Process for the preparation of manganese-based catalysts, catalysts prepared and use thereof

Abstract

The application relates to the field of catalytic materials, and discloses a preparation method of a manganese-based catalyst, a prepared catalyst and application, the method comprises the following steps: carrying out a hydrothermal reaction on a regular carrier in a manganese-based precursor dispersion liquid, and carrying out calcination to obtain a manganese-based catalyst; wherein the manganese-based precursor dispersion liquid comprises a manganese salt, an optional M metal soluble salt and a solvent, and a precipitation aid is optionally added; the M metal element is selected from at least one of Fe, Co, Ni, Cu and Ce. The method loads a manganese-based active component on a regular carrier with connected channels through an in-situ growth method, the operation is simple, the active component loading amount is flexibly controllable, and the catalytic oxidation activity of the prepared catalyst can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalytic materials, in particular to a preparation method of a manganese-based catalyst, and the catalyst prepared by the method and application thereof. BACKGROUND

[0002] 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℃. NO x and VOCs are important precursors of atmospheric PM 2.5 and near-surface O3. With the gradual emergence of the effect of NO x emission reduction, the sensitivity of O3 pollution control to VOCs management has increased significantly, and VOCs have become the key to solving the problem of regional atmospheric complex pollution. Industrial source VOCs emission control is still the focus of current work, and the commonly used technologies include recovery technologies represented by adsorption and absorption, and destruction technologies represented by catalytic oxidation and regenerative combustion. Among them, the catalytic oxidation method has broad application prospects due to its high treatment efficiency, small secondary pollution, and strong equipment compatibility. The catalysts that have been commercialized are mostly honeycomb monolithic catalysts with cordierite and honeycomb ceramic as the carrier, which are coated with Al2O3, rare earth modified oxides, and coupled with Pd, Pt, and other noble metal active components.

[0003] Although the traditional honeycomb monolithic catalysts have stable VOCs oxidation performance and industrial operation effect, the catalyst utilization efficiency is not high, which indirectly increases the cost of using the catalyst. In the process of coating the catalyst active component, in order to improve the coating amount, it is necessary to prepare a catalyst slurry with suitable physical and chemical properties, and then go through repeated coating, drying, and other processes to produce the target monolithic catalyst. On the other hand, the high cost of commercial noble metal catalysts has always limited their further use in the industry, and the development of high-performance, low-cost alternative materials has become an urgent need.

[0004] 3D printing technology is a new type of intelligent manufacturing technology that uses computer control to stack materials to form a three-dimensional target structure. Hajimirzaee et al. confirmed by computational fluid dynamics analysis that the 3D printed carrier significantly improves the degree of air flow turbulence, and the turbulence / mass transfer and surface area are significantly increased (Fuel, 2020, 274:117848), which shows that the characteristics of the 3D printed carrier have outstanding application potential in catalysts. However, how to combine the 3D printed carrier with the active component to improve the application of the 3D printed carrier in the field of VOCs catalytic oxidation still needs to be overcome. SUMMARY

[0005] The application aims to overcome the problems of limited loading amount of active components and limited contact between active components and catalytic oxidants in the prior art, and provides a preparation method of a manganese-based catalyst, the prepared catalyst and application.

[0006] To achieve the above-mentioned purpose, the first aspect of the application provides a preparation method of a manganese-based catalyst, comprising the following steps: performing a hydrothermal reaction on a regular carrier in a manganese-based precursor dispersion liquid, and calcining to obtain a manganese-based catalyst.

[0007] The manganese-based precursor dispersion liquid comprises a manganese salt, an optional M metal soluble salt and a solvent, and an optional precipitant.

[0008] The second aspect of the application provides a manganese-based catalyst, wherein the catalyst comprises a regular carrier and an active component layer loaded on the surface of the regular carrier, and the active component layer comprises a manganese compound and an optional M metal.

[0009] Preferably, the M metal element is at least one selected from Fe, Co, Ni, Cu and Ce.

[0010] The third aspect of the application provides a preparation method of a manganese-based catalyst prepared by 3D printing, comprising the following steps:

[0011] (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;

[0012] (2) performing debinding and sintering on the printing blank to obtain a 3D printed ceramic carrier;

[0013] (3) performing a hydrothermal reaction on the 3D printed ceramic carrier in a manganese-based precursor dispersion liquid, and calcining to obtain a manganese-based catalyst.

[0014] Preferably, the hydrothermal reaction is performed under the following conditions: the reaction temperature is 90-160℃, preferably 110-140℃; and the reaction time is 12-24h, preferably 12-18h.

[0015] Preferably, in step (3), a precipitant is further added in the hydrothermal reaction, and the ratio of the total molar amount of Mn and M metal to the molar amount of the precipitant is 1:1-2.5, preferably 1:1.4-2.

[0016] The fourth aspect of the present application provides the manganese-based catalyst prepared by the method of the third aspect;

[0017] Preferably, the manganese-based catalyst comprises a 3D-printed ceramic carrier and a manganese-based active component grown in situ on the 3D-printed ceramic carrier.

[0018] The fifth aspect of the present application provides an application of the manganese-based catalyst of the second aspect or the fourth aspect in catalyzing an oxidation reaction.

[0019] The preparation method provided by the present application has the following beneficial effects:

[0020] (1) In the present application, the manganese-based active component is loaded on the surface of the regular carrier by the in-situ growth method, realizing one-time loading of the active component layer, flexibly controlling the loading amount of the active component, and obtaining a higher amount of manganese-containing loading layer in a single loading, which simplifies the loading procedure of the active component of the catalyst and can be used to prepare a catalyst with a high loading amount of active component.

[0021] (2) In the present application, preferably, the carrier prepared by 3D printing has three-dimensionally connected pores and vertically staggered cross-pore structures. The connected pores of the carrier can fully expose the surface manganese-based active component. Under the same loading amount, the obtained catalyst can have higher catalytic oxidation activity, can effectively alleviate the problems of uneven gas flow distribution and insufficient residence time of flue gas in the pores of the catalyst, can improve the reaction contact conditions, can improve the atomic utilization efficiency of the active component, and can further improve the VOCs catalytic oxidation activity of the prepared catalyst.

[0022] (3) In the present application, preferably, the manganese-based active component is used to replace the noble metal active component loaded on the surface of the carrier, effectively reducing the cost of the catalyst, and can be popularized to the active component loading process on the surface of the carrier of the fixed bed catalytic system, and has a broad application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a schematic diagram of the 3D printing model structure in Example 1.

