Molecular sieve type high-temperature denitration catalyst as well as preparation method and application thereof
The synthesis of SAPO-18 molecular sieves with controlled morphology and enhanced surface acidity using organic additives addresses the limitations of current SAPO-18 catalysts, achieving efficient high-temperature denitration performance.
Patent Information
- Application Number
- CN202411255997.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2024-12-10
AI Technical Summary
Current SAPO-18 molecular sieves face challenges such as high cost, poor hydrothermal stability, low yield, long crystallization time, and uncontrollable morphology, limiting their application in high-temperature denitration catalysts.
A molecular sieve-type high-temperature denitration catalyst is synthesized using organic phosphoric acid as a morphology regulator, organic amine as an organic template, and quaternary ammonium base as a structure directing agent, employing a hydrothermal organic-inorganic self-assembly method to control morphology and introduce Cu ions, enhancing surface acidity and active sites.
The catalyst exhibits high efficiency in NOx removal at high temperatures with improved yield, surface acidity, and stability, suitable for industrial applications.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of porous inorganic material preparation, and specifically relates to a molecular sieve type high-temperature denitration catalyst and a preparation method and application thereof. Background Art
[0002] With the continuous development of human society, air pollution is becoming increasingly serious. Among them, nitrogen oxides (NO x ) is an important precursor of acid rain, photochemical smog and ozone, and an important component of haze, which seriously threatens people's life and health. x (NH3-SCR) technology can convert it into harmless nitrogen, and catalytically remove NO x The key to the process is the SCR denitrification catalyst. Molecular sieve is a crystalline material with uniform pores / channels and a three-dimensional skeleton. It is widely used in adsorbents, ion exchangers and catalysts due to its shape selectivity. In 1984, scientists from UCC in the United States added silicon sources to the raw materials for synthesizing aluminum phosphate molecular sieves and successfully synthesized aluminum silicophosphate molecular sieves, which were applied in MTO reaction research.
[0003] In recent years, Cu-based small-pore molecular sieve catalysts with CHA and AEI structures, such as Cu-SSZ-13 and Cu-SAPO-18, have been endowed with unique shape selectivity due to their limited microporous structure of molecular size, and have attracted extensive attention for their high catalytic activity, N2 selectivity and stability. However, SSZ-13 molecular sieve has problems such as high cost and poor hydrothermal stability, while SAPO-18 molecular sieve has high hydrothermal stability and has become an important denitration catalyst carrier for SCR denitration. SAPO-18 molecular sieve is composed of SiO4, AlO2 - and PO2 +Tetrahedrons constitute the primary structural unit, which is connected to form secondary structural units such as double six-membered rings (D6R) through the interaction of bridging oxygen bonds, and finally connected to form a three-dimensional pore structure containing eight-membered rings through four-membered rings. The pore size of the three-dimensional eight-membered ring is 0.38nm×0.38nm, and the cage size formed by the double six-membered ring is 1.09nm×0.67nm. In SAPO-18 molecular sieve, there is a certain angle between the two adjacent layers of double six-membered rings, which is formed by two groups of parallel double six-membered rings arranged in a cross-distribution manner, and is pear-shaped. SAPO-18 has the characteristics of large cages and small pores. The larger cage can accommodate the macromolecular substances produced during the reaction, and the smaller pore size limits the diffusion path of the molecular substances in the reaction, which is beneficial to the NH3-SCR performance. The denitrification activity is mainly concentrated in the medium and low temperature range. Moreover, the SAPO-18 molecular sieve prepared by conventional methods has high hydrothermal temperature, long hydrothermal time, low yield, and uncontrollable morphology, large size, and low utilization rate of active area, which seriously affects its application in catalysis. Therefore, how to use SAPO-18 molecular sieve to construct a molecular sieve-type high-temperature deNOx catalyst has become a current challenge for high-temperature deNOx. Summary of the invention
[0004] In view of the shortcomings of the prior art, the present invention provides a molecular sieve type high temperature denitration catalyst. The present invention uses organic phosphoric acid as a morphology regulator, organic amine as an organic template, and quaternary ammonium base as a structure directing agent to synthesize SAPO-18 molecular sieve nanosheets with a layered structure through a hydrothermal organic-inorganic self-assembly method. The synthesized molecular sieve has a high yield. At the same time, the organic phosphoric acid is calcined at a high temperature to produce a mesoporous structure. 2+ After ion exchange, the surface acidity of the catalyst is greatly improved, making the catalyst highly efficient in NO removal under high temperature conditions. x Removal performance.
