Catalyst for toluene oxidation to benzaldehyde and preparation method and application thereof

Abstract

The present application relates to the technical field of toluene oxidation to prepare benzaldehyde, and discloses a catalyst with the function of toluene oxidation to prepare benzaldehyde, a preparation method and application thereof, the catalyst comprises a carrier and an active component loaded on the carrier, the active component comprises a first active component and an optional second active component, wherein the first active component comprises V2O5 and TiO2, and the second active component comprises at least one of K2O, Na2O, Rb2O, Cs2O, CeO2, P2O5, Co2O3, Nb2O5, Cr2O3, Ag2O, Sb2O3, Bi2O3 and MoO3. When the catalyst is used for preparing benzaldehyde through toluene gas-phase oxidation, the conversion rate of toluene can reach more than 28%, the selectivity of benzaldehyde can reach 50%, and the yield can reach 14%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of toluene oxidation to benzaldehyde, in particular to a catalyst with toluene oxidation to benzaldehyde function and its preparation method and application. BACKGROUND

[0002] Benzaldehyde is one of the important aromatic aldehydes, mainly used in the fields of dyes, pharmaceuticals, pesticides, fuels, perfumes, cosmetics and organic polymer synthesis, etc., with the characteristics of large annual demand, good market prospect and high economic benefit. According to statistics, the demand for benzaldehyde in China is increasing at a rate of about 7% per year, and the current market demand is about 90 kt / a.

[0003] At present, the traditional process is still mainly used at home and abroad, that is, the side CH3 functional group of chlorinated toluene is hydrolyzed by saponification to produce benzaldehyde. This process will produce a large amount of wastewater, resulting in environmental pollution and equipment corrosion; the product benzaldehyde contains toxic chlorides, which seriously limits its use in the synthesis of some high-quality compounds such as pharmaceuticals and perfumes. Therefore, it is an inevitable trend to explore clean synthesis process of benzaldehyde.

[0004] At present, the clean process of toluene oxidation to benzaldehyde includes gas phase method and liquid phase method, which has become a research hotspot. Compared with liquid phase, the reaction conditions of gas phase oxidation in fixed bed at room temperature are relatively mild, and the product is easier to separate.

[0005] In order to improve the conversion rate of toluene and the selectivity of benzaldehyde, in addition to improving the process, the performance of the catalyst is the technical core of toluene gas phase oxidation. SUMMARY

[0006] The purpose of the present application is to provide a vanadium-titanium catalyst which can improve the conversion rate of toluene and the selectivity of benzaldehyde under mild conditions.

[0007] The first aspect of the present application provides a catalyst with toluene oxidation to benzaldehyde function, which comprises a carrier and an active component loaded on the carrier, the active component comprises a first active component and an optional second active component, wherein the first active component comprises V2O5 and TiO2, and the second active component comprises at least one of K2O, Na2O, Rb2O, Cs2O, CeO2, P2O5, Co2O3, Nb2O5, Cr2O3, Ag2O, Sb2O3, Bi2O3 and MoO3.

[0008] The second aspect of the present application provides a method for preparing a catalyst with the function of preparing benzaldehyde from toluene oxidation, which comprises: loading an active component on a carrier, wherein the active component comprises a first active component and an optional second active component, wherein the first active component comprises V2O5 and TiO2, and the second active component comprises at least one of K2O, Na2O, Rb2O, Cs2O, CeO2, P2O5, Co2O3, Nb2O5, Cr2O3, Ag2O, Sb2O3, Bi2O3 and MoO3.

[0009] The third aspect of the present application provides a catalyst prepared by the method of the second aspect.

[0010] The fourth aspect of the present application provides an application of the catalyst of the first aspect and the third aspect in preparing benzaldehyde from toluene oxidation.

[0011] The fifth aspect of the present application provides a method for preparing benzaldehyde from toluene oxidation, which comprises: contacting toluene with oxygen in the presence of the catalyst of the first aspect and the third aspect.

[0012] Alternatively, the catalyst is prepared according to the method of the second aspect, and then toluene is contacted with oxygen in the presence of the obtained catalyst.

[0013] Through the above technical solutions, the present application has the following beneficial effects:

[0014] (1) The vanadium oxide, titanium oxide, potassium oxide and antimony oxide in the catalyst of the present application cooperate with each other to improve the conversion rate of toluene and the selectivity of benzaldehyde, thereby improving the yield of benzaldehyde in the product.

[0015] (2) The present application coats the vanadium source, titanium source, potassium source and antimony source on the carrier by the spraying method, and the preparation method is simple.

