A catalyst for preparing dianhydride by gas phase oxidation of durene, a preparation method thereof and a method for producing dianhydride

Abstract

The present application provides a catalyst for preparing dianhydride from gas phase oxidation of durene, a preparation method of the catalyst and a method for producing dianhydride, wherein the catalyst comprises an inert carrier and an active component; the inert carrier is zinc oxide nanorod. The catalyst effectively improves the binding force between the coating of the active component and the inert carrier, effectively reduces the catalyst abrasion and the loss of the active component caused by the coating falling off, and is beneficial to improving the selectivity and mechanical stability of the catalyst.

Description

Technical Field

[0001] This invention relates to the field of catalysis technology, specifically to a catalyst for the gas-phase oxidation of mesitylene to produce homogeneous anhydride, a method for preparing the catalyst, and a method for producing homogeneous anhydride. Background Technology

[0002] With the development of the petroleum refining industry, large-scale ethylene plants, catalytic reforming units, and aromatics plants will produce large quantities of C10 aromatics as byproducts. How to efficiently and economically utilize C10 aromatic resources has become one of the important research directions in petrochemicals. Mesitylene in C10 aromatics can be used to produce pyromellitic dianhydride (PMDA). Pyromellitic dianhydride is a high-value-added fine chemical intermediate with excellent heat resistance, chemical resistance, and dielectric properties. It can be used to produce monomers for heat-resistant resins such as polyimide and polyimide, pharmaceutical intermediates, and crosslinking agents for high-end resin materials. Its related products are widely used in high-tech industries such as aerospace, 5G communications, and flexible displays. Therefore, separating mesitylene from C10 aromatics to prepare pyromellitic dianhydride is an effective way to utilize C10 aromatic resources, which has significant research importance and substantial economic value. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a catalyst with zinc oxide nanowires having a one-dimensional structure as an inert support for homogenizing anhydride catalysts.

[0004] Currently, the main method for preparing homohydric anhydride from mesitylene is the gas-phase oxidation method, which relies on a fixed-bed reactor. The advantages of this method are that it directly generates homohydric anhydride in a single reaction, high atom utilization efficiency, and a green and environmentally friendly production process. The disadvantages are numerous side reactions, low homohydric anhydride yield, and short catalyst lifetime. The catalysts used in the gas-phase oxidation method mainly consist of vanadium oxide and titanium oxide, which are prepared as a slurry and sprayed onto an inert support.

[0005] Existing research indicates that the choice of different inert supports affects reaction performance. In an earlier study (Journal of Shenyang Institute of Technology, 1998, 03, 35-39), researchers compared the activities of catalysts prepared using four inert supports—α-Al₂O₃, ceramic spheres, α-SiC, and β-SiC—at a specific reaction temperature. The results showed that the crystal structure of α-SiC was more suitable for the inert support requirements of this reaction. However, due to the high cost of silicon carbide, ceramic spheres are currently the primary support choice in industrial applications. One drawback of existing catalysts is their poor mechanical stability, leading to easy coating peeling and affecting catalyst lifespan. Therefore, finding an inert support with excellent support properties and preparing catalysts with high coating strength is urgently needed.

[0006] Zinc oxide nanomaterials have become one of the most promising materials in the field of nanotechnology due to their immense potential for success in chemistry, electronics, and optics. The unique surface effects of nanomaterials enable them to exhibit superior properties in catalysis compared to traditional materials. However, the developed surface effects also make nanoparticles more prone to aggregation. Therefore, effectively dispersing nanoparticles is an issue that cannot be ignored in the design of nanomaterials. This invention is the first to discover that one-dimensional zinc oxide nanowires with a high aspect ratio, used as an inert support, exhibit excellent performance in the synthesis of homohydric anhydride. Compared to catalysts using alumina, silicon carbide, and ceramic spheres as inert supports, the catalyst described in this invention possesses high mechanical stability and high yield.

[0007] It is speculated that one-dimensional zinc oxide nanorods, due to their high aspect ratio, possess the ability to retain the small size effect of nanoparticles radially (nanometer-scale diameter) and introduce the macroscopic properties of bulk materials vertically (micrometer-scale length). This effectively reduces the surface energy of nanomaterials, preventing aggregation and sintering during use, and exhibiting excellent mechanical stability. Simultaneously, the unique one-dimensional structure of zinc oxide nanorods at a small scale enables good adhesion between the active component coating and the support, enhancing the bonding force and improving the mechanical stability of the catalyst. Furthermore, their low surface energy prevents the aggregation of active components, promoting their uniform distribution.

[0008] To achieve the aforementioned objective, according to a first aspect of the present invention, the present invention provides a catalyst for the gas-phase oxidation of mesitylene to homohydric anhydride, the catalyst comprising an inert support and an active component; the inert support being zinc oxide nanorods.

[0009] According to a second aspect of the present invention, the present invention provides a method for preparing the catalyst described above, the method comprising:

[0010] (a) Obtaining zinc oxide nanorods to serve as inert supports;

[0011] (b) Obtaining a precursor slurry containing the catalyst active component;

[0012] (c) The precursor slurry is sprayed onto zinc oxide nanorods by a spraying method, and then calcined to obtain the catalyst.

[0013] According to a third aspect of the present invention, a method for producing homogeneous anhydride is provided, employing a fixed-bed reactor, wherein the feedstock mesitylene and an oxygen-containing gas are contacted in the presence of the catalyst described herein, wherein the contact conditions include: a mesitylene mass concentration of 10-40 g / cm³. 3 The gas hourly space velocity is 4000-8000 hr. -1 The reaction temperature is 350-500℃ and the reaction pressure is atmospheric pressure.

[0014] Compared with the prior art, the catalyst of the present invention uses one-dimensional zinc oxide nanorods with high aspect ratio as an inert support, which can bind the coating and exert an excellent support effect, effectively improving the mechanical stability and yield of the catalyst.

[0015] When the catalyst described in this invention is used for the gas-phase oxidation of mesitylene to produce homohydric anhydride, good technical results have been achieved.

[0016] The catalyst of this invention effectively improves the bonding force between the active component coating and the inert support, effectively reduces catalyst wear and loss of active components caused by coating peeling, and is beneficial to improving the selectivity and mechanical stability of the catalyst. Attached Figure Description

[0017] Figure 1 This is a SEM image of the zinc oxide nanowires synthesized in Preparation Example 1.

