Antimony catalyst and application thereof in flue gas denitration
By optimizing the pore structure and activity of antimony-based catalysts through plasma treatment and acid-base etching, combined with modification treatment, a physical coating barrier is formed, which solves the problems of insufficient activity and sulfur poisoning of antimony-based catalysts in the low-temperature range, and achieves efficient flue gas denitrification.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-23
- Publication Date
- 2026-03-13
AI Technical Summary
Existing antimony-based catalysts have insufficient activity in the low-temperature range, low conversion rate, and are susceptible to sulfur poisoning and water inhibition. The utilization rate of active sites on the catalyst surface is not high, which leads to the degradation of denitrification performance and limits their industrial application.
Plasma treatment was used to activate the antimony catalyst, which was then etched with acid and alkali solutions to introduce active functional groups. Citric acid and polyaspartic acid were used to modify the catalyst, forming a physical coating barrier to enhance its resistance to sulfur poisoning and optimize its pore structure and reactivity.
It significantly improved the low-temperature denitrification activity, enhanced the catalyst's resistance to sulfur poisoning, extended its service life, and improved the flue gas denitrification effect.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of catalysis technology, specifically to an antimony-based catalyst and its application in flue gas denitrification. Background Technology
[0002] Nitrogen oxides (NOx) are among the major air pollutants, and their emissions trigger a series of environmental problems such as acid rain, photochemical smog, and ozone depletion, seriously threatening the ecological environment and human health. Selective catalytic reduction (SCR) is currently the most widely used and technologically mature process for industrial flue gas denitrification. Its core principle is to use a catalyst to selectively react with NOx at a specific temperature. x The reaction produces non-toxic and harmless N2 and H2O.
[0003] Antimony (Sb)-based catalysts (mainly their oxides) are environmentally friendly non-vanadium-based catalyst materials, showing potential application prospects in denitrification due to their unique acidic sites and redox properties. However, existing antimony-based catalysts still suffer from poor denitrification performance in practical industrial applications, mainly manifested in: insufficient activity and low conversion rates in the low-temperature range (<200℃); susceptibility to sulfur poisoning and water inhibition under complex flue gas conditions containing sulfur and water, leading to rapid degradation of denitrification performance; and a limited number and low utilization rate of active sites on the catalyst surface, thus limiting the catalytic reaction rate. These problems severely restrict the industrial application of antimony-based catalysts.
[0004] Therefore, this application is submitted. Summary of the Invention
[0005] This invention provides an antimony-based catalyst and its application in flue gas denitrification, wherein the antimony-based catalyst has excellent flue gas denitrification effect.
[0006] The present invention solves its technical problem by adopting the following technical solution: A method for preparing an antimony-based catalyst, characterized by comprising the following steps: (1) The antimony-containing catalyst is subjected to plasma treatment to obtain an activated catalyst; (2) The activated catalyst is first etched with acid solution, then etched with alkaline solution, washed with water until neutral, and dried to obtain the etched catalyst; (3) Add the etching catalyst, citric acid and polyaspartic acid to the modification solution, sonicate at 80~90℃ for 60~100min, filter and dry to obtain the modified catalyst; (4) The modified catalyst is added to the coating solution, filtered, dried, and then subjected to the first heat treatment, the second heat treatment, and the third heat treatment in sequence to obtain the antimony catalyst.
[0007] This application first activates the antimony-containing catalyst with plasma to introduce active functional groups and improve surface reactivity. Then, it is etched sequentially with acid and alkali solutions to effectively control the pore structure of the catalyst and further improve its reactivity. Next, it is treated with citric acid, polyaspartic acid, and a modifying solution to ensure that the modified components penetrate evenly into the pores and improve the loading stability. Finally, it is coated to form a physical coating barrier, which effectively blocks the diffusion of SO2 and H2O molecules into the catalyst interior and inhibits the formation and deposition of sulfates. Combined with the adsorption competition of the active groups introduced by plasma activation on sulfur species, the anti-sulfur poisoning performance is significantly improved, and the denitrification effect of flue gas is effectively improved.
