A crystal plane-regulated supported manganese tantalate catalyst and preparation method thereof

Abstract

The present application provides a supported manganese tantalate catalyst with controlled crystal faces and a preparation method thereof, relating to the field of catalytic materials. The supported manganese tantalate catalyst comprises manganese tantalate and an activated alumina support, wherein the structure of the manganese tantalate comprises at least one of an octahedral structure, a nano-platelet sphere structure, and a nano-flowered sphere structure. The supported manganese tantalate catalyst provided herein can expose supported manganese tantalate with specific highly active crystal faces, so that the manganese tantalate phase is uniformly distributed on the surface of the activated alumina sphere support in the form of nano-scale octahedra, platelets, and flowers, thereby increasing the number and availability of active sites and accelerating electron transfer at the solid-liquid interface, significantly improving the activation efficiency of persulfate.

Description

Technical Field

[0001] The present application relates to the field of catalytic materials, and in particular to a crystal plane-controlled supported manganese tantalate catalyst and a preparation method thereof. Background Art

[0002] Persulfate oxidation technology is a widely used method in the field of advanced oxidation. Its core active species is sulfate radical (SO4 - ) possesses extremely strong oxidizing power, enabling efficient mineralization of organic pollutants. However, in actual mineral processing wastewater, sulfate radicals are susceptible to interference from background substances (such as inorganic anions and dissolved organic matter), leading to increased persulfate dosage and reduced oxidation efficiency, thus limiting the industrial application of persulfate oxidation technology. Therefore, developing efficient and environmentally friendly persulfate non-radical oxidation technology and catalysts under practical conditions has become an important development direction in this field.

[0003] Manganese is abundant and readily available, and manganese-based oxides have become a research hotspot for wastewater treatment materials due to their excellent catalytic properties. Tantalate compounds, as typical representatives of pyrochlore structures, are characterized by their regular structure, ease of regulation, and diverse composition. However, there have been no reports of pyrochlore compounds acting as persulfate catalysts. Combining the two to create manganese tantalate nanomaterials could fully leverage their synergistic advantages, potentially leading to the development of highly efficient persulfate catalysts and providing new insights and approaches to addressing these technical bottlenecks. Summary of the Invention

[0004] The purpose of this application is to provide a supported manganese tantalate catalyst with controlled crystal surface and a preparation method thereof to solve the above problems.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] The present application provides a supported manganese tantalate catalyst with controlled crystal planes, wherein the supported manganese tantalate catalyst comprises manganese tantalate and an activated alumina carrier, wherein the manganese tantalate is supported on the activated alumina carrier; the structure of the manganese tantalate comprises at least one of an octahedral structure, a nanosheet ball structure, and a nanoflower ball structure.

[0007] Optionally, the manganese tantalate crystal exposes at least one of the crystal planes (621), (211), and (200).

[0008] The present application also provides a method for preparing a supported manganese tantalate catalyst with controlled crystal plane, the method comprising:

[0009] First mixing water and glycerol to prepare a mixed solution;

[0010] performing a second mixing of the mixed solution with a manganese salt, an amino acid, a chlorine-containing pyridine compound, and activated alumina to obtain a reaction precursor;

[0011] The reaction precursor and tantalum pentoxide are mixed for a third time and then heat treated to obtain the manganese tantalate.

[0012] Optionally, the volume ratio of the water to the glycerol is 1:0.5-1.

[0013] Optionally, the manganese salt includes at least one of manganese chloride, manganese sulfate, and manganese acetate.

[0014] Optionally, the amino acids include alanine family amino acids.

[0015] Optionally, the activated alumina includes activated alumina balls.

[0016] Optionally, the alanine family amino acids include at least one of L-2-chlorophenylalanine, L-4-fluorophenylalanine, and ZL-alanine.

[0017] Optionally, the chlorine-containing pyridine compound includes at least one of 6-chloro-2-hydroxymethylpyridine, dodecylpyridinium chloride, and 2-chloro-3-hydroxypyridine.

