Oxidative dehydrogenation catalyst as well as preparation method and application thereof

Abstract

The invention relates to the field of catalysis, in particular to an oxidative dehydrogenation catalyst and a preparation method and application thereof. A crystal phase structure of the oxidative dehydrogenation catalyst contains a spinel phase with a chemical formula of AB2O4, a gamma-ferric oxide phase and group IIIB metal sulfide, the particle sizes of the spinel phase and the gamma-ferric oxide phase are respectively 1-100 nanometers. The spinel and iron oxide nanoparticles in the oxidative dehydrogenation catalyst are small in size, so that the adsorption of reaction products by the pore surfaces of the oxidative dehydrogenation catalyst is reduced, and the activity of the oxidative dehydrogenation catalyst under the condition of low water ratio is improved.

Description

Technical Field

[0001] The invention relates to the field of catalysis, and in particular to an oxidative dehydrogenation catalyst and a preparation method and application thereof. Background Art

[0002] Butadiene is a basic raw material for petrochemical industry and can be copolymerized with various compounds to produce various synthetic rubbers and synthetic resins. At present, butadiene is mainly obtained by extracting and separating C4 from ethylene produced by steam cracking in refineries. Butene oxidative dehydrogenation is a process with butadiene as the target product. It can convert butene used in civilian fuel into high-value-added butadiene. This production technology is an important supplement to C4 extraction and separation technology.

[0003] Various catalytic systems, such as the Mo-Bi system, Sn-P-Li system, and Fe salt system, can be used for the oxidative dehydrogenation of butene to produce butadiene. Although the water ratio of the Mo-Bi system is as low as 6 to 8, its selectivity is low and a large amount of organic oxygen-containing by-products are produced. The Sn-P-Li system has high activity, but the operating conditions are relatively harsh, the water-to-olefin ratio is as high as 30 or more, and the energy consumption is very high. Iron-based catalysts are currently the most widely used catalysts for the oxidative dehydrogenation of butene. Their advantages are good stability and relatively few oxidation by-products, but their water-to-olefin ratio is between 12 and 16, the production process has high energy consumption, and a large amount of wastewater, resulting in high production costs.

[0004] Since the invention of the iron-based catalyst for the oxidative dehydrogenation of butene, it has undergone many generations of improvements and its performance has been continuously improved. The existing use of foamed silicon carbide structured carriers to load the ferrite catalytic active components can enhance the mass transfer and heat transfer of the oxidative dehydrogenation reaction under the condition of a water ratio of 6; the addition of vanadium-containing heteropoly acids can promote the dehydrogenation performance of molybdenum-bismuth catalysts under the condition of a water ratio of 2-8. However, to date, a large amount of steam medium is still required in the industrial oxidative dehydrogenation reaction of butene. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem that the oxidative dehydrogenation catalyst in the prior art has low catalytic activity under low water ratio conditions (≤6), and to provide an oxidative dehydrogenation catalyst and a preparation method and application thereof, wherein the oxidative dehydrogenation catalyst has high catalytic activity.

[0006] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides an oxidative dehydrogenation catalyst, the crystal phase structure of which contains a spinel phase and a γ-iron oxide phase with a chemical formula of AB2O4, and a Group IIIB metal sulfide; the particle sizes of the spinel phase and the γ-iron oxide phase are respectively 1-100 nanometers.

[0007] The second aspect of the present invention provides a method for preparing the oxidative dehydrogenation catalyst described in the first aspect, the preparation method comprising: mixing source A, source B and a preferred first high molecular organic matter in a solvent, adding an inorganic base, group IIIB metal sulfide and a second high molecular organic matter for co-precipitation, aging, washing, solid-liquid separation, and calcination.

[0008] The third aspect of the present invention provides an application of the oxidative dehydrogenation catalyst described in the first aspect in the preparation of a catalyst for oxidative dehydrogenation of butene to butadiene.

