A method for preparing a spherical alpha-alumina catalyst carrier

Abstract

The present invention discloses a method for preparing a spherical α-alumina catalyst carrier, comprising: (1) preparing aluminum oxide seed crystals; (2) modifying the aluminum oxide seed crystals to obtain modified seed crystals; (3) preparing a promoter; (4) configuring an aluminum nitrate solution; adding the modified seed crystals and the promoter to the aluminum nitrate solution, and then adding an ammonia solution to obtain a precipitate, washing the precipitate, drying, and calcining to obtain the α-alumina catalyst carrier. The α-alumina catalyst carrier prepared by the method of the present invention has a large specific surface area, can be used to attach more catalyst active ingredients, and increases the specific surface area of ​​the catalyst active ingredients, thereby increasing the number of catalytically active sites.

Description

Technical Field

[0001] The invention belongs to the technical field of catalyst materials, and in particular relates to a method for preparing a spherical alpha-alumina catalyst carrier. Background Art

[0002] Alumina (Al2O3) is widely used in various new functional materials, electronics, and biomedicine fields due to its high mechanical strength, excellent insulation properties, corrosion resistance, high temperature resistance, and excellent chemical stability. Alumina, a highly abundant oxide in the Earth's crust, is found in soil, rocks, aquifers, and aquatic environments. my country, with abundant bauxite resources, is the world's largest producer of alumina. Industries such as ceramics, pharmaceuticals, electronics, and machinery are poised for rapid growth, significantly increasing market demand for alumina-related products and driving continued growth in alumina production. Alumina has many isomorphs, with common crystal forms including α, γ, χ, θ, η, and ρ. Among them, α-Al2O3 is the most stable and a key product of the alumina industry. α-Al2O3 is a metal oxide with a hexagonal, close-packed crystal structure and high lattice energy. It possesses excellent physical and chemical properties, including strong intermolecular cohesion, dense structure, and well-defined crystals, making it capable of withstanding various chemical changes. α-Al2O3 also boasts a high melting point (2050°C), high hardness, excellent insulation properties, high mechanical strength, good wear resistance, and high heat and thermal shock resistance. It is widely used in metallurgy, ceramics, adsorption, catalysis, optical materials, and biomedicine, and has broad application prospects. α-Al2O3 powders with narrow particle size distribution and good dispersibility have long been a hot topic of research. Currently, methods for preparing spherical α-Al2O3 powders include homogeneous precipitation, hydrothermal method, drop ball method, template method, spray method, and plasma electrolysis. Summary of the Invention

[0003] Based on this, the present invention provides a method for preparing a spherical α-alumina catalyst carrier, comprising the following steps:

[0004] (1) passing aluminum hydroxide powder through a 1000-mesh sieve, collecting the sieved powder, and uniformly mixing the sieved powder with an aqueous solution of polyethylene glycol in a reactor to obtain a mixture, drying the mixture at 100° C. for 30 to 40 minutes, and then air-cooling it to room temperature. Adding an aqueous solution of urea, lignin, and aluminum fluoride to the reactor, uniformly mixing the mixture after the addition is completed, and then drying it at 100° C. for 30 to 40 minutes. Then, heating it to 1200° C. in a muffle furnace and calcining it for more than 20 hours, air-cooling it to room temperature, ball-milling it, and passing it through a 1000-mesh sieve to obtain aluminum oxide seed crystals;

[0005] (2) preparing an acetic acid solution of chitosan, adding the alumina seed crystals to the acetic acid solution of chitosan to form a suspension, keeping the suspension constant at 40±2°C in a water bath, and then stirring the suspension. During the stirring process, an aqueous solution of glutaraldehyde is added to the suspension. After the addition is completed, the suspension is stirred at a constant temperature of 40±2°C for more than 2 hours, and then the solid-liquid separation is carried out. The solid phase is washed with acetic acid solution for more than 3 times, and then washed with deionized water for more than 3 times, and dried to obtain a dried solid phase; preparing an aqueous solution of diethylenetriamine pentaacetic acid, stirring the aqueous solution of diethylenetriamine pentaacetic acid, and adding glutaraldehyde to the solution during the stirring process. 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide were added, and after the addition was completed, the solution was stirred for more than 2 hours to obtain a modified solution; the modified solution was kept constant temperature at 80±2° C. in a water bath, and then the dried solid phase was added to the modified solution to form a suspension, and the suspension was stirred at a constant temperature of 80±2° C. for more than 30 minutes, and then diethylenetriamine was added to the suspension under stirring. After the addition was completed, the solution was stirred at a constant temperature of 80±2° C. for more than 5 hours, and then air-cooled to room temperature, solid-liquid separation was performed, and the solid phase was washed with deionized water for more than 4 times, and dried to obtain modified seed crystals;

[0006] (3) preparing an aqueous solution of dodecyl glucoside, keeping the aqueous solution of dodecyl glucoside constant temperature at 60±3°C in a water bath, and then stirring the solution. During the stirring process, diethylene glycol diglycidyl ether and ethylene glycol are added to the aqueous solution of dodecyl glucoside. After the addition is completed, the solution is stirred at a constant temperature of 60±3°C for more than 10 minutes. Then, sodium hydroxide solution is added dropwise to the solution under stirring. After the addition is completed, the solution is stirred at a constant temperature of 60±3°C for 2-3 hours. Then, the solution is air-cooled to room temperature, the pH is adjusted to neutral with 5wt% hydrochloric acid, and the solution is concentrated under reduced pressure to obtain a promoter.

[0007] (4) preparing an aluminum nitrate solution, adding the modified seed crystals and the promoter to the aluminum nitrate solution to obtain a mixed solution; stirring the mixed solution, adding an ammonia solution to the mixed solution while stirring to adjust the pH of the mixed solution to 7, and then stirring the mixed solution for more than 30 minutes, separating the solid and the liquid, washing the solid phase with deionized water for more than 2 times, and then washing with ethanol for more than 2 times, drying at 60°C, calcining the dried solid phase at a temperature of 1300-1340°C for 2 hours, and air-cooling to room temperature to obtain the α-alumina catalyst carrier.

[0008] Furthermore, in the step (1), the mass percentage of polyethylene glycol in the polyethylene glycol aqueous solution is 3% to 5%, and the solvent is water; the mass ratio of the sieved powder to the polyethylene glycol aqueous solution is sieved powder: polyethylene glycol aqueous solution = 10:4-5.

[0009] Furthermore, in step (1), the mass ratio of the added mass of the urea aqueous solution, lignin and aluminum fluoride to the aluminum hydroxide in the mixture is urea aqueous solution: lignin: aluminum fluoride: aluminum hydroxide = 3-4:1:0.6-0.9:10; wherein the mass percentage of urea in the urea aqueous solution is 5%, and the solvent is water.

[0010] Furthermore, in the step (2), the chitosan acetic acid solution is prepared by mixing chitosan and acetic acid solution in a ratio of chitosan / acetic acid solution = 2 to 3 g / 100 mL, and the mass fraction of the solute in the acetic acid solution is 2%; the alumina seeds are added to the chitosan acetic acid solution to form a suspension at a solid-liquid ratio of alumina seeds / chitosan acetic acid solution = 0.2 to 0.3 g: 100 mL; the mass ratio of the added glutaraldehyde aqueous solution to the mass of the alumina seeds in the suspension is alumina seeds: glutaraldehyde aqueous solution = 1:2 to 3, and the mass percentage of glutaraldehyde in the glutaraldehyde aqueous solution is 15% to 18%.