[0008] As an embodiment of this application, the antimony-containing catalyst comprises the following components by mass percentage: 10-20% graphene aerogel, 15-20% dioxane pentoxide, 2-5% antimony acetate, 1-3% silicon carbide, 0.5-1% lanthanum oxide, and the balance titanium dioxide.
[0009] The preparation method of this application targets the aforementioned specific antimony-containing catalyst, taking advantage of the high porosity of three-dimensional graphene aerogel. Plasma activation and acid / alkali etching are used to regulate the pore structure. Targeting the redox properties of the antimony pentoxide and antimony acetate composite active components, complexation, dispersion, and elemental doping modification liquids are employed to enhance the redox cycle. The low-temperature denitrification activity is significantly improved, ensuring that the modified components uniformly penetrate deep into the pores of the carrier. The oxide (silicon oxide, aluminum oxide) composite coating layer can form a uniform and dense protective barrier on the catalyst surface, inhibiting the formation and deposition of sulfate, effectively extending the catalyst's service life, and effectively improving the flue gas denitrification effect.
[0010] As an embodiment of this application, the plasma treatment uses a mixture of argon and oxygen as the discharge gas, with a flow rate of 20~30 sccm, a power of 300~600W, and a time of 20~40 min. The volume ratio of argon to oxygen is (3~5):1.
[0011] As an embodiment of this application, the acid solution is a nitric acid solution with a mass fraction of 2-10%, the solid-liquid ratio of the acid etching is 1g:(4-10)mL, and the acid etching time is 30-60min; The alkaline solution is an ammonia solution with a mass fraction of 2-10%, the solid-liquid ratio of the alkaline etching solution is 1g:(4-10)mL, and the etching time is 30-60min.
[0012] As an embodiment of this application, the mass ratio of the etching catalyst, citric acid, polyaspartic acid, and modifying liquid is 1:(0.01~0.02):(0.02~0.05):(4~10).
[0013] As an embodiment of this application, the modified solution is a mixed solution containing cerium nitrate and zirconium nitrate, wherein the molar concentration of cerium nitrate in the mixed solution is 0.1~0.5 mol / L and the molar concentration of zirconium nitrate is 0.1~0.5 mol / L.
[0014] As an embodiment of this application, the coating solution is prepared by mixing tetraethyl orthosilicate and aluminum isopropoxide in a mass ratio of (2~3):1, adding hydrochloric acid solution to adjust the pH to 2~3, and obtaining the coating solution.
[0015] As an embodiment of this application, the temperature of the first heat treatment is 200~250℃, and the time is 1~2h; The second heat treatment is performed at a temperature of 350~400℃ for 1.5~3 hours. The third heat treatment is performed at a temperature of 450-500℃ for 2-4 hours.
[0016] As an embodiment of this application, the power of the ultrasonic treatment is 200~600W and the time is 20~60min.
[0017] The present invention also provides an antimony catalyst, which is prepared by the preparation method described above.
[0018] This invention also provides an application of antimony-based catalysts in flue gas denitrification.
[0019] The beneficial effects of this invention are as follows: First, the antimony-containing catalyst is activated by plasma to introduce active functional groups and improve surface reactivity. Then, it is etched sequentially with acid and alkali solutions to effectively control the pore structure of the catalyst and further improve its reactivity. Then, it is treated with citric acid, polyaspartic acid, and a modifying solution to ensure that the modified components penetrate evenly into the pores and improve the loading stability. Finally, it is coated to form a physical coating barrier, which effectively improves the denitrification effect of flue gas. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0021] In this invention, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions that include the listed features.
[0022] In this invention, numerical ranges are involved. Unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values of the range. Additionally, when multiple ranges are provided to describe features or characteristics, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included.
[0023] In this invention, there are no particular limitations on the specific dispersion and stirring methods.
[0024] Unless otherwise specified, all reagents or instruments used in this invention are commercially available conventional products. Unless otherwise specified, the raw materials used in each comparative example and the parallel experiments of each embodiment are the same commercially available products.
[0025] Example 1 A method for preparing an antimony-based catalyst includes the following steps: (1) Weigh the following components according to the mass percentage: 16% graphene aerogel, 18% dithionite pentoxide, 4% antimony acetate, 1.2% silicon carbide, 0.8% lanthanum oxide, and the balance titanium dioxide (anatase type). Ball mill and mix the components evenly to obtain an antimony-containing catalyst.