[0018] Optionally, the usage ratio of the manganese salt, the amino acid, the chlorine-containing pyridine compound and the activated alumina is 0.5-1.0 mmol: 0.2-0.4 g: 0.1-0.2 g: 0.3-0.5 g.

[0019] Optionally, the ratio of the mixed solution to the tantalum pentoxide is 15 mL: 1-2 mmol.

[0020] Optionally, the heat treatment is carried out under closed conditions, the temperature of the heat treatment is 100-140° C., and the time is 4-8 hours.

[0021] Compared with the prior art, the advantages of this application include:

[0022] The supported manganese tantalate catalyst provided in the present application is capable of exposing supported manganese tantalate with specific highly active crystal faces, so that the manganese tantalate phase is evenly distributed on the surface of the activated alumina sphere support in the morphology of nano-scale octahedrons, flake balls and flower balls, which not only increases the number and availability of active sites, but also accelerates electron transfer at the solid-liquid interface, significantly improving the activation efficiency of persulfate.

[0023] The preparation method provided in the present application can, on the one hand, finely control manganese tantalate through liquid-phase controllable synthesis; on the other hand, the synthesis process is simple, easy to operate, and the synthesis process is stable, which can achieve highly consistent repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0025] Figure 1 This is a scanning electron microscope image of the supported manganese tantalate catalyst with crystal plane control provided in Example 1;

[0026] Figure 2 This is a scanning electron microscope image of the supported manganese tantalate catalyst with crystal plane regulation provided in Example 2;

[0027] Figure 3 This is a scanning electron microscope image of the supported manganese tantalate catalyst with crystal plane control provided in Example 3;

[0028] Figure 4 The XRD spectra of the manganese tantalate prepared in Examples 1, 2, and 3 are shown;

[0029] Figure 5 is the XRD spectrum of manganese tantalate prepared in Comparative Example 1;

[0030] Figure 6 The XRD spectra of manganese tantalate prepared in Comparative Examples 2, 3, and 4 are shown;

[0031] Figure 7 This is the performance curve of manganese tantalate used to activate sodium persulfate to oxidize COD. DETAILED DESCRIPTION

[0032] As used herein:

[0033] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0034] The conjunction "consisting of" excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed, excluding materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim, rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0035] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed alone. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including the range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0036] In these examples, parts and percentages are by mass unless otherwise indicated.

[0037] "Parts by mass" refers to the basic unit of measurement used to express the mass ratio of multiple components. One part can represent any unit of mass, such as 1g or 2.689g. For example, if we say that the parts by mass of component A are a parts and the parts by mass of component B are b parts, this means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, we could say that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number representing a multiplication factor). It's important to note that, unlike parts by mass, the sum of the parts by mass of all components is not limited to 100 parts.

[0038] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0039] In order to better explain the technical solution provided by this application, the technical solution will be explained as a whole before the embodiments.

[0040] In a first aspect, the present application provides a supported manganese tantalate catalyst with controlled crystal planes, wherein the supported manganese tantalate catalyst comprises manganese tantalate and an activated alumina carrier, wherein the manganese tantalate is supported on the activated alumina carrier; the structure of the manganese tantalate comprises at least one of an octahedral structure, a nanosheet ball structure, and a nanoflower ball structure.

[0041] In an optional embodiment, the manganese tantalate crystal exposes at least one of the crystal planes (621), (211), and (200).

[0042] In a second aspect, the present application further provides a method for preparing a supported manganese tantalate catalyst with controlled crystal planes, the method comprising:

[0043] First mixing water and glycerol to prepare a mixed solution;

[0044] performing a second mixing of the mixed solution with a manganese salt, an amino acid, a chlorine-containing pyridine compound, and activated alumina to obtain a reaction precursor;

[0045] The reaction precursor and tantalum pentoxide are mixed for a third time and then heat treated to obtain the manganese tantalate.

[0046] In an optional embodiment, the volume ratio of the water to the glycerol is 1:0.5-1.

