Catalyst, method for producing the same, and methods for producing α,β-unsaturated aldehyde, α,β-unsaturated carboxylic acid, and α,β-unsaturated carboxylic acid ester using the same

Abstract

The main purpose of the present invention is to provide a catalyst that makes it possible to produce an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid with high selectivity. The above is achieved by a catalyst which is used for the production of a relevant α,β-unsaturated aldehyde and / or a relevant α,β-unsaturated carboxylic acid by an oxidation reaction of a hydrocarbon, the catalyst containing molybdenum, bismuth and cobalt, wherein, with respect to the infrared absorption spectrum of the catalyst, if baseline processing is performed with the minimum absorbance in the wavenumber range of 1,000 to 1,300 cm-1 as a background, and if A1 is the maximum absorbance in the wavenumber range of 935 to 950 cm-1 and A2 is the maximum absorbance in the wavenumber range of 830 to 880 cm-1, A2 / A1 is less than 0.85.

Description

Technical Field

[0001] The present invention mainly relates to a catalyst used in the production of corresponding α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid by the oxidation reaction of hydrocarbons. More specifically, it relates to a catalyst suitably used in the production of corresponding α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid by the oxidation of propylene, isobutylene, tertiary butanol (hereinafter also referred to as "TBA"), or methyl tertiary butyl ether (hereinafter also referred to as "MTBE"), etc. This application claims priority based on Japanese Patent Application No. 2023-041837 filed in Japan on March 16, 2023, and incorporates its content herein by reference.

Background Art

[0002] As a method for producing α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid, a method of performing an oxidation reaction of hydrocarbons in the presence of a catalyst containing molybdenum and bismuth is known. As a catalyst containing molybdenum and bismuth, for example, Patent Document 1 describes that, using Raman spectroscopy, R1 = (maximum value of the peak at 886 cm -1 ±5 cm -1 ) ÷ (maximum value of the peak at 354 cm -1 ±5 cm -1 ) is a catalyst where it is 0.45 or more and 5.00 or less. Also, Patent Document 2 describes a catalyst containing molybdenum, bismuth, and cobalt as essential components, and in the X-ray diffraction pattern when the catalyst is calcined at 550°C, the ratio (J) of the maximum peak intensity in the range of X-ray diffraction angle 2θ = 28.4° ± 0.15° to the maximum peak intensity in the range of 2θ = 26.5° ± 0.3° is 36.0 or more and 57.5 or less.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0004] However, from the viewpoint of the selectivity of the target product required industrially, the catalysts described in Patent Documents 1 and 2 do not necessarily have sufficient performance. Therefore, further improvement of the catalyst performance is required.

[0005] An object of the present invention is to provide a catalyst capable of producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid with high selectivity. Another object of the present invention is to provide a method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid using this catalyst, and a method for producing an α,β-unsaturated carboxylic acid ester using the same. [Means for Solving the Problems]

[0006] As a result of intensive studies in view of the above problems, the present inventors have found that the above problems can be solved by using a catalyst in which the absorbance of the infrared absorption spectrum (hereinafter also referred to as the "IR spectrum") satisfies specific conditions, and have completed the present invention.

