Molybdenum-based catalyst, preparation method and application thereof and method for preparing fructose from glucose

Abstract

The invention relates to the technical field of supported catalysts and the technical field of glucose catalytic preparation of fructose, in particular to a molybdenum-based catalyst, a preparation method and application thereof and a method for preparing fructose from glucose, the molybdenum-based catalyst comprises a carrier and an active component, the carrier is a molecular sieve, and the active component is molybdenum oxide; wherein the percentage content of molybdenum oxide in the molybdenum-based catalyst is 10-50%. The molybdenum-based catalyst can be used for continuous catalytic isomerization of glucose, generation of fructose products is remarkably improved, meanwhile, the molybdenum-based catalyst is prepared through an impregnation method, the steps are simple, operation is convenient, the molybdenum-based catalyst is suitable for industrial large-scale production, further, operation is easy and convenient when the molybdenum-based catalyst is used for catalyzing glucose to prepare fructose, reaction conditions are mild, and the method is suitable for industrial large-scale production. And the production process can be continuously carried out, is green and efficient, and has high economic benefits and very wide application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of supported catalysts and the technical field of preparing fructose by catalysis of glucose, and in particular to a molybdenum-based catalyst and a preparation method and application thereof, and a method for preparing fructose by using glucose. Background Art

[0002] Fructose is a common ketohexose with extremely high application value. It can be widely used in the preparation of fructose syrup, food, medicine and other fields. Fructose can also be used to synthesize higher-value fine chemicals and biofuel precursors, such as 5-hydroxymethylfurfural, levulinic acid, fructose glycosides and low-carbon alkanes. Glucose is abundant and inexpensive, and is mainly found in cellulose plants, such as corn, straw, and beets. The use of glucose conversion to produce fructose has broad application prospects.

[0003] At present, fructose mainly comes from the enzymatic hydrolysis of starch or glucose, which generates syrup containing fructose and glucose under the action of dilute acid or enzyme, and then is converted into fructose by bioisomerase. The bioenzymatic method has the advantage of mild reaction, but the activity and stability of the enzyme affect the occurrence of the reaction. Chemical catalysis of glucose to produce fructose has the advantages of controllable reaction, high conversion efficiency and simple process. In recent years, there have been many studies on the conversion of glucose to fructose using catalysts such as liquid alkali and solid alkali, and most of them are carried out in reactors.

[0004] The literature (Catalysis Science & Technology, 2020, 10: 3232-3246.) reported the use of alkali metal (Na and K) or alkaline earth metal (Ca and Mg) solid base catalysts with a layered MFI structure to catalyze the production of fructose from glucose. Glucose has a good conversion in the aqueous phase system, and the glucose conversion rate can reach 45% after 2 hours of reaction at 100°C, the fructose selectivity reaches 65%, and the fructose yield reaches 29.3%. In view of the research methods currently reported, most of them belong to intermittent production, and there are problems such as low conversion of sugar raw materials and low fructose yield. Therefore, the invention of a method for continuously and effectively isomerizing glucose to produce fructose has important technical reference value for improving the continuous conversion of glucose and the continuous output of fructose. Summary of the invention

[0005] The purpose of the present invention is to provide a molybdenum-based catalyst and its preparation method and application, and a method for preparing fructose from glucose in view of the problems of low sugar raw material conversion rate and low fructose yield in the prior art. The molybdenum-based catalyst can continuously catalyze the isomerization of glucose and significantly improve the generation of fructose products. At the same time, the molybdenum-based catalyst of the present invention is prepared by an impregnation method, which has simple steps and convenient operation, and is suitable for industrial mass production. Furthermore, the operation of catalyzing glucose to prepare fructose using the molybdenum-based catalyst of the present invention is simple, the reaction conditions are mild, the production process occurs sustainably, it is green and efficient, has high economic benefits, and has broad application prospects.

[0006] In order to achieve the above-mentioned object, in the first aspect, the present invention provides a molybdenum-based catalyst, characterized in that the molybdenum-based catalyst comprises a carrier and an active component, the carrier is a molecular sieve, and the active component is molybdenum oxide; wherein,

[0007] The percentage of molybdenum oxide in the molybdenum-based catalyst is 10-50%.

[0008] In a second aspect, the present invention provides a method for preparing a molybdenum-based catalyst, the preparation method comprising: mixing a molybdenum source and a molecular sieve modified by alkali treatment in the presence of a solvent, impregnating, drying, and calcining.