[0047] Optionally, the volume ratio of the water to the glycerol can be 1:0.5, 1:0.55, 1:0.6, 1:0.65, 1:0.7, 1:0.75, 1:0.8, 1:0.85, 1:0.9, 1:0.95, 1:1, or any value between 1:0.5 and 1.

[0048] In an optional embodiment, the manganese salt includes at least one of manganese chloride, manganese sulfate, and manganese acetate.

[0049] In an alternative embodiment, the amino acids include alanine family amino acids.

[0050] In an optional embodiment, the activated alumina includes activated alumina balls.

[0051] In an optional embodiment, the alanine family amino acids include at least one of L-2-chlorophenylalanine, L-4-fluorophenylalanine, and ZL-alanine.

[0052] In an optional embodiment, the chlorine-containing pyridine compound includes at least one of 6-chloro-2-hydroxymethylpyridine, dodecylpyridinium chloride, and 2-chloro-3-hydroxypyridine.

[0053] In an optional embodiment, the usage ratio of the manganese salt, the amino acid, the chlorine-containing pyridine compound and the activated alumina is 0.5-1.0 mmol: 0.2-0.4 g: 0.1-0.2 g: 0.3-0.5 g.

[0054] Optionally, the amount of the manganese salt, the amino acid, the chlorine-containing pyridine compound and the activated alumina can be in a relationship of 0.5mmol:0.2g:0.1g:0.3g, 0.6mmol:0.2g:0.1g:0.3g, 0.7mmol:0.2g:0.1g:0.3g, 0.8mmol:0.2g:0.1g:0.3g, 0.9mmol:0.2g:0.1g:0.3g, 1.0mmol:0.2g:0.1g:0.3g, 0.5mmol:0.3g:0.1g:0.3g, 0.5mmol:0.4g:0.1g:0.3g, 0.5mmol:0.2g:0.2g:0.3g, 0. 5mmol: 0.2g: 0.1g: 0.4g, 0.5mmol: 0.2g: 0.1g: 0.5g, 0.6mmol: 0.3g: 0.2g: 0.4g, 0.7mmol: 0.3g: 0.2g: 0.4g, 0.8mmol: 0.3g: 0.2g: 0.4g, 0.9mmol: 0.3g: 2g: 0.4g, 1.0mmol: 0.3g: 0.2g: 0.4g, 1.0mmol: 0.3g: 0.2g: 0.5g, 1.0mmol: 0.4g: 0.2g: 0.5g, or any value between 0.5-1.0mmol: 0.2-0.4g: 0.1-0.2g: 0.3-0.5g.

[0055] In an optional embodiment, the ratio of the mixed solution to the tantalum pentoxide is 15 mL: 1-2 mmol.

[0056] Optionally, the dosage relationship of the mixed solution and the tantalum pentoxide can be 15 mL: 1 mmol, 15 mL: 1.2 mmol, 15 mL: 1.4 mmol, 15 mL: 1.6 mmol, 15 mL: 1.8 mmol, 15 mL: 2 mmol, or any value between 15 mL: 1-2 mmol.

[0057] In an optional embodiment, the heat treatment is carried out under closed conditions, the temperature of the heat treatment is 100-140° C., and the time is 4-8 hours.

[0058] Optionally, the heat treatment temperature may be 100° C., 115° C., 120° C., 125° C., 130° C., 135° C., 140° C., or any value between 100-140° C. The heat treatment time may be 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, or any value between 4-8 hours.