[0016] (3) The catalyst prepared by the present application can directly oxidize toluene in gas phase to obtain benzaldehyde, and no toxic gas and waste acid are generated in the reaction process, which almost has no impact on the environment and belongs to the environment-friendly green process. When the catalyst is used for preparing benzaldehyde from toluene gas phase oxidation, the conversion rate of toluene can reach more than 28%, the selectivity of benzaldehyde can reach 50%, and the yield can reach 14%. DETAILED DESCRIPTION

[0017] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not considered critical for the purposes of the application. The ranges should be interpreted as being inclusive of the recited values and the ranges between the recited values. For values which are less than one, combinations of the upper and lower limits of the range can be made to cover the intended range. For values which are greater than one, combinations of the upper limit of the range with the lower limit of the next range can be made to cover the intended range.

[0018] The first aspect of the present application provides a catalyst for toluene oxidation to benzaldehyde, which comprises a carrier and an active component supported on the carrier, wherein the active component comprises a first active component and an optional second active component, and the first active component comprises V2O5 and TiO2, and the second active component comprises at least one of K2O, Na2O, Rb2O, Cs2O, CeO2, P2O5, Co2O3, Nb2O5, Cr2O3, Ag2O, Sb2O3, Bi2O3 and MoO3.

[0019] According to the present application, preferably, the weight ratio of the carrier and the active component is 100:8-18, more preferably 100:10-15. Wherein the weight ratio of the carrier and the active component refers to 10-15 g of the active component supported per 100 g of the carrier.

[0020] According to the present application, preferably, the second active component comprises K2O and / or Sb2O3, more preferably, the second active component comprises K2O and Sb2O3.

[0021] According to the present application, the type of the carrier has a wide range of selection, and the carrier can be of a type conventional in the art. Preferably, the carrier is an inert carrier (non-porous inert carrier) selected from at least one of talc, silicon carbide, aluminum silicate, quartz and ceramic, preferably talc.

[0022] In the present application, the shape of the carrier is not particularly limited, for example, it can be cylindrical, spherical, annular or granular. Preferably, the shape of the carrier is an annular carrier.

[0023] According to the present application, preferably, the weight ratio of the first active component and the second active component is 50-130, preferably 59-122.

[0024] According to the present application, preferably, the weight ratio of TiO2 and V2O5 is 6-13, more preferably 6.5-12.1, further preferably 7-10.

[0025] According to the present application, preferably, the weight ratio of K2O and Sb2O3 is 0.5-5, more preferably 1-3.2, further preferably 1.7-2.

[0026] In the present application, the content of each component in the active component of the catalyst is calculated based on the amount of the raw material.

[0027] According to the present application, preferably, the content of V2O5 is 7.5-13.5wt%, preferably 9-12wt%, the content of TiO2 is 85-91wt%, preferably 86-90.2wt%, the content of K2O is 0.1-1wt%, preferably 0.2-0.6wt%, and the content of Sb2O3 is 0.1-2wt%, preferably 0.5-1.5wt%, based on the total weight of the active component. The preferred conditions are more conducive to improving the catalytic activity of the catalyst.

[0028] More preferably, the active component of the catalyst in the present application does not include the oxide of cesium.

[0029] The second aspect of the present application provides a method for preparing a catalyst with the function of toluene oxidation to produce benzaldehyde, which comprises: loading an active component on a carrier, wherein the active component comprises a first active component and an optional second active component, wherein the first active component comprises V2O5 and TiO2, and the second active component comprises at least one of K2O, Na2O, Rb2O, Cs2O, CeO2, P2O5, Co2O3, Nb2O5, Cr2O3, Ag2O, Sb2O3, Bi2O3 and MoO3.

[0030] According to the present application, preferably, the amount of the carrier and the active component is such that the weight ratio of the carrier to the active component in the obtained catalyst is 100:8-18, more preferably 100:10-15.

[0031] According to the present application, preferably, the second active component comprises K2O and / or Sb2O3; more preferably, the second active component comprises K2O and Sb2O3.

[0032] According to the present application, the type of the carrier has a wide range of choices, and the carrier can be of a type conventional in the art. Preferably, the carrier is an inert carrier (non-porous inert carrier) selected from at least one of talc, silicon carbide, aluminum silicate, quartz and ceramic, preferably talc.

[0033] In the present application, the shape of the carrier is not particularly limited, for example, it can be cylindrical, spherical, annular or granular. Preferably, the shape of the carrier is an annular carrier.

[0034] According to the present application, preferably, the amount of the active component is such that the weight ratio of the first active component to the second active component in the obtained catalyst is 50-130, preferably 59-122.

