Mn-Me-Ti composite oxide powder, sulfur-resistant denitration catalyst and preparation method of Mn-Me-Ti composite oxide powder and sulfur-resistant denitration catalyst

Abstract

The invention discloses Mn-Me-Ti composite oxide powder, a sulfur-resistant denitration catalyst and preparation methods of the Mn-Me-Ti composite oxide powder and the sulfur-resistant denitration catalyst. The Mn-Me-Ti composite oxide powder is of a hollow mesoporous structure, and the specific surface area of the Mn-Me-Ti composite oxide powder is shown in the specification. Wherein Me is Ce, Sn, Sm or Y. The preparation method of the sulfur-resistant denitration catalyst comprises the following steps: S1, mixing the active component and the additive, and adding water to form slurry; the active components comprise Mn-Me-Ti composite oxide powder, a sulfur-resistant additive and a molecular sieve; s2, carrying out vacuum pugging and extrusion molding treatment on the slurry to obtain a catalyst blank; s3, drying and roasting the catalyst blank to obtain the sulfur-resistant denitration catalyst. The sulfur-resistant denitration catalyst disclosed by the invention shows good ultralow-temperature conversion efficiency and sulfur resistance under typical industrial conditions, is suitable for various complex flue gas treatment scenes, and has wide popularization and application prospects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalytic materials, and particularly relates to a Mn-Me-Ti composite oxide powder and a sulfur-resistant denitration catalyst and a preparation method thereof. BACKGROUND

[0002] Nitrogen oxide (NO x ) is one of the main atmospheric pollutants, and its emission into the environment can cause a series of ecological and health problems such as acid rain and photochemical smog. With the continuous increase of total industrial flue gas emissions and the gradual tightening of environmental protection standards, how to efficiently remove industrial source NO x has become an important issue that needs to be addressed. The selective catalytic reduction (SCR) technology has become the most mature and widely used denitration technology at present due to its high reaction selectivity, high NO x conversion efficiency and less by-products. However, the application of this technology under ultra-low temperature conditions (80-300℃) faces many challenges, especially in the sulfur-containing flue gas environment, the catalyst is easily poisoned and deactivated, which greatly limits its popularization and application in non-electricity industries such as steel, coking, cement and glass.

[0003] In industrial flue gas, SO2 is one of the most common associated gases. In the SCR reaction system, SO2 can be catalytically oxidized to SO3, which further reacts with NH3 and water vapor to generate viscous by-products such as ammonium bisulfate (NH4HSO4) or ammonium sulfate ((NH4)2SO4). These substances are easily condensed and deposited on the catalyst surface at low temperatures, leading to multiple deactivation mechanisms such as active site shielding, pore blockage and structure damage. At the same time, certain active metal components (such as V, Fe, Mn, etc.) are prone to sulfidation in the presence of SO2, forming metal sulfides with poor thermal stability and low activity, which further inhibits the occurrence of reduction reactions. Especially in the typical ultra-low temperature flue gas window of 80-300℃, the catalyst is easily exposed to a high-humidity sulfur-containing environment for a long time, which can accelerate the deactivation process of "sulfate deposition-active site closure-reaction migration blocked".

[0004] To improve the running stability of the catalyst in the ultra-low temperature high-humidity sulfur-containing flue gas environment, researchers have tried to introduce a series of sulfur-resistant active components and structure regulation strategies. For example, CN111715230B discloses a thin-walled plate type low-temperature sulfur-resistant SCR denitration catalyst, which enhances the redox capacity and acid-base balance characteristics of the catalyst by introducing Mo and Ce modification components in the TiO2 matrix, and adopts a plate structure to improve the anti-carbon deposition capacity. The catalyst exhibits good NO xconversion performance and certain sulfur resistance. However, its deficiency lies in that the flat plate structure has limited specific surface area per unit and weak dust accumulation resistance, and boundary layer accumulation is easy to form in actual flue gas, affecting the long-term operation efficiency. For example, CN108927170B proposes to prepare a low-temperature denitration catalyst by using CoMnAl hydrotalcite as a precursor, and the sulfur resistance performance is improved by the synergistic effect of the layered structure of hydrotalcite and multiple metals. The catalyst can still maintain high activity under low temperature and high SO2 concentration conditions, showing good sulfur resistance performance. However, the active components of this kind of material are easy to be unevenly precipitated after heat treatment, resulting in insufficient microstructure stability, and the layered structure is easy to be exfoliated or agglomerated under the disturbance of industrial flue gas, reducing the effective service life.

[0005] In summary, although various technical solutions have made certain progress in the field of low-temperature sulfur-resistant SCR, there are still shortcomings such as insufficient structure flux, poor microstructure stability, complex process and difficult industrialization, and it is still difficult to fully meet the stable denitration demand under the condition of ultra-low temperature and high-sulfur flue gas. Therefore, developing a new type of ultra-low-temperature denitration catalyst with high activity, strong sulfur resistance, structural stability and process feasibility is a key technical direction that needs to be broken through in this field. SUMMARY

[0006] To solve the above technical problems, the present application provides a Mn-Me-Ti composite oxide powder and a preparation method thereof. The Mn-Me-Ti composite oxide has a hollow mesoporous structure, which provides a high specific surface area and a short diffusion path, which is beneficial to the mass transfer and adsorption of ultra-low temperature NH3-SCR reactants.