[0059] It is understandable that the present application is based on the theoretical basis of the rotational regulation of the geometric configuration of amino acids on metal coordination bonds and the electronic interaction between bridging metal ions, and has developed a simple and efficient preparation method. The present application uses alanine family amino acids and chlorine-containing pyridine solution as precursor raw materials, and achieves the directional arrangement of lattice atoms through solvent thermal synthesis technology, and accurately loads manganese tantalate with a specific morphology structure on an activated alumina support. This specific morphology of manganese tantalate can expose different highly active crystal faces, significantly increasing the number and availability of active sites, thereby greatly improving the activation efficiency of persulfate. Therefore, the crystal face-regulated supported manganese tantalate catalyst prepared in this application not only has high intrinsic activity and abundant active sites, but also exhibits excellent catalytic performance, providing an efficient and practical innovative solution for the field of persulfate activation treatment of mineral processing wastewater. On the one hand, this method can efficiently achieve the batch preparation of manganese tantalate with high intrinsic catalytic activity and abundant active sites; on the other hand, through the loading of activated alumina balls, not only the stability of manganese tantalate is significantly improved, but also it is easy to recycle. This innovation effectively solves the technical bottlenecks of low catalytic efficiency and difficult recovery that are common in existing persulfate nanocatalysts, giving it broad application prospects in mineral processing wastewater treatment and other catalytic materials.

[0060] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. The reagents or instruments used are not specified by the manufacturer and are conventional products that can be purchased commercially.

[0061] Example 1

[0062] This embodiment provides a supported manganese tantalate catalyst with controlled crystal plane.

[0063] Figure 1 This is a scanning electron microscope image of the supported manganese tantalate catalyst with crystal surface regulation; Figure 1 As shown, the structure of the supported manganese tantalate catalyst regulated by the crystal plane is an octahedral structure.

[0064] This embodiment also provides a method for preparing the supported manganese tantalate catalyst with controlled crystal planes, and the specific steps are as follows:

[0065] 10 mL of water and 5 mL of glycerol were mixed to obtain a mixed solution.

[0066] The mixed solution was mixed with MnCl2·4H2O, L-2-chlorophenylalanine, 6-chloro-2-hydroxymethylpyridine, and activated alumina balls to obtain a reaction precursor. The amounts of MnCl2·4H2O, L-2-chlorophenylalanine, 6-chloro-2-hydroxymethylpyridine, and activated alumina balls were 0.6 mmol: 0.25 g: 0.1 g: 0.3 g.

[0067] 1.2 mmol of tantalum pentoxide powder was added to 15 mL of the reaction precursor and heat-treated at 110° C. for 4 hours in a closed reactor to obtain a supported manganese tantalate catalyst with controlled crystal surface.

[0068] Example 2

[0069] This embodiment provides a supported manganese tantalate catalyst with controlled crystal surface:

[0070] Figure 2 This is a scanning electron microscope image of the supported manganese tantalate catalyst with crystal surface regulation; Figure 2 As shown, the structure of the supported manganese tantalate catalyst regulated by the crystal plane is a nanosheet sphere structure.

[0071] This embodiment also provides a method for preparing the supported manganese tantalate catalyst with controlled crystal planes, and the specific steps are as follows:

[0072] Mix 10 mL of water and 6 mL of propylene glycol to obtain a mixed solution.

[0073] The mixed solution is mixed with MnSO4·4H2O, L-2-chlorophenylalanine, dodecylpyridinium chloride, and activated alumina spheres to obtain a reaction precursor. The amounts of MnSO4·4H2O, L-2-chlorophenylalanine, dodecylpyridinium chloride, and activated alumina spheres are 0.7 mmol: 0.3 g: 0.1 g: 0.5 g.

[0074] 1.4 mmol of tantalum pentoxide powder was added to 16 mL of the reaction precursor and heat-treated at 120° C. for 7 hours in a closed reactor to obtain a supported manganese tantalate catalyst with controlled crystal surface.

[0075] Example 3

[0076] This embodiment provides a supported manganese tantalate catalyst with controlled crystal surface:

[0077] Figure 3 This is a scanning electron microscope image of the supported manganese tantalate catalyst with crystal surface regulation; Figure 3 As shown, the structure of the supported manganese tantalate catalyst regulated by the crystal plane is a nano-flower ball structure.

[0078] This embodiment also provides a method for preparing the supported manganese tantalate catalyst with controlled crystal planes, and the specific steps are as follows:

[0079] 7 mL of water and 7 mL of glycerol were mixed to obtain a mixed solution.