[0018] Figure 2 This is the XRD pattern of the zinc oxide nanorods synthesized in Preparation Example 1. Detailed Implementation

[0019] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0020] This invention provides a catalyst for the gas-phase oxidation of mesitylene to homohydric anhydride, the catalyst comprising an inert support and an active component; the inert support is zinc oxide nanorods. The catalyst, using one-dimensional zinc oxide nanowires with a high aspect ratio as an inert support, exhibits excellent performance in the synthesis of homohydric anhydride. Compared to catalysts using alumina, silicon carbide, and ceramic spheres as inert supports, the catalyst of this invention possesses high mechanical stability and high yield.

[0021] According to a preferred embodiment of the present invention, the aspect ratio of the zinc oxide nanorods is 40-130, for example 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, preferably 42-55. This can further improve the mechanical stability and yield of the catalyst.

[0022] According to a preferred embodiment of the present invention, the length of the zinc oxide nanorods is 3.0-3.9 μm, for example, 3.5-3.9 μm, 3.2-3.7 μm, or 3.0-3.5 μm. This can further improve the mechanical stability and yield of the catalyst.

[0023] According to a preferred embodiment of the present invention, the zinc oxide nanorods have a diameter of 30-70 nm, for example, 30-50 nm, 40-60 nm, or 40-70 nm. This can further improve the mechanical stability and yield of the catalyst.

[0024] According to a preferred embodiment of the present invention, the zinc oxide nanorods have a hexagonal zinc oxide crystal phase. This can further improve the mechanical stability and yield of the catalyst.

[0025] In this invention, the content range of inert support and active component can be selected in a wide range. This is an illustrative example, but it does not limit the scope of the invention. Based on the total weight of the catalyst, the content of support is 60-97 wt%.

[0026] In this invention, the active component is based on the total weight of the catalyst and is calculated by the weight of its corresponding oxide. The content of the active component is 1-50 wt%, preferably 3-40 wt%. In the examples, 10 wt% is used as an example to illustrate the advantages of this invention.

[0027] In this invention, there are no special requirements for the active components. The following is an illustrative description but does not limit the scope of the invention. According to one embodiment of the invention, the active components of the catalyst include a main active component oxide and a co-active component element oxide. The main active component oxide includes vanadium oxide and titanium oxide.

[0028] According to a preferred embodiment of the present invention, the auxiliary active component element is selected from at least one of the transition metal elements and non-metal elements.

[0029] According to a preferred embodiment of the present invention, preferably, the mass ratio of the vanadium oxide, titanium oxide, and co-activating component element oxide is (0.005-0.5):1:(0.003-0.28). This can further improve the catalyst yield.

[0030] According to a preferred embodiment of the present invention, the transition metal element preferably includes one or more of zirconium, niobium, and tungsten; thereby, the yield of the target substance of the catalyst can be further improved.

[0031] According to a preferred embodiment of the present invention, the non-metallic element includes one or more of phosphorus and boron; thereby, the yield of the target substance of the catalyst can be further improved.

[0032] In this invention, the mass ratio of vanadium oxide, titanium oxide, transition metal oxide, and non-metal oxide can be selected within a wide range, for example, a mass ratio of (0.005-0.5):1:(0.0001-0.2):(0.001-0.08). This can further improve the yield of the target product of the catalyst.

[0033] According to a preferred embodiment of the present invention, the mass ratio of vanadium oxide, titanium oxide, transition metal oxide, and non-metal oxide is preferably (0.05-0.45):1:(0.0005-0.002):(0.002-0.05). This can further improve the yield of the target product of the catalyst.

[0034] According to a preferred embodiment of the present invention, the co-activating component preferably includes niobium oxide, tungsten oxide, and phosphorus oxide; preferably, the mass ratio of the three is 0.01-1:0.01-1:1. This can further improve the yield of the target substance in the catalyst.

[0035] The present invention does not have any special requirements for the preparation method of the inert carrier. Any inert carrier that meets the aforementioned characteristics can achieve the purpose of the present invention. For the present invention, the preferred preparation method of the inert carrier includes the following steps: (1) obtaining a mixed solution including zinc source, polyethylene glycol, water, ethanol and sodium hydroxide;

[0036] (2) Transfer the mixed solution to a hydrothermal reactor for hydrothermal reaction;

[0037] (3) After the hydrothermal reaction is complete, the reaction product is washed, filtered, dried, calcined and optionally shaped.

[0038] In step (1), the mass ratio of water to ethanol is 0-2:1 (0 means infinitely close to 0 but not 0), preferably 0.005-0.5:1, and more preferably 0.01-0.4, for example 0.05, 0.25, or 0.4. It is speculated that the dielectric constant of the solution can be controlled through the aforementioned technical solution, and the inert carrier described in this invention can be prepared.

[0039] The present invention does not have any special requirements for the hydrothermal reactor, such as a stainless steel hydrothermal reactor with a polyethylene tetroxide liner.

[0040] In this invention, there are no special requirements for obtaining a mixed solution comprising zinc source, polyethylene glycol, ethanol and sodium hydroxide. For example, it can generally be carried out according to the following steps: weigh zinc source and polyethylene glycol and dissolve them in deionized water. After stirring until completely dissolved, add ethanol to obtain a mixed solution and stir. When white foam is observed in the solution, add NaOH and continue stirring until completely dissolved.

[0041] In this invention, the range of amounts of each substance can be selected from a wide range. The ranges commonly used in the art can be applied to this invention. The following is an illustrative description, but it does not limit the scope of this invention.

[0042] In this invention, the weight ratio of zinc source to ethanol can be selected within a wide range, for example, a weight ratio of 0.001-0.1. In this embodiment, 0.015 is used as an example to illustrate the advantages of this invention. However, this does not limit the scope of the invention.

[0043] In this invention, the weight ratio of polyethylene glycol to ethanol can be selected within a wide range, for example, a weight ratio of 0.001-0.1. In the examples, 0.02 is used as an example to illustrate the advantages of this invention. However, this does not limit the scope of the invention.

[0044] In this invention, the weight ratio of water to ethanol can be selected within a wide range, for example, a weight ratio of 0-2:1 (0 means infinitely close to 0, but not 0), preferably 0.005-0.5:1, preferably 0.01-0.4, for example 0.05, 0.25, 0.4. However, this does not limit the scope of this invention.

[0045] In this invention, the weight ratio of sodium hydroxide to ethanol can be selected within a wide range, for example, 0.01-0.1. In the examples, 0.03 is used as an example to illustrate the advantages of this invention. However, this does not limit the scope of the invention.

[0046] According to a preferred embodiment of the present invention, preferably, the weight ratio of zinc source, polyethylene glycol, water, ethanol and sodium hydroxide is 0.001-0.1:0.001-0.1:0.005-0.5:1:0.01-0.1.

