is the VOCs oxidation catalyst. The 3D printing paste contains a mixture of photosensitive resin and ceramic powder; The photosensitive resin mixture contains a photoinitiator, a photosensitive resin, and a powder dispersant; Relative to 100 parts by weight of photoinitiator, the content of photoinitiator is 0.5-10 parts by weight, the content of photosensitive resin is 85-95 parts by weight, and the content of powder dispersant is 2-5 parts by weight. The alkaline treatment method includes immersing the sintered carrier in an alkaline solution for alkaline treatment. The conditions for the alkali treatment include: a temperature of 30-80℃ and a time of 0.5-6 hours; The hollowed-out dot matrix structure is composed of interconnected structural units arranged periodically, and each structural unit is a regular polyhedron composed of connecting columns; Wherein, the regular polyhedron is at least one of regular hexahedron to regular icosahedron; The side length of the regular polyhedron is 0.5-5 mm; The connecting column is composed of thin cylindrical columns with a diameter of 0.5-2 mm or thin regular prisms with a base length of 0.5-2 mm spliced ​​together.

2. The method according to claim 1, wherein, The weight ratio of the ceramic powder and photosensitive resin mixture is 1:0.2-1.5; and / or The effective light absorption peak of the photoinitiator is 350-450 nm; and / or The photosensitive resin is a mixture of acrylate prepolymer and acrylate monomer; and / or The powder dispersant is selected from at least one of sulfate ester salts, polyols, and silane coupling agents; and / or The ceramic powder is an aluminosilicate mineral clay; and / or The alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution; The weight ratio of the sintered carrier to the alkaline solution is 1:4-10.

3. The method according to claim 2, wherein, The photoinitiator is selected from at least one of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, isopropylthioxanthrone, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; and / or The acrylate prepolymer is an epoxy acrylate prepolymer and / or a polyurethane acrylate prepolymer; and / or The ceramic powder is selected from at least one of cordierite, kaolin, and bentonite; and / or The concentration of the alkaline solution is 5-20% by weight.

4. The method according to claim 3, wherein, The acrylate monomers are selected from at least one of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, pentaerythritol triacrylate, and trimethylolpropane triacrylate; and / or The weight ratio of the acrylate prepolymer to the acrylate monomer mixture is 1:0.6-2.2; and / or The average particle size of the ceramic powder is less than 10 micrometers.

5. The method according to any one of claims 1-4, wherein, The method for preparing the 3D printing paste includes: mixing a photosensitive resin mixture with ceramic powder and grinding them to obtain the 3D printing paste.

6. The method according to claim 5, wherein, The grinding method is ball milling.

7. The method according to claim 6, wherein, The conditions for ball milling include: 3-5 milling cycles, 0.5-2 hours for each milling cycle, and a rotation speed of 100-500 rpm.

8. The method according to claim 1, wherein, The conditions for 3D printing include: a single-layer curing thickness of 20-150 micrometers, a single-layer illumination time of 5-20 seconds, and an illumination intensity of 2-10 mW / cm². 2 The wavelength of the light source is 350-450nm.

9. The method according to claim 1, wherein, In step (2), the degreasing method is a two-stage heat treatment; and / or In step (2), the sintering method is to continue heating to 950-1350℃ at a rate of 8-15℃ / min and hold for 1-3 hours; then cool down to room temperature at a rate of 3-8℃ / min.

10. The method according to claim 9, wherein, The degreasing method includes: in the first stage, the temperature is increased to 450-550 ℃ at a rate of 3-8 ℃ / min and held for 1-3 hours; in the second stage, the temperature is further increased to 650-750 ℃ ​​at a rate of 8-15 ℃ / min and held for 1-3 hours.

11. The method according to claim 1, wherein, In step (3), the catalyst layer contains a catalyst support and an active component.

12. The method according to claim 11, wherein, The catalyst support is at least one of Al2O3, CeO2, and La2O3; and / or The active component is Pt and / or Pd; and / or Compared to a 1L 3D-printed ceramic carrier, the catalyst layer has a loading of 40-200g; and / or In the catalyst layer, compared to the 1L 3D printed ceramic carrier, the content of Pt is 0.1-0.5g, the content of Pd is 0.1-0.5g, the content of Al2O3 is 35-140g, the content of CeO2 is 2-20g, and the content of La2O3 is 1-10g.

13. The method according to claim 12, wherein, Compared to a 1L 3D-printed ceramic carrier, the catalyst layer has a loading of 80-140g; and / or In the catalyst layer, compared to the 1L 3D printing carrier, the content of Pt is 0.2-0.4g, the content of Pd is 0.2-0.4g, the content of Al2O3 is 55-120g, the content of CeO2 is 5-17g, and the content of La2O3 is 3-7g.

14. The method according to claim 1, wherein, In step (3), the drying conditions include: a temperature of 100-140°C and a time of 1-4 hours; and / or The roasting conditions include a temperature of 450-650℃ and a time of 2-10 hours.

15. The method according to claim 14, wherein, The roasting method is a two-step roasting process.

16. The method according to claim 15, wherein, The roasting method includes: in the first stage, the temperature is increased to 250-350 ℃ at a rate of 2-6 ℃ / min and held for 0.5-2 hours; in the second stage, the temperature is further increased to 450-550 ℃ at a rate of 3-8 ℃ / min and held for 1-3 hours.

17. The VOCs oxidation catalyst prepared by the method according to any one of claims 1-16.

18. A VOCs oxidation catalyst, characterized in that, The catalyst comprises a 3D-printed ceramic support and a catalyst layer supported on the 3D-printed ceramic support; Among them, compared with a 1L 3D printed ceramic carrier, the loading of the catalyst layer is 40-200g; The 3D-printed ceramic carrier has a hollow lattice structure with a specific surface area of ​​8 m². 2 The average pore size is 0.5-10 μm and the pore volume is 0.05-5 mL / g. The hollowed-out dot matrix structure is composed of interconnected structural units arranged periodically, and each structural unit is a regular polyhedron composed of connecting columns. Wherein, the regular polyhedron is at least one of regular hexahedron to regular icosahedron; The side length of the regular polyhedron is 0.5-5 mm; The connecting column is composed of thin cylindrical columns with a diameter of 0.5-2 mm or thin regular prisms with a base length of 0.5-2 mm spliced ​​together.

19. The VOCs oxidation catalyst according to claim 18, wherein, The catalyst layer contains a catalyst support and an active component.

20. The VOCs oxidation catalyst according to claim 19, wherein, The catalyst support is at least one of Al2O3, CeO2, and La2O3; and / or The active component is Pt and / or Pd.

21. The VOCs oxidation catalyst according to claim 20, wherein, In the catalyst layer, compared to the 1L 3D printed ceramic carrier, the content of Pt is 0.1-0.5g, the content of Pd is 0.1-0.5g, the content of Al2O3 is 35-140g, the content of CeO2 is 2-20g, and the content of La2O3 is 1-10g.

22. The use of the VOCs oxidation catalyst according to any one of claims 17-21 in the catalytic oxidation of VOCs.

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