Water-resistant sulfur-resistant catalyst as well as preparation method and application thereof

Abstract

The invention discloses a water-resistant sulfur-resistant catalyst as well as a preparation method and application thereof. The catalyst comprises a TiO2 carrier and active components, and the active components comprise high-activity oxides V2O5 and WO3 and CeO2 treated by sulfuric acid. The active components are loaded on the carrier through the process steps of sulfuric acid pretreatment, dipping, drying, calcining and the like, and finally the high-performance denitration water-resistant and sulfur-resistant catalyst is prepared. The obtained catalyst can achieve the NO conversion rate of 95% or above within the temperature range of 220-400 DEG C, shows excellent sulfur resistance and water resistance, and can stably operate for a long time under the conditions of 350 ppm of sulfur dioxide and 5 vol.% of water vapor. The catalyst is suitable for efficient control and removal of NO pollutants in tail gas of a coal-fired power plant under a variable load operation condition.

Description

Technical Field

[0001] The present invention relates to a water-resistant and sulfur-resistant catalyst and a preparation method and application thereof, in particular to a sulfuric acid pretreated cerium dioxide modified vanadium tungsten titanium denitration water-resistant and sulfur-resistant catalyst and a preparation method and application thereof, belonging to the field of air pollution purification. Background Art

[0002] Nitrogen oxides (NOx) are a typical atmospheric pollutant, of which NO accounts for more than 90% of NOx emissions, which can cause environmental problems such as acid rain, photochemical smog and greenhouse effect. Studies have shown that NOx is a PM 2.5 and O3 pollution, the nitrate generated by its conversion is the key precursor of PM 2.5 Oxygen is the main component of nitrogen oxides (NOx), and its photochemical reaction with volatile organic compounds (VOCs) produces O3. Therefore, controlling and reducing NOx emissions from coal-fired power plants is a core task in reducing NOx emissions nationwide.

[0003] In recent years, thermal power plants have been in a low-load state for a long time in actual operation, and the outlet flue gas temperature is difficult to reach the operating temperature range (300-400°C) of the currently widely used VW / Ti denitrification catalyst, affecting the denitrification effect. In addition, VW / Ti is easily poisoned and deactivated by sulfur during variable load operation of power plants, resulting in a sharp reduction in lifespan. Therefore, it is particularly important to develop a modified catalyst suitable for the variable load conditions of coal-fired power plants that has wide-temperature activity, sulfur resistance and stability.

[0004] Currently, the wide-temperature SCR denitrification catalysts that have been widely studied and have practical industrial application value are mainly supported catalysts. Therefore, they can be modified with metal oxides to achieve industrial application of wide-temperature denitrification. Although doping with metal oxides is beneficial to improving the low-temperature activity of the catalyst to a certain extent, most modifications have not been well solved in terms of water and sulfur resistance. Among them, acidification can enhance the surface acidity of the catalyst, thereby achieving the purpose of enhancing activity and sulfur resistance. Therefore, the development of a modified VW / Ti catalyst suitable for variable load conditions in coal-fired power plants and having wide-temperature activity, sulfur resistance and stability through acidification modification is the key to this patent research. Summary of the Invention

[0005] Purpose of the invention: In view of the defects of existing commercial VW / Ti catalysts such as insufficient activity and easy sulfur poisoning under variable load conditions, the first purpose of the present invention is to provide a sulfuric acid pretreated cerium dioxide modified vanadium tungsten titanium denitrification and water-sulfur resistant catalyst with good activity, water resistance and sulfur resistance. The second purpose of the present invention is to provide a method for preparing the catalyst. The third purpose of the present invention is to provide the application of the catalyst in flue gas denitrification.

[0006] Technical solution: The water-resistant and sulfur-resistant catalyst described in the present invention includes a TiO2 carrier and active components, wherein the active components include highly active oxides V2O5, WO3 and sulfuric acid-treated CeO2.

[0007] Furthermore, the water- and sulfur-resistant catalyst has an active temperature range of 220-400°C, achieving denitrification activity exceeding 95%. The active components, V2O5 and WO3, are uniformly dispersed on the TiO2 support, while the sulfuric acid-treated CeO2 (CeO2-xS) significantly enhances the catalyst's water- and sulfur-resistant properties and low-temperature denitrification activity.