[0035] According to the present application, preferably, the active first component is used in an amount such that the weight ratio of TiO2 and V2O5 in the obtained catalyst is 6-13, more preferably 6.5-12.1, and further preferably 7-10.

[0036] According to the present application, preferably, the active second component is used in an amount such that the weight ratio of K2O and Sb2O3 in the obtained catalyst is 0.5-5, more preferably 1-3.2, and further preferably 1.7-2.

[0037] According to the present application, the loading amount of the active components can be controlled as required, and in order to obtain better catalytic effect, preferably, the active components are used in an amount such that the V2O5 content is 7.5-13.5wt%, preferably 9-12wt%, the TiO2 content is 85-91wt%, preferably 86-90.2wt%, the K2O content is 0.1-1wt%, preferably 0.2-0.6wt%, and the Sb2O3 content is 0.1-2wt%, preferably 0.5-1.5wt%, based on the total weight of the active components in the obtained catalyst. Using the preferred conditions is more conducive to improving the catalytic activity of the catalyst.

[0038] According to the present application, preferably, the loading method comprises coating the carrier with a slurry containing a precursor of the active component, and then activating.

[0039] More preferably, the loading method comprises coating the carrier with a slurry containing a vanadium source, an optional potassium source, an optional antimony source, and a titanium source, and then activating.

[0040] According to the present application, preferably, the preparation method of the slurry comprises:

[0041] (1) mixing an organic acid, a vanadium source, and a potassium source in the presence of a solvent to obtain a solution;

[0042] (2) mixing the solution obtained in step (1) with a titanium source and an antimony source to obtain a slurry;

[0043] According to the present application, preferably, in the slurry, the amount of the organic acid is 20-60g, preferably 24-46g, per 100g of the titanium source.

[0044] According to the present application, preferably, in the slurry, the amount of the solvent is 200-280g, preferably 220-250g, per 100g of the titanium source.

[0045] According to the present application, preferably, the solvent comprises water and / or a water-soluble organic solvent. More preferably, the weight ratio of the water and the water-soluble organic solvent is 5-7:1.

[0046] According to the present application, preferably, the organic acid is oxalic acid.

[0047] In the present application, the water-soluble organic solvent refers to an organic solvent which is easily soluble in water, or an organic solvent which is easily soluble in water with the aid of an additive, unless otherwise specified. Preferably, the water-soluble organic solvent includes at least one of methanol, ethanol, formamide and N,N-dimethylformamide.

[0048] According to the present application, the active component precursor can be a common substance capable of providing the metal element in the above metal oxide (first active component or second active component), such as a salt, an oxide, a hydroxide, etc.

[0049] According to the present application, the vanadium source can be selected from a wide range of categories. Preferably, the vanadium source is selected from at least one of vanadyl oxalate, ammonium metavanadate and di vanadium pentoxide, and more preferably, the vanadium source is ammonium metavanadate.

[0050] According to the present application, the potassium source can be selected from a wide range of categories. Preferably, the potassium source is selected from at least one of potassium oxalate, potassium hydroxide, potassium carbonate, potassium sulfate and potassium chloride.

[0051] According to the present application, the antimony source can be selected from a wide range of categories. Preferably, the antimony source is selected from SbCl5 and / or Sb2O3.

[0052] According to the present application, the titanium source can be selected from a wide range of categories. Preferably, the titanium source is anatase TiO2, and more preferably, the specific surface area of the anatase TiO2 is 10-50 m 2 / g, and preferably, 15-25 m 2 / g.

[0053] According to the present application, in order to accelerate the volatilization of water and the soluble organic solvent in the slurry, so as to quickly and effectively adhere the active component, preferably, the coating is performed at an environment of 80-150°C, and more preferably, the coating is performed at an environment of 80-150°C. The heat carrier used in the coating process can be air.

[0054] According to the present application, preferably, the coating method is spraying. The spraying rate of the slurry satisfies that the weight gain of the carrier is 0.5-0.75 g / min, and preferably, 0.4-0.6 g / min, per 100 g of the carrier. Controlling the spraying rate within the above defined range can prevent the waste of the slurry and the loss of the active component in the slurry.

[0055] According to the present application, the spraying device is not particularly limited as long as it can meet the spraying requirement.

[0056] According to the present application, in order to make the slurry more easily adhere to the carrier, preferably, the carrier is heated to 80-150℃ (hot carrier) before spraying, preferably 100-130℃.

[0057] According to the present application, preferably, the second mixing method is not particularly limited, preferably, the second mixing method is grinding, for example, wet grinding method can be used; considering the convenience and timeliness of grinding, more preferably, the second mixing time is 1-5h, preferably 2-4h.

