Method for preparing manganese-based catalyst by 3D printing and catalyst prepared thereby and use thereof

Abstract

The present application relates to the field of 3D printing and catalytic materials, and discloses a method for preparing a manganese-based catalyst by 3D printing, and a catalyst prepared by the method and application of the catalyst, the method comprising the following steps: (1) mixing a photosensitive resin mixed solution and ceramic powder to obtain a photosensitive ceramic slurry, and performing 3D printing to obtain a printing blank; (2) performing debinding and sintering on the printing blank to obtain a 3D printed ceramic carrier; (3) coating a slurry containing manganese oxide on the surface of the 3D printed ceramic carrier, and calcining to obtain a manganese-based catalyst. The method realizes effective preparation of the manganese-based catalyst by coating, and the coating method is simple to operate and suitable for batch production. The carrier prepared by the 3D printing method has a connected pore structure, and the active component is fully distributed on the surface of the carrier, thereby improving the catalytic oxidation activity of the catalyst.

Description

Technical Field

[0001] This invention relates to the field of 3D printing and catalytic materials, specifically to a method for preparing manganese-based catalysts by 3D printing, the resulting catalysts, and their applications. Background Technology

[0002] PM 2.5 O3 pollution control remains a significant challenge in addressing the complex regional air pollution problem in my country. Volatile organic compounds (VOCs) are a class of organic compounds with a saturated vapor pressure higher than 133.32 Pa and a boiling point between 50-250℃. VOCs have become the second most significant air pollution problem after NO. x The key factors that will hinder further improvement in air quality make emission control of these factors an urgent priority.

[0003] In the control of VOCs emissions from industrial sources, catalytic oxidation is one of the most promising methods. Compared with traditional adsorption and absorption methods, it significantly reduces secondary pollution. Catalytic oxidation can significantly lower the oxidation temperature of VOCs, reduce the formation of by-products, and reduce energy consumption. Developing high-performance, low-cost, and long-life VOCs oxidation catalysts is key to this technology. Currently, most industrial VOCs oxidation catalysts use honeycomb-supported monolithic catalytic materials, typically using inert materials such as honeycomb cordierite or honeycomb ceramics as supports, coupled with rare earth or transition metal oxide coatings, and using noble metals such as Pt and Pd as the main active components. CN106890642B discloses a catalyst for treating benzene compounds in industrial waste gas and its preparation method, which lowers the ignition temperature of the VOCs oxidation reaction by coating the active components twice on a honeycomb ceramic support. While the aforementioned inventions can improve catalyst performance under test conditions, both honeycomb cordierite and ceramic supports are one-dimensional array pore structures. In actual operating conditions, uneven flue gas distribution and insufficient flue gas residence time lead to insufficient VOCs treatment efficiency or the need to increase catalyst loading at high space velocities. Therefore, improving the traditional one-dimensional array honeycomb pore structure is key to solving this problem, as it can improve flue gas distribution uniformity, increase flue gas residence time, reduce costs, and improve efficiency.

[0004] 3D printing technology is a new type of intelligent manufacturing technology that makes three-dimensional target structures by computer-controlled material stacking. Compared with traditional material processing technology, 3D printing is not limited by molds, and has the characteristics of high raw material utilization, strong structure design, and high flexibility of structure adjustment, which is an ideal method for designing three-dimensional cross-linked channel carrier materials. Hajimirzaee et al. confirmed by computational fluid dynamics analysis that 3D printing carriers significantly improve the degree of air flow turbulence, and significantly increase the turbulence / mass transfer and surface area (Fuel, 2020, 274:117848), which shows that 3D printing carriers have outstanding application potential in the field of VOCs catalytic oxidation. However, the carrier materials obtained by 3D printing often need to be sintered at high temperature to improve their high mechanical strength, thereby improving the service life of the related regular catalytic materials, and the sintering process usually reduces the specific surface area of the carrier material, which is not conducive to improving the catalyst loading. This defect still needs to be overcome.

[0005] On the other hand, mature commercial noble metal catalysts have always limited their further use in the industry due to their high cost, and the development of high-performance, low-cost alternative materials has become an urgent need. Manganese-based catalysts have received widespread attention from academia and industry due to their economy and excellent redox properties, and have shown excellent VOCs oxidation performance comparable to or even better than noble metal catalysts, showing broad application prospects (Chemical Review, 2019, 119(7):4471-4568). However, there are still problems of limited loading of manganese-based active components on the carrier and limited catalytic oxidation activity, so a catalyst preparation method is needed that can effectively improve the loading of manganese-based active components on the catalyst and improve the catalytic oxidation activity of the catalyst. SUMMARY

[0006] The purpose of the present application is to overcome the problems of limited loading of manganese-based active components on conventional carriers, single pore structure of the prepared catalyst carrier, which is not conducive to the diffusion of reactants in the catalytic oxidation process, and contact limitation between reactants and active components, thereby affecting the catalytic oxidation activity of the catalyst. A method for preparing a manganese-based catalyst by 3D printing and the catalyst prepared and its application are provided. The method realizes the preparation of a manganese-based catalyst by coating, loads manganese oxide with strong redox properties onto a carrier with a connected channel structure, and the coating method is simple to operate. The catalytic oxidation activity of the catalyst is improved by the combination of manganese-based active components and the carrier during the preparation process.

[0007] In order to achieve the above-mentioned purpose, the first aspect of the present application provides a method for preparing a manganese-based catalyst by 3D printing, wherein the method comprises the following steps:

[0008] (1) mixing the photosensitive resin mixed solution with the ceramic powder to obtain a photosensitive ceramic slurry, and performing 3D printing to obtain a printing blank;

[0009] (2) performing debinding and sintering on the printing blank to obtain a 3D printed ceramic carrier;

[0010] (3) coating a slurry containing manganese oxide on the surface of the 3D printed ceramic carrier, and baking to obtain a manganese-based catalyst.

[0011] Preferably, in step (2), the debinding of the printing blank is divided into two stages: the first stage is to heat at a rate of 3-8℃ / min to 450-550℃, and keep for 0.5-4h, preferably to heat at a rate of 3-7℃ / min to 460-530℃, and keep for 1-3h;

[0012] The second stage is to continue heating at a rate of 8-15℃ / min to 650-750℃, and keep for 1-3h, preferably to heat at a rate of 8-12℃ / min to 680-720℃, and keep for 2-3h.

[0013] Preferably, in step (3), the 3D printed ceramic carrier before coating is also subjected to alkali treatment, and the alkali treatment process comprises: immersing the 3D printed ceramic carrier in an alkali solution at 30-80℃ for 0.5-10h, preferably for 1-6h.

[0014] Preferably, in step (3), the total coating amount of the slurry containing manganese oxide on the 3D printed ceramic carrier per liter is 40-160g, preferably 50-130g.

[0015] The second aspect of the present application provides a manganese-based catalyst prepared by the method of the first aspect.

[0016] Preferably, the manganese-based catalyst comprises a carrier and manganese oxide coated on the surface of the carrier.

[0017] Preferably, the specific surface area of the carrier of the manganese-based catalyst is 6-20m 2 / g, preferably 8-15m 2 / g.

[0018] Preferably, the specific surface area of the manganese oxide coated on the surface of the manganese-based catalyst is 10-80m 2 / g, preferably 20-60m 2 / g.

