Alumina catalyst with metal single-atom supported biomimetic bicontinuous amplitude modulation decomposition structure, and preparation method and application thereof

Abstract

The present application relates to a metal monatomic loaded bionic bicontinuous amplitude modulation decomposition structure alumina catalyst and a preparation method and application thereof. The metal monatomic loaded bionic bicontinuous amplitude modulation decomposition structure alumina catalyst of the present application comprises an alumina catalyst framework, wherein the alumina catalyst framework has a bicontinuous amplitude modulation decomposition structure; and metal monatomic atoms loaded on the alumina catalyst framework. The metal monatomic loaded bicontinuous amplitude modulation decomposition structure alumina catalyst of the present application has a high specific surface area and rich surface active sites, high catalytic activity and stability, and can be efficiently recycled for ozone catalytic oxidation water treatment. The present application also provides a general preparation method of the metal monatomic loaded bicontinuous amplitude modulation decomposition structure alumina catalyst.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of catalytic materials and water treatment, and particularly relates to a metal monatomic loaded bionic double-continuous amplitude modulation decomposition structure alumina catalyst and a preparation method and application thereof. BACKGROUND

[0002] Oxides such as alumina and zirconia have the advantages of strong structural stability, stable chemical properties, convenient recycling and the like, and are therefore widely used in the preparation process of catalysts. However, the surface activity of oxides is generally low, and the introduction of amorphous carbon structures and other active components on the stable surface of the oxides can increase the surface area and reaction active sites of the materials while taking into account the stable mechanical structure, thereby greatly improving the catalytic performance of the catalysts.

[0003] In the preparation process of traditional oxide-based catalysts, spherical granular oxides are usually used. However, spherical granular oxides have a high water infiltration rate only in a few microns of shallow pore depth, and the internal pore structure is isolated and discontinuous, thereby resulting in a large amount of regions lacking coverage of catalytically active sites and being wasted. Traditional oxide ceramics have problems such as difficulty in integration, complication and precision rapid manufacturing. With the continuous development of 3D printing technology, alumina ceramics with more complex geometric configurations can be prepared by a 3D printing method. According to the different printing technologies, the 3D printing method can be divided into powder sintering forming technology (including selective laser sintering technology SLS, selective laser melting technology SLM and the like), extrusion forming technology (including fused deposition modeling technology FDM, slurry direct writing technology DIW and the like) and photosensitive polymerization forming technology (including digital light processing technology DLP, two-photon polymerization technology TPP and the like) and the like. Compared with the SLM method which has high energy consumption and complex process, and the line scanning DIW method which has low precision and low efficiency, the DLP method significantly reduces the processing steps and energy consumption by face projection of ultraviolet light to initiate polymerization in the specified area and layer-by-layer stacking, and has higher printing efficiency and precision, and is an ideal printing technology for ceramics.

[0004] In addition, the conventional metal-supported catalyst preparation method often causes the active metal component to form clusters on the surface of the catalyst, and the active sites formed by the metal atoms cannot be fully utilized, and the overall catalytic activity needs to be improved. For example, patent document 1 discloses an Al2O3-based carrier monolithic catalyst with a Ni-supported TPMS structure and a preparation method thereof. The catalyst has high mass transfer and heat transfer efficiency, easy sample recovery, good reusability, and can be used for CO methanation, but the distribution of the active component Ni loaded by the general impregnation method is not uniform, the utilization rate of metal atoms is low, and the overall reaction activity needs to be improved. And the mechanical compression resistance of the material cannot be fully improved during the preparation process, which will be limited to some extent during use. In addition, the pore structure inside the catalyst in patent document 1 is isolated, and the chemical reaction sites cannot be said to be sufficient.

[0005] Solving a large amount of industrial wastewater discharge is a difficult problem in front of high-quality green economic development. Among them, industrial wastewater is mostly high-concentration and difficult-to-degrade organic wastewater, and the water quality composition is complex. Traditional biochemical treatment is one of the main process units for treating difficult-to-degrade organic wastewater, but the biochemical wastewater still contains complex and difficult-to-degrade organic matter. Combined with deep treatment methods such as ozone catalytic oxidation technology, further removal of difficult-to-degrade pollutants is an important means to realize wastewater deep purification and resource utilization.

[0006] Therefore, it is urgent to develop a catalyst with multiple reaction sites and hierarchical pore structure, high mass transfer efficiency and catalytic activity, and can be recycled and reused, which can be widely used in the deep treatment of industrial wastewater.

[0007] CITED LITERATURE

[0008] Patent document 1: CN118925731A SUMMARY

[0009] Problem to be solved by the invention

[0010] In view of the problems of the traditional spherical particle catalyst, such as lack of internal pore structure, low surface area utilization, easy agglomeration of the loaded metal catalyst, uneven distribution of catalytic active sites, and difficult to reuse, an alumina-based catalyst with high specific surface area, rich and uniform distribution of catalytic active sites, high stability, and recyclability is needed.

[0011] Solution for solving the problem

[0012] The internal microstructure of various biomaterials in nature, such as butterflies, trees, ram's horns and bones, has different pore sizes, pore shapes and directional preferences. The spinodoid metamaterials represented by the spinodal decomposition structure formed in phase separation have excellent mechanical properties of high strength and high toughness, and also have the characteristics of light weight, continuous smoothness, randomness and defect insensitivity.

[0013] Inspired by the technology, to solve the above problems, the bionic double-continuous spinodal structure alumina-based material is prepared by using 3D printing technology in combination with the bionic idea in the application, and the atomic-level dispersed metal monatomic catalyst is loaded on the basis, so that the alumina catalyst with the metal monatomic catalyst loaded double-continuous spinodal structure is prepared, which has super-high atomic utilization efficiency, multi-pore structure, mass transfer efficiency and catalytic efficiency, good stability and can be recycled.

[0014] The application provides a metal monatomic catalyst loaded bionic double-continuous spinodal structure alumina catalyst, which comprises:

[0015] An alumina catalyst skeleton, wherein the alumina catalyst skeleton has a double-continuous spinodal structure; and a metal monatomic catalyst loaded on the alumina catalyst skeleton.

[0016] According to the catalyst described above, the metal monatomic catalyst is selected from one or more of manganese, iron, nickel and cobalt;

[0017] The loading amount of the metal monatomic catalyst is 0.03-5wt%.

[0018] According to the catalyst described above, the double-continuous spinodal structure is an isotropic spinodal structure, a layered anisotropic spinodal structure, a columnar anisotropic spinodal structure or a cubic anisotropic spinodal structure.

[0019] According to the catalyst described above, the overall structure size of the double-continuous spinodal structure is (2-20) mm x (2-20) mm x (2-20) mm; and the relative density of the double-continuous spinodal structure is 20-80%.