[0009] Through the above technical solution, the present invention has the following advantages:

[0010] The spinel and iron oxide nanoparticles in the oxidative dehydrogenation catalyst of the present invention are small in size, which reduces the adsorption of reaction products on the pore surface of the oxidative dehydrogenation catalyst, thereby improving the activity of the oxidative dehydrogenation catalyst under low water ratio conditions;

[0011] The preparation method of the invention adopts the method of adding rare earth metal sulfide and soluble high molecular organic matter in the process of preparing the ferrite coprecipitation of the spinel structure, which can avoid the growth of particles and reduce the size of the spinel and iron oxide nanoparticles in the oxidative dehydrogenation catalyst. DETAILED DESCRIPTION

[0012] 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.

[0013] The present invention provides an oxidative dehydrogenation catalyst, the crystal phase structure of which contains a spinel phase and a gamma-iron oxide phase with a chemical formula of AB2O4, and a group IIIB metal sulfide; the particle sizes of the spinel phase and the gamma-iron oxide phase are respectively 1-100 nanometers.

[0014] The spinel and iron oxide nanoparticles in the oxidative dehydrogenation catalyst of the present invention are small in size, which reduces the adsorption of reaction products on the pore surface of the oxidative dehydrogenation catalyst, thereby improving the activity of the oxidative dehydrogenation catalyst under low water ratio conditions.

[0015] According to a preferred embodiment of the present invention, the particle sizes of the spinel phase and the γ-iron oxide phase are 1-100 nanometers, preferably 5-100 nanometers. By adopting the above preferred embodiment, the activity of the oxidative dehydrogenation catalyst under low water ratio conditions can be further improved.

[0016] According to a preferred embodiment of the present invention, the particle size of the spinel phase is 5-60 nanometers. By adopting the above preferred embodiment, the activity of the oxidative dehydrogenation catalyst under low water ratio conditions can be further improved.

[0017] According to a preferred embodiment of the present invention, the particle size of the γ-iron oxide phase is 20-90 nanometers. By adopting the above preferred embodiment, the activity of the oxidative dehydrogenation catalyst under low water ratio conditions can be further improved.

[0018] According to a preferred embodiment of the present invention, the pore volume of the oxidative dehydrogenation catalyst is 1.0-10.0 ml / g, preferably 3.0-8.0 ml / g. By adopting the above preferred embodiment, the activity of the oxidative dehydrogenation catalyst under low water ratio conditions can be further improved.

[0019] According to a preferred embodiment of the present invention, the average pore size of the oxidative dehydrogenation catalyst is 30-70 nanometers, preferably 35-60 nanometers. By adopting the above preferred embodiment, the activity of the oxidative dehydrogenation catalyst under low water ratio conditions can be further improved.

[0020] According to a preferred embodiment of the present invention, the specific surface area of ​​the oxidative dehydrogenation catalyst is 1-90 m 2 / g, preferably 15-80m 2 By adopting the above preferred embodiment, the activity of the oxidative dehydrogenation catalyst under low water ratio conditions can be further improved.

[0021] According to a preferred embodiment of the present invention, in the spinel phase having the chemical formula AB2O4, A 2+ Selected from Ca 2+ , Mn 2+ 、Co 2+ 、Ni 2+ , Cu 2+ 、Zn 2+ 、Cd 2+ , Hg 2+ , Sr 2+ Mg 2+ Sn 2+ At least one of .

[0022] According to a preferred embodiment of the present invention, in the spinel phase having the chemical formula AB2O4, B 3+ Selected from Fe 3+ , and / or Al 3+ 、Co 3+ 、Bi 3+ 、Ti 3+ 、V 3+ 、In 3+ At least one of the following, which may be Fe3+ With Al 3+ 、Co 3+ 、Bi 3+ 、Ti 3+ 、V 3+ 、In 3+ A combination of at least one of .

