Catalyst, process for its preparation and use

Abstract

This invention relates to the field of catalyst technology, specifically to catalysts, their preparation methods, and applications. The catalyst comprises active components Ta, W, and Al, and an auxiliary agent M, wherein M is selected from at least one alkali metal element and Ag. The molar ratio of M to Ta, W, and Al, based on metal elements, is 1:(1-13):(4-34):(100-573), and the content of Ru accounts for less than 0.1 mol% of the total content of all metal elements. The catalyst provided by this invention exhibits excellent catalytic performance in the synthesis of 2-methoxypropylene.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to catalysts, their preparation methods, and applications. Background Technology

[0002] 2-Methoxypropylene is the simplest alkenyl ether with a wide range of applications. It is a key intermediate in the synthesis of various drugs, dyes, and materials, including clarithromycin, pseudoionone, vitamins, and carotene. Due to its huge demand, researching and developing simple, efficient, and large-scale industrial-scale synthesis methods for 2-methoxypropylene is of paramount importance.

[0003] The gas-phase cracking method for synthesizing 2-methoxypropene is a widely used approach. This method utilizes a specific cracking catalyst. At a certain temperature, the feedstock 2,2-dimethoxypropane passes through a catalyst bed and directly loses one molecule of methanol to generate the target product, 2-methoxypropene. The reaction equation is as follows:

[0004]

[0005] Compared to other methods such as direct synthesis and liquid-phase pyrolysis, gas-phase pyrolysis offers advantages such as simple post-processing, easy product separation, and no need for organic solvents, thus attracting considerable attention. Research on this method focuses primarily on catalyst preparation processes, with catalyst selectivity and the yield of 2-methoxypropene being the most important evaluation targets. CN1218791A discloses a method for preparing enol ethers via a gas-phase reaction of acetals / ketals on a highly porous oxide heterogeneous catalyst. The catalyst is selected from magnesium oxide, alumina, silica, zinc oxide, titanium oxide, or mixtures thereof, and the reaction temperature is 220-300℃. However, even with improved conversion rates of 2,2-dimethoxypropane through byproduct separation and raw material recycling, the conversion rate remains below 80%. CN1660742A discloses a process for synthesizing 2-alkoxypropene in a 1-m long tower reactor. The catalyst used is acidic ceramic, cationic resin, heteropolyacid, or acidic molecular sieve. The optimal yield of 2-methoxypropene, reaching 95.6%, is achieved when using acidic ceramic. Although existing literature and patents have reported on the application of various related catalysts in the gas-phase cracking synthesis of 2-methoxypropylene, the development of catalytic systems with higher activity and selectivity is still of great significance for reducing production costs. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems in the existing technology where the conversion rate of 2,2-dimethoxypropane and the selectivity and yield of 2-methoxypropylene need to be further improved, and to provide a catalyst, its preparation method and application.

[0007] To achieve the above objectives, the first aspect of the present invention provides a catalyst, wherein the catalyst comprises active components Ta, W, Al and promoter M, wherein M is selected from at least one of alkali metal elements and Ag, and the molar ratio of M to Ta, W and Al, based on metal elements, is 1:(1-13):(4-34):(100-573), and the content of Ru accounts for less than 0.1 mol% of the total content of all metal elements.

[0008] A second aspect of the present invention provides a method for preparing a catalyst, the method comprising the following steps: mixing an M source, a tantalum source, a tungsten source and an aluminum source to form a gel, drying and calcining the obtained gel, wherein M is selected from at least one of an alkali metal element and Ag; the amounts of the M source, tantalum source, tungsten source and aluminum source are such that, in the catalyst, the molar ratio of M to Ta, W and Al, based on metal elements, is 1:(1-13):(4-34):(100-573).

[0009] A third aspect of the present invention provides a catalyst prepared by the preparation method described above.