[0009] Preferably, the molybdenum source is molybdic acid and / or molybdate.

[0010] Preferably, the molybdate is selected from one or two or more of ammonium molybdate, ammonium phosphomolybdate, sodium molybdate and sodium phosphomolybdate.

[0011] More preferably, the molecular sieve is selected from one or two or more of MCM-22, MCM-41, ZSM-5, SPAO-11 and SPAO-34.

[0012] More preferably, the solvent is water.

[0013] Preferably, the weight ratio of the molybdenum source to the molecular sieve is 0.1-0.7:1, wherein the molybdenum source is calculated based on the mass of molybdenum oxide.

[0014] Preferably, the mixing conditions include: stirring time of 3-6 hours, and stirring rate of 300-800 rpm.

[0015] Preferably, the immersion conditions include: temperature of 15-30°C and time of 6-12h.

[0016] More preferably, the drying conditions include: a temperature of 100-120° C. and a time of 12-24 hours.

[0017] Further preferably, the calcination conditions include: temperature of 400-750° C. and time of 2-6 h.

[0018] Preferably, the alkali treatment method comprises: dissolving the molecular sieve in a solvent, adding an alkaline agent, stirring, washing, drying, and calcining.

[0019] Preferably, the molecular sieve is selected from one or two or more of MCM-22, MCM-41, ZSM-5, SPAO-11 and SPAO-34.

[0020] More preferably, the alkaline agent is selected from one or two or more of ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate, ammonia water or ethanolamine.

[0021] More preferably, the solvent is water.

[0022] More preferably, the weight ratio of the molecular sieve to the alkaline agent is 1:0.01-0.05.

[0023] Preferably, the stirring conditions include: stirring time of 1-3h, stirring rate of 300-800rpm.

[0024] Preferably, the water washing conditions include: washing with a detergent until the pH is 6-8.

[0025] More preferably, the detergent is water.

[0026] Further preferably, the drying conditions include: temperature of 100-120° C. and time of 12-24 h.

[0027] More preferably, the calcination conditions include: temperature of 300-650° C. and time of 2-6 h.

[0028] In a third aspect, the present invention provides a molybdenum-based catalyst prepared by the preparation method described in the second aspect.

[0029] In a fourth aspect, the present invention provides a use of the molybdenum-based catalyst described in the first aspect or the third aspect in catalyzing the production of fructose from glucose.

[0030] In a fifth aspect, the present invention provides a method for producing fructose from glucose, the method comprising: placing a molybdenum-based catalyst in a fixed bed reactor, using a high-pressure flow pump to input a glucose solution, and performing a catalytic reaction, wherein:

[0031] The molybdenum-based catalyst is the molybdenum-based catalyst described in the first aspect or the third aspect.

[0032] Preferably, when the amount of the platinum-based catalyst is 0.3-0.8 g, the concentration of the glucose solution is 8-12 mg / mL.

[0033] More preferably, the input conditions include: liquid space velocity is 10-20h-1.

[0034] Further preferably, the conditions of the catalytic reaction include: temperature of 100-120° C. and time of 0.5-1.5 h.

[0035] In the above technical scheme, the molybdenum-based catalyst of the present invention uses an alkaline reagent to modify the molecular sieve carrier, which effectively regulates the distribution and content of the acid-base groups of the molecular sieve, which is beneficial to regulate the interaction between the molecular sieve carrier and the active component molybdenum oxide in the molybdenum-based catalyst, and further promotes the continuous catalytic isomerization of glucose into fructose in the reaction system for catalyzing glucose to prepare fructose.

[0036] At the same time, the molybdenum-based catalyst of the present invention is prepared by an impregnation method, which has the advantages of simple operation and mild conditions and is suitable for industrial mass production.

[0037] Furthermore, the molybdenum-based catalyst of the present invention is applied to a reaction system for catalyzing glucose to prepare fructose, which significantly improves the continuous conversion capacity of glucose, reduces the occurrence of side reactions, and improves the continuous production of fructose. At the same time, the use of a solid reactor significantly simplifies product separation and purification, significantly reduces production costs, and the molybdenum-based catalyst of the present invention has a high reusability, a green process, and has good application prospects.

