Preparation method of supported molybdenum-based catalyst and application thereof

Abstract

The application discloses a preparation method of a supported molybdenum-based catalyst, which comprises the following steps: dissolving ammonium heptamolybdate tetrahydrate and another metal salt in an isopropyl alcohol solution, and then preparing a series of molybdenum-based catalysts with different metal molar ratios by using different carriers through an equal-volume impregnation method; and a method for preparing furan chemicals by using the supported molybdenum-based catalyst, which comprises the following steps: taking glucose as a substrate, taking water and acetylacetone as solvents, mixing the substrate, the solvents and the molybdenum-based catalyst in a certain proportion, and then heating and stirring at 70-150 DEG C for 1-180 min to perform C-C bond breaking and nucleophilic addition cascade reaction, so as to obtain furan chemicals. The application can prepare multiple types of high-value furan compounds from biomass-based sugars, has the characteristics of green and mild reaction conditions, simple catalyst preparation, high conversion efficiency and high furan chemical yield, and presents a good industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of chemical technology, specifically to a method for preparing a supported molybdenum-based catalyst and its application. Background Technology

[0002] Furans and their derivatives are a class of oxygen-containing five-membered heterocyclic organic small molecules, a common structure in bioactive compounds, thus serving as important drug precursors. They are widely used in the synthesis of polymer materials, such as furan resins and as curing agents for epoxy resins, making them excellent polymer monomers. They can also be used to synthesize photochromic molecules and biofuels, and as food additives. In response to the growing demands of modern society, developing efficient catalytic conversion pathways to prepare novel furan chemicals from renewable sugars is of great significance for promoting the sustainable development of biomass refining and upgrading processes, and helps alleviate dependence on fossil fuels.

[0003] The preparation of furan compounds from carbohydrates mainly focuses on the dehydration to produce 5-hydroxymethylfurfural (HMF) and furfural. Numerous studies use HMF and furfural as starting substrates to further prepare high-value furan derivatives such as 2,5-dicarboxyfuran, 2,5-furandicarboxylic acid (DFF), 2,5-furandiethanol, furoic acid, and furfuryl alcohol via oxidation or hydrogenation reactions. Relatively few studies have focused on the synthesis of other types of furan compounds. Using molybdic acid as a catalyst, glucose was cleaved via the C-C bond under mild conditions to yield highly reactive C2-ethanolaldehyde and C4-erythrose intermediates. Using acetylacetone as a trapping agent for these intermediates, two novel furan compounds were obtained: C2-derived 2-methyl-3-acetylfuran and C4-derived 2-methyl-3-acetyl-5-(1,2-hydroxy)furan. However, due to the high activation energy of the C-C bond cleavage reaction, the total carbon yield of this reaction is only 50%, and the catalyst cannot be recycled. In summary, current methods for directly converting inexpensive sugars to prepare novel furan compounds suffer from problems such as low carbon atom utilization, low catalyst efficiency, and inability to recycle the catalysts.

[0004] Therefore, in order to solve the above problems, this paper proposes a method for preparing a supported molybdenum-based catalyst and its application. Summary of the Invention

[0005] The purpose of this invention is to provide a supported molybdenum-based catalyst that is simple to prepare, has high catalytic efficiency, and can realize complex cascade reactions from glucose to high-value furan chemicals under mild conditions.

[0006] To achieve the above-mentioned technical effects, the present invention is implemented through the following technical solution: a method for preparing a supported molybdenum-based catalyst, characterized by comprising the following steps:

[0007] S1. Preparation of bimetallic aqueous solution: Weigh ammonium heptamolybdate tetrahydrate and another metal salt in a molar ratio of 1:0.1-1, and then dissolve the ammonium heptamolybdate tetrahydrate and the metal salt in 8-12% isopropanol solution to prepare a bimetallic aqueous solution.