[0047] According to a preferred embodiment of the present invention, preferably, in step (1), the polyethylene glycol is one or more of polyethylene glycol 2000, polyethylene glycol 10000, and polyethylene glycol 20000, preferably polyethylene glycol 20000. Using the aforementioned preferred molecular weight polyethylene glycol enables it to react with Zn in solution. 2+ The strong interaction is beneficial to the directional growth of ZnO crystals.

[0048] In this invention, there are no special requirements for the zinc source. This is an illustrative description but does not limit the scope of the invention. Preferably, in step (1), the zinc source is one or more of zinc acetate, zinc sulfate, and zinc nitrate, with zinc acetate being preferred.

[0049] In this invention, the range of selectable hydrothermal reaction conditions is relatively wide. For this invention, the hydrothermal reaction conditions in step (2) preferably include: a reaction temperature of 80-200℃, preferably 100-150℃, such as 100℃, 120℃, 140℃, 150℃, etc.

[0050] In this invention, the range of selectable hydrothermal reaction conditions is relatively wide, and the hydrothermal reaction time can be determined as needed. For example, the general reaction time is 8-24h, preferably 10-18h, such as 10h, 12h, 14h, 16h, and 18h.

[0051] The present invention has no special requirements for washing, nor for the type of detergent. In the present invention, in step (3), the detergent is one or more of water, methanol and ethanol. Preferably, the detergent is water and / or ethanol. Usually, water and ethanol are used to wash multiple times, generally more than 3 times each.

[0052] In this invention, there are no special requirements for the drying, roasting, and molding methods. The following is an illustrative description, but it does not limit the scope of this invention.

[0053] For example, the drying temperature is 40-100℃, preferably 60-80℃; the drying time is, for example, 4-8 hours.

[0054] For example, the roasting temperature is 300-600℃, preferably 400-500℃, and the roasting time is, for example, 3-6 hours.

[0055] For example, the forming method is extrusion and / or tableting.

[0056] This invention does not impose any special requirements on the preparation method of the catalyst. For this invention, a preferred preparation method of the catalyst includes:

[0057] (a) Obtaining zinc oxide nanorods to serve as inert supports;

[0058] (b) Obtaining a precursor slurry containing the catalyst active component;

[0059] (c) The precursor slurry is sprayed onto zinc oxide nanorods by a spraying method, and then calcined to obtain the catalyst.

[0060] This invention does not have any special requirements for the types of raw materials used in the preparation of the catalyst. The following is an illustrative description, but it does not limit the scope of the invention.

[0061] For example, the active components of the catalyst include a main active component oxide and a co-active component element oxide, wherein the main active component oxide includes vanadium oxide and titanium oxide; and the co-active component element is selected from at least one of the transition metal elements and non-metal elements.

[0062] For example, the vanadium source can be one or more of metavanadate, vanadium oxide, and orthovanadate.

[0063] For example, the titanium source can be one or more of titanates, titanium oxides, and titanium halides.

[0064] For example, the preferred active component element is one or more of zirconium, niobium, tungsten, phosphorus and boron; the zirconium source is, for example, at least one of zirconium oxide and zirconium silicate.

[0065] For example, the niobium source can be at least one of niobium oxalate and niobium pentachloride.

[0066] For example, the tungsten source can be at least one of tungstic acid and ammonium metatungstate.

[0067] For example, the phosphorus source is at least one of phosphoric acid and ammonium dihydrogen phosphate.

[0068] For example, the boron source can be at least one of boric acid and ammonium pentaborate.

[0069] In this invention, there are no special requirements for spraying and baking. The description is illustrative but does not limit the scope of the invention. In step (c), for example, the spraying temperature is 60-180℃, preferably 80-160℃, such as 80℃, 100℃, 120℃, 140℃, or 160℃.

[0070] For example, the roasting temperature is 350-500℃, preferably 400-480℃, such as 400℃, 450℃, or 480℃.

[0071] For example, the roasting time is 2-10 hours, preferably 3-6 hours.

[0072] This invention provides a method for producing homogeneous anhydride, employing a fixed-bed reactor. In the presence of the catalyst described herein, the feedstock mesitylene is contacted with an oxygen-containing gas. The contact conditions include a mesitylene mass concentration of 10-40 g / cm³. 3 The gas hourly space velocity is 4000-8000 hr. -1 The reaction temperature is 350-500℃ and the reaction pressure is atmospheric pressure.

[0073] According to a preferred embodiment of the present invention, the contact conditions include: a mesitylene mass concentration of 15-30 g / cm³. 3 The gas hourly space velocity is 4000-6000 hr. -1The reaction temperature is 360-480℃, the reaction pressure is atmospheric pressure, and the oxygen-containing gas is air.

[0074] In this invention, to prepare a uniform slurry, the precursor slurry in step (b) can be continuously heated and stirred during preparation, which is a well-known technique in the art. According to a preferred embodiment of the invention, the slurry temperature is preferably 60-100°C, and more preferably 70-90°C. This can improve the yield of the target catalyst.

[0075] According to a preferred embodiment of the present invention, the stirring time is 4-12 hours, preferably 6-10 hours.

[0076] According to a preferred embodiment of the present invention, the particle size of the catalyst is further 40-60 mesh.

[0077] The present invention will be described in detail below through examples. In the following examples, homogeneous anhydride is synthesized using the gas-phase oxidation method of mesitylene. The mass yield of homogeneous anhydride is calculated as follows:

[0078]

[0079] The mass fraction of anhydride in the solid product was obtained by analyzing the solid product using a Waters Alliance series high-performance liquid chromatography (HPLC) system equipped with a Waters e2695 separation module and a PDA detector. All reagents used in the following examples were commercially available analytical grade products from Sinopharm Chemical Reagent Co., Ltd. The mechanical stability of the catalyst in the following examples was expressed as the attrition rate, which was measured using a KM-4D particle attrition analyzer from Dalian Penghui Technology Development Co., Ltd.

[0080] The following description, with reference to examples, further illustrates the contents of this invention, but is not intended to limit the invention. The scope of protection of this invention is determined by the contents of the claims. Any equivalent technical means substitutions made in accordance with the specification do not depart from the scope of protection of this invention.

[0081] In this embodiment of the invention, the crystal phase structure of zinc oxide was determined by a Rigaku D / max 2500v / pc X-ray diffractometer (Japan); the morphology of zinc oxide was determined by a Hitachi SU8000 electron microscope (Japan).