[0026] (2) The antimony-containing catalyst is placed in a plasma treatment device and subjected to plasma treatment to obtain an activated catalyst; The plasma treatment uses a mixture of argon and oxygen as the discharge gas, with a flow rate of 28 sccm, a power of 500 W, and a time of 30 min; the volume ratio of argon to oxygen is 4:1.
[0027] (3) The activated catalyst was placed in an 8% nitric acid solution at a solid-liquid ratio of 1g:8mL and immersed and etched at 55℃ for 50min; The activated catalyst was then placed in a 5% ammonia solution at a solid-liquid ratio of 1g:8mL and immersed and etched at 45°C for 50min; washed with water until neutral and dried to obtain the etching catalyst. (4) Add cerium nitrate and zirconium nitrate to water to prepare a modified solution with a molar concentration of cerium nitrate of 0.2 mol / L and a molar concentration of zirconium nitrate of 0.2 mol / L; Etching catalyst, citric acid, and polyaspartic acid were added to the modification solution, ultrasonically treated at 85°C for 80 min, filtered, and dried to obtain the modified catalyst. The mass ratio of the etching catalyst, citric acid, polyaspartic acid, and modifying solution is 1:0.01:0.05:8.
[0028] (5) Mix tetraethyl orthosilicate and aluminum isopropoxide at a mass ratio of 2:1, add hydrochloric acid solution to adjust the pH to 2.8, and obtain the coating solution.
[0029] The modified catalyst was added to the coating solution and stirred at 200 rpm for 1 hour at 45°C. The mixture was then filtered and dried.
[0030] The dried material was added to a tube furnace and heated to 250°C at 5°C / min under air atmosphere, and held for 1 hour; then heated to 400°C at 5°C / min, and held for 1.5 hours; then heated to 500°C at 5°C / min, and held for 2 hours to obtain an antimony catalyst.
[0031] Example 2 A method for preparing an antimony-based catalyst includes the following steps: (1) Weigh the following components according to the mass percentage: 10% graphene aerogel, 20% dioxane pentoxide, 2% antimony acetate, 3% silicon carbide, 0.5% lanthanum oxide, and the balance titanium dioxide (anatase type). Ball mill and mix the components evenly to obtain an antimony-containing catalyst.
[0032] (2) The antimony-containing catalyst is placed in a plasma treatment device and subjected to plasma treatment to obtain an activated catalyst; The plasma treatment uses a mixture of argon and oxygen as the discharge gas, with a flow rate of 28 sccm, a power of 500 W, and a time of 30 min; the volume ratio of argon to oxygen is 4:1.
[0033] (3) The activated catalyst was placed in an 8% nitric acid solution at a solid-liquid ratio of 1g:8mL and immersed and etched at 55℃ for 50min; The activated catalyst was then placed in a 5% ammonia solution at a solid-liquid ratio of 1g:8mL and immersed and etched at 45°C for 50min; washed with water until neutral and dried to obtain the etching catalyst. (4) Add cerium nitrate and zirconium nitrate to water to prepare a modified solution with a molar concentration of cerium nitrate of 0.2 mol / L and a molar concentration of zirconium nitrate of 0.2 mol / L; Etching catalyst, citric acid, and polyaspartic acid were added to the modification solution, ultrasonically treated at 85°C for 80 min, filtered, and dried to obtain the modified catalyst. The mass ratio of the etching catalyst, citric acid, polyaspartic acid, and modifying solution is 1:0.01:0.05:8.
[0034] (5) Mix tetraethyl orthosilicate and aluminum isopropoxide at a mass ratio of 2:1, add hydrochloric acid solution to adjust the pH to 2.8, and obtain the coating solution.
[0035] The modified catalyst was added to the coating solution and stirred at 200 rpm for 1 hour at 45°C. The mixture was then filtered and dried.
[0036] The dried material was added to a tube furnace and heated to 250°C at 5°C / min under air atmosphere, and held for 1 hour; then heated to 400°C at 5°C / min, and held for 1.5 hours; then heated to 500°C at 5°C / min, and held for 2 hours to obtain an antimony catalyst.