[0020] According to the catalyst described above, the porosity of the alumina catalyst skeleton is 20%-80%.

[0021] The specific surface area of the alumina catalyst skeleton is 10m 2 / g-200m 2 / g.

[0022] The compressive strength of the alumina catalyst framework is 5-300 MPa.

[0023] The application also provides a preparation method of the metal monatomic supported bicontinuous amplitude modulation decomposition structure alumina catalyst, comprising the following steps:

[0024] (1) obtaining a bicontinuous amplitude modulation decomposition structure alumina catalyst framework precursor by 3D printing through face projection microstereolithography technology;

[0025] (2) performing debinding sintering on the bicontinuous amplitude modulation decomposition structure alumina catalyst framework precursor to obtain a bicontinuous amplitude modulation decomposition structure alumina catalyst framework;

[0026] (3) preparing an impregnation solution containing a metal salt for forming a metal monatomic, a zinc salt and 2-methylimidazole, placing the bicontinuous amplitude modulation decomposition structure alumina catalyst framework in the impregnation solution, and performing ultrasonic impregnation, standing and filtering to obtain a metal monatomic supported bicontinuous amplitude modulation decomposition structure alumina catalyst precursor;

[0027] (4) performing a post-treatment process on the metal monatomic supported bicontinuous amplitude modulation decomposition structure alumina catalyst precursor to obtain the metal monatomic supported bicontinuous amplitude modulation decomposition structure alumina catalyst.

[0028] According to the preparation method described above, in step (1),

[0029] determining a three-dimensional geometric model file having a bicontinuous amplitude modulation decomposition structure in a three-dimensional design software; pouring alumina slurry into a liquid tank of a 3D printer, importing the three-dimensional geometric model file into a computer connected to the 3D printer for slicing, and then performing 3D printing by layer-by-layer curing under ultraviolet light;

[0030] wherein the layer thickness of the slice is 10-30 μm; and the exposure time of each layer is 2-10 seconds;

[0031] the wavelength of the ultraviolet light is 300-450 nm; and the light intensity of the ultraviolet light is 2-50 mW / cm 2 .

[0032] According to the preparation method described above, in step (2), the debinding sintering comprises the following three stages:

[0033] Stage one: performing debinding, holding and cooling to room temperature on the bicontinuous amplitude modulation decomposition structure alumina catalyst framework precursor to obtain catalyst framework precursor-I;

[0034] The first stage is performed in a vacuum environment, the defatting rate is 0.5-5℃ / min, the defatting temperature is 400-800℃, and the holding time is 160-220 min.

[0035] The second stage is defatting, holding and cooling to room temperature of the catalyst framework precursor I to obtain a catalyst framework precursor II.

[0036] The second stage is performed in an air environment, the defatting rate is 0.5-5℃ / min, the defatting temperature is 800-1200℃, and the holding time is 20-80 min.

[0037] The third stage is sintering, holding and cooling to room temperature of the catalyst framework precursor II to obtain an alumina catalyst framework with a bicontinuous spinodal decomposition structure.

[0038] The third stage is performed in an air environment, the sintering rate is 2-8℃ / min, the sintering temperature is 1400-1800℃, and the holding time is 40-120 min.

[0039] According to the preparation method described above, in step (3),

[0040] The molar ratio of the metal salt, zinc salt and 2-methylimidazole is (0.1-10 mmol):(1-20 mmol):(10-120 mmol).

[0041] The metal salt is an acetylacetone salt of manganese, iron, nickel or cobalt; and the zinc salt is selected from one or more of zinc acetate, zinc nitrate, zinc chloride, zinc sulfate and zinc carbonate.

[0042] The ultrasonic immersion time is 10-120 min, and the standing time is 12-96 hours.

[0043] According to the preparation method described above, in step (4), the post-treatment process includes drying, oxygen-free roasting, holding and cooling to room temperature.

[0044] The drying temperature is 40-80℃, and the drying time is 10-60 min.

[0045] The roasting rate is 1-5℃ / min, the roasting temperature is 800-1200℃, and the holding time is 1-5 hours.

[0046] The roasting rate is 1-5℃ / min, the roasting temperature is 800-1200℃, and the holding time is 1-5 hours.

[0047] The application further provides application of the metal monatomic loaded bionic bicontinuous amplitude modulation decomposition structure alumina catalyst or the metal monatomic loaded bionic bicontinuous amplitude modulation decomposition structure alumina catalyst obtained by the preparation method to sewage treatment, preferably to ozone catalytic oxidation water treatment.

[0048] Effects of the invention

[0049] 1、The application obtains bionic inspiration of amplitude modulation decomposition structure from the microstructure of natural organisms, and constructs a bionic bicontinuous amplitude modulation decomposition structure including isotropic, anisotropic (layered), anisotropic (columnar) and various configurations, which has the characteristics of high specific surface area, lightweight, high strength, continuous smoothness, structure-pore biphase continuity and defect insensitivity, and overcomes the problems of isolated and discontinuous internal channel structure of the current traditional spherical granular catalyst and lack of catalytic active sites in a large area.

[0050] 2、The application uses face projection microstereolithography technology to realize rapid 3D printing preparation of the alumina catalyst skeleton, and has high printing resolution of microns, solves the problems of high energy consumption, low efficiency and insufficient preparation precision of the current alumina material preparation, meets the development needs of green, low carbon and environmental protection, and realizes a sustainable green manufacturing mode.

[0051] 3、The application successfully loads metal active components on the bionic bicontinuous amplitude modulation decomposition structure alumina catalyst skeleton, and successfully realizes the dispersed form of metal monatomic atoms, and prepares a monolithic metal monatomic loaded alumina catalyst with high catalytic efficiency, which can be recycled and utilized, overcomes the disadvantages that the existing ozone catalysts are difficult to simultaneously consider high catalytic efficiency and recyclability, and creates a prerequisite for subsequent large-scale green and sustainable application.

[0052] 4、The metal monatomic loaded bionic bicontinuous amplitude modulation decomposition structure alumina catalyst prepared has a unique channel structure, and through fluid mechanics mass transfer simulation analysis, can effectively improve the overall mass transfer efficiency; at the same time, the active sites in the form of monatomic atoms greatly improve the atom utilization rate and promote the improvement of reaction activity. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 It is a flowchart for preparing the metal monatomic loaded bicontinuous amplitude modulation decomposition structure alumina catalyst in the application.

[0054] Figure 2 It is a schematic diagram for generating different amplitude modulation decomposition structure models by using a Gaussian random field in the application.

[0055] Figure 3a) and b) are block lattice structure and alumina catalyst skeleton model with different amplitude decomposition structure and their mass transfer performance simulation diagram.

[0056] Figure 4 Temperature control curve for the alumina catalyst skeleton precursor debinding and sintering process in Example 1.