[0082] Preparation Example 1

[0083] Weigh 3g of zinc acetate and 4g of PEG 20000 and dissolve them in 10g of deionized water. Stir until completely dissolved, then add 200g of ethanol to obtain a mixed solution and stir for 2 hours. When white foam appears in the solution, add 6g of NaOH and continue stirring until completely dissolved, which takes approximately 8 hours. Pour the mixed solution into a high-temperature, high-pressure stainless steel hydrothermal reactor with a polyethylene tetroxide liner. Place the reactor in a 120℃ constant temperature drying oven and react for 12 hours. After the reaction is complete, remove the reactor, cool it to room temperature, remove the liner, discard the supernatant, filter the remaining portion, and wash it three times with deionized water and ethanol, respectively. Dry the resulting powder in a 60℃ constant temperature drying oven for 6 hours, then calcine it in a muffle furnace at 450℃ for 4 hours. After pressing into tablets, the inert catalyst support can be obtained.

[0084] via SEM ( Figure 1 Characterization revealed that its microstructure is rod-shaped, exhibiting a distinct one-dimensional structure with a diameter of approximately 30-50 nm and a length of approximately 3.5-3.9 μm, demonstrating good repeatability and uniformity. XRD analysis further confirmed its properties. Figure 2 Characterization revealed that it has obvious diffraction peaks at 2θ = 31.9°, 34.5°, and 36.3°, and the characteristic peaks are consistent with the standard hexagonal wurtzite zinc oxide standard card (JCPDS, No. 36-1451).

[0085] Preparation Example 2

[0086] Weigh 3g of zinc acetate and 4g of PEG 20000 and dissolve them in 50g of deionized water. Stir until completely dissolved, then add 200g of ethanol to obtain a mixed solution and stir for 2 hours. When white foam appears in the solution, add 6g of NaOH and continue stirring until completely dissolved, which takes approximately 8 hours. Pour the mixed solution into a high-temperature, high-pressure stainless steel hydrothermal reactor with a polyethylene tetroxide liner. Place the reactor in a 120℃ constant temperature drying oven and react for 12 hours. After the reaction is complete, remove the reactor, cool it to room temperature, remove the liner, discard the supernatant, filter the remaining portion, and wash it three times with deionized water and ethanol, respectively. Dry the resulting powder in a 60℃ constant temperature drying oven for 6 hours, then calcine it in a muffle furnace at 450℃ for 4 hours. After pressing into tablets, the inert catalyst support can be obtained.

[0087] The SEM images and XRD patterns are similar to those in the examples, with a diameter of approximately 40-60 nm and a length of approximately 3.2-3.7 μm.

[0088] Preparation Example 3

[0089] Weigh 3g of zinc acetate and 4g of PEG 20000 and dissolve them in 80g of deionized water. Stir until completely dissolved, then add 200g of ethanol to obtain a mixed solution and stir for 2 hours. When white foam appears in the solution, add 6g of NaOH and continue stirring until completely dissolved, which takes approximately 8 hours. Pour the mixed solution into a high-temperature, high-pressure stainless steel hydrothermal reactor with a PTFE liner. Place the reactor in a 100℃ constant-temperature drying oven and react for 12 hours. After the reaction is complete, remove the reactor, cool it to room temperature, remove the liner, discard the supernatant, filter the remaining portion, and wash it three times with deionized water and ethanol, respectively. Dry the resulting powder in a 60℃ constant-temperature drying oven for 6 hours, then calcine it in a muffle furnace at 450℃ for 4 hours. After pressing into tablets, the inert catalyst support can be obtained.

[0090] The SEM images and XRD patterns are similar to those in the examples, with a diameter of approximately 40-70 nm and a length of approximately 3.0-3.5 μm.

[0091] Preparation Example 4

[0092] Weigh 3g of zinc acetate and 4g of PEG 20000 and dissolve them in 200g of deionized water. Stir until completely dissolved, then add 200g of ethanol to obtain a mixed solution and stir for 2 hours. When white foam appears in the solution, add 6g of NaOH and continue stirring until completely dissolved, which takes approximately 8 hours. Pour the mixed solution into a high-temperature, high-pressure stainless steel hydrothermal reactor with a polyethylene tetroxide liner. Place the reactor in a 100℃ constant-temperature drying oven and react for 12 hours. After the reaction is complete, remove the reactor, cool it to room temperature, remove the liner, discard the supernatant, filter the remaining portion, and wash it three times with deionized water and ethanol, respectively. Dry the resulting powder in a 60℃ constant-temperature drying oven for 6 hours, then calcine it in a muffle furnace at 450℃ for 4 hours. After pressing, the inert catalyst support can be obtained. Its diameter is approximately 80-120nm and its length is approximately 1.0-2.0μm.

[0093] Example 1

[0094] A spray-coated catalyst for the production of homogeneous anhydride was prepared. The support was zinc oxide nanowires with a one-dimensional linear structure prepared in Preparation Example 1. The vanadium source was ammonium metavanadate, the titanium source was titanium dioxide, and the co-catalyst components were phosphorus and niobium.

[0095] Weigh 80g of oxalic acid and 300mL of distilled water into a three-necked flask, stir and heat to 80℃ to completely dissolve the oxalic acid and obtain an oxalic acid solution. Slowly add 38g of ammonium metavanadate to the prepared oxalic acid solution, and continue stirring until the oxalic acid and ammonium metavanadate react completely to obtain a vanadium oxalate solution. Add 1.2g of ammonium dihydrogen phosphate and 0.8g of niobium oxalate to the solution. Add 120g of titanium dioxide to the solution, and stir for 6 hours while maintaining the solution temperature at 80℃. Place a certain mass of the zinc oxide nanowire carrier prepared above into a sprayer, and spray the above slurry evenly onto the zinc oxide nanowire carrier at a spraying temperature of 110℃. The amount of active component sprayed is 10wt% based on the total weight of the catalyst. Place the sprayed catalyst in a muffle furnace, calcine at 450℃ for 3 hours, and obtain the catalyst after natural cooling. Using mesitylene and air as raw materials, a fixed-bed reactor was used to prepare homohydric anhydride in the presence of a catalyst; the reaction process and temperature conditions were as follows: the mass concentration of mesitylene was 20 g / cm³. 3 The gas hourly space velocity is 5000 hr. -1 The reaction temperature was 390℃, and the reaction pressure was atmospheric pressure. The yield of homogeneous anhydride was measured to be 83.1 wt%. 10 g of catalyst was placed in a particle abrasion tester to determine the abrasion rate. The parameters of the instrument were: inner diameter of the grinding cylinder... The grinding cylinder is 150mm long, the inner baffle is 150mm long and 18mm high, the grinding cylinder speed is 30r / min, and the grinding time is 10min. The catalyst wear rate was measured to be 0.15%.