[0038] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0039] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0040] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0041] In a first aspect, the present invention provides a molybdenum-based catalyst, characterized in that the molybdenum-based catalyst comprises a carrier and an active component, the carrier is a molecular sieve, and the active component is molybdenum oxide; wherein the percentage of molybdenum oxide in the molybdenum-based catalyst is 10-50%.

[0042] The molybdenum-based catalyst of the present invention uses an alkaline reagent to modify the molecular sieve carrier, which effectively regulates the distribution and content of the acid-base groups of the molecular sieve, is beneficial to regulating the interaction between the molecular sieve carrier and the active component molybdenum oxide in the molybdenum-based catalyst, and further promotes the continuous catalytic isomerization of glucose into fructose in the reaction system for catalyzing glucose to prepare fructose.

[0043] In a second aspect, the present invention provides a method for preparing a molybdenum-based catalyst, the preparation method comprising: mixing a molybdenum source and a molecular sieve modified by alkali treatment in the presence of a solvent, impregnating, drying, and calcining.

[0044] The molybdenum-based catalyst of the present invention is prepared by an impregnation method, which has the advantages of simple operation and mild conditions and is suitable for industrial mass production.

[0045] In a preferred embodiment of the present invention, in order to promote uniform dispersion and shaping of the molybdenum active component on the surface of the carrier, the molybdenum source is molybdic acid and / or molybdate.

[0046] In a preferred embodiment of the present invention, in order to ensure the effective generation of the active component molybdenum oxide, the molybdate is selected from one or two or more of ammonium molybdate, ammonium phosphomolybdate, sodium molybdate and sodium phosphomolybdate.

[0047] In a preferred embodiment of the present invention, in order to regulate the adsorption, dispersion and interaction between the active component on the carrier surface and the carrier, the molecular sieve is selected from one or two or more of MCM-22, MCM-41, ZSM-5, SPAO-11 and SPAO-34.

[0048] In a preferred embodiment of the present invention, in order to promote the full dissolution of reactant molecules and the effective dissociation of intermediate reactants, the solvent is water.

[0049] In a preferred embodiment of the present invention, in order to regulate the uniform dispersion and formation of the active components on the carrier surface, the weight ratio of the molybdenum source to the molecular sieve is 0.1-0.7:1, wherein the molybdenum source is calculated by the mass of molybdenum oxide.

[0050] In a preferred embodiment of the present invention, in order to promote the complete dissolution of the active component precursor in the solvent and the sufficient dispersion on the surface of the carrier, the mixing conditions include: stirring time of 3-6h, stirring rate of 300-800rpm.

[0051] In a preferred embodiment of the present invention, in order to regulate the interaction between molybdic acid or molybdenum salt and the carrier, the impregnation conditions include: temperature of 15-30° C. and time of 6-12 h.

[0052] In a preferred embodiment of the present invention, in order to promote and regulate the formation of molybdic acid or molybdenum salt on the surface of the carrier and in the pores, the drying conditions include: a temperature of 100-120° C. and a time of 12-24 h.

[0053] In a preferred embodiment of the present invention, in order to regulate the effective generation and distribution state of molybdenum oxide, the calcination conditions include: a temperature of 400-750° C. and a time of 2-6 hours.

[0054] In a preferred embodiment of the present invention, in order to adjust the surface group characteristics of the molecular sieve and the interaction with the active component, the alkali treatment method includes: dissolving the molecular sieve in a solvent, adding an alkaline agent, stirring, washing, drying, and calcining.

[0055] In a preferred embodiment of the present invention, in order to regulate the adsorption and dispersion of molybdenum oxide on the surface and in the pores of the carrier and the effective diffusion of the product, the molecular sieve is selected from one or two or more of MCM-22, MCM-41, ZSM-5, SPAO-11 and SPAO-34.

[0056] In a preferred embodiment of the present invention, in order to adjust the surface acid-base properties of the molecular sieve and the adsorption and formation between the active components, the alkaline agent is selected from one or two or more of ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate, ammonia or ethanolamine.

[0057] In a preferred embodiment of the present invention, in order to promote the full dissolution of reactant molecules and the interaction between the catalyst and the reactants, the solvent is water.

[0058] In a preferred embodiment of the present invention, in order to adjust the type and quantity of the molecular sieve surface groups, the ratio of the molecular sieve to the alkaline agent is 1:0.01-0.05.