[0057] Figure 5 a) and b) are real photos of the alumina catalyst skeleton precursor and manganese monatomic supported alumina catalyst obtained in Example 1, Comparative Example 1 and Comparative Example 3, respectively.

[0058] Figure 6 Uniaxial compression stress-strain curve diagram of the alumina catalyst skeleton sample obtained at each stage in Example 1.

[0059] Figure 7 Scanning electron microscope diagram of the catalyst prepared in Example 1.

[0060] Figure 8 a) and b) are surface active site property test diagrams of the catalyst prepared in Example 1, the catalyst prepared in Comparative Example 2 and pure nano-carbon catalyst.

[0061] Figure 9 Experimental device diagram for the ozone catalytic oxidation sewage treatment in Example 2-3.

[0062] Figure 10 Degradation curve and degradation kinetic constant fitting diagram for the ozone catalytic oxidation sewage treatment in Example 2.

[0063] Figure 11 Degradation curve diagram and degradation kinetic constant diagram for the ozone catalytic oxidation sewage treatment in the quenching reaction in Example 3. DETAILED DESCRIPTION

[0064] Various exemplary embodiments, features, and aspects of the present application will be described in detail below. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0065] In addition, for the purpose of better illustrating the present application, numerous specific details are given in the following detailed description. One skilled in the art will understand, however, that the application can be practiced without some or all of these specific details. In other instances, well-known methods, apparatuses, materials and steps have not been described in detail in order to avoid obscuring the application.

[0066] Unless otherwise specified, the units used in the present specification are international standard units, and the numerical values, numerical value ranges appearing in the present application should be understood as including systematic errors that are inevitable in industrial production.

[0067] In the present specification, the meaning indicated by "may" includes both the meaning of performing a certain process and the meaning of not performing the certain process.

[0068] In the present specification, "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", and the like refer to specific elements (for example, features, structures, properties, and / or characteristics) described in relation to the embodiments being included in at least one of the embodiments described herein, and can or can not be present in other embodiments. In addition, it should be understood that the elements can be combined in various embodiments in any suitable manner.

[0069] In the present specification, the numerical value range indicated by "numerical value A to numerical value B" refers to a range including the end point numerical values A, B.

[0070] "Room temperature" in the present specification is 15-30°C.

[0071] The present application provides an alumina catalyst with a biomimetic bicontinuous amplitude modulation decomposition structure loaded with metal monomers, which comprises:

[0072] an alumina catalyst framework having a bicontinuous amplitude modulation decomposition structure; and

[0073] metal monomers loaded on the alumina catalyst framework.

[0074] The present application also provides a preparation method of the aforementioned alumina catalyst with a bicontinuous amplitude modulation decomposition structure loaded with metal monomers, which comprises the following steps:

[0075] (1) obtaining an alumina catalyst framework precursor with a bicontinuous amplitude modulation decomposition structure by 3D printing through face projection microstereolithography technology;

[0076] (2) performing debinding sintering on the alumina catalyst framework precursor with a bicontinuous amplitude modulation decomposition structure to obtain an alumina catalyst framework with a bicontinuous amplitude modulation decomposition structure;

[0077] (3) preparing an impregnation solution containing a metal salt, a zinc salt, and 2-methylimidazole for forming metal monomers, placing the alumina catalyst framework with a bicontinuous amplitude modulation decomposition structure in the impregnation solution, ultrasonic impregnation, standing, and filtering to obtain an alumina catalyst precursor with a bicontinuous amplitude modulation decomposition structure loaded with metal monomers;

[0078] (4) subjecting the metal monatomic-loaded bicontinuous amplitude-splitting structure alumina catalyst precursor to a post-treatment process to obtain the metal monatomic-loaded bicontinuous amplitude-splitting structure alumina catalyst.

[0079] Figure 1 A flowchart for preparing the metal monatomic-loaded bicontinuous amplitude-splitting structure alumina catalyst comprises the steps of 3D printing a bicontinuous amplitude-splitting structure alumina catalyst skeleton precursor using a face projection microstereolithography technology, debinding and sintering, ultrasonic loading and oxygen-free calcination, etc.

[0080] The following describes each step in detail.

[0081] Step 1)

[0082] A three-dimensional geometric model file is obtained by generating a biphase continuous, random and isotropic and adjustable anisotropic amplitude-splitting structure through a Gaussian random field (GRF) method. Figure 1 As shown in FIG. 1, the alumina slurry is poured into a liquid tank of a face projection microstereolithography printer, the three-dimensional geometric model file is imported into a computer connected to the face projection microstereolithography 3D printer and sliced, and the face projection microstereolithography technology is used to perform 3D printing under ultraviolet light layer by layer curing. The printed alumina ceramic model (printed structure in FIG. 2) is removed from the sacrificial layer, and the residual slurry inside the structure is removed by ultrasonic cleaning and water flow washing. After cleaning, it is naturally dried to obtain a bicontinuous amplitude-splitting structure alumina catalyst skeleton precursor. Figure 1

[0083] The alumina ceramic model obtained in the printing process comprises a bicontinuous amplitude-splitting structure alumina catalyst skeleton precursor (structure layer) and a sacrificial layer. The sacrificial layer refers to the part removed after printing is completed, and the sacrificial layer plays a role of supporting complex structures and preventing structure collapse during printing.

[0084] In the present application, the metal monatomic is selected from one or more of manganese, iron, nickel and cobalt.

[0085] In the present application, the loading amount of the metal monatomic is 0.05-5.0wt%, for example, it can be 0.1wt%, 0.5wt%, 1.0wt%, 1.2wt%, 1.5wt%, 1.8wt%, 2.0wt%, 2.4wt%, 2.5wt%, 3.0wt%, 3.5wt%, 4.0wt%, 4.5wt% and the like.

[0086] ​In the present application, when the metal active component is loaded in the form of single atoms, the utilization rate of metal atoms can be maximized, the loss of active sites caused by metal clusters can be avoided, and the reaction activity and efficiency of the catalyst can be greatly improved.

[0087] In some specific embodiments of the present application, the bicontinuous amplitude decomposition structure is an isotropic amplitude decomposition structure, a lamellar anisotropic amplitude decomposition structure, a columnar anisotropic amplitude decomposition structure or a cubic anisotropic amplitude decomposition structure.