[0024] Figure 2 It is a physical photo of the manganese-based catalyst prepared in Example 1. DETAILED DESCRIPTION

[0025] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are understood to be approximate values. The exact numerical values of the endpoints of the ranges and the separate points are not to be construed as being strictly limited to the exact numerical values recited. Rather, each range of numerical values should be considered as having been reported with a degree of error consistent with the precision of the numerical values being described. The ranges and individual points are understood to encompass all values falling within the range, including the endpoints of the ranges and the individual points.

[0026] The first aspect of the present application provides a preparation method of a manganese-based catalyst, comprising the following steps: subjecting a regular carrier to a hydrothermal reaction in a manganese-based precursor dispersion, and calcining to obtain a manganese-based catalyst.

[0027] In the present application, the manganese-based precursor dispersion comprises a manganese salt, optionally a soluble salt of M metal, and a solvent, and optionally a precipitation aid is added; the M metal element is selected from at least one of Fe, Co, Ni, Cu and Ce.

[0028] In the present application, the regular carrier has the conventional interpretation in the art, which refers to a carrier with a determinable overall size and a regular external and internal structure, and has high mechanical stability and specific surface area. The material of the regular carrier is not particularly limited, and a material suitable for preparing a catalyst can be selected by a person skilled in the art as the regular carrier, and the ceramic-based regular carrier is preferred. In the present application, the source of the regular carrier is not particularly limited, and the regular carrier can be obtained by commercial purchase or prepared by an existing method, as long as the properties of the regular carrier meet the preparation conditions of the manganese-based catalyst.

[0029] In the present application, the "optional" means containing or not containing, adding or not adding, and using or not using, unless otherwise specified. Specifically, the "optional soluble salt of M metal" in the present application means that the soluble salt of M metal can be added or not added.

[0030] According to the present application, preferably, the conditions of the hydrothermal reaction include that the reaction temperature is 90-160℃, preferably 110-140℃; and the reaction time is 12-24h, preferably 12-18h.

[0031] According to the present application, preferably, the volume ratio of the regular carrier to the manganese-based precursor dispersion is 1:8-20, preferably 1:9-15.

[0032] In the present application, the composition and content of the manganese-based precursor dispersion and the addition amount of the precipitation aid are described below, and will not be repeated here.

[0033] According to the present application, preferably, the precipitation aid is selected from at least one of easily hydrolyzed organic amines, soluble carbonates and soluble bicarbonates, and is preferably selected from at least one of urea, NH4HCO3 and (NH4)2CO3.

[0034] The second aspect of the present application provides a manganese-based catalyst, wherein the catalyst comprises a regular carrier and an active component layer loaded on the surface of the regular carrier, and the active component layer comprises a manganese compound and optionally an M metal.

[0035] According to the application, preferably, the M metal element is selected from at least one of Fe, Co, Ni, Cu and Ce.

[0036] According to the application, preferably, the content of the active component layer on the surface of the shaped carrier is 30-150 g / L, preferably 50-140 g / L, based on 1 L of the volume of the shaped carrier.

[0037] According to the application, preferably, the molar ratio of Mn to M metal in the active component layer is 1:0-1, preferably 1:0.02-0.3.

[0038] In the application, the prepared manganese-based catalyst has a high active component layer loading on the surface of the shaped carrier, and the active component loading can be flexibly controlled, and the manganese-based catalyst has high catalytic oxidation activity.

[0039] In the application, the content of the manganese-based active component layer is calculated by the mass difference between the catalyst after calcination and the original carrier.

[0040] The third aspect of the application provides a method for preparing a manganese-based catalyst by 3D printing, wherein the method comprises the following steps:

[0041] (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;

[0042] (2) performing debinding and sintering on the printing blank to obtain a 3D printed ceramic carrier;

[0043] (3) performing hydrothermal reaction on the 3D printed ceramic carrier in a manganese-based precursor dispersion liquid, and calcining to obtain a manganese-based catalyst.

[0044] In the application, the manganese-based active component is loaded on the surface of the 3D printed ceramic carrier in an in-situ growth manner, the manganese-based active component has strong oxidation-reduction properties, is loaded on the carrier, and through the interaction in the calcination process, the catalytic activity and mechanical strength of the catalyst are improved. The method can realize single flexible control of the manganese-based active component loading, and the manganese-based catalyst obtained after calcination treatment can replace the noble metal catalyst and has good catalytic oxidation activity. The connected pores of the carrier can effectively alleviate the problems of uneven gas flow distribution and insufficient residence time of flue gas in the pores of the catalyst.

[0045] In the application, preferably, the carrier prepared by 3D printing has three-dimensional connected pores and vertically staggered cross-pore structures. Compared with the one-dimensional array honeycomb pore structure of the traditional ceramic carrier, the connected pores of the carrier can fully expose the surface manganese-based active component, improve the reaction contact conditions, and improve the atomic utilization efficiency of the active component.

[0046] According to the present application, preferably, the photosensitive resin mixture comprises 1-12 parts of the photoinitiator, 82-92 parts of the photosensitive resin, and 3-7 parts of the powder dispersant, preferably 3-8 parts of the photoinitiator, 88-92 parts of the photosensitive resin, and 3-5 parts of the powder dispersant, based on 100 parts of the mass of the photosensitive resin mixture.

[0047] In the present application, the photosensitive resin mixture is obtained by uniformly mixing the photoinitiator, the photosensitive resin, and the powder dispersant, and the mixing method is not particularly limited, and can be adjusted by those skilled in the art as needed, as long as a uniformly mixed photosensitive resin mixture is obtained.

[0048] 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-diphenylphosphine oxide (photoinitiator TPO), phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator 819), and isopropyl thioxanthone (ITX).

[0049] According to the present application, the specific composition of the photosensitive resin can be selected in a wide range, and can be selected according to conventional technical means in the art. Preferably, 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.

[0050] In the present application, the acrylate monomer can be a conventional acrylate monomer in the art, and is preferably at least one selected from 1,6-hexanediol diacrylate (HDDA), tripropyleneglycol diacrylate (TPGDA), and trimethylolpropane triacrylate (TMPTA).

[0051] In the present application, the powder dispersant is a commonly used commercial dispersant, and is preferably at least one selected from sulfated salt-based powder dispersants, polyol-based powder dispersants, polyurethane-based powder dispersants, and silane coupling agent-based powder dispersants.

