Low-temperature water-resistant sulfur-poisoning-resistant vanadium-based catalyst, and preparation method and application thereof

Abstract

The application discloses a low-temperature water-sulfur-poisoning-resistant vanadium-based catalyst and a preparation method and application thereof, and the catalyst is prepared by adopting a template-hydrothermal method and takes V2O5 as an active component, a compound of CeO2 and Ho2O3 as a cocatalyst and a SO2 capturing agent, a hydrophobic submicron flake hydrotalcite as a carrier, a submicron flake CaSO4 as a template agent and azodicarbonamide as a morphology control agent. The mass percentage of the active component is 3% to 5% based on the mass of the hydrophobic submicron flake hydrotalcite carrier, the mass percentage of the cocatalyst is 5% to 10%, and the mass ratio of CeO2 to Ho2O3 in the cocatalyst is 1:0.5 to 1. The catalyst is environment-friendly, can catalytically reduce NO in flue gas into N2 at low temperature, and has excellent water-sulfur-poisoning-resistant performance.

Description

Technical Field

[0001] This invention relates to the field of environmentally friendly catalytic materials technology, and in particular to a method for preparing a low-temperature vanadium-based catalyst resistant to water and sulfur poisoning and its application. Background Technology

[0002] Nitrogen oxides (NO) x Nitrogen oxides (NOx) are one of the causes of pollutants such as smog and acid rain. With the imperative of achieving ultra-low emissions of pollutants, emission limits for NOx from non-power industries such as steel and cement are gradually being reduced. Currently, the flue gas pollutants emitted by industries such as steel and cement have complex compositions, which not only increases the difficulty of purification work but also makes catalysts susceptible to water-sulfur poisoning. For flue gas denitrification, selective catalytic reduction (SCR) denitrification technology is highly efficient and stable, becoming the mainstream technology and development direction for industrial applications both domestically and internationally. The core of SCR technology is the denitrification catalyst, and the development of low-temperature, water-sulfur poisoning-resistant vanadium-based catalysts is an important direction with both practical significance and theoretical demand.

[0003] Numerous patents both domestically and internationally disclose various types of denitrification catalysts and their preparation processes. Patents CN201310153273.5 and CN201310153875.0 both use manganese and cerium as active components, resulting in catalysts with high denitrification activity and strong resistance to alkali metal poisoning. Patent CN201310693174.6 uses manganese, iron, copper, and cerium oxides as active components, adds tungsten and molybdenum polyacid salts as additives, and uses titanium, aluminum, and silicon oxides as the support; the prepared low-temperature denitrification catalyst can achieve a denitrification rate of up to 90% in the temperature range of 125–200℃. Patent (CN201310480494.3) uses titanium-silicon composite oxide as the support, manganese oxide as the active component, and cerium and nickel oxides as additives; this catalyst has high denitrification activity and strong resistance to alkali metal poisoning. However, the manganese active component in the above patents has weak resistance to water effects; the catalyst is easily hydrolyzed, corroded, or collapsed in complex atmospheres containing water vapor and SO2, which is detrimental to the practical application of the catalyst. Summary of the Invention

[0004] The purpose of this invention is to address the current status and existing problems of flue gas denitrification in non-power industries, and to provide a method for preparing a low-temperature vanadium-based catalyst resistant to water and sulfur poisoning. To achieve the above-mentioned objective, the low-temperature vanadium-based catalyst resistant to water and sulfur poisoning of this invention adopts the following technical solution:

[0005] A low-temperature resistant vanadium-based catalyst for water-sulfur poisoning is prepared by a template-hydrothermal method, with V2O5 as the active component, a complex of CeO2 and Ho2O3 as the co-catalyst and SO2 scavenger, hydrophobic submicron layered double hydroxide as the support, submicron layered CaSO4 as the template agent, and azodicarbonamide as the morphology control agent.

[0006] Based on the mass of the hydrophobic submicron sheet hydrotalcite support, the mass percentage of the active component is 1% to 8%, the mass percentage of the co-catalyst is 1% to 12%, and the mass ratio of CeO2 to Ho2O3 in the co-catalyst is 1:0.3 to 1.5.

[0007] A method for preparing the above-mentioned catalyst is as follows:

[0008] (1) Preparation of submicron-sized CaSO4 template agent

[0009] KCl, dilute hydrochloric acid, CaSO4 and deionized water were mixed and stirred evenly, and then placed in a stirred hydrothermal reactor. The mixture was stirred continuously during the hydrothermal reaction. The solid after the reaction was removed and dried to obtain submicron CaSO4 template agent.