[0005] To achieve this object, the present invention adopts the following technical solutions:
[0006] In view of the deficiencies in the prior art, the present invention provides a molecular sieve-type high-temperature denitration catalyst and optimizes the synthesis steps. The layered SAPO-18 molecular sieve synthesis method provided by the present invention solves the problems of low product yield, long crystallization time, and difficult morphology control in the current synthesis of SAPO-18 molecular sieves; the SAPO-18 molecular sieve prepared by the present invention can introduce organic phosphoric acid as a morphology directing agent, cooperate with organic templates and structure directing agents, and adjust various control parameters in the synthesis process according to needs through the hydrothermal-self-assembly method to control the morphology, surface acidity, and distribution of Cu ions in the molecular sieve pores of the catalyst, thereby improving the acidity and number of active sites of the catalyst and improving the high-temperature denitration catalytic performance; the SAPO-18 prepared by the present invention has a nanosheet layered morphology, and the Cu-SAPO-18 exchanged by Cu ions can show efficient removal of NO at high temperatures. x performance.
[0007] A method for preparing a molecular sieve type high-temperature denitration catalyst, the preparation method comprising the following steps:
[0008] (1) adding an aluminum source, a silicon source, a phosphorus source and an organic template to a structure directing agent solution in sequence and mixing them uniformly to obtain a hydrothermal precursor;
[0009] (2) placing the hydrothermal precursor obtained in step (1) into a hydrothermal reactor at a hydrothermal temperature of 150-200° C. for a reaction time of 2-5 days, washing and drying the hydrothermal product to obtain a layered SAPO-18 molecular sieve raw powder; (3) calcining the layered SAPO-18 molecular sieve raw powder obtained in step (2) at 500-700° C. for 2-5 hours to obtain a layered SAPO-18 molecular sieve.
[0010] (4) The layered SAPO-18 molecular sieve obtained in step (3) is placed in a copper salt solution for ion exchange at 50-80° C. for 2-6 hours, washed and dried, and then calcined at 500-800° C. for 4-8 hours to obtain a copper ion-type layered SAPO-18 molecular sieve catalyst, i.e., a molecular sieve-type high-temperature denitration catalyst.
[0011] In the technical solution of the present invention: the aluminum source in step (1) is one of pseudo-boehmite and aluminum hydroxide, the silicon source is one of tetraethyl orthosilicate and fumed silica; the phosphorus source is phosphoric acid and hydroxyethylidene diphosphoric acid;
[0012] The organic template is one of triethylamine, morpholine and NN dimethylacetamide; the structure directing agent is one of tetramethylammonium hydroxide and tetraethylammonium hydroxide, and the concentration of the structure directing agent solution is 20-30%.
[0013] In the technical solution of the present invention, the molar ratio of phosphoric acid to hydroxyethylidene diphosphoric acid is 1:0.1-1.
[0014] In the technical solution of the present invention, the molar ratio of phosphoric acid to hydroxyethylidene diphosphoric acid is 1:0.1-0.3.
[0015] In the technical solution of the present invention: the molar ratio of the aluminum source, silicon source, phosphorus source, template and structure directing agent in step (1) is 1: (0.1-2): (0.1-1): (0.1-1): (0.1-1).