[0011] Furthermore, in the step (2), the concentration of diethylenetriamine pentaacetic acid in the aqueous solution is 150-200 mg / 100 mL, and the amount ratio of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide added to the aqueous solution of diethylenetriamine pentaacetic acid is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride: N-hydroxysuccinimide: aqueous solution of diethylenetriamine pentaacetic acid = 90-100 mg: 40-50 mg: 100 mL; the dried solid phase is added to the modified liquid at a solid-liquid mass ratio of solid / liquid = 1:80; the added volume of the diethylenetriamine is the suspension volume ratio of diethylenetriamine: suspension = 2-4 mL: 100 mL.

[0012] Furthermore, in the step (3), the concentration of dodecyl glucoside in the aqueous solution of dodecyl glucoside is 10-14 g / 100 mL, and diethylene glycol diglycidyl ether, ethylene glycol and sodium hydroxide solution are added to the aqueous solution of dodecyl glucoside in a ratio of dodecyl glucoside aqueous solution: diethylene glycol diglycidyl ether: ethylene glycol: sodium hydroxide solution = 100 mL: 10-12 g: 18-20 g: 4-9 mL, the concentration of sodium hydroxide in the sodium hydroxide solution is 4-5 g / 100 mL, and the solvent is water.

[0013] Furthermore, in step (4), the concentration of aluminum nitrate in the aluminum nitrate solution is 0.5-0.7 g / 100 mL, and the solvent is water; the modified seed crystals and the promoter are added to the aluminum nitrate solution in a ratio of aluminum nitrate solution: modified seed crystals: promoter = 100 mL: 0.8-1.4 g: 3-5 mL.

[0014] Furthermore, in step (4), the mass percentage of the solute in the ammonia solution is 25%.

[0015] The beneficial effects of the present invention are that the α-alumina catalyst carrier prepared by the method of the present invention has a large specific surface area, can be used to attach more catalytic active ingredients, and increases the specific surface area of ​​the catalytic active ingredients and the number of catalytic active sites. DETAILED DESCRIPTION

[0016] The following is a detailed description with reference to the embodiments:

[0017] Example 1

[0018] A method for preparing a spherical α-alumina catalyst carrier comprises the following steps:

[0019] (1) Aluminum hydroxide powder is passed through a 1000-mesh sieve, and the sieved powder is collected. The sieved powder is mixed uniformly with an aqueous solution of polyethylene glycol (PEG-1000) in a reactor to obtain a mixture, wherein the mass percentage of polyethylene glycol in the aqueous solution of polyethylene glycol is 3%, and the solvent is water; the mass ratio of the sieved powder to the aqueous solution of polyethylene glycol is sieved powder: aqueous solution of polyethylene glycol = 10:4; the mixture is dried at 100°C for 30 minutes, and then air-cooled to room temperature, and an aqueous solution of urea is added to the reactor. liquid, lignin and aluminum fluoride, the mass ratio of the added urea aqueous solution, lignin and aluminum fluoride to the aluminum hydroxide in the mixture is urea aqueous solution: lignin: aluminum fluoride: aluminum hydroxide = 3:1:0.6:10; wherein the mass percentage of urea in the urea aqueous solution is 5%, and the solvent is water; after the addition is completed, the mixture is mixed evenly, dried at 100° C. for 30 minutes, then heated to 1200° C. in a muffle furnace and calcined for 20 hours, air-cooled to room temperature, ball-milled, and passed through a 1000-mesh sieve to obtain alumina seed crystals;

[0020] (2) preparing an acetic acid solution of chitosan, wherein the acetic acid solution of chitosan is prepared by mixing chitosan and acetic acid solution in a ratio of chitosan / acetic acid solution = 2 g / 100 mL, wherein the mass fraction of solute in the acetic acid solution is 2%; adding the alumina seed crystals to the acetic acid solution of chitosan to form a suspension, wherein the solid-liquid ratio of the alumina seed crystals to the acetic acid solution of chitosan to form a suspension is alumina seed crystals / chitosan acetic acid solution = 0.2 g:100 mL; the suspension is kept in a water bath at a constant temperature of 40±2° C., and then the suspension is stirred, and pentane is added to the suspension during the stirring process. The mass ratio of the added mass of the aqueous solution of glutaraldehyde to the mass of the alumina seeds in the suspension is alumina seeds: glutaraldehyde aqueous solution = 1:2, and the mass percentage of glutaraldehyde in the aqueous solution of glutaraldehyde is 15%; after the addition is completed, the suspension is stirred at a constant temperature of 40±2°C for 2h, and then the solid-liquid is separated, the solid phase is washed 3 times with acetic acid solution, and then washed 3 times with deionized water, and dried to obtain a dried solid phase; an aqueous solution of diethylenetriamine pentaacetic acid is prepared, and the concentration of diethylenetriamine pentaacetic acid in the aqueous solution of diethylenetriamine pentaacetic acid is 150mg / 100mL, and stirred The aqueous solution of diethylenetriamine pentaacetic acid is added with 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide during stirring, and the amount ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide to the aqueous solution of diethylenetriamine pentaacetic acid is 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride: N-hydroxysuccinimide: aqueous solution of diethylenetriamine pentaacetic acid = 90 mg: 40 mg: 100 mL; after the addition is completed, the solution is stirred for 2 hours to obtain a modified solution; the modified solution is added with 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide in a ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride: N-hydroxysuccinimide: aqueous solution of diethylenetriamine pentaacetic acid = 90 mg: 40 mg: 100 mL; after the addition is completed, the solution is stirred for 2 hours to obtain a modified solution; The modified liquid is kept at a constant temperature of 80±2° C. in a water bath, and then the dried solid phase is added to the modified liquid to form a suspension, and the solid-liquid mass ratio of the dried solid phase to the modified liquid is solid / liquid = 1:80; the suspension is stirred at a constant temperature of 80±2° C. for 30 minutes, and then diethylenetriamine is added to the suspension under stirring, and the added volume of the diethylenetriamine is the suspension volume ratio of diethylenetriamine: suspension = 2 mL: 100 mL; after the addition is completed, the mixture is continued to be stirred at a constant temperature of 80±2° C. for 5 hours, and then air-cooled to room temperature, solid-liquid separation is carried out, and the solid phase is washed 4 times with deionized water and dried to obtain modified seed crystals;