[0010] The fourth aspect of the present invention provides the application of the catalyst described in the first and third aspects of the present invention in catalytic gas-phase cracking reactions, preferably in the preparation of 2-alkoxypropane from 2-alkoxypropane, and more preferably in the preparation of 2-methoxypropane from 2,2-dimethoxypropane.

[0011] The fifth aspect of the present invention provides a method for synthesizing 2-methoxypropene, wherein the method comprises: subjecting 2,2-dimethoxypropane to a gas-phase cracking reaction in the presence of a catalyst, said catalyst comprising the catalysts described in the first and third aspects of the present invention.

[0012] Through the above technical solution, the catalyst provided by the present invention exhibits good catalytic performance in the synthesis of 2-methoxypropylene. In the preferred embodiment, the conversion rate of 2,2-dimethoxypropane is above 85%, and the selectivity of 2-methoxypropylene is above 90%. Detailed Implementation

[0013] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0014] The first aspect of the present invention provides a catalyst, wherein the catalyst comprises active components Ta, W, Al and promoter M, wherein M is selected from at least one of alkali metal elements and Ag, and the molar ratio of M to Ta, W and Al, based on metal elements, is 1:(1-13):(4-34):(100-573), and the content of Ru accounts for less than 0.1 mol% of the total content of all metal elements.

[0015] In this invention, the inventors discovered through extensive experimental research that by selecting oxides of tantalum, tungsten, and aluminum as active components and optimizing the addition ratios of each active component and auxiliary agent, the catalytic activity of the catalyst can be effectively improved. In this invention, excessively high content of active components leads to low selectivity, while excessively low content leads to low conversion rate; excessively high content of auxiliary agents will cover the active components, causing a decrease in catalytic performance, while excessively low content will have no significant promoting effect on catalytic performance.

[0016] In this invention, the aforementioned catalyst composition can achieve the purpose of this invention. In order to further improve the activity of the catalyst and further improve the selectivity and yield of 2-methoxypropylene in the product, preferably, the molar ratio of M to Ta, W and Al, based on metal elements, is 1:(3-10):(12-26):(162-400); more preferably, the molar ratio of M to Ta, W and Al, based on metal elements, is 1:(3-10):(12-20):(180-250).

[0017] In this invention, preferably, the catalyst may be Ru-free.

[0018] In this invention, to improve the activity of the catalyst, preferably, the specific surface area of ​​the catalyst structure can be 20-250 m². 2 / g, for example, can be 20m 2 / g、30m 2 / g、40m 2 / g, 50m 2 / g、60m 2 / g、70m 2 / g、80m 2 / g、90m 2 / g, 100m 2 / g、110m 2 / g、120m 2 / g、130m 2 / g, 140m 2 / g, 150m 2 / g、160m 2 / g、170m 2 / g、180m 2 / g、190m 2 / g、200m2 / g、210m 2 / g、220m 2 / g、230m 2 / g、240m 2 / g、250m 2 / g and any value within the range of any two of the above numerical values, more preferably, the catalyst structure has a specific surface area of ​​100-200 m². 2 / g, further preferably 120-140m 2 / g.

[0019] In this invention, preferably, the alkali metal element is selected from at least one of Li, Na, K, Rb, and Cs. In this invention, the addition of the auxiliary agent is beneficial for increasing the alkaline sites in the catalyst.

[0020] In some preferred embodiments of the present invention, when M is at least one of K, Na, and Ag, the catalyst has better activity; more preferably, when M is K, a combination of Ag and K, a combination of Ag and Na, or a combination of Ag and K and Na; even more preferably, when M is a combination of Ag and K, a combination of Ag and Na, or a combination of Ag and K and Na, the molar amounts of Ag, K, and Na can be the same.

[0021] In this invention, preferably, M exists in the form of carbonate and / or oxide.

[0022] In this invention, preferably, when M is selected from Li and / or Ag, M can exist in the form of an oxide.

[0023] In this invention, the active component exists in the form of an oxide.

[0024] In this invention, Ta is preferably present in the form of Ta2O5.