[0058] According to the present application, preferably, the second mixing is completed in a ball mill.

[0059] According to the present application, preferably, the viscosity of the slurry is 12-20Pa·s.

[0060] According to the present application, in order to make the coating have certain bonding strength with the carrier, preferably, the preparation method of the slurry further comprises adding a binder in step (2), more preferably, the binder is one of organic binders, preferably one of vinyl acetate-acrylate copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-maleate copolymer and acrylic acid-maleic acid copolymer.

[0061] Since high temperature can cause the binder to disappear, reduce the adhesion of the active component on the catalyst, and thus cause the active component to fall off during catalyst loading, in order to avoid the active component from falling off during catalyst loading, preferably, the carrier coated with the active component is activated before reaction, specifically: the carrier coated with the active component (catalyst precursor) is loaded into the reactor first, and then activated.

[0062] According to the present application, the activation conditions can be selected in a wide range. Preferably, the activation temperature is 380-420℃, and the time is 2-8h.

[0063] The third aspect of the present application provides a catalyst prepared by the method of the second aspect.

[0064] The fourth aspect of the present application provides the use of the catalyst of the first aspect and the third aspect in the oxidation of toluene to prepare benzaldehyde.

[0065] The fifth aspect of the present application provides a method for preparing benzaldehyde by oxidizing toluene, which comprises: contacting toluene with oxygen in the presence of the catalyst of the first aspect and the third aspect.

[0066] Alternatively, the catalyst is prepared according to the method of the second aspect, and then toluene is contacted with oxygen in the presence of the obtained catalyst.

[0067] According to the present application, preferably, the contacting conditions include: temperature (molten salt) is 340-400℃, pressure is 0.05-0.15MPa, the feed molar ratio of toluene and air is 1:2-10, preferably 1:5-8; the space velocity of toluene is 1000-3000h -1 .

[0068] According to the present application, the reaction of toluene to benzaldehyde is carried out in a fixed bed single tube reactor. The outer part of the reaction tube of the fixed bed single tube reactor is forced to exchange reaction heat by circulating molten salt, and the reaction tube has a thermowell with an outer diameter of 5-10mm, and several thermocouples with the same spacing in the thermowell, which are used to measure the temperature of the reaction bed and the temperature of the molten salt, wherein the highest value of the temperature zone is called the reaction hot spot temperature. The outlet of the fixed bed single tube reactor is connected to a product trapping device, and a sampling port is provided at the lower end outlet of the reaction tube.

[0069] According to the present application, the fixed bed single tube reactor is not limited, and can be selected as needed. The tube length of the reaction tube used in the present application is 1400mm, and the inner diameter is 24mm. The catalyst in the reaction tube of the fixed bed single tube reactor is loaded in a single section, and the total loading height is 1000mm.

[0070] The present application will be described in detail below through examples.

[0071] The catalytic product is analyzed by chromatographic analysis and chemical titration method;

[0072] The calculation formula of the conversion rate (%) of toluene is:

[0073]

[0074] The calculation formula of the selectivity (%) of benzaldehyde is:

[0075]

[0076] The calculation formula of the yield (%) of benzaldehyde is:

[0077] The yield of benzaldehyde = conversion rate of toluene x selectivity of benzaldehyde x 100%.

[0078] Example 1

[0079] (1) 61.3g of ammonium metavanadate, 141.4g of oxalic acid, 2.85g of potassium oxalate, 135mL of formamide, and 800g of water are mixed to form a transparent solution.

[0080] (2) The solution prepared in step (1), 400 g of titanium dioxide, 3.84 g of antimony trioxide, 40 g of vinyl acetate / ethylene copolymer emulsion, were poured into a ball mill, and the catalytically active components were emulsified into a uniform slurry (suspension) by ball milling for 4 h, with the viscosity controlled to be 12 Pa-S to 20 Pa-S.

[0081] (3) 2 kg of talc rings as carriers (outer diameter 8 mm, height 6 mm, wall thickness 1.5 mm) were placed in a rotating drum of a spray coating device, and the rotating drum speed was controlled to be 8 rpm. The slurry prepared in step (2) was stirred in a stirring tank of a liquid spray system, and a hot air blower was turned on, and hot air was blown into the rotating drum to preheat the carrier rings. When the temperature of the carrier rings reached 120°C, the atomizing and feeding nozzles were turned on, and the temperature of the hot air was controlled to be 120°C, and the spraying rate was controlled to be 0.5 g / min per 100 g of the carrier. The first slurry was sprayed onto the surface of the carrier rings through the nozzles, and was rapidly dried by the hot air. The content of the active components reached 12 wt% of the weight of the carrier, and a catalyst precursor was obtained.