[0080] The mixed solution is mixed with (CH3COO)2Mn, ZL-alanine, 2-chloro-3-hydroxypyridine, and activated alumina spheres to obtain a reaction precursor. The amounts of (CH3COO)2Mn, ZL-alanine, 2-chloro-3-hydroxypyridine, and activated alumina spheres are 1 mmol: 0.25 g: 0.2 g: 0.4 g.

[0081] 1.4 mmol of tantalum pentoxide powder was added to 14 mL of the reaction precursor, and the mixture was heat treated at 140° C. for 8 hours in a closed reactor to obtain a supported manganese tantalate catalyst with controlled crystal surface.

[0082] Comparative Example 1

[0083] This comparative example provides a conventional method for preparing a manganese tantalate catalyst, and the specific steps are as follows:

[0084] Mix 0.3g of commercially available tantalum pentoxide powder with 1mL of hydrofluoric acid to form a suspension. Heat to 120°C until completely dissolved, resulting in a clear solution. After the solution cools to room temperature, slowly add aqueous ammonia (the same volume as the hydrofluoric acid) dropwise until the reaction is complete. A white precipitate forms, which is amorphous tantalum pentoxide.

[0085] Amorphous tantalum pentoxide, 0.4 g of MnCl2·4H2O, 15 mL of ethanol, and 0.4 g of activated alumina balls were mixed to obtain a reaction precursor.

[0086] The reaction precursor was heat-treated at 160° C. for 6 hours in a closed reactor to obtain a supported manganese tantalate catalyst.

[0087] Comparative Example 2

[0088] This comparative example provides a method for preparing a manganese tantalate catalyst, and the specific steps are as follows:

[0089] 10 mL of water and 5 mL of glycerol were mixed to obtain a mixed solution.

[0090] The mixed solution was mixed with MnCl2·4H2O, 2-mercapto-3-pyridinecarboxylic acid, 6-chloro-2-hydroxymethylpyridine, and activated alumina balls to obtain a reaction precursor. The amounts of MnCl2·4H2O, 2-mercapto-3-pyridinecarboxylic acid, 6-chloro-2-hydroxymethylpyridine, and activated alumina balls were 0.6 mmol: 0.25 g: 0.1 g: 0.3 g.

[0091] 1.2 mmol of tantalum pentoxide powder was added to 15 mL of the reaction precursor and heat-treated at 110° C. for 4 hours in a closed reactor to obtain a supported manganese tantalate catalyst with controlled crystal surface.

[0092] Comparative Example 3

[0093] This comparative example provides a method for preparing a manganese tantalate catalyst, and the specific steps are as follows:

[0094] 10 mL of water and 5 mL of glycerol were mixed to obtain a mixed solution.

[0095] The mixed solution is mixed with MnCl2·4H2O, DL-glutamic acid, 6-chloro-2-hydroxymethylpyridine, and activated alumina balls to obtain a reaction precursor. The amounts of MnCl2·4H2O, DL-glutamic acid, 6-chloro-2-hydroxymethylpyridine, and activated alumina balls are 0.6 mmol: 0.25 g: 0.1 g: 0.3 g.

[0096] 1.2 mmol of tantalum pentoxide powder was added to 15 mL of the reaction precursor and heat-treated at 110° C. for 4 hours in a closed reactor to obtain a supported manganese tantalate catalyst with controlled crystal surface.

[0097] Comparative Example 4

[0098] This comparative example provides a method for preparing a manganese tantalate catalyst, and the specific steps are as follows:

[0099] 10 mL of water and 5 mL of glycerol were mixed to obtain a mixed solution.

[0100] The mixed solution is mixed with MnCl2·4H2O, L-2-chlorophenylalanine, acetamide, and activated alumina balls to obtain a reaction precursor. The amounts of MnCl2·4H2O, L-2-chlorophenylalanine, acetamide, and activated alumina balls are 0.6 mmol: 0.25 g: 0.1 g: 0.3 g.