[0025] In this invention, preferably, W exists in the form of WO3.

[0026] In this invention, Al is preferably present in the form of Al2O3.

[0027] According to a preferred embodiment of the present invention, the catalyst comprises active components Ta, W, Al and promoter M, wherein M is at least one of K, Na and Ag; the molar ratio of M to Ta, W and Al, based on metal elements, is 1:(3-10):(12-20):(180-250), and it does not contain Ru.

[0028] According to a particularly preferred embodiment of the present invention, the catalyst comprises active components Ta, W, Al and promoter M, wherein M is K, or M is a combination of Ag and K, a combination of Ag and Na, or a combination of Ag, K and Na; the molar ratio of M to Ta, W and Al, based on metal elements, is 1:(3-10):(12-20):(180-250), and it does not contain Ru.

[0029] A second aspect of the present invention provides a method for preparing a catalyst, the method comprising the following steps: mixing an M source, a tantalum source, a tungsten source and an aluminum source to form a gel, drying and calcining the obtained gel, wherein M is selected from at least one of an alkali metal element and Ag; the amounts of the M source, tantalum source, tungsten source and aluminum source are such that, in the catalyst, the molar ratio of M to Ta, W and Al, based on metal elements, is 1:(1-13):(4-34):(100-573).

[0030] In this invention, the above preparation methods can all achieve the purpose of preparing catalysts. In order to further improve the activity of the catalyst, and further improve the conversion rate of 2,2-dimethoxypropane and the selectivity of 2-methoxypropylene, in some specific embodiments of this invention, the amounts of M source, tantalum source, tungsten source and aluminum source are such that the molar ratio of M to Ta, W and Al in the catalyst, based on metal elements, is 1:(3-10):(12-26):(162-400); more preferably, the molar ratio of M to Ta, W and Al, based on metal elements, is 1:(3-10):(12-20):(180-250).

[0031] In this invention, preferably, the alkali metal element is selected from at least one of Li, Na, K, Rb and Cs.

[0032] In some preferred embodiments of the present invention, when M is at least one of K, Na, and Ag, the catalyst has better activity; more preferably, M is a combination of K, Ag, and K, a combination of Ag and Na, or a combination of Ag, K, and Na; even more preferably, when M is a combination of Ag and K, a combination of Ag and Na, or a combination of Ag, K, and Na, the molar amounts of Ag, K, and Na can be the same.

[0033] According to a preferred embodiment of the present invention, the mixture of M source, tantalum source, tungsten source and aluminum source forms a gel, and the resulting gel is dried and calcined, wherein M is at least one of K, Na and Ag; the amounts of M source, tantalum source, tungsten source and aluminum source are such that, in the catalyst, the molar ratio of M to Ta, W and Al, based on metal elements, is 1:(3-10):(12-20):(180-250).

[0034] According to a particularly preferred embodiment of the present invention, the mixture of M source, tantalum source, tungsten source and aluminum source forms a gel, and the resulting gel is dried and calcined, wherein M is selected from K, or M is a combination of Ag and K, a combination of Ag and Na, or a combination of Ag and K and Na; the amounts of M source, tantalum source, tungsten source and aluminum source are such that, in the catalyst, the molar ratio of M to Ta, W and Al, based on metal elements, is 1:(3-10):(12-20):(180-250).

[0035] In this invention, the M source can be a water-soluble M salt commonly used in the art, selected from water-soluble salts of M, and commercially available. For example, the M source can be selected from at least one of halides, acetates, and nitrates of M.

[0036] In this invention, the selection of the tantalum source is not particularly limited and can be a conventional tantalum salt in the art, selected from water-soluble salts of tantalum, and commercially available. For example, the tantalum source can be selected from at least one of tantalum ethoxide, tantalum isopropoxide, and tantalum pentachloride. To further improve the catalyst activity, in a preferred embodiment of this invention, the tantalum source is tantalum pentachloride.