[0037] Example 3 A method for preparing an antimony-based catalyst includes the following steps: (1) Weigh the following components according to the mass percentage: 20% graphene aerogel, 15% dioxane pentoxide, 5% antimony acetate, 1% silicon carbide, 1% lanthanum oxide, and the balance titanium dioxide (anatase type). Ball mill and mix the components evenly to obtain an antimony-containing catalyst.
[0038] (2) The antimony-containing catalyst is placed in a plasma treatment device and subjected to plasma treatment to obtain an activated catalyst; The plasma treatment uses a mixture of argon and oxygen as the discharge gas, with a flow rate of 28 sccm, a power of 500 W, and a time of 30 min; the volume ratio of argon to oxygen is 4:1.
[0039] (3) The activated catalyst was placed in an 8% nitric acid solution at a solid-liquid ratio of 1g:8mL and immersed and etched at 55℃ for 50min; The activated catalyst was then placed in a 5% ammonia solution at a solid-liquid ratio of 1g:8mL and immersed and etched at 45°C for 50min; washed with water until neutral and dried to obtain the etching catalyst. (4) Add cerium nitrate and zirconium nitrate to water to prepare a modified solution with a molar concentration of cerium nitrate of 0.2 mol / L and a molar concentration of zirconium nitrate of 0.2 mol / L; Etching catalyst, citric acid, and polyaspartic acid were added to the modification solution, ultrasonically treated at 85°C for 80 min, filtered, and dried to obtain the modified catalyst. The mass ratio of the etching catalyst, citric acid, polyaspartic acid, and modifying solution is 1:0.01:0.05:8.
[0040] (5) Mix tetraethyl orthosilicate and aluminum isopropoxide at a mass ratio of 2:1, add hydrochloric acid solution to adjust the pH to 2.8, and obtain the coating solution.
[0041] The modified catalyst was added to the coating solution and stirred at 200 rpm for 1 hour at 45°C. The mixture was then filtered and dried.
[0042] The dried material was added to a tube furnace and heated to 250°C at 5°C / min under air atmosphere, and held for 1 hour; then heated to 400°C at 5°C / min, and held for 1.5 hours; then heated to 500°C at 5°C / min, and held for 2 hours to obtain an antimony catalyst.
[0043] Example 4 A method for preparing an antimony-based catalyst includes the following steps: (1) Weigh the following components according to the mass percentage: 16% graphene aerogel, 18% dithionite pentoxide, 4% antimony acetate, 1.2% silicon carbide, 0.8% lanthanum oxide, and the balance titanium dioxide (anatase type). Ball mill and mix the components evenly to obtain an antimony-containing catalyst.
[0044] (2) The antimony-containing catalyst is placed in a plasma treatment device and subjected to plasma treatment to obtain an activated catalyst; The plasma treatment uses a mixture of argon and oxygen as the discharge gas, with a flow rate of 28 sccm, a power of 500 W, and a time of 30 min; the volume ratio of argon to oxygen is 4:1.
[0045] (3) The activated catalyst was placed in an 8% nitric acid solution at a solid-liquid ratio of 1g:8mL and immersed and etched at 55℃ for 50min; The activated catalyst was then placed in a 5% ammonia solution at a solid-liquid ratio of 1g:8mL and immersed and etched at 45°C for 50min; washed with water until neutral and dried to obtain the etching catalyst. (4) Add cerium nitrate and zirconium nitrate to water to prepare a modified solution with a molar concentration of cerium nitrate of 0.2 mol / L and a molar concentration of zirconium nitrate of 0.2 mol / L; Etching catalyst, citric acid, and polyaspartic acid were added to the modification solution, ultrasonically treated at 85°C for 80 min, filtered, and dried to obtain the modified catalyst. The mass ratio of the etching catalyst, citric acid, polyaspartic acid, and modifying solution is 1:0.02:0.02:8.
[0046] (5) Mix tetraethyl orthosilicate and aluminum isopropoxide at a mass ratio of 2:1, add hydrochloric acid solution to adjust the pH to 2.8, and obtain the coating solution.
[0047] The modified catalyst was added to the coating solution and stirred at 200 rpm for 1 hour at 45°C. The mixture was then filtered and dried.