[0007] The technical problem to be solved by the present application is to provide a sulfur-resistant denitration catalyst and a preparation method thereof. The catalyst is suitable for 80-300℃ ultra-low temperature sulfur-containing flue gas environment, has good NO x removal efficiency and SO2 poisoning resistance, and is suitable for flue gas treatment in steel, coking, cement and other industries.

[0008] To achieve the above purpose, the present application adopts the following technical solutions:

[0009] A Mn-Me-Ti composite oxide powder, wherein the Mn-Me-Ti composite oxide powder has a hollow mesoporous structure, and the specific surface area of the Mn-Me-Ti composite oxide powder is 150-300 m 2 / g; wherein Me is Ce, Sn, Sm or Y.

[0010] The preparation method of the above-mentioned Mn-Me-Ti composite oxide powder comprises the following steps:

[0011] S01: an alcohol solution of a titanium source, a manganese salt and a Me salt is mixed with a complexing agent to obtain a precursor solution; the molar ratio of the titanium source, the manganese salt and the Me salt is 1:0.1-0.3:0.01-0.05; the titanium source is tetrabutyl titanate or isopropyl titanate, the manganese salt is manganese nitrate or manganese acetate, the Me salt is one of soluble salts of cerium, tin, samarium or yttrium, and the complexing agent is citric acid or EDTA.

[0012] S02: the precursor solution is added to a basic micellar solution constructed by cetyltrimethylammonium bromide (CTAB) to generate a precipitate under stirring and heating;

[0013] S03: after aging, centrifugation, washing and drying treatment, the precipitate is subjected to calcination to obtain the Mn-Me-Ti composite oxide powder.

[0014] In step S02, the pH of the CTAB-constructed basic micellar solution is 8-10, and the reaction temperature is 40-70°C.

[0015] And / or, the addition rate of the precursor solution is 0.5-2 mL per minute.

[0016] In step S03, the aging time is 12-36 hours.

[0017] And / or, the drying temperature is 80-120°C, and the drying time is 12-24 hours.

[0018] And / or, the calcination temperature is 450-600°C, and the calcination time is 2-5 hours.

[0019] And / or, the heating rate of the calcination in step S03 is 2-5 ℃ / min.

[0020] A preparation method of a sulfur-resistant denitration catalyst, comprising the following steps:

[0021] S1: an active component and an additive are mixed in a certain proportion, and water is added to form a slurry; wherein the water addition amount in the slurry is 20-40% of the mass of the active component, and the additive addition amount is 17.4-56% of the mass of the active component; the active component comprises the above-mentioned Mn-Me-Ti composite oxide powder, a sulfur-resistant additive and a molecular sieve, and the mass ratio of the Mn-Me-Ti composite oxide powder, the sulfur-resistant additive and the molecular sieve is 2-4:1-2:4-8;

[0022] S2: the slurry is subjected to vacuum mud refining and extrusion molding to obtain a catalyst blank;

[0023] S3: drying and calcination treatment of the catalyst blank to obtain the sulfur-resistant denitration catalyst.

[0024] In step S1, the additive further comprises one or more of the following components: 10-25% polyvinyl alcohol, 10-25% sodium polyacrylate, 3-10% pseudo-boehmite, 3-10% kaolin, 3-8% nitric acid, 3-8% hydrochloric acid, 3-8% acetic acid, 1-8% methyl cellulose, 1-8% hydroxypropyl methyl cellulose, 0.1-2% stearic acid, 0.1-2% talc, 0.1-2% paraffin wax, 0.3-3% glycerol, 0.3-3% polyethylene glycol, 0.3-3% propylene glycol. Preferably, the additive comprises the following components: 10-25% polyvinyl alcohol and / or sodium polyacrylate, 3-10% pseudo-boehmite and / or kaolin, 3-8% nitric acid and / or hydrochloric acid and / or acetic acid, 1-8% methyl cellulose and / or hydroxypropyl methyl cellulose, 0.1-2% stearic acid and / or talc and / or paraffin wax, 0.3-3% glycerol and / or polyethylene glycol and / or propylene glycol.

[0025] In step S3, the drying temperature is 40-120℃, and the drying time is 6-14 hours; the calcination temperature is 500-600℃, and the calcination time is 2-6 hours.

[0026] In step S3, the drying treatment is a segmented drying treatment, specifically, 40-60℃ for 2-4 hours in the first stage and 80-120℃ for 4-10 hours in the second stage.

[0027] In step S3, the calcination treatment has a heating rate of 1-5℃ / min.

[0028] The sulfur-resistant additive is MoO3 nanobelt powder. The MoO3 nanobelt powder can be prepared by the existing method, the hydrothermal method in the present application, or other methods. The preparation method of the MoO3 nanobelt in the present application is as follows: disperse molybdenum powder in an aqueous system, form a reactive molybdenum precursor in the presence of an oxidizing agent, uniformly stir, and then perform hydrothermal treatment to promote the ordered crystallization of molybdenum species. The obtained solid is separated, washed, and dried, and then calcined to obtain MoO3 nanobelt. The oxidizing agent is hydrogen peroxide, the hydrothermal temperature is 180-240℃, the reaction time is 24-48 hours, the drying temperature is 80-120℃, the drying time is 12-24 hours, and the obtained product is calcined at 400-550℃ to obtain MoO3 nanobelt.

[0029] The molecular sieve is HY molecular sieve.

[0030] The application discloses a sulfur-resistant denitration catalyst prepared by the preparation method of the sulfur-resistant denitration catalyst.