[0088] Figure 2 A schematic diagram for generating different amplitude decomposition structure models using a Gaussian random field is shown in the figure. The numerical generation formula of the Gaussian random field is as follows:

[0089]

[0090] where φ(x) is a phase field function, representing the concentration fluctuation characteristics of a certain phase at position x in a three-dimensional region Ω, N is the superposition wave number, and κ is the wave number scalar, which can be used to represent the characteristic size of the generated phase field. i and μ i represent the sampling direction and phase shift angle of the i-th wave vector, respectively, both of which are independently sampled from a uniform probability distribution. The anisotropy of this model can be controlled by the Orientation Distribution Functions (ODFs), which limit the sampling of wave vectors to three orthogonal directions defined by the angular range (represented by the angle parameters θ1, θ2 and θ3). When using the ODF sampling of the unit sphere uniform distribution (i.e. θ3 = π / 2), an isotropic microstructure can be obtained. By adjusting the axial constraint angle range, controllable design of anisotropy can be achieved: for example, a lamellar structure corresponds to the parameter setting of θ1 = θ2 = 0, 0 < θ3 < π / 2, a columnar structure corresponds to the parameter setting of 0 < θ1, θ2 < π / 2, θ3 = 0, and a cubic structure can be generated by any parameter combination of 0 < θ1, θ2, θ3 < π / 2. During the phase field evolution process, the initially randomly distributed φ(x) will undergo phase separation to form bicontinuous phase domains separated by smooth interfaces. The amplitude decomposition structure can be obtained by selecting the regions enclosed by two different equal-value surfaces of φ(x), and the relative density of the structure can be adjusted by selecting the values of the different equal-value surfaces. In summary, by numerically adjusting the parameters of the Gaussian random field generation equation, amplitude decomposition structures with different geometric configurations (controlling the sampling angles θ1, θ2 and θ3 of the wave vector n i ), different relative densities (controlling the values of the equal-value surfaces of φ(x)), different pore sizes (controlling the characteristic size κ) and different deflection angles (controlling the phase shift angle μ i ) can be obtained.

[0091] In the present application, isotropic amplitude decomposition structure, layered anisotropic amplitude decomposition structure and columnar anisotropic amplitude decomposition structure are generated by using Gaussian random field method, and the surface area, permeability and mass transfer performance of the designed structure are calculated by using CAD software and finite element analysis software, and the results are shown in Figure 3 a) and b) of FIG.

[0092] Figure 3 a) of FIG. shows the finite element simulation results of the alumina catalyst skeleton precursor model and the vertical section of different structures, and the simulation results show that the fluid shear rate of each type of amplitude decomposition structure is greater than that of the square dot array structure, and the dense pore structure inside helps to realize the full contact of the pollutants in the wastewater to be treated and the reaction sites on the catalyst surface, thereby improving the mass transfer efficiency and reaction efficiency of the catalytic process.

[0093] Figure 3 b) of FIG. shows the relationship diagram of the calculated surface area and permeability of different structures, and the comprehensive surface area calculation and mass transfer result analysis show that each type of amplitude decomposition structure has significantly better surface area and permeability than the square dot array structure, and among them, the isotropic amplitude decomposition structure has the largest specific surface area and relatively better mass transfer performance, so the subsequent catalyst skeleton precursor printing selects the isotropic amplitude decomposition structure.

[0094] In the present application, the overall structure size of the bicontinuous amplitude decomposition structure is (2-20) mm x (2-20) mm x (2-20) mm, for example, it can be 3 mm x 3 mm x 3 mm, 4 mm x 4 mm x 4 mm, 5 mm x 5 mm x 5 mm, 6 mm x 6 mm x 6 mm, 7 mm x 7 mm x 7 mm, 8 mm x 8 mm x 8 mm, 10 mm x 10 mm x 10 mm, 12 mm x 12 mm x 12 mm, 15 mm x 15 mm x 15 mm, 18 mm x 18 mm x 18 mm, etc.

[0095] In the present application, the relative density of the bicontinuous amplitude decomposition structure is 20-80%, for example, it can be 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, etc.

[0096] In some specific embodiments of the present application, the overall structure size of the bicontinuous amplitude decomposition structure is 5 mm x 5 mm x 5 mm, and the relative density is 30%.

[0097] In the present application, the porosity of the alumina ceramic dot array catalyst skeleton is 20-80%, for example, it can be 30%, 41%, 55%, 60%, 70%, etc.

[0098] In the present application, the specific surface area of the alumina ceramic lattice catalyst framework is 10m 2 / g-200m 2 / g, for example, can be 20m 2 / g, 50m 2 / g, 78m 2 / g, 111.3m 2 / g, 150m 2 / g, 158.7m 2 / g, 170m 2 / g, etc.

[0099] In the present application, the compressive strength of the alumina ceramic lattice catalyst framework is 5MPa-300MPa, for example, can be 10.0MPa, 20.0MPa, 30.0MPa, 40.0MPa, 50.0MPa, 70.0MPa, 100.0MPa, 150.0MPa, 200.0MPa, 250.0MPa, 280.0MPa, etc.

[0100] In the present application, the surface projection microstereolithography technology is a surface projection light curing digital light processing (DLP) technology.

[0101] In the present application, the thickness of the slice is 10-30μm, for example, can be 15μm, 20μm, 25μm, etc.

[0102] In the present application, the exposure time of the structure layer is 2-6 seconds, for example, can be 3 seconds, 4 seconds, 5 seconds, etc.

[0103] In the present application, the exposure time of the sacrificial layer is 3-8 seconds, for example, can be 4 seconds, 5 seconds, 6 seconds, 6.5 seconds, 7 seconds, 7.5 seconds, etc.

[0104] In the present application, setting different exposure times of the sacrificial layer can enhance the adhesion of the sacrificial layer and the printing platform, prevent sticking, and facilitate the separation of the structure layer and the sacrificial layer.

[0105] In the present application, the wavelength of the ultraviolet light is 300-450nm, for example, can be 350nm, 400nm, 405nm, 420nm, etc.

[0106] In the present application, the light intensity of the ultraviolet light is 2-50mW / cm 2 , for example, can be 5mW / cm 2 , 8mW / cm 2 , 10mW / cm 2 , 12mW / cm 2 , 15mW / cm 2 , 18mW / cm 2 , 20mW / cm 2, 24 mW / cm 2 , 25 mW / cm 2 , 30 mW / cm 2 , 40 mW / cm 2 , etc.

[0107] In some specific embodiments of the present application, the alumina slurry uses the alumina ceramic slurry (material model CA-100A) produced by Shenzhen Mofang New Material Co., Ltd.

[0108] In the present application, the ultrasonic cleaning time is 5-60 min, for example, it can be 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, etc.

[0109] In the present application, the water flow flushing time is 30-120 min, for example, it can be 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, etc.

[0110] Step 2)

[0111] The bicontinuous amplitude-modulated decomposition structure alumina catalyst framework precursor obtained in step 1) is subjected to debinding sintering to obtain a bicontinuous amplitude-modulated decomposition structure alumina catalyst framework.