[0096] Example 2

[0097] A spray-coated catalyst for the production of homogeneous anhydride was prepared. The support was zinc oxide nanowires with a one-dimensional linear structure prepared in Preparation Example 1. The vanadium source was ammonium metavanadate, the titanium source was titanium dioxide, and the co-catalyst components were boron and niobium.

[0098] Weigh 80g of oxalic acid and 300mL of distilled water into a three-necked flask, stir and heat to 80℃ to completely dissolve the oxalic acid and obtain an oxalic acid solution. Slowly add 38g of ammonium metavanadate to the prepared oxalic acid solution, and continue stirring until the oxalic acid and ammonium metavanadate react completely to obtain a vanadium oxalate solution. Add 0.5g of boric acid and 0.8g of niobium oxalate to the solution. Add 120g of titanium dioxide to the solution, and stir for 6 hours while maintaining the solution temperature at 80℃. Place a certain mass of the zinc oxide nanowire carrier prepared above into a sprayer, and spray the above slurry evenly onto the zinc oxide nanowire carrier at a spraying temperature of 110℃. The amount of active component sprayed is 10wt% based on the total weight of the catalyst. Place the sprayed catalyst in a muffle furnace, calcine at 450℃ for 3 hours, and obtain the catalyst after natural cooling. Using mesitylene and air as raw materials, a fixed-bed reactor was used to prepare homohydric anhydride in the presence of a catalyst; the reaction process and temperature conditions were as follows: the mass concentration of mesitylene was 20 g / cm³. 3 The gas hourly space velocity is 5000 hr. -1 The reaction temperature was 390℃, and the reaction pressure was atmospheric pressure. The yield of homogeneous anhydride was measured to be 83.6 wt%. 10 g of catalyst was placed in a particle abrasion tester to determine the abrasion rate. The parameters of the instrument were: inner diameter of the grinding cylinder... The grinding cylinder is 150mm long, the inner baffle is 150mm long and 18mm high, the grinding cylinder speed is 30r / min, and the grinding time is 10min. The catalyst wear rate was measured to be 0.14%.

[0099] Example 3

[0100] A spray-coated catalyst for the production of homogeneous anhydride was prepared. The support was zinc oxide nanowires with a one-dimensional linear structure prepared in Preparation Example 1. The vanadium source was ammonium metavanadate, the titanium source was titanium dioxide, and the co-catalyst components were phosphorus and tungsten.

[0101] Weigh 80g of oxalic acid and 300mL of distilled water into a three-necked flask, stir and heat to 80℃ to completely dissolve the oxalic acid and obtain an oxalic acid solution. Slowly add 38g of ammonium metavanadate to the prepared oxalic acid solution, and continue stirring until the oxalic acid and ammonium metavanadate react completely to obtain a vanadium oxalate solution. Add 1.2g of ammonium dihydrogen phosphate and 1g of ammonium metatungstate to the solution. Add 120g of titanium dioxide to the solution, control the solution temperature at 80℃ and stir for 6 hours. Take a certain mass of the zinc oxide nanowire carrier prepared above and place it in a sprayer. Spray the above slurry evenly onto the zinc oxide nanowire carrier at a spraying temperature of 110℃. Based on the total weight of the catalyst, the spraying amount of the active component is 10wt%. Place the sprayed catalyst in a muffle furnace and calcine at 450℃ for 3 hours. After natural cooling, the catalyst is obtained. Using mesitylene and air as raw materials, a fixed-bed reactor was used to prepare homohydric anhydride in the presence of a catalyst; the reaction process and temperature conditions were as follows: the mass concentration of mesitylene was 20 g / cm³. 3 The gas hourly space velocity is 5000 hr. -1 The reaction temperature was 390℃, and the reaction pressure was atmospheric pressure. The yield of homogeneous anhydride was measured to be 84.4 wt%. 10 g of catalyst was placed in a particle abrasion tester to determine the abrasion rate. The parameters of the instrument were: inner diameter of the grinding cylinder... The grinding cylinder is 150mm long, the inner baffle is 150mm long and 18mm high, the grinding cylinder speed is 30r / min, and the grinding time is 10min. The catalyst wear rate was measured to be 0.16%.

[0102] Example 4

[0103] A spray-coated catalyst for the production of homogeneous anhydride was prepared. The support was zinc oxide nanowires with a one-dimensional linear structure prepared in Preparation Example 1. The vanadium source was ammonium metavanadate, the titanium source was titanium dioxide, and the co-catalyst components were boron and tungsten.

[0104] Weigh 80g of oxalic acid and 300mL of distilled water into a three-necked flask, stir and heat to 80℃ to completely dissolve the oxalic acid and obtain an oxalic acid solution. Slowly add 38g of ammonium metavanadate to the prepared oxalic acid solution, and continue stirring until the oxalic acid and ammonium metavanadate react completely to obtain a vanadium oxalate solution. Add 0.5g of boric acid and 1g of ammonium metatungstate to the solution. Add 120g of titanium dioxide to the solution, control the solution temperature at 80℃ and stir for 6 hours. Take a certain mass of the zinc oxide nanowire carrier prepared above and place it in a sprayer. Spray the above slurry evenly onto the zinc oxide nanowire carrier at a spraying temperature of 110℃. Based on the total weight of the catalyst, the spraying amount of the active component is 10wt%. Place the sprayed catalyst in a muffle furnace and calcine at 450℃ for 3 hours. After natural cooling, the catalyst is obtained. Using mesitylene and air as raw materials, a fixed-bed reactor was used to prepare homohydric anhydride in the presence of a catalyst; the reaction process and temperature conditions were as follows: the mass concentration of mesitylene was 20 g / cm³. 3 The gas hourly space velocity is 5000 hr. -1 The reaction temperature was 390℃, and the reaction pressure was atmospheric pressure. The yield of homogeneous anhydride was measured to be 83.3 wt%. 10 g of catalyst was placed in a particle abrasion tester to determine the abrasion rate. The parameters of the instrument were: inner diameter of the grinding cylinder... The grinding cylinder is 150mm long, the inner baffle is 150mm long and 18mm high, the grinding cylinder speed is 30r / min, and the grinding time is 10min. The catalyst wear rate was measured to be 0.13%.

[0105] Example 5

[0106] A spray-coated catalyst for the production of homogeneous anhydride was prepared. The support was zinc oxide nanowires with a one-dimensional linear structure prepared in Preparation Example 1. The vanadium source was ammonium metavanadate, the titanium source was titanium dioxide, and the co-catalyst components were phosphorus, niobium, and tungsten.