[0031] The application has the following beneficial effects:

[0032] (1) The hollow mesoporous structure of the Mn-Me-Ti composite oxide powder has a significant activity advantage in ultra-low-temperature denitration. The Mn-Me-Ti composite oxide with a hollow mesoporous structure is constructed by combining a CTAB soft template method with a sol-gel and hydrothermal process. The structure provides a high specific surface area and a short diffusion path, is beneficial to mass transfer and adsorption of an ultra-low-temperature NH3-SCR reactant, and effectively promotes decomposition of a by-product NH4HSO4 (ABS) and relieves a pore blockage problem, thereby significantly improving denitration activity and sulfur resistance stability of the catalyst in an ultra-low-temperature range.

[0033] (2) In the sulfur-resistant denitration catalyst, the Mn-Me-Ti composite oxide is a main denitration active component, the hollow structure provides a high specific surface area and good gas diffusion conditions, the MoO3 nanobelt is used as a sulfur-resistant additive and effectively inhibits SO2 poisoning and sulfate deposition, and the carrier component and the auxiliary additive are used to cooperatively control forming performance and thermal stability. The catalyst has good ultra-low-temperature NO x conversion efficiency and sulfur resistance under typical industrial conditions, is suitable for various complex flue gas treatment scenes, and has a wide application prospect.

[0034] (3) The sulfur-resistant denitration catalyst is added with a sulfur-resistant additive and can effectively prevent sulfur poisoning of the catalyst. The alpha-MoO3 nanobelt prepared by the hydrothermal oxidation method has a layered crystal structure, and a sheet layer spacing can accommodate intercalation of NH4 + Researches show that NH4 + in the ABS can be preferentially inserted into the MoO3 interlayer, and HSO4 - is spatially separated, thereby promoting decomposition of the ABS and participating in the NH3-SCR reaction, realizing a synergistic sulfur resistance mechanism of "self-dissociation and self-removal", and effectively avoiding deposition and passivation of the ABS on the catalyst surface.

[0035] (4) The HY molecular sieve of the present application has excellent ABS capture capacity and acid regulation capacity, further improving the catalytic stability and ultralow-temperature activity. The HY molecular sieve introduced in the present application has a developed microporous structure and rich framework aluminic sites, which can efficiently capture the ABS precursors generated in the gas phase, preventing them from depositing on the active sites, thereby delaying the deactivation of the catalyst. In addition, the Brønsted acid sites of the HY molecular sieve help to enhance the adsorption and activation of NH3, improving the denitration reaction efficiency under ultralow-temperature conditions. Studies have shown that the ABS adsorption capacity of the HY molecular sieve is strong, and the regeneration performance is good, which is an effective additive for improving the sulfur resistance and cycle stability of the catalyst. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0037] Unless otherwise specified, the raw materials used in the following examples are commercially available.

[0038] The sulfur-resistant denitration catalyst of the present application is especially suitable for NO x removal under the condition of ultralow-temperature sulfur-containing flue gas. The catalyst takes hollow structure Mn-Me-Ti composite oxide as the main active component, supplemented by MoO3 nanobelt as a sulfur-resistant additive, and introduces HY molecular sieve to regulate the acidity and pore structure. Its preparation includes: synthesizing hollow structure Mn-Me-Ti oxide by sol-gel and CTAB template method; preparing MoO3 nanobelt by hydrothermal method; then mixing with molecular sieve and various additives, pulping, extruding, drying and calcining to obtain a stable strip-shaped catalyst. The catalyst has good ultralow-temperature denitration performance and sulfur poisoning resistance, and is suitable for flue gas treatment in steel, coking and other industries.

[0039] Example 1

[0040] First part: preparation of Mn-Me-Ti composite oxide powder.

[0041] S01: tetrabutyl titanate, manganese nitrate and tin chloride were dissolved in anhydrous ethanol according to the molar ratio of 1:0.2:0.02, and citric acid was added as a complexing agent to prepare a precursor solution;

[0042] S02: The precursor solution was added to the CTAB constructed basic micellar solution at a rate of 1 mL / min, the pH was controlled at 9, and the reaction temperature was maintained at 60 ℃. After the reaction was completed, a precipitate was obtained;

[0043] S03: The obtained precipitate of step S02 is aged for 24 hours, then separated by centrifugation, washed, dried at 80℃ for 12 hours, and then calcined at 500℃ for 4 hours with a temperature rising rate of 3 ℃ / min, to obtain Mn-Me-Ti composite oxide powder.

[0044] Second part: Preparation of sulfur-resistant additive MoO3 nanobelt.

[0045] The metal molybdenum powder is dispersed in water, hydrogen peroxide is added to form a molybdenum precursor, and the obtained solid is separated, washed and dried, and then calcined at 450℃ for 2 hours, to obtain MoO3 nanobelt.

[0046] Third part: Preparation of sulfur-resistant denitration catalyst.

[0047] S1: 30 parts of the obtained Mn-Me-Ti composite oxide, 10 parts of MoO3 nanobelt and 60 parts of HY molecular sieve (mass ratio 3:1:6) are mixed to obtain a total of 100 parts of mixture; 20 parts of polyvinyl alcohol, 5 parts of pseudo-boehmite, 5 parts of nitric acid, 4 parts of methyl cellulose, 0.5 parts of stearic acid, 1 part of glycerol and 30 parts of deionized water are added to the above mixture to obtain a slurry;

[0048] S2: The slurry is vacuumed and then extruded to obtain a catalyst blank;

[0049] S3: The catalyst blank obtained in S2 is dried at 60℃ for 3 hours, dried at 100℃ for 6 hours, and then calcined at 550℃ for 4 hours with a temperature rising rate of 3 ℃ / min, to obtain a sulfur-resistant denitration catalyst.