[0010] (2) Preparation of hydrophobic submicron sheet hydrotalcite carrier

[0011] The CaSO4 template agent, azodicarbonamide, hydrotalcite powder, NaOH and deionized water obtained in step (1) are mixed and stirred evenly, and then placed in a stirred hydrothermal reactor. During the hydrothermal reaction, the mixture is continuously stirred. The solid after the reaction is taken out, dried and placed in a tube furnace. N2 is introduced and heated and calcined to obtain a hydrophobic submicron sheet hydrotalcite carrier.

[0012] (3) Preparation of vanadium-based catalysts

[0013] Vanadium salt, cerium salt, holmium salt, and citric acid monohydrate were weighed and dissolved in deionized water and stirred evenly to obtain a precursor mixed solution. Then, the hydrophobic submicron sheet hydrotalcite carrier prepared in step (2) was placed in the precursor mixed solution, impregnated, dried and calcined to obtain a low-temperature resistant vanadium-based catalyst resistant to water and sulfur poisoning.

[0014] In the above method: in step (1), the mass ratio of KCl, dilute hydrochloric acid and CaSO4 is 1:4~12:18~42, and the concentration of dilute hydrochloric acid is 0.1~0.4mol / L.

[0015] In the above method: the temperature of the hydrothermal reaction in step (1) is 140-180℃ and the time of the hydrothermal reaction is 4-8h; the drying temperature is 80-100℃ and the drying time is 6-12h.

[0016] In the above method: the mass ratio of CaSO4, azodicarbonamide, hydrotalcite powder and NaOH in step (2) is 1:0.1~1:25~55:0.1~0.8.

[0017] In the above method: the hydrothermal reaction temperature in step (2) is 160-180℃, the hydrothermal reaction time is 4-8h; the drying temperature is 80-100℃, the drying time is 6-12h, the rate of N2 introduction is 20-30mL / min, the heating and calcination temperature is 500-600℃, and the heating and calcination time is 4-6h.

[0018] In the above method: the drying temperature in step (3) is 80-100℃ and the drying time is 6-12h; the calcination temperature is 500-600℃ and the calcination time is 4-6h.

[0019] In the above method: in step (3), the vanadium salt is ammonium metavanadate, the cerium salt is cerium nitrate hexahydrate or cerium chloride hexahydrate, and the holmium salt is holmium nitrate hexahydrate or holmium chloride hexahydrate.

[0020] The vanadium-based catalyst described in this invention is used in flue gas denitrification in non-power industries. More specifically, non-power industries refer to the steel or cement industries.

[0021] The catalytic reaction conditions and results of this invention: 0.5 mL of 40-60 mesh catalyst was poured into a quartz tube with an inner diameter of 8 mm. The quartz tube was placed in a tube furnace, and the heating reaction temperature was controlled by the tube furnace. Laboratory gas was used to simulate flue gas. The inlet gas components were: NO (500 ppm), NH3 (500 ppm), O2 (11 vol.%), SO2 (200 ppm), water vapor (5 vol.%), and the remainder being N2. The total gas flow rate was 500 mL / min. The NO and SO2 concentrations were tested using a Laoying 3021 portable carbon emission monitor. At 160℃, the NO removal efficiency was 100% after 5 minutes, and the SO2 oxidation rate was less than 1%. The catalyst activity did not decrease within 12 hours at 160℃.

[0022] Beneficial effects:

[0023] The catalyst prepared in this invention can efficiently catalyze the reduction of NO to N2 at low temperatures and exhibits excellent resistance to water-sulfur poisoning. Compared with existing technologies, this catalyst system uses submicron-sized CaSO4 sheets as templates and azodicarbonamide as morphology control agents to grow submicron-sized hydrotalcite supports. These supports possess the high specific surface area and hydrophobic properties of hydrotalcite, enabling efficient adsorption of NO and NH3 while minimizing contact between water molecules and active sites. This avoids competitive adsorption of water molecules and reactants at low temperatures and prevents the reaction of water, SO2, and NH3 on the catalyst surface to form ammonium bisulfate or ammonium bisulfite. Furthermore, the system uses a CeO2 and Ho2O3 composite as a co-catalyst, which enhances the redox performance of the active component V2O5, thereby improving the catalyst's reactivity at low temperatures. The presence of oxygen vacancies also facilitates reaction with SO2 or SO3, preventing the reaction between the active sites V2O5 and SO2, thus simultaneously enhancing the catalyst's low-temperature activity and resistance to sulfur poisoning. Attached Figure Description

[0024] Figure 1 Field emission scanning electron microscope image of the hydrophobic submicron sheet hydrotalcite carrier prepared in Example 1.