[0037] In this invention, there is no particular limitation on the selection of the tungsten source. It can be a water-soluble tungsten salt commonly used in the art, selected from water-soluble salts of tungsten, and commercially available. For example, the tungsten source can be selected from at least one of ammonium tungsten oxide, ammonium paratungstate, and ammonium metatungstate.

[0038] In this invention, there is no particular limitation on the selection of the aluminum source. It can be a water-soluble aluminum source commonly used in the art, selected from water-soluble salts of aluminum, and commercially available. For example, the aluminum source is at least one of aluminum trichloride, aluminum sulfate, and aluminum nitrate.

[0039] In this invention, preferably, the mixing is carried out in the presence of a pore-forming agent. The pore-forming agent should be compatible with the M source, tantalum source, tungsten source, and aluminum source, and be capable of mild decomposition.

[0040] In this invention, preferably, the pore-forming agent comprises C2-C15 organic acids and / or nonionic hydrophilic polymers. To further improve the selectivity and activity of the prepared catalyst, the pore-forming agent is more preferably a C2-C15 organic acid and a nonionic hydrophilic polymer, and even more preferably a C4-C9 organic acid and a nonionic hydrophilic polymer.

[0041] In this invention, preferably, the organic acid is at least one selected from succinic acid, gallic acid, and citric acid.

[0042] In this invention, preferably, the nonionic hydrophilic polymer is polyethylene glycol. The polyethylene glycol can be any commercially available polyethylene glycol commonly used in the art; preferably, the average molecular weight of the polyethylene glycol can be 200-10000, for example, 200, 500, 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, or any value within any two of the above ranges.

[0043] In this invention, to improve the activity of the prepared catalyst, preferably, the molar amount of the organic acid is 1-2 times the total molar amount of all metal cations in the metal salt solution, for example, it can be 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2 times, or any value within any two of the above ranges. More preferably, the molar amount of the organic acid is 1-1.4 times the total molar amount of all metal cations in the metal salt solution; within this range, the activity and selectivity of the prepared catalyst are further improved.

[0044] In this invention, preferably, the mass of the nonionic hydrophilic polymer is 0.3-1 times the mass of the organic acid, for example, it can be 0.3 times, 0.4 times, 0.5 times, 0.6 times, 0.7 times, 0.8 times, 0.9 times, 1 times, or any value within any two of the above-mentioned numerical ranges. To further improve the activity and selectivity of the prepared catalyst, it is more preferably 0.4-0.6 times.

[0045] In this invention, preferably, the method for preparing the gel-like substance includes: dissolving the M source, tantalum source, tungsten source and aluminum source in an alcohol-based organic solvent to form a metal salt solution, mixing the metal salt solution with a pore-forming agent, and then heating until a viscous gel-like substance is formed.

[0046] In this invention, there are no particular limitations on the implementation of the mixing method. For example, the metal salt solution can be added to the pore-forming agent, or the pore-forming agent can be added to the metal salt solution. Preferably, the pore-forming agent is added to the metal salt solution.

[0047] In this invention, there is no particular limitation on the total molar concentration of all metal cations in the metal salt solution, as long as the concentration meets the requirements for preparing the catalyst. However, in order to prepare a catalyst with high activity, preferably, the total molar concentration of all metal cations in the metal salt solution is 0.5-3 mol / L, for example, 0.5 mol / L, 0.8 mol / L, 1 mol / L, 1.4 mol / L, 1.8 mol / L, 2.2 mol / L, 2.6 mol / L, 3 mol / L, and any value within any two of the above ranges, more preferably 1.4-1.8 mol / L.

[0048] In this invention, the alcohol-based organic solvent is sufficient to dissolve the M source, tantalum source, tungsten source, and aluminum source. In some specific embodiments of this invention, the alcohol-based organic solvent is preferably ethanol, and more preferably anhydrous ethanol.