[0107] Weigh 80g of oxalic acid and 300mL of distilled water into a three-necked flask, stir and heat to 80℃ to completely dissolve the oxalic acid to obtain an oxalic acid solution. Slowly add 38g of ammonium metavanadate to the prepared oxalic acid solution, and continue stirring until the oxalic acid and ammonium metavanadate react completely to obtain a vanadium oxalate solution. Add 1.2g of ammonium dihydrogen phosphate, 0.4g of niobium oxalate, and 0.6g of ammonium metatungstate to the solution. Add 120g of titanium dioxide to the solution, control the solution temperature at 80℃ and stir for 6 hours. Take a certain mass of the zinc oxide nanowire carrier prepared above and place it in a sprayer. Spray the above slurry evenly onto the zinc oxide nanowire carrier at a spraying temperature of 110℃. Based on the total weight of the catalyst, the spraying amount of the active component is 10wt%. Place the sprayed catalyst in a muffle furnace and calcine at 450℃ for 3 hours. After natural cooling, the catalyst is obtained. Using mesitylene and air as raw materials, a fixed-bed reactor was used to prepare homohydric anhydride in the presence of a catalyst; the reaction process and temperature conditions were as follows: the mass concentration of mesitylene was 20 g / cm³. 3 The gas hourly space velocity is 5000 hr. -1 The reaction temperature was 390℃, and the reaction pressure was atmospheric pressure. The yield of homogeneous anhydride was measured to be 85.1 wt%. 10 g of catalyst was placed in a particle abrasion tester to determine the abrasion rate. The parameters of the instrument were: inner diameter of the grinding cylinder... The grinding cylinder is 150mm long, the inner baffle is 150mm long and 18mm high, the grinding cylinder speed is 30r / min, and the grinding time is 10min. The catalyst wear rate was measured to be 0.15%.

[0108] As can be seen from Examples 1-5, when the catalyst uses zinc oxide nanowires with a one-dimensional linear structure as a support and phosphorus, niobium and tungsten are selected as the co-active components, it has a better product yield.

[0109] Example 6

[0110] A spray-molded catalyst for the production of homogeneous anhydride was prepared. The support was zinc oxide nanowires prepared in Preparation Example 2, the vanadium source was ammonium metavanadate, the titanium source was titanium dioxide, and the co-catalyst components were phosphorus, niobium, and tungsten.

[0111] Weigh 80g of oxalic acid and 300mL of distilled water into a three-necked flask, stir and heat to 80℃ to completely dissolve the oxalic acid to obtain an oxalic acid solution. Slowly add 38g of ammonium metavanadate to the prepared oxalic acid solution, and continue stirring until the oxalic acid and ammonium metavanadate react completely to obtain a vanadium oxalate solution. Add 1.2g of ammonium dihydrogen phosphate, 0.4g of niobium oxalate, and 0.6g of ammonium metatungstate to the solution. Add 120g of titanium dioxide to the solution, control the solution temperature at 80℃ and stir for 6 hours. Take a certain mass of the zinc oxide nanowire carrier obtained in Preparation Example 2 above and place it in a sprayer. Spray the above slurry evenly onto the zinc oxide nanowire carrier at a spraying temperature of 110℃. Based on the total weight of the catalyst, the spraying amount of the active component is 10wt%. Place the sprayed catalyst in a muffle furnace and calcine at 450℃ for 3 hours. After natural cooling, the catalyst is obtained. Using mesitylene and air as raw materials, a fixed-bed reactor was used to prepare homohydric anhydride in the presence of a catalyst; the reaction process and temperature conditions were as follows: the mass concentration of mesitylene was 20 g / cm³. 3 The gas hourly space velocity is 5000 hr. -1 The reaction temperature was 390℃, and the reaction pressure was atmospheric pressure. The yield of homogeneous anhydride was measured to be 85.4 wt%. 10 g of catalyst was placed in a particle abrasion tester to determine the abrasion rate. The parameters of the instrument were: inner diameter of the grinding cylinder... The grinding cylinder is 150mm long, the inner baffle is 150mm long and 18mm high, the grinding cylinder speed is 30r / min, and the grinding time is 10min. The catalyst wear rate was measured to be 0.18%.

[0112] Example 7

[0113] A spray-coated catalyst for the production of homogeneous anhydride was prepared. The support was zinc oxide nanowires prepared in Preparation Example 3, the vanadium source was ammonium metavanadate, the titanium source was titanium dioxide, and the co-catalyst components were phosphorus, niobium, and tungsten.

[0114] Weigh 80g of oxalic acid and 300mL of distilled water into a three-necked flask, stir and heat to 80℃ to completely dissolve the oxalic acid to obtain an oxalic acid solution. Slowly add 38g of ammonium metavanadate to the prepared oxalic acid solution, and continue stirring until the oxalic acid and ammonium metavanadate react completely to obtain a vanadium oxalate solution. Add 1.2g of ammonium dihydrogen phosphate, 0.4g of niobium oxalate, and 0.6g of ammonium metatungstate to the solution. Add 120g of titanium dioxide to the solution, control the solution temperature at 80℃ and stir for 6 hours. Take a certain mass of the zinc oxide nanowire carrier obtained in Preparation Example 3 above and place it in a sprayer. Spray the above slurry evenly onto the zinc oxide nanowire carrier at a spraying temperature of 110℃. Based on the total weight of the catalyst, the spraying amount of the active component is 10wt%. Place the sprayed catalyst in a muffle furnace and calcine at 450℃ for 3 hours. After natural cooling, the catalyst is obtained. Using mesitylene and air as raw materials, a fixed-bed reactor was used to prepare homohydric anhydride in the presence of a catalyst; the reaction process and temperature conditions were as follows: the mass concentration of mesitylene was 20 g / cm³. 3 The gas hourly space velocity is 5000 hr. -1 The reaction temperature was 390℃, and the reaction pressure was atmospheric pressure. The yield of homogeneous anhydride was measured to be 84.9 wt%. 10 g of catalyst was placed in a particle abrasion tester to determine the abrasion rate. The parameters of the instrument were: inner diameter of the grinding cylinder... The grinding cylinder is 150mm long, the inner baffle is 150mm long and 18mm high, the grinding cylinder speed is 30r / min, and the grinding time is 10min. The catalyst wear rate was measured to be 0.19%.

[0115] As can be seen from Examples 6 and 7, within the scope of this invention, by changing the preparation conditions, the zinc oxide nanowires prepared are still an excellent inert support for the gas-phase oxidation of mesitylene to homohydric anhydride catalyst.