[0021] (3) preparing an aqueous solution of dodecyl glucoside, wherein the concentration of dodecyl glucoside in the aqueous solution is 10 g / 100 mL, and keeping the aqueous solution of dodecyl glucoside constant at 60±3° C. in a water bath, and then stirring the solution. During the stirring process, diethylene glycol diglycidyl ether and ethylene glycol are added to the aqueous solution of dodecyl glucoside. After the addition is completed, the solution is stirred at a constant temperature of 60±3° C. for 10 minutes, and then sodium hydroxide solution is added dropwise to the solution under stirring to add the dodecyl glucoside solution. Adding diethylene glycol diglycidyl ether, ethylene glycol, and sodium hydroxide solution to an aqueous solution in a ratio of dodecyl glucoside aqueous solution: diethylene glycol diglycidyl ether: ethylene glycol: sodium hydroxide solution = 100 mL: 10 g: 18 g: 4 mL, wherein the concentration of sodium hydroxide in the sodium hydroxide solution is 4 g / 100 mL, and the solvent is water; after the dropwise addition is completed, the solution is stirred at a constant temperature of 60±3° C. for 2 hours, then air-cooled to room temperature, the pH is adjusted to neutral with 5 wt % hydrochloric acid, and the solution is concentrated under reduced pressure to 1 / 3 of the volume before concentration to obtain a promoter;

[0022] (4) preparing an aluminum nitrate solution, wherein the concentration of aluminum nitrate in the aluminum nitrate solution is 0.6 g / 100 mL, and the solvent is water; adding the modified seed crystals and the promoter to the aluminum nitrate solution to obtain a mixed solution; adding the modified seed crystals and the promoter to the aluminum nitrate solution in a ratio of aluminum nitrate solution: modified seed crystals: promoter = 100 mL: 0.8 g: 3 mL; stirring the mixed solution, and adding an ammonia aqueous solution to the mixed solution under stirring to adjust the pH of the mixed solution to 7, wherein the mass percentage of the solute in the ammonia aqueous solution is 25%; then stirring the mixed solution for 30 minutes, separating the solid and the liquid, washing the solid phase twice with deionized water, washing twice with ethanol, drying at 60°C, calcining the dried solid phase at 1300°C for 2 hours, and air cooling to room temperature to obtain the α-alumina catalyst carrier.

[0023] Example 2

[0024] A method for preparing a spherical α-alumina catalyst carrier comprises the following steps:

[0025] (1) Aluminum hydroxide powder is passed through a 1000-mesh sieve, and the sieved powder is collected. The sieved powder is mixed uniformly with an aqueous solution of polyethylene glycol (PEG-1000) in a reactor to obtain a mixture, wherein the mass percentage of polyethylene glycol in the aqueous solution of polyethylene glycol is 3%, and the solvent is water; the mass ratio of the sieved powder to the aqueous solution of polyethylene glycol is sieved powder: aqueous solution of polyethylene glycol = 10:4; the mixture is dried at 100°C for 30 minutes, and then air-cooled to room temperature, and an aqueous solution of urea is added to the reactor. liquid, lignin and aluminum fluoride, the mass ratio of the added urea aqueous solution, lignin and aluminum fluoride to the aluminum hydroxide in the mixture is urea aqueous solution: lignin: aluminum fluoride: aluminum hydroxide = 3:1:0.7:10; wherein the mass percentage of urea in the urea aqueous solution is 5%, and the solvent is water; after the addition is completed, the mixture is mixed evenly, dried at 100° C. for 30 minutes, then heated to 1200° C. in a muffle furnace and calcined for 20 hours, air-cooled to room temperature, ball-milled, and passed through a 1000-mesh sieve to obtain alumina seed crystals;

[0026] (2) preparing an acetic acid solution of chitosan, wherein the acetic acid solution of chitosan is prepared by mixing chitosan and acetic acid solution in a ratio of chitosan / acetic acid solution = 2 g / 100 mL, wherein the mass fraction of solute in the acetic acid solution is 2%; adding the alumina seed crystals to the acetic acid solution of chitosan to form a suspension, wherein the solid-liquid ratio of the alumina seed crystals to the acetic acid solution of chitosan to form a suspension is alumina seed crystals / chitosan acetic acid solution = 0.2 g:100 mL; the suspension is kept in a water bath at a constant temperature of 40±2° C., and then the suspension is stirred, and pentane is added to the suspension during the stirring process. The mass ratio of the added mass of the aqueous solution of glutaraldehyde to the mass of the alumina seeds in the suspension is alumina seeds: glutaraldehyde aqueous solution = 1:2, and the mass percentage of glutaraldehyde in the aqueous solution of glutaraldehyde is 16%; after the addition is completed, the suspension is stirred at a constant temperature of 40±2°C for 2h, and then the solid-liquid is separated, the solid phase is washed 3 times with acetic acid solution, and then washed 3 times with deionized water, and dried to obtain a dried solid phase; an aqueous solution of diethylenetriamine pentaacetic acid is prepared, and the concentration of diethylenetriamine pentaacetic acid in the aqueous solution of diethylenetriamine pentaacetic acid is 180mg / 100mL, and stirred The aqueous solution of diethylenetriamine pentaacetic acid is added with 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide during stirring, and the amount ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide to the aqueous solution of diethylenetriamine pentaacetic acid is 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride: N-hydroxysuccinimide: aqueous solution of diethylenetriamine pentaacetic acid = 90 mg: 40 mg: 100 mL; after the addition is completed, the solution is stirred for 2 hours to obtain a modified solution; the modified solution is added with 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide in a ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride: N-hydroxysuccinimide: aqueous solution of diethylenetriamine pentaacetic acid = 90 mg: 40 mg: 100 mL; after the addition is completed, the solution is stirred for 2 hours to obtain a modified solution; The modified liquid is kept at a constant temperature of 80±2° C. in a water bath, and then the dried solid phase is added to the modified liquid to form a suspension, and the solid-liquid mass ratio of the dried solid phase to the modified liquid is solid / liquid=1:80; the suspension is stirred at a constant temperature of 80±2° C. for 30 minutes, and then diethylenetriamine is added to the suspension under stirring, and the added volume of the diethylenetriamine is the suspension volume ratio of diethylenetriamine:suspension=3mL:100mL; after the addition is completed, the mixture is continued to be stirred at a constant temperature of 80±2° C. for 5 hours, and then air-cooled to room temperature, solid-liquid separation is carried out, and the solid phase is washed 4 times with deionized water and dried to obtain modified seed crystals;

[0027] (3) preparing an aqueous solution of dodecyl glucoside, wherein the concentration of dodecyl glucoside in the aqueous solution is 12 g / 100 mL, and keeping the aqueous solution of dodecyl glucoside constant at 60±3° C. in a water bath, and then stirring the solution. During the stirring process, diethylene glycol diglycidyl ether and ethylene glycol are added to the aqueous solution of dodecyl glucoside. After the addition is completed, the solution is stirred at a constant temperature of 60±3° C. for 10 minutes, and then sodium hydroxide solution is added dropwise to the solution under stirring. Adding diethylene glycol diglycidyl ether, ethylene glycol, and sodium hydroxide solution to an aqueous solution in a ratio of dodecyl glucoside aqueous solution: diethylene glycol diglycidyl ether: ethylene glycol: sodium hydroxide solution = 100 mL: 11 g: 19 g: 7 mL, wherein the concentration of sodium hydroxide in the sodium hydroxide solution is 4 g / 100 mL, and the solvent is water; after the dropwise addition is completed, the solution is stirred at a constant temperature of 60±3° C. for 2 hours, then air-cooled to room temperature, the pH is adjusted to neutral with 5 wt % hydrochloric acid, and the solution is concentrated under reduced pressure to 1 / 3 of the volume before concentration to obtain a promoter;

[0028] (4) preparing an aluminum nitrate solution, wherein the concentration of aluminum nitrate in the aluminum nitrate solution is 0.6 g / 100 mL, and the solvent is water; adding the modified seed crystals and the promoter to the aluminum nitrate solution to obtain a mixed solution; adding the modified seed crystals and the promoter to the aluminum nitrate solution in a ratio of aluminum nitrate solution: modified seed crystals: promoter = 100 mL: 1 g: 4 mL; stirring the mixed solution, and adding an ammonia aqueous solution to the mixed solution under stirring to adjust the pH of the mixed solution to 7, wherein the mass percentage of the solute in the ammonia aqueous solution is 25%; then stirring the mixed solution for 30 minutes, separating the solid and the liquid, washing the solid phase twice with deionized water, washing twice with ethanol, drying at 60°C, calcining the dried solid phase at 1300°C for 2 hours, and air cooling to room temperature to obtain the α-alumina catalyst carrier.