[0007] That is, the present invention includes the following. [1]: A catalyst used for producing a corresponding α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid by an oxidation reaction of a hydrocarbon, containing molybdenum, bismuth, and cobalt, in the infrared absorption spectrum of the catalyst, baseline processing is performed using the minimum absorbance in the range of wave numbers 1000 to 1300 cm -1 as the background, and the maximum absorbance in the range of wave numbers 935 to 950 cm -1 is A1, and the wave numbers 830 to 880 cm-1 A catalyst wherein when the maximum absorbance in the range of [2]: The catalyst according to [1], wherein A2 / A1 is 0.10 to 0.70. [3]: The catalyst according to [1] or [2], having a composition represented by the following formula (I). Mo a Bi b Fe c Co d X e Y f Si g O h ···(I) (In formula (I), Mo, Bi, Fe, Co, Si, and O represent molybdenum, bismuth, iron, cobalt, silicon, and oxygen, respectively; X represents at least one element selected from the group consisting of nickel, calcium, magnesium, niobium, tungsten, antimony, phosphorus, and titanium; Y represents at least one element selected from the group consisting of cesium, lithium, sodium, potassium, rubidium, and thallium; a, b, c, d, e, f, g, and h represent the atomic ratios of the respective elements, where a = 12, b = 0.01 to 3.00, c = 0 to 5.00, d = 1.00 to 12.00, e = 0 to 8.00, f = 0.001 to 2.00, g = 0 to 20.00, and h is the atomic ratio of oxygen necessary to satisfy the valences of the respective elements.) [4]: The catalyst according to [3], wherein (c + d) / (b + e) ≥ 5.00 in the formula (I). [5]: The catalyst according to [3] or [4], wherein (c + d) / (b + e) = 5.40 to 10.00 in the formula (I). [6]: The catalyst according to any one of [3] to [5], wherein the X element is antimony in the formula (I). [7]: The catalyst according to any one of [1] to [6], wherein the α,β-unsaturated aldehyde is methacrolein and the α,β-unsaturated carboxylic acid is methacrylic acid. [8]: A method for producing the catalyst according to any one of [1] to [7], comprising the following steps (i) to (iii). (i) A step of preparing a slurry (Slurry C) by mixing a solution or slurry containing molybdenum and bismuth (Liquid A) with a solution or slurry containing cobalt (Liquid B). (ii) A step of preparing a slurry (Slurry D) by subjecting the Slurry C to dispersion treatment. (iii) A step of drying the Slurry D to obtain a dried product. [9]: The method for producing a catalyst according to [8], wherein in the step (ii), the Slurry C is circulated for 5 minutes to 10 hours during the dispersion treatment of the Slurry C.

[10] : The method for producing a catalyst according to [9], wherein in the step (ii), the Slurry C is circulated using a circulation pump.

[11] : The method for producing a catalyst according to any one of [8] to

[10] , wherein in the step (ii), after the dispersion treatment, the mixture is held with stirring at 60 °C or higher for 20 minutes or longer to prepare the Slurry D.

[12] : A method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid, comprising a step of oxidizing a hydrocarbon in the presence of a catalyst according to any one of [1] to [7].

[13] : A method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid, comprising a step of oxidizing a hydrocarbon in the presence of a catalyst produced by the method according to any one of [8] to

[11] .

[14] : A method for producing an α,β-unsaturated carboxylic acid, comprising a step of oxidizing an α,β-unsaturated aldehyde produced by the method according to

[12] .

[15] : A method for producing an α,β-unsaturated carboxylic acid, comprising a step of oxidizing an α,β-unsaturated aldehyde produced by the method according to

[13] .

[16] : A method for producing an α,β-unsaturated carboxylic acid ester, comprising a step of esterifying an α,β-unsaturated carboxylic acid produced by the production method according to

[14] .

[17] : A method for producing an α,β-unsaturated carboxylic acid ester, comprising a step of esterifying an α,β-unsaturated carboxylic acid produced by the production method according to

[15] .

[18] : A method for producing an α,β-unsaturated carboxylic acid ester, comprising a step of oxidative esterification of an α,β-unsaturated aldehyde produced by the production method according to

[12] .

[19] : A method for producing an α,β-unsaturated carboxylic acid ester, comprising a step of oxidative esterification of an α,β-unsaturated aldehyde produced by the production method described in

[13] .

Advantages of the Invention

[0008] According to the present invention, a catalyst capable of producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid with high selectivity can be provided. Further, according to the present invention, a method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid using this catalyst, and a method for producing an α,β-unsaturated carboxylic acid ester using the same can be provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0010] Hereinafter, embodiments according to the present invention will be described, but the present invention is not limited thereto. In this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value, and "A~B" means A or more and B or less.

[0011] [Catalyst] The catalyst according to an embodiment of the present invention is a catalyst used for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid corresponding to the hydrocarbon by an oxidation reaction of the hydrocarbon, and contains molybdenum, bismuth, and cobalt. Further, the catalyst according to an embodiment of the present invention has, in the IR spectrum, a maximum absorbance A1 in the range of wave numbers 935 to 950 cm -1 (absorption band 1), and a wave number of 830 to 880 cm -1When the maximum absorbance in the range (absorption band 2) is A2, A2 / A1 is less than 0.85. Here, the IR spectrum is subjected to baseline processing with the minimum absorbance in the range of wave numbers 1000 to 1300 cm -1 as the background.