[0082] (4) The catalyst precursor was loaded into a fixed bed reactor, the reaction tube was 1400 mm long and had an inner diameter of 24 mm, the loading height was 1000 mm, and 450 g of the catalyst was loaded. The reactor was heated to 400°C, and was activated at a constant temperature for 2 h to obtain the catalyst.

[0083] The active components in the catalyst include V2O5, K2O, Sb2O3, and TiO2.

[0084] The content of V2O5 is 10.51 wt%, the content of K2O is 0.36 wt%, the content of Sb2O3 is 0.85 wt%, and the content of TiO2 is 88.28 wt% by weight based on the content of the active components.

[0085] Example 2

[0086] (1) 51.5 g of ammonium metavanadate, 118.8 g of oxalic acid, 1.84 g of potassium oxalate, 135 mL of formamide, and 800 g of water were mixed to form a transparent solution.

[0087] (2) The solution prepared in step (1), 400 g of titanium dioxide, 2.58 g of antimony trioxide, 40 g of vinyl acetate / ethylene copolymer emulsion, were poured into a ball mill, and the catalytically active components were emulsified into a uniform slurry by ball milling for 4 h, with the viscosity controlled to be 12 Pa-S to 20 Pa-S.

[0088] (3) The same as step (3) of Example 1.

[0089] (4) The same as step (4) of Example 1.

[0090] The active components in the catalyst include V2O5, K2O, Sb2O3, and TiO2.

[0091] wherein, based on the content of the active component, the V2O5 content is 9.02 wt%, the K2O content is 0.23 wt%, the Sb2O3 content is 0.58 wt%, and the TiO2 content is 90.17 wt%.

[0092] Example 3

[0093] (1) 71.8 g of ammonium metavanadate, 165.7 g of oxalic acid, 4.11 g of potassium oxalate, 135 mL of formamide, and 800 g of water were mixed to form a transparent solution.

[0094] (2) The solution prepared in step (1), 400 g of titanium dioxide, 5.39 g of antimony trioxide, and 40 g of a vinyl acetate / ethylene copolymer emulsion were poured into a ball mill, and the catalytically active components were emulsified into a uniform slurry with a viscosity controlled to 12 Pa-S to 20 Pa-S.

[0095] (3) The same as step (3) of Example 1.

[0096] (4) The same as step (4) of Example 1.

[0097] wherein the active component of the catalyst contains V2O5, K2O, Sb2O3, and TiO2;

[0098] wherein, based on the content of the active component, the V2O5 content is 12.04 wt%, the K2O content is 0.5 wt%, the Sb2O3 content is 1.16 wt%, and the TiO2 content is 86.3 wt%.

[0099] Example 4

[0100] (1) 42.7 g of ammonium metavanadate, 98.6 g of oxalic acid, 4.68 g of potassium oxalate, 135 mL of formamide, and 800 g of water were mixed to form a transparent solution.

[0101] (2) The solution prepared in step (1), 400 g of titanium dioxide, 3.84 g of antimony trioxide, and 40 g of a vinyl acetate / ethylene copolymer emulsion were poured into a ball mill, and the catalytically active components were emulsified into a uniform slurry with a viscosity controlled to 12 Pa-S to 20 Pa-S.

[0102] (3) The same as step (3) of Example 1.

[0103] (4) The same as step (4) of Example 1.

[0104] wherein the active component of the catalyst contains V2O5, K2O, Sb2O3, and TiO2;

[0105] wherein, based on the content of the active component, the V2O5 content is 7.55 wt%, the K2O content is 0.6 wt%, the Sb2O3 content is 0.87 wt%, and the TiO2 content is 91 wt%.

[0106] Example 5

[0107] (1) 79.1 g of ammonium metavanadate, 182.5 g of oxalic acid, 1.52 g of potassium oxalate, 135 mL of formamide, and 800 g of water were mixed to form a transparent solution.

[0108] (2) The solution prepared in step (1), 400 g of titanium dioxide, 3.84 g of antimony trioxide, and 40 g of a vinyl acetate / ethylene copolymer emulsion were poured into a ball mill, and ball-milled for 4 h to emulsify the catalytically active components into a uniform slurry, and the viscosity was controlled to be 12 Pa-S to 20 Pa-S.

[0109] (3) The same as step (3) of Example 1.

[0110] (4) The same as step (4) of Example 1.