[0008] S2. Preparation of catalyst precursor by equal volume impregnation: Calculate the corresponding mass of support according to the molybdenum metal loading of 8-12 wt% and weigh the support. Use the equal volume impregnation method to slowly drip the bimetallic aqueous solution onto the support so that the solution just covers the surface of the support. After impregnation for 2-4 hours, sonicate for 1-2 hours. After sonication, place it in an oven at 100-110℃ and bake for 10-12 hours to obtain the molybdenum-based catalyst precursor.

[0009] S3. Catalyst precursor calcination: The catalyst precursor is ground and placed in a tube furnace, and calcined at 500-700℃ for 5-7 hours under a nitrogen atmosphere to obtain a supported molybdenum-based catalyst.

[0010] Furthermore, in S1, the other metal salt is one or more of nitrates, carbonates, and chlorides.

[0011] Furthermore, the metal element in the nitrate, carbonate, and chloride salt is one or more of iron, copper, nickel, cobalt, cesium, potassium, and sodium.

[0012] Furthermore, in S2, the carrier is one of manganese dioxide, activated carbon, magnesium oxide, niobium pentoxide, aluminum oxide, H-Beta molecular sieve, and silicon dioxide.

[0013] Furthermore, the heating rate of the calcination is 2-4 °C / min.

[0014] Another object of the present invention is to provide an application of a supported molybdenum-based catalyst, characterized in that the supported molybdenum-based catalyst is used in the preparation of furan-based chemicals.

[0015] An application of a supported molybdenum-based catalyst, characterized in that: the supported molybdenum-based catalyst is used in the preparation of furan-like chemicals.

[0016] Furthermore, the preparation of furan-based chemicals using the supported molybdenum-based catalyst includes the following steps:

[0017] Step 1: Weigh out glucose, supported molybdenum-based catalyst, water, and acetylacetone in a mass ratio of 3.6–7.2:1–2:100–200:100–200; and mix water and acetylacetone to prepare a two-phase system.

[0018] Step 2: Add the substrate to the two-phase system to obtain the initial reaction system;

[0019] Step 3: Add the supported molybdenum-based catalyst to the initial reaction system, mix and place in a sealed reaction vessel, heat and stir at 70-150℃ to carry out C-C bond breaking and nucleophilic addition cascade reaction for 1-180 min to obtain furan chemicals.

[0020] The beneficial effects of this invention are:

[0021] The molybdenum-based catalyst designed in this invention has a simple preparation method and high catalytic efficiency. It can realize a complex cascade reaction from glucose to high-value furan chemicals under mild conditions, including the selective cleavage of the C-C bond of glucose to generate C2 glycolaldehyde and C4 erythrose intermediates, and the further nucleophilic addition of the intermediates to acetylacetone to generate furan chemicals 2-methyl-3-acetylfuran and 2-methyl-3-acetyl-5-(1,2-hydroxy)furan. The product yield is high and it has great practical application value.

[0022] This invention can prepare various types of high-value-added furan compounds from inexpensive sugars. It features green and mild reaction conditions, simple catalyst preparation, high conversion efficiency and high yield of furan chemicals. The raw materials are widely available, showing good prospects for industrial application. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart illustrating the preparation process of the supported molybdenum-based catalyst of the present invention.

[0025] Figure 2 This is a flowchart illustrating the preparation process of furan-based chemicals using a supported molybdenum-based catalyst according to the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] A specific method for preparing a supported molybdenum-based catalyst, characterized by comprising the following steps:

[0029] S1. Preparation of bimetallic aqueous solution: Weigh ammonium heptamolybdate tetrahydrate and ferric nitrate metal salt according to the metal molar ratio of 1:0.1, and then use 10% isopropanol solution to dissolve ammonium heptamolybdate tetrahydrate and ferric nitrate metal salt to prepare bimetallic aqueous solution;

[0030] S2. Preparation of catalyst precursor by equal volume impregnation: Weigh manganese dioxide support according to the formula ratio, and slowly drip bimetallic aqueous solution onto manganese dioxide using the equal volume impregnation method so that the solution just covers the surface of manganese dioxide. After impregnation for 2 hours, sonicate for 2 hours. After sonication, place in an oven at 105℃ and bake for 12 hours to obtain molybdenum-based catalyst precursor.