[0008] Furthermore, the preparation of CeO2 treated with sulfuric acid comprises the following steps:

[0009] (A1) calcining Ce(NO)3·6H2O, grinding, and sieving to obtain CeO2 powder;

[0010] (A2) CeO2 powder is mixed with H2SO4 solution, heated and stirred, dried, calcined, ground, and sieved to obtain sulfuric acid-treated CeO2 powder CeO2-xS.

[0011] Furthermore, in step (A1), the calcination heating rate is less than 5°C / min, the calcination temperature is 200-500°C, the calcination time is more than 3 hours, and the sieving is to pass through a sieve with a mesh size of less than 60 mesh. In step (A2), the concentration of the H2SO4 solution is 0.5-1.0 mol / L, and the mass volume ratio of CeO2 powder to H2SO4 solution is 1:(3-7) g / mL. In particular, when the concentration of the H2SO4 solution is 1 mol / L, the mass volume ratio of CeO2 powder to H2SO4 solution is 1:5 g / mL, which is the best effect. The heating and stirring temperature is 60-80°C, and the heating and stirring are carried out until the excess aqueous solution evaporates to form a semi-dried mixture. The drying temperature is 100-120°C, the drying time is 10-15 hours, the calcination heating rate is less than 5°C / min, the calcination temperature is 200-500°C, the calcination time is more than 3 hours, and the sieving is to pass through a sieve with a mesh size of less than 60 mesh.

[0012] The preparation method of the water-resistant and sulfur-resistant catalyst of the present invention comprises the following steps:

[0013] (B1) adding anatase TiO2 support, ammonium metavanadate, ammonium metatungstate, and CeO2-xS to water, heating and stirring to obtain a semi-dried mixture;

[0014] (B2) drying the semi-dried mixture, calcining, grinding, and sieving to obtain.

[0015] Furthermore, in step (B1), the mass ratio of ammonium metavanadate: ammonium metatungstate: CeO2-xS: TiO2 is 0.01:0.05:(0.03-0.07):1, and the temperature of heating and stirring is 60-80°C. In step (B2), the drying temperature is 100-120°C, the drying time is 10-15 hours, the calcination heating rate is less than 5°C / min, the calcination temperature is 200-500°C, the calcination time is more than 3 hours, and the sieve is sieve with a mesh size of less than 60 mesh.

[0016] The invention discloses an application of the water-resistant and sulfur-resistant catalyst in flue gas denitrification.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) Sulfuric acid acidification enhances acidity and sulfur resistance: The sulfuric acid pretreatment adopted in the present invention can effectively and significantly enhance the acidity of the catalyst, increase the adsorption of NH3 on the catalyst surface, and form SO4 on the surface. 2- –NH4 + , among which SO4 2- The active metal oxide of the catalyst can be highly dispersed on the surface of the carrier, thereby achieving enhanced activity and sulfur resistance. (2) Synergistic effect of CeO2-1S and 1% V2O5-5% WO3 / TiO2: The rare earth metal oxide CeO2 pretreated by the present invention is doped and loaded on the carrier. By increasing the proportion of chemically adsorbed oxygen, the oxygen storage capacity of the catalyst is enhanced. The interaction between CeO2 and WOx produces more Bronsted acid sites, thereby improving the low-temperature activity of the catalyst. (3) Economic and environmental protection: The rare earth metal Ce described in the present invention is one of the rare earth elements with the highest abundance and lowest cost. It has excellent redox performance and environmental friendliness. CeO2 has low toxicity, high reserves and unique oxygen vacancy characteristics. The sulfuric acid acidification process is simple, making it an ideal choice for improving the economic efficiency and sustainability of the catalyst. (4) The present invention loads the active component on the carrier through sulfuric acid pretreatment, impregnation, drying, calcination and other process steps, and finally produces a high-performance denitrification, water-resistant and sulfur-resistant catalyst. The catalyst produced by this invention can achieve NO conversion rates exceeding 95% within a temperature range of 220-400°C. It also exhibits excellent sulfur and water resistance, and can operate stably for extended periods under conditions of 350 mg / L sulfur dioxide and 5 vol.% water vapor. This catalyst is suitable for the efficient control and removal of NO pollutants from coal-fired power plant exhaust gases under variable load conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a denitration performance curve of the catalyst prepared by the present invention;

[0019] Figure 2 It is a curve diagram of the water-sulfur resistance of the catalyst prepared by the present invention. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0021] Example 1

[0022] 1. Sulfuric acid pretreatment:

[0023] (1) Weigh 5 g of Ce(NO)3·6H2O powder and place it in a muffle furnace. Heating the temperature to 300°C at a rate of 5°C / min in air atmosphere and maintaining the temperature for 3 h. The powder cooled to room temperature was ground and sieved to obtain CeO2 powder with a mesh size less than 60.