[0111] wherein the active component of the catalyst contains V2O5, K2O, Sb2O3, and TiO2;

[0112] wherein, based on the content of the active component, the V2O5 content is 13.19 wt%, the K2O content is 0.18 wt%, the Sb2O3 content is 0.82 wt%, and the TiO2 content is 85.8 wt%.

[0113] Example 6

[0114] (1) 61.3 g of ammonium metavanadate, 141.4 g of oxalic acid, 1.84 g of potassium oxalate, 135 mL of formamide, and 800 g of water were mixed to form a transparent solution.

[0115] (2) The solution prepared in step (1), 400 g of titanium dioxide, 3.84 g of antimony trioxide, and 40 g of a vinyl acetate / ethylene copolymer emulsion were poured into a ball mill, and ball-milled for 4 h to emulsify the catalytically active components into a uniform slurry, and the viscosity was controlled to be 12 Pa-S to 20 Pa-S.

[0116] (3) The same as step (3) of Example 1.

[0117] (4) The same as step (4) of Example 1.

[0118] wherein the active component of the catalyst contains V2O5, K2O, Sb2O3, and TiO2;

[0119] wherein, based on the content of the active component, the V2O5 content is 10.53 wt%, the K2O content is 0.23 wt%, the Sb2O3 content is 0.85 wt%, and the TiO2 content is 88.4 wt%.

[0120] Example 7

[0121] (1) 61.3 g of ammonium metavanadate, 141.4 g of oxalic acid, 2.3 g of potassium oxalate, 135 mL of formamide, and 800 g of water were mixed to prepare a transparent solution.

[0122] (2) The solution prepared in step (1), 400 g of titanium dioxide, 3.84 g of antimony trioxide, and 40 g of a vinyl acetate / ethylene copolymer emulsion were poured into a ball mill, and the catalytically active components were emulsified into a uniform slurry having a viscosity of 12 Pa-S to 20 Pa-S by ball milling for 4 h.

[0123] (3) The same as step (3) of Example 1.

[0124] (4) The same as step (4) of Example 1.

[0125] wherein the active component of the catalyst contains V2O5, K2O, Sb2O3, and TiO2;

[0126] wherein, based on the content of the active component, the V2O5 content is 10.52 wt%, the K2O content is 0.29 wt%, the Sb2O3 content is 0.85 wt%, and the TiO2 content is 88.3 wt%.

[0127] Example 8

[0128] (1) 61.3 g of ammonium metavanadate, 141.4 g of oxalic acid, 3.39 g of potassium oxalate, 135 mL of formamide, and 800 g of water were mixed to prepare a transparent solution.

[0129] (2) The solution prepared in step (1), 400 g of titanium dioxide, 3.84 g of antimony trioxide, and 40 g of a vinyl acetate / ethylene copolymer emulsion were poured into a ball mill, and the catalytically active components were emulsified into a uniform slurry having a viscosity of 12 Pa-S to 20 Pa-S by ball milling for 4 h.

[0130] (3) The same as step (3) of Example 1.

[0131] (4) The same as step (4) of Example 1.

[0132] wherein the active component of the catalyst contains V2O5, K2O, Sb2O3, and TiO2;

[0133] wherein, based on the content of the active component, the V2O5 content is 10.5 wt%, the K2O content is 0.42 wt%, the Sb2O3 content is 0.85 wt%, and the TiO2 content is 88.2 wt%.

[0134] Example 9

[0135] (1) 61.3 g of ammonium metavanadate, 141.4 g of oxalic acid, 4.1 g of potassium oxalate, 135 mL of formamide, and 800 g of water were mixed to form a transparent solution.

[0136] (2) The solution prepared in step (1), 400 g of titanium dioxide, 3.84 g of antimony trioxide, and 40 g of a vinyl acetate / ethylene copolymer emulsion were poured into a ball mill, and the catalytically active components were emulsified into a uniform slurry with a viscosity of 12 Pa-S to 20 Pa-S by ball milling for 4 h.

[0137] (3) The same as step (3) of Example 1.

[0138] (4) The same as step (4) of Example 1.

[0139] wherein the active component of the catalyst contains V2O5, K2O, Sb2O3, and TiO2;

[0140] wherein, based on the content of the active component, the V2O5 content is 10.5 wt%, the K2O content is 0.51 wt%, the Sb2O3 content is 0.85 wt%, and the TiO2 content is 88.1 wt%.

[0141] Example 10

[0142] (1) 61.3 g of ammonium metavanadate, 141.4 g of oxalic acid, 4.1 g of potassium oxalate, 135 mL of formamide, and 800 g of water were mixed to form a transparent solution.