[0016] In the technical solution of the present invention: the molar ratio of the aluminum source, silicon source, phosphorus source, template agent and structure directing agent is 1: (0.1-1): (0.2-1): (0.1-0.5): (0.1-1).
[0017] In the technical solution of the present invention, the mass ratio of the layered SAPO-18 molecular sieve to the copper salt solution is 1:40-60, and the concentration of the copper salt solution is 0.1-1M.
[0018] A molecular sieve type high temperature denitration catalyst is prepared by the above method.
[0019] In the technical solution of the present invention, the copper ion type layered SAPO-18 molecular sieve catalyst prepared by the method is used for high-temperature denitration in flue gas.
[0020] In the above applications: NO x The initial concentration is 100-1500ppm, NH3 is 100-1500ppm, O2 concentration is 5-15%, and the air velocity is 40000-60000h -1 , the particle size of the catalyst is 20-40 mesh, and the reaction temperature ranges from 300-750°C.
[0021] Beneficial effects:
[0022] The molecular sieve prepared by the method has a two-dimensional nano-layered structure, which can expose more active sites and is conducive to the mass transfer and diffusion of reactants. At the same time, the catalyst exhibits high surface acidity and high content of catalytic active sites, thereby showing efficient high-temperature denitration performance and stability. The advantages of the present invention are that the method has a simple preparation process, low cost, high molecular sieve output and good high-temperature denitration activity, is suitable for industrial production, and has broad application prospects in the fields of environment, catalysis, etc. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is the XRD diagram of the molecular sieve type high temperature denitration catalyst A according to Example 1 of the present invention.
[0024] Figure 2 This is a scanning electron microscope image of the molecular sieve high-temperature denitration catalyst A of Example 1 of the present invention.
[0025] Figure 3 It is the denitration activity diagram of Examples 1-5 of the present invention and Comparative Examples 1-2. DETAILED DESCRIPTION
[0026] The present invention will be further described below in conjunction with embodiments, but the protection scope of the present invention is not limited thereto:
[0027] The following non-limiting examples are provided to enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way. The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.
[0028] Example 1
[0029] (1) Weigh 4.05 g of pseudo-boehmite (molecular weight: 81), 5.21 g of tetraethyl orthosilicate, 2.88 g of phosphoric acid (85%), 0.52 g of hydroxyethylidene diphosphoric acid, and 2.27 g of triethylamine, and add them to 14.7 g of tetraethylammonium hydroxide solution (25%) in sequence, mix them evenly, and obtain a hydrothermal precursor. Among them, the molar ratio of the aluminum source, silicon source, phosphorus source, template agent, and structure directing agent is 1Al: 0.5Si: 0.6P: 0.45triethylamine: 0.5tetraethylammonium hydroxide; the molar ratio of phosphoric acid to hydroxyethylidene diphosphoric acid is 1:0.1.
[0030] (2) placing the hydrothermal precursor obtained in step (1) into a hydrothermal reactor at a hydrothermal temperature of 180° C. for a reaction time of 3 days, washing and drying the hydrothermal product to obtain a layered SAPO-18 molecular sieve raw powder A;
[0031] (3) The layered SAPO-18 molecular sieve raw powder A obtained in step (2) is calcined at 600° C. for 3 h to obtain layered SAPO-18 molecular sieve A.
[0032] (4) 1 g of the layered SAPO-18 molecular sieve A obtained in step (3) was placed in 50 ml of a copper salt solution (0.2 M) and subjected to copper ion exchange at 70° C. for 5 h. After washing and drying, the mixture was calcined at 650° C. for 6 h to obtain a copper ion-type layered SAPO-18 molecular sieve catalyst A, i.e., a molecular sieve-type high-temperature denitration catalyst A. The XRD pattern of the denitration catalyst is shown in FIG. Figure 1 As shown in the scanning electron microscope image Figure 2 shown.