[0052] According to the present application, preferably, the mass ratio of the acrylate-based prepolymer to the acrylate monomer in the photosensitive resin is 1:0.5-2.3, such as 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.2, 1:1.4, 1:1.5, 1:1.6, 1:1.8, 1:2, 1:2.2, 1:2.3, and any range between any two values, and preferably 1:0.8-1.5.

[0053] According to the present application, preferably, in step (1), the mass ratio of the ceramic powder and the photosensitive resin mixture is 1:0.2-1.5, for example, 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, 1:1.5, and any range between any two values, preferably 1:0.5-1.4. The photosensitive ceramic slurry obtained by mixing according to the above mass ratio has a fast curing speed during subsequent 3D printing, and the structure stability of the carrier material obtained after sintering is better.

[0054] 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. During the process, the high-speed disperser is turned on for stirring, 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. The photosensitive ceramic slurry is obtained by grinding.

[0055] 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.

[0056] 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.

[0057] 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, fast curing speed during 3D printing, and high production efficiency. If the ceramic powder has a larger particle size, the uniformity thereof can be further improved by subsequent ball milling.

[0058] In the present application, the printing blank is prepared by 3D printing, and a three-dimensional structure design is performed using modeling software. The photosensitive ceramic slurry is placed in the cylinder of the 3D printer, and the three-dimensional model is imported. After being sliced by a computer, 3D printing is performed to obtain a printing blank with a connected channel structure.

[0059] In the present application, preferably, the three-dimensional structure design is performed using modeling software, and the modeling software is selected from SolidWorks, 3DMAX, AutoCAD, or Materialise Magics.

[0060] According to the present application, preferably, 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 .

[0061] In the present application, the "printed blank" is a general term for the blanks prepared, which can be personalized to customize complex three-dimensional structures suitable for different scenarios by printing, without relying on molds and without the need for complex post-processing of the carrier. Compared with traditional material processing technology, it has the characteristics of high raw material utilization, strong structure design, high structure adjustment flexibility, etc. It is an ideal method for designing three-dimensional cross-linked channel carrier materials.

[0062] In the present application, the size and structure of the printed blank are not particularly limited, and those skilled in the art can appropriately select them according to the application scenario 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.

[0063] The present application does not have a special limitation on the interconnected channel structure, which has the conventional interpretation in the art. In the present application, the interconnected channel structure refers to the intersection and communication between the vertical and horizontal channels of the printed blank, which has good permeability, and the distribution of the channels is not particularly limited, and those skilled in the art can adaptively select it 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 .

[0064] According to the present application, preferably, the printed blank has a vertical staggered structure composed of cubic columns with a bottom edge length of 0.5-2 mm. The printed blank with the above structure, after being processed, is used 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.

[0065] In the present application, the vertical staggered structure has the conventional interpretation in the art, which refers to the structure perpendicular to each other formed by the overlapping of the cubic columns, as shown in Figure 1 . The cubic column refers to a column with two equal square bottom surfaces and a side surface perpendicular to the bottom surface, and the bottom edge length refers to the length of the side of the bottom surface of the cubic column.

[0066] 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 condition of the printing green body, as long as the organic matter in the green body is removed to make the inorganic material solidify into a ceramic material. Preferably, the debinding process of the printing green body comprises: heating at a temperature of 400-800°C for 1-10h.

[0067] Further preferably, in step (2), the debinding of the printing green body is divided into two stages:

[0068] The first stage is to increase the temperature at a rate of 3-8°C / min to 450-550°C, and keep for 1-3h, preferably at a rate of 3-7°C / min to 460-530°C, and keep for 1.5-2.5h;

[0069] The second stage is to continue to increase the temperature at a rate of 8-15°C / min to 650-750°C, and keep for 1-3h, preferably at a rate of 8-12°C / min to 680-720°C, and keep for 2-3h.

[0070] 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 keeping the green body structure from being destroyed, and the heating rate is controlled at 3-8°C / min to avoid cracks in the green body due to too fast heating. The second stage increases the heating temperature to make the inorganic material in the printing green body solidify into porcelain.

[0071] According to the present application, preferably, the sintering conditions include: sintering temperature of 1300-1600°C, preferably 1350-1500°C; sintering time of 1-3h, preferably 1.5-2.5h; heating rate of 8-15°C / min, preferably 9-12°C / min. In the present application, under the above sintering conditions, the obtained 3D printed ceramic carrier provides support for subsequent in-situ generation of manganese-based active component layer on the carrier.

[0072] According to the present application, preferably, after sintering, the cooling rate is 3-8°C / min, preferably 4-6°C / min.

[0073] According to the present application, preferably, in step (3), the volume ratio of the 3D printed ceramic carrier to the manganese-based precursor dispersion liquid is 1:8-20, for example 1:8, 1:9, 1:10, 1:12, 1:15, 1:18, 1:20, and any range between any two values, preferably 1:9-15. In the present application, limiting the volume ratio of the 3D printed ceramic carrier to the manganese-based precursor dispersion liquid helps to control the growth rate of the manganese-based active component layer, and a too fast growth rate will cause uneven distribution of the active component, and a too slow growth rate will lead to a too long synthesis time of the catalyst.

[0074] According to the present application, preferably, the conditions of the hydrothermal reaction include: the reaction temperature is 90-160℃, for example, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, and any range consisting of any two values, preferably 110-140℃; the reaction time is 12-24h, for example, 12h, 14h, 16h, 18h, 20h, 22h, 24h, and any range consisting of any two values, preferably 12-18h. The hydrothermal reaction is carried out under the above conditions, so that the manganese-based active component in the manganese-based precursor dispersion liquid can be effectively loaded on the 3D printed ceramic carrier, and the atomic utilization efficiency of the active component is improved.

[0075] According to the present application, preferably, the manganese-based precursor dispersion liquid comprises a manganese salt, an optional M metal soluble salt, and a solvent, wherein the M metal is selected from at least one of Fe, Co, Ni, Cu, and Ce.

[0076] In the present application, preferably, the optional M metal is added to cooperate with the Mn element, which can enhance the redox ability of the catalyst through the near-distance electron transfer process of the M metal and Mn, and the synergistic effect further improves the catalytic oxidation activity of the in-situ grown manganese-based active component layer, and the combination of the 3D printed ceramic carrier with a special structure can realize low-temperature and high-efficiency oxidation of VOCs.

[0077] According to the present application, the type of the manganese salt is not particularly limited, and preferably, the manganese salt is selected from at least one of MnSO4, Mn(NO3)2, MnCl2, and Mn(CH3COO)2.