[0025] Figure 2 Field emission scanning electron microscope image of the submicron sheet hydrotalcite carrier prepared for Comparative Example 1.

[0026] Figure 3 The image shows a scanning electron microscope (SEM) image of the support prepared for Comparative Example 2. Detailed Implementation

[0027] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.

[0028] Example 1:

[0029] (1) Preparation of submicron-sized CaSO4 template agent

[0030] Weigh 1g KCl, 5g dilute hydrochloric acid with a concentration of 0.1mol / L, 20g CaSO4 and 100g deionized water, mix and stir evenly, then place in a stirred hydrothermal reactor and react at 140℃ for 8h, stirring continuously at a rate of 150rpm during the reaction. After the reaction is completed, take out the solid and dry it at 80℃ for 12h to obtain submicron CaSO4 template agent.

[0031] (2) Preparation of hydrophobic submicron sheet hydrotalcite carrier

[0032] Weigh 1g of the CaSO4 template agent obtained in step (1), 0.1g of azodicarbonamide, 30g of hydrotalcite powder, 0.1g of NaOH, and 200g of deionized water, mix and stir evenly, then place in a stirred hydrothermal reactor and react at 160℃ for 8h, stirring continuously at 150rpm during the reaction. After the reaction is complete, remove the solid, dry it at 80℃ for 12h, and then place it in a tube furnace. After introducing N2 (N2 flow rate of 20mL / min), heat to 500℃ and calcine for 6h to obtain a hydrophobic submicron sheet hydrotalcite support (electron microscopy image of the support is shown in [link]). Figure 1 );

[0033] (3) Preparation of vanadium-based catalysts

[0034] Weigh 0.77g ammonium metavanadate, 1.68g cerium nitrate hexahydrate, 0.78g holmium nitrate hexahydrate, and 1.54g citric acid monohydrate and dissolve them in 7.7g deionized water. Stir for 2 hours to obtain a precursor mixed solution. Then weigh 20g of the hydrophobic submicron sheet hydrotalcite carrier prepared in step (2) and place it in the precursor mixed solution. After impregnation, dry at 80℃ for 12 hours and then calcine at 500℃ for 6 hours in a muffle furnace to obtain a low-temperature resistant vanadium-based catalyst resistant to water and sulfur poisoning (the mass percentage of the active component is 3%, the mass percentage of the co-catalyst is 5%, and the mass ratio of CeO2 to Ho2O3 in the co-catalyst is 1:0.5).

[0035] (4) Catalyst activity test

[0036] Take 0.5 mL of 40-60 mesh catalyst and pour it into a quartz tube with an inner diameter of 8 mm. Place the quartz tube in a tube furnace and control the heating reaction temperature using the tube furnace. Laboratory gas was used to simulate flue gas. The inlet gas components were: NO (500 ppm), NH3 (500 ppm), O2 (11 vol.%), SO2 (200 ppm), water vapor (5 vol.%), and the remainder being N2. The total gas flow rate was 500 mL / min. The NO and SO2 concentrations were tested using a Laoying 3021 portable carbon emission monitor. At 120℃, the NO removal efficiency was 100% after 5 minutes (Table 1), and the SO2 oxidation rate was less than 0.87%. The catalyst activity showed no significant decline within 12 hours at 160℃ (Table 2).

[0037] Example 2:

[0038] (1) Preparation of submicron-sized CaSO4 template agent

[0039] Weigh 1g KCl, 10g dilute hydrochloric acid with a concentration of 0.2mol / L, 40g CaSO4 and 150g deionized water, mix and stir evenly, then place in a stirred hydrothermal reactor and react at 180℃ for 4h, stirring continuously at a rate of 200rpm during the reaction. After the reaction is completed, take out the solid and dry it at 100℃ for 6h to obtain submicron CaSO4 template agent.