[0033] (5) The molecular sieve type high temperature denitrification catalyst A was tested for high temperature denitrification performance: NO in simulated flue gas x The initial concentration is 1000ppm, NH3 is 1000ppm, O2 concentration is 10%, and the air velocity is 50000h -1The particle size of the catalyst is 20-40 mesh. The denitration efficiency of the catalyst A is above 95% in the range of 430-680°C.
[0034] Example 2
[0035] (1) Weigh 3.9g aluminum hydroxide, 2.08g tetraethyl orthosilicate, 3.46g phosphoric acid (85%), 1.03g hydroxyethylidene diphosphoric acid, and 0.87g NN dimethylacetamide, and add them to 8.82g tetraethylammonium hydroxide solution (25%) in sequence, mix them evenly, and obtain a hydrothermal precursor. Among them, the molar ratio of aluminum source, silicon source, phosphorus source, template agent and structure directing agent is 1Al: 0.2Si: 0.8P: 0.3NN dimethylacetamide: 0.2tetraethylammonium hydroxide; the molar ratio of phosphoric acid to hydroxyethylidene diphosphoric acid is 1: 0.17.
[0036] (2) placing the hydrothermal precursor obtained in step (1) into a hydrothermal reactor at a hydrothermal temperature of 160° C. for a reaction time of 4 days, washing and drying the hydrothermal product to obtain a layered SAPO-18 molecular sieve raw powder B;
[0037] (3) The layered SAPO-18 molecular sieve raw powder B obtained in step (2) is calcined at 550° C. for 4 h to obtain layered SAPO-18 molecular sieve B.
[0038] (4) 1 g of the layered SAPO-18 molecular sieve B obtained in step (3) is placed in 50 ml of copper salt solution (0.4 M) and subjected to copper ion exchange at 60° C. for 4 h. After washing and drying, the mixture is calcined at 750° C. for 5 h to obtain a copper ion-type layered SAPO-18 molecular sieve catalyst B, i.e., a molecular sieve-type high-temperature denitration catalyst B.
[0039] (5) The molecular sieve type high temperature denitrification catalyst B was tested for high temperature denitrification performance: NO in simulated flue gas x The initial concentration is 1000ppm, NH3 is 1000ppm, O2 concentration is 10%, and the air velocity is 50000h -1 The particle size of the catalyst is 20-40 mesh. The denitration efficiency of the catalyst B is above 95% in the range of 450-690°C.
[0040] Example 3
[0041] (1) Weigh 4.05 g of pseudo-boehmite, 1.8 g of fumed silica, 3.46 g of phosphoric acid (85%), 1.55 g of hydroxyethylidene diphosphoric acid, and 1.31 g of morpholine, and add them to 10.92 g of tetramethylammonium hydroxide solution (25%) in sequence, mix them evenly, and obtain a hydrothermal precursor. The molar ratio of the aluminum source, silicon source, phosphorus source, template agent, and structure directing agent is 1Al: 0.6Si: 0.9P: 0.3morpholine: 0.6tetramethylammonium hydroxide; the molar ratio of phosphoric acid to hydroxyethylidene diphosphoric acid is 1: 0.25.
[0042] (2) placing the hydrothermal precursor obtained in step (1) into a hydrothermal reactor at a hydrothermal temperature of 170° C. for a reaction time of 3 days, washing and drying the hydrothermal product to obtain a layered SAPO-18 molecular sieve raw powder C;
[0043] (3) The layered SAPO-18 molecular sieve raw powder C obtained in step (2) was calcined at 600° C. for 2.5 hours to obtain a layered SAPO-18 molecular sieve C.
[0044] (4) 1 g of the layered SAPO-18 molecular sieve C obtained in step (3) is placed in 50 ml of copper salt solution (0.5 M) and subjected to copper ion exchange at 60° C. for 3 h. After washing and drying, the mixture is calcined at 700° C. for 6 h to obtain a copper ion-type layered SAPO-18 molecular sieve catalyst C, i.e., a molecular sieve-type high-temperature denitration catalyst C.