[0031] S3. Catalyst precursor calcination: After grinding the catalyst precursor b, it was placed in a tube furnace and calcined at 550°C for 6 hours under a nitrogen atmosphere to obtain the supported molybdenum-based catalyst A1.

[0032] The specific method for preparing furan-based chemicals using supported molybdenum-based catalysts is as follows:

[0033] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst A1 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was then determined by gas chromatography to be 3.1%.

[0034] Example 2

[0035] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst A2 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was then determined by gas chromatography to be 7.8%.

[0036] The preparation method of molybdenum-based catalyst A2 is the same as that of molybdenum-based catalyst A1 in Example 1, except that the support is activated carbon.

[0037] Example 3:

[0038] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst A3 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was then detected by gas chromatography to be 9.2%.

[0039] The preparation method of molybdenum-based catalyst A3 is the same as that of molybdenum-based catalyst A1 in Example 1, except that the support is magnesium oxide.

[0040] Example 4:

[0041] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst A4 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 12.2% as determined by gas chromatography.

[0042] The preparation method of molybdenum-based catalyst A4 is the same as that of molybdenum-based catalyst A1 in Example 1, except that the support is niobium pentoxide.

[0043] Example 5:

[0044] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst A5 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond breaking and cascade reaction. The yield of 2-methyl-3-acetylfuran was then detected by gas chromatography and found to be 15.4%.

[0045] The preparation method of molybdenum-based catalyst A5 is the same as that of molybdenum-based catalyst A1 in Example 1, except that the support is alumina.

[0046] Example 6:

[0047] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst A6 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond breaking and cascade reaction. The yield of 2-methyl-3-acetylfuran was then detected by gas chromatography and found to be 15.4%.

[0048] The preparation method of molybdenum-based catalyst A6 is the same as that of molybdenum-based catalyst A1 in Example 1, except that the support is H-Beta molecular sieve.

[0049] Example 7:

[0050] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst A7 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 13.7% as determined by gas chromatography.

[0051] The preparation method of molybdenum-based catalyst A7 is the same as that of molybdenum-based catalyst A1 in Example 1, except that the support is silicon dioxide.

[0052] Example 8:

[0053] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B1 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 14.4% by gas chromatography and 16.5% by liquid chromatography.

[0054] The preparation method of molybdenum-based catalyst B1 includes the following steps: weighing ammonium heptamolybdate tetrahydrate and zinc nitrate metal salt at a metal molar ratio of 1:1, and then dissolving ammonium heptamolybdate tetrahydrate and iron nitrate metal salt in 10% isopropanol solution to prepare a bimetallic aqueous solution.

[0055] S2. Preparation of catalyst precursor by equal volume impregnation: Weigh the silica support according to the formula ratio, and slowly drip the bimetallic aqueous solution onto the silica using the equal volume impregnation method so that the solution just covers the surface of the silica. After impregnation for 2 hours, sonicate for 2 hours. After sonication, place it in an oven at 105℃ for 12 hours to obtain the molybdenum-based catalyst precursor.

[0056] S3. Catalyst precursor calcination: The catalyst precursor was ground and placed in a tube furnace, and calcined at 550°C for 6 hours under a nitrogen atmosphere to obtain molybdenum-based catalyst B1.

[0057] Example 9:

[0058] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B2 was added. The mixture was placed in a sealed high-pressure reactor and heated at 130 °C with stirring to carry out C-C bond cleavage and cascade reaction for 120 min. The yield of 2-methyl-3-acetylfuran was 15.1% as determined by gas chromatography and 23.2% as determined by liquid chromatography.

[0059] The preparation method of molybdenum-based catalyst B2 is the same as that of molybdenum-based catalyst B1 in Example 1, except that another metal salt, copper nitrate, is added.