[0050] Example 2

[0051] First part: Preparation of Mn-Me-Ti composite oxide powder.

[0052] S01: Isopropyl titanate, manganese acetate and cerium nitrate are dissolved in n-propanol according to a molar ratio of 1:0.3:0.03, and EDTA is added as a complexing agent to prepare a precursor solution;

[0053] S02: The precursor solution is added to the CTAB constructed basic micellar solution at a rate of 0.8 mL / min, the pH is controlled at 10, and the reaction temperature is maintained at 40℃. After the reaction is completed, a precipitate is obtained;

[0054] S03: The precipitate obtained in step S02 is aged for 18 hours, then separated by centrifugation, washed, dried at 100℃ for 18 hours, and then calcined at 450℃ for 3 hours with a temperature rising rate of 2 ℃ / min, to obtain Mn-Me-Ti composite oxide powder.

[0055] Second part: Preparation of sulfur-resistant additive MoO3 nanobelt.

[0056] The metal molybdenum powder is dispersed in water, hydrogen peroxide is added to form a molybdenum precursor, the obtained solid is separated, washed and dried, and then calcined at 500 ℃ for 2 hours to obtain MoO3 nanobelt.

[0057] The third part is to prepare a sulfur-resistant denitration catalyst.

[0058] S1: 40 parts of the obtained Mn-Me-Ti composite oxide, 20 parts of MoO3 nanobelt and 40 parts of HY molecular sieve (mass ratio 4:2:4) are mixed to obtain a total of 100 parts of mixture. 15 parts of polyvinyl alcohol, 7 parts of pseudo-boehmite, 8 parts of nitric acid, 6 parts of methyl cellulose, 1.5 parts of stearic acid, 2 parts of glycerol and 25 parts of deionized water are added to 100 parts of the above mixture to obtain a slurry;

[0059] S2: the slurry is vacuumed and then extruded to obtain a catalyst blank;

[0060] S3: the catalyst blank obtained in S2 is dried at 60 ℃ for 4 hours, dried at 120 ℃ for 5 hours, then heated to 500 ℃ at a rate of 2 ℃ / min and calcined for 5 hours to obtain a sulfur-resistant denitration catalyst.

[0061] Example 3

[0062] The first part is to prepare a Mn-Me-Ti composite oxide powder.

[0063] S01: tetrabutyl titanate, manganese nitrate and tin chloride are dissolved in anhydrous ethanol according to a molar ratio of 1:0.15:0.015, and citric acid is added as a complexing agent to prepare a precursor solution;

[0064] S02: the precursor solution is added to the CTAB constructed basic micellar solution at a rate of 2 mL / min, the pH is controlled at 8, and the reaction temperature is maintained at 70 ℃. After the reaction is completed, a precipitate is obtained;

[0065] S03: the precipitate obtained in step S02 is aged for 12 hours, then separated by centrifugation, washed, dried at 120 ℃ for 20h, then heated to 600 ℃ at a rate of 5 ℃ / min and calcined for 2 hours to obtain a Mn-Me-Ti composite oxide powder.

[0066] The second part is to prepare a sulfur-resistant aid MoO3 nanobelt.

[0067] The metal molybdenum powder is dispersed in water, hydrogen peroxide is added to form a molybdenum precursor, the obtained solid is separated, washed and dried, and then calcined at 500 ℃ for 2 hours to obtain MoO3 nanobelt.

[0068] Third part: preparation of sulfur-resistant denitration catalyst.

[0069] S1: 20 parts of the obtained Mn-Me-Ti composite oxide, 20 parts of MoO3 nanobelt and 60 parts of HY molecular sieve (mass ratio 2:2:6) were mixed to obtain a mixture of 100 parts; 25 parts of polyvinyl alcohol, 10 parts of pseudo-boehmite, 8 parts of nitric acid, 3 parts of methyl cellulose, 2 parts of stearic acid, 3 parts of glycerol and 40 parts of deionized water were added to 100 parts of the above mixture to obtain a slurry;

[0070] S2: The slurry obtained in step S1 was vacuumed and then extruded to obtain a catalyst blank;

[0071] S3: The catalyst blank obtained in step S2 was dried at 60 ℃ for 4 hours, dried at 100 ℃ for 4 hours, then heated to 600 ℃ at a rate of 1 ℃ / min and calcined for 6 hours to obtain a sulfur-resistant denitration catalyst.

[0072] Example 4

[0073] First part: preparation of Mn-Me-Ti composite oxide powder.

[0074] S01: Isopropyl titanate, manganese acetate and samarium nitrate were dissolved in anhydrous ethanol according to a molar ratio of 1:0.1:0.01, and citric acid was added as a complexing agent to prepare a precursor solution;

[0075] S02: The precursor solution was added to the CTAB constructed basic micellar solution at a rate of 1.5 mL / min, the pH was controlled at 9, and the reaction temperature was maintained at 55 ℃. After the reaction was completed, a precipitate was obtained;

[0076] S03: The precipitate obtained in step S02 was aged for 36 hours, then centrifuged, washed, dried at 80 ℃ for 24 hours, then heated to 550 ℃ at a rate of 3 ℃ / min and calcined for 3 hours to obtain Mn-Me-Ti composite oxide powder.