[0078] According to the present application, preferably, the M metal soluble salt is selected from at least one of the sulfate, nitrate, chloride, and acetate of the M metal.

[0079] According to the present application, preferably, the M metal is selected from at least one of Co, Cu, and Fe. More preferably, the M metal soluble salt is selected from at least one of Co(NO3)2, Cu(NO3)2, and Fe(NO3)2.

[0080] According to the present application, preferably, the total molar concentration of Mn and the optional M metal in the manganese-based precursor dispersion liquid is 0.02-0.2mol / L, for example, 0.02mol / L, 0.04mol / L, 0.06mol / L, 0.08mol / L, 0.1mol / L, 0.12mol / L, 0.14mol / L, 0.16mol / L, 0.18mol / L, 0.2mol / L, and any range consisting of any two values, preferably 0.04-0.16mol / L.

[0081] According to the present application, preferably, the molar ratio of Mn to M metal in the manganese-based precursor dispersion is 1:0-1, such as 1:0, 1:0.02, 1:0.05, 1:0.1, 1:0.2, 1:0.3, 1:0.5, 1:0.8, 1:1, and any range falling between any two of the values, preferably 1:0.02-0.3. In the present application, the molar ratio of Mn to M metal in the manganese-based precursor dispersion is limited within a certain range. If the proportion of M metal is too high, the manganese oxide main structure cannot be maintained, and the redox property of the active component will be greatly reduced.

[0082] According to the present application, preferably, in step (3), a precipitation aid is further added in the hydrothermal reaction, and the ratio of the total molar amount of Mn and M metal to the molar amount of the precipitation aid is 1:1-2.5, such as 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, 1:2.2, 1:2.4, 1:2.5, and any range falling between any two of the values, preferably 1:1.4-2.

[0083] According to the present application, preferably, the precipitation aid is at least one selected from the group consisting of easily hydrolyzable organic amines, soluble carbonates, and soluble bicarbonates, preferably at least one selected from the group consisting of urea, NH4HCO3, and (NH4)2CO3. In the present application, the above-mentioned precipitation aid is added in the hydrothermal reaction, and the amount of the precipitation aid is controlled, so that the loading amount of the manganese-based active component can be controlled, and the manganese-based active component is slowly precipitated after the hydrothermal reaction starts and uniformly loaded on the carrier by in-situ growth. If the amount of the precipitation aid is too small, the Mn element and the M metal element cannot be completely precipitated, and if the amount of the precipitation aid is too large, the material will be wasted.

[0084] In the present application, the equipment for the hydrothermal reaction is not particularly limited, as long as the reaction can be carried out under hydrothermal reaction conditions, and a person skilled in the art can select as needed. According to one preferred embodiment of the present application, the hydrothermal reaction is carried out in a reaction kettle, preferably a Teflon reaction kettle.

[0085] In the present application, preferably, after the hydrothermal reaction is completed, the reaction kettle is cooled (preferably to room temperature) and then opened. This preferred embodiment avoids the safety hazard of opening the kettle at high temperature due to the autogenous pressure in the kettle under the condition of the hydrothermal reaction at elevated temperature.

[0086] Preferably, after the hydrothermal reaction, the 3D-printed ceramic carrier with the in-situ grown manganese-based active component layer is separated and washed. The separation method is not particularly limited and can be adjusted by those skilled in the art as long as the carrier is separated from the manganese-based precursor dispersion. The washing method is not particularly limited and can be adjusted by those skilled in the art according to the washing effect. According to a preferred embodiment of the present application, deionized water is used for washing.

[0087] According to the present application, preferably, in step (3), the calcination conditions include a calcination temperature of 300-650℃, preferably 350-550℃, and a calcination time of 1.5-4h, preferably 2-3.5h.

[0088] According to the present application, preferably, to obtain a manganese-based active component layer with MnO2 as the main phase, the temperature is raised to 300-450℃ at a rate of 1-5℃ / min and maintained for 1.5-4h.

[0089] According to the present application, preferably, to obtain a manganese-based active component layer with Mn2O3 as the main phase, the temperature is raised to 450-650℃ at a rate of 1-5℃ / min and maintained for 1.5-4h.

[0090] In the present application, different phase states of manganese-based active component layers can be obtained by different calcination conditions. When MnO2 is the main phase, the catalyst has strong redox ability but is not resistant to high temperature, and is suitable for treating VOCs with low oxidation difficulty at low temperature. When Mn2O3 is the main phase, the catalyst has high thermal stability and is suitable for treating VOCs with high oxidation difficulty.

[0091] The fourth aspect of the present application provides a manganese-based catalyst prepared by the method of the third aspect.

[0092] According to the present application, preferably, the manganese-based catalyst comprises a 3D-printed ceramic carrier and a manganese-based active component in-situ grown on the 3D-printed ceramic carrier.

[0093] In the present application, preferably, the content of the manganese-based active component layer in-situ grown on the 3D-printed ceramic carrier is 30-150g / L, for example 30g, 40g, 50g, 60g, 70g, 80g, 90g, 100g, 110g, 120g, 130g, 140g, 150g, and any range between any two values, preferably 50-140g / L, based on the volume of the 3D-printed ceramic carrier being 1L. In the present application, the manganese-based active component loaded on the surface of the 3D-printed ceramic carrier replaces the noble metal active component, ensuring excellent catalytic oxidation activity of the catalyst while effectively reducing the cost of the catalyst.

[0094] In the present application, the volume of the 3D-printed ceramic carrier is calculated according to the outer dimensions of the carrier obtained by 3D printing.

[0095] The fifth aspect of the present application provides a use of the manganese-based catalyst of the second aspect or the fourth aspect in catalyzing an oxidation reaction.

[0096] In the present application, preferably, the manganese-based catalyst is used in catalyzing an oxidation reaction of VOCs.

[0097] In the present application, the composition of the VOCs is not particularly limited, and is a volatile organic compound 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.

[0098] In the present application, the use of the manganese-based catalyst in catalyzing an oxidation reaction of VOCs can effectively alleviate the problems of uneven airflow distribution and insufficient residence time of VOCs in the pores of the catalyst, improve the reaction contact conditions, and reduce the VOCs gas conversion temperature.

[0099] In the present application, preferably, the manganese-based catalyst is used in catalyzing an oxidation reaction of alkanes, more preferably, catalyzing an oxidation reaction of propane.

[0100] In the present application, the catalytic oxidation reaction device is not particularly limited, 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.