[0143] (2) The solution prepared in step (1), 400 g of titanium dioxide, 3.84 g of antimony trioxide, and 40 g of a vinyl acetate / ethylene copolymer emulsion were poured into a ball mill, and the catalytically active components were emulsified into a uniform slurry with a viscosity of 12 Pa-S to 20 Pa-S by ball milling for 4 h.

[0144] (3) The same as step (3) of Example 1.

[0145] (4) The same as step (4) of Example 1.

[0146] wherein the active component of the catalyst contains V2O5, K2O, Sb2O3, and TiO2;

[0147] wherein, based on the content of the active component, the V2O5 content is 10.5 wt%, the K2O content is 0.58 wt%, the Sb2O3 content is 0.85 wt%, and the TiO2 content is 88.1 wt%.

[0148] Example 11

[0149] (1) 51.5 g of ammonium metavanadate, 118.8 g of oxalic acid, 2.85 g of potassium oxalate, 135 mL of formamide, and 800 g of water were mixed to form a transparent solution.

[0150] (2) The solution prepared in step (1), 400 g of titanium dioxide, 3.84 g of antimony trioxide, and 40 g of a vinyl acetate / ethylene copolymer emulsion were poured into a ball mill, and ball-milled for 4 h to emulsify the catalytically active components into a uniform slurry, the viscosity of which was controlled to be 12 Pa-S to 20 Pa-S.

[0151] (3) The same as step (3) of Example 1.

[0152] (4) The same as step (4) of Example 1.

[0153] wherein the active component of the catalyst contains V2O5, K2O, Sb2O3, and TiO2;

[0154] wherein, based on the content of the active component, the V2O5 content is 9 wt%, the K2O content is 0.36 wt%, the Sb2O3 content is 0.86 wt%, and the TiO2 content is 89.8 wt%.

[0155] Example 12

[0156] (1) 71.8 g of ammonium metavanadate, 165.7 g of oxalic acid, 2.85 g of potassium oxalate, 135 mL of formamide, and 800 g of water were mixed to form a transparent solution.

[0157] (2) The solution prepared in step (1), 400 g of titanium dioxide, 3.84 g of antimony trioxide, and 40 g of a vinyl acetate / ethylene copolymer emulsion were poured into a ball mill, and ball-milled for 4 h to emulsify the catalytically active components into a uniform slurry, the viscosity of which was controlled to be 12 Pa-S to 20 Pa-S.

[0158] (3) The same as step (3) of Example 1.

[0159] (4) The same as step (4) of Example 1.

[0160] wherein the active component of the catalyst contains V2O5, K2O, Sb2O3, and TiO2;

[0161] wherein, based on the content of the active component, the V2O5 content is 12.1 wt%, the K2O content is 0.35 wt%, the Sb2O3 content is 0.83 wt%, and the TiO2 content is 86.7 wt%.

[0162] Example 13

[0163] (1) 61.3 g of ammonium metavanadate, 141.4 g of oxalic acid, 135 mL of formamide, and 800 g of water were mixed to form a transparent solution.

[0164] (2) The solution prepared in step (1), 400 g of titanium dioxide, 3.84 g of antimony trioxide, and 40 g of a vinyl acetate / ethylene copolymer emulsion were poured into a ball mill, and the catalytically active components were emulsified into a uniform slurry with a viscosity of 12 Pa-S to 20 Pa-S by ball milling for 4 h.

[0165] (3) The same as step (3) of Example 1.

[0166] (4) The same as step (4) of Example 1.

[0167] wherein the active component of the catalyst contains V2O5, Sb2O3, and TiO2;

[0168] wherein, based on the content of the active component, the V2O5 content is 10.55 wt%, the Sb2O3 content is 0.85 wt%, and the TiO2 content is 88.6 wt%.

[0169] Example 14

[0170] (1) 61.3 g of ammonium metavanadate, 141.4 g of oxalic acid, 2.07 g of cesium sulfate, 135 mL of formamide, and 800 g of water were mixed to form a transparent solution.

[0171] (2) The solution prepared in step (1), 400 g of titanium dioxide, 3.84 g of antimony trioxide, and 40 g of a vinyl acetate / ethylene copolymer emulsion were poured into a ball mill, and the catalytically active components were emulsified into a uniform slurry with a viscosity of 12 Pa-S to 20 Pa-S by ball milling for 4 h.

[0172] (3) The same as step (3) of Example 1.

[0173] (4) The same as step (4) of Example 1.

[0174] wherein the active component of the catalyst contains V2O5, Cs2O, Sb2O3, and TiO2;

[0175] The content of V2O5 is 10.5 wt%, the content of Cs2O is 0.36 wt%, the content of Sb2O3 is 0.85 wt%, and the content of TiO2 is 88.3 wt% based on the content of the active component.