[0024] (2) Measure 5.43 mL of 98% concentrated sulfuric acid solution and dilute to 100 mL in deionized water to obtain a 1 mol / L H2SO4 solution;

[0025] (3) Weigh 0.2 g of CeO2 powder and mix it with 1 mL of 1 mol / L H2SO4 solution. Place it in a 60°C oil bath and stir until the excess aqueous solution evaporates to obtain a semi-dried mixture.

[0026] (4) The semi-dried mixture was placed in an oven at 105°C for 10 h, then placed in a muffle furnace, heated to 300°C at a heating rate of 5°C / min in an air atmosphere, and maintained for 3 h. The mixture was cooled to room temperature, ground, and sieved to obtain sulfuric acid-pretreated CeO2 powder with a particle size of less than 60 mesh, which was designated as CeO2-1S.

[0027] 2. Preparation of catalyst by impregnation method:

[0028] Weigh 0.0514g ammonium metavanadate (NH4VO3), 0.212g ammonium metatungstate (H 28 N6O 41 W 12 ), 0.2 g of CeO2-1S powder with a particle size less than 60 mesh obtained above was mixed with 4 g of anatase-type TiO2 carrier in 30 mL of deionized water, and stirred in a 60°C oil bath to mix evenly until excess aqueous solution was evaporated to obtain a semi-dried mixture; the semi-dried mixture was placed in an oven at 105°C and dried for 10 h.

[0029] 3. High temperature calcination:

[0030] The dried mixture in step 2 was placed in a muffle furnace, heated to 500°C at a heating rate of 5°C / min under air atmosphere, and maintained for 5 hours. The powder cooled to room temperature was ground and sieved to obtain a 40-60 mesh catalyst powder, recorded as 1% V2O5-5% WO3-5% CeO2-1S / TiO2.

[0031] Example 2

[0032] The preparation process is the same as in Example 1, except that the amount of sulfuric acid used is different, as follows:

[0033] 1. Sulfuric acid pretreatment:

[0034] (1) Weigh 5 g of Ce(NO)3·6H2O powder and place it in a muffle furnace. Heating the temperature to 300°C at a rate of 5°C / min in air atmosphere and maintaining the temperature for 3 h. The powder cooled to room temperature was ground and sieved to obtain CeO2 powder with a mesh size less than 60.

[0035] (2) Measure 2.72 mL of 98% concentrated sulfuric acid solution and dilute to 100 mL in deionized water to obtain a 0.5 mol / L H2SO4 solution;

[0036] (3) Weigh 0.2 g of CeO2 powder and mix it with 1 mL of 0.5 mol / L H2SO4 solution. Place it in a 60°C oil bath and stir until the excess aqueous solution evaporates to obtain a semi-dried mixture.

[0037] (4) The semi-dried mixture was placed in an oven at 105°C for 10 h, then placed in a muffle furnace, heated to 300°C at a heating rate of 5°C / min in an air atmosphere, and maintained for 3 h. The mixture was cooled to room temperature, ground, and sieved to obtain sulfuric acid-pretreated CeO2 powder with a particle size of less than 60 mesh, which was designated as CeO2-0.5S.

[0038] 2. Preparation of catalyst by impregnation method:

[0039] Weigh 0.0514g ammonium metavanadate (NH4VO3), 0.212g ammonium metatungstate (H 28 N6O 41 W 12 ), 0.2 g of CeO2-0.5S powder with a particle size less than 60 mesh obtained above was mixed with 4 g of anatase-type TiO2 carrier in 30 mL of deionized water, and stirred in a 60°C oil bath to mix evenly until excess aqueous solution was evaporated to obtain a semi-dried mixture; the semi-dried mixture was placed in an oven at 105°C and dried for 10 h.

[0040] 3. High temperature calcination:

[0041] The dried mixture in step 2 was placed in a muffle furnace, heated to 500°C at a heating rate of 5°C / min under air atmosphere, and maintained for 5 hours. The powder cooled to room temperature was ground and sieved to obtain a 40-60 mesh catalyst powder, recorded as 1% V2O5-5% WO3-5% CeO2-0.5S / TiO2.