[0029] Example 3

[0030] A method for preparing a spherical α-alumina catalyst carrier comprises the following steps:

[0031] (1) Aluminum hydroxide powder is passed through a 1000-mesh sieve, and the sieved powder is collected. The sieved powder is mixed uniformly with an aqueous solution of polyethylene glycol (PEG-1000) in a reactor to obtain a mixture, wherein the mass percentage of polyethylene glycol in the aqueous solution of polyethylene glycol is 3%, and the solvent is water; the mass ratio of the sieved powder to the aqueous solution of polyethylene glycol is sieved powder: aqueous solution of polyethylene glycol = 10:4; the mixture is dried at 100°C for 30 minutes, and then air-cooled to room temperature, and an aqueous solution of urea is added to the reactor. liquid, lignin and aluminum fluoride, the mass ratio of the added urea aqueous solution, lignin and aluminum fluoride to the aluminum hydroxide in the mixture is urea aqueous solution: lignin: aluminum fluoride: aluminum hydroxide = 4:1:0.8:10; wherein the mass percentage of urea in the urea aqueous solution is 5%, and the solvent is water; after the addition is completed, the mixture is mixed evenly, dried at 100° C. for 30 minutes, then heated to 1200° C. in a muffle furnace and calcined for 20 hours, air-cooled to room temperature, ball-milled, and passed through a 1000-mesh sieve to obtain alumina seed crystals;

[0032] (2) preparing an acetic acid solution of chitosan, wherein the acetic acid solution of chitosan is prepared by mixing chitosan and acetic acid solution in a ratio of chitosan / acetic acid solution = 3 g / 100 mL, wherein the mass fraction of solute in the acetic acid solution is 2%; adding the alumina seed crystals to the acetic acid solution of chitosan to form a suspension, wherein the solid-liquid ratio of the alumina seed crystals to the acetic acid solution of chitosan to form a suspension is alumina seed crystals / chitosan acetic acid solution = 0.3 g:100 mL; the suspension is kept in a water bath at a constant temperature of 40±2° C., and then the suspension is stirred, and pentane is added to the suspension during the stirring process. An aqueous solution of dialdehyde, the mass ratio of the added mass of the aqueous solution of glutaraldehyde to the mass ratio of the alumina seeds in the suspension is alumina seeds: glutaraldehyde aqueous solution = 1:3, and the mass percentage of glutaraldehyde in the aqueous solution of glutaraldehyde is 17%; after the addition is completed, the suspension is stirred at a constant temperature of 40±2°C for 2h, and then the solid-liquid is separated, the solid phase is washed 3 times with acetic acid solution, and then washed 3 times with deionized water, and dried to obtain a dried solid phase; an aqueous solution of diethylenetriamine pentaacetic acid is prepared, the concentration of diethylenetriamine pentaacetic acid in the aqueous solution of diethylenetriamine pentaacetic acid is 200mg / 100mL, and stirred The aqueous solution of diethylenetriamine pentaacetic acid is added with 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide during stirring, and the amount ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide to the aqueous solution of diethylenetriamine pentaacetic acid is 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride: N-hydroxysuccinimide: aqueous solution of diethylenetriamine pentaacetic acid = 100 mg: 50 mg: 100 mL; after the addition is completed, the solution is stirred for 2 hours to obtain a modified solution; The modified liquid was kept at a constant temperature of 80±2°C in a water bath, and then the dried solid phase was added to the modified liquid to form a suspension, and the solid-liquid mass ratio of the dried solid phase to the modified liquid was solid / liquid = 1:80; the suspension was stirred at a constant temperature of 80±2°C for 30 minutes, and then diethylenetriamine was added to the suspension under stirring, and the added volume of diethylenetriamine was such that the volume ratio of diethylenetriamine to suspension was diethylenetriamine:suspension = 3mL:100mL; after the addition was completed, the mixture was continued to be stirred at a constant temperature of 80±2°C for 5 hours, and then air-cooled to room temperature, solid-liquid separation was performed, and the solid phase was washed 4 times with deionized water and dried to obtain modified seed crystals;

[0033] (3) preparing an aqueous solution of dodecyl glucoside, wherein the concentration of dodecyl glucoside in the aqueous solution is 12 g / 100 mL, and keeping the aqueous solution of dodecyl glucoside constant at 60±3° C. in a water bath, and then stirring the solution. During the stirring process, diethylene glycol diglycidyl ether and ethylene glycol are added to the aqueous solution of dodecyl glucoside. After the addition is completed, the solution is stirred at a constant temperature of 60±3° C. for 10 minutes, and then sodium hydroxide solution is added dropwise to the solution under stirring. Adding diethylene glycol diglycidyl ether, ethylene glycol, and sodium hydroxide solution to an aqueous solution in a ratio of dodecyl glucoside aqueous solution: diethylene glycol diglycidyl ether: ethylene glycol: sodium hydroxide solution = 100 mL: 11 g: 19 g: 7 mL, wherein the concentration of sodium hydroxide in the sodium hydroxide solution is 5 g / 100 mL, and the solvent is water; after the dropwise addition is completed, the solution is stirred at a constant temperature of 60±3° C. for 2 hours, then air-cooled to room temperature, the pH is adjusted to neutral with 5 wt % hydrochloric acid, and the solution is concentrated under reduced pressure to 1 / 3 of the volume before concentration to obtain a promoter;

[0034] (4) preparing an aluminum nitrate solution, wherein the concentration of aluminum nitrate in the aluminum nitrate solution is 0.6 g / 100 mL, and the solvent is water; adding the modified seed crystals and the promoter to the aluminum nitrate solution to obtain a mixed solution; adding the modified seed crystals and the promoter to the aluminum nitrate solution in a ratio of aluminum nitrate solution: modified seed crystals: promoter = 100 mL: 1.2 g: 4 mL; stirring the mixed solution, and adding an ammonia aqueous solution to the mixed solution under stirring to adjust the pH of the mixed solution to 7, wherein the mass percentage of the solute in the ammonia aqueous solution is 25%; then stirring the mixed solution for 30 minutes, separating the solid and the liquid, washing the solid phase twice with deionized water, washing twice with ethanol, drying at 60°C, calcining the dried solid phase at 1300°C for 2 hours, and air cooling to room temperature to obtain the α-alumina catalyst carrier.