[0059] In a preferred embodiment of the present invention, in order to promote sufficient adsorption and uniform dispersion of the active components, the stirring conditions include: a stirring time of 1-3 hours and a stirring rate of 300-800 rpm.

[0060] In a preferred embodiment of the present invention, in order to remove the influence of impurities on the active components of the catalyst, the water washing conditions include: washing with a detergent until the pH is 6-8.

[0061] In a preferred embodiment of the present invention, in order to effectively filter out soluble impurities, the detergent is water.

[0062] In a preferred embodiment of the present invention, in order to regulate the adsorption and dispersion of the molybdenum salt on the surface of the carrier, the drying conditions include: a temperature of 100-120° C. and a time of 12-24 h.

[0063] In a more preferred embodiment of the present invention, in order to adjust the type and generation of the active component molybdenum oxide, the calcination conditions include: a temperature of 300-650° C. and a time of 2-6 hours.

[0064] In a third aspect, the present invention provides a molybdenum-based catalyst prepared by the preparation method described in the second aspect.

[0065] In a fourth aspect, the present invention provides a use of the molybdenum-based catalyst described in the first aspect or the third aspect in catalyzing the production of fructose from glucose.

[0066] In a fifth aspect, the present invention provides a method for producing fructose from glucose, the method comprising: placing a molybdenum-based catalyst in a fixed bed reactor, using a high-pressure flow pump to input a glucose solution, and performing a catalytic reaction, wherein:

[0067] The molybdenum-based catalyst is the molybdenum-based catalyst described in the first aspect or the third aspect.

[0068] The molybdenum-based catalyst of the present invention is applied to a reaction system for catalyzing glucose to prepare fructose, which significantly improves the continuous conversion capacity of glucose, reduces the occurrence of side reactions, and improves the continuous production of fructose. At the same time, the solid reactor is used to significantly simplify product separation and purification, significantly reduce production costs, and the molybdenum-based catalyst of the present invention has a high reusability, the process is green and environmentally friendly, and has a good application prospect.

[0069] In a preferred embodiment of the present invention, in order to promote the isomerization conversion of glucose molecules, when the amount of the molybdenum-based catalyst is 0.3-0.8 g, the concentration of the glucose solution is 8-12 mg / mL.

[0070] In a preferred embodiment of the present invention, in order to regulate the contact and interaction between the catalyst and the reactant molecules, the input conditions include: the liquid space velocity is 10-20h-1.

[0071] In a preferred embodiment of the present invention, in order to prevent high-temperature decomposition or polymerization of reactant or product molecules, the conditions of the catalytic reaction include: a temperature of 100-120° C. and a time of 0.5-1.5 h.

[0072] In a preferred embodiment of the present invention, room temperature refers to a temperature of 15-30°C.

[0073] In a preferred embodiment of the present invention, neutral refers to a pH of 6-8.

[0074] In a preferred embodiment of the present invention, distilled water, ultrapure water or deionized water can be used for washing.

[0075] The present invention will be described in detail below by way of examples. In the following examples, the drugs and medicaments are all conventional commercial products.

[0076] Preparation Example 1

[0077] Dissolve 10 g of molecular sieve MCM-22 in 30 ml of deionized water and stir for 1.0 h, add 1 g of ammonia water, stir for 2 h, wash with water until neutral, dry at 110° C. for 24 h, place in a muffle furnace, roast at 500° C. for 2 h, and then cool to obtain a molecular sieve modified by alkali treatment, recorded as A1.

[0078] Preparation Example 2

[0079] The method of Preparation Example 1 was followed, except that "10 g molecular sieve MCM-22" was replaced by "10 g molecular sieve MCM-41" and other conditions remained unchanged to obtain a molecular sieve modified by alkali treatment, which was recorded as A2.

[0080] Preparation Example 3

[0081] The method of Preparation Example 1 was followed, except that "ammonia water" was replaced by "ammonium bicarbonate" and other conditions remained unchanged, to obtain a molecular sieve modified by alkali treatment, which was recorded as A3.

[0082] Example 1

[0083] Weigh 2.1 g of ammonium molybdate and fully dissolve it in 10 ml of water, then add 5 g of the alkali-treated modified molecular sieve A1 obtained in Preparation Example 1, stir at 600 rpm for 3 h, soak for 6 h, dry at 110 ° C for 24 h, and then place in a muffle furnace and roast at 550 ° C for 3 h and then cool to obtain a molybdenum-based catalyst (MoO 3 / MCM-22), recorded as Cat 1.

