A method for preparing ethyleneamine by reductive amination

Abstract

The present invention discloses a method for preparing ethyleneamine and reducing the piperazine content in the product. By preparing a low-temperature, high-activity catalyst, the method can achieve a feedstock conversion rate greater than 50% and a piperazine selectivity less than 16% at low temperatures. Furthermore, by adding a trace amount of hydrazine to the feedstock, the catalyst's activity and selectivity can be sustained.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and particularly relates to a method for preparing ethyleneamine. Background Art

[0002] Ethyleneamines are a collective term for ethylenediamine, diethylenetriamine, piperazine, hydroxyethylethylenediamine, aminoethylpiperazine, hydroxyethylpiperazine, and polyethylenepolyamines. This product family is widely used in papermaking, lubricant additives, chelating agents, curing agents, corrosion inhibitors, pharmaceutical intermediates, bleaching agents, surfactants, and other fields. The main preparation methods include the ethylene dichloride method, the direct amination method with ethanolamine, and the reductive amination method with ethanolamine. The reductive amination method with ethanolamine is currently the predominant production process due to its advantages of low waste, low energy consumption, and low waste production.

[0003] Due to the current optimization of the ethyleneamine industry structure and downstream demand, the market demand for chain ethyleneamine is increasing. However, the reductive amination of ethyleneamine produces a large amount of piperazine and its derivatives as by-products. Therefore, maintaining high catalyst activity and reducing piperazine series cyclic by-products are the main difficulties of this process.

[0004] Methods for optimizing product composition primarily focus on catalyst formulation development. For example, the catalyst and amine production method disclosed in invention patent CN1086314C includes active components such as Ni / Co / Cu / Re / B / Ru. Specifically, the introduction of Ru in this patent allows the catalyst to maintain selectivity for linear ethyleneamines at higher hydrogen concentrations. However, while higher hydrogen concentrations improve catalyst activity and lifespan, they also increase cyclic byproducts. While the introduction of precious metals can reduce cyclic byproducts to a certain extent, this increases catalyst cost. Furthermore, the ideal reaction temperature in this patent is ≥180°C. While high reaction temperatures improve conversion rates, they are detrimental to catalyst lifespan and increase energy consumption. Another example is invention patent CN114605268A, which introduces alkali metals such as Na and K into the catalyst to increase the basicity of the support, thereby suppressing deamination side reactions and reducing the production of cyclic amines such as piperazine. However, this method requires that the alkali metals, such as Na and K, be present in the form of oxides, and strict calcination temperature control is required; otherwise, abnormal catalyst activity may occur.

[0005] Optimizing process conditions to optimize product composition has also been reported. For example, patents such as US3766184A and US4123462A both add a certain amount of water to the raw materials to suppress the production of cyclic amines such as piperazine. However, the reductive amination reaction itself is a dehydration reaction, and the introduction of water into the raw materials can inhibit the activity of the primary reaction to a certain extent and increase the energy consumption of post-processing dehydration, making it impractical.

[0006] In summary, a new catalyst preparation method is needed to reduce the by-production of cyclic amines at a higher conversion rate and increase the catalyst life. Summary of the Invention

[0007] In view of the problem in the prior art that cyclic amine by-products are high in content and difficult to suppress, the object of the present invention is to provide a method for preparing ethyleneamine by reductive amination, wherein the catalyst used in the method has good activity, selectivity and stability at low temperature (160°C) and low hydrogen concentration (<1.0 mol%).

[0008] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is as follows:

[0009] The present invention first provides a new catalyst, which comprises an active component, an auxiliary agent and a carrier;

[0010] Wherein, based on the mass of the carrier, the content of the metal element of the active component (the active component is converted into a metal element) is 10 to 300 wt%, preferably 100 to 200 wt%;

[0011] The content of the metal element in the additive (calculated as a single metal substance) is 1 to 100 wt %, preferably 10 to 20 wt %;

[0012] Wherein, the metal element of the active component is selected from one or more of Ni, Co, and Cu;

[0013] The metal element of the additive is selected from one or more of Cr, Mn, Fe, Zn, Sb, and Bi, preferably one or more of Mn, Fe, and Zn;

[0014] The carrier is selected from one or more of Al2O3, SiO2, and ZrO2, and the preferred carrier is Al2O3.