[0112] In the present application, the debinding sintering includes the following three stages:

[0113] The first stage is vacuum debinding, and the bicontinuous amplitude-modulated decomposition structure alumina catalyst framework precursor is debound, heat preserved, and naturally cooled to room temperature in a tube furnace under a vacuum environment to obtain catalyst framework precursor-I;

[0114] The second stage is air debinding, and the catalyst framework precursor-I is again debound at high temperature, heat preserved, and naturally cooled to room temperature in a muffle furnace under an air environment to obtain catalyst framework precursor-II;

[0115] The third stage is air sintering, and the catalyst framework precursor-II is again sintered at high temperature, heat preserved, and naturally cooled to room temperature in a muffle furnace under an air environment, and finally a high-strength bicontinuous amplitude-modulated decomposition structure alumina catalyst framework can be obtained.

[0116] In some embodiments of the present application, in stage one, the temperature of the debinding is 400-800°C, for example, it can be 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, etc.

[0117] In some embodiments of the present application, in stage one, the temperature of the debinding is 400-800°C, for example, it can be 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, etc.

[0118] In some embodiments of the present application, in stage one, the temperature of the debinding is 400-800°C, for example, it can be 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, etc.

[0119] In some embodiments of the present application, in stage two, the temperature of the debinding is 800-1200°C, for example, it can be 850°C, 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1150°C, etc.

[0120] In some embodiments of the present application, in stage two, the temperature of the debinding is 800-1200°C, for example, it can be 850°C, 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1150°C, etc.

[0121] In some embodiments of the present application, in stage two, the temperature of the debinding is 800-1200°C, for example, it can be 850°C, 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1150°C, etc.

[0122] In some embodiments of the present application, in stage three, the temperature of the debinding is 800-1200°C, for example, it can be 850°C, 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1150°C, etc.

[0123] In some embodiments of the present application, in stage three, the temperature for defatting is 1400-1800℃, for example, it can be 1450℃, 1500℃, 1550℃, 1600℃, 1650℃, 1700℃, 1750℃, etc.

[0124] In some embodiments of the present application, in stage three, the time for holding is 40-120min, for example, it can be 50min, 60min, 70min, 80min, 90min, 100min, 110min, etc.

[0125] Step 3)

[0126] An impregnation solution containing a metal salt for forming a metal monatomic, a zinc salt and 2-methylimidazole is prepared, and a bicontinuous modulated decomposition structure alumina catalyst skeleton is put into the impregnation solution, ultrasonic impregnation, standing, filtration, to obtain a bicontinuous modulated decomposition structure alumina catalyst precursor loaded with metal monatomic.

[0127] In some embodiments of the present application, the metal salt and the zinc salt can be dissolved in a solvent to obtain solution A, 2-methylimidazole is dissolved in a solvent to obtain solution B, and solution B is added to solution A to obtain the impregnation solution. Alternatively, solutions A and B can be separately placed in an ultrasonic reactor for ultrasonic dissolution for 3-5min, and then mixed to obtain the impregnation solution.

[0128] In the present application, the molar ratio of the metal salt, the zinc salt and 2-methylimidazole is (0.1-10mmol):(1-20mmol):(10-120mmol), for example, it can be 2mmol:10mmol:40mmol.

[0129] In the present application, the metal salt is an acetylacetone salt of manganese, iron, nickel or cobalt. For example, it can be acetylacetone manganese.

[0130] In the present application, the zinc salt is selected from one or more of zinc acetate, zinc nitrate, zinc chloride, zinc sulfate and zinc carbonate. For example, it can be zinc nitrate.

[0131] In the present application, the solvent is C 1-6 An alcohol solution, for example, it can be methanol, ethanol, isopropanol, etc. The solvent used in solution A and solution B can be the same or different, and preferably the same solvent is used.

[0132] In some embodiments of the present application, ultrasonic impregnation is carried out in an ultrasonic reactor, and the time for ultrasonic impregnation is 10-120min, for example, it can be 20min, 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min, etc.

[0133] In some embodiments of the present application, the standing time is 12-96 hours, for example, it can be 20 hours, 24 hours, 30 hours, 36 hours, 40 hours, 42 hours, 48 hours, 50 hours, 54 hours, 60 hours, 66 hours, 70 hours, 72 hours, 80 hours, 84 hours, 90 hours, etc.

[0134] Step 4)

[0135] The metal monatomic supported bicontinuous modulated amplitude splitting structure alumina catalyst precursor is subjected to a post-treatment process to obtain a metal monatomic supported bicontinuous modulated amplitude splitting structure alumina catalyst.

[0136] In the present application, the post-treatment process includes drying, oxygen-free calcination, heat preservation, and natural cooling to room temperature.

[0137] In some embodiments of the present application, the drying is performed in an oven, and the drying temperature is 40-80℃, for example, it can be 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, etc. The drying time is 10-60 min, for example, it can be 15 min, 20 min, 25 min, 30 min, 40 min, 50 min, etc.

[0138] In some embodiments of the present application, the oxygen-free calcination is performed in a tube furnace under an argon atmosphere.

[0139] In the present application, the heating rate of the calcination is 1-5℃ / min, for example, it can be 1.5℃ / min, 2.0℃ / min, 2.5℃ / min, 3.0℃ / min, 3.5℃ / min, 4.0℃ / min, 4.5℃ / min, etc.

[0140] In the present application, the calcination temperature is 800-1200℃, for example, it can be 850℃, 900℃, 950℃, 1000℃, 1050℃, 1100℃, 1150℃, etc.

[0141] In the present application, the heat preservation time is 1-5 hours, for example, it can be 1.5 hours, 2.0 hours, 2.5 hours, 3.0 hours, 3.5 hours, 4.0 hours, 4.5 hours, etc.

[0142] The present application also provides an application of the metal monatomic supported bicontinuous modulated amplitude splitting structure alumina catalyst according to the foregoing or obtained by the foregoing preparation method in sewage treatment, preferably in ozone catalytic oxidation water treatment.

[0143] Example

[0144] The embodiments of the present application will be described in detail below with examples, but those skilled in the art will understand that the following examples are only for illustration of the present application and should not be regarded as limiting the scope of the present application. The specific conditions not specified in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not specified by the manufacturer, which are all conventional products that can be obtained by purchase.