[0019] The third aspect of the present application provides an application of the manganese-based catalyst of the second aspect in catalytic oxidation reaction.

[0020] Through the above technical solution, the following beneficial effects are obtained:

[0021] (1) In the present application, the ceramic carrier is prepared by 3D printing, a carrier with three-dimensional interconnected pores and vertical staggered structure is obtained, and a slurry containing manganese oxide is coated on the surface of the carrier. Since manganese oxide has strong oxidation and reduction properties, it can improve the utilization efficiency of the catalytic active component of the prepared catalyst and improve the catalytic oxidation activity of the catalyst.

[0022] (2) In the present application, preferably, the ceramic carrier prepared by 3D printing has a rich pore structure, which can fully expose the catalytic active component, effectively alleviate the problems of uneven gas flow distribution and insufficient residence time of reactants in the catalyst pores, and improve the reaction contact conditions. When performing VOCs catalytic oxidation reaction, it has a high conversion rate.

[0023] (3) In the present application, preferably, the preparation of the monolithic manganese-based catalyst is realized by coating on the 3D printed ceramic carrier, which is simple to operate, and the manganese-based active component is uniformly loaded on the surface of the carrier. The use of manganese oxide instead of noble metal can reduce the cost of the catalyst and is suitable for mass production. It is expected to be popularized in the preparation of various fixed-bed catalytic materials and has broad application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a schematic diagram of the 3D printing model structure of Example 1.

[0025] Figure 2 It is a physical photo of the manganese-based catalyst of Example 1.

[0026] Figure 3 It is a catalytic oxidation propane conversion-temperature relationship graph of Examples 1-6 and Comparative Examples 1-4. DETAILED DESCRIPTION

[0027] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The ranges or values should be construed to be approximations that allow for significant variation. Various ranges of values that are explicitly delineated in this specification are included in the disclosure as potentially useful in various combinations, together with individual values specified, as potentially useful in various combinations, and ranges between other stated or implied endpoints.

[0028] The first aspect of the present application provides a method for preparing a manganese-based catalyst by 3D printing, wherein the method comprises the following steps:

[0029] (1) mixing a photosensitive resin mixed solution and a ceramic powder to obtain a photosensitive ceramic slurry, and performing 3D printing to obtain a printing blank;

[0030] (2) debinding and sintering the printing blank to obtain a 3D printed ceramic carrier;

[0031] (3) coating the slurry containing manganese oxide on the surface of the 3D-printed ceramic carrier to obtain the manganese-based catalyst after calcination.

[0032] In the present application, the 3D-printed carrier is combined with the manganese-based active component, the slurry containing manganese oxide is coated on the surface of the 3D-printed ceramic carrier, the manganese-based active component is uniformly loaded on the surface of the carrier, and the manganese-based catalyst is obtained after calcination and stabilization treatment. Since the manganese oxide has strong redox property, it can not only improve the limitation of the one-dimensional array honeycomb channel structure of the traditional monolithic catalyst, but also effectively improve the diffusion and contact limitation of the reactants in the catalytic oxidation reaction, thereby improving the catalytic performance.

[0033] According to the present application, preferably, the photosensitive resin mixed solution comprises 0.5-10 parts of a photoinitiator, 85-95 parts of a photosensitive resin and 2-10 parts of a powder dispersant, preferably, the photosensitive resin mixed solution comprises 3-8 parts of a photoinitiator, 88-92 parts of a photosensitive resin and 3-5 parts of a powder dispersant, based on 100 parts of the mass of the photosensitive resin mixed solution.

[0034] In the present application, the photosensitive resin mixed solution is obtained by uniformly mixing the photoinitiator, the photosensitive resin and the powder dispersant, and the mixing mode is not particularly limited, and those skilled in the art can adjust it according to the needs, as long as a uniformly mixed photosensitive resin mixed solution can be obtained.

[0035] According to the present application, the photoinitiator can be a conventional photoinitiator in the art, and preferably, the photoinitiator is at least one selected from 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide (photoinitiator TPO), phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide (photoinitiator 819) and isopropyl thioxanthone (ITX).

[0036] According to the present application, the specific composition of the photosensitive resin has a wide selection range, and can be selected according to conventional technical means in the art. Preferably, the photosensitive resin is a mixture of acrylate prepolymers and acrylate monomers, and the acrylate prepolymers are epoxy acrylate prepolymers and / or polyurethane acrylate prepolymers.

[0037] In the present application, the acrylate monomer can be a conventional acrylate monomer in the art, and preferably, at least one selected from 1,6-hexanediol diacrylate (HDDA), tripropyleneglycol diacrylate (TPGDA) and trimethylolpropane triacrylate (TMPTA).

[0038] In the present application, the powder dispersant is a commonly used commercial dispersant, and preferably, at least one selected from sulfates, polyol powder dispersants, polyurethane powder dispersants and silane coupling agent powder dispersants.

[0039] According to the present application, preferably, the mass ratio of the acrylate pre-polymer and the acrylate monomer in the photosensitive resin is 1:0.6-2.2, for example, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, 1:2.2, and any range consisting of any two values therebetween, preferably 1:0.8-2.

[0040] According to the present application, preferably, in step (1), the mass ratio of the photosensitive resin and the ceramic powder mixture is 1:0.1-2, for example, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.8, 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, and any range consisting of any two values therebetween, preferably 1:0.2-1.6. The photosensitive ceramic slurry obtained by mixing according to the above mass ratio has a fast solidification speed during subsequent 3D printing, and the structure stability of the carrier material obtained after sintering is better.

[0041] In the present application, the mixing method of the photosensitive resin mixture and the ceramic powder is not particularly limited, and the photosensitive ceramic slurry can be obtained by uniformly mixing the photosensitive resin mixture and the ceramic powder. According to a preferred embodiment of the present application, the photosensitive resin mixture is placed in a high-speed disperser, and the ceramic powder is slowly poured in, and stirring is performed by starting the high-speed disperser during the process, and the stirring rate is 400-650 rpm / min. After the ceramic powder is completely poured in, the stirring is continued for 20-60 min to obtain the preliminarily mixed photosensitive ceramic slurry. The above slurry is repeatedly ground in a ball mill for 3-5 times, and each grinding time is 0.5-2 h, and the rotating speed is 100-500 rpm, and the photosensitive ceramic slurry is obtained by grinding.

[0042] In the present application, the type of the ball mill is not particularly limited, and it can be a conventional ball mill in the art. Preferably, a planetary ball mill is used.

[0043] According to the present application, preferably, the ceramic powder is a silicate natural mineral clay, and it is preferably selected from at least one of cordierite, kaolin, and bentonite.

[0044] According to the present application, the average particle size of the ceramic powder is not particularly limited, and preferably, the average particle size of the ceramic powder is less than 10 μm, and preferably 2.5-5 μm. The use of the ceramic powder with an average particle size less than 10 μm is more conducive to uniformly mixing the photosensitive resin mixture and the ceramic powder, and the photosensitive ceramic slurry obtained thereby has better dispersibility, and the solidification speed is fast during 3D printing, and the production efficiency is high. If the ceramic powder has a larger particle size, the uniformity thereof can be further improved by subsequent ball milling.

[0045] In the present application, the printing blank is prepared by 3D printing, a three-dimensional structure is designed by using modeling software, the photosensitive ceramic slurry is placed in the 3D printer cylinder, the three-dimensional model is imported, and the 3D printing is carried out after the computer slicing to obtain the printing blank with a connected channel structure.