[0015] In the present invention, the preparation method of the catalyst comprises the following process:

[0016] (1) preparing a metal salt aqueous solution containing active component elements, auxiliary elements and a carrier precursor, and performing a precipitation reaction with a precipitant to obtain a catalyst slurry;

[0017] (2) filtering, washing, drying, and calcining the catalyst slurry obtained in step (1) to obtain catalyst raw powder;

[0018] (3) The catalyst powder obtained in step (2) is mixed evenly with a binder, an acidifier is added dropwise to a certain viscosity, and then the mixture is shaped and calcined to obtain a finished catalyst, which is then activated by hydrogen and subjected to an amination reaction.

[0019] In the preparation method, the metal salt in step (1) can be selected from inorganic salts such as nitrates, sulfates, halides, and hydrates of the corresponding metal, preferably nitrates and hydrates thereof; the total concentration of the metal salt in the salt solution is 5 to 30 wt%, preferably 15 to 25 wt%;

[0020] The precipitant can be selected from aqueous solutions of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, etc., preferably aqueous solutions of sodium carbonate and potassium carbonate; the concentration of the precipitant can be selected from 10 to 50 wt%, preferably 15 to 20 wt%;

[0021] The precipitation reaction temperature can be selected from 50 to 80°C, preferably 60 to 70°C; the precipitation reaction pH can be selected from 6 to 9, preferably 7 to 8;

[0022] In step (2), the catalyst slurry is washed with deionized water, and the washing standard is that the filtrate conductivity is less than 100 μS / cm, and the preferred filtrate conductivity is ≤20 μS / cm; the filter cake is dried at a temperature of 100 to 150°C, and the preferred drying temperature is 100 to 120°C; and the calcination temperature is 300 to 700°C, and the preferred temperature is 450 to 600°C.

[0023] In step (3), the binder can be selected from 20-30% concentration of silica sol, boehmite, pseudo-boehmite, preferably boehmite, pseudo-boehmite, and the amount of the binder is 2-50wt% of the original powder mass, preferably 5-10wt%;

[0024] The acidulant is an aqueous solution of an unsaturated organic acid such as acrylic acid, crotonic acid, maleic acid, salicylic acid, or benzoic acid, with a concentration of 2 to 30 wt %, preferably 5 to 10 wt %. The amount of the acidulant is not particularly limited, as long as it allows the viscosity of the raw powder to meet the molding requirements.

[0025] Forming can be performed by tableting or extrusion, with extrusion being preferred. The diameter of the formed catalyst can be 3 mm, 5 mm, etc. After forming, the catalyst is further calcined at a temperature of 300-700°C, preferably 400-500°C. The calcination atmosphere can be air or nitrogen, with nitrogen being preferred.

[0026] The second aspect of the present invention relates to the use of the above catalyst in the preparation of ethyleneamine.

[0027] A method for preparing vinylamine by reductive amination, comprising:

[0028] Using ethanolamine and liquid ammonia as raw materials and hydrazine as auxiliary agent, vinylamine is prepared by reductive amination in the presence of the above catalyst under hydrogen conditions;

[0029] The catalyst is firstly reduced and activated at a temperature of 220 to 450° C., preferably 230 to 250° C.

[0030] The molar ratio of ethanolamine to liquid ammonia is 1:6 to 20, preferably 1:8 to 15;

[0031] The amount of hydrazine added as an auxiliary agent is 50 to 1000 ppm, preferably 100 to 500 ppm, based on the total mass of ethanolamine / liquid ammonia;

[0032] The reaction temperature is 140-200°C, preferably 150-165°C; the pressure is 8-20 MPa, preferably 8-15 MPa;

[0033] The mass space velocity of ethanolamine is 0.1~1.5h -1 , the preferred mass space velocity is 0.2~0.5h -1 ;

[0034] The hydrogen concentration is 0.1 to 1.0 mol%, preferably 0.2 to 0.5 mol%, based on the total molar amount of ethanolamine / liquid ammonia.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] By adding an appropriate amount of additive to the catalyst, the additive is ultimately distributed on the catalyst surface in the form of oxides, which helps to improve the dispersion of the active metal, thereby increasing the activity of the catalyst at low temperatures and reducing the formation of cyclic amines that are more easily formed at high temperatures. At low temperatures, a feedstock conversion rate of >50% and a piperazine selectivity of <16% can be achieved.