[0023] According to a preferred embodiment of the present invention, the IIIB group metal is selected from at least one of yttrium, scandium, and lanthanide metal elements, preferably at least one of yttrium, scandium, lanthanum, cerium, and praseodymium sulfide, for example, it can be at least one of yttrium sulfide, cerium sulfide, lanthanum calcium sulfide, scandium sulfide, lanthanum strontium sulfide, and praseodymium sulfide. By adopting the above preferred embodiment, the activity of the oxidative dehydrogenation catalyst under low water ratio conditions can be further improved.

[0024] According to a preferred embodiment of the present invention, in the crystal phase structure of the oxidative dehydrogenation catalyst, the content of the spinel phase is 20-40wt%, preferably 22-38%; the content of the γ-iron oxide phase is 60-80wt%, preferably 62-78%. By adopting the above preferred scheme, the activity of the oxidative dehydrogenation catalyst under low water ratio conditions can be further improved.

[0025] According to a preferred embodiment of the present invention, the content of Group IIIB metal sulfide in the oxidative dehydrogenation catalyst is 1.0-10.0 wt%, preferably 1.5-8.0 wt%. By adopting the above preferred solution, the activity of the oxidative dehydrogenation catalyst under low water ratio conditions can be further improved.

[0026] The present invention provides a method for preparing the oxidative dehydrogenation catalyst, which comprises: mixing a source A, a source B and a preferred first macromolecular organic matter in a solvent, adding an inorganic base, a group IIIB metal sulfide and a second macromolecular organic matter for coprecipitation, solid-liquid separation, washing, drying and roasting.

[0027] The preparation method of the present invention adopts the method of adding rare earth metal sulfide and soluble high molecular organic matter in the process of preparing ferrite coprecipitation with spinel structure, which can avoid particle growth and reduce the size of spinel and iron oxide nanoparticles in the catalyst.

[0028] According to a preferred embodiment of the present invention, the first high molecular organic substance is at least one of polyethylene glycol, starch, sodium methyl cellulose and sucrose. By adopting the above preferred embodiment, the activity of the oxidative dehydrogenation catalyst under low water ratio conditions can be further improved.

[0029] According to a preferred embodiment of the present invention, the second organic macromolecular substance is a water-soluble organic macromolecular substance, preferably at least one of polyacrylic acid, polymethacrylic acid, polyethyleneimine, and polyacrylamide. By adopting the above preferred embodiment, the activity of the oxidative dehydrogenation catalyst under low water ratio conditions can be further improved.

[0030] According to a preferred embodiment of the present invention, the weight average molecular weight of the second high molecular organic matter is 500-20000, more preferably 1000-12000. By adopting the above preferred embodiment, the activity of the oxidative dehydrogenation catalyst under low water ratio conditions can be further improved.

[0031] According to a preferred embodiment of the present invention, the first high molecular organic matter is first configured into a solution and then mixed with source A and source B in a solvent.

[0032] According to a preferred embodiment of the present invention, the inorganic base is selected from at least one of ammonia water, alkali metal hydroxide and alkaline earth metal hydroxide, and the concentration of the inorganic base is adjusted according to demand.

[0033] According to a preferred embodiment of the present invention, the second high molecular organic matter is first configured into a solution and then added into the coprecipitation system.

[0034] According to a preferred embodiment of the present invention, the average particle size of the IIIB group metal sulfide is ≤1 μm, and is added to the coprecipitation system together with a solution containing a second high molecular organic compound.

[0035] In the present invention, any solvent that can dissolve the raw materials of the present invention can be used as the solvent of the present invention, and water is preferred.

[0036] In the present invention, the mixing temperature and other conditions can be conventionally selected in the art, as long as the raw materials can be dissolved.

[0037] According to a preferred embodiment of the present invention, in the preparation method, the feeding amount of the first high molecular organic matter is 0.1-6.0wt% of the total feeding amount excluding the solvent and the inorganic base, preferably 0.6-4.0wt%; the feeding amount of the second high molecular organic matter is 1.0-20wt% of the total feeding amount excluding the solvent and the inorganic base, preferably 5.0-18.0wt%.