[0077] Second part: preparation of sulfur-resistant additive MoO3 nanobelt.

[0078] Metallic molybdenum powder was dispersed in water, hydrogen peroxide was added to form a molybdenum precursor, and the obtained solid was separated, washed and dried, then calcined at 500 ℃ for 2 hours to obtain MoO3 nanobelt.

[0079] Third part: preparation of sulfur-resistant denitration catalyst.

[0080] S1: 30 parts of the obtained Mn-Me-Ti composite oxide, 10 parts of MoO3 nanobelt and 50 parts of HY molecular sieve (mass ratio 4:1:5) were mixed to obtain a total of 100 parts of mixture; 20 parts of polyvinyl alcohol, 6 parts of pseudoboehmite, 4 parts of nitric acid, 5 parts of methyl cellulose, 0.1 parts of stearic acid, 0.5 parts of glycerol and 35 parts of deionized water were added to 100 parts of the above mixture to obtain a slurry;

[0081] S2: The slurry obtained in step S1 was vacuumed and then extruded to obtain a catalyst blank;

[0082] S3: The catalyst blank obtained in step S2 was dried at 60 ℃ for 3 hours, dried at 80 ℃ for 8 hours, then heated to 500 ℃ at a rate of 4 ℃ / min and calcined for 3 hours to obtain a sulfur-resistant denitration catalyst.

[0083] Example 5

[0084] First part: preparation of Mn-Me-Ti composite oxide powder.

[0085] S01: Tetrabutyl titanate, manganese nitrate and yttrium nitrate were dissolved in anhydrous ethanol according to a molar ratio of 1:0.25:0.05, and citric acid was added as a complexing agent to prepare a precursor solution;

[0086] S02: The precursor solution was added to the CTAB-constructed basic micellar solution at a rate of 0.5 mL / min, the pH was controlled at 10, and the reaction temperature was maintained at 65 ℃. After the reaction was completed, a precipitate was obtained;

[0087] S03: The precipitate obtained in step S02 was aged for 24 hours, then centrifuged, washed, dried at 90 ℃ for 20 hours, then heated to 600 ℃ at a rate of 4 ℃ / min and calcined for 5 hours to obtain Mn-Me-Ti composite oxide powder.

[0088] Second part: preparation of sulfur-resistant additive MoO3 nanobelt.

[0089] Metallic molybdenum powder was dispersed in water, hydrogen peroxide was added to form a molybdenum precursor, and hydrothermal treatment was carried out at 180 ℃ for 48 hours. The obtained solid was separated, washed and dried, and then calcined at 550 ℃ for 2 hours to obtain MoO3 nanobelt.

[0090] Third part: preparation of sulfur-resistant denitration catalyst.

[0091] S1: 30 parts of the obtained Mn-Me-Ti composite oxide, 20 parts of MoO3 nanobelt and 50 parts of HY molecular sieve (mass ratio 3:2:5) were mixed to obtain 100 parts of a mixture; 10 parts of polyvinyl alcohol, 4 parts of pseudoboehmite, 3 parts of nitric acid, 2 parts of methyl cellulose, 1 part of stearic acid, 2.5 parts of glycerol and 28 parts of deionized water were added to 100 parts of the above mixture to obtain a slurry;

[0092] S2: The slurry obtained in step S1 was subjected to vacuum pugging and then extrusion molding to obtain a catalyst blank;

[0093] S3: The catalyst blank obtained in step S2 was dried at 60 ℃ for 3 hours and at 100 ℃ for 6 hours, then heated to 500 ℃ at a rate of 3 ℃ / min and calcined for 4 hours to obtain a sulfur-resistant denitration catalyst.

[0094] Example 6

[0095] First part: Preparation of Mn-Me-Ti composite oxide powder.

[0096] S01: Titanium isopropylate, manganese acetate and samarium nitrate were dissolved in anhydrous ethanol according to a molar ratio of 1:0.2:0.04, and EDTA was added as a complexing agent to prepare a precursor solution;

[0097] S02: The precursor solution was added dropwise to a CTAB-constructed basic micellar solution at a rate of 1 mL / min, the pH was controlled at 9, and the reaction temperature was maintained at 50 ℃. After the reaction was completed, a precipitate was obtained;

[0098] S03: The precipitate obtained in step S02 was aged for 30 hours, then centrifuged, washed, dried at 90 ℃ for 12 hours, heated to 550 ℃ at a rate of 2 ℃ / min and calcined for 5 hours to obtain Mn-Me-Ti composite oxide powder.

[0099] Second part: Preparation of sulfur-resistant additive MoO3 nanobelt.

[0100] Metallic molybdenum powder was dispersed in water, hydrogen peroxide was added to form a molybdenum precursor, and the mixture was subjected to hydrothermal treatment at 200 ℃ for 24 hours. The obtained solid was separated, washed and dried, and then calcined at 500 ℃ for 2 hours to obtain MoO3 nanobelt.

[0101] Third part: Preparation of sulfur-resistant denitration catalyst.