[0035] Example 4

[0036] A method for preparing a spherical α-alumina catalyst carrier comprises the following steps:

[0037] (1) Aluminum hydroxide powder is passed through a 1000-mesh sieve, and the sieved powder is collected. The sieved powder is mixed uniformly with an aqueous solution of polyethylene glycol (PEG-1000) in a reactor to obtain a mixture, wherein the mass percentage of polyethylene glycol in the aqueous solution of polyethylene glycol is 3%, and the solvent is water; the mass ratio of the sieved powder to the aqueous solution of polyethylene glycol is sieved powder: aqueous solution of polyethylene glycol = 10:4; the mixture is dried at 100°C for 30 minutes, and then air-cooled to room temperature, and an aqueous solution of urea is added to the reactor. liquid, lignin and aluminum fluoride, the mass ratio of the added urea aqueous solution, lignin and aluminum fluoride to the aluminum hydroxide in the mixture is urea aqueous solution: lignin: aluminum fluoride: aluminum hydroxide = 4:1:0.9:10; wherein the mass percentage of urea in the urea aqueous solution is 5%, and the solvent is water; after the addition is completed, the mixture is mixed evenly, dried at 100° C. for 30 minutes, then heated to 1200° C. in a muffle furnace and calcined for 20 hours, air-cooled to room temperature, ball-milled, and passed through a 1000-mesh sieve to obtain alumina seed crystals;

[0038] (2) preparing an acetic acid solution of chitosan, wherein the acetic acid solution of chitosan is prepared by mixing chitosan and acetic acid solution in a ratio of chitosan / acetic acid solution = 3 g / 100 mL, wherein the mass fraction of solute in the acetic acid solution is 2%; adding the alumina seed crystals to the acetic acid solution of chitosan to form a suspension, wherein the solid-liquid ratio of the alumina seed crystals to the acetic acid solution of chitosan to form a suspension is alumina seed crystals / chitosan acetic acid solution = 0.3 g:100 mL; the suspension is kept in a water bath at a constant temperature of 40±2° C., and then the suspension is stirred, and pentane is added to the suspension during the stirring process. The mass ratio of the added mass of the aqueous solution of glutaraldehyde to the mass of the alumina seeds in the suspension is alumina seeds: glutaraldehyde aqueous solution = 1:3, and the mass percentage of glutaraldehyde in the aqueous solution of glutaraldehyde is 18%; after the addition is completed, the suspension is stirred at a constant temperature of 40±2°C for 2h, and then the solid-liquid is separated, the solid phase is washed 3 times with acetic acid solution, and then washed 3 times with deionized water, and dried to obtain a dried solid phase; an aqueous solution of diethylenetriamine pentaacetic acid is prepared, and the concentration of diethylenetriamine pentaacetic acid in the aqueous solution of diethylenetriamine pentaacetic acid is 200mg / 100mL, and stirred The aqueous solution of diethylenetriamine pentaacetic acid is added with 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide during stirring, and the amount ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide to the aqueous solution of diethylenetriamine pentaacetic acid is 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride: N-hydroxysuccinimide: aqueous solution of diethylenetriamine pentaacetic acid = 100 mg: 50 mg: 100 mL; after the addition is completed, the solution is stirred for 2 hours to obtain a modified solution; The modified liquid was kept at a constant temperature of 80±2°C in a water bath, and then the dried solid phase was added to the modified liquid to form a suspension, and the solid-liquid mass ratio of the dried solid phase to the modified liquid was solid / liquid = 1:80; the suspension was stirred at a constant temperature of 80±2°C for 30 minutes, and then diethylenetriamine was added to the suspension under stirring, and the added volume of the diethylenetriamine was the suspension volume ratio of diethylenetriamine:suspension = 4mL:100mL; after the addition was completed, the stirring was continued at a constant temperature of 80±2°C for 5 hours, and then air-cooled to room temperature, solid-liquid separation was carried out, and the solid phase was washed 4 times with deionized water and dried to obtain modified seed crystals;

[0039] (3) preparing an aqueous solution of dodecyl glucoside, wherein the concentration of dodecyl glucoside in the aqueous solution is 14 g / 100 mL, and keeping the aqueous solution of dodecyl glucoside constant at 60±3° C. in a water bath, and then stirring the solution. During the stirring process, diethylene glycol diglycidyl ether and ethylene glycol are added to the aqueous solution of dodecyl glucoside. After the addition is completed, the solution is stirred at a constant temperature of 60±3° C. for 10 minutes, and then sodium hydroxide solution is added dropwise to the solution under stirring to add the dodecyl glucoside solution. Adding diethylene glycol diglycidyl ether, ethylene glycol, and sodium hydroxide solution to an aqueous solution in a ratio of dodecyl glucoside aqueous solution: diethylene glycol diglycidyl ether: ethylene glycol: sodium hydroxide solution = 100 mL: 12 g: 20 g: 9 mL, wherein the concentration of sodium hydroxide in the sodium hydroxide solution is 5 g / 100 mL, and the solvent is water; after the dropwise addition is completed, the solution is stirred at a constant temperature of 60±3° C. for 2 hours, then air-cooled to room temperature, the pH is adjusted to neutral with 5 wt % hydrochloric acid, and concentrated under reduced pressure to 1 / 3 of the volume before concentration to obtain a promoter;

[0040] (4) preparing an aluminum nitrate solution, wherein the concentration of aluminum nitrate in the aluminum nitrate solution is 0.6 g / 100 mL, and the solvent is water; adding the modified seed crystals and the promoter to the aluminum nitrate solution to obtain a mixed solution; adding the modified seed crystals and the promoter to the aluminum nitrate solution in a ratio of aluminum nitrate solution: modified seed crystals: promoter = 100 mL: 1.4 g: 5 mL; stirring the mixed solution, adding an ammonia aqueous solution to the mixed solution under stirring to adjust the pH of the mixed solution to 7, wherein the mass percentage of the solute in the ammonia aqueous solution is 25%; then stirring the mixed solution for 30 minutes, separating the solid and the liquid, washing the solid phase twice with deionized water, washing twice with ethanol, drying at 60°C, calcining the dried solid phase at 1300°C for 2 hours, and air cooling to room temperature to obtain the α-alumina catalyst carrier.

[0041] Comparative Example 1

[0042] A comparative preparation method for a catalyst support comprises the following steps: preparing an aluminum nitrate solution, wherein the concentration of aluminum nitrate in the aluminum nitrate solution is 0.6 g / 100 mL, and the solvent is water; adding an ammonia solution to the aluminum nitrate solution under stirring to adjust the pH of the solution to 7, wherein the mass percentage of the solute in the ammonia solution is 25%; then stirring the solution for 30 minutes, separating the solid and the liquid, washing the solid phase twice with deionized water and then twice with ethanol, drying at 60° C., calcining the dried solid phase at 1300° C. for 2 hours, and air cooling to room temperature to obtain the catalyst support described in this comparative example.