[0045] (5) The molecular sieve type high temperature denitrification catalyst C was tested for high temperature denitrification performance: NO in simulated flue gas x The initial concentration is 1000ppm, NH3 is 1000ppm, O2 concentration is 10%, and the air velocity is 50000h -1 The particle size of the catalyst is 20-40 mesh. The denitration efficiency of the catalyst C is above 95% in the range of 470-700°C.
[0046] Example 4
[0047] (1) Weigh 3.9g aluminum hydroxide, 2.7g fumed silica, 2.88g phosphoric acid (85%), 0.52g hydroxyethylidene diphosphoric acid, and 1.74g NN dimethylacetamide, add them to 12.74g tetramethylammonium hydroxide solution (25%) in sequence, mix them evenly, and obtain a hydrothermal precursor. Among them, the molar ratio of aluminum source, silicon source, phosphorus source, template agent and structure directing agent is 1Al: 0.9Si: 0.6P: 0.4NN dimethylacetamide: 0.7 tetramethylammonium hydroxide; the molar ratio of phosphoric acid to hydroxyethylidene diphosphoric acid is 1: 0.1.
[0048] (2) placing the hydrothermal precursor obtained in step (1) into a hydrothermal reactor at a hydrothermal temperature of 190° C. for a reaction time of 2 days, washing and drying the hydrothermal product to obtain a layered SAPO-18 molecular sieve raw powder D;
[0049] (3) The layered SAPO-18 molecular sieve raw powder D obtained in step (2) is calcined at 650° C. for 2 h to obtain layered SAPO-18 molecular sieve D.
[0050] (4) 1 g of the layered SAPO-18 molecular sieve D obtained in step (3) is placed in 50 ml of copper salt solution (0.2 M) and subjected to copper ion exchange at 50° C. for 5 h. After washing and drying, the mixture is calcined at 750° C. for 4 h to obtain a copper ion-type layered SAPO-18 molecular sieve catalyst D, i.e., a molecular sieve-type high-temperature denitrification catalyst D.
[0051] (5) The molecular sieve type high temperature denitrification catalyst D was tested for high temperature denitrification performance: NO in simulated flue gas x The initial concentration is 1000ppm, NH3 is 1000ppm, O2 concentration is 10%, and the air velocity is 50000h -1 The particle size of the catalyst is 20-40 mesh. The denitration efficiency of the catalyst D is above 95% in the range of 440-670°C.
[0052] Example 5
[0053] (1) Weigh 4.05 g of pseudo-boehmite, 4.16 g of tetraethyl orthosilicate, 2.88 g of phosphoric acid (85%), 1.03 g of hydroxyethylidene diphosphoric acid, and 0.76 g of triethylamine, and add them to 16.38 g of tetramethylammonium hydroxide solution (25%) in sequence, mix them evenly, and obtain a hydrothermal precursor. Among them, the molar ratio of the aluminum source, silicon source, phosphorus source, template agent, and structure directing agent is 1Al: 0.4Si: 0.7P: 0.15triethylamine: 0.9tetramethylammonium hydroxide; the molar ratio of phosphoric acid to hydroxyethylidene diphosphoric acid is 1:0.2.
[0054] (2) placing the hydrothermal precursor obtained in step (1) into a hydrothermal reactor at a hydrothermal temperature of 180° C. for a reaction time of 3 days, washing and drying the hydrothermal product to obtain a layered SAPO-18 molecular sieve raw powder E;
[0055] (3) The layered SAPO-18 molecular sieve raw powder E obtained in step (2) was calcined at 600° C. for 3 h to obtain layered SAPO-18 molecular sieve E.
[0056] (4) 1 g of the layered SAPO-18 molecular sieve E obtained in step (3) is placed in 50 ml of copper salt solution (0.3 M) and subjected to copper ion exchange at 70° C. for 4 h. After washing and drying, the mixture is calcined at 600° C. for 7 h to obtain a copper ion-type layered SAPO-18 molecular sieve catalyst E, i.e., a molecular sieve-type high-temperature denitrification catalyst E.