[0037] By introducing organic acid during the catalyst forming process and calcining it in a nitrogen environment to form carbides such as Ni3C with some active metals, the catalyst's anti-sintering ability is improved, thereby improving the catalyst's stability;

[0038] Finally, by adding a small amount of the strong reducing agent hydrazine to the raw materials, the catalyst can be continuously activated during the reaction, reducing the content of metal nitrides on the catalyst surface. Therefore, long-term operation at a low hydrogen concentration can be achieved, thereby reducing the content of piperazine cyclic by-products. In addition, hydrazine can be decomposed into N2 and H2 at high temperatures, without the need for special post-treatment, and has certain operability. DETAILED DESCRIPTION

[0039] In order to better understand the technical solution of the present invention, the following examples will further illustrate the method provided by the present invention, but the present invention is not limited to the listed examples, and should also include any other known changes within the scope of the claims of the present invention.

[0040] The present invention is further explained below by more specific examples, but does not constitute any limitation.

[0041] Source of raw materials:

[0042] raw material purity / % Supplier liquid ammonia 98.0 Kermel <![CDATA[H2]]> >99.99 Wanhua Ethanolamine 99.0 Innochem Hydrazine 98.0 Innochem Nickel nitrate hexahydrate 99.0 Comeau Cobalt nitrate hexahydrate 98.0 Comeau Copper nitrate 98.0 Aladdin Aluminum nitrate nonahydrate 98.0 Aladdin Manganese nitrate tetrahydrate 99.0 Innochem Ferric nitrate nonahydrate 99.0 Innochem Zinc nitrate hexahydrate 98.0 Innochem

[0043] The gas chromatography analysis conditions of the reaction liquid components in the following examples are: Agilent DB-5 chromatographic column, inlet temperature 280°C, FID detector temperature 300°C, column flow rate 1.5 ml / min, hydrogen flow rate 30 ml / min, air flow rate 400 ml / min, and programmed temperature rise mode: hold at 50°C for 2 min, increase the temperature to 80°C at 5°C / min, then increase the temperature to 280°C at 15°C / min and hold for 10 min.

[0044] Reactor parameters: tube length 1000 mm, inner diameter 22 mm, wall thickness 5 mm, heated by electric heating jacket.

[0045] Example 1

[0046] S1: Catalyst preparation.

[0047] Add nickel nitrate hexahydrate, cobalt nitrate hexahydrate, copper nitrate, manganese nitrate tetrahydrate, iron nitrate nonahydrate, and aluminum nitrate nonahydrate into a glass container, respectively, and then add deionized water to prepare a salt solution with a concentration of 20 wt%;

[0048] Prepare a 15 wt% sodium carbonate aqueous solution;

[0049] The salt solution and alkaline solution were added dropwise to the container with stirring, maintaining the temperature at 65°C. A pH meter was used to monitor the mixed solution's pH in the range of 7-8. After the addition was complete, the resulting suspension was filtered and washed with deionized water until the conductivity of the washings was less than 20 μS / cm. The filter cake was dried in a drying oven at 120°C and then calcined at 500°C for 5 hours to obtain the catalyst powder. The ratios of various elements in the Al2O3 are shown in Table 1.

[0050] 100 g of the raw powder prepared above was evenly mixed with 20 g of 30% silica sol, and 8 wt% acrylic acid aqueous solution was added dropwise for acidification. During the acidification process, the acid solution was added dropwise while the raw powder was stirred. When the viscosity of the raw powder reached the extrusion standard, the addition was stopped, and 3 mm strips were extruded. After drying in the shade for 24 hours, the strips were calcined at 500°C in a nitrogen atmosphere for 3 hours to obtain catalyst No. 1.

[0051] S2: reductive amination reaction.

[0052] 50 g of the above-mentioned formed catalyst was loaded into a reaction tube and activated under pure hydrogen conditions at 230° C. for 24 h before reacting.

[0053] Reaction conditions: 155°C, 13 MPa, ethanolamine mass space velocity of 0.35 h -1 , the NH3 / MEA molar ratio is 8:1, the molar concentration of hydrogen relative to the total amount of raw materials is 0.25%, and the amount of hydrazine added is 100 ppm.

[0054] After 24 h of continuous operation, samples were taken for GC analysis. The reaction results are summarized in Table 1.

[0055] Example 2

[0056] S1: Catalyst preparation.

[0057] Add nickel nitrate hexahydrate, copper nitrate, manganese nitrate tetrahydrate, iron nitrate nonahydrate, zinc nitrate hexahydrate, and aluminum nitrate nonahydrate to a glass container, then add deionized water to prepare a 20 wt% salt solution. Prepare a 10 wt% sodium carbonate aqueous solution.