[0012] By using the catalyst described above, α,β-unsaturated aldehydes and / or unsaturated carboxylic acids can be produced with high selectivity. The catalyst according to the embodiment of the present invention is particularly useful as a catalyst used in the production of methacrolein and / or methacrylic acid. In addition, in this specification, the expression “α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids” can be paraphrased as “at least one selected from the group consisting of α,β-unsaturated aldehydes and α,β-unsaturated carboxylic acids”.

[0013] <IR spectrum of the catalyst> The catalyst according to the embodiment of the present invention, in the IR spectrum, has a maximum absorbance A1 in the range of wave numbers 935 to 950 cm -1 and a maximum absorbance A2 in the range of wave numbers 830 to 880 cm -1 When the absorption band 2), A2 / A1 is less than 0.85. By using such a catalyst, α,β-unsaturated aldehydes and / or unsaturated carboxylic acids can be produced with high selectivity. Regarding the reason for this, the present inventors speculate as follows.

[0014] In the IR spectrum, in the range of wave numbers 935 to 950 cm -1 absorptions derived from the Mo-O stretching vibration of an oxide phase containing cobalt and molybdenum (hereinafter, also referred to as “Co-Mo oxide phase”) appear. Also, in the range of wave numbers 830 to 880 cm -1In the range, absorption derived from the Mo-O stretching vibration of an oxide phase containing bismuth and molybdenum (hereinafter also referred to as "Bi-Mo oxide phase") appears. Here, the Bi-Mo oxide phase is considered to function as an active site in the oxidation reaction of hydrocarbons. On the other hand, the Co-Mo oxide phase is considered to facilitate the transfer of oxygen species as a carrier of the Bi-Mo oxide phase and promote the re-oxidation of the active site. When A2 / A1 is equal to or less than a specified value, that is, when the Co-Mo oxide phase exists in a proportion equal to or more than a specified ratio with respect to the Bi-Mo oxide phase, the oxidation state of the Bi-Mo oxide phase is maintained in a state favorable for the selective oxidation reaction to α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid, and the selectivity is considered to be improved.

[0015] The upper limit of A2 / A1 is preferably 0.70 or less, more preferably 0.65 or less. The lower limit is preferably 0.10 or more, more preferably 0.20 or more. In the present invention, it is assumed that the IR spectrum was measured by the transmission method. For the measurement, for example, NICOLET 6700 FT-IR (manufactured by Thermo electron) etc. can be used. The measurement range is set to include a wave number of 800 to 1300 cm -1 and the measurement is carried out with 64 scans and a data interval of 0.482 cm -1 The catalyst to be measured is diluted with KBr powder and pressed firmly with a press to form a disk shape. For the press, an MP-1 type mini press, an MT-1 type micro tablet molding machine (manufactured by JASCO) etc. can be used. Here, when the absorbance increases, the S / N (ratio of detection signal to noise) decreases and the measurement accuracy deteriorates. Therefore, the amount of the catalyst is adjusted so that the maximum absorbance is 1 or less and diluted with KBr powder. Regarding the obtained IR spectrum, baseline processing is performed using the minimum absorbance in the range of a wave number of 1000 to 1300 cm -1 as the background to obtain A1 and A2.

[0016] As a method for obtaining a catalyst in which A2 / A1 satisfies the above, for example, a method of manufacturing a catalyst having a composition represented by formula (I) described later by a method including steps (i) to (iii) described later can be mentioned.

[0017] <Composition of the catalyst> As described above, the catalyst according to the embodiment of the present invention contains molybdenum, bismuth, and cobalt. From the viewpoint of improving the selectivity of the target product, the ratio of the number of bismuth atoms when the number of molybdenum atoms is 12 is preferably 0.01 to 3.00. The lower limit of the ratio of the number of bismuth atoms is more preferably 0.03 or more, and even more preferably 0.05 or more. The upper limit is more preferably 2.00 or less, and particularly preferably 1.00 or less. From the same viewpoint, the ratio of the number of cobalt atoms when the number of molybdenum atoms is 12 is preferably 1.00 to 12.00. The lower limit of the ratio of the number of cobalt atoms is preferably 2.00 or more, and even more preferably 3.00 or more. The upper limit is preferably 11.00 or less, and even more preferably 10.00 or less.