[0176] Test Example

[0177] The catalyst prepared in the above example was used in the reaction of toluene gas phase oxidation to prepare benzaldehyde. The catalyst precursor prepared in the example was loaded into a fixed bed reactor, the reaction tube was 1400 mm long, the inner diameter was 24 mm, the loading height was 1000 mm, 450 g of catalyst was loaded, the reactor was heated to 400 DEG C, and activated for 2 h to obtain the catalyst, and then cooled to 360 DEG C to feed, the raw material toluene was fed into the reactor through a constant flow pump, the space velocity was 3000 h-1, the air flow rate was 0.3 m3 / h, n (air) : n (toluene) = 5:1, the reaction pressure was 0.1 MPa, and the product was collected through an ice bath, and finally analyzed qualitatively and quantitatively by GC-MS and GC. -1

[0178] Table 1

[0179]

[0180] As can be seen from the results in Table 1, the mutual cooperation of V2O5, TiO2, K2O and Sb2O3 in the catalyst provided by the application improves the conversion rate of toluene and the selectivity of benzaldehyde, thereby improving the yield of benzaldehyde in the product. Compared with Example 13, the catalyst provided by the application contains K2O and Sb2O3, which can improve the conversion rate of toluene and the selectivity of benzaldehyde. Compared with the catalyst containing cesium oxide in Example 14, the catalyst containing V2O5, TiO2, K2O and Sb2O3 provided by the application has higher conversion rate of toluene and selectivity of benzaldehyde.

[0181] The above describes the preferred embodiments of the application in detail, but the application is not limited thereto. Within the technical concept of the application, various simple modifications can be made to the technical solutions of the application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the application and fall within the protection scope of the application.​

Claims

1. Use of a catalyst having a function of toluene oxidation to benzaldehyde in the oxidation of toluene to benzaldehyde, characterized in that, The catalyst for toluene oxidation to benzaldehyde comprises a carrier and an active component supported on the carrier, the active component comprises a first active component and a second active component, wherein the first active component comprises V2O5 and TiO2, and the second active component comprises K2O and Sb2O3; the content of V2O5 is 9-12.1 wt%, the content of TiO2 is 86-90.2 wt%, the content of K2O is 0.2-0.6 wt%, and the content of Sb2O3 is 0.5-1.5 wt% based on the total weight of the active component; The carrier is selected from at least one of talc, silicon carbide, aluminum silicate, quartz and ceramic.

2. The use according to claim 1, wherein, The weight ratio of the carrier and the active component is 100:8-18.

3. Use according to claim 2, wherein, The weight ratio of the first active component and the second active component is 50-130.

4. The use according to claim 1, wherein, The method for preparing the catalyst for toluene oxidation to benzaldehyde comprises supporting an active component on a carrier, wherein the active component comprises a first active component and a second active component, wherein the first active component comprises V2O5 and TiO2, and the second active component comprises K2O and Sb2O3; the active component is used in an amount such that, in the obtained catalyst, the content of V2O5 is 9-12.1 wt%, the content of TiO2 is 86-90.2 wt%, the content of K2O is 0.2-0.6 wt%, and the content of Sb2O3 is 0.5-1.5 wt% based on the total weight of the active component; the carrier is selected from at least one of talc, silicon carbide, aluminum silicate, quartz and ceramic.

5. Use according to claim 4, wherein, The carrier and the active component are used in an amount such that, in the obtained catalyst, the weight ratio of the carrier and the active component is 100:8-18.

6. Use according to claim 4, wherein, The active component is used in an amount such that, in the obtained catalyst, the weight ratio of the first active component and the second active component is 50-130.

7. Use according to claim 4, wherein, The supporting method comprises coating a slurry containing a precursor of the active component on the carrier, and then activating.

8. Use according to claim 7, wherein, The preparation method of the slurry comprises: (1) mixing an organic acid, a vanadium source and a potassium source in the presence of a solvent to obtain a solution; (2) mixing the solution obtained in step (1) with a titanium source and an antimony source to obtain a slurry; And / or, the coating is carried out at an environment of 80-150℃.

9. Use according to claim 8, wherein, The solvent comprises water and / or a water-soluble organic solvent; And / or, the vanadium source is selected from at least one of vanadyl oxalate, ammonium metavanadate and di vanadium pentoxide; And / or, the potassium source is selected from at least one of potassium oxalate, potassium hydroxide, potassium carbonate, potassium sulfate and potassium chloride; And / or, the antimony source is selected from SbCl5 and / or Sb2O3; And / or, the titanium source is anatase TiO2.

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