[0040] (2) Preparation of hydrophobic submicron sheet hydrotalcite carrier

[0041] Weigh 1g of the CaSO4 template agent obtained in step (1), 0.5g of azodicarbonamide, 50g of hydrotalcite powder, 0.5g of NaOH and 400g of deionized water, mix and stir evenly, then place in a stirred hydrothermal reactor, hydrothermally react at 180℃ for 4h, and continuously stir at a rate of 200rpm during the reaction. After the reaction is completed, take out the solid, dry at 100℃ for 6h, place in a tube furnace, introduce N2 (N2 flow rate is 30mL / min) and heat to 600℃ for calcination for 4h to obtain hydrophobic submicron sheet hydrotalcite carrier;

[0042] (3) Preparation of vanadium-based catalysts

[0043] Weigh 1.29g ammonium metavanadate, 1.54g cerium chloride hexahydrate, 2.01g holmium chloride hexahydrate, and 3.87g citric acid monohydrate and dissolve them in 25.8g deionized water. Stir for 2 hours to obtain a precursor mixed solution. Then weigh 20g of the hydrophobic submicron sheet hydrotalcite carrier prepared in step (2) and place it in the precursor mixed solution. After impregnation, dry at 100℃ for 6 hours and then calcine at 600℃ for 4 hours in a muffle furnace to obtain a low-temperature resistant vanadium-based catalyst resistant to water and sulfur poisoning (the mass percentage of the active component is 5%, the mass percentage of the co-catalyst is 10%, and the mass ratio of CeO2 to Ho2O3 in the co-catalyst is 1:1).

[0044] (4) Catalyst activity test

[0045] Take 0.5 mL of 40-60 mesh catalyst and pour it into a quartz tube with an inner diameter of 8 mm. Place the quartz tube in a tube furnace and control the heating reaction temperature using the tube furnace. Laboratory gas was used to simulate flue gas. The inlet gas components were: NO (500 ppm), NH3 (500 ppm), O2 (11 vol.%), SO2 (200 ppm), water vapor (5 vol.%), and the remainder being N2. The total gas flow rate was 500 mL / min. The NO and SO2 concentrations were tested using a Laoying 3021 portable carbon emission monitor. After 5 minutes at 160℃, the NO removal efficiency was 100%, and the SO2 oxidation rate was less than 0.98%. Specific data are shown in Table 1.

[0046] Example 3:

[0047] (1) Preparation of submicron-sized CaSO4 template agent

[0048] Weigh 1g KCl, 8g dilute hydrochloric acid with a concentration of 0.15mol / L, 30g CaSO4 and 120g deionized water, mix and stir evenly, then place in a stirred hydrothermal reactor and react at 160℃ for 6h, stirring continuously at a rate of 180rpm during the reaction. After the reaction is completed, take out the solid and dry it at 90℃ for 10h to obtain submicron CaSO4 template agent.

[0049] (2) Preparation of hydrophobic submicron sheet hydrotalcite carrier

[0050] Weigh 1g of the CaSO4 template agent obtained in step (1), 0.3g of azodicarbonamide, 40g of hydrotalcite powder, 0.4g of NaOH and 300g of deionized water, mix and stir evenly, then place in a stirred hydrothermal reactor, and hydrothermally react at 170℃ for 6h, while continuously stirring at a rate of 180rpm during the reaction. After the reaction is completed, take out the solid, dry it at 90℃ for 10h, place it in a tube furnace, introduce N2 (N2 flow rate is 25mL / min) and heat to 550℃ for 5h to obtain hydrophobic submicron sheet hydrotalcite carrier;

[0051] (3) Preparation of vanadium-based catalysts

[0052] Weigh 1.03g ammonium metavanadate, 1.37g cerium chloride hexahydrate, 1.66g holmium nitrate hexahydrate, and 2.58g citric acid monohydrate and dissolve them in 15.45g deionized water. Stir for 2 hours to obtain a precursor mixture solution. Then weigh 20g of the hydrophobic submicron hydrotalcite support prepared in step (2) and place it in the precursor mixture solution. After impregnation, dry at 90℃ for 10 hours and then calcine at 550℃ for 5 hours in a muffle furnace to obtain a low-temperature resistant vanadium-based catalyst resistant to water and sulfur poisoning (the mass percentage of the active component is 4%, the mass percentage of the co-catalyst is 8%, and the mass ratio of CeO2 to Ho2O3 in the co-catalyst is 1:0.8).

[0053] (4) Catalyst activity test

[0054] Take 0.5 mL of 40-60 mesh catalyst and pour it into a quartz tube with an inner diameter of 8 mm. Place the quartz tube in a tube furnace and control the heating reaction temperature using the tube furnace. Laboratory gas was used to simulate flue gas. The inlet gas components were: NO (500 ppm), NH3 (500 ppm), O2 (11 vol.%), SO2 (200 ppm), water vapor (5 vol.%), and the remainder being N2. The total gas flow rate was 500 mL / min. The NO and SO2 concentrations were tested using a Laoying 3021 portable carbon emission monitor. After 5 minutes at 140℃, the NO removal efficiency was 100%, and the SO2 oxidation rate was less than 0.93%. Specific data are shown in Table 1.