[0046] In the present application, preferably, a three-dimensional structure is designed by using modeling software selected from SolidWorks, 3DMAX, AutoCAD or Materialise Magics.

[0047] According to the present application, preferably, the conditions of the 3D printing include: single layer solidification thickness 20-150 μm, single layer light irradiation time 5-20 s, light irradiation intensity 2-10 mW / cm 2 .

[0048] In the present application, the "printing blank" is a general term for the prepared blanks, and the printing method can be used to customize complex three-dimensional structures suitable for different scenes, which does not depend on the mold and does not need complex post-processing of the carrier. Compared with the traditional carrier processing method, the connected channel structure of the carrier is simple and controllable, has good regularity, and has high raw material utilization rate, and the structure can be flexibly adjusted.

[0049] In the present application, the size and structure of the printing blank are not particularly limited, and those skilled in the art can appropriately select according to the specific application scene of the prepared catalyst. The present application subsequently provides a specific preferred embodiment applied to a catalytic oxidation catalyst, and the present application is not limited thereto.

[0050] The present application does not particularly limit the connected channel structure, which has the conventional interpretation in the art. In the present application, the connected channel structure refers to the intersection and communication between the vertical and horizontal channels of the printing blank, which has good permeability, and the distribution of the channels is not particularly limited, and those skilled in the art can adaptively select according to the specific catalyst preparation. The distribution of the channels can be uniform, symmetric or non-uniform, asymmetric. According to a preferred embodiment of the present application, the specific channel structure is as shown in Figure 1 and Figure 2 .

[0051] According to the present application, preferably, the printing blank has a vertical staggered structure composed of cubic columns with a bottom side length of 0.5-2 mm. The printing blank with the above structure is processed as a carrier to prepare a manganese-based catalyst, which can effectively alleviate the problems of uneven airflow distribution and insufficient residence time of raw materials in the catalyst channels, and improve the reaction contact conditions.

[0052] In the present application, the vertical staggered has the conventional interpretation in the art, which refers to the structure perpendicular to each other formed by the overlapping of the cubic columns, such asFigure 1 Cuboid refers to a column with two equal square bases and sides perpendicular to the bases. Side length refers to the length of the side of the base of the cuboid.

[0053] According to the present application, the debinding process of the printing green body is not particularly limited, and those skilled in the art can make adaptive adjustments according to the debinding of the printing green body, as long as the organic matter in the green body is removed to allow the inorganic material to solidify into a ceramic material. Preferably, the debinding process of the printing green body comprises heating at a temperature of 400-800℃ for 1-10h.

[0054] Further preferably, in step (2), the debinding process of the printing green body comprises:

[0055] The first stage is to increase the temperature at a rate of 3-8℃ / min to 450-550℃, and maintain for 0.5-4h, preferably at a rate of 3-7℃ / min to 460-530℃, and maintain for 1-3h;

[0056] The second stage is to continue to increase the temperature at a rate of 8-15℃ / min to 650-750℃, and maintain for 1-3h, preferably at a rate of 8-12℃ / min to 680-720℃, and maintain for 2-3h.

[0057] In the present application, preferably, the debinding is divided into two stages, the first stage controls a lower heating temperature and a slower heating rate, which can remove the organic matter in the printing green body while maintaining the structure of the green body from being damaged, and the heating rate is controlled at 3-8℃ / min to avoid cracks in the green body due to rapid heating. The second stage increases the heating temperature to allow the inorganic material in the printing green body to solidify into porcelain.

[0058] According to the present application, preferably, the sintering conditions comprise a sintering temperature of 1300-1600℃, preferably 1350-1500℃; a sintering time of 1-3h, preferably 1.5-2.5h; and a heating rate of 8-15℃ / min, preferably 9-12℃ / min. In the present application, under the above sintering conditions, the obtained 3D printed ceramic carrier has high mechanical strength and large specific surface area, providing support for subsequent coating of slurry containing manganese oxide while loading more active components.

[0059] According to the present application, preferably, after sintering, the cooling rate is 3-8℃ / min, preferably 4-6℃ / min.

[0060] According to the present application, preferably, in step (3), the 3D printed ceramic carrier before coating is further subjected to an alkali treatment, and the alkali treatment process comprises immersing the 3D printed ceramic carrier in an alkali solution at 30-80℃ for 0.5-10h, preferably 1-6h.

[0061] In the present application, the alkali treatment helps to expand the specific surface area of the carrier to form a three-dimensional through-pore structure, and a slurry containing manganese oxide is coated on the carrier after alkali treatment to prepare a manganese-based catalyst, the carrier with a three-dimensional through-pore structure combined with the manganese-based active component can accelerate the diffusion of reactants in the catalytic oxidation reaction, and the catalytic oxidation reaction activity of the catalyst is significantly improved.

[0062] According to the present application, preferably, the alkali solution is an aqueous solution of NaOH and / or KOH, and the mass fraction of NaOH and / or KOH is 4%-20%, preferably 6-18%.

[0063] According to the present application, preferably, the mass ratio of the 3D printed ceramic carrier to the alkali solution is 1:4-10, preferably 1:5-9.

[0064] According to the present application, preferably, the specific surface area of the 3D printed ceramic carrier after alkali treatment is 6-20m 2 / g, preferably 8-15m 2 / g.

[0065] In the present application, the specific surface area of the 3D printed ceramic carrier after alkali treatment is measured by a low-temperature nitrogen adsorption capacity method, and the test instrument is an ASAP2400 static nitrogen adsorption instrument of Micromeritics Company. The test conditions are that the sample is vacuum degassed at 1.33Pa and 300℃ for 4h, then contacted with liquid nitrogen at 77K, and the adsorption and desorption isotherms are measured by isothermal adsorption and desorption, and the specific surface area is calculated by BET formula.

[0066] In the present application, preferably, the step of washing and drying the 3D printed ceramic carrier after alkali treatment is further included, and the washing and drying conditions are not particularly limited and can be appropriately selected by those skilled in the art. According to a preferred embodiment of the present application, the 3D printed ceramic carrier after alkali treatment is washed with deionized water for 3-5 times and dried at 80-120℃.

[0067] In the present application, the 3D printed ceramic carrier provides a skeleton for the catalyst, the printed green body has a connected pore structure, and the 3D printed ceramic carrier is formed after debinding and sintering, and a slurry containing manganese oxide is coated on the surface of the 3D printed ceramic carrier to obtain a manganese-based catalyst, thereby improving the catalytic oxidation activity of the catalyst.

[0068] According to the present application, preferably, in step (3), the total coating amount of the slurry containing manganese oxide on the 3D-printed ceramic carrier is 40-160 g per liter, for example, 40 g, 50 g, 60 g, 70 g, 75 g, 80 g, 90 g, 100 g, 110 g, 120 g, 130 g, 140 g, 150 g, 160 g, and any range formed between any two values, preferably 50-130 g. This kind of implementation is more conducive to the active component manganese oxide to be fully exposed on the surface of the carrier, and improves the utilization efficiency of the active component. If the coating amount is too small, the content of the active component is insufficient, and the catalytic oxidation activity of the catalyst is poor; if the coating amount is too large, the adhesion of the coating is reduced, which is easy to fall off under the impact of the airflow, or to block the connecting channels of the carrier, causing uneven airflow distribution.