[0048] The dried material was added to a tube furnace and heated to 220°C at 5°C / min under air atmosphere, and held for 2 hours; then heated to 350°C at 5°C / min, and held for 3 hours; then heated to 450°C at 5°C / min, and held for 4 hours to obtain an antimony catalyst.
[0049] Comparative Example 1 The antimony catalyst in Comparative Example 1 was not treated in any way.
[0050] A method for preparing an antimony-based catalyst includes the following steps: (1) Weigh the following components according to the mass percentage: 16% graphene aerogel, 18% dioxane pentoxide, 4% antimony acetate, 1.2% silicon carbide, 0.8% lanthanum oxide, and the balance titanium dioxide (anatase type). Ball mill and mix the components evenly to obtain an antimony catalyst.
[0051] Comparative Example 2 A method for preparing an antimony-based catalyst includes the following steps: (1) Weigh the following components according to the mass percentage: 16% graphene aerogel, 18% dithionite pentoxide, 4% antimony acetate, 1.2% silicon carbide, 0.8% lanthanum oxide, and the balance titanium dioxide (anatase type). Ball mill and mix the components evenly to obtain an antimony-containing catalyst.
[0052] (2) The antimony-containing catalyst is placed in a plasma treatment device and subjected to plasma treatment to obtain an activated catalyst; The plasma treatment uses a mixture of argon and oxygen as the discharge gas, with a flow rate of 28 sccm, a power of 500 W, and a time of 30 min; the volume ratio of argon to oxygen is 4:1.
[0053] (3) The activated catalyst was placed in an 8% nitric acid solution at a solid-liquid ratio of 1g:8mL and immersed and etched at 55℃ for 50min; The activated catalyst was then placed in a 5% ammonia solution at a solid-liquid ratio of 1g:8mL and immersed and etched at 45°C for 50min; washed with water until neutral and dried to obtain the etching catalyst. (4) Mix tetraethyl orthosilicate and aluminum isopropoxide at a mass ratio of 2:1, add hydrochloric acid solution to adjust the pH to 2.8, and obtain the coating solution.
[0054] The etching catalyst was added to the coating solution and stirred at 200 rpm for 1 hour at 45°C. The mixture was then filtered and dried.
[0055] The dried material was added to a tube furnace and heated to 250°C at 5°C / min under air atmosphere, and held for 1 hour; then heated to 400°C at 5°C / min, and held for 1.5 hours; then heated to 500°C at 5°C / min, and held for 2 hours to obtain an antimony catalyst.
[0056] Comparative Example 3 A method for preparing an antimony-based catalyst includes the following steps: (1) Weigh the following components according to the mass percentage: 16% graphene aerogel, 18% dithionite pentoxide, 4% antimony acetate, 1.2% silicon carbide, 0.8% lanthanum oxide, and the balance titanium dioxide (anatase type). Ball mill and mix the components evenly to obtain an antimony-containing catalyst.
[0057] (2) The antimony-containing catalyst is placed in a plasma treatment device and subjected to plasma treatment to obtain an activated catalyst; The plasma treatment uses a mixture of argon and oxygen as the discharge gas, with a flow rate of 28 sccm, a power of 500 W, and a time of 30 min; the volume ratio of argon to oxygen is 4:1.
[0058] (3) The activated catalyst was placed in an 8% nitric acid solution at a solid-liquid ratio of 1g:8mL and immersed and etched at 55℃ for 50min; The activated catalyst was then placed in a 5% ammonia solution at a solid-liquid ratio of 1g:8mL and immersed and etched at 45°C for 50min; washed with water until neutral and dried to obtain the etching catalyst. (4) Add cerium nitrate and zirconium nitrate to water to prepare a modified solution with a molar concentration of cerium nitrate of 0.2 mol / L and a molar concentration of zirconium nitrate of 0.2 mol / L; Etching catalyst, citric acid, and polyaspartic acid were added to the modification solution, and the mixture was ultrasonically treated at 85°C for 80 minutes. After filtration and drying, antimony-based catalysts were obtained.