[0101] The XRD spectra of manganese tantalate prepared in Examples 1, 2 and 3 are as follows: Figure 4 As shown, the manganese tantalate crystal provided in Example 1 exposes the (621) crystal plane, the manganese tantalate crystal provided in Example 2 exposes the (211) crystal plane, and the manganese tantalate crystal provided in Example 3 exposes the (200) crystal plane. Figure 5 is the XRD spectrum of manganese tantalate prepared in Comparative Example 1, Figure 6 The XRD spectra of manganese tantalate prepared in Comparative Examples 2, 3 and 4 are shown in Table 1. Figure 5 、 Figure 6It can be seen that the manganese tantalate crystals prepared in Comparative Examples 1, 2, 3, and 4 exposed the (311) crystal plane, but did not expose any of the (621) crystal plane, (211) crystal plane, and (200) crystal plane; this indicates that the supported manganese tantalate catalyst prepared by the technical solution provided in the present application contains more reaction steps, kinks, and defect sites, and has extremely high catalytic activity.

[0102] Taking 151 mg / L actual beneficiation COD wastewater as an example, the dosage relationship between manganese tantalate and sodium persulfate aqueous solution prepared in Examples 1, 2, 3 and Comparative Example 1 is 1:1 (m), and the performance curve of manganese tantalate for activating sodium persulfate to oxidize COD is as follows: Figure 7 As shown. After 30 minutes of reaction, the COD concentration in the solution of Comparative Example 1 was only reduced to 86 mg / L. Examples 1, 2, and 3 all had good treatment effects on COD, and the COD concentrations were reduced to 46, 43, and 40 mg / L, respectively. It can be seen that Example 3, i.e., the manganese carbonate with the (200) crystal face exposed, had the best effect.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0104] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and to form distinct embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is intended solely to enhance understanding of the overall background of this application and should not be construed as an admission or any implication that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing a supported manganese tantalate catalyst with controlled crystal surface, characterized in that: include: First mixing water and glycerol to prepare a mixed solution; performing a second mixing of the mixed solution with a manganese salt, an amino acid, a chlorine-containing pyridine compound, and activated alumina to obtain a reaction precursor; The reaction precursor and tantalum pentoxide are mixed for a third time and then heat-treated to obtain the manganese tantalate; The supported manganese tantalate catalyst comprises manganese tantalate and an activated alumina carrier, wherein the manganese tantalate is supported on the activated alumina carrier; the structure of the manganese tantalate comprises at least one of an octahedral structure, a nano-sheet ball structure, and a nano-flower ball structure; The manganese tantalate crystal exposes at least one of the crystal planes (621), (211), and (200).

2. The preparation method according to claim 1, characterized in that The volume ratio of the water to the glycerol is 1:0.5-1.

3. The preparation method according to claim 1, characterized in that The manganese salt includes at least one of manganese chloride, manganese sulfate and manganese acetate.

4. The preparation method according to claim 1, characterized in that At least one of the following conditions is met: a. The amino acids include alanine family amino acids; b. The activated alumina includes activated alumina balls.

5. The preparation method according to claim 4, characterized in that The alanine family amino acids include at least one of L-2-chlorophenylalanine, L-4-fluorophenylalanine, and ZL-alanine.

6. The preparation method according to claim 1, characterized in that The chlorine-containing pyridine compound includes at least one of 6-chloro-2-hydroxymethylpyridine, dodecylpyridinium chloride, and 2-chloro-3-hydroxypyridine.

7. The preparation method according to claim 1, characterized in that At least one of the following conditions is met: c. The amount of the manganese salt, the amino acid, the chlorine-containing pyridine compound and the activated alumina is 0.5-1.0 mmol: 0.2-0.4 g: 0.1-0.2 g: 0.3-0.5 g; d. The ratio of the mixed solution to the tantalum pentoxide is 15 mL: 1-2 mmol.

8. The preparation method according to claim 1, characterized in that The heat treatment is carried out under closed conditions, the temperature of the heat treatment is 100-140° C., and the time is 4-8 hours.

Images