[0069] In the present application, the volume of the 3D-printed ceramic carrier is calculated according to the outer shape size of the carrier obtained by 3D printing. In the present application, the total coating amount of the slurry containing manganese oxide is calculated by the mass difference between the catalyst after calcination and the original 3D-printed ceramic carrier.

[0070] According to the present application, preferably, the slurry containing manganese oxide comprises manganese oxide powder and deionized water.

[0071] According to the present application, preferably, the average diameter of the manganese oxide powder in the slurry containing manganese oxide is less than 15 μm, preferably 7-13 μm.

[0072] In the present application, preferably, the slurry containing manganese oxide is obtained by uniformly mixing manganese oxide powder and deionized water, and the mixing method is not particularly limited as long as a uniformly mixed slurry containing manganese oxide is obtained. According to one preferred embodiment of the present application, the manganese oxide powder is added to deionized water, concentrated nitric acid is added to adjust the pH value of the system to less than 4, and the above mixture is ground sufficiently. The grinding conditions are not particularly limited, and the manganese oxide powder is uniformly mixed with deionized water, and the average diameter of the manganese oxide powder in the obtained slurry containing manganese oxide is less than 15 μm.

[0073] In the present application, the concentration and the amount of the concentrated nitric acid are not particularly limited, and the pH value of the system is less than 4.

[0074] In the present application, preferably, the grinding is achieved by ball milling, and the ball milling conditions include a ball milling time of 1-5 h and a rotation speed of 500-1500 rpm. The ball milling equipment is not particularly limited, and a vibration type ball mill is preferred.

[0075] According to the present application, preferably, the mass ratio of the manganese oxide powder to deionized water is 1:2.5-9, for example, 1:2.5, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, and any range formed between any two values, preferably 1:3-6.

[0076] According to the present application, preferably, the manganese oxide powder is selected from at least one of single manganese oxide, manganese-based spinel, manganese-based perovskite and manganese-based mullite.

[0077] According to the present application, preferably, the single manganese oxide is selected from at least one of α-MnO2, β-MnO2, γ-MnO2, δ-MnO2, λ-MnO2, ε-MnO2, α-Mn2O3 and Mn3O4.

[0078] According to the present application, preferably, the manganese-based spinel comprises A x Mn 3-x O4, A is selected from at least one of Mg, Ca, Fe, Co, Ni, Cu and Zn, and 0 < x < 3.

[0079] According to the present application, preferably, the manganese-based perovskite comprises BMnO3, B is selected from at least one of La, Sm, Sr and Ca.

[0080] According to the present application, preferably, the manganese-based mullite comprises CMn2O5, C is selected from at least one of Y, La and Sm.

[0081] In the present application, preferably, the manganese oxide powder is selected from at least one of α-MnO2, Cu x Mn 3-x O4 and Fe x Mn 3-x O4, wherein 0 < x < 3. In the present application, the source of the manganese oxide powder is not particularly limited, which can be commercially available or prepared by existing methods, as long as it can be used to prepare the slurry containing manganese oxide.

[0082] In the present application, preferably, it further comprises a process of drying and then sintering the 3D-printed ceramic carrier coated with the slurry containing manganese oxide, and the drying conditions are not particularly limited and can be adaptively adjusted by those skilled in the art as needed. Preferably, the temperature of the drying is 100-140℃.

[0083] According to the present application, preferably, in step (3), the sintering temperature is 300-650℃, preferably 400-450℃, and the sintering time is 1-5h, preferably 2-4h.

[0084] According to the present application, preferably, when the manganese oxide powder contains at least one of α-MnO2, β-MnO2, γ-MnO2, δ-MnO2, λ-MnO2, ε-MnO2 and manganese-based spinel, the sintering process comprises: heating to 300-450℃ at a rate of 3-6℃ / min, and maintaining for 2-4h.

[0085] According to the present application, preferably, when the manganese oxide powder does not contain at least one of α-MnO2, β-MnO2, γ-MnO2, δ-MnO2, λ-MnO2, ε-MnO2 and manganese-based spinel, the process of calcining comprises: heating at a rate of 3-6℃ / min to 350-650℃, and keeping for 2-4h.

[0086] In the present application, preferably, the different calcining temperatures are controlled to ensure that the manganese oxide does not change phase during the calcining process, for example, when the manganese oxide powder contains at least one of α-MnO2, β-MnO2, γ-MnO2, δ-MnO2, λ-MnO2, ε-MnO2 and manganese-based spinel, the calcining temperature is easy to change phase and sinter the active component if it exceeds 450℃. When the manganese oxide powder does not contain at least one of α-MnO2, β-MnO2, γ-MnO2, δ-MnO2, λ-MnO2, ε-MnO2 and manganese-based spinel, the manganese oxide can withstand calcining at 350-650℃ without changing phase.

[0087] The second aspect of the present application provides the manganese catalyst prepared by the method of the first aspect.

[0088] According to the present application, preferably, the manganese-based catalyst comprises a carrier and manganese oxide coated on the surface of the carrier. In the present application, the surface of the carrier includes the inner surface and the outer surface of the carrier.

[0089] According to the present application, preferably, the specific surface area of the carrier of the manganese-based catalyst is 6-20m 2 / g, preferably 8-15m 2 / g.

[0090] According to the present application, preferably, the specific surface area of the manganese oxide coated on the surface of the manganese-based catalyst is 10-80m 2 / g, preferably 20-60m 2 / g.

[0091] In the present application, preferably, the testing method of the specific surface area of the manganese oxide coated on the surface of the manganese-based catalyst is the same as the testing method of the specific surface area of the carrier, which is described in the foregoing specification and will not be repeated here.

[0092] The third aspect of the present application provides the use of the manganese-based catalyst of the second aspect in catalyzing oxidation reactions.

[0093] According to the present application, preferably, the manganese-based catalyst is used in the catalytic oxidation reaction of VOCs.

[0094] The VOCs are not particularly limited in the present application, and are conventional volatile organic compounds in the art, including at least one of alkanes (linear alkanes and cycloalkanes), alkenes, alkynes, benzene series, alcohols, aldehydes, ethers, ketones, acids, esters and halogenated hydrocarbons.

[0095] In the present application, the manganese-based catalyst is preferably used in the catalytic oxidation of alkanes, and more preferably used in the catalytic oxidation of propane. In the present application, the catalytic oxidation of propane using the manganese-based catalyst can maintain a high propane conversion rate at a high volume space velocity.

[0096] The catalytic oxidation reaction device is not particularly limited in the present application, and can be selected from conventional reaction devices in the art. According to a preferred embodiment of the present application, the catalytic oxidation reaction is carried out in a fixed bed reaction device.

[0097] The reaction conditions of the catalytic oxidation are not particularly limited in the present application, and can be adjusted by those skilled in the art according to the catalytic oxidation reaction. Preferably, the reaction conditions include: a reaction pressure of atmospheric pressure, a reaction temperature of 100-600℃, preferably 200-500℃, a volume space velocity of 1000-80000h -1 , preferably 10000-50000h -1 .