[0059] Test case The reaction was carried out in a fixed-bed reactor with a catalyst dosage of 0.5 mL. The simulated flue gas composition was: 1000 ppm NH3, 1000 ppm N, 5 vol% O2, with He as the balance gas. The total flow rate was 500 mL / min, and the reaction space velocity was 60,000 h⁻¹. -1 The reaction temperature was 150℃. The NO and NO2 contents in the reaction products were analyzed and determined using a TESTO350 flue gas analyzer. N2O was analyzed using a gas chromatograph (Shimadzu 2014C) equipped with a PQ column. NO content was statistically analyzed. x Conversion rate and N2 selectivity.
[0060] Table 1
[0061] As can be seen from Table 1, this application first activates the antimony-containing catalyst through plasma to introduce active functional groups and improve surface reactivity. Then, it is etched sequentially with acid and alkali solutions, which can effectively control the pore structure of the catalyst and further improve its reactivity. Then, it is treated with citric acid, polyaspartic acid, and a modifying liquid to ensure that the modified components penetrate evenly into the pores and improve the loading stability. Finally, it is coated to form a physical coating barrier, which effectively improves the denitrification effect of flue gas.
[0062] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.
Claims
1. A method for preparing an antimony-based catalyst, characterized in that, Includes the following steps: (1) The antimony-containing catalyst is subjected to plasma treatment to obtain an activated catalyst; (2) The activated catalyst is first etched with acid solution, then etched with alkaline solution, washed with water until neutral, and dried to obtain the etched catalyst; (3) Add the etching catalyst, citric acid and polyaspartic acid to the modification solution, sonicate at 80~90℃ for 60~100min, filter and dry to obtain the modified catalyst; (4) The modified catalyst is added to the coating solution, filtered, dried, and then subjected to the first heat treatment, the second heat treatment, and the third heat treatment in sequence to obtain the antimony catalyst.
2. The method for preparing the antimony-based catalyst according to claim 1, characterized in that, The antimony-containing catalyst comprises the following components by mass percentage: 10-20% graphene aerogel, 15-20% dioxane pentoxide, 2-5% antimony acetate, 1-3% silicon carbide, 0.5-1% lanthanum oxide, and the balance titanium dioxide.
3. The method for preparing the antimony-based catalyst according to claim 1, characterized in that, The plasma treatment uses a mixture of argon and oxygen as the discharge gas, with a flow rate of 20-30 sccm, a power of 300-600 W, and a time of 20-40 min. The volume ratio of argon to oxygen is (3~5):
1.
4. The method for preparing the antimony-based catalyst according to claim 1, characterized in that, The acid solution is a nitric acid solution with a mass fraction of 2-10%, the solid-liquid ratio of the acid etching solution is 1g:(4-10)mL, and the etching time is 30-60min; The alkaline solution is an ammonia solution with a mass fraction of 2-10%, the solid-liquid ratio of the alkaline etching solution is 1g:(4-10)mL, and the etching time is 30-60min.
5. The method for preparing the antimony-based catalyst according to claim 1, characterized in that, The mass ratio of the etching catalyst, citric acid, polyaspartic acid, and modifying solution is 1:(0.01~0.02):(0.02~0.05):(4~10).
6. The method for preparing the antimony-based catalyst according to claim 1, characterized in that, The modified solution is a mixed solution containing cerium nitrate and zirconium nitrate, wherein the molar concentration of cerium nitrate in the mixed solution is 0.1~0.5 mol / L and the molar concentration of zirconium nitrate is 0.1~0.5 mol / L.
7. The method for preparing the antimony catalyst according to claim 1, characterized in that, The coating solution is prepared by mixing tetraethyl orthosilicate and aluminum isopropoxide in a mass ratio of (2~3):1, adding hydrochloric acid solution to adjust the pH to 2~3, and obtaining the coating solution.
8. The method for preparing antimony catalyst according to claim 1, characterized in that, The temperature of the first heat treatment is 200~250℃, and the time is 1~2 hours; The second heat treatment is performed at a temperature of 350~400℃ for 1.5~3 hours. The third heat treatment is performed at a temperature of 450-500℃ for 2-4 hours.
9. An antimony-based catalyst, characterized in that, It is prepared by any of the preparation methods described in claims 1 to 8.
10. The application of the antimony-based catalyst according to claim 9 in flue gas denitrification.