[0102] S1: 30 parts of the obtained Mn-Me-Ti composite oxide, 15 parts of MoO3 nanobelt and 55 parts of HY molecular sieve (mass ratio 3:1.5:5.5) were mixed to obtain a mixture of a total of 100 parts; 22 parts of polyvinyl alcohol, 8 parts of pseudoboehmite, 5 parts of nitric acid, 7 parts of methyl cellulose, 1.2 parts of stearic acid, 1.5 parts of glycerol and 33 parts of deionized water were added to 100 parts of the above mixture to obtain a slurry;

[0103] S2: After vacuum refining of the slurry, the catalyst blank was extruded to obtain a catalyst blank;

[0104] S3: After drying the catalyst blank at 40 ℃ for 3 hours and at 90 ℃ for 6 hours, the temperature was raised to 550 ℃ at a rate of 5 ℃ / min and calcined for 3 hours to obtain a sulfur-resistant denitration catalyst.

[0105] Example 7

[0106] First part: preparation of Mn-Me-Ti composite oxide powder.

[0107] S01: Titanium isopropylate, manganese acetate and samarium nitrate were dissolved in anhydrous ethanol according to a molar ratio of 1:0.2:0.04, and EDTA was added as a complexing agent to prepare a precursor solution;

[0108] S02: The precursor solution was added dropwise to the CTAB-constructed basic micellar solution at a rate of 1 mL / min, the pH was controlled at 9, and the reaction temperature was maintained at 50 ℃. After the reaction was completed, a precipitate was obtained;

[0109] S03: The precipitate obtained in step S02 was aged for 30 hours, then centrifuged, washed, dried at 90 ℃ for 12 hours, and then calcined at 550 ℃ at a rate of 2 ℃ / min for 5 hours to obtain Mn-Me-Ti composite oxide powder.

[0110] Second part: preparation of sulfur-resistant additive MoO3 nanobelt.

[0111] Metallic molybdenum powder was dispersed in water, hydrogen peroxide was added to form a molybdenum precursor, and hydrothermal treatment was carried out at 200 ℃ for 24 hours. The obtained solid was separated, washed and dried, and then calcined at 500 ℃ for 2 hours to obtain MoO3 nanobelt.

[0112] Third part: preparation of sulfur-resistant denitration catalyst.

[0113] S1: 20 parts of the obtained Mn-Me-Ti composite oxide, 20 parts of MoO3 nanobelt and 80 parts of HY molecular sieve (mass ratio 2:2:8) were mixed to obtain a mixture of 120 parts in total; 12 parts of sodium polyacrylate, 18 parts of polyvinyl alcohol, 12 parts of kaolin, 9.6 parts of hydrochloric acid, 9.6 parts of hydroxypropyl methyl cellulose, 2.4 parts of paraffin, 3.6 parts of propylene glycol and 48 parts of deionized water were added to the above-mentioned mixture of 120 parts in a mass fraction ratio to obtain a slurry;

[0114] S2: After vacuuming the slurry, the catalyst blank was extruded to obtain a catalyst blank;

[0115] S3: After drying the catalyst blank at 50 ℃ for 2 hours and at 90 ℃ for 10 hours, the temperature was raised to 550 ℃ at a rate of 5 ℃ / min and calcined for 3 hours to obtain a sulfur-resistant denitration catalyst.

[0116] Example 8

[0117] First part: preparation of Mn-Me-Ti composite oxide powder.

[0118] S01: titanium isopropylate, manganese acetate and samarium nitrate were dissolved in anhydrous ethanol in a molar ratio of 1:0.2:0.04, and EDTA was added as a complexing agent to prepare a precursor solution;

[0119] S02: The precursor solution was added to the CTAB constructed basic micellar solution at a rate of 1 mL / min, the pH was controlled at 9, and the reaction temperature was maintained at 50 ℃. After the reaction was completed, a precipitate was obtained;

[0120] S03: The precipitate obtained in step S02 was aged for 30 hours, then centrifuged, washed, dried at 90 ℃ for 12 hours, and then calcined at 550 ℃ at a rate of 2 ℃ / min for 5 hours to obtain Mn-Me-Ti composite oxide powder.

[0121] Second part: preparation of sulfur-resistant additive MoO3 nanobelt.

[0122] Metallic molybdenum powder was dispersed in water, hydrogen peroxide was added to form a molybdenum precursor, and the mixture was hydrothermally treated at 200 ℃ for 24 hours. The obtained solid was separated, washed and dried, and then calcined at 500 ℃ for 2 hours to obtain MoO3 nanobelt.

[0123] Third part: preparation of sulfur-resistant denitration catalyst.

[0124] S1: 30 parts of the obtained Mn-Me-Ti composite oxide, 20 parts of MoO3 nanobelt and 50 parts of HY molecular sieve (mass ratio 3:2:5) were mixed to obtain a mixture of a total of 100 parts; 15 parts of sodium polyacrylate, 3 parts of kaolin, 5 parts of acetic acid, 1 part of hydroxypropyl methyl cellulose, 0.1 part of talc, 0.3 part of polyethylene glycol and 40 parts of deionized water were added to 100 parts of the above mixture to obtain a slurry;

[0125] S2: After vacuum refining of the slurry, extrusion molding was performed to obtain a catalyst blank;

[0126] S3: After drying at 50 ℃ for 3 hours and at 90 ℃ for 6 hours, the catalyst blank was calcined at 5 ℃ / min to 550 ℃ for 3 hours to prepare a sulfur-resistant denitration catalyst.