[0098] According to a particularly preferred embodiment of the present application, a method for preparing a manganese-based catalyst by 3D printing comprises the following steps:

[0099] (1) mixing a photosensitive resin mixture and a ceramic powder to obtain a photosensitive ceramic slurry, the mass ratio of the ceramic powder to the photosensitive resin mixture being 1:0.2-1.6, and carrying out 3D printing to obtain a printing blank;

[0100] (2) debinding and sintering the printing blank to obtain a 3D printed ceramic carrier;

[0101] The debinding process of the printing blank comprises: a first stage of heating at a rate of 3-7℃ / min to 460-530℃ and maintaining for 1-3h; and a second stage of heating at a rate of 8-12℃ / min to 680-720℃ and maintaining for 2-3h;

[0102] (3) coating a slurry containing manganese oxide on the surface of the 3D printed ceramic carrier, and calcining to obtain a manganese-based catalyst; step (3) further comprises alkali treatment of the 3D printed ceramic carrier before coating, and the alkali treatment process comprises: immersing the 3D printed ceramic carrier in an alkali solution at 30-80℃ for 1-6h; the manganese oxide powder is selected from α-MnO2, Cu x Mn 3-x O4 and Fex Mn 3-x at least one of O4, wherein 0 < x < 3;

[0103] The total coating amount of the manganese oxide-containing slurry on the 3D-printed ceramic carrier per liter is 50-130 g.

[0104] The present application will be described in detail below by way of examples and comparative examples. In the following examples and comparative examples, room temperature is 25°C;

[0105] The three-dimensional model is established by 3DMAX;

[0106] The 3D printing is completed by a sinking DLP-3D printer (model SU136A) of Foshan Guanglei Intelligent Manufacturing Co., Ltd.;

[0107] The planetary ball mill is a JC-QM series vertical planetary ball mill of JUCREATIVE ENVIRONMENTAL PROTECTION CO., LTD;

[0108] The vibration ball mill is a GZM-6 vibration ball mill of Tianjin Shengyuan Equipment Co., Ltd.;

[0109] The average particle size of the ceramic powder and the average diameter of the manganese oxide powder in the manganese oxide-containing slurry are the equivalent volume diameters obtained by the laser particle size method, and the test instrument is a Malvern Mastersizer 3000;

[0110] The fixed bed reaction device is a micro fixed bed reaction device designed and manufactured by Tianjin Pengxiang Technology Co., Ltd.;

[0111] The test method and test conditions of the specific surface area of the carrier of the manganese-based catalyst and the coated manganese oxide are described in the foregoing specification, and will not be described here.

[0112] Example 1

[0113] (1-1) Preparation of photosensitive resin mixture:

[0114] The epoxy acrylate prepolymer (Foshan Guanglei Intelligent Manufacturing Co., Ltd.) and 1,6-hexanediol diacrylate (HDDA) are mixed in a mass ratio of 1:1.5, and fully stirred to obtain a photosensitive resin. 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide and a powder dispersant (Yangzhou Lida Resin Co., Ltd., LD-1241) are added to the photosensitive resin, so that the photosensitive resin mixture contains 5 parts of a photoinitiator, 92 parts of a photosensitive resin, and 3 parts of a powder dispersant per 100 parts by weight of the photosensitive resin mixture. After fully stirring, a photosensitive resin mixture is obtained;

[0115] (1-2) Preparation of photosensitive ceramic slurry:

[0116] The photosensitive resin mixture obtained in (1-1) was placed in a high-speed disperser, and cordierite powder (Hebei Lingshou County Stone Mine Product Processing Plant, average particle size 4.5 μm) was weighed and slowly poured into the prepared photosensitive resin mixed solution. The mass ratio of ceramic powder to photosensitive resin mixture was 1:1. The high-speed disperser was turned on for stirring. When the ceramic powder was completely poured in, the stirring was continued for 40 min. The obtained preliminary mixed photosensitive ceramic slurry was repeatedly ground 4 times using a planetary ball mill, with each grinding time being 1 h and the rotation speed being 300 rpm, to obtain a photosensitive ceramic slurry;

[0117] (1-3) 3D printing:

[0118] The photosensitive ceramic slurry was placed in a barrel, and a three-dimensional model was introduced. After slicing, 3D printing was performed to obtain a printed body with a connected channel structure. The printed body had a vertical staggered structure composed of square columns with a side length of 1.2 mm, and had a cylindrical shape with a bottom diameter of 3 cm and a height of 1 cm. The 3D printing parameters were as follows: single layer solidification thickness 100 μm, single layer illumination time 10 s, and illumination intensity 5 mW / cm 2 . The printed body has a similar channel structure to Figure 1 .

[0119] (2) The printed body was subjected to debinding and sintering:

[0120] The debinding process of the printed body included: in the first stage, the temperature was increased to 500 ℃ at a rate of 5 ℃ / min and maintained for 2 h; in the second stage, the temperature was continued to increase to 700 ℃ at a rate of 10 ℃ / min and maintained for 2 h.

[0121] After the debinding treatment was completed, the temperature was continued to increase for sintering, at a rate of 10 ℃ / min to 1400 ℃, and maintained for 2 h; then the temperature was decreased to room temperature at a rate of 5 ℃ / min, to obtain a 3D printed ceramic carrier.

[0122] (3-1) Alkali treatment of the 3D printed ceramic carrier: the 3D printed ceramic carrier was placed in a 6% mass fraction KOH aqueous solution, with a carrier: alkali solution mass ratio of 1:9, and treated at a temperature of 50 ℃ for 6 h. The alkali-treated carrier was washed with deionized water for 3 times and dried at 110 ℃ for standby use.

[0123] (3-2) Preparation and coating of manganese oxide-containing slurry:

[0124] CuMn2O4 powder with spinel structure was synthesized by NaOH co-precipitation method, dried at 120 °C for 4 h, calcined at 450 °C for 3 h and cooled to room temperature for standby. CuMn2O4 powder was added to deionized water, the mass ratio of CuMn2O4 powder to deionized water was 1:4, 63% nitric acid was added to adjust the pH value of the system to less than 4, and a vibrating ball mill was used for grinding. The grinding conditions were: grinding time 2.5 h, rotation speed 1000 rpm. The average diameter of the manganese oxide powder in the slurry after ball milling was 10.3 μm. The slurry containing manganese oxide was uniformly coated on the surface of the 3D printed ceramic carrier.

[0125] (3-3) Post-treatment: the 3D printed ceramic carrier coated with the slurry containing manganese oxide of (3-2) was dried at 120 °C for 2 h, heated to 400 °C at a rate of 3 °C / min, and kept for 3 h to obtain a manganese-based catalyst, Figure 2 A physical photo of the manganese-based catalyst of Example 1.

[0126] Example 2

[0127] (1-1) Preparation of photosensitive resin mixture:

[0128] Polyurethane acrylate (Foshan Guangle Intelligent Manufacturing Co., Ltd.) and trimethylolpropane triacrylate (TMPTA) were mixed according to a mass ratio of 1:2, and fully stirred to obtain a photosensitive resin. Isopropyl thioxanthone (ITX) and powder dispersant (Yangzhou Lida Resin Co., Ltd., LD-1800) were added to the photosensitive resin mixture, so that the photosensitive resin mixture contained 8 parts of photoinitiator, 88 parts of photosensitive resin and 4 parts of powder dispersant per 100 parts of photosensitive resin mixture. After fully stirring, a photosensitive resin mixture was obtained;

[0129] (1-2) Preparation of photosensitive ceramic slurry:

[0130] The photosensitive resin mixture obtained in (1-1) was placed in a high-speed disperser. Bentonite powder (Hebei Lingshou Gushi Mineral Product Processing Factory, average particle size 3.6 μm) was weighed and slowly poured into the prepared photosensitive resin mixture. The mass ratio of ceramic powder to photosensitive resin mixture was 1:1.4. The high-speed disperser was turned on for stirring. When the ceramic powder was completely poured in, the stirring was continued for 60 min. The obtained preliminary mixed photosensitive ceramic slurry was repeatedly ground 3 times using a planetary ball mill, each time for 1.5 h at a rotation speed of 450 rpm, to obtain a photosensitive ceramic slurry.