[0018] As other elements, for example, iron, silicon, oxygen, nickel, calcium, magnesium, niobium, tungsten, antimony, phosphorus, titanium, cesium, lithium, sodium, potassium, rubidium, or thallium may be included. From the viewpoint of improving the selectivity of the target product, it is preferable to contain iron and antimony, and it is also preferable to contain at least one element selected from the group consisting of cesium, lithium, sodium, potassium, rubidium, and thallium.

[0019] The catalyst according to the embodiment of the present invention may also have a carrier for supporting the above elements. There is no particular limitation on the carrier, and examples thereof include silica, alumina, silica-alumina, magnesia, titania, or silicon carbide. Among these, silica is preferable in order to prevent the reaction of the carrier itself. In the present specification, when a carrier is used for the catalyst, the carrier is also regarded as part of the catalyst.

[0020] From the viewpoint of improving the selectivity of the target product, the catalyst according to the embodiment of the present invention preferably has a composition represented by the following formula (I). The catalyst may contain a small amount of elements not described in the following formula (I). Mo a Bi b Fe c Cо d X e Y f Si g O h ···(I) In formula (I), Mo, Bi, Fe, Cо, Si and O represent molybdenum, bismuth, iron, cobalt, silicon and oxygen, respectively. X represents at least one element selected from the group consisting of nickel, calcium, magnesium, niobium, tungsten, antimony, phosphorus and titanium, and is preferably antimony. Y represents at least one element selected from the group consisting of cesium, lithium, sodium, potassium, rubidium and thallium. a, b, c, d, e, f, g and h represent the atomic ratios of the respective elements, a = 12, b = 0.01 to 3.00, c = 0 to 5.00, d = 1.00 to 12.00, e = 0 to 8.00, f = 0.001 to 2.00, g = 0 to 20.00, and h is the oxygen atomic ratio required to satisfy the valences of the respective components.

[0021] In the formula (I), from the viewpoint of improving the selectivity of the target product, b, c, d, e, f, and g preferably satisfy the following conditions. The lower limit of b is preferably 0.03 or more, more preferably 0.05 or more. The upper limit of b is preferably 2.00 or less, more preferably 1.00 or less. The lower limit of c is preferably 0.01 or more, more preferably 0.10 or more, and even more preferably 0.50 or more. The upper limit of c is preferably 4.50 or less, more preferably 4.00 or less, and even more preferably 3.50 or less. The lower limit of d is preferably 2.00 or more, more preferably 3.00 or more. The upper limit of d is preferably 11.00 or less, more preferably 10.00 or less. The lower limit of e is preferably 0.10 or more, more preferably 0.20 or more, and even more preferably 0.50 or more. The upper limit of e is more preferably 6.00 or less, and even more preferably 4.00 or less.

[0022] In the formula (I), the lower limit of (c + d) / (b + e) is preferably 5.00 or more, more preferably 5.40 or more, even more preferably 5.50 or more, and particularly preferably 5.60 or more. The upper limit of (c + d) / (b + e) is preferably 10 or less, more preferably 9.00 or less, even more preferably 8.00 or less, and particularly preferably 7.50 or less. Here, (c + d), that is, the composition ratio of iron and cobalt, is considered to contribute to the formation of the Co-Mo oxide phase. Also, (b + e), that is, the composition ratio of bismuth and the X element, is considered to contribute to the formation of the Bi-Mo oxide phase. By controlling (c + d) / (b + e) within the above range, these oxide phases are formed in a suitable ratio, and a catalyst satisfying specific conditions in the IR spectrum can be easily obtained.

[0023] The lower limit of f is preferably 0.05 or more, more preferably 0.10 or more, and even more preferably 0.20 or more. The upper limit of f is preferably 1.80 or less, more preferably 1.60 or less, and even more preferably 1.40 or less. The upper limit of g is preferably 15.00 or less, more preferably 10.00 or less. The atomic ratio of each element in this specification is the value obtained by analyzing the components obtained by dissolving the catalyst in hydrochloric acid by ICP emission spectrometry.