[0060] Example 10:

[0061] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B3 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 19.9% ​​by gas chromatography and 44.6% by liquid chromatography.

[0062] The preparation method of molybdenum-based catalyst B3 is the same as that of molybdenum-based catalyst B1 in Example 1, except that another metal salt, cobalt nitrate, is added.

[0063] Example 11:

[0064] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B4 was added. The mixture was placed in a sealed high-pressure reactor and heated at 130 °C with stirring to carry out C-C bond cleavage and cascade reaction for 120 min. The yield of 2-methyl-3-acetylfuran was 25.3% as determined by gas chromatography and 46.4% as determined by liquid chromatography.

[0065] The preparation method of molybdenum-based catalyst B4 is the same as that of molybdenum-based catalyst B1 in Example 1, except that another metal salt, nickel nitrate, is added.

[0066] Example 12:

[0067] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B5 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 33.5% by gas chromatography and 54.4% by liquid chromatography.

[0068] The preparation method of molybdenum-based catalyst B5 is the same as that of molybdenum-based catalyst B1 in Example 1, except that another metal salt, cesium carbonate, is added.

[0069] Example 13:

[0070] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B6 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 27.1% by gas chromatography and 46.6% by liquid chromatography.

[0071] The preparation method of molybdenum-based catalyst B6 is the same as that of molybdenum-based catalyst B1 in Example 1, except that another metal salt, lithium chloride, is added.

[0072] Example 14:

[0073] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B7 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 30% by gas chromatography and 46.3% by liquid chromatography.

[0074] The preparation method of molybdenum-based catalyst B7 is the same as that of molybdenum-based catalyst B1 in Example 1, except that another metal salt, sodium carbonate, is added.

[0075] Example 15:

[0076] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B8 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 30% by gas chromatography and 45.3% by liquid chromatography.

[0077] The preparation method of molybdenum-based catalyst B8 is the same as that of molybdenum-based catalyst B1 in Example 1, except that another metal salt, potassium carbonate, is added.

[0078] Example 16:

[0079] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst C1 was added. The mixture was placed in a sealed high-pressure reactor and heated at 130 °C with stirring to carry out C-C bond cleavage and cascade reaction for 120 min. The yield of 2-methyl-3-acetylfuran was 15.1% as determined by gas chromatography and 20.4% as determined by liquid chromatography.

[0080] The preparation method of molybdenum-based catalyst C1 is the same as that of molybdenum-based catalyst B5 in Example 12, except that the molar ratio of added molybdenum and cesium is 1:0.1.

[0081] Example 17:

[0082] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst C2 was added. The mixture was placed in a sealed high-pressure reactor and heated at 130 °C with stirring to carry out C-C bond cleavage and cascade reaction for 120 min. The yield of 2-methyl-3-acetylfuran was 22.5% as determined by gas chromatography and 28.6% as determined by liquid chromatography.

[0083] The preparation method of molybdenum-based catalyst C2 is the same as that of molybdenum-based catalyst B5 in Example 12, except that the molar ratio of added molybdenum and cesium is 1:0.25.

[0084] Example 18:

[0085] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst C3 was added. The mixture was placed in a sealed high-pressure reactor and heated at 130 °C with stirring to carry out C-C bond cleavage and cascade reaction for 120 min. The yield of 2-methyl-3-acetylfuran was 29.6% as determined by gas chromatography and 44.1% as determined by liquid chromatography.

[0086] The preparation method of molybdenum-based catalyst C3 is the same as that of molybdenum-based catalyst B5 in Example 12, except that the molar ratio of added molybdenum and cesium is 1:0.5.

[0087] Example 19:

[0088] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst C4 was added. The mixture was placed in a sealed high-pressure reactor and heated at 130 °C with stirring to carry out C-C bond cleavage and cascade reaction for 120 min. The yield of 2-methyl-3-acetylfuran was 31.1% as determined by gas chromatography and 42% as determined by liquid chromatography.