[0049] In this invention, the heating temperature is not particularly limited, as long as the metal salt solution and the pore-forming agent can be mixed to form a viscous gel. For example, the heating temperature can be 50-120°C, preferably 60-90°C.

[0050] In this invention, the drying conditions are not particularly limited, as long as the solvent adhering to the gel can be removed. For example, the drying conditions typically include: a drying temperature of 80-150°C, preferably 100-130°C; and a drying time of 3-20 hours, preferably 3-5 hours.

[0051] In this invention, the calcination temperature can be 400-800℃, for example, 400℃, 500℃, 600℃, 700℃, 800℃, and any value within the range of any two of the above values. Preferably, the calcination temperature is 500-700℃.

[0052] In this invention, the calcination time can be 1-8 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, or any two of the above values, preferably 3-5 hours.

[0053] In this invention, when the calcination temperature and calcination time are within the above-mentioned range, it is beneficial to remove pore-forming agents and water-soluble salts, and can reduce the loss of catalyst specific surface area.

[0054] A third aspect of the present invention provides a catalyst prepared by the preparation method described in the second aspect of the present invention.

[0055] The fourth aspect of the present invention provides the application of the catalyst described in the first and third aspects of the present invention in catalytic gas-phase cracking reactions, preferably in the preparation of 2-alkoxypropane from 2-alkoxypropane, and more preferably in the preparation of 2-methoxypropane from 2,2-dimethoxypropane.

[0056] The fifth aspect of the present invention provides a method for synthesizing 2-methoxypropene, wherein the method comprises: subjecting 2,2-dimethoxypropane to a gas-phase cracking reaction in the presence of a catalyst, said catalyst comprising the catalysts described in the first and third aspects of the present invention.

[0057] In this invention, preferably, the gas-phase pyrolysis reaction conditions include:

[0058] The reaction temperature can be above 120℃. Considering the needs of actual production, production costs, and catalyst activity, the reaction temperature is preferably 120-360℃, for example, it can be 120℃, 150℃, 180℃, 200℃, 220℃, 250℃, 270℃, 300℃, 330℃, 360℃, or any value within any two of the above ranges. More preferably, under the premise of high catalyst activity, and to further reduce production costs, the reaction temperature is 150-250℃.

[0059] The space velocity (HV) of 2,2-dimethoxypropane is greater than 0 mL / min / g. Considering the needs of actual production, in some embodiments of the present invention, the HV can be 0.001-0.02 mL / min / g, for example, 0.001 mL / min / g, 0.003 mL / min / g, 0.005 mL / min / g, 0.008 mL / min / g, 0.01 mL / min / g, 0.013 mL / min / g, 0.015 mL / min / g, 0.018 mL / min / g, or 0.02 mL / min / g. In the present invention, the 2,2-dimethoxypropane in the gas-phase cracking reaction exists in gaseous form. To achieve the vaporization of liquid 2,2-dimethoxypropane, conventional techniques in the art can be used, such as heating in a vaporization vessel. The technique used should be sufficient to achieve the purpose of vaporizing 2,2-dimethoxypropane.

[0060] In this invention, the reactor for the catalytic reaction is not particularly limited and can be any reactor commonly used in the art, such as a fixed-bed reactor.

[0061] The present invention will be described in detail below through embodiments, but it should be understood that the scope of protection of the present invention is not limited to the embodiments.

[0062] In the following examples and comparative examples, the raw materials used were commercially available products.

[0063] Example 1

[0064] Weigh 0.51g potassium nitrate (auxiliary agent), 10.75g tantalum pentachloride, 17.36g ammonium metatungstate, and 375.1g aluminum nitrate nonahydrate, and add them to 700mL anhydrous ethanol to form a clear and transparent solution. Weigh 254.77g citric acid and 127.38g polyethylene glycol (average molecular weight 2000), and add them to the above mixed solution. Stir until completely dissolved. Heat and stir the mixed solution at 80℃ for 6 hours until a viscous gel is formed, and then dry it at 110℃ for 4 hours. Calcine the dried catalyst precursor at 600℃ for 4 hours to obtain catalyst S1.