[0084] Example 2

[0085] The method of Example 1 was followed, except that "Preparation Example 1 prepared alkali-treated modified molecular sieve A1" was replaced by "Preparation Example 2 prepared alkali-treated modified molecular sieve A2", and other conditions remained unchanged to prepare the corresponding molybdenum-based catalyst, recorded as Cat 2.

[0086] Example 3

[0087] The method of Example 1 was followed, except that "Preparation Example 1 prepared alkali-treated modified molecular sieve A1" was replaced by "Preparation Example 3 prepared alkali-treated modified molecular sieve A3", and other conditions remained unchanged to prepare the corresponding molybdenum-based catalyst, recorded as Cat 3.

[0088] Example 4

[0089] The method of Example 1 was followed, except that in step (1), "calcining at 550°C" was replaced by "calcining at 750°C", and other conditions remained unchanged, to obtain the corresponding molybdenum-based catalyst, which was recorded as Cat 4.

[0090] Comparative Example 1

[0091] 2.1 g of ammonium molybdate was weighed and dry-mixed with 5 g of the alkali-treated modified molecular sieve A1 obtained in Preparation Example 1 for 3 h, and then placed in a muffle furnace and calcined at 550° C. for 3 h and then cooled to obtain a molybdenum-based catalyst, which was recorded as Cat A.

[0092] Comparative Example 2

[0093] The method of Example 1 was followed, except that "2.1 g of ammonium molybdate" was replaced by "2.36 g of ammonium tungstate" and other conditions remained unchanged, to obtain the corresponding catalyst, which was recorded as CatB.

[0094] Comparative Example 3

[0095] The method of Example 1 was followed, except that "2.1 g of ammonium molybdate" was replaced by "1.63 g of ammonium chromate" and other conditions remained unchanged, to obtain the corresponding catalyst, which was recorded as Cat C.

[0096] Application Example 1

[0097] The specific steps of the performance evaluation test for the catalytic glucose to fructose reaction of the present invention are as follows:

[0098] 0.5 g of the molybdenum-based catalyst Cat1 obtained in Example 1 was weighed and placed in a fixed bed reactor. A 10 mg / ml glucose solution was input using a high-pressure flow pump. The liquid space velocity was controlled to 15 h-1, the reaction temperature was controlled to 110°C, and the reaction time was 1 hour. After the reaction was completed, the reaction solution was cooled and the product was analyzed using a high performance liquid chromatograph (HPLC).

[0099] Application Example 2

[0100] The method of Application Example 1 was followed, except that the catalyst Cat 1 was replaced by Cat 3-4 and Cat AC, respectively, and the other steps and conditions were the same.

[0101] Application Example 3

[0102] The method of Application Example 1 was followed, except that "liquid space velocity was controlled to be 15 h-1" was replaced by "liquid space velocity was controlled to be 0.06 h-1", and the other steps and conditions were the same.

[0103] Application Example 4

[0104] The method of Application Example 3 is followed, except that the catalyst Cat 1 is replaced by the catalyst Cat 2, and the other steps and conditions are the same.

[0105] The catalytic performances of the above application examples 1-4 are shown in Table 1.

[0106] Table 1 Performance of glucose in producing lactic acid under different catalysts

[0107]

[0108] From the above and Table 1, it can be seen that the molybdenum-based catalysts prepared in Examples 1-4 of the present invention have a glucose conversion rate of up to 48.6% and a fructose yield of up to 36.9% in the reaction of catalyzing glucose to produce fructose.

[0109] At the same time, in Comparative Example 1, the same molecular sieve as Example 1 was used as a carrier and the same molybdenum source was used to prepare a molybdenum-based catalyst, but the impregnation method of the present invention was not used. In the reaction of catalyzing glucose to produce fructose, the glucose conversion rate was only 21.9%, and the fructose yield was 7.1%. In the reaction of catalyzing glucose to produce fructose, the molybdenum-based catalyst prepared by the impregnation method of the present invention had a glucose conversion rate of at least 28.4%, and a fructose yield of at least 23.1%, both of which were higher than the catalytic performance of the catalyst prepared in Comparative Example 1, indicating that the molybdenum-based catalyst prepared by the impregnation method of the present invention has significantly better catalytic performance than the molybdenum-based catalyst prepared in Comparative Example 1.