[0145] Example 1: Preparation of an alumina catalyst with a single-atom manganese-loaded isotropic amplitude-splitting structure

[0146] (1) An isotropic amplitude-splitting structure was generated using the Gaussian random field method, wherein the relative density of the isotropic amplitude-splitting structure was 30%, and the overall structure size was 5 mm x 5 mm x 5 mm. An alumina slurry (commercially available, manufacturer: Shenzhen Mofang New Material Co., Ltd., model: CA-100A) was poured into the liquid tank of a face projection microstereolithography 3D printer, and the stl model file of the above structure was imported into the computer connected to the face projection microstereolithography 3D printer and sliced. The slice layer thickness was set to 20 μm, the ultraviolet light wavelength was 405 nm, the sacrificial layer exposure time was 3-8 seconds, the ultraviolet light intensity was 15 mW / cm 2 ; the structure layer exposure time was 4 seconds, and the ultraviolet light intensity was 10 mW / cm 2 . The alumina ceramic model (containing alumina catalyst skeleton precursor and sacrificial layer) was obtained by layer-by-layer solidification using face projection microstereolithography technology. The printed alumina ceramic model was peeled off from the printer platform with a blade, and the sacrificial layer was peeled off. The peeled alumina ceramic model was ultrasonically cleaned for 15 min and water-flushed for 60 min to remove residual slurry inside the structure. After cleaning, it was naturally dried on the dust-free paper for 24 h to obtain an alumina catalyst skeleton precursor with an isotropic amplitude-splitting structure.

[0147] (2) The alumina catalyst skeleton precursor with an isotropic amplitude-splitting structure obtained in step (1) was subjected to three-stage debinding and sintering, Figure 4 The temperature control curve for debinding and sintering of the alumina catalyst skeleton precursor with an isotropic amplitude-splitting structure is shown.

[0148] Stage one was vacuum debinding. The alumina catalyst skeleton precursor with an isotropic amplitude-splitting structure was debound in a tube furnace under vacuum environment, heated to 600°C at 1.6°C / min, and kept for 180 min. After natural cooling to room temperature, catalyst skeleton precursor-I was obtained.

[0149] Stage two is air degreasing, the catalyst skeleton precursor-I is transferred into a muffle furnace under air environment for high temperature degreasing again, heated to 200°C at 1.75°C / min, heated to 600°C at 1°C / min, kept for 180 min, heated to 1000°C at 4°C / min, kept for 30 min, then naturally cooled to room temperature, to obtain catalyst skeleton precursor-II.

[0150] Stage three is air sintering, the catalyst skeleton precursor-II is sintered again in a muffle furnace under air environment, heated to 1650°C at 5°C / min, kept for 60 min, then cooled to 1200°C at 5°C / min, and then naturally cooled to room temperature, to obtain high-strength isotropic amplitude modulation structure alumina catalyst skeleton, with a porosity of 70% and a specific surface area of about 170 m 2 / g.

[0151] (3) 2 mmol of acetylacetone manganese and 10 mmol of zinc nitrate hexahydrate solid powder were weighed and dissolved in 30 mL of methanol to obtain solution A; 40 mmol of 2-methylimidazole was weighed and dissolved in 30 mL of methanol to obtain solution B. Solution A and B were respectively placed in an ultrasonic reactor and dissolved under ultrasonic waves at 30 Hz for 3 min. The dissolved solution B was quickly poured into solution A to obtain an impregnation solution. 3 g of the isotropic amplitude modulation structure alumina catalyst skeleton was weighed and added into the impregnation solution, ultrasonic impregnated for 90 min at 30 Hz, and then statically placed for 72 hours, filtered, to obtain a metal monatomic loaded isotropic amplitude modulation structure alumina catalyst precursor.

[0152] (4) The metal monatomic loaded isotropic amplitude modulation structure alumina catalyst precursor was placed in a 60-degree oven for drying for 30 min, and then placed in a tube furnace for anaerobic calcination under argon atmosphere, heated to 900°C at a rate of 5°C / min, kept for 3 hours, then naturally cooled and taken out, to obtain a manganese monatomic loaded isotropic amplitude modulation structure alumina catalyst (manganese monatomic@amplitude modulation structure).

[0153] Comparative Example 1

[0154] The same preparation method as in Example 1 was adopted, the isotropic amplitude modulation structure in step (1) was changed to a cubic dot array structure, and the remaining operations were unchanged, to obtain a manganese monatomic loaded cubic dot array structure alumina catalyst (manganese monatomic@cubic dot array).

[0155] Comparative Example 2

[0156] The synthesis method of the manganese nanocluster loaded isotropic amplitude modulation structure alumina catalyst is as follows:

[0157] The same preparation method as in Example 1 was adopted, and the amount of acetylacetone manganese added in step (3) was changed to 6 mmol, and the remaining operations were unchanged, to obtain a manganese nanocluster-loaded isotropic amplitude modulation decomposition structure alumina catalyst (manganese nanocluster@amplitude modulation structure).

[0158] Comparative Example 3

[0159] The synthesis method of the manganese monatomic-loaded alumina spherical catalyst is as follows:

[0160] 2 mmol of acetylacetone manganese and 10 mmol of solid zinc nitrate hexahydrate were weighed and dissolved in 30 mL of methanol to obtain solution A; 40 mmol of 2-methylimidazole was dissolved in 30 mL of methanol to obtain solution B. Solutions A and B were placed in an ultrasonic reactor respectively, and were ultrasonically dissolved at 30 Hz for 5 min. The dissolved solution B was quickly poured into solution A to obtain an impregnation solution. 5 g of alumina ceramic beads (type A820850, particle size 3-5 mm, purchased from Shanghai Macklin Biotech Co., Ltd.) were weighed and added to the impregnation solution, and were ultrasonically impregnated at 30 Hz for 60 min, then were left to stand for 72 hours, were filtered, and a manganese monatomic-loaded alumina spherical catalyst precursor was obtained. The manganese monatomic-loaded alumina spherical catalyst precursor was then placed in a 60-degree oven and dried for 30 min, and was then placed in a tube furnace and subjected to anaerobic calcination under an argon atmosphere, and was heated to 900°C at a rate of 5°C / min, and was kept at this temperature for 3 hours, and was then taken out after natural cooling, to obtain a manganese monatomic-loaded alumina spherical catalyst (manganese monatomic@spherical structure).

[0161] Alumina catalyst framework precursor

[0162] Figure 5 The actual photos of the isotropic amplitude modulation decomposition structure alumina catalyst skeleton precursor, the square dot catalyst skeleton precursor and the alumina ceramic beads obtained in Example 1 and Comparative Examples 1 and 3 are shown in a) of FIG. 1.

[0163] Manganese monatomic supported alumina catalyst

[0164] Figure 5 The actual photos of the manganese monatomic-loaded alumina catalyst prepared in Example 1 and Comparative Examples 1 and 3 are shown in b) of FIG. 1.

[0165] Uniaxial compression experiment

[0166] The isotropic amplitude modulation decomposition structure alumina catalyst skeleton (precursor) sample after 3D printing, vacuum debinding and sintering treatment in Example 1 was subjected to uniaxial compression experiment, and the results are shown in FIG. 2. Figure 6 From the stress-strain curve in the figure, it can be seen that the compression strain rate is 10-3 s -1 After the defatting sintering treatment, the compressive strength of the alumina catalyst framework of the isotropic amplitude modulation decomposition structure is 10.55 MPa, which is increased to 10.7 times of the structure after printing (the compressive strength is 0.99 MPa), and the fracture strain is 19.9%, indicating that the post-treatment of defatting sintering significantly improves the strength and toughness of the catalyst framework.