[0131] (1-3) 3D printing:

[0132] Photosensitive ceramic slurry was placed in a material tank, a 3D model was imported, sliced, and then 3D printed to obtain a printed blank with a connected channel structure. The printed blank has a vertically interlaced structure composed of square prisms with a side length of 1.8 mm, and is cylindrical in shape with a base diameter of 3 cm and a height of 1 cm. The 3D printing parameters are as follows: single-layer curing thickness 125 μm, single-layer illumination time 15 s, and illumination intensity 8 mW / cm². 2 .

[0133] (2) Degreasing and sintering of the printed blank:

[0134] The degreasing process includes: a first stage where the temperature is increased to 530℃ at a rate of 7℃ / min and held for 2 hours; a second stage where the temperature is increased to 720℃ at a rate of 12℃ / min and held for 2.5 hours. After degreasing, sintering is carried out by further heating at a rate of 10℃ / min to 1500℃ and held for 1.5 hours; then the temperature is cooled to room temperature at a rate of 5℃ / min to obtain the 3D printed ceramic carrier.

[0135] (3-1) Alkali treatment of 3D printing ceramic carrier: The 3D printing ceramic carrier was placed in an 18% NaOH aqueous solution (carrier:alkali solution mass ratio 1:5) and treated at 40℃ for 1 hour. After alkali treatment, the carrier was rinsed three times with deionized water and dried at 100℃ for later use.

[0136] (3-2) Preparation and coating of slurry containing manganese oxides:

[0137] Synthesis of manganese-based spinel Co using sodium oxalate coprecipitation method 1.5 Mn 1.5 O4 powder was dried at 120℃ for 4 hours, calcined at 450℃ for 3 hours, and then cooled to room temperature for later use. Co... 1.5 Mn 1.5 O4 powder is added to deionized water, Co 1.5 Mn 1.5 The mass ratio of O4 powder to deionized water was 1:3. 63% concentrated nitric acid was added to adjust the pH of the system to less than 4. The mixture was then thoroughly ground using a vibratory ball mill under the following conditions: milling time 2 hours, speed 1100 rpm. The average diameter of the manganese oxide powder in the slurry after milling was 12 μm. The manganese oxide-containing slurry was then uniformly coated onto the surface of a 3D-printed ceramic substrate.

[0138] (3-3) Post-treatment: The 3D printed ceramic carrier coated with the manganese oxide slurry in (3-2) was dried at 120℃ for 2h, and then heated to 450℃ at a rate of 3℃ / min and held for 3h to obtain the manganese-based catalyst.

[0139] Example 3

[0140] (1-1) Preparation of photosensitive resin mixture solution:

[0141] Polyurethane acrylate (Foshan Guangle Intelligent Manufacturing Co., Ltd.) and tripropylene glycol diacrylate (TPGDA) were mixed at a mass ratio of 1:0.8, and fully stirred to obtain a photosensitive resin. Phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide (photoinitiator 819) and powder dispersant (Yangzhou Lida Resin Co., Ltd., LD-1800) were added to the photosensitive resin mixture solution, so that the photosensitive resin mixture solution contained 3 parts of photoinitiator, 92 parts of photosensitive resin, and 5 parts of powder dispersant per 100 parts of photosensitive resin mixture solution. After fully stirring, a photosensitive resin mixture solution was obtained.

[0142] (1-2) Preparation of photosensitive ceramic slurry:

[0143] The photosensitive resin mixture solution obtained in (1-1) was placed in a high-speed disperser, and kaolin powder (Hebei Lingshou County Gushi Mine Product Processing Factory, average particle size 2.8 μm) was weighed and slowly poured into the prepared photosensitive resin mixture solution. The mass ratio of ceramic powder to photosensitive resin mixture solution was 1:0.5. The high-speed disperser was turned on and stirred at a speed of 400 rpm. After the ceramic powder was completely poured in, the stirring was continued for 25 min. The obtained preliminary mixed photosensitive ceramic slurry was repeatedly ground 5 times using a planetary ball mill, with each grinding time being 0.8 h and the rotation speed being 450 rpm, to obtain a photosensitive ceramic slurry.

[0144] (1-3) 3D printing:

[0145] The photosensitive ceramic slurry was placed in a hopper, and a three-dimensional model was introduced. After slicing, 3D printing was performed to obtain a printed body with a connected channel structure. The printed body had a vertical staggered structure composed of square columns with a side length of 0.8 mm, and had a cylindrical shape with a bottom diameter of 3 cm and a height of 1 cm. The 3D printing parameters were as follows: single layer solidification thickness 40 μm, single layer light exposure time 15 s, light exposure intensity 3 mW / cm 2 .

[0146] (2) Degreasing and sintering of the printed body:

[0147] The degreasing process included: in the first stage, the temperature was raised to 460°C at a rate of 3°C / min and maintained for 2 h; in the second stage, the temperature was continued to rise to 680°C at a rate of 8°C / min and maintained for 3 h. After the degreasing treatment was completed, the sintering was continued by raising the temperature to 1350°C at a rate of 10°C / min and maintaining for 2 h; then the temperature was lowered to room temperature at a rate of 5°C / min;

[0148] (3-1) Alkali treatment of 3D-printed ceramic support: The 3D-printed ceramic support was placed in a 10% KOH aqueous solution, with a support:alkali solution mass ratio of 1:6, and treated at 80°C for 2 h. The alkali-treated support was rinsed with deionized water three times and dried at 90°C for use.

[0149] (3-2) Preparation and coating of slurry containing manganese oxide:

[0150] Single manganese oxide a-Mn02 powder was synthesized by a hydrothermal method, dried at 120°C for 4 h, and calcined at 450°C for 3 h and then cooled to room temperature for use. The a-Mn02 powder was added to deionized water, with a mass ratio of a-Mn02 powder to deionized water of 1:6, and 63% nitric acid was then added to adjust the pH value to less than 4. A vibrating ball mill was used for grinding, with a grinding time of 3 h and a rotation speed of 800 rpm. The average diameter of the manganese oxide powder in the slurry after grinding was 8 μm. The slurry containing manganese oxide was uniformly coated on the surface of the 3D-printed ceramic support.

[0151] (3-3) Post-treatment: The 3D-printed ceramic support coated with the slurry containing manganese oxide in (3-2) was dried at 120°C for 2 h, and then heated to 450°C at a rate of 3°C / min and maintained for 3 h to obtain a manganese-based catalyst.

[0152] Example 4

[0153] The catalyst was prepared according to the method of Example 1, except that the slurry containing manganese oxide was coated without alkali treatment in step (3), and the other conditions were the same as in Example 1.