[0042] Example 3

[0043] The preparation process is the same as that of Example 1, except that the amount of sulfuric acid used is different, as follows:

[0044] 1. Sulfuric acid pretreatment:

[0045] (1) Weigh 5 g of Ce(NO)3·6H2O powder and place it in a muffle furnace. Heating the temperature to 300°C at a rate of 5°C / min in air atmosphere and maintaining the temperature for 3 h. The powder cooled to room temperature was ground and sieved to obtain CeO2 powder with a mesh size less than 60.

[0046] (2) Measure 8.15 mL of 98% concentrated sulfuric acid solution and dilute to 100 mL in deionized water to obtain a 1.5 mol / L H2SO4 solution;

[0047] (3) Weigh 0.2 g of CeO2 powder and mix it with 1 mL of 1.5 mol / L H2SO4 solution. Place it in a 60°C oil bath and stir until the excess aqueous solution evaporates to obtain a semi-dried mixture.

[0048] (4) The semi-dried mixture was placed in an oven at 105°C for 10 h, then placed in a muffle furnace, heated to 300°C at a heating rate of 5°C / min in an air atmosphere, and maintained for 3 h. The mixture was cooled to room temperature, ground, and sieved to obtain sulfuric acid-pretreated CeO2 powder with a particle size of less than 60 mesh, which was designated as CeO2-1.5S.

[0049] 2. Preparation of catalyst by impregnation method:

[0050] Weigh 0.0514g ammonium metavanadate (NH4VO3), 0.212g ammonium metatungstate (H 28 N6O 41 W 12 ), the above 0.2 g of CeO2-1.5S powder with a size less than 60 mesh was mixed with 4 g of anatase-type TiO2 carrier in 30 mL of deionized water, and stirred in a 60°C oil bath to mix evenly until excess aqueous solution was evaporated to obtain a semi-dried mixture; the semi-dried mixture was placed in an oven at 105°C and dried for 10 h.

[0051] 3. High temperature calcination:

[0052] The dried mixture in step 2 was placed in a muffle furnace, heated to 500°C at a heating rate of 5°C / min under air atmosphere, and maintained for 5 hours. The powder cooled to room temperature was ground and sieved to obtain a 40-60 mesh catalyst powder, recorded as 1% V2O5-5% WO3-5% CeO2-1.5S / TiO2.

[0053] Example 4

[0054] The preparation process is the same as that of Example 1, except that the amount of sulfuric acid used is different, as follows:

[0055] 1. Sulfuric acid pretreatment:

[0056] (1) Weigh 5 g of Ce(NO)3·6H2O powder and place it in a muffle furnace. Heating the temperature to 300°C at a rate of 5°C / min in air atmosphere and maintaining the temperature for 3 h. The powder cooled to room temperature was ground and sieved to obtain CeO2 powder with a mesh size less than 60.

[0057] (2) Measure 10.87 mL of 98% concentrated sulfuric acid solution and dilute to 100 mL in deionized water to obtain a 2 mol / L H2SO4 solution;

[0058] (3) Weigh 0.2 g of CeO2 powder and mix it with 1 mL of 2 mol / L H2SO4 solution. Place it in a 60°C oil bath and stir until the excess aqueous solution evaporates to obtain a semi-dried mixture.

[0059] (4) The semi-dried mixture was placed in an oven at 105°C for 10 h, then placed in a muffle furnace, heated to 300°C at a heating rate of 5°C / min in an air atmosphere, and maintained for 3 h. The mixture was cooled to room temperature, ground, and sieved to obtain sulfuric acid-pretreated CeO2 powder with a particle size of less than 60 mesh, which was designated as CeO2-2S.

[0060] 2. Preparation of catalyst by impregnation method:

[0061] Weigh 0.0514g ammonium metavanadate (NH4VO3), 0.212g ammonium metatungstate (H 28 N6O 41 W 12 ), 0.2 g of CeO2-2S powder with a particle size less than 60 mesh obtained above was mixed with 4 g of anatase-type TiO2 carrier in 30 mL of deionized water, and stirred in a 60°C oil bath to mix evenly until excess aqueous solution was evaporated to obtain a semi-dried mixture; the semi-dried mixture was placed in an oven at 105°C and dried for 10 h.

[0062] 3. High temperature calcination:

[0063] The dried mixture in step 2 was placed in a muffle furnace, heated to 500°C at a heating rate of 5°C / min under air atmosphere, and maintained for 5 hours. The powder cooled to room temperature was ground and sieved to obtain a 40-60 mesh catalyst powder, recorded as 1% V2O5-5% WO3-5% CeO2-2S / TiO2.