[0055] Comparative Example 1:

[0056] (1) Catalyst preparation

[0057] Except that the morphology control agent azodicarbonamide was not added during catalyst preparation, the other conditions were the same as in Example 1;

[0058] (2) Catalyst activity test

[0059] Take 0.5 mL of 40-60 mesh catalyst and pour it into a quartz tube with an inner diameter of 8 mm. Place the quartz tube in a tube furnace and control the heating reaction temperature using the tube furnace. Laboratory gas was prepared to simulate flue gas. The inlet gas components were: NO (500 ppm), NH3 (500 ppm), O2 (11 vol.%), SO2 (200 ppm), water vapor (5 vol.%), and the remainder being N2. The total gas flow rate was 500 mL / min. The NO and SO2 concentrations were tested using a Laoying 3021 portable carbon emission monitor. After 5 minutes at 120℃, the NO removal efficiency was 36.7%. Specific data are shown in Table 1.

[0060] (3) Comparison effect

[0061] Compared with Example 1, it can be seen that if the morphology control agent azodicarbonamide is not added during catalyst preparation, the NO conversion rate of the catalyst decreases significantly. This is mainly because although the catalyst support with a template agent can also grow into submicron sheets ( Figure 2 However, the growth is incomplete and the surface is smooth, which significantly reduces the hydrophobicity and thus the catalytic activity.

[0062] Comparative Example 2:

[0063] (1) Catalyst preparation

[0064] Except that submicron CaSO4 template agent was not added during catalyst preparation, the other conditions were the same as in Example 2;

[0065] (2) Catalyst activity test

[0066] Take 0.5 mL of 40-60 mesh catalyst and pour it into a quartz tube with an inner diameter of 8 mm. Place the quartz tube in a tube furnace and control the heating reaction temperature using the tube furnace. Laboratory gas was used to simulate flue gas. The inlet gas components were: NO (500 ppm), NH3 (500 ppm), O2 (11 vol.%), SO2 (200 ppm), water vapor (5 vol.%), and the remainder being N2. The total gas flow rate was 500 mL / min. The NO and SO2 concentrations were tested using a Laoying 3021 portable carbon emission monitor. After 5 minutes at 120℃, the NO removal efficiency was 16.5%. Specific data are shown in Table 1.

[0067] (3) Comparison effect

[0068] Compared with Example 2, it can be seen that if the submicron-sized CaSO4 template agent is not added during catalyst preparation, the NO conversion rate of the catalyst decreases significantly. This is mainly due to the lack of a template agent, which prevents the support from growing into nanosphere particles. Figure 3 This leads to a significant decrease in catalytic activity.

[0069] Comparative Example 3:

[0070] (1) Catalyst preparation

[0071] Except that the complex of CeO2 and Ho2O3 co-catalysts was not added during catalyst preparation, the other conditions were the same as in Example 1;

[0072] (2) Catalyst activity test

[0073] Take 0.5 mL of 40-60 mesh catalyst and pour it into a quartz tube with an inner diameter of 8 mm. Place the quartz tube in a tube furnace and control the heating reaction temperature using the tube furnace. Laboratory gas was used to simulate flue gas. The inlet gas components were: NO (500 ppm), NH3 (500 ppm), O2 (11 vol.%), SO2 (200 ppm), water vapor (5 vol.%), and the remainder being N2. The total gas flow rate was 500 mL / min. The NO and SO2 concentrations were tested using a Laoying 3021 portable carbon emission monitor. At 120℃, the NO removal efficiency was 64.8% after 5 minutes. The catalyst activity significantly decreased within 12 hours at 160℃. Specific data are shown in Table 3.

[0074] (3) Comparison effect

[0075] Compared with Example 1, it can be seen that if the complex of CeO2 and Ho2O3 is not added during catalyst preparation, the NO conversion rate of the catalyst decreases significantly, and the resistance to water and sulfur poisoning also decreases significantly. This is mainly because the complex of CeO2 and Ho2O3 not only improves the redox performance of V2O5, thereby increasing the NO conversion rate, but also improves the resistance to water and sulfur poisoning as a SO2 or SO3 scavenger.

[0076] Table 1 shows the NO conversion rates of Examples 1-3 and Comparative Examples 1-3.