[0101] In the present application, the reaction conditions of the catalytic oxidation are not particularly limited, and can be adaptively adjusted by those skilled in the art according to the catalytic oxidation reaction. Preferably, the reaction conditions include: the reaction pressure is atmospheric pressure, the reaction temperature is 100-600℃, preferably 200-500℃, the volume space velocity is 1000-80000h -1 , preferably 10000-50000h -1 .

[0102] According to a particularly preferred embodiment of the present application, a preparation method of a manganese-based catalyst prepared by 3D printing comprises the following steps:

[0103] (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;

[0104] (2) performing debinding and sintering on the printing blank to obtain a 3D-printed ceramic carrier;

[0105] (3) hydrothermal reaction of the 3D-printed ceramic carrier in a manganese-based precursor dispersion liquid, and calcination to obtain a manganese-based catalyst;

[0106] The hydrothermal reaction conditions include a reaction temperature of 110-140℃ and a reaction time of 12-18h.

[0107] The molar ratio of Mn to M metal in the manganese-based precursor dispersion liquid is 1:0.02-0.3.

[0108] In step (3), a precipitation aid is further added in the hydrothermal reaction, and the ratio of the total molar amount of Mn and M metal to the molar amount of the precipitation aid is 1:1.4-2.

[0109] The application will be described in detail below through examples and comparative examples. In the following examples and comparative examples, room temperature is 25℃.

[0110] The three-dimensional model is established by 3DMAX.

[0111] The 3D printing is completed by a sinking DLP-3D printer (model SU136A) of Foshan Guanglei Intelligent Manufacturing Co., Ltd.

[0112] The planetary ball mill is a JC-QM series vertical planetary ball mill of JIANGCHUANG Environmental Protection.

[0113] The average particle size of the ceramic powder is the equivalent volume diameter obtained by the laser particle size method, and the test instrument is Malvern Mastersizer 3000.

[0114] Example 1

[0115] (1-1) Preparation of photosensitive resin mixture:

[0116] According to the mass ratio of 1:1.5, epoxy acrylate prepolymer (Foshan Guanglei Intelligent Manufacturing Co., Ltd.) and 1,6-hexanediol diacrylate (HDDA) are mixed, and fully stirred to obtain photosensitive resin. 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide and powder dispersant (Yangzhou Lida Resin Co., Ltd., LD-1241) are added to the photosensitive resin, so that 5 parts of photoinitiator, 92 parts of photosensitive resin and 3 parts of powder dispersant are contained in 100 parts of photosensitive resin mixture. After fully stirring, the photosensitive resin mixture is obtained.

[0117] (1-2) Preparation of photosensitive ceramic slurry:

[0118] The photosensitive resin mixed solution prepared in (1-1) was placed in a high-speed disperser, and the required amount of cordierite powder (Hebei Lingshou County Stone Mine Product Processing Plant, average particle size 4.5 μm) was weighed. The mass ratio of ceramic powder to photosensitive resin mixed solution was 1:1. Slowly pour into the photosensitive resin mixed solution, turn on the high-speed disperser for stirring during the pouring process, and set the stirring speed of the high-speed disperser to 500 rpm. After the ceramic powder is completely poured in, continue stirring for 40 min. The obtained preliminary mixed ceramic slurry is repeatedly ground 4 times using a planetary ball mill, each grinding time is 1 h, and the rotation speed is 300 rpm, to obtain a photosensitive ceramic slurry.

[0119] (1-3) 3D printing:

[0120] The photosensitive ceramic slurry was placed in a material cylinder, a three-dimensional model was introduced, and after slicing, 3D printing was performed to obtain a printed body with a connected channel structure. The printed body has a vertical staggered structure composed of cubic columns with a side length of 1.2 mm, and the shape is a cylinder with a bottom surface diameter of 3 cm and a height of 1 cm. The 3D printing parameters are as follows: single layer solidification thickness 100 μm, single layer light exposure time 10 s, light intensity 5 mW / cm 2 ; the printed body has a similar channel structure. Figure 1

[0121] (2) Printed body debinding and sintering:

[0122] Two-stage heating treatment was adopted for debinding. The first stage was to heat to 500 ℃ at a rate of 5 ℃ / min and maintain for 2 h; the second stage was to continue heating to 700 ℃ at a rate of 10 ℃ / min and maintain for 2 h.

[0123] After the debinding treatment was completed, sintering was continued by heating to 1400 ℃ at a rate of 10 ℃ / min and maintaining for 2 h; then cooling to room temperature at a rate of 5 ℃ / min to obtain a 3D printed ceramic carrier.

[0124] (3-1) In-situ growth of manganese-based active component layer: 1.73 g of an aqueous solution containing 50 wt% Mn(NO3)2 was diluted in 80 mL of deionized water to obtain a manganese-based precursor dispersion, which was transferred to a 100 mL Teflon reaction kettle, 0.58 g of urea was added and stirred for 30 min, the 3D printed ceramic carrier was completely immersed in the manganese-based precursor dispersion, and the reaction kettle was sealed and reacted at 120 ℃ for 12 h. After the reaction was completed, the carrier was separated from the liquid phase and washed with deionized water.

[0125] (3-2) Post-treatment: The 3D printed ceramic carrier with in-situ grown manganese-based active component layer was dried at 120 ℃ for 2 h, then heated to 350 ℃ at a rate of 3 ℃ / min and maintained for 3 h to obtain a manganese-based catalyst, Figure 2 ​A photograph of the manganese-based catalyst prepared in Example 1 was taken, and the manganese-based active component loading is shown in Table 1.

[0126] Example 2

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

[0128] Polyurethane acrylate (Foshan Guangle Intelligent Manufacturing Co., Ltd.) and trimethylolpropane triacrylate (TMPTA) were mixed in a mass ratio of 1:2, and fully stirred to obtain a photosensitive resin. Isopropyl thioxanthone (ITX) and a 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 8 parts of a photoinitiator, 88 parts of a photosensitive resin, and 4 parts of a powder dispersant per 100 parts by weight of the photosensitive resin mixture solution. After being fully stirred, a photosensitive resin mixture solution was obtained.

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

[0130] The photosensitive resin mixture solution prepared in (1-1) was placed in a high-speed disperser, and the required amount of bentonite powder (Hebei Lingshou County Gushi Mineral Product Processing Factory, average particle size 3.6 μm) was weighed and slowly poured into the photosensitive resin mixture solution. The mass ratio of ceramic powder to photosensitive resin mixture solution was 1:1.4. During the pouring process, the high-speed disperser was started to stir. The stirring rate of the high-speed disperser was set to 600 rpm. After the ceramic powder was completely poured, the stirring was continued for 60 min. The obtained preliminary mixed ceramic slurry was repeatedly ground 3 times using a planetary ball mill, with each grinding time being 1.5 h and the rotation speed being 450 rpm, to obtain a photosensitive ceramic slurry.