[0064] Comparative Example 1

[0065] The same preparation as in Example 1 is performed except that Ce(NO)3·6H2O is not used, i.e., step 1 in Example 1 is omitted, specifically as follows:

[0066] 1. Preparation of catalyst by impregnation method: weigh 0.0514g ammonium metavanadate (NH4VO3), 0.212g ammonium metatungstate (H 28 N6O 41 W 12 ), mixed with 4 g of anatase TiO2 carrier in 30 mL of deionized water, stirred in a 60°C oil bath to mix evenly until excess aqueous solution evaporated to obtain a semi-dried mixture; the semi-dried mixture was placed in an oven at 105°C and dried for 10 h.

[0067] 2. High-temperature calcination: Place the dried mixture in step 1 in a muffle furnace, heat it to 500°C at a heating rate of 5°C / min in an air atmosphere, and maintain it for 5 hours. Grind and sieve the powder cooled to room temperature to obtain a 40-60 mesh catalyst powder, recorded as 1% V2O5-5% WO3 / TiO2.

[0068] Comparative Example 2

[0069] The same method as in Example 1 is used except that Ce is not pretreated with sulfuric acid and Ce(NO)3·6H2O is used directly, i.e., step 1 in Example 1 is omitted and Ce(NO)3·6H2O is directly added instead of CeO2-1S in Example 1, as follows:

[0070] 1. Preparation of catalyst by impregnation method: weigh 0.0514g ammonium metavanadate (NH4VO3), 0.212g ammonium metatungstate (H 28 N6O 41 W 12 ), 0.5046 g of cerium nitrate (Ce(NO)3·6H2O) and 4 g of anatase-type TiO2 carrier were mixed in 30 mL of deionized water, and stirred in a 60°C oil bath to mix evenly until excess aqueous solution was evaporated to obtain a semi-dried mixture; the semi-dried mixture was placed in an oven at 105°C and dried for 10 h.

[0071] 2. High-temperature calcination: Place the dried mixture in step 1 in a muffle furnace, heat it to 500°C at a heating rate of 5°C / min in an air atmosphere, and maintain it for 5 hours. Grind and sieve the powder cooled to room temperature to obtain a 40-60 mesh catalyst powder, recorded as 1% V2O5-5% WO3-5% CeO2 / TiO2.

[0072] Example 5 Denitrification Performance Test

[0073] The catalysts obtained in Examples 1-4 and Comparative Examples 1-2 were subjected to corresponding denitration performance tests, and the activity of the catalyst was expressed as the NO conversion rate, and the NO concentration was detected using a Testo 350 infrared flue gas analyzer. The specific test conditions are as follows: the activity test of NO catalytic reduction was carried out in a fixed-bed quartz tube reactor, the catalyst loading was 0.4 g, the particle size was 40-60 mesh, the reaction temperature was 160°C-400°C, the reaction temperature interval was 20°C, and the concentration at each temperature was based on the final stable reading of the flue gas analyzer. The concentration of NO in the raw gas was 1000 mg / L, the concentration of the reducing gas NH3 was 1000 mg / L, the volume concentration of O2 was 5%, N2 was the balance gas, and the total mixed flue gas volume was 200 mL / min; the reactor was a quartz tube with an inner diameter of 5 mm, and a vertical tubular heating furnace with a temperature control system provided the reaction temperature environment. The test results are as follows Figure 1 shown.

[0074] Depend on Figure 1 It can be seen that in Examples 1-4, within the test temperature range of 200°C-400°C, the catalyst removal rate of NO is maintained at about 80%, and within the low temperature range of 220-400°C, the removal rate of NO is close to 100%.

[0075] The catalysts obtained in Examples 1-4 and Comparative Examples 1-2 were subjected to corresponding water and sulfur poisoning resistance tests, and the activity of the catalyst was expressed by the NO conversion rate when water and sulfur dioxide were introduced. The specific test conditions are as follows: the activity test of NO catalytic reduction was carried out in a fixed-bed quartz tube reactor, the catalyst loading was 0.4 g, the particle size was 40-60 mesh, the reaction temperature was 240°C, and the concentration at this temperature was based on the final stable reading of the flue gas analyzer. The concentration of NO in the raw gas was 1000 mg / L, the concentration of the reducing gas NH3 was 1000 mg / L, the volume concentration of O2 was 5%, the volume concentration of H2O was 5%, the concentration of SO2 was 350 mg / L, N2 was the balance gas, and the total mixed flue gas volume was 200 mL / min; the reactor was a quartz tube with an inner diameter of 5 mm, and a vertical tubular heating furnace with a temperature control system provided the reaction temperature environment. The test results are as follows Figure 2 shown.