[0167] Scanning electron microscope (SEM) test

[0168] The catalyst prepared in Example 1 was subjected to microscopic performance analysis, and the results are shown in Figure 7 It can be seen from Figure 7 that it has a micropore structure.

[0169] X-ray diffraction (XRD) test

[0170] The surface active site characteristics of the catalyst prepared in Example 1 (manganese monatomic catalyst), the catalyst prepared in Comparative Example 2 (manganese nanocluster catalyst) and the nanocarbon catalyst were tested, and the results are shown in Figure 8 a) and b) of FIG. 8. Figure 8 The XRD data of the samples under different loading conditions are shown in a) of FIG. 8, and it can be seen from the figure that the manganese monatomic catalyst does not have obvious crystal diffraction peaks, which is consistent with the diffraction peaks of the pure nanocarbon catalyst; while the manganese nanocluster catalyst has obvious MnO diffraction peaks, further proving the existence of oxide clusters therein. Figure 8 The data results of the manganese monatomic catalyst synchrotron R-space fitting are shown in b) of FIG. 8, and it can be concluded from the fitting data analysis that Mn mainly exists in Mn-N, Mn-C and Mn-N1 coordination structures, and the number of Mn-N coordination in the first layer is 4, indicating that it is a planar 4-coordination structure; while the outer layer has Mn-C and Mn-N1, which is consistent with the structure of MnPc (phthalocyanine manganese), indicating that Mn exists in the form of monatomic.

[0171] The synthesis method of the pure nanocarbon catalyst is as follows:

[0172] Take 10 mmol of zinc nitrate hexahydrate solid powder and dissolve it in 30 mL of methanol to obtain solution A; take 40 mmol of 2-methylimidazole and dissolve it in 30 mL of methanol to obtain solution B. Place solutions A and B in an ultrasonic reactor respectively, and ultrasonically dissolve solution B for 5 min at 30 Hz. Pour the dissolved solution B into solution A quickly to obtain a mixture. Ultrasonically immerse the mixture for 60 min at 30 Hz, then let it stand for 72 hours, filter to obtain a nano-carbon catalyst precursor. Then place the nano-carbon catalyst precursor in a 60-degree oven to dry for 30 min, and then place it in a tube furnace under an argon atmosphere for anaerobic calcination. Increase the temperature to 900°C at a rate of 5°C / min, and then keep the temperature for 3 hours. Then take it out after natural cooling, to obtain a pure nano-carbon catalyst.

[0173] Example 2: Application of manganese-loaded alumina catalyst in simulated wastewater treatment

[0174] (1) Take oxalic acid as a typical pollutant as a model pollutant, and use the method of ozone catalytic oxidation to degrade and treat it. Use a 1L volumetric flask to prepare a 100mg / L oxalic acid solution. Take out 200mL as simulated wastewater to be degraded each time for cyclic reaction.

[0175] Build a cyclic reaction device as shown in Figure 9 , to carry out ozone catalytic oxidation wastewater treatment. During the reaction, the simulated wastewater is placed in a beaker, and oxygen is converted into ozone by an ozone generator and introduced into the simulated wastewater. The introduced ozone is combined with the pollutant wastewater solution through the aeration head, and the solution mixed with ozone is pumped into the acrylic reactor (the lower port is the solution inlet, and the upper port is the solution outlet) through a peristaltic pump, and is in contact with the catalyst filled in the acrylic chamber for degradation and reaction, and finally returns to the beaker to form a cyclic reaction.

[0176] Fill the catalyst prepared in Example 1 in the acrylic chamber, and the gas flow rate during the reaction is 0.2L / min, the ozone concentration of the system is 8mg / L, and the degradation time is 60min.

[0177] (2) At 0, 2, 5, 10, 20, 30, 45, and 60 min of the reaction, use a 2.5mL syringe to take 0.5mL of water sample, filter it through a 45-micron filter membrane, and then inject it into a chromatographic bottle. Wait for subsequent testing.

[0178] (3) Use a high-performance liquid chromatograph (brand: Agilent, model: 1260Infinity II) to analyze the water sample, and use an ultraviolet detector (wavelength 210nm) as the detector, and use 20mM sodium dihydrogen phosphate buffer as the mobile phase. Analyze and arrange the concentration data, draw a degradation curve graph for 60min, and perform fitting analysis on the reaction kinetics results to calculate the kinetic constant.

[0179] The catalysts prepared in Example 1 were replaced with the manganese single-atom supported alumina block lattice catalyst prepared in Comparative Example 1, the manganese nanocluster supported isotropic amplitude-modulated decomposition structure alumina catalyst prepared in Comparative Example 2, and the manganese single-atom supported alumina spherical catalyst prepared in Comparative Example 3, as well as without catalysts. The tests were conducted using the same apparatus and test conditions as described above.

[0180] Results

[0181] Figure 10 The results in a) and b) indicate that the catalyst prepared in Example 1 exhibits the best degradation effect, achieving a pollutant removal rate of over 90% within 60 minutes and a degradation rate as high as 0.0447 min. -1 The manganese single-atom supported alumina block lattice catalyst prepared in Comparative Example 1 showed the second best degradation rate, at 0.0311 min. -1 The isotropic amplitude-modulated decomposition structure alumina catalyst supported by manganese nanoclusters prepared in Comparative Example 2 and the spherical alumina catalyst supported by manganese single atoms prepared in Comparative Example 3 showed poor degradation effects, with degradation rates of 0.0254 min, respectively. -1 and 0.0264min -1 Pure ozone systems without catalysts show almost no degradation.

[0182] Example 3: Investigating the reactive oxygen species generated during ozone catalytic oxidation of wastewater

[0183] exist Figure 9 The acrylic reactor chamber was filled with the catalyst prepared in Example 1. Using the same apparatus and steps as in Example 2, 15 mM tert-butanol (TBA), methanol (MeOH), and potassium phosphate (K3PO4) were added as quenching agents to conduct quenching experiments. The concentration data were analyzed and compiled, a degradation curve of 60 min was plotted, and the oxalic acid removal rate constant was calculated.

[0184] TBA can quench hydroxyl radicals in solution; MeOH can quench hydroxyl radicals on the catalyst surface in solution; K3PO4 can quench Lewis acid sites on the catalyst surface.

[0185] Results

[0186] Figure 11The results of a) and b) show that the active oxygen species produced in the process of catalytic ozonation of wastewater by the manganese monatomic supported isotropic amplitude death structure alumina catalyst is mainly hydroxyl radical. When the quenching agent TBA and MeOH are added, the overall degradation rate of the system is significantly slower, and the rate of slowing down is more obvious when MeOH is added. Further when K3PO4 is added, the degradation of the system is almost inhibited. It can be basically inferred that the active oxygen radical produced in the system is on the Lewis acid site on the surface of the prepared catalyst, and the form of production is mainly hydroxyl radical.