[0024] [Method for Producing Catalyst] The catalyst according to the above embodiment contains molybdenum, bismuth, and cobalt. In the IR spectrum, if A2 / A1 is less than 0.85, it can be produced according to the known catalyst production method. However, it is preferable that the catalyst is produced by a method including the following steps (i) to (iii), which is a catalyst production method according to another embodiment of the present invention. (i) A step of preparing a slurry (C liquid) by mixing a solution or slurry containing molybdenum and bismuth (A liquid) and a solution or slurry containing cobalt (B liquid). (ii) A step of subjecting the slurry (C liquid) to a dispersion treatment to prepare a slurry (D liquid). (iii) A step of drying the D liquid to obtain a dried product. The catalyst production method according to the present invention may further include a firing step and a forming step described later. Hereinafter, each step will be described in detail.

[0025] <Step (i)> In step (i), a slurry (C liquid) is prepared by mixing a solution or slurry containing molybdenum and bismuth (A liquid) and a solution or slurry containing cobalt (B liquid). The A liquid is prepared by mixing a raw material compound of molybdenum and bismuth with a solvent. Further, it is preferable to further mix the raw material compounds of the X element and the Y element in the formula (I).

[0026] The amount of the raw material compound used in the A liquid may be appropriately adjusted so as to obtain a desired catalyst composition. The amount of the solvent used in the A liquid is not particularly limited, but it is preferably 70 to 400 parts by mass with respect to 100 parts by mass in total of the raw material compounds.

[0027] The B liquid is prepared by mixing a raw material compound of cobalt with a solvent. Further, it is preferable to further mix a raw material compound of iron. The amount of the raw material compound used in the B liquid may be appropriately adjusted so as to obtain a desired catalyst composition. The amount of the solvent used in the liquid B is not particularly limited, but it is preferably 30 to 230 parts by mass with respect to 100 parts by mass of the total raw material compounds.

[0028] There is no particular limitation on each raw material compound, but oxides, chlorides, hydroxides, sulfates, nitrates, carbonates, ammonium salts, acetates or mixtures thereof of each element are used. Examples of the molybdenum raw material include ammonium paramolybdate, molybdenum trioxide, or molybdenum chloride, etc., and ammonium paramolybdate is preferred. Examples of the bismuth raw material include bismuth nitrate, bismuth oxide, or basic bismuth carbonate, etc., and bismuth oxide is preferred. Examples of the cobalt raw material include cobalt nitrate, cobalt hydroxide, cobalt oxide, or cobalt chloride, etc., and cobalt nitrate is preferred. The raw material compounds may be used alone or in combination of two or more.

[0029] The solvent preferably contains water, and more preferably 50 mass% or more of the whole solvent is water. The solvent may also contain an organic solvent such as alcohol or acetone. By mixing the above liquid A and liquid B, a slurry (liquid C) can be prepared.

[0030] <Step (ii)> In step (ii), the slurry (liquid C) obtained in the above step (i) is dispersed to prepare a slurry (liquid D). By dispersing the liquid C and uniformly dispersing the solid content in the liquid C, cobalt and bismuth contained in the raw material compounds can efficiently form a Co-Mo oxide phase and a Bi-Mo oxide phase, so that a catalyst satisfying specific conditions in the IR spectrum can be easily obtained.

[0031] Examples of the method for dispersing the liquid C include a method of treating the liquid C in a container using a homogenizer such as a high-pressure type, ultrasonic type, or stirring type, and it is preferable to use a stirring type homogenizer.

[0032] When performing the dispersion treatment of Liquid C, it is preferable to circulate Liquid C for 5 minutes to 10 hours. This allows the solid content in Liquid C to be more uniformly dispersed. Note that "circulation" means the operation of discharging Liquid C outside the container and then returning it to the container again.

[0033] The lower limit of the time for performing the dispersion treatment is preferably 10 minutes or more, more preferably 30 minutes or more, and even more preferably 60 minutes or more. Also, the upper limit of said time is preferably 9 hours or less, more preferably 8 hours or less, and even more preferably 7 hours or less.

[0034] The dispersion treatment is preferably performed with the temperature of Liquid C being 20 to 90°C. From the viewpoint of efficiently and uniformly dispersing the solid content in Liquid C, it is preferable to use a circulation pump for the circulation of Liquid C. As the circulation pump, a centrifugal pump, an axial flow pump, a mixed flow pump, or a positive displacement pump, etc. can be used.