[0116] Example 8

[0117] A spray-coated catalyst for the production of homogeneous anhydride was prepared. The support was zinc oxide nanowires prepared in Preparation Example 4, the vanadium source was ammonium metavanadate, the titanium source was titanium dioxide, and the co-catalyst components were phosphorus, niobium, and tungsten.

[0118] Weigh 80g of oxalic acid and 300mL of distilled water into a three-necked flask, stir and heat to 80℃ to completely dissolve the oxalic acid to obtain an oxalic acid solution. Slowly add 38g of ammonium metavanadate to the prepared oxalic acid solution, and continue stirring until the oxalic acid and ammonium metavanadate react completely to obtain a vanadium oxalate solution. Add 1.2g of ammonium dihydrogen phosphate, 0.4g of niobium oxalate, and 0.6g of ammonium metatungstate to the solution. Add 120g of titanium dioxide to the solution, control the solution temperature at 80℃ and stir for 6 hours. Take a certain mass of the zinc oxide nanowire carrier obtained in Preparation Example 3 above and place it in a sprayer. Spray the above slurry evenly onto the zinc oxide nanowire carrier at a spraying temperature of 110℃. Based on the total weight of the catalyst, the spraying amount of the active component is 10wt%. Place the sprayed catalyst in a muffle furnace and calcine at 450℃ for 3 hours. After natural cooling, the catalyst is obtained. Using mesitylene and air as raw materials, a fixed-bed reactor was used to prepare homohydric anhydride in the presence of a catalyst; the reaction process and temperature conditions were as follows: the mass concentration of mesitylene was 20 g / cm³. 3 The gas hourly space velocity is 5000 hr. -1 The reaction temperature was 390℃, and the reaction pressure was atmospheric pressure. The yield of homogeneous anhydride was measured to be 82.2 wt%. 10 g of catalyst was placed in a particle abrasion tester to determine the abrasion rate. The parameters of the instrument were: inner diameter of the grinding cylinder... The grinding cylinder is 150mm long, the inner baffle is 150mm long and 18mm high, the grinding cylinder speed is 30r / min, and the grinding time is 10min. The catalyst wear rate was measured to be 0.32%.

[0119] As shown in Example 8, changing the mass ratio of water to ethanol during the preparation of zinc oxide nanowires affects their carrier effect. Excessively increasing the mass ratio of water to ethanol during the preparation process leads to a deterioration in the carrier performance of zinc oxide nanowires, while zinc oxide nanowires with a high aspect ratio and one-dimensional linear structure exhibit excellent carrier performance.

[0120] Comparative Example 1

[0121] A spray-molded catalyst for the production of homogeneous anhydride was prepared. The support was nano-zinc oxide (catalyst Z820772) manufactured by McLean, the vanadium source was ammonium metavanadate, the titanium source was titanium dioxide, and the co-catalytic components were phosphorus, niobium, and tungsten.

[0122] Weigh 80g of oxalic acid and 300mL of distilled water into a three-necked flask, stir and heat to 80℃ to completely dissolve the oxalic acid to obtain an oxalic acid solution. Slowly add 38g of ammonium metavanadate to the prepared oxalic acid solution, and continue stirring until the oxalic acid and ammonium metavanadate react completely to obtain a vanadium oxalate solution. Add 1.2g of ammonium dihydrogen phosphate, 0.4g of niobium oxalate, and 0.6g of ammonium metatungstate to the solution. Add 120g of titanium dioxide to the solution, control the solution temperature at 80℃ and stir for 6 hours. Take a certain mass of the above-prepared pressed nano-zinc oxide carrier and place it in a spraying machine. Spray the above slurry evenly onto the zinc oxide nanowire carrier at a spraying temperature of 110℃. Based on the total weight of the catalyst, the spraying amount of the active component is 10wt%. Place the sprayed catalyst in a muffle furnace and calcine at 450℃ for 3 hours. After natural cooling, the catalyst is obtained. Using mesitylene and air as raw materials, a fixed-bed reactor was used to prepare homohydric anhydride in the presence of a catalyst; the reaction process and temperature conditions were as follows: the mass concentration of mesitylene was 20 g / cm³. 3 The gas hourly space velocity is 5000 hr. -1 The reaction temperature was 390℃, and the reaction pressure was atmospheric pressure. The yield of homogeneous anhydride was measured to be 76.3 wt%. 10 g of catalyst was placed in a particle abrasion tester to determine the abrasion rate. The parameters of the instrument were: inner diameter of the grinding cylinder... The grinding cylinder is 150mm long, the inner baffle is 150mm long and 18mm high, the grinding cylinder speed is 30r / min, and the grinding time is 10min. The catalyst wear rate was measured to be 0.44%.

[0123] Comparative Example 2

[0124] A spray-molded catalyst for the production of homogeneous anhydride was prepared. The support was an industrial-grade ceramic ring, the vanadium source was ammonium metavanadate, the titanium source was titanium dioxide, and the co-catalyst components were phosphorus, niobium, and tungsten.

[0125] Weigh 80g of oxalic acid and 300mL of distilled water into a three-necked flask, stir and heat to 80℃ to completely dissolve the oxalic acid to obtain an oxalic acid solution. Slowly add 38g of ammonium metavanadate to the prepared oxalic acid solution, and continue stirring until the oxalic acid and ammonium metavanadate react completely to obtain a vanadium oxalate solution. Add 1.2g of ammonium dihydrogen phosphate, 0.4g of niobium oxalate, and 0.6g of ammonium metatungstate to the solution. Add 120g of titanium dioxide to the solution, and stir for 6 hours while maintaining the solution temperature at 80℃. Place a certain mass of the above-mentioned ceramic ring carrier into a sprayer, and spray the above slurry evenly onto the zinc oxide nanowire carrier at a spraying temperature of 110℃. Based on the total weight of the catalyst, the spraying amount of the active component is 10wt%. Place the sprayed catalyst in a muffle furnace, calcine at 450℃ for 3 hours, and obtain the catalyst after natural cooling. Using mesitylene and air as raw materials, a fixed-bed reactor was used to prepare homohydric anhydride in the presence of a catalyst; the reaction process and temperature conditions were as follows: the mass concentration of mesitylene was 20 g / cm³. 3 The gas hourly space velocity is 5000 hr. -1 The reaction temperature was 390℃, and the reaction pressure was atmospheric pressure. The yield of homogeneous anhydride was measured to be 80.1 wt%. 10 g of catalyst was placed in a particle abrasion tester to determine the abrasion rate. The parameters of the instrument were: inner diameter of the grinding cylinder... The grinding cylinder is 150mm long, the inner baffle is 150mm long and 18mm high, the grinding cylinder speed is 30r / min, and the grinding time is 10min. The catalyst wear rate was measured to be 0.63%.