[0058] The salt solution and alkaline solution were added dropwise to the container with stirring, maintaining the temperature at 70°C. A pH meter was used to monitor the mixed solution's pH within the range of 6-7. After the addition was complete, the resulting suspension was filtered and washed with deionized water until the conductivity of the washings was less than 20 μS / cm. The filter cake was dried in a drying oven at 120°C and then calcined at 450°C for 5 hours to obtain the catalyst powder. The ratios of various elements in the Al2O3 are shown in Table 1.

[0059] 100 g of the raw powder prepared above was evenly mixed with 15 g of boehmite, and 10 wt% of a crotonic acid aqueous solution was added dropwise to the raw powder and binder for acidification. The raw powder was stirred while the acid solution was added dropwise. When the viscosity reached the molding condition, the addition was stopped, and 5 mm extrusion strips were formed. After drying in the shade for 24 hours, the catalyst was calcined at 450°C in a nitrogen atmosphere for 3 hours to obtain catalyst #2.

[0060] S2: reductive amination reaction.

[0061] 50 g of the above-mentioned formed catalyst was loaded into a reaction tube and activated under pure hydrogen conditions at 250° C. for 24 h before reacting.

[0062] The reaction conditions are: 150°C, 14 MPa, and ethanolamine mass space velocity of 0.2 h -1 , the NH3 / MEA molar ratio is 12:1, the molar concentration of hydrogen relative to the total amount of raw materials is 0.2%, and the amount of hydrazine added is 500 ppm.

[0063] After 24 h of continuous operation, samples were taken for GC analysis. The reaction results are summarized in Table 1.

[0064] Example 3

[0065] S1: Catalyst preparation.

[0066] Add cobalt nitrate hexahydrate, copper nitrate, iron nitrate nonahydrate, zinc nitrate hexahydrate, and aluminum nitrate nonahydrate to a glass container, then add deionized water to prepare a 10 wt% salt solution. Prepare a 20 wt% potassium carbonate aqueous solution.

[0067] The salt solution and alkaline solution were added dropwise to the container with stirring, maintaining the temperature at 70°C. A pH meter was used to monitor the mixed solution's pH in the range of 6 to 8. After the addition was complete, the resulting suspension was filtered and washed with deionized water until the conductivity of the washings was less than 20 μS / cm. The filter cake was dried in a drying oven at 120°C and then calcined at 600°C for 5 hours to obtain the catalyst powder. The ratios of various elements in the Al2O3 are shown in Table 1.

[0068] 100 g of the raw powder prepared above was evenly mixed with 18 g of pseudo-boehmite, and 15 wt% maleic acid aqueous solution was dripped into the raw powder and binder while stirring. When the viscosity reached the molding condition, the dripping was stopped, and 3 mm extrusion molding was performed. After drying in the shade for 24 hours, the catalyst was calcined at 450 ° C in a nitrogen atmosphere for 3 hours to obtain catalyst #3.

[0069] S2: reductive amination reaction.

[0070] 50 g of the above-mentioned formed catalyst was loaded into a reaction tube and activated under pure hydrogen conditions at 240° C. for 24 h before reacting.

[0071] The reaction conditions are: 165°C, 12 MPa, and ethanolamine mass space velocity of 0.5 h -1 , the NH3 / MEA molar ratio is 15:1, the molar concentration of hydrogen relative to the total amount of raw materials is 1%, and the amount of hydrazine added is 100 ppm.

[0072] After 24 h of continuous operation, samples were taken for GC analysis. The reaction results are summarized in Table 1.

[0073] Example 4

[0074] S1: Catalyst preparation.

[0075] Add nickel nitrate hexahydrate, cobalt nitrate hexahydrate, manganese nitrate tetrahydrate, zinc nitrate hexahydrate, and aluminum nitrate nonahydrate to a glass container, then add deionized water to prepare a 20 wt% salt solution. Prepare a 15 wt% potassium carbonate aqueous solution.

[0076] The salt solution and alkaline solution were added dropwise to the container with stirring, maintaining the temperature at 70°C. A pH meter was used to monitor the mixed solution's pH within the range of 7-9. After the addition was complete, the resulting suspension was filtered and washed with deionized water until the conductivity of the washings was less than 20 μS / cm. The filter cake was dried in a drying oven at 120°C and then calcined at 550°C for 5 hours to obtain the catalyst powder. The ratios of various elements in the Al2O3 solution are shown in Table 1.