[0057] (5) The molecular sieve type high temperature denitrification catalyst E was tested for high temperature denitrification performance: NO in simulated flue gas x The initial concentration is 1000ppm, NH3 is 1000ppm, O2 concentration is 10%, and the air velocity is 50000h -1 The particle size of the catalyst is 20-40 mesh. The denitration efficiency of the catalyst E is above 95% in the range of 450-680°C.
[0058] Comparative Example 1
[0059] (1) Weigh 4.05 g of pseudo-boehmite, 5.21 g of tetraethyl orthosilicate, 3.46 g of phosphoric acid (85%), and 2.27 g of triethylamine, and add them to 14.7 g of tetraethylammonium hydroxide solution (25%) in sequence, mix them evenly, and obtain a hydrothermal precursor. The molar ratio of the aluminum source, silicon source, phosphorus source, template agent, and structure directing agent is 1Al: 0.5Si: 0.6P: 0.45triethylamine: 0.5tetraethylammonium hydroxide.
[0060] (2) placing the hydrothermal precursor obtained in step (1) into a hydrothermal reactor at a hydrothermal temperature of 180° C. for a reaction time of 3 days, washing and drying the hydrothermal product to obtain a layered SAPO-18 molecular sieve raw powder F;
[0061] (3) The layered SAPO-18 molecular sieve raw powder F obtained in step (2) is calcined at 600° C. for 3 hours to obtain layered SAPO-18 molecular sieve F.
[0062] (4) 1 g of the layered SAPO-18 molecular sieve F obtained in step (3) is placed in 50 ml of copper salt solution (0.2 M) and subjected to copper ion exchange at 70° C. for 5 h. After washing and drying, the mixture is calcined at 650° C. for 6 h to obtain a copper ion-type layered SAPO-18 molecular sieve catalyst F, i.e., a molecular sieve-type high-temperature denitrification catalyst F.
[0063] (5) The molecular sieve type high temperature denitrification catalyst F was tested for high temperature denitrification performance: NO in simulated flue gas x The initial concentration is 1000ppm, NH3 is 1000ppm, O2 concentration is 10%, and the air velocity is 50000h -1 The particle size of the catalyst is 20-40 mesh. The denitration efficiency of the catalyst F is 30-40% in the range of 480-690°C.
[0064] Comparative Example 2
[0065] (1) Weigh 3.9 g aluminum hydroxide, 2.08 g tetraethyl orthosilicate, 4.61 g phosphoric acid (85%), and 0.87 g NN dimethylacetamide, add them to 8.82 g tetraethylammonium hydroxide solution (25%) in sequence, mix them evenly, and obtain a hydrothermal precursor. The molar ratio of the aluminum source, silicon source, phosphorus source, template agent, and structure directing agent is 1Al: 0.2Si: 0.8P: 0.3NN dimethylacetamide: 0.2tetraethylammonium hydroxide.
[0066] (2) placing the hydrothermal precursor obtained in step (1) into a hydrothermal reactor at a hydrothermal temperature of 160° C. for a reaction time of 4 days, washing and drying the hydrothermal product to obtain a layered SAPO-18 molecular sieve raw powder G;
[0067] (3) The layered SAPO-18 molecular sieve raw powder G obtained in step (2) is calcined at 550° C. for 4 hours to obtain layered SAPO-18 molecular sieve G.
[0068] (4) 1 g of the layered SAPO-18 molecular sieve G obtained in step (3) was placed in 50 ml of copper salt solution (0.4 M) and subjected to copper ion exchange at 60° C. for 4 h. After washing and drying, the mixture was calcined at 750° C. for 5 h to obtain a copper ion-type layered SAPO-18 molecular sieve catalyst G.