[0065] The catalyst S1 obtained has a specific surface area of ​​133 m². 2 / g.

[0066] Example 2

[0067] The method is the same as in Example 1, except that the auxiliary agent in the raw materials is 0.42g of sodium nitrate, and the catalyst obtained is denoted as S2.

[0068] Example 3

[0069] The method is the same as in Example 1, except that the auxiliary agent in the raw materials is 0.85g of silver nitrate, and the catalyst obtained is designated as S3.

[0070] Example 4

[0071] The method of Example 1 is followed, except that the additives in the raw materials are 0.43g silver nitrate and 0.25g potassium nitrate, and the resulting catalyst is designated as S4.

[0072] Example 5

[0073] The method was followed in Example 1, except that the auxiliary agent in the raw materials was 0.3g potassium nitrate, the tantalum source was 3.22g tantalum pentachloride, the tungsten source was 4.22g ammonium metatungstate, and the aluminum source was 375.1g aluminum nitrate nonahydrate. The resulting catalyst was designated S5.

[0074] Example 6

[0075] The method was followed in Example 1, except that the additives in the raw materials were 0.21g potassium nitrate, 7.88g tantalum pentachloride, 2.73g ammonium metatungstate, and 375.1g aluminum nitrate nonahydrate. The resulting catalyst was designated S6.

[0076] Example 7

[0077] The raw material composition was the same as in Example 1, except that the heating temperature was 110°C and the heating time was 2 hours, the drying temperature was 140°C and the drying time was 8 hours, and the calcination temperature was 700°C and the calcination time was 4 hours. The resulting catalyst is designated as S7.

[0078] Comparative Example 1

[0079] The method of Example 1 was followed, except that the auxiliary agent in the raw materials was 1.51 g of potassium nitrate, and the resulting catalyst was designated as D1. The results are shown in Table 1.

[0080] Comparative Example 2

[0081] The method is the same as in Example 1, except that the auxiliary agent in the raw materials is 2.55g of silver nitrate, and the catalyst obtained is denoted as D2.

[0082] Comparative Example 3

[0083] The method of Example 1 was followed, except that the amount of tantalum pentachloride added was 25.07 g and the amount of ammonium metatungstate added was 7.44 g. The resulting catalyst was designated as D3.

[0084] Comparative Example 4

[0085] The catalyst prepared according to the method of Example 1, except that no additives were added, is designated as D4.

[0086] Comparative Example 5

[0087] The catalyst prepared according to the method of Example 1, except that tantalum pentachloride was not added, is designated as D5.

[0088] Comparative Example 6

[0089] The catalyst prepared according to the method of Example 1, except that ammonium metatungstate was not added, is designated as D6.

[0090] Comparative Example 7

[0091] The method of Example 1 was followed, except that the amount of potassium nitrate added was 5.1g, the amount of tantalum pentachloride added was 107.5g, the amount of ammonium metatungstate added was 173.6g, and aluminum nitrate nonahydrate was not added. The resulting catalyst was designated as D7.

[0092] Comparative Example 8

[0093] The method of Example 1 was followed, except that only 375.1g of aluminum nitrate nonahydrate was added, and no additives, ammonium metatungstate and tantalum pentachloride were added. The resulting catalyst was designated as D8.

[0094] Comparative Example 9

[0095] The purchased sulfonic acid-modified acidic ceramics were used, with an acid content of 0.5 mmol / g.

[0096] Comparative Example 10

[0097] The raw material composition and preparation method were the same as in Example 1, except that the calcination temperature was 900°C. The resulting catalyst was designated D10.

[0098] Comparative Example 11

[0099] The method of Example 1 was followed, except that potassium nitrate was not added, and 1.04 g of ruthenium trichloride was added instead. The resulting catalyst was designated D11.