[0187] It should be noted that although the technical solutions of the present application are described with specific examples, those skilled in the art can understand that the present application should not be limited thereto.

[0188] The above has described various embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical application or improvement of technology in the market, or to enable other ordinary skilled in the art to understand the embodiments disclosed herein.

Claims

1. A metal monatomic supported biomimetic bicontinuous amplitude modulated decomposition structure alumina catalyst characterized in that, comprise: an alumina catalyst skeleton having a bicontinuous amplitude splitting structure; and metallic single atoms supported on the alumina catalyst skeleton; wherein the metallic single atoms are selected from one or more of manganese, iron, nickel, and cobalt; the bicontinuous amplitude splitting structure is an isotropic amplitude splitting structure; a method for preparing the metallic single atom supported bicontinuous amplitude splitting structure alumina catalyst comprises the following steps: (1) obtaining a bicontinuous amplitude splitting structure alumina catalyst skeleton precursor by 3D printing through a face projection microstereolithography technique; (2) performing debinding sintering on the bicontinuous amplitude splitting structure alumina catalyst skeleton precursor to obtain a bicontinuous amplitude splitting structure alumina catalyst skeleton; (3) preparing an impregnation solution containing a metal salt for forming the metallic single atoms, a zinc salt, and 2-methylimidazole, placing the bicontinuous amplitude splitting structure alumina catalyst skeleton in the impregnation solution, and performing ultrasonic impregnation, standing, and filtration to obtain a metallic single atom supported bicontinuous amplitude splitting structure alumina catalyst precursor; (4) performing a post-treatment process on the metallic single atom supported bicontinuous amplitude splitting structure alumina catalyst precursor to obtain the metallic single atom supported bicontinuous amplitude splitting structure alumina catalyst.

2. The catalyst according to claim 1, wherein a loading amount of the metallic single atoms is 0.03-5 wt%.

3. The catalyst according to claim 1 or 2, wherein an overall structure size of the bicontinuous amplitude splitting structure is (2-20) mm x (2-20) mm x (2-20) mm; and a relative density of the bicontinuous amplitude splitting structure is 20-80%.

4. The catalyst according to claim 1 or 2, wherein a porosity of the alumina catalyst skeleton is 20-80%; and a compressive strength of the alumina catalyst skeleton is 5 MPa-300 MPa. The specific surface area of the alumina catalyst skeleton is 10 m 2 / g - 200 m 2 / g; comprise the following steps:

5. The process for the preparation of a catalyst according to any one of claims 1-4, characterized in that, (1) obtaining a bicontinuous amplitude splitting structure alumina catalyst skeleton precursor by 3D printing through a face projection microstereolithography technique; (2) performing debinding sintering on the bicontinuous amplitude splitting structure alumina catalyst skeleton precursor to obtain a bicontinuous amplitude splitting structure alumina catalyst skeleton; (3) preparing an impregnation solution containing a metal salt for forming the metallic single atoms, a zinc salt, and 2-methylimidazole, placing the bicontinuous amplitude splitting structure alumina catalyst skeleton in the impregnation solution, and performing ultrasonic impregnation, standing, and filtration to obtain a metallic single atom supported bicontinuous amplitude splitting structure alumina catalyst precursor; (4) performing a post-treatment process on the metallic single atom supported bicontinuous amplitude splitting structure alumina catalyst precursor to obtain the metallic single atom supported bicontinuous amplitude splitting structure alumina catalyst. in step (1), 6. The production method according to claim 5, wherein ​ Determine a three-dimensional geometric model file with a bicontinuous amplitude modulation decomposition structure in a three-dimensional design software; pour an alumina slurry into a liquid tank of a 3D printer, import the three-dimensional geometric model file into a computer connected to the 3D printer for slicing, and then perform 3D printing by layer-by-layer curing under ultraviolet light; Wherein, the layer thickness of the slice is 10-30 μm; the exposure time of each layer is 2-10 seconds; The wavelength of the ultraviolet light is 300 to 405 nm; the light intensity of the ultraviolet light is 2~50 mW / cm 2 .

7. The production method according to claim 5 or 6, characterized by, In step (2), the debinding and sintering includes the following three stages: Stage one: debinding, holding, and cooling to room temperature of the alumina catalyst framework precursor of the bicontinuous amplitude modulation decomposition structure, to obtain catalyst framework precursor-I; Wherein, stage one is carried out in a vacuum environment, the debinding temperature increasing rate is 0.5-5 ℃ / min; the debinding temperature is 400-800 ℃; the holding time is 160-220 min; Stage two: debinding, holding, and cooling to room temperature of the catalyst framework precursor-I, to obtain catalyst framework precursor-II; Wherein, stage two is carried out in an air environment, the debinding temperature increasing rate is 0.5-5 ℃ / min, the debinding temperature is 800-1200 ℃, and the holding time is 20-80 min; Stage three: sintering, holding, and cooling to room temperature of the catalyst framework precursor-II, to obtain the alumina catalyst framework of the bicontinuous amplitude modulation decomposition structure; Wherein, stage three is carried out in an air environment, the sintering temperature increasing rate is 2-8 ℃ / min, the sintering temperature is 1400-1800 ℃, and the holding time is 40-120 min.

8. The production method according to claim 5 or 6, characterized by, In step (3), The molar ratio of the metal salt, zinc salt, and 2-methylimidazole is (0.1-10 mmol):(1-20 mmol):(10-120 mmol); Wherein, the metal salt is an acetylacetone salt of manganese, iron, nickel, or cobalt; the zinc salt is selected from one or more of zinc acetate, zinc nitrate, zinc chloride, zinc sulfate, and zinc carbonate; The ultrasonic immersion time is 10-120 min; and the standing time is 12-96 hours.

9. The production method according to claim 5 or 6, characterized by, In step (4), the post-treatment process includes drying, oxygen-free roasting, holding, and cooling to room temperature; Wherein, The drying temperature is 40-80 ℃; and the drying time is 10-60 min; The roasting temperature increasing rate is 1-5 ℃ / min; the roasting temperature is 800-1200 ℃; and the holding time is 1-5 hours.

10. The application of the metal monatomic loaded bionic bicontinuous amplitude modulation decomposition structure alumina catalyst according to any one of claims 1-4 or obtained by the preparation method of any one of claims 5-9 in sewage treatment.

11. The application of the metal monatomic loaded bionic bicontinuous amplitude modulation decomposition structure alumina catalyst according to any one of claims 1-4 or obtained by the preparation method of any one of claims 5-9 in ozone catalytic oxidation water treatment.

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