[0089] The preparation method of molybdenum-based catalyst C4 is the same as that of molybdenum-based catalyst B5 in Example 12, except that the molar ratio of added molybdenum and cesium is 1:0.75.

[0090] Example 20

[0091] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst C5 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 31.1% by gas chromatography and 42% by liquid chromatography.

[0092] The preparation method of molybdenum-based catalyst C5 is the same as that of molybdenum-based catalyst B5 in Example 12, except that the molar ratio of added molybdenum and cesium is 1:1.5.

[0093] Example 21:

[0094] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B5 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 70 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 6% by gas chromatography and 6.8% by liquid chromatography.

[0095] Example 22:

[0096] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B5 was added and mixed in a sealed high-pressure reactor. The mixture was heated at 90 °C and stirred to carry out C-C bond cleavage and cascade reaction for 120 min. The yield of 2-methyl-3-acetylfuran was 16.8% by gas chromatography and 30.9% by liquid chromatography.

[0097] Example 23:

[0098] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B5 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 110 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 25.7% by gas chromatography and 39.6% by liquid chromatography.

[0099] Example 24:

[0100] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B5 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 150 °C for 120 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 31.7% by gas chromatography and 49.3% by liquid chromatography.

[0101] Example 25:

[0102] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B5 was added. The mixture was placed in a sealed high-pressure reactor and heated at 130 °C with stirring to carry out C-C bond cleavage and cascade reaction for 10 min. The yield of 2-methyl-3-acetylfuran was 20.6% as determined by gas chromatography and 26.2% as determined by liquid chromatography.

[0103] Example 26:

[0104] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B5 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 30 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 28.8% by gas chromatography and 42.9% by liquid chromatography.

[0105] Example 27:

[0106] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B5 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 60 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 30.2% by gas chromatography and 43.8% by liquid chromatography.

[0107] Example 28:

[0108] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B5 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 90 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 33.5% by gas chromatography and 64.6% by liquid chromatography.

[0109] Example 29:

[0110] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B5 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 150 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 33.2% by gas chromatography and 56.6% by liquid chromatography.

[0111] Example 30:

[0112] 0.18 g of glucose was added to a two-phase system of 5 mL of water and 5 mL of acetylacetone, and then 0.05 g of molybdenum-based catalyst B5 was added and mixed in a sealed high-pressure reactor. The mixture was heated and stirred at 130 °C for 180 min to carry out C-C bond cleavage and cascade reaction. The yield of 2-methyl-3-acetylfuran was 32.4% by gas chromatography and 46.3% by liquid chromatography.

[0113] The comparison table below can be obtained from Examples 1-7.

[0114]

[0115]

[0116] Comparison Table 1

[0117] As shown in Table 1, the reaction of the molybdenum-iron bimetallic component loaded on different supports was analyzed. It can be seen that A7 (Mo-Fe-SiO2) has the best effect on the cleavage of glucose C-C bonds, and the yield of 2-methyl-3-acetylfuran reaches 19.7%.

[0118] The comparison table shown below can be obtained from Example 8-15.

[0119]

[0120]

[0121] Comparison Table 2

[0122] As shown in Table 2, the reaction of molybdenum metal components with other metals supported on silica supports was analyzed. It can be seen that molybdenum and alkali metal catalysts (B5-B8) generally showed good effects on the cleavage of C-C bonds in glucose. Overall, the yield of 2-methyl-3-acetylfuran was close to 30%, and the yield of 2-methyl-3-acetyl-5-(1,2-hydroxy)furan was also 46%. This indicates that the addition of alkali metals is beneficial for the selective cleavage of glucose bonds. Among these, Cs metal showed the best effect.

[0123] The comparison table shown below can be obtained from Examples 16-19.