[0038] According to a preferred embodiment of the present invention, the co-precipitation conditions include: temperature of 10-50° C.; pH of 8.0-11.0.

[0039] According to a preferred embodiment of the present invention, the calcination conditions include: a calcination temperature of 500-750° C., preferably 620-700° C., and a calcination time of 4-18 hours.

[0040] In the present invention, the solid-liquid separation, washing and drying methods can be conventional choices in the field. For example, solid-liquid separation can be filtration, suction filtration, etc., washing can be, for example, pulping and washing with deionized water at least once, and drying can be, for example, carried out at 110°C.

[0041] The present invention provides an application of the oxidative dehydrogenation catalyst in the preparation of an oxidative dehydrogenation catalyst, preferably an application of the oxidative dehydrogenation catalyst in the preparation of a catalyst for producing butadiene by oxidative dehydrogenation of butene.

[0042] The catalyst prepared by the oxidative dehydrogenation catalyst of the present invention is used for oxidative dehydrogenation of butene to prepare butadiene, and has high butadiene selectivity.

[0043] The present invention provides a method for preparing butadiene by oxidative dehydrogenation of butene, wherein the method uses a butene-containing material as a raw material, water as a diluent, and molecular oxygen as an oxidant, and the reaction temperature is 280-600°C, the reaction pressure is 0-0.4MPa, and the butene volume space velocity is 100-500h -1 , the volume ratio of H2O / butene is 3-6, the volume ratio of O2 / butene is 0.4-1.0, and the catalyst containing the oxidative dehydrogenation catalyst is contacted to react to produce butadiene.

[0044] The present invention will be described in detail below through examples.

[0045] In the following examples, the average pore size, pore volume and specific surface area parameters are measured by nitrogen physical adsorption; the crystal phase composition parameters are tested by X-ray diffraction method; the particle size is measured by laser particle size analyzer; product selection and raw material conversion rate are obtained by gas chromatography quantitative detection of raw materials and products, and the by-product content is calculated; unless otherwise specified, the raw materials are commercially available.

[0046] Example 1

[0047] 84.4 g of polyacrylic acid (molecular weight 4000) was dissolved in 300 ml of water to form an aqueous solution; 637.8 g of ferric nitrate (Fe(NO3)3 9H2O), 121.8 g of zinc nitrate (Zn(NO3)2.6H2O) and 15.3 g of sodium methylcellulose (weight average molecular weight 10000) were added to 1200 ml of deionized water, and then co-precipitated at room temperature (25°C, the same below) with 20 wt% ammonia water to control the pH of the system to 9.2. At the same time, during the co-precipitation process, the polyacrylic acid solution and 7.5 g of yttrium sulfide (Y2S3; average particle size <1 μm) powder were uniformly sprayed into the precipitated slurry. The precipitated slurry was filtered, washed four times with 800 ml of deionized water, dried at 110°C and calcined at 680°C for 8 hours to obtain catalyst A.

[0048] The crystal phase composition, particle size, pore volume, specific surface area and other parameters of the obtained samples as well as the reaction temperature of 320-600℃, reaction pressure of 0.1MPa and butene volume space velocity of 400h -1 , H2O / butene volume ratio of 5, O2 / butene volume ratio of 0.4-1.0, the catalyst performance after reaction for 50 hours and 200 hours is shown in Table 1.