[0077]

[0078] Table 2 shows the NO conversion rate of Example 1 at 160℃ for different times.

[0079] Time (h) 0.5 1 2 3 4 5 6 7 8 9 10 11 12 NO conversion rate (%) 100 100 100 100 100 99.8 99.9 100 99.6 99.8 99.7 99.6 99.6

[0080] Table 3 shows the NO conversion rate of Comparative Example 3 at 160℃ for different times.

[0081] Time (h) 0.5 1 2 3 4 5 6 7 8 9 10 11 12 NO conversion rate (%) 92.4 91.6 91.1 90.3 89.2 86.4 81.6 74.8 65.7 55.1 54.3 54.2 54.2

Claims

1. A method for preparing a low-temperature vanadium-based catalyst resistant to water-sulfur poisoning, characterized in that: The catalyst is prepared as follows: (1) Preparation of submicron CaSO4 template agent KCl, dilute hydrochloric acid, CaSO4 and deionized water were mixed and stirred evenly, and then placed in a stirred hydrothermal reactor. The mixture was stirred continuously during the hydrothermal reaction. The solid after the reaction was removed and dried to obtain submicron CaSO4 template agent. (2) Preparation of hydrophobic submicron sheet hydrotalcite carrier The CaSO4 template agent, azodicarbonamide, hydrotalcite powder, NaOH and deionized water obtained in step (1) are mixed and stirred evenly, and then placed in a stirred hydrothermal reactor. During the hydrothermal reaction, the mixture is continuously stirred. The solid after the reaction is taken out, dried and placed in a tube furnace. N2 is introduced and heated and calcined to obtain a hydrophobic submicron sheet hydrotalcite carrier. (3) Preparation of vanadium-based catalysts Vanadium salt, cerium salt, holmium salt, and citric acid monohydrate were weighed and dissolved in deionized water and stirred evenly to obtain a precursor mixed solution. Then, the hydrophobic submicron sheet hydrotalcite carrier obtained in step (2) was placed in the precursor mixed solution, impregnated, dried and calcined to obtain a low-temperature resistant vanadium-based catalyst resistant to water and sulfur poisoning.

2. The preparation method according to claim 1, characterized in that: In step (1), the mass ratio of KCl, dilute hydrochloric acid and CaSO4 is 1:4~12:18~42, and the concentration of dilute hydrochloric acid is 0.1~0.4mol / L.

3. The preparation method according to claim 1, characterized in that: In step (1), the hydrothermal reaction temperature is 140~180℃ and the hydrothermal reaction time is 4~8h; the drying temperature is 80~100℃ and the drying time is 6~12h.

4. The preparation method according to claim 1, characterized in that: In step (2), the mass ratio of CaSO4, azodicarbonamide, hydrotalcite powder and NaOH is 1:0.1~1:25~55:0.1~0.

8.

5. The preparation method according to claim 1, characterized in that: In step (2), the hydrothermal reaction temperature is 160~180℃ and the hydrothermal reaction time is 4~8h; the drying temperature is 80~100℃ and the drying time is 6~12h; the rate of N2 introduction is 20~30mL / min; the heating and calcination temperature is 500~600℃ and the heating and calcination time is 4~6h.

6. The preparation method according to claim 1, characterized in that: In step (3), the drying temperature is 80~100℃ and the drying time is 6~12h; the calcination temperature is 500~600℃ and the calcination time is 4~6h.

7. The preparation method according to claim 1, characterized in that: In step (3), the vanadium salt is ammonium metavanadate, the cerium salt is cerium nitrate hexahydrate or cerium chloride hexahydrate, and the holmium salt is holmium nitrate hexahydrate or holmium chloride hexahydrate.

8. A low-temperature resistant vanadium-based catalyst for water-sulfur poisoning prepared by the method of claim 1, characterized in that: The catalyst uses V₂O₅ as the active component, and a complex of CeO₂ and Ho₂O₃ as a co-catalyst and SO₂ scavenger. Based on the mass of the hydrophobic submicron sheet hydrotalcite carrier, the mass percentage of the active component is 1%~8%, the mass percentage of the co-catalyst is 1%~12%, and the mass ratio of CeO2 to Ho2O3 in the co-catalyst is 1:0.3~1.

5.

9. The application of the vanadium-based catalyst prepared by the method of claim 1 in flue gas denitrification in non-electric industries.

10. The application according to claim 9, specifically the non-electric industry refers to the steel or cement industry.

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