[0124]

[0125] Comparison Table 3

[0126] As shown in Table 3, the Mo-Cs-SiO2 metal ratio was screened, and it was found that the yields of 2-methyl-3-acetylfuran and 2-methyl-3-acetyl-5-(1,2-hydroxy)furan increased with the increase of the Mo-Cs ratio. Furthermore, the effect did not change significantly when the Mo-Cs metal molar ratio was 1:1.5. Therefore, the optimal MoCs metal molar ratio is 1:1 (catalyst B5).

[0127] The comparison table below can be obtained from Examples 21-24.

[0128]

[0129] Comparison Table 4

[0130] As shown in Table 4, the reaction temperature was screened based on Mo1-Cs1-SiO2. It can be seen that the yields of both products, 2-methyl-3-acetylfuran and 2-methyl-3-acetyl-5-(1,2-hydroxy)furan, increase with increasing temperature, but the product yield decreases slightly at 150℃. Therefore, the optimal reaction temperature is 130℃ (catalyst B5).

[0131] The comparison table shown below can be obtained from Examples 25-30.

[0132]

[0133]

[0134] Comparison Table 5

[0135] As shown in Table 5, the reaction time was screened based on Mo1-Cs1-SiO2. With increasing reaction time, the yields of the two products, 2-methyl-3-acetylfuran and 2-methyl-3-acetyl-5-(1,2-hydroxy)furan, also increased. However, the yield of 2-methyl-3-acetyl-5-(1,2-hydroxy)furan decreased after 180 min. Therefore, the optimal reaction time is 150 min.

Claims

1. A method for preparing a supported molybdenum-based catalyst for the preparation of furan chemicals from glucose, characterized in that, Includes the following steps: S1. Preparation of bimetallic aqueous solution: Weigh ammonium heptamolybdate tetrahydrate and another metal salt according to a metal molar ratio of 1:0.5~1, and then use 8~12% isopropanol solution to dissolve the ammonium heptamolybdate tetrahydrate and the metal salt to prepare a bimetallic aqueous solution. S2. Preparation of catalyst precursor by equal volume impregnation: Calculate the corresponding mass of support according to the molybdenum metal loading of 8~12 wt% and weigh the support. Use the equal volume impregnation method to slowly drip the bimetallic aqueous solution onto the support so that the solution just covers the surface of the support. After impregnation for 2~4 hours, sonicate for 1~2 hours. After sonication, place it in an oven at 100~110℃ and bake for 10~12 hours to obtain the molybdenum-based catalyst precursor. S3. Catalyst precursor calcination: The catalyst precursor is ground and placed in a tube furnace and calcined at 500~700℃ for 5~7h under nitrogen atmosphere to obtain a supported molybdenum-based catalyst. In S1, the other metal salt is one or more of nitrates, carbonates, and chlorides; The metal element in the nitrate, carbonate and chloride salts is one or more of nickel, cobalt, cesium, potassium and sodium; In S2, the support is one of niobium pentoxide, alumina, H-Beta molecular sieve, and silicon dioxide.

2. The method for preparing a supported molybdenum-based catalyst for the preparation of furan-based chemicals from glucose according to claim 1, characterized in that: The heating rate during roasting is 2~4℃ / min.

3. The application of the supported molybdenum-based catalyst prepared by the method for preparing a supported molybdenum-based catalyst for the preparation of furan chemicals from glucose according to any one of claims 1-2 in the preparation of furan chemicals.

4. The application according to claim 3, characterized in that: The preparation of furan-based chemicals using the supported molybdenum-based catalyst includes the following steps: Step 1: Weigh out glucose, supported molybdenum-based catalyst, water, and acetylacetone in a mass ratio of 3.6~7.2:1:100~200:100~200; and mix water and acetylacetone to prepare a two-phase system. Step 2: Add the substrate to the two-phase system to obtain the initial reaction system; Step 3: Add the supported molybdenum-based catalyst to the initial reaction system, mix and place in a sealed reaction vessel, heat and stir at 90~150℃ to carry out C-C bond breaking and nucleophilic addition cascade reaction for 30~180 min to obtain furan chemicals.

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