[0127] Comparative Example 1

[0128] First, isopropyl titanate, manganese acetate and tin chloride were dissolved in anhydrous ethanol at a molar ratio of 1:0.2:0.04, and EDTA was added as a complexing agent to prepare a precursor solution. Under magnetic stirring at room temperature, the reaction was carried out for 6 hours, and then the obtained solution was continuously stirred at 80 ℃ water bath for 4 hours. After the reaction was completed, the system was aged for 30 hours. The obtained precipitate was separated by centrifugation, washed and dried, and then calcined at 2 ℃ / min to 550 ℃ for 5 hours to obtain Mn-Me-Ti composite oxide powder.

[0129] Subsequently, metal molybdenum powder was dispersed in water, and hydrogen peroxide was added to form a molybdenum precursor. The obtained solid was separated, washed and dried, and then calcined at 500 ℃ for 2 hours to obtain MoO3 nanobelt.

[0130] The obtained Mn-Me-Ti composite oxide, MoO3 nanobelt and HY molecular sieve were mixed at a mass ratio of 3:1.5:5.5. 100 parts of the above mixture was added with 22 parts of polyvinyl alcohol, 8 parts of pseudo-boehmite, 5 parts of nitric acid, 7 parts of methyl cellulose, 1.2 parts of stearic acid, 1.5 parts of glycerol and 33 parts of deionized water, and then vacuum refining and extrusion molding were performed. After drying at 60 ℃ for 3 hours and at 90 ℃ for 6 hours, calcination was performed at 2 ℃ / min to 550 ℃ for 3 hours to prepare a sulfur-resistant denitration catalyst.

[0131] Comparative Example 2

[0132] Firstly, isopropyl titanate, manganese acetate and tin chloride were dissolved in anhydrous ethanol according to the molar ratio of 1:0.2:0.04, and EDTA was added as a complexing agent to prepare a precursor solution. The precursor solution was added to the CTAB constructed basic micellar solution at a rate of 1 mL / min, the pH was controlled at 9, the reaction temperature was maintained at 50 ℃, and after the reaction was completed, it was aged for 30 hours. The obtained precipitate was separated by centrifugation, washed, dried, and then heated to 550 ℃ at a rate of 2 ℃ / min for 5 hours to obtain Mn-Me-Ti hollow oxide powder.

[0133] The obtained Mn-Me-Ti composite oxide was mixed with MoO3 nanobelt according to the mass ratio of 3:1.5. 100 parts of the above mixture were added with 22 parts of polyvinyl alcohol, 8 parts of pseudo-boehmite, 5 parts of nitric acid, 7 parts of methyl cellulose, 1.2 parts of stearic acid, 1.5 parts of glycerol and 33 parts of deionized water, and then extruded into a shape after vacuuming. After drying at 60 ℃ for 3 hours and 90 ℃ for 6 hours, it was heated to 550 ℃ at a rate of 2 ℃ / min for 3 hours to prepare a sulfur-resistant denitration catalyst.

[0134] Comparative Example 3

[0135] Firstly, isopropyl titanate, manganese acetate and tin chloride were dissolved in anhydrous ethanol according to the molar ratio of 1:0.2:0.04, and EDTA was added as a complexing agent to prepare a precursor solution. The precursor solution was added to the CTAB constructed basic micellar solution at a rate of 1 mL / min, the pH was controlled at 9, the reaction temperature was maintained at 50 ℃, and after the reaction was completed, it was aged for 30 hours. The obtained precipitate was separated by centrifugation, washed, dried, and then heated to 550 ℃ at a rate of 2 ℃ / min for 5 hours to obtain Mn-Me-Ti hollow oxide powder.

[0136] The obtained Mn-Me-Ti composite oxide was mixed with HY molecular sieve according to the mass ratio of 3:5.5. 100 parts of the above mixture were added with 22 parts of polyvinyl alcohol, 8 parts of pseudo-boehmite, 5 parts of nitric acid, 7 parts of methyl cellulose, 1.2 parts of stearic acid, 1.5 parts of glycerol and 33 parts of deionized water, and then extruded into a shape after vacuuming. After drying at 60 ℃ for 3 hours and 90 ℃ for 6 hours, it was heated to 550 ℃ at a rate of 2 ℃ / min for 3 hours to prepare a sulfur-resistant denitration catalyst.

[0137] Catalyst denitration activity test

[0138] The activity test of the ultra-low temperature denitration catalyst prepared in the above examples and comparative examples was completed on a fixed bed reactor, the reaction temperature was 80-300 ℃, the simulated flue gas was 1000 ppm NH3+1000 ppm NO+200 ppm SO2+5v.%H2O+5% O2, N2 was balanced, the pressure was normal pressure, and the space velocity was 30000 h-1. The reaction activity of the catalyst was determined by conversion rate of NO, and the tail gas was analyzed by KM9506 smoke analyzer, and the results are shown in Table 1.

[0139] Table 1. Catalyst reaction activity results of examples 1-8 and comparative examples 1-3

[0140]

[0141] As can be seen from Table 1, the catalysts prepared in examples 1-8 all exhibit excellent denitration activity in the ultra-low temperature range of 80-300℃, which is mainly due to the synergistic effect between the high specific surface area structure of Mn-Me-Ti hollow oxide, the redox auxiliary role of MoO3 nanobelt and the acid regulation and gas diffusion auxiliary function of HY molecular sieve. In contrast, the Mn-Me-Ti solid structure active powder prepared by the traditional coprecipitation method in comparative example 1 lacks the specific surface area advantage and active site exposure degree brought by the hollow structure, resulting in its NO conversion rate being lower than that of the examples at each test temperature, especially in the ultra-low temperature range of 80-160℃, the activity degradation is more obvious; and comparative example 2 and comparative example 3 do not introduce HY molecular sieve and MoO3 respectively, and lack of oxidation-reduction boost and acid regulation mechanism, its denitration sulfur resistance is weak, and the NO conversion rate at 80-300℃ is less than 85%, further verifying the necessity and superiority of multi-component construction.