[0110] And it can be seen from the data in Table 1 that the catalysts in Comparative Examples 2-3 do not use a molybdenum source as the active component of the catalyst, but use a tungsten source and a chromium source as the active components of the catalyst. The catalytic activity of the obtained catalysts on glucose is much lower than that of the catalyst prepared by using a molybdenum source as the active component of the catalyst in the present invention, indicating that the molybdenum-based catalyst prepared by the material of the present invention has better performance in catalyzing the preparation of fructose from glucose than catalysts of other elements.

[0111] Application Example 3-4 mainly regulates the contact time and reaction effect between the active components of the catalyst and the reactant molecules. From the data obtained in Table 1, it can be seen that the greater the feed space velocity of glucose, the shorter the contact time between the reactants, and the lower the effect of the catalytic reaction.

[0112] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0113] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0114] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A platinum-based catalyst, characterized in that The molybdenum-based catalyst comprises a carrier and an active component, wherein the carrier is a molecular sieve and the active component is molybdenum oxide; The percentage of molybdenum oxide in the molybdenum-based catalyst is 10-50%.

2. A method for preparing a molybdenum-based catalyst, characterized in that: The preparation method comprises: mixing a molybdenum source and a molecular sieve modified by alkali treatment in the presence of a solvent, impregnating, drying and calcining.

3. The preparation method according to claim 2, characterized in that: The molybdenum source is molybdic acid and / or molybdate; Preferably, the molybdate is selected from one or two or more of ammonium molybdate, ammonium phosphomolybdate, sodium molybdate and sodium phosphomolybdate; More preferably, the molecular sieve is one or two or more selected from MCM-22, MCM-41, ZSM-5, SPAO-11 and SPAO-34; More preferably, the solvent is water.

4. The preparation method according to claim 2 or 3, characterized in that: The weight ratio of the molybdenum source to the molecular sieve is 0.1-0.7:1, wherein the molybdenum source is calculated based on the mass of molybdenum oxide.

5. The preparation method according to any one of claims 2 to 4, characterized in that: The mixing conditions include: stirring time of 3-6h, stirring rate of 300-800rpm; Preferably, the immersion conditions include: temperature of 15-30°C, time of 6-12h; More preferably, the drying conditions include: temperature of 100-120°C and time of 12-24h; Further preferably, the calcination conditions include: temperature of 400-750° C. and time of 2-6 h.

6. The preparation method according to any one of claims 2 to 5, characterized in that: The alkali treatment method comprises: dissolving the molecular sieve in a solvent, adding an alkaline agent, stirring, washing, drying, and calcining; Preferably, the molecular sieve is selected from one or two or more of MCM-22, MCM-41, ZSM-5, SPAO-11 and SPAO-34; More preferably, the alkaline agent is selected from one or two or more of ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate, ammonia or ethanolamine; Further preferably, the solvent is water; More preferably, the weight ratio of the molecular sieve to the alkaline agent is 1:0.01-0.

05.

7. The preparation method according to claim 6, characterized in that: The stirring conditions include: stirring time of 1-3h, stirring rate of 300-800rpm; Preferably, the water washing conditions include: washing with a detergent until the pH is 6-8; More preferably, the detergent is water; Further preferably, the drying conditions include: temperature of 100-120°C and time of 12-24h; More preferably, the calcination conditions include: temperature of 300-650° C. and time of 2-6 h.

8. A molybdenum-based catalyst prepared according to the preparation method according to any one of claims 2 to 7.

9. Use of the molybdenum-based catalyst according to claim 1 or claim 8 in catalyzing the production of fructose from glucose.

10. A method for preparing fructose from glucose, characterized in that: The method comprises: placing a molybdenum-based catalyst in a fixed bed reactor, using a high-pressure flow pump to input a glucose solution, and performing a catalytic reaction, wherein: The molybdenum-based catalyst is the molybdenum-based catalyst described in claim 1 or claim 8; Preferably, when the amount of the molybdenum-based catalyst is 0.3-0.8 g, the concentration of the glucose solution is 8-12 mg / mL; More preferably, the input conditions include: liquid space velocity of 10-20h-1; Further preferably, the conditions of the catalytic reaction include: temperature of 100-120° C. and time of 0.5-1.5 h.

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