[0049] Example 2

[0050] 62.0 g of polyacrylamide (molecular weight 7000) was dissolved in 300 ml of water to form aqueous solution 1; 8.5 g of starch was added to 50 ml of deionized water, heated to 100° C. to form a transparent slurry, and then cooled to obtain solution 2; 657.0 g of ferric nitrate (Fe(NO3)39H2O) and 104.4 g of magnesium nitrate (Mg(NO3)2.6H2O) were taken in 1200 ml of deionized water, and solution 2 was added and mixed evenly. Then, at room temperature, 20 wt % of ammonia water was used to control the pH of the system to 9.2 for co-precipitation. At the same time, during the co-precipitation process, the polyacrylamide solution and 6.0 g of lanthanum strontium sulfide powder (average particle size <1 μm) were uniformly sprayed into the precipitated slurry. The precipitated slurry was filtered, washed 4 times with 800 ml of deionized water, dried at 110° C. and calcined at 680° C. for 8 hours to obtain catalyst B.

[0051] The crystal phase composition, particle size, pore volume, specific surface area and other parameters of the obtained samples as well as the reaction temperature of 320-600℃, reaction pressure of 0.1MPa and butene volume space velocity of 400h -1 , H2O / butene volume ratio of 5, O2 / butene volume ratio of 0.4-1.0, the catalyst performance after reaction for 50 hours and 200 hours is shown in Table 1.

[0052] Example 3

[0053] 117.7g of polymethacrylic acid (molecular weight 8000) is dissolved in 300ml of water to form an aqueous solution; 641.2g of ferric nitrate (Fe(NO3)3 9H2O), 139.2g of cobalt nitrate (Co(NO3)2.6H2O) and 25.1g of polyethylene glycol (weight average molecular weight 8000) are taken in 1200ml of deionized water, and then at room temperature, 18wt% of ammonia water is used to control the pH of the system to 8.9 for co-precipitation. At the same time, during the co-precipitation process, the polymethacrylic acid solution and 4.5g of scandium sulfide (Sc2S3 average particle size <1μm) powder are evenly sprayed into the precipitation slurry. The precipitated slurry is filtered and washed 4 times with 800ml of deionized water, dried at 110°C and calcined at 680°C for 8 hours to obtain catalyst C.

[0054] The crystal phase composition, particle size, pore volume, specific surface area and other parameters of the obtained samples as well as the reaction temperature of 320-600℃, reaction pressure of 0.1MPa and butene volume space velocity of 400h -1 , H2O / butene volume ratio of 5, O2 / butene volume ratio of 0.4-1.0, the catalyst performance after reaction for 50 hours and 200 hours is shown in Table 1.

[0055] Example 4

[0056] 84.4 g of polyacrylic acid (molecular weight 4000) was dissolved in 300 ml of water to form an aqueous solution; 637.8 g of ferric nitrate (Fe(NO3)3 9H2O) and 121.8 g of zinc nitrate (Zn(NO3)2.6H2O) were dissolved in 1200 ml of deionized water, and then co-precipitated at room temperature using 20 wt% ammonia water to control the pH of the system to 8.2. During the co-precipitation process, the polyacrylic acid solution and 7.5 g of yttrium sulfide (Y2S3; average particle size <1 μm) powder were evenly sprayed into the precipitated slurry. The precipitated slurry was filtered, washed four times with 800 ml of deionized water, dried at 110°C and calcined at 680°C for 8 hours to obtain catalyst D.

[0057] The crystal phase composition, particle size, pore volume, specific surface area and other parameters of the obtained samples as well as the reaction temperature of 320-600℃, reaction pressure of 0.1MPa and butene volume space velocity of 400h -1 , H2O / butene volume ratio of 5, O2 / butene volume ratio of 0.4-1.0, the catalyst performance after reaction for 50 hours and 200 hours is shown in Table 1.