[0077] Mix 100 g of the raw powder prepared above with 15 g of boehmite evenly, add 7 wt% salicylic acid aqueous solution to the raw powder and binder, and stir while adding the acid solution to acidify. Stop adding when the viscosity reaches the molding condition, and perform 3 mm extrusion molding. After drying in the shade for 24 hours, calcinate at 400°C in a nitrogen atmosphere for 3 hours to obtain catalyst #4.

[0078] S2: reductive amination reaction.

[0079] 50g of the above-mentioned shaped catalyst was loaded into a reaction tube and activated under pure hydrogen at 250℃ for 24h before reaction. The reaction conditions were: 160℃, 14MPa, and ethanolamine mass space velocity of 0.5h -1 , the NH3 / MEA molar ratio is 10:1, the molar concentration of hydrogen relative to the total amount of raw materials is 0.1%, and the amount of hydrazine added is 350 ppm.

[0080] After 24 h of continuous operation, samples were taken for GC analysis. The reaction results are summarized in Table 1.

[0081] Example 5

[0082] S1: Catalyst preparation.

[0083] Add nickel nitrate hexahydrate, cobalt nitrate hexahydrate, copper nitrate, manganese nitrate tetrahydrate, iron nitrate nonahydrate, zinc nitrate hexahydrate, and aluminum nitrate nonahydrate to a glass container, then add deionized water to prepare a 20 wt% salt solution. Prepare a 15 wt% sodium carbonate aqueous solution.

[0084] The salt solution and alkaline solution were added dropwise to the container with stirring, maintaining the temperature at 70°C. A pH meter was used to monitor the mixed solution's pH within the range of 7-9. After the addition was complete, the resulting suspension was filtered and washed with deionized water until the conductivity of the washings was less than 20 μS / cm. The filter cake was dried in a drying oven at 120°C and then calcined at 500°C for 5 hours to obtain the catalyst powder. The ratios of various elements in the Al2O3 are shown in Table 1.

[0085] 100 g of the raw powder prepared above was mixed evenly with 10 g of pseudo-boehmite. After mixing evenly, 6 wt% benzoic acid aqueous solution was added dropwise for acidification. The addition was stopped while stirring until the viscosity reached the extrusion standard. 3 mm extrusion strips were formed. After drying in the shade for 24 hours, they were calcined at 450°C in a nitrogen atmosphere for 3 hours to obtain catalyst #5.

[0086] S2: reductive amination reaction.

[0087] 50g of the above-mentioned formed catalyst was loaded into a reaction tube and activated under pure hydrogen at 250℃ for 24h before reaction. The reaction conditions were: 158℃, 8MPa, and ethanolamine mass space velocity of 0.4h -1The NH3 / MEA molar ratio was 13:1, the molar concentration of hydrogen relative to the total amount of the raw materials was 0.6%, and the amount of hydrazine added was 150 ppm. After 24 hours of continuous operation, samples were taken for GC analysis. The reaction results are summarized in Table 1.

[0088] Comparative Example 1

[0089] The present invention is different from Example 2 in that no additives such as Mn, Fe, and Zn are added to the catalyst.

[0090] S1: Catalyst Preparation. The preparation method is the same as that of Example 2, except that manganese nitrate tetrahydrate, iron nitrate nonahydrate, and zinc nitrate hexahydrate are not added, and the raw material addition amounts are changed. The proportions of various elements in Al2O3 are shown in Table 1.

[0091] S2: Reductive amination reaction. The reductive amination reaction conditions were the same as those in Example 2, except that the reaction temperature in Comparative Example 1 was 180°C.

[0092] Comparative Example 2

[0093] The present invention is different from Example 2 in that the catalyst is formed by acidification with inorganic acid nitric acid.

[0094] S1: Catalyst preparation: The preparation method is the same as that of Example 2, except that a 10 wt% nitric acid aqueous solution is used for acidification of the boehmite.

[0095] S2: reductive amination reaction. The reductive amination reaction conditions are consistent with those of Example 2.

[0096] Comparative Example 3

[0097] Compared with Example 2, the present invention is different in that no hydrazine is added in the reductive amination reaction.