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

[0132] The ceramic 3D 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 cubic columns with a side length of 1.8 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 125 μm, single layer light exposure time 15 s, light intensity 8 mW / cm 2 .

[0133] (2) Printed body debinding and sintering:

[0134] The two-stage heating treatment was used for debinding. The first stage was to heat to 530℃ at a rate of 7℃ / min and keep for 2h; the second stage was to continue heating to 720℃ at a rate of 12℃ / min and keep for 2.5h. After the debinding treatment was completed, the sintering was continued by heating to 1500℃ at a rate of 10℃ / min and keeping for 1.5h; then the temperature was decreased to room temperature at a rate of 5℃ / min, and the 3D printed ceramic carrier was obtained.

[0135] (3-1) In-situ growth of manganese-based active component layer:

[0136] 1.08g of MnSO4·H2O and 0.15g of Co(NO3)2·6H2O were dissolved in 80mL of deionized water to obtain a manganese-based precursor dispersion, which was transferred to a 100mL Teflon reactor, 0.77g of urea was added and stirred for 30min, the 3D printed ceramic carrier was completely immersed in the manganese-based precursor dispersion, and the reactor was sealed and reacted at 120℃ for 12h. After the reaction was completed, the carrier was separated from the liquid phase and washed with deionized water.

[0137] (3-2) Post-treatment: The 3D printed ceramic carrier with in-situ grown manganese-based active component layer was dried at 120℃ for 2h, then heated to 400℃ at a rate of 3℃ / min and kept for 3h to obtain a manganese-based catalyst. The manganese-based active component loading is shown in Table 1.

[0138] Example 3

[0139] (1-1) Preparation of photosensitive resin mixture:

[0140] Polyurethane acrylate (Foshan Guangle Intelligent Manufacturing Co., Ltd.) and tripropylene glycol diacrylate (TPGDA) were mixed in 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, so that the photosensitive resin mixture contained 3 parts of photoinitiator, 92 parts of photosensitive resin and 5 parts of powder dispersant per 100 parts by weight of photosensitive resin mixture. After fully stirring, a photosensitive resin mixture was obtained.

[0141] (1-2) Preparation of photosensitive ceramic slurry:

[0142] The photosensitive resin mixture obtained in (1-1) was placed in a high-speed disperser. The required amount of kaolin powder (Hebei Lingshou County Gushi Mine Product Processing Plant, average particle size 2.8 μm) was weighed, and slowly poured into the photosensitive resin mixed solution, and the mass ratio of ceramic powder and photosensitive resin mixed solution was 1:0.5. The high-speed disperser was started to stir during the pouring process, and the stirring speed of the high-speed disperser was set to 400 rpm. After the ceramic powder was completely poured in, the stirring was continued for 25 min. The obtained preliminary mixed ceramic slurry was repeatedly ground 5 times using a planetary ball mill, each grinding time was 0.8 h, and the rotation speed was 450 rpm, to obtain a photosensitive ceramic slurry.

[0143] (1-3) 3D printing:

[0144] 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 cubic columns with a side length of 0.8 mm, and the shape was a cylinder with a bottom surface 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 .

[0145] (2) Printed body debinding and sintering:

[0146] Two-stage heating treatment was adopted for debinding. In the first stage, the temperature was raised to 460℃ at a rate of 3℃ / min and maintained for 2h; in the second stage, the temperature was continued to rise to 680℃ at a rate of 8℃ / min and maintained for 3h. After the debinding treatment was completed, the sintering was continued by raising the temperature to 1350℃ at a rate of 10℃ / min and maintaining for 2h; then the temperature was lowered to room temperature at a rate of 5℃ / min.

[0147] (3-1) In-situ growth of manganese-based active component layer: 1.63 g of MnSO4·H2O and 0.56 g of Cu(NO3)2·3H2O were dissolved in 80 mL of deionized water to obtain a manganese-based precursor dispersion, which was transferred to a 100 mL Teflon reaction kettle, 1.08 g of urea was added and stirred for 30 min, the 3D printed ceramic carrier was completely immersed in the manganese-based precursor dispersion, and the reaction kettle was sealed and reacted at 120℃ for 12 h. After the reaction was completed, the carrier was separated from the liquid phase and washed with deionized water.

[0148] (3-2) Post-treatment: The 3D printed ceramic carrier with in-situ grown manganese-based active component layer was dried at 120℃ for 2h, and then the temperature was raised to 500℃ at a rate of 3℃ / min and maintained for 3h to obtain a manganese-based catalyst. The manganese-based active component loading is shown in Table 1.

[0149] Example 4

[0150] The manganese-based catalyst was prepared according to the method of Example 3, except that in step (3), 0.77 g of urea was added, and other conditions were the same as those of Example 3, to obtain the manganese-based catalyst, and the manganese-based active component loading amount is shown in Table 1.

[0151] Example 5

[0152] The manganese-based catalyst was prepared according to the method of Example 3, except that in step (3), the hydrothermal reaction conditions were a reaction temperature of 90°C and a reaction time of 11 h, to obtain the manganese-based catalyst, and the manganese-based active component loading amount is shown in Table 1.

[0153] Example 6

[0154] The manganese-based catalyst was prepared according to the method of Example 3, except that in step (3), no urea was added, to obtain the manganese-based catalyst, and the manganese-based active component loading amount is shown in Table 1.

[0155] Example 7

[0156] The manganese-based catalyst was prepared according to the method of Example 3, except that in step (3), 1.01 g of MnSO4·H2O and 1.45 g of Cu(NO3)2·3H2O were dissolved in 80 mL of deionized water to obtain a manganese-based precursor dispersion liquid, the amount of urea was adjusted, the ratio of the total molar amount of Mn and M metals to the molar amount of urea was the same as that of Example 3, and other conditions were the same as those of Example 3, to obtain the manganese-based catalyst, and the manganese-based active component loading amount is shown in Table 1.

[0157] Example 8

[0158] (1) The carrier was a customized commercial cordierite carrier (Jiangxi Guocui Environmental Technology Co., Ltd., ceramic honeycomb carrier), with a bulk density of 0.5 kg / L, a pore volume of 0.5 mL / g, and a single cubic column straight pore in the interior; it was cut into a cylinder with a bottom surface diameter of 3 cm and a height of 1 cm.