[0069] (5) The molecular sieve type high temperature denitrification catalyst G was tested for high temperature denitrification performance: NO in simulated flue gas x The initial concentration is 1000ppm, NH3 is 1000ppm, O2 concentration is 10%, and the air velocity is 50000h -1 The particle size of the catalyst is 20-40 mesh. The denitration efficiency of the catalyst G is 30-45% in the range of 520-700°C.
Claims
1. A method for preparing a molecular sieve type high temperature denitration catalyst, characterized in that: The preparation method comprises the following steps: (1) adding an aluminum source, a silicon source, a phosphorus source and an organic template to a structure directing agent solution in sequence and mixing them uniformly to obtain a hydrothermal precursor; (2) placing the hydrothermal precursor obtained in step (1) into a hydrothermal reactor at a hydrothermal temperature of 150-200° C. for a reaction time of 2-5 days, washing and drying the hydrothermal product to obtain a layered SAPO-18 molecular sieve raw powder; (3) calcining the layered SAPO-18 molecular sieve powder obtained in step (2) at 500-700° C. for 2-5 hours to obtain a layered SAPO-18 molecular sieve. (4) The layered SAPO-18 molecular sieve obtained in step (3) is placed in a copper salt solution for ion exchange at 50-80° C. for 2-6 hours, washed and dried, and then calcined at 500-800° C. for 4-8 hours to obtain a copper ion-type layered SAPO-18 molecular sieve catalyst, i.e., a molecular sieve-type high-temperature denitration catalyst.
2. The method for preparing the molecular sieve type high temperature denitration catalyst according to claim 1, characterized in that: The aluminum source in step (1) is one of pseudo-boehmite and aluminum hydroxide, the silicon source is one of tetraethyl orthosilicate and fumed silica; the phosphorus source is phosphoric acid and hydroxyethylidene diphosphoric acid; The organic template is one of triethylamine, morpholine and NN dimethylacetamide; the structure directing agent is one of tetramethylammonium hydroxide and tetraethylammonium hydroxide, and the concentration of the structure directing agent solution is 20-30%.
3. The method for preparing the molecular sieve type high temperature denitration catalyst according to claim 1, characterized in that: The molar ratio of phosphoric acid to hydroxyethylidene diphosphoric acid is 1:0.1-1.
4. The method for preparing the molecular sieve type high temperature denitration catalyst according to claim 3, characterized in that: The molar ratio of phosphoric acid to hydroxyethylidene diphosphoric acid is 1:0.1-0.
3.
5. The method for preparing the molecular sieve type high temperature denitration catalyst according to claim 1, characterized in that: The molar ratio of the aluminum source, silicon source, phosphorus source, template and structure directing agent in step (1) is 1:(0.1-2):(0.1-1):(0.1-1):(0.1-1).
6. The method for preparing the molecular sieve type high temperature denitration catalyst according to claim 5, characterized in that: The molar ratio of the aluminum source, silicon source, phosphorus source, template agent and structure directing agent is 1: (0.1-1): (0.2-1): (0.1-0.5): (0.1-1).
7. The method for preparing a molecular sieve type high temperature denitration catalyst according to claim 1, characterized in that: The mass ratio of the layered SAPO-18 molecular sieve to the copper salt solution is 1:40-60, and the concentration of the copper salt solution is 0.1-1M.
8. A molecular sieve type high temperature denitration catalyst, characterized in that: The catalyst is prepared by the method according to any one of claims 1 to 7.
9. Application of the copper ion type layered SAPO-18 molecular sieve catalyst prepared by the method of claim 1 in high temperature denitration of flue gas.
10. The use according to claim 6, characterized in that: NO x The initial concentration is 100-1500ppm, NH3 is 100-1500ppm, O2 concentration is 5-15%, and the air velocity is 40000-60000h -1 , the particle size of the catalyst is 20-40 mesh, and the reaction temperature ranges from 300-750°C.