[0098] The main reaction conditions and results of the embodiments and comparative examples are shown in the table below:

[0099]

[0100] English abbreviation comparison table:

[0101] MEA: ethanolamine

[0102] EDA: Ethylenediamine

[0103] PIP: Piperazine

[0104] DETA: Diethylenetriamine

[0105] NH3: ammonia.

[0106] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description is not intended to limit the present invention. Those skilled in the art will appreciate that, based on the teachings of this specification, modifications or adjustments may be made to the present invention. Such modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A method for preparing vinylamine by reductive amination, comprising: Using ethanolamine and liquid ammonia as raw materials and hydrazine as auxiliary agent, vinylamine is prepared by reductive amination in the presence of a catalyst under hydrogen conditions; The amount of hydrazine added is 50 to 1000 ppm, based on the total mass of ethanolamine / liquid ammonia; The catalyst comprises an active component, an auxiliary agent and a carrier; Wherein, based on the mass of the carrier, the content of the metal element of the active component is 10 to 300 wt%, and the content of the metal element of the auxiliary agent is 1 to 100 wt%; The metal element of the active component is one or more of Ni, Co, and Cu; the metal element of the auxiliary agent is one or more of Mn, Fe, and Zn; the carrier is one or more of Al2O3, SiO2, and ZrO2; The preparation method of the catalyst comprises the following steps: (1) preparing a metal salt aqueous solution containing the metal element of the active component, the metal element of the auxiliary agent, and the carrier precursor, and performing a precipitation reaction with a precipitant to obtain a catalyst slurry; (2) filtering, washing, drying, and calcining the catalyst slurry obtained in step (1) to obtain catalyst raw powder; (3) uniformly mixing the catalyst powder obtained in step (2) with a binder, adding an acidifier, and then shaping and calcining to obtain a finished catalyst; wherein the acidifier is selected from an aqueous solution of acrylic acid, crotonic acid, maleic acid, salicylic acid, and benzoic acid.

2. The method according to claim 1, wherein Based on the mass of the carrier, the content of the metal element in the active component is 100-200 wt%, and the content of the metal element in the auxiliary agent is 10-20 wt%; The metal element of the auxiliary agent is one or more of Mn, Fe, and Zn; and the carrier is Al2O3.

3. The method according to claim 1 or 2, wherein: The catalyst is firstly reduced and activated at a temperature of 220-450°C.

4. The method according to claim 3, wherein: The reduction activation temperature is 230-250°C.

5. The method according to claim 1, wherein The molar ratio of ethanolamine to liquid ammonia is 1:6 to 20; The mass space velocity of ethanolamine is 0.1~1.5h -1 ; The hydrogen concentration is 0.1 to 1.0 mol%, based on the total molar amount of ethanolamine / liquid ammonia.

6. The method according to claim 5, wherein: The molar ratio of ethanolamine to liquid ammonia is 1:8-15.

7. The method according to claim 1, wherein The amount of hydrazine added is 100 to 500 ppm, based on the total mass of ethanolamine / liquid ammonia.

8. The method according to claim 1, wherein The reductive amination reaction temperature is 140-200° C.; the pressure is 8-20 MPa.

9. The method according to claim 8, wherein The reductive amination reaction temperature is 150-165° C.; the pressure is 8-15 MPa.

10. The method according to claim 1, wherein: The metal salt in step (1) is selected from nitrates, sulfates, and halides of the corresponding metals; and the precipitant is selected from aqueous solutions of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, and potassium carbonate.

11. The method according to claim 10, wherein: In step (1), the total concentration of the metal salt in the metal salt aqueous solution is 5 to 30 wt%; The concentration of the precipitant is 10 to 50 wt%.

12. The method according to claim 10, wherein: In step (1), the precipitation reaction temperature is 50-80° C., and the precipitation reaction pH is 6-9.

13. The method according to claim 1, wherein: In step (2), the drying temperature is 100-150°C; and the calcination temperature is 300-700°C.

14. The method according to claim 1, wherein: In step (3), the binder is selected from silica sol, boehmite, and pseudo-boehmite; the amount of the binder is 2 to 50 wt% of the original powder mass.

15. The method according to claim 14, wherein: In step (3), the amount of binder used is 5 to 10 wt% of the original powder mass.

16. The method according to claim 1, wherein: In step (3), the concentration of the acidifying agent is 2 to 30 wt %; The calcination temperature is 300-700°C.

17. The method according to claim 16, wherein: In step (3), the concentration of the acidifier is 5 to 10 wt%.

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