[0159] (2) The manganese-based active component layer was in-situ grown and post-processed according to the method of step (3) of Example 3, to obtain the manganese-based catalyst, and the manganese-based active component loading amount is shown in Table 1.

[0160] Comparative Example 1

[0161] (1) Steps (1) and (2) were performed according to the method of Example 3;

[0162] (2) MnO2 powder was added to deionized water, and 63% concentrated nitric acid was then added to adjust the system to a pH of less than 4. A vibration type ball mill (Tianjin Shengyuan Equipment Co., Ltd., GZM-6) was used to fully grind the above mixture, and the grinding conditions were as follows: ball milling time of 3 h and rotation speed of 800 rpm, to obtain MnO2 particles with an average diameter of 8 μm in the mixture, and the MnO2 content in the mixture was 15 wt%.

[0163] (3) The mixed solution after grinding was uniformly coated on the surface of the 3D printed ceramic carrier, and drying and calcination were performed, and the total coating amount of the coating on each liter of the 3D printed ceramic carrier was 60 g / L, the drying and calcination conditions were the same as in Example 3, and the loading amount of the manganese-based active component was shown in Table 1.

[0164] Comparative Example 2

[0165] (1) A customized commercial cordierite carrier (Jiangxi Guocui Environmental 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 single cubic column straight channels inside, which was cut into a cylinder with a bottom diameter of 3 cm and a height of 1 cm;

[0166] (2) A certain amount of Al2O3 powder was added to deionized water, and then 63% concentrated nitric acid was added to adjust the system to a pH less than 4, and a vibration type ball mill (Tianjin Shengyuan Equipment Co., Ltd., GZM-6) was used to fully grind the above-mentioned mixed solution, and the grinding conditions were as follows: ball milling time 1.5 h, rotation speed 1200 rpm. The average diameter of Al2O3 particles in the mixed solution after grinding was 12.5 μm. After stirring the mixed solution after grinding for 2 hours, a certain amount of noble metal Na2PdCl4 solution was added, and stirring was continued for 2 hours to prepare a catalyst slurry, and the solid content of the slurry was controlled to be 15 wt%.

[0167] (3) The catalyst slurry was coated on the carrier of step (1), and the total loading amount of the active component in the coating was 22 g / L, of which the Pd content was 0.15 g / L, and the rest was Al2O3. After coating, post-treatment was performed, and the post-treatment conditions were the same as in Example 3, and the active component loading amount was shown in Table 1.

[0168] Comparative Example 3

[0169] (1) A customized commercial cordierite carrier (Jiangxi Guocui Environmental 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 single cubic column straight channels inside, which was cut into a cylinder with a bottom diameter of 3 cm and a height of 1 cm;

[0170] (2) A certain amount of MnO2 powder was added to deionized water, and then 63% concentrated nitric acid was added to adjust the mixed solution to a pH less than 4, and a vibration type ball mill (Tianjin Shengyuan Equipment Co., Ltd., GZM-6) was used to fully grind the above-mentioned mixed solution, and the specific grinding conditions were as follows: ball milling time 3 h, rotation speed 800 rpm. The average diameter of MnO2 particles in the mixed solution after grinding was 8 μm, and the solid content of the slurry was controlled to be 15 wt%.

[0171] (3) The mixed solution was uniformly coated on the surface of the commercial cordierite carrier, and post-treatment was performed, and the post-treatment was the same as in Example 3, and the loading amount of the manganese-based active component was shown in Table 1.

[0172] Comparative Example 4

[0173] (1) The photosensitive ceramic slurry was prepared according to the conditions of steps (1-1) and (1-2) in Example 3;

[0174] (2) 1.73 g of an aqueous solution containing 50 wt% Mn(NO3)2was diluted in 80 mL of deionized water to obtain a manganese-based precursor dispersion, and the manganese-based precursor dispersion prepared was mixed with the photosensitive ceramic slurry in step (1), and the mixing conditions were as follows: the mass ratio of the manganese-based precursor dispersion to the photosensitive ceramic slurry was 1:20, to obtain a mixed slurry;

[0175] (3) The mixed slurry was subjected to 3D printing, and a catalyst precursor was obtained by 3D printing, and the catalyst precursor was calcined under the same conditions as in Example 3.

[0176] Test Example

[0177] The catalytic oxidation activity of the catalyst was evaluated by a catalytic oxidation reaction of propane, which was completed on a micro fixed bed reaction device designed and manufactured by Tianjin Pengxiang Technology Co., Ltd., which was equipped with a Multigas 2030 type infrared detector of MKS company. The reaction was carried out at normal pressure, and the initial temperature was 250°C, which was programmed to 500°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. The results are shown in Table 1. -1

[0178] The active component loading was calculated based on the mass of manganese oxide and metal oxide.

[0179] Table 1

[0180] No. Propane T 50 (°C) Propane T 90 (°C) Active ingredient loading (g / L) Example 1 332.5 420.3 61 Example 2 320.1 406.2 88 Example 3 301.3 390.5 132 Example 4 312.7 402.3 97 Example 5 329.4 420.7 75 Example 6 342.5 432.2 24 Example 7 325.1 412.5 128 Example 8 338.7 422.4 120 Comparative Example 1 350.6 451.2 60 Comparative Example 2 413.5 >500 22 (Pd + Al203) Comparative Example 3 386.5 480.6 26 Comparative Example 4 >500 >500 0 (no coating)

[0181] Note: T 50 is the temperature corresponding to 50% propane conversion, T 90 is the temperature corresponding to 90% propane conversion, and the propane conversion rate = 1- (residual propane content / propane raw material content) x 100%.

[0182] As can be seen from the results in Table 1, the example of growing manganese-based active components in situ on a regular carrier according to the present application has a better effect than the traditional cordierite carrier coated with manganese-based active components, and the effect is better than the traditional cordierite supported noble metal Pd catalyst, which can significantly reduce the propane conversion temperature. Compared with the traditional regular carrier, the 3D printed carrier has three-dimensional interconnected channels, which can further improve the catalytic oxidation activity, and at the same propane conversion rate, the conversion temperature is lower.