[0043] Comparative Example 2

[0044] A comparative method for preparing a catalyst support comprises the following steps:

[0045] (1) Aluminum hydroxide powder is passed through a 1000-mesh sieve, and the sieved powder is collected. The sieved powder is mixed uniformly with an aqueous solution of polyethylene glycol (PEG-1000) in a reactor to obtain a mixture, wherein the mass percentage of polyethylene glycol in the aqueous solution of polyethylene glycol is 3%, and the solvent is water; the mass ratio of the sieved powder to the aqueous solution of polyethylene glycol is sieved powder: aqueous solution of polyethylene glycol = 10:4; the mixture is dried at 100°C for 30 minutes, and then air-cooled to room temperature, and an aqueous solution of urea is added to the reactor. liquid, lignin and aluminum fluoride, the mass ratio of the added urea aqueous solution, lignin and aluminum fluoride to the aluminum hydroxide in the mixture is urea aqueous solution: lignin: aluminum fluoride: aluminum hydroxide = 3:1:0.7:10; wherein the mass percentage of urea in the urea aqueous solution is 5%, and the solvent is water; after the addition is completed, the mixture is mixed evenly, dried at 100° C. for 30 minutes, then heated to 1200° C. in a muffle furnace and calcined for 20 hours, air-cooled to room temperature, ball-milled, and passed through a 1000-mesh sieve to obtain alumina seed crystals;

[0046] (2) preparing an aqueous solution of dodecyl glucoside, wherein the concentration of dodecyl glucoside in the aqueous solution is 12 g / 100 mL, and keeping the aqueous solution of dodecyl glucoside constant at 60±3° C. in a water bath, and then stirring the solution. During the stirring process, diethylene glycol diglycidyl ether and ethylene glycol are added to the aqueous solution of dodecyl glucoside. After the addition is completed, the solution is stirred at a constant temperature of 60±3° C. for 10 minutes, and then sodium hydroxide solution is added dropwise to the solution under stirring. Adding diethylene glycol diglycidyl ether, ethylene glycol, and sodium hydroxide solution to an aqueous solution in a ratio of dodecyl glucoside aqueous solution: diethylene glycol diglycidyl ether: ethylene glycol: sodium hydroxide solution = 100 mL: 11 g: 19 g: 7 mL, wherein the concentration of sodium hydroxide in the sodium hydroxide solution is 4 g / 100 mL, and the solvent is water; after the dropwise addition is completed, the solution is stirred at a constant temperature of 60±3° C. for 2 hours, then air-cooled to room temperature, the pH is adjusted to neutral with 5 wt % hydrochloric acid, and the solution is concentrated under reduced pressure to 1 / 3 of the volume before concentration to obtain a promoter;

[0047] (3) preparing an aluminum nitrate solution, wherein the concentration of aluminum nitrate in the aluminum nitrate solution is 0.6 g / 100 mL, and the solvent is water; adding the aluminum oxide seeds and the promoter to the aluminum nitrate solution to obtain a mixed solution; adding the aluminum oxide seeds and the promoter to the aluminum nitrate solution in a ratio of aluminum nitrate solution: aluminum oxide seeds: promoter = 100 mL: 1 g: 4 mL; stirring the mixed solution, and adding an ammonia aqueous solution to the mixed solution while stirring to adjust the pH of the mixed solution to 7, wherein the mass percentage of the solute in the ammonia aqueous solution is 25%; then stirring the mixed solution for 30 minutes, separating the solid and the liquid, washing the solid phase twice with deionized water, washing twice with ethanol, drying at 60°C, calcining the dried solid phase at 1300°C for 2 hours, and air-cooling to room temperature to obtain the catalyst support described in this comparative example.

[0048] Comparative Example 3

[0049] A comparative method for preparing a catalyst support comprises the following steps:

[0050] (1) Aluminum hydroxide powder is passed through a 1000-mesh sieve, and the sieved powder is collected. The sieved powder is mixed uniformly with an aqueous solution of polyethylene glycol (PEG-1000) in a reactor to obtain a mixture, wherein the mass percentage of polyethylene glycol in the aqueous solution of polyethylene glycol is 3%, and the solvent is water; the mass ratio of the sieved powder to the aqueous solution of polyethylene glycol is sieved powder: aqueous solution of polyethylene glycol = 10:4; the mixture is dried at 100°C for 30 minutes, and then air-cooled to room temperature, and an aqueous solution of urea is added to the reactor. liquid, lignin and aluminum fluoride, the mass ratio of the added urea aqueous solution, lignin and aluminum fluoride to the aluminum hydroxide in the mixture is urea aqueous solution: lignin: aluminum fluoride: aluminum hydroxide = 3:1:0.7:10; wherein the mass percentage of urea in the urea aqueous solution is 5%, and the solvent is water; after the addition is completed, the mixture is mixed evenly, dried at 100° C. for 30 minutes, then heated to 1200° C. in a muffle furnace and calcined for 20 hours, air-cooled to room temperature, ball-milled, and passed through a 1000-mesh sieve to obtain alumina seed crystals;

[0051] (2) preparing an acetic acid solution of chitosan, wherein the acetic acid solution of chitosan is prepared by mixing chitosan and acetic acid solution in a ratio of chitosan / acetic acid solution = 2 g / 100 mL, wherein the mass fraction of solute in the acetic acid solution is 2%; adding the alumina seed crystals to the acetic acid solution of chitosan to form a suspension, wherein the solid-liquid ratio of the alumina seed crystals to the acetic acid solution of chitosan to form a suspension is alumina seed crystals / chitosan acetic acid solution = 0.2 g:100 mL; and keeping the suspension in a water bath at a constant temperature of 40±2°C. The suspension was then stirred, and an aqueous solution of glutaraldehyde was added to the suspension during the stirring process. The mass ratio of the added aqueous solution of glutaraldehyde to the alumina seeds in the suspension was alumina seeds: glutaraldehyde aqueous solution = 1:2, and the mass percentage of glutaraldehyde in the aqueous solution of glutaraldehyde was 16%. After the addition was completed, the suspension was continued to be stirred at a constant temperature of 40±2° C. for 2 h, followed by solid-liquid separation, and the solid phase was washed three times with an acetic acid solution and then washed three times with deionized water, and dried to obtain a dried solid phase, which was used as the modified seed crystals of this comparative example.

[0052] (3) preparing an aqueous solution of dodecyl glucoside, wherein the concentration of dodecyl glucoside in the aqueous solution is 12 g / 100 mL, and keeping the aqueous solution of dodecyl glucoside constant at 60±3° C. in a water bath, and then stirring the solution. During the stirring process, diethylene glycol diglycidyl ether and ethylene glycol are added to the aqueous solution of dodecyl glucoside. After the addition is completed, the solution is stirred at a constant temperature of 60±3° C. for 10 minutes, and then sodium hydroxide solution is added dropwise to the solution under stirring. Adding diethylene glycol diglycidyl ether, ethylene glycol, and sodium hydroxide solution to an aqueous solution in a ratio of dodecyl glucoside aqueous solution: diethylene glycol diglycidyl ether: ethylene glycol: sodium hydroxide solution = 100 mL: 11 g: 19 g: 7 mL, wherein the concentration of sodium hydroxide in the sodium hydroxide solution is 4 g / 100 mL, and the solvent is water; after the dropwise addition is completed, the solution is stirred at a constant temperature of 60±3° C. for 2 hours, then air-cooled to room temperature, the pH is adjusted to neutral with 5 wt % hydrochloric acid, and the solution is concentrated under reduced pressure to 1 / 3 of the volume before concentration to obtain a promoter;