[0058] Example 5

[0059] 84.4 g of polyacrylic acid (molecular weight 600) was dissolved in 300 ml of water to form an aqueous solution; 637.8 g of ferric nitrate (Fe(NO3)3 9H2O), 121.8 g of zinc nitrate (Zn(NO3)2.6H2O) and 15.3 g of sodium methylcellulose (weight average molecular weight 10000) were added to 1200 ml of deionized water, and then co-precipitated at room temperature using 20 wt % ammonia water to control the pH of the system to 10.6. During the co-precipitation process, the polyacrylic acid solution and 7.5 g of yttrium sulfide (Y2S3; average particle size <1 μm) powder were uniformly sprayed into the precipitated slurry. The precipitated slurry was filtered, washed four times with 800 ml of deionized water, dried at 110° C. and calcined at 680° C. for 8 hours to obtain catalyst E.

[0060] The crystal phase composition, particle size, pore volume, specific surface area and other parameters of the obtained samples as well as the reaction temperature of 320-600℃, reaction pressure of 0.1MPa and butene volume space velocity of 400h -1, H2O / butene volume ratio of 5, O2 / butene volume ratio of 0.4-1.0, the catalyst performance after reaction for 50 hours and 200 hours is shown in Table 1.

[0061] Example 6

[0062] 84.4 g of polyacrylic acid (molecular weight 4000) is dissolved in 300 ml of water to form an aqueous solution; 637.8 g of ferric nitrate (Fe(NO3)3 9H2O), 121.8 g of zinc nitrate (Zn(NO3)2.6H2O) and 15.3 g of sodium methyl cellulose (weight average molecular weight 10000) are taken in 1200 ml of deionized water, and then at room temperature, 22 wt% of ammonia water is used to control the pH of the system to 9.5 for co-precipitation. At the same time, during the co-precipitation process, the polyacrylic acid solution and 7.5 g of thulium sulfide (Tm2S3; average particle size <1 μm) powder are uniformly sprayed into the precipitation slurry. The precipitated slurry is filtered and washed 4 times with 800 ml of deionized water, dried at 110°C and calcined at 680°C for 8 hours to obtain a composite oxide catalyst F.

[0063] The crystal phase composition, particle size, pore volume, specific surface area and other parameters of the obtained samples as well as the reaction temperature of 320-600℃, reaction pressure of 0.1MPa and butene volume space velocity of 400h -1 , H2O / butene volume ratio of 5, O2 / butene volume ratio of 0.4-1.0, the catalyst performance after reaction for 50 hours and 200 hours is shown in Table 1.

[0064] Comparative Example 1

[0065] The catalyst was prepared according to the method of Example 1, except that no polyacrylic acid was added.

[0066] The crystal phase composition, particle size, pore volume, specific surface area and other parameters of the obtained samples as well as the reaction temperature of 320-600℃, reaction pressure of 0.1MPa and butene volume space velocity of 400h -1 , H2O / butene volume ratio of 5, O2 / butene volume ratio of 0.4-1.0, the catalyst performance after reaction for 50 hours and 200 hours is shown in Table 1.

[0067] Comparative Example 2

[0068] The catalyst was prepared according to the method of Example 1, except that polyacrylic acid and yttrium sulfide were not added.

[0069] The crystal phase composition, particle size, pore volume, specific surface area and other parameters of the obtained samples as well as the reaction temperature of 320-600℃, reaction pressure of 0.1MPa and butene volume space velocity of 400h -1, H2O / butene volume ratio of 5, O2 / butene volume ratio of 0.4-1.0, the catalyst performance after reaction for 50 hours and 200 hours is shown in Table 1.

[0070] Comparative Example 3

[0071] The catalyst was prepared according to the method of Example 1, except that yttrium sulfide was not added.

[0072] The crystal phase composition, particle size, pore volume, specific surface area and other parameters of the obtained samples as well as the reaction temperature of 320-600℃, reaction pressure of 0.1MPa and butene volume space velocity of 400h -1 , H2O / butene volume ratio of 5, O2 / butene volume ratio of 0.4-1.0, the catalyst performance after reaction for 50 hours and 200 hours is shown in Table 1.