[0154] Example 5

[0155] The catalyst was prepared according to the method of Example 1, except that the debinding in step (2) was performed at a rate of 15°C / min to 850°C and maintained for 5 h.

[0156] Example 6

[0157] The catalyst was prepared according to the method of Example 1, except that the amount of manganese oxide powder added was changed so that the total coating amount of the catalyst on the ceramic support was 30 g / L per liter of ceramic support.

[0158] Comparative Example 1

[0159] (1) A custom commercial cordierite support (Jiangxi Guocui Environmental Technology Co., Ltd., ceramic honeycomb support) was used, with a bulk density of 0.5 kg / L, a pore volume of 0.5 mL / g, and single cubic column straight channels inside; it was cut into a cylinder with the same size as that of Example 1 as the support (bottom diameter 3 cm, height 1 cm);

[0160] (2) The cordierite carrier obtained in step (1) was subjected to alkali treatment, coating of a slurry containing manganese oxide, and post-treatment, under the same conditions as in Example 1.

[0161] Comparative Example 2

[0162] (1) A commercial cordierite carrier (Jiangxi Guocui Environmental Protection Technology Co., Ltd., ceramic honeycomb carrier) was used, with a bulk density of 0.5 kg / L, a pore volume of 0.5 mL / g, and a single cubic column straight channel inside; it was cut into a cylinder with the same size as in Example 1 (bottom diameter 3 cm, height 1 cm) as the carrier;

[0163] (2) The cordierite carrier obtained in step (1) was subjected to alkali treatment, and a slurry containing Pt and Al2O3 active component was coated on the surface of the carrier after alkali treatment. A certain amount of Al2O3 and H2PtCl6 was added to deionized water, and a vibration ball mill (Tianjin Shengyuan Equipment Co., Ltd., GZM-6) was used to grind the mixture. The specific grinding conditions were as follows: grinding time 2.5 h, rotation speed 1000 rpm, and the average particle diameter in the mixture after grinding was 10 μm. The mixture after grinding was stirred for 1 h to prepare the active component slurry, and the solid content of the slurry was controlled at 15 wt%. Then the active component slurry was uniformly coated on the surface of the carrier, so that the total coating amount of the coating layer was 60 g / L, of which the coating amount of Pt was 0.25 g / L, and the rest was Al2O3 active component. After coating, drying and calcination were performed, and the drying and calcination conditions were the same as in Example 1.

[0164] Comparative Example 3

[0165] The catalyst was prepared according to the method of Example 1, except that no manganese oxide coating was coated, and step (3-2) was not performed.

[0166] Comparative Example 4

[0167] The catalyst was prepared according to the method of Example 1, except that in step (3), a slurry containing Pt and Al2O3 active component was coated on the carrier. A certain amount of Al2O3 and H2PtCl6 was added to deionized water, and a vibration ball mill (Tianjin Shengyuan Equipment Co., Ltd., GZM-6) was used to grind the mixture. The specific grinding conditions were as follows: grinding time 2.5 h, rotation speed 1000 rpm, and the average particle diameter in the mixture after grinding was 10 μm. The mixture after grinding was stirred for 1 h to prepare the active component slurry, and the solid content of the slurry was controlled at 15 wt%. Then the active component slurry was uniformly coated on the surface of the carrier, so that the total coating amount of the coating layer was 60 g / L, of which the coating amount of Pt was 0.25 g / L, and the rest was Al2O3 active component. After coating, drying and calcination were performed, and the drying and calcination conditions were the same as in Example 1.

[0168] Test Example 1

[0169] The results of the specific surface area of the support of the manganese-based catalysts prepared in the examples and comparative examples and the specific surface area of the coated manganese oxides are shown in Table 1.

[0170] Table 1

[0171]

[0172] From the results in Table 1, it can be seen that the catalyst support of the examples of the present application subjected to alkali treatment has a larger specific surface area than the conventional cordierite honeycomb support, which is beneficial to the full dispersion of the manganese oxide active component and to the catalytic oxidation reaction of VOCs.

[0173] Example 4 The catalyst was prepared according to the method of Example 1, and step (3) was not subjected to alkali treatment. The specific surface area of the support was smaller than that of Example 1, and the loading of the active component was also smaller than that of Example 1.

[0174] Test Example 2

[0175] The catalytic activity of the catalysts of the examples and comparative examples was evaluated in terms of the activity in the catalytic oxidation reaction of propane. The reaction was completed on a micro fixed bed reaction device designed and manufactured by Tianjin Pengxiang Science and Technology Company, which was equipped with a Multigas 2030 type infrared detector of MKS Company.

[0176] The catalytic oxidation reaction conditions were as follows: the reaction was carried out at normal pressure, the initial temperature was 250°C, the temperature was increased to 480°C at a rate of 5°C / min, the gas volume composition was 600 ppmv propane + 21% O2+ 79% N2, and the volume space velocity was 26000 h -1 -1 at 400°C. The propane conversion is shown in Table 2.

[0177] Propane conversion = 1 - (residual propane content / propane raw material content) x 100%.

[0178] Table 2

[0179] Numbering Propane conversion (%) Example 1 87.6 Example 2 78.1 Example 3 84.4 Example 4 79.3 Example 5 82.3 Example 6 77.6 Comparative Example 1 66.5 Comparative Example 2 39.7 Comparative Example 3 1.2 Comparative Example 4 49.7

[0180] From the results in Table 2, it can be seen that the catalysts prepared according to the method of Examples 1-6 of the present application have higher propane oxidation activity in the catalytic oxidation reaction of propane, and the propane conversion can all reach more than 77%. Figure 3 The relationship between the catalytic oxidation of propane conversion and temperature of Examples 1-6 and Comparative Examples 1-4 is shown in the graph from Figure 3 It can be seen from the graph that the propane conversion of the catalyst prepared in the examples is higher than that of the catalyst prepared in the comparative examples at the same reaction temperature. Example 4 was not subjected to alkali treatment, the specific surface area of the support was too small, the loading of the active component was small, and the propane conversion was lower under the same conditions.

[0181] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application and fall within the protection scope of the present application.

Claims

1. A method for the preparation of a manganese-based catalyst by 3D printing, characterized in that, The method comprises the following steps: (1) mixing a photosensitive resin mixture and a ceramic powder to obtain a photosensitive ceramic slurry, and performing 3D printing to obtain a printing blank; (2) performing debinding and sintering on the printing blank to obtain a 3D printed ceramic carrier; (3) coating a slurry containing manganese oxide on the surface of the 3D printed ceramic carrier, and baking to obtain a manganese-based catalyst; The photosensitive resin mixture comprises, based on 100 parts of the photosensitive resin mixture, 0.5-10 parts of a photoinitiator, 85-95 parts of a photosensitive resin, and 2-10 parts of a powder dispersant. The photosensitive resin is a mixture of an acrylate-based prepolymer and an acrylate monomer, and the acrylate-based prepolymer is an epoxy acrylate-based prepolymer and / or a polyurethane acrylate-based prepolymer. The printing blank has a vertical staggered structure composed of cubic columns with a bottom side length of 0.5-2 mm.

2. The method of claim 1, wherein, The photosensitive resin mixture comprises, based on 100 parts of the photosensitive resin mixture, 3-8 parts of a photoinitiator, 88-92 parts of a photosensitive resin, and 3-5 parts of a powder dispersant.