[0035] After the dispersion treatment of Liquid C, it is preferable to prepare Liquid D by holding the obtained slurry at 60°C or higher with stirring for 20 minutes or more. This further promotes the formation of particles containing the generated Co-Mo oxide phase and Bi-Mo oxide phase. The lower limit of the holding temperature is preferably 70°C or higher, more preferably 80°C or higher. Also, the upper limit of the holding temperature is below the boiling point of the solvent, preferably 150°C or lower, more preferably 130°C or lower. The lower limit of the holding time is preferably 30 minutes or more, more preferably 40 minutes or more. Also, the upper limit of the holding time is preferably 4 hours or less, more preferably 2 hours or less. Also, as the method of stirring the slurry, a method using a rotary vane stirrer or a magnetic stirrer is preferable.

[0036] <Step (iii)> In step (iii), the Liquid D obtained in the above step (ii) is dried to obtain a dried product. There is no particular limitation on the method for drying D solution, and examples thereof include a method of drying using a box dryer, a method of drying using a spray dryer, a method of drying using a slurry dryer, a method of drying using a drum dryer, and a method of pulverizing the lumpy solid obtained by evaporation to dryness. There is no particular limitation on the drying conditions, and for example, when using a box dryer, it is preferable to dry at a temperature of 30 to 150°C. When using a spray dryer, it is preferable to set the inlet temperature to 100 to 500°C and the outlet temperature to 100 to 300°C.

[0037] The dried product obtained in step (iii) exhibits catalytic performance and can be used as a catalyst, but it is preferable to further perform calcination or molding as described below in order to improve the performance as a catalyst. In the embodiment of the present invention, the calcined and molded products are collectively referred to as catalysts.

[0038] <Firing process> The dried product obtained in the step (iii) may contain salts such as nitric acid derived from the raw material compounds, etc. Therefore, it is preferable to calcinate the dried product to remove such salts and obtain a calcined product.

[0039] The calcination can be performed after the molding step described later is performed to obtain a molded product, but from the viewpoint of catalyst strength, it is preferable to perform the calcination before the molding step. The calcination may be performed only once, or may be performed multiple times in combination with the molding step described later. It is preferable to first perform a primary calcination of the dried product in order to remove salts, and then perform a molding step described later, followed by a secondary calcination to form the final catalytic active site structure. Alternatively, the primary and secondary calcinations may be performed, followed by the molding step.

[0040] The calcination is preferably carried out under a flow of an oxygen-containing gas such as air, or under a flow of an inert gas such as nitrogen, carbon dioxide, helium, or argon. From the viewpoint of the selectivity of the resulting catalyst, the calcination temperature is preferably from 200 to 700°C, and more preferably the lower limit is 250°C or higher and the upper limit is 600°C or lower. The firing time is appropriately selected according to the target catalyst. From the perspective of the selectivity of the resulting catalyst, 10 minutes to 10 hours is preferable, the lower limit is more preferably 1 hour or more, the upper limit is more preferably 7 hours or less, and even more preferably 6 hours or less. Note that the firing time means the time for which firing is continued after reaching a predetermined firing temperature.

[0041] When performing the first firing of the dried product and then performing the second firing after carrying out the shaping process described later, the firing temperature of the first firing is preferably 200 to 600°C. The lower limit of the firing temperature of the first firing is more preferably 250°C or higher, and the upper limit is more preferably 450°C or lower. The firing time of the first firing is preferably 0.5 to 5 hours.

[0042] For the first firing, for example, a box-type firing furnace, a tunnel furnace-type firing furnace, etc. may be used to fire the dried product in a fixed state, or a rotary kiln, etc. may be used to fire the dried product while it is being fluidized.

[0043] The firing temperature of the second firing is preferably 300 to 700°C. The lower limit of the firing temperature of the second firing is more preferably 400°C or higher, and the upper limit is more preferably 600°C or lower. The firing time of the second firing is preferably 10 minutes to 10 hours, the lower limit is more preferably 1 hour or more, the upper limit is more preferably 7 hours or less, and even more preferably 6 hours or less.

[0044] For the second firing, for example, a box-type firing furnace, or a firing furnace such as a tunnel furnace-type firing furnace may be used to fire the shaped product or the first-fired product in a fixed state, or a rotary kiln, etc. may be used to fire the shaped product while it is being fluidized.

[0045] <Shaping process> In the shaping process, the dried product before or after firing is shaped to obtain a shaped product. There are no particular restrictions on the shaping method, and general powder shaping machines such as a tableting machine, an extrusion molding machine, or a rolling granulator can be used.