[0183] ​The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including that each technical feature is combined in any other suitable manner. 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 preparing a manganese-based catalyst using 3D printing, characterized in that, Includes the following steps: (1) The photosensitive resin mixture is mixed with ceramic powder to obtain a photosensitive ceramic slurry, which is then used for 3D printing to obtain a printed blank; (2) The printed blank is degreased and sintered to obtain a 3D printed ceramic carrier; (3) The 3D printed ceramic carrier is subjected to a hydrothermal reaction in a manganese-based precursor dispersion and calcined to obtain a manganese-based catalyst; Based on a mass of 100 parts of photosensitive resin mixture, it includes 1-12 parts of photoinitiator, 82-92 parts of photosensitive resin, and 3-7 parts of powder dispersant; The photosensitive resin is a mixture of acrylate prepolymer and acrylate monomer, wherein the acrylate prepolymer is an epoxy acrylate prepolymer and / or a polyurethane acrylate prepolymer; The printed blank has a vertically interlaced structure composed of cubic prisms with a base length of 0.5-2mm.

2. The method according to claim 1, wherein, The photosensitive resin mixture comprises 3-8 parts photoinitiator, 88-92 parts photosensitive resin, and 3-5 parts powder dispersant, with a mass of 100 parts.

3. The method according to claim 1, wherein, The photoinitiator is selected from at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and isopropylthioxanthrone.

4. The method according to claim 1, wherein, The mass ratio of acrylate prepolymer to acrylate monomer in photosensitive resin is 1:0.5-2.

3.

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

5.

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

5.

7. The method according to claim 6, wherein, In step (1), the mass ratio of the ceramic powder and the photosensitive resin mixture is 1:0.5-1.

4.

8. The method according to claim 1, wherein, The ceramic powder is a natural mineral clay of aluminosilicate type; And / or, the average particle size of the ceramic powder is less than 10 μm.

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

10. The method according to any one of claims 1-9, wherein, The conditions for 3D printing include: a single-layer curing thickness of 20-150 μm, a single-layer illumination time of 5-20 s, and an illumination intensity of 2-10 mW / cm². 2 .

11. The method according to any one of claims 1-9, wherein, In step (2), the degreasing process of the printed blank includes: heating temperature of 400-800℃ and heating time of 1-10h.

12. The method according to claim 11, wherein, The degreasing of the printed blank is divided into two stages: the first stage involves heating to 450-550℃ at a rate of 3-8℃ / min and maintaining the temperature for 1-3 hours; In the second stage, the temperature is increased to 650-750℃ at a rate of 8-15℃ / min and maintained for 1-3 hours.

13. The method according to claim 12, wherein, The degreasing of the printed preform is divided into two stages: the first stage involves heating to 460-530℃ at a rate of 3-7℃ / min and maintaining the temperature for 1.5-2.5 hours; In the second stage, the temperature is increased to 680-720℃ at a rate of 8-12℃ / min and maintained for 2-3 hours.

14. The method according to any one of claims 1-9, wherein, The sintering conditions include: a sintering temperature of 1300-1600℃; a sintering time of 1-3h; and a heating rate of 8-15℃ / min.

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

16. The method according to any one of claims 1-9, wherein, After sintering, the temperature is cooled to room temperature at a rate of 3-8℃ / min.

17. The method according to claim 16, wherein, After sintering, the temperature is cooled to room temperature at a rate of 4-6℃ / min.

18. The method according to any one of claims 1-9, wherein, In step (3), the volume ratio of the 3D printed ceramic carrier to the manganese-based precursor dispersion is 1:8-20.

19. The method according to claim 18, wherein, In step (3), the volume ratio of the 3D printed ceramic carrier to the manganese-based precursor dispersion is 1:9-15.

20. The method according to any one of claims 1-9, wherein, The conditions for the hydrothermal reaction include: a reaction temperature of 90-160℃ and a reaction time of 12-24h.

21. The method according to claim 20, wherein, The conditions for the hydrothermal reaction include: a reaction temperature of 110-140℃ and a reaction time of 12-18h.

22. The method according to any one of claims 1-9, wherein, The manganese-based precursor dispersion comprises a manganese salt, an optional M metal soluble salt, and a solvent, wherein the M metal element is selected from at least one of Fe, Co, Ni, Cu, and Ce.

23. The method according to claim 22, wherein, The manganese salt is selected from at least one of MnSO4, Mn(NO3)2, MnCl2 and Mn(CH3COO)2; And / or, the soluble salt of metal M is selected from at least one of the sulfate, nitrate, chloride and acetate of metal M.

24. The method according to claim 23, wherein, The metal M is selected from at least one of Co, Cu and Fe.

25. The method according to claim 22, wherein, The total molar concentration of Mn and optionally M metal in the manganese-based precursor dispersion is 0.02-0.2 mol / L; And / or, the molar ratio of Mn to M metal in the manganese-based precursor dispersion is 1:0-1.

26. The method of claim 25, wherein, The total molar concentration of Mn and optionally M metal in the manganese-based precursor dispersion is 0.04-0.16 mol / L; And / or, the molar ratio of Mn to M metal in the manganese-based precursor dispersion is 1:0.02-0.

3.

27. The method according to any one of claims 1-9, wherein, In step (3), a precipitation aid is also added to the hydrothermal reaction, and the ratio of the total molar amount of Mn and M metal to the molar amount of the precipitation aid is 1:1-2.

5.

28. The method according to claim 27, wherein, In step (3), the ratio of the total molar amount of Mn and M metals to the molar amount of precipitation aid is 1:1.4-2.

29. The method according to claim 27, wherein, The precipitation aid is selected from at least one of easily hydrolyzable organic amines, soluble carbonates, and soluble bicarbonates.

30. The method according to claim 29, wherein, The precipitation aid is selected from at least one of urea, NH4HCO3 and (NH4)2CO3.

31. The method according to any one of claims 1-9, wherein, In step (3), the roasting conditions include: roasting temperature of 300-650℃; roasting time of 1.5-4h.

32. The method according to claim 31, wherein, To obtain a manganese-based active component layer with MnO2 as the main phase, the temperature was increased to 300-450℃ at a rate of 1-5℃ / min and held for 1.5-4h. And / or, to obtain a manganese-based active component layer with Mn2O3 as the main phase, the temperature is increased to 450-650℃ at a rate of 1-5℃ / min and held for 1.5-4h.

33. The manganese-based catalyst prepared by the method according to any one of claims 1-32.

34. The manganese-based catalyst according to claim 33, wherein, The manganese-based catalyst comprises a 3D-printed ceramic support and a manganese-based active component grown in situ on the 3D-printed ceramic support.

35. The use of the manganese-based catalyst according to claim 33 or 34 in catalytic oxidation reactions.

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