[0100] Test case

[0101] The catalysts obtained in the above examples and comparative examples were compressed into tablets, crushed, and sieved to obtain 60-80 mesh particles for use in the gas-phase cracking of 2,2-dimethoxypropane to synthesize 2-methoxypropylene.

[0102] The specific reaction evaluation steps and conditions included: placing 30g of catalyst in a fixed-bed reactor; introducing 2,2-dimethoxypropane gas at a flow rate of 0.27mL / min; and carrying out the reaction at 200℃. The reaction liquid condensed after flowing through the fixed bed was then subjected to chromatographic analysis to obtain the conversion, selectivity, and yield of 2-methoxypropene. The results are shown in Table 1.

[0103] Gas chromatograph, manufactured by Shimadzu Corporation, model GC-2014C; external standard method.

[0104] The catalytic products were analyzed by gas chromatography. XPS analysis revealed that the composition of each metal element in the catalyst was close to the amount of feed, and Ru was not present. Atomic spectroscopy analysis showed that Ta, W, Al, Na, K and Ag existed in the forms of Ta2O5, WO3, Al2O3, Na2CO3, K2CO3 and Ag2O, respectively.

[0105] 2,2-Dimethoxypropane conversion rate = (molar amount of 2,2-dimethoxypropane consumed in the reaction / molar amount of 2,2-dimethoxypropane added to the reaction) × 100%.

[0106] 2-Methoxypropene selectivity = (molar amount of 2-methoxypropene produced in the reaction / theoretically produced molar amount of 2-methoxypropene) × 100%.

[0107] Table 1

[0108]

[0109]

[0110] As can be seen from the results in Table 1, the catalysts prepared in Examples 1-7, using specific active components, additives, and specific ratios and preparation methods, exhibit both high conversion rates and excellent selectivity.

[0111] Compared to using acidic ceramics as catalysts, the catalysts prepared in Examples 1-7 of this invention can further improve the conversion rate of 2,2-dimethoxypropane.

[0112] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalyst for the preparation of 2-alkoxypropane from 2-alkoxypropane, characterized in that, The catalyst comprises active components Ta, W, Al and promoter M, wherein M is selected from K and / or Ag, and the molar ratio of M to Ta, W and Al is 1:(3-10):(12-26):(162-400) based on the metal element. The catalyst does not contain Ru.

2. The catalyst according to claim 1, wherein, The specific surface area of ​​the catalyst is 20-250 m². 2 / g.

3. The catalyst according to claim 1, wherein, M exists in the form of carbonates and / or oxides; And / or, Ta exists in the form of Ta2O5; And / or, W exists in the form of WO3; And / or, Al exists in the form of Al2O3.

4. A method for preparing a catalyst for the preparation of 2-alkoxypropane from 2-alkoxypropane, characterized in that, Includes the following steps: M source, tantalum source, tungsten source and aluminum source are mixed to form a gel, and the resulting gel is dried and calcined, wherein M is selected from K and / or Ag; the amount of M source, tantalum source, tungsten source and aluminum source is such that the molar ratio of M to Ta, W and Al in the catalyst, based on metal elements, is 1:(3-10):(12-26):(162-400).

5. The method according to claim 4, wherein, The source M is a water-soluble salt of M.

6. The method according to claim 5, wherein, The M source is at least one of the halides, acetates, and nitrates of M.

7. The method according to claim 4, wherein, The tantalum source is at least one of tantalum ethoxide, tantalum isopropoxide, and tantalum pentachloride.

8. The method according to claim 7, wherein, The tantalum source is tantalum pentachloride.

9. The method according to claim 4, wherein, The tungsten source is a water-soluble salt of tungsten.

10. The method according to claim 9, wherein, The tungsten source is at least one of ammonium tungsten oxide, ammonium paratungstate, and ammonium metatungstate.