[0053] (4) preparing an aluminum nitrate solution, wherein the concentration of aluminum nitrate in the aluminum nitrate solution is 0.6 g / 100 mL, and the solvent is water; adding the modified seed crystals and the promoter to the aluminum nitrate solution to obtain a mixed solution; adding the modified seed crystals and the promoter to the aluminum nitrate solution in a ratio of aluminum nitrate solution: modified seed crystals: promoter = 100 mL: 1 g: 4 mL; stirring the mixed solution, and adding an ammonia aqueous solution to the mixed solution under stirring to adjust the pH of the mixed solution to 7, wherein the mass percentage of the solute in the ammonia aqueous solution is 25%; then stirring the mixed solution for 30 minutes, separating the solid and the liquid, washing the solid phase twice with deionized water, washing twice with ethanol, drying at 60°C, calcining the dried solid phase at 1300°C for 2 hours, and air-cooling to room temperature to obtain the catalyst support described in this comparative example.

[0054] Comparative Example 4

[0055] A comparative method for preparing a catalyst support comprises the following steps:

[0056] (1) Aluminum hydroxide powder is passed through a 1000-mesh sieve, and the sieved powder is collected. The sieved powder is mixed uniformly with an aqueous solution of polyethylene glycol (PEG-1000) in a reactor to obtain a mixture, wherein the mass percentage of polyethylene glycol in the aqueous solution of polyethylene glycol is 3%, and the solvent is water; the mass ratio of the sieved powder to the aqueous solution of polyethylene glycol is sieved powder: aqueous solution of polyethylene glycol = 10:4; the mixture is dried at 100°C for 30 minutes, and then air-cooled to room temperature, and an aqueous solution of urea is added to the reactor. liquid, lignin and aluminum fluoride, the mass ratio of the added urea aqueous solution, lignin and aluminum fluoride to the aluminum hydroxide in the mixture is urea aqueous solution: lignin: aluminum fluoride: aluminum hydroxide = 3:1:0.7:10; wherein the mass percentage of urea in the urea aqueous solution is 5%, and the solvent is water; after the addition is completed, the mixture is mixed evenly, dried at 100° C. for 30 minutes, then heated to 1200° C. in a muffle furnace and calcined for 20 hours, air-cooled to room temperature, ball-milled, and passed through a 1000-mesh sieve to obtain alumina seed crystals;

[0057] (2) preparing an acetic acid solution of chitosan, wherein the acetic acid solution of chitosan is prepared by mixing chitosan and acetic acid solution in a ratio of chitosan / acetic acid solution = 2 g / 100 mL, wherein the mass fraction of solute in the acetic acid solution is 2%; adding the alumina seed crystals to the acetic acid solution of chitosan to form a suspension, wherein the solid-liquid ratio of the alumina seed crystals to the acetic acid solution of chitosan to form a suspension is alumina seed crystals / chitosan acetic acid solution = 0.2 g:100 mL; the suspension is kept in a water bath at a constant temperature of 40±2° C., and then the suspension is stirred, and pentane is added to the suspension during the stirring process. The mass ratio of the added mass of the aqueous solution of glutaraldehyde to the mass of the alumina seeds in the suspension is alumina seeds: glutaraldehyde aqueous solution = 1:2, and the mass percentage of glutaraldehyde in the aqueous solution of glutaraldehyde is 16%; after the addition is completed, the suspension is stirred at a constant temperature of 40±2°C for 2h, and then the solid-liquid is separated, the solid phase is washed 3 times with acetic acid solution, and then washed 3 times with deionized water, and dried to obtain a dried solid phase; an aqueous solution of diethylenetriamine pentaacetic acid is prepared, and the concentration of diethylenetriamine pentaacetic acid in the aqueous solution of diethylenetriamine pentaacetic acid is 180mg / 100mL, and stirred The aqueous solution of diethylenetriamine pentaacetic acid is added with 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide during stirring, and the amount ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide to the aqueous solution of diethylenetriamine pentaacetic acid is 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride: N-hydroxysuccinimide: aqueous solution of diethylenetriamine pentaacetic acid = 90 mg: 40 mg: 100 mL; after the addition is completed, the solution is stirred for 2 hours to obtain a modified solution; the modified solution is added with 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide in a ratio of 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride: N-hydroxysuccinimide: aqueous solution of diethylenetriamine pentaacetic acid = 90 mg: 40 mg: 100 mL; after the addition is completed, the solution is stirred for 2 hours to obtain a modified solution; The modified liquid is kept at a constant temperature of 80±2° C. in a water bath, and then the dried solid phase is added to the modified liquid to form a suspension, and the solid-liquid mass ratio of the dried solid phase to the modified liquid is solid / liquid=1:80; the suspension is stirred at a constant temperature of 80±2° C. for 30 minutes, and then diethylenetriamine is added to the suspension under stirring, and the added volume of the diethylenetriamine is the suspension volume ratio of diethylenetriamine:suspension=3mL:100mL; after the addition is completed, the mixture is continued to be stirred at a constant temperature of 80±2° C. for 5 hours, and then air-cooled to room temperature, solid-liquid separation is carried out, and the solid phase is washed 4 times with deionized water and dried to obtain modified seed crystals;

[0058] (3) preparing an aqueous solution of dodecyl glucoside as the accelerator of this comparative example, wherein the concentration of dodecyl glucoside in the aqueous solution is 12 g / 100 mL;

[0059] (4) preparing an aluminum nitrate solution, wherein the concentration of aluminum nitrate in the aluminum nitrate solution is 0.6 g / 100 mL, and the solvent is water; adding the modified seed crystals and the promoter to the aluminum nitrate solution to obtain a mixed solution; adding the modified seed crystals and the promoter to the aluminum nitrate solution in a ratio of aluminum nitrate solution: modified seed crystals: promoter = 100 mL: 1 g: 4 mL; stirring the mixed solution, and adding an ammonia aqueous solution to the mixed solution under stirring to adjust the pH of the mixed solution to 7, wherein the mass percentage of the solute in the ammonia aqueous solution is 25%; then stirring the mixed solution for 30 minutes, separating the solid and the liquid, washing the solid phase twice with deionized water, washing twice with ethanol, drying at 60°C, calcining the dried solid phase at 1300°C for 2 hours, and air-cooling to room temperature to obtain the catalyst support described in this comparative example.

[0060] Example 5

[0061] The specific surface areas of the α-alumina catalyst supports prepared by the methods described in the above examples and comparative examples were tested, and the results are shown in Table 1.

[0062] Table 1

[0063] experimental group <![CDATA[Specific surface area (m 2 / g)]]> Example 1 19.8 Example 2 21.7 Example 3 20.9 Example 4 20.6 Comparative Example 1 11.3 Comparative Example 2 12.9 Comparative Example 3 13.4 Comparative Example 4 15.0

[0064] As can be seen from Table 1, the α-alumina catalyst carrier prepared by the method of the present invention has a large specific surface area, which can be used to attach more catalytic active ingredients, increase the specific surface area of ​​the catalytic active ingredients, and increase the number of catalytic active sites.