[0126] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

[0127] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalyst for the gas-phase oxidation of mesitylene to homohydric anhydride, characterized in that, The catalyst comprises an inert support and an active component; the inert support is zinc oxide nanorods. Based on the total weight of the catalyst, the content of the support is 60-97 wt%, and the content of the active component, based on the weight of its corresponding oxide, is 1-50 wt%. The active components of the catalyst include a main active component oxide and a co-active component element oxide; the main active component oxide includes vanadium oxide and titanium oxide, and the co-active component element is selected from at least one of a transition metal element and a non-metal element, wherein the transition metal element includes one or more of zirconium, niobium and tungsten, and the non-metal element includes one or more of phosphorus and boron.

2. The catalyst according to claim 1, wherein, Zinc oxide nanorods exhibit distinct diffraction peaks at 2θ values ​​of 31.9°, 34.5°, and 36.3°; and / or The aspect ratio of zinc oxide nanorods is 40-130; and / or The zinc oxide nanorods have a length of 3.0–3.9 μm; and / or The zinc oxide nanorods have a diameter of 30-70 nm; and / or The zinc oxide nanorods have a hexagonal zinc oxide crystal phase.

3. The catalyst according to claim 2, wherein, The aspect ratio of zinc oxide nanorods is 42-55.

4. The catalyst according to claim 1 or 2, wherein, Based on the total weight of the catalyst, the content of the active component, calculated by weight of its corresponding oxide, is 3-40 wt%; and / or The mass ratio of the vanadium oxide, titanium oxide, and auxiliary active component element oxide is (0.005-0.5):1:(0.003-0.28).

5. The catalyst according to claim 4, wherein, The mass ratio of the vanadium oxide, titanium oxide, transition metal oxide, and non-metal oxide is (0.005-0.5):1:(0.0001-0.2):(0.001-0.08); and / or The active ingredients include niobium oxide, tungsten oxide, and phosphorus oxide.

6. The catalyst according to claim 5, wherein, The mass ratio of vanadium oxide, titanium oxide, transition metal oxide, and non-metal oxide is (0.05-0.45):1:(0.0005-0.002):(0.002-0.05); and / or The mass ratio of niobium oxide, tungsten oxide and phosphorus oxide is 0.01-1:0.01-1:

1.

7. The catalyst according to claim 1 or 2, wherein, The method for preparing the inert carrier includes the following steps: (1) Obtain a mixed solution comprising zinc source, polyethylene glycol, water, ethanol and sodium hydroxide; (2) Transfer the mixed solution to a hydrothermal reactor for hydrothermal reaction; (3) After the hydrothermal reaction is complete, the reaction product is washed, filtered, dried, calcined and optionally shaped. In step (1), the mass ratio of water to ethanol is 0-2:

1.

8. The catalyst according to claim 7, wherein, In step (1), the mass ratio of water to ethanol is 0.005-0.5:1; and / or In step (1), the polyethylene glycol is one or more of polyethylene glycol 2000, polyethylene glycol 10000 and polyethylene glycol 20000.

9. The catalyst according to claim 8, wherein, In step (1), the polyethylene glycol is polyethylene glycol 20000.

10. The catalyst according to claim 7, wherein, In step (1), the zinc source is one or more of zinc acetate, zinc sulfate, and zinc nitrate; and / or The weight ratio of zinc source, polyethylene glycol, water, ethanol, and sodium hydroxide is 0.001-0.1:0.001-0.1:0.005-0.5:1:0.01-0.1; and / or In step (2), the conditions for the hydrothermal reaction include: a reaction temperature of 80-200℃; and / or a reaction time of 8-24 h; In step (3), the detergent is one or more of water, methanol, and ethanol; The drying temperature is 40-100℃; and / or The roasting temperature is 300-600℃; and / or The forming method is extrusion and / or tableting.

11. The catalyst according to claim 10, wherein, In step (1), the zinc source is zinc acetate; and / or In step (2), the conditions for the hydrothermal reaction include: a reaction temperature of 100-150℃; and / or a reaction time of 10-18 h; In step (3), the detergent is water and / or ethanol; The drying temperature is 60-80℃; and / or The roasting temperature is 400-500℃.

12. A method for preparing the catalyst according to any one of claims 1-11, characterized in that, The method includes: (a) Obtaining zinc oxide nanorods to serve as inert supports; (b) Obtaining a precursor slurry containing the catalyst active component; (c) The precursor slurry is sprayed onto zinc oxide nanorods by a spraying method and then calcined to obtain the catalyst.

13. The preparation method according to claim 12, wherein, The active components of the catalyst include a main active component oxide and a co-active component element oxide. The main active component oxide includes vanadium oxide and titanium oxide. The co-active component element is selected from at least one of the transition metal elements and non-metal elements. The vanadium source is one or more of metavanadate, vanadium oxide, and orthovanadate; and / or The titanium source is one or more of titanates, titanium oxides, and titanium halides.

14. The preparation method according to claim 13, wherein, When the auxiliary active component element is one or more of zirconium, niobium, tungsten, phosphorus and boron; The zirconium source is at least one of zirconium oxide and zirconium silicate; The niobium source is at least one of niobium oxalate and niobium pentachloride; The tungsten source is at least one of tungstic acid and ammonium metatungstate; The phosphorus source is at least one of phosphoric acid and ammonium dihydrogen phosphate; The boron source is at least one of boric acid and ammonium pentaborate.

15. The preparation method according to claim 12, wherein, In step (c), Spraying temperature 60-180℃; and / or The roasting temperature is 350-500℃.

16. The preparation method according to claim 15, wherein, In step (c), The spraying temperature is 80-160℃; and / or The roasting temperature is 400-480℃.

17. A method for producing homogenizing anhydride, characterized in that, A fixed-bed reactor is used, in the presence of the catalyst described in any one of claims 1-11, to contact the feedstock mesitylene with an oxygen-containing gas, wherein the contact conditions include: a mesitylene mass concentration of 10-40 g / cm³. 3 The volumetric hourly space velocity (VHSV) is 4000-8000 hr. -1 The reaction temperature is 350-500℃ and the reaction pressure is atmospheric pressure.

18. The method according to claim 17, wherein, The contact conditions include a mesitylene mass concentration of 15-30 g / cm³. 3 The gas hourly space velocity is 4000-6000 hr. -1 The reaction temperature is 360-480℃, the reaction pressure is atmospheric pressure, and the oxygen-containing gas is air.

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