[0073]

[0074]

[0075] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. An oxidative dehydrogenation catalyst, characterized in that The oxidative dehydrogenation catalyst has a crystal phase structure containing a spinel phase and a gamma-iron oxide phase with a chemical formula of AB2O4, and a group IIIB metal sulfide; The particle sizes of the spinel phase and the gamma-iron oxide phase are each 1 to 100 nanometers.

2. The oxidative dehydrogenation catalyst according to claim 1, wherein The particle sizes of the spinel phase and the γ-iron oxide phase are each 1-100 nanometers; preferably, The spinel phase has a particle size of 5-60 nanometers; and / or The particle size of the gamma-iron oxide phase is 20-90 nanometers.

3. The oxidative dehydrogenation catalyst according to claim 1 or 2, wherein The pore volume of the oxidative dehydrogenation catalyst is 1.0-10.0 ml / g, preferably 3.0-8.0 ml / g; and / or The average pore size of the oxidative dehydrogenation catalyst is 30-70 nanometers, preferably 35-60 nanometers; and / or The specific surface area of ​​the oxidative dehydrogenation catalyst is 1-90 m 2 / g, preferably 15-80m 2 / g.

4. The oxidative dehydrogenation catalyst according to any one of claims 1 to 3, wherein In the spinel phase with the chemical formula AB2O4, A 2+ Selected from Ca 2+ , Mn 2+ 、Co 2+ 、Ni 2+ , Cu 2+ 、Zn 2+ 、Cd 2+ , Hg 2+ , Sr 2+ Mg 2+ Sn 2+ At least one of; and / or B 3+ Selected from Fe 3+ , and / or Al 3+ 、Co 3+ 、Bi 3+ 、Ti 3+ 、V 3+ 、In 3+ At least one of .

5. The oxidative dehydrogenation catalyst according to any one of claims 1 to 4, wherein The IIIB group metal is selected from at least one of yttrium, scandium and lanthanide metal elements, preferably at least one of yttrium, scandium, lanthanum, cerium and praseodymium.

6. The oxidative dehydrogenation catalyst according to any one of claims 1 to 5, wherein In the crystal phase structure of the oxidative dehydrogenation catalyst, the content of the spinel phase is 20-40 wt%, and the content of the γ-iron oxide phase is 60-80 wt%; and / or The content of Group IIIB metal sulfide in the oxidative dehydrogenation catalyst is 1.0-10.0 wt%, preferably 1.5-8.0 wt%.

7. The method for preparing the oxidative dehydrogenation catalyst according to any one of claims 1 to 6, characterized in that: The preparation method comprises: mixing source A, source B and a preferred first macromolecular organic matter in a solvent, adding an inorganic base, group IIIB metal sulfide and a second macromolecular organic matter for coprecipitation, solid-liquid separation, washing, drying and roasting.

8. The preparation method according to claim 7, wherein: The first high molecular organic substance is at least one of polyethylene glycol, starch, sodium methyl cellulose and sucrose; and / or The second high molecular organic substance is at least one of polyacrylic acid, polymethacrylic acid, polyethyleneimine and polyacrylamide. Preferably, The weight average molecular weight of the second high molecular organic substance is 500-20000, more preferably 1000-12000.

9. The preparation method according to claim 7 or 8, wherein: The feeding amount of the first high molecular weight organic matter is 0.1-6.0wt% of the total feeding amount excluding the solvent and the inorganic base, preferably 0.6-4.0wt%; and / or The feeding amount of the second high molecular weight organic matter is 1.0-20wt% of the total feeding amount excluding the solvent and the inorganic base, preferably 5.0-18.0wt%; and / or The coprecipitation conditions include: temperature of 10-50°C; pH of 8.0-11.0; and / or The calcination conditions include: calcination temperature of 500-750° C., preferably 620-700° C.; and calcination time of 4-18 hours.

10. Use of the oxidative dehydrogenation catalyst according to any one of claims 1 to 6 in the preparation of a catalyst for oxidative dehydrogenation of butene to butadiene.

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