[0065] The technical solutions provided by the present invention are described in detail above. For those skilled in the art, according to the ideas of the embodiments of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A method for preparing a spherical α-alumina catalyst carrier, characterized in that: The steps include: (1) passing aluminum hydroxide powder through a 1000-mesh sieve, collecting the sieved powder, and uniformly mixing the sieved powder with an aqueous solution of polyethylene glycol in a reactor to obtain a mixture, drying the mixture at 100° C. for 30 to 40 minutes, and then air-cooling it to room temperature. Adding an aqueous solution of urea, lignin, and aluminum fluoride to the reactor, uniformly mixing the mixture after the addition is completed, and then drying it at 100° C. for 30 to 40 minutes. Then, heating it to 1200° C. in a muffle furnace and calcining it for more than 20 hours, air-cooling it to room temperature, ball-milling it, and passing it through a 1000-mesh sieve to obtain aluminum oxide seed crystals; (2) preparing an acetic acid solution of chitosan, adding the alumina seed crystals to the acetic acid solution of chitosan to form a suspension, keeping the suspension constant at 40±2°C in a water bath, and then stirring the suspension. During the stirring process, an aqueous solution of glutaraldehyde is added to the suspension. After the addition is completed, the suspension is continuously stirred at a constant temperature of 40±2°C for more than 2 hours, and then the solid-liquid separation is carried out. The solid phase is washed with acetic acid solution for more than 3 times, and then washed with deionized water for more than 3 times, and dried to obtain a dried solid phase; preparing an aqueous solution of diethylenetriamine pentaacetic acid, stirring the aqueous solution of diethylenetriamine pentaacetic acid, adding 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide to the solution during the stirring process, and continuing to stir the solution for more than 2 hours after the addition is completed to obtain a modified solution; The modified liquid is kept at a constant temperature of 80±2°C in a water bath, and then the dried solid phase is added to the modified liquid to form a suspension. The suspension is stirred at a constant temperature of 80±2°C for more than 30 minutes, and then diethylenetriamine is added to the suspension under stirring. After the addition is completed, the constant temperature stirring is continued at 80±2°C for more than 5 hours, and then air-cooled to room temperature, the solid and liquid are separated, the solid phase is washed with deionized water for more than 4 times, and dried to obtain modified seed crystals; (3) preparing an aqueous solution of dodecyl glucoside, keeping the aqueous solution of dodecyl glucoside constant temperature at 60±3°C in a water bath, and then stirring the solution. During the stirring process, diethylene glycol diglycidyl ether and ethylene glycol are added to the aqueous solution of dodecyl glucoside. After the addition is completed, the solution is stirred at a constant temperature of 60±3°C for more than 10 minutes. Then, sodium hydroxide solution is added dropwise to the solution under stirring. After the addition is completed, the solution is stirred at a constant temperature of 60±3°C for 2-3 hours. Then, the solution is air-cooled to room temperature, the pH is adjusted to neutral with 5wt% hydrochloric acid, and the solution is concentrated under reduced pressure to obtain a promoter. (4) preparing an aluminum nitrate solution, and adding the modified seed crystal and the promoter to the aluminum nitrate solution to obtain a mixed solution; The mixed liquid is stirred, and an ammonia solution is added to the mixed liquid under stirring to adjust the pH of the mixed liquid to 7, and then the mixed liquid is stirred for more than 30 minutes, and the solid-liquid separation is carried out. The solid phase is washed with deionized water for more than 2 times, and then washed with ethanol for more than 2 times, and dried at 60°C. The dried solid phase is calcined at a temperature of 1300-1340°C for 2 hours, and air-cooled to room temperature to obtain the α-alumina catalyst carrier.

2. The method for preparing a spherical α-alumina catalyst carrier according to claim 1, characterized in that: In the step (1), the mass percentage of polyethylene glycol in the polyethylene glycol aqueous solution is 3% to 5%, and the solvent is water; the mass ratio of the sieved powder to the polyethylene glycol aqueous solution is sieved powder: polyethylene glycol aqueous solution = 10:4-5.

3. The method for preparing a spherical α-alumina catalyst carrier according to claim 1, characterized in that: In the step (1), the mass ratio of the added urea aqueous solution, lignin and aluminum fluoride to the aluminum hydroxide in the mixture is urea aqueous solution: lignin: aluminum fluoride: aluminum hydroxide = 3-4:1:0.6-0.9:10; wherein the mass percentage of urea in the urea aqueous solution is 5%, and the solvent is water.

4. The method for preparing a spherical α-alumina catalyst carrier according to claim 1, characterized in that: In the step (2), the chitosan acetic acid solution is prepared by mixing chitosan and acetic acid solution in a ratio of chitosan / acetic acid solution = 2-3 g / 100 mL, and the mass fraction of the solute in the acetic acid solution is 2%; the alumina seeds are added to the chitosan acetic acid solution to form a suspension in a solid-liquid ratio of alumina seeds / chitosan acetic acid solution = 0.2-0.3 g:100 mL; the mass ratio of the added glutaraldehyde aqueous solution to the alumina seeds in the suspension is alumina seeds: glutaraldehyde aqueous solution = 1:2-3, and the mass percentage of glutaraldehyde in the glutaraldehyde aqueous solution is 15%-18%.

5. The method for preparing a spherical α-alumina catalyst carrier according to claim 1, characterized in that: In the step (2), the concentration of diethylenetriamine pentaacetic acid in the aqueous solution is 150-200 mg / 100 mL, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide are added to the aqueous solution of diethylenetriamine pentaacetic acid in a ratio of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride:N-hydroxysuccinimide:diethylenetriamine pentaacetic acid aqueous solution = 90-100 mg:40-50 mg:100 mL; the dried solid phase is added to the modified liquid in a solid-liquid mass ratio of solid / liquid = 1:80; the added volume of the diethylenetriamine is the suspension volume ratio of diethylenetriamine:suspension = 2-4 mL:100 mL.

6. The method for preparing a spherical α-alumina catalyst carrier according to claim 1, characterized in that: In the step (3), the concentration of dodecyl glucoside in the aqueous solution is 10-14 g / 100 mL, and diethylene glycol diglycidyl ether, ethylene glycol and sodium hydroxide solution are added to the aqueous solution of dodecyl glucoside in a ratio of dodecyl glucoside aqueous solution: diethylene glycol diglycidyl ether: ethylene glycol: sodium hydroxide solution = 100 mL: 10-12 g: 18-20 g: 4-9 mL. The concentration of sodium hydroxide in the sodium hydroxide solution is 4-5 g / 100 mL, and the solvent is water.

7. The method for preparing a spherical α-alumina catalyst carrier according to claim 1, characterized in that: In the step (4), the concentration of aluminum nitrate in the aluminum nitrate solution is 0.5-0.7 g / 100 mL, and the solvent is water; the modified seed crystals and the promoter are added to the aluminum nitrate solution in a ratio of aluminum nitrate solution: modified seed crystals: promoter = 100 mL: 0.8-1.4 g: 3-5 mL.

8. The method for preparing a spherical α-alumina catalyst carrier according to claim 1, characterized in that: In the step (4), the mass percentage of the solute in the ammonia solution is 25%.