11. The method according to claim 4, wherein, The aluminum source is a water-soluble salt of aluminum.

12. The method according to claim 11, wherein, The aluminum source is at least one of aluminum trichloride, aluminum sulfate, and aluminum nitrate.

13. The method according to claim 4, wherein, The drying temperature is 80-150℃.

14. The method according to claim 13, wherein, The drying temperature is 100-130℃.

15. The method according to claim 4, wherein, The drying time is 3-20 hours.

16. The method according to claim 15, wherein, The drying time is 3-5 hours.

17. The method according to claim 4, wherein, The calcination temperature is 400-800℃.

18. The method according to claim 17, wherein, The calcination temperature is 500-700℃.

19. The method according to claim 4, wherein, The calcination time is 1-8 hours.

20. The method according to claim 19, wherein, The calcination time is 3-5 hours.

21. The method according to claim 4, wherein, The mixing is carried out in the presence of a pore-forming agent.

22. The method according to claim 21, wherein, The pore-forming agent comprises C2-C15 organic acids and / or nonionic hydrophilic polymers.

23. The method according to claim 22, wherein, The pore-forming agent is a C2-C15 organic acid and a nonionic hydrophilic polymer.

24. The method according to claim 23, wherein, The pore-forming agent is a C4-C9 organic acid and a nonionic hydrophilic polymer.

25. The method according to claim 24, wherein, The organic acid is at least one of succinic acid, gallic acid, and citric acid.

26. The method according to claim 24, wherein, The nonionic hydrophilic polymer is polyethylene glycol.

27. The method according to claim 24, wherein, The molar amount of the organic acid is 1-2 times the total molar amount of all metal cations in the metal salt solution.

28. The method according to claim 27, wherein, The molar amount of the organic acid is 1 to 1.4 times the total molar amount of all metal cations in the metal salt solution.

29. The method according to claim 24, wherein, The mass of the nonionic hydrophilic polymer is 0.3-1 times the mass of the organic acid.

30. The method according to claim 29, wherein, The mass of the nonionic hydrophilic polymer is 0.4-0.6 times the mass of the organic acid.

31. The method according to any one of claims 4-30, wherein, The method for preparing the gel-like substance includes: dissolving the M source, tantalum source, tungsten source and aluminum source in an alcohol-based organic solvent to form a metal salt solution, mixing the metal salt solution with a pore-forming agent, and then heating until a viscous gel-like substance is formed.

32. The method according to claim 31, wherein, The total molar concentration of all metal cations in the metal salt solution is 0.5-3 mol / L.

33. The method according to claim 32, wherein, The total molar concentration of all metal cations in the metal salt solution is 1.4-1.8 mol / L.

34. The method according to claim 31, wherein, The alcohol-based organic solvent is ethanol.

35. The method according to claim 34, wherein, The alcohol-based organic solvent is anhydrous ethanol.

36. The method according to claim 31, wherein, The heating temperature is 50-120℃.

37. The method of claim 36, wherein, The heating temperature is 60-90℃.

38. A catalyst prepared by the method of any one of claims 4-37.

39. The use of a catalyst according to any one of claims 1-3 and 38 in the preparation of 2-alkoxypropane from 2-alkoxypropane.

40. The application according to claim 39, wherein, The application of the catalyst in the preparation of 2-methoxypropylene from 2,2-dimethoxypropane.

41. A method for synthesizing 2-methoxypropylene, characterized in that, The method includes: subjecting 2,2-dimethoxypropane to a gas-phase cracking reaction in the presence of a catalyst, said catalyst comprising any one of claims 1-3 and 38.

42. The method according to claim 41, wherein, The gas-phase pyrolysis reaction conditions include a reaction temperature of 120-360℃.

43. The method according to claim 42, wherein, The gas-phase pyrolysis reaction conditions include a reaction temperature of 150-250℃.

44. The method according to claim 42, wherein, The gas-phase pyrolysis reaction conditions include a space velocity of 0.001-0.02 mL / min / g for 2,2-dimethoxypropane.

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