[0142] In summary, the synergistic design of MoO3 nanobelt, HY molecular sieve and hollow structure Mn-Me-Ti active oxide in the present application is the key to improving the low-temperature denitration activity and sulfur resistance of the catalyst.

[0143] Those skilled in the art will readily understand that the above description is only a preferred embodiment of the present application and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0144] The part of the present application specification not described in detail belongs to the known technology in the art, and the above examples are only for the purpose of describing the present application, and are not intended to limit the scope of the present application. The scope of the present application is defined by the appended claims. Any equivalent replacement and modification made without departing from the spirit and principle of the present application shall be included in the scope of the present application.

Claims

1. A Mn-Me-Ti composite oxide powder, characterized in that, The Mn-Me-Ti composite oxide powder has a hollow mesoporous structure, and a specific surface area of the Mn-Me-Ti composite oxide powder is ; wherein Me is Ce, Sn, Sm, or Y.

2. The method of producing the Mn-Me-Ti composite oxide powder according to claim 1, characterized by, The method comprises the following steps: S01: mixing an alcohol solution of a titanium source, a manganese salt and a Me salt with a complexing agent to obtain a precursor solution; the molar ratio of the titanium source, the manganese salt and the Me salt is 1:0.1-0.3:0.01-0.05; the titanium source is tetrabutyl titanate or isopropyl titanate, the manganese salt is manganese nitrate or manganese acetate, the Me salt is one of soluble salts of cerium, tin, samarium or yttrium, and the complexing agent is citric acid or EDTA; S02: adding the precursor solution into a CTAB-constructed basic micellar solution to generate a precipitate under stirring and heating; S03: performing aging, centrifugation, washing and drying treatment on the precipitate, and then performing calcination treatment to obtain the Mn-Me-Ti composite oxide powder.

3. The method of producing the Mn-Me-Ti composite oxide powder according to claim 2, wherein In step S02, the pH of the CTAB-constructed basic micellar solution is 8-10, and the reaction temperature is 40-70 DEG C. And / or, the adding rate of the precursor solution is 0.5-2 mL per minute.

4. The method of producing the Mn-Me-Ti composite oxide powder according to claim 2, wherein In step S03, the aging treatment time is 12-36 hours. And / or, the drying treatment temperature is 80-120 DEG C, and the drying treatment time is 12-24 hours. And / or, the calcination treatment temperature is 450-600 DEG C, and the calcination treatment time is 2-5 hours. And / or, the temperature increasing rate of the calcination treatment in step S03 is .

5. A method for producing a sulfur-tolerant de-NOx catalyst, characterized by, The method comprises the following steps: S1: mixing active components and additives according to a certain proportion, and adding water to form a slurry; wherein the water addition amount in the slurry is 20-40% of the mass of the active components, and the additive addition amount is 17.4-56% of the mass of the active components; the active components comprise the Mn-Me-Ti composite oxide powder, a sulfur-resistant additive and a molecular sieve, and the mass ratio of the Mn-Me-Ti composite oxide powder, the sulfur-resistant additive and the molecular sieve is 2-4:1-2:4-8; S2: performing vacuum mud conditioning and extrusion molding treatment on the slurry to obtain a catalyst blank; S3: performing drying and calcination treatment on the catalyst blank to obtain the sulfur-resistant de-NOx catalyst.

6. The method for preparing the sulfur-resistant denitrification catalyst according to claim 5, characterized in that, In step S1, the additives further comprise one or more of the following components: 10-25% of polyvinyl alcohol, 10-25% of sodium polyacrylate, 3-10% of pseudo-boehmite, 3-10% of kaolin, 3-8% of nitric acid, 3-8% of hydrochloric acid, 3-8% of acetic acid, 1-8% of methyl cellulose, 1-8% of hydroxypropyl methyl cellulose, 0.1-2% of stearic acid, 0.1-2% of talc, 0.1-2% of paraffin wax, 0.3-3% of glycerol, 0.3-3% of polyethylene glycol, and 0.3-3% of propylene glycol.

7. The method for preparing the sulfur-resistant denitrification catalyst according to claim 5, characterized in that, In step S3, the drying treatment temperature is 40-120 DEG C, the drying treatment time is 6-14 hours, the calcination treatment temperature is 500-600 DEG C, and the calcination treatment time is 2-6 hours.

8. The method for preparing the sulfur-resistant denitrification catalyst according to claim 7, characterized in that, The drying treatment in step S3 is a segmented drying treatment, specifically, a first stage of 40-60 DEG C drying for 2-4 hours, and a second stage of 80-120 DEG C drying for 4-10 hours. And / or, the temperature increasing rate of the calcination treatment in step S3 is .

9. The method of claim 5, wherein the sulfur-oxidizing de-NOx catalyst is prepared by the steps of: preparing a solution of a metal salt of a transition metal and a metal salt of a post-transition metal; mixing the solution with a support; and drying the mixture. The anti-sulfur aid is Nanoribbon powders; And / or, the molecular sieve is a HY molecular sieve.

10. A sulfur-tolerant de-NOx catalyst characterized by, The anti-sulfur denitration catalyst is prepared by the preparation method in any one of claims 5-9.

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