3. The method of claim 2, wherein, The photoinitiator is at least one selected from 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide, and isopropyl thioxanthone.

4. The method of claim 1, wherein, The mass ratio of the acrylate-based prepolymer to the acrylate monomer in the photosensitive resin is 1:0.6-2.

2.

5. The method of claim 4, wherein, The mass ratio of the acrylate-based prepolymer to the acrylate monomer in the photosensitive resin is 1:0.8-2.

6. The method of any of claims 1-5, wherein, In step (1), the mass ratio of the ceramic powder to the photosensitive resin mixture is 1:0.1-2.

7. The method of claim 6, wherein, In step (1), the mass ratio of the ceramic powder to the photosensitive resin mixture is 1:0.2-1.

6.

8. The method of any one of claims 1-5, wherein, The ceramic powder is a silico-aluminate natural mineral clay. The average particle size of the ceramic powder is less than 10 μm.

9. The method of claim 8, wherein, The ceramic powder is at least one selected from cordierite, kaolin, and bentonite. The average particle size of the ceramic powder is 2.5-5 μm.

10. The method of any one of claims 1-5, wherein, The conditions of the 3D printing include: single layer solidification thickness 20-150 μm, single layer light exposure time 5-20 s, light exposure intensity 2-10 mW / cm 2 .

11. The method of any one of claims 1-5, wherein, In step (2), the debinding process of the printing blank comprises: heating at a temperature of 400-800 ℃ for 1-10 h.

12. The method of claim 11, wherein, The debinding of the printing blank is divided into two stages: the first stage is to heat at a rate of 3-8 ℃ / min to 450-550 ℃, and to keep for 0.5-4 h; The second stage is to continue heating at a rate of 8-15 ℃ / min to 650-750 ℃, and to keep for 1-3 h.

13. The method of claim 12, wherein, The debinding of the printing blank is divided into two stages: the first stage is to heat at a rate of 3-7 ℃ / min to 460-530 ℃, and to keep for 1-3 h; The second stage is to heat at a rate of 8-12 ℃ / min to 680-720 ℃, and to keep for 2-3 h.

14. The method of claim 1, wherein, The sintering conditions comprise: a sintering temperature of 1300-1600 ℃; a sintering time of 1-3 h; and a heating rate of 8-15 ℃ / min.

15. The method of claim 14, wherein, The sintering conditions comprise: a sintering temperature of 1350-1500 ℃; a sintering time of 1.5-2.5 h; and a heating rate of 9-12 ℃ / min.

16. The method of claim 1, wherein, After sintering, the cooling rate is 3-8 ℃ / min.

17. The method of claim 16, wherein, After sintering, the cooling rate is 4-6 ℃ / min.

18. The method of any one of claims 1-5, wherein, In step (3), the 3D-printed ceramic carrier before coating is subjected to alkali treatment, and the alkali treatment process comprises: immersing the 3D-printed ceramic carrier in an alkali solution at 30-80℃ for 0.5-10h. And / or, the alkali solution is an aqueous solution of NaOH and / or KOH, and the mass fraction of NaOH and / or KOH is 4%-20%.

19. The method of claim 18, wherein, In step (3), the 3D-printed ceramic carrier before coating is subjected to alkali treatment, and the alkali treatment process comprises: immersing the 3D-printed ceramic carrier in an alkali solution at 30-80℃ for 1-6h. And / or, the alkali solution is an aqueous solution of NaOH and / or KOH, and the mass fraction of NaOH and / or KOH is 6-18%.

20. The method of claim 18, wherein, The mass ratio of the 3D-printed ceramic carrier to the alkali solution is 1:4-10. and / or the specific surface area of the 3D-printed ceramic support after the alkaline treatment is 6-20 m 2 / g.

21. The method of claim 20, wherein, The mass ratio of the 3D-printed ceramic carrier to the alkali solution is 1:5-9. and / or the specific surface area of the 3D-printed ceramic support after the alkaline treatment is 8-15 m 2 / g.

22. The method of any one of claims 1-5, wherein, In step (3), the total coating amount of the slurry containing manganese oxide on the 3D-printed ceramic carrier per liter is 40-160g.

23. The method of claim 22, wherein, In step (3), the total coating amount of the slurry containing manganese oxide on the 3D-printed ceramic carrier per liter is 50-130g.

24. The method of claim 1, wherein, The slurry containing manganese oxide comprises manganese oxide powder and deionized water.

25. The method of claim 24, wherein, The mass ratio of the manganese oxide powder to deionized water is 1:2.5-9. And / or, the manganese oxide powder is selected from at least one of single manganese oxide, manganese-based spinel, manganese-based perovskite and manganese-based mullite; And / or, the average diameter of the manganese oxide powder in the slurry containing manganese oxide is less than 15μm.

26. The method of claim 25, wherein, The mass ratio of the manganese oxide powder to deionized water is 1:3-6. And / or, the average diameter of the manganese oxide powder in the slurry containing manganese oxide is 7-13μm.

27. The method of claim 25, wherein, The single manganese oxide is selected from at least one of α-MnO2, β-MnO2, γ-MnO2, δ-MnO2, λ-MnO2, ε-MnO2, α-Mn2O3 and Mn3O4; and / or, the manganese-based spinel comprises A x Mn 3-x O4, A is selected from at least one of Mg, Ca, Fe, Co, Ni, Cu, and Zn, and 0 < x < 3. And / or, the manganese-based perovskite comprises BMnO3, and B is selected from at least one of La, Sm, Sr and Ca; And / or, the manganese-based mullite comprises CMn2O5, and C is selected from at least one of Y, La and Sm.

28. The method of any one of claims 1-5, wherein, In step (3), the calcination temperature is 300-650℃, and the calcination time is 1-5h.

29. The method of claim 28, wherein, In step (3), the calcination temperature is 400-450℃, and the calcination time is 2-4h.

30. The method of claim 28, wherein, When the manganese oxide powder contains at least one of α-MnO2, β-MnO2, γ-MnO2, δ-MnO2, λ-MnO2, ε-MnO2 and manganese-based spinel, the calcination process comprises: heating at a rate of 3-6℃ / min to 300-450℃ and maintaining for 2-4h.

31. The method of claim 28, wherein, When the manganese oxide powder does not contain at least one of α-MnO2, β-MnO2, γ-MnO2, δ-MnO2, λ-MnO2, ε-MnO2 and manganese-based spinel, the calcination process comprises: heating at a rate of 3-6℃ / min to 350-650℃ and maintaining for 2-4h.

32. The manganese-based catalyst produced by the process of any one of claims 1 to 31.

33. The manganese-based catalyst of claim 32, wherein, The manganese-based catalyst comprises a support and a manganese oxide coated on the surface of the support.

34. The manganese-based catalyst of claim 33, wherein, The specific surface area of the support of the manganese-based catalyst is between 6 and 20 m 2 / g; and / or the manganese-based catalyst has a specific surface area of the surface-coated manganese oxide of 10-80 m 2 / g.

35. The manganese-based catalyst of claim 34, wherein, The specific surface area of the support of the manganese-based catalyst is between 8 and 15 m 2 / g; and / or the manganese-based catalyst has a specific surface area of the surface-coated manganese oxide of 20-60 m 2 / g.

36. Use of the manganese-based catalyst of any one of claims 32 to 35 in catalyzing an oxidation reaction.

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