[0076] Although Figure 1 The NOx removal performance of each catalyst after treatment with sulfuric acid is not much different, but Figure 2As can be seen, Examples 1 and 2 exhibit excellent NO removal performance compared to Comparative Documents 1 and 2 in the presence of both H₂O and SO₂. In particular, the catalyst of Example 1 exhibits optimal performance in the presence of 5% vol. H₂O and 350 mg / L SO₂, maintaining a 100% NO removal rate for the first 40 hours. Its denitrification activity is virtually unaffected by water and sulfur dioxide, and it maintains a NO removal rate exceeding 70% after 51 hours. However, Examples 3 and 4, despite pretreating Ce with higher concentrations of sulfuric acid, exhibit inferior NO removal performance in the presence of both H₂O and SO₂ compared to those without sulfuric acid pretreatment. This may be because only an appropriate amount of sulfuric acid pretreatment can reduce sulfate formation on the catalyst in the presence of SO₂, inhibiting deposition on surface active sites.

Claims

1. A water-resistant and sulfur-resistant catalyst, characterized in that: The catalyst comprises a TiO2 carrier and active components, wherein the active components comprise highly active oxides V2O5, WO3 and CeO2 treated with sulfuric acid.

2. The water-resistant and sulfur-resistant catalyst according to claim 1, characterized in that: The active temperature range of the water-resistant and sulfur-resistant catalyst is 220-400°C, and the denitrification activity can reach more than 95% within this temperature range.

3. The water-resistant and sulfur-resistant catalyst according to claim 1, characterized in that: The preparation of CeO2 treated with sulfuric acid includes the following steps: (A1) calcining Ce(NO)3·6H2O, grinding, and sieving to obtain CeO2 powder; (A2) CeO2 powder is mixed with H2SO4 solution, heated and stirred, dried, calcined, ground, and sieved to obtain sulfuric acid-treated CeO2 powder CeO2-xS.

4. The water-resistant and sulfur-resistant catalyst according to claim 3, characterized in that: In step (A1), the heating rate of calcination is less than 5°C / min, the calcination temperature is 200-500°C, the calcination time is more than 3 hours, and the sieve is sieve holes of less than 60 mesh.

5. The water-resistant and sulfur-resistant catalyst according to claim 3, characterized in that: In step (A2), the concentration of the H2SO4 solution is 0.5-1.0 mol / L, the mass volume ratio of CeO2 powder to the H2SO4 solution is 1:(3-7) g / mL, the heating and stirring temperature is 60-80°C, and the heating and stirring are performed until the excess aqueous solution is evaporated to form a semi-dried mixture.

6. The water-resistant and sulfur-resistant catalyst according to claim 3, characterized in that: In step (A2), the drying temperature is 100-120°C, the drying time is 10-15h, the calcination heating rate is less than 5°C / min, the calcination temperature is 200-500°C, the calcination time is more than 3h, and the sieving is to pass through a sieve with a mesh size of less than 60 mesh.

7. The method for preparing the water-resistant and sulfur-resistant catalyst according to any one of claims 1 to 6, characterized in that: The following steps are involved: (B1) adding anatase TiO2 support, ammonium metavanadate, ammonium metatungstate, and CeO2-xS to water, heating and stirring to obtain a semi-dried mixture; (B2) drying the semi-dried mixture, calcining, grinding, and sieving to obtain.

8. The preparation method according to claim 7, characterized in that In step (B1), the mass ratio of ammonium metavanadate:ammonium metatungstate:CeO2-xS:TiO2 is 0.01:0.05:(0.03-0.07):1, and the heating and stirring temperature is 60-80°C.

9. The preparation method according to claim 7, characterized in that In step (B2), the drying temperature is 100-120°C, the drying time is 10-15h, the calcination heating rate is less than 5°C / min, the calcination temperature is 200-500°C, the calcination time is more than 3h, and the sieve is sieve holes of less than 60 mesh.

10. Use of the water-resistant and sulfur-resistant catalyst according to any one of claims 1 to 6 in flue gas denitrification.

Images