[0046] During forming, conventionally known additives may be added to the dried product before or after firing. Examples of the additives include organic compounds such as polyvinyl alcohol and carboxymethyl cellulose, inorganic compounds such as graphite and diatomaceous earth, and inorganic fibers such as glass fiber, ceramic fiber, and carbon fiber.

[0047] Examples of the shape of the formed product include any shape such as spherical, cylindrical, ring-shaped, star-shaped, and granular after being pulverized and classified after forming. The outer diameter of the formed product is preferably 0.01 to 2 cm after firing. When the outer diameter is 0.01 cm or more, α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid can be stably produced over a long period. Also, when the outer diameter is 2 cm or less, the strength of the formed product can be maintained. The lower limit of the outer diameter is more preferably 0.05 cm or more, and even more preferably 0.1 cm or more. The upper limit of the outer diameter is more preferably 1.5 cm or less, and even more preferably 1 cm or less.

[0048] The outer surface area of the formed product is preferably 0.01 to 4 cm 2 after firing. When the outer surface area is 0.01 cm 2 or more, α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid can be stably produced over a long period. Also, when the outer surface area is 4 cm 2 or less, the selectivity of α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid is improved. The lower limit of the outer surface area is more preferably 0.05 cm 2 or more, and even more preferably 0.1 cm 2 or more. The upper limit of the outer surface area is more preferably 3 cm 2 or less, and even more preferably 2 cm 2 or less.

[0049] The volume of the formed product is preferably 0.0002 to 5 cm 3 after firing. When the volume is 0.0002 cm 3By being as described above, α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid can be stably produced over a long period. Also, the volume is 5 cm 3 By being as described below, the selectivity of α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid is improved. The lower limit of the volume is 0.002 cm 3 It is more preferable to be above, and 0.02 cm 3 It is even more preferable to be above. Also, the upper limit of the volume is 1 cm 3 It is more preferable to be below, and 0.5 cm 3 It is even more preferable to be below.

[0050] The mass of the molded article is preferably 0.002 to 0.5 g / piece after firing. By the mass being 0.002 g / piece or more, α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid can be stably produced over a long period. Also, by the mass being 0.5 g / piece or less, the selectivity of α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid is improved. The lower limit of the mass is more preferably 0.01 g / piece or more, and even more preferably 0.05 g / piece or more. Also, the upper limit of the mass is more preferably 0.3 g / piece or less, and even more preferably 0.2 g / piece or less.

[0051] The bulk density of the molded article is preferably 0.2 to 1 g / cm 3 after firing. By the bulk density being 0.2 g / cm 3 or more, α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid can be stably produced over a long period. Also, by the bulk density being 1 g / cm 3 or less, the selectivity of α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid is improved. The lower limit of the bulk density is more preferably 0.3 g / cm 3 or more, and even more preferably 0.4 g / cm 3 or more. Also, the upper limit of the bulk density is more preferably 0.9 g / cm 3 or less, and even more preferably 0.8 g / cm 3The following is more preferable. The bulk density of the molded product shall mean a value calculated from the total mass of the molded product when the molded product is filled in a 100 mL graduated cylinder by a method conforming to JIS-K 7365.

[0052] The obtained molded product may be supported on a carrier. Examples of the carrier used for the support include inert substances such as silica, alumina, silica-alumina, magnesia, titania, or silicon carbide. The molded product can also be diluted with these inert substances before use.

[0053] [Process for producing α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid] The process for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid according to another embodiment of the present invention includes a step of oxidizing a hydrocarbon in the presence of the catalyst described above, and by this oxidation, a corresponding α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid is produced. Further, the process for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid according to still another embodiment includes a step of oxidizing a hydrocarbon in the presence of the catalyst produced by the above method, and by this oxidation, a corresponding α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid is produced. According to this method, an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid can be obtained with high selectivity.

[0054] As the hydrocarbon, specifically, raw material organic compounds such as propylene, isobutylene, TBA or MTBE can be used. Note that the α,β-unsaturated aldehyde corresponding to propylene is acrolein, and the α,β-unsaturated carboxylic acid corresponding to propylene is acrylic acid. The α,β-unsaturated aldehyde corresponding to isobutylene is methacrolein, and the α,β-unsaturated carboxylic acid corresponding to isobutylene is methacrylic acid. The α,β-unsaturated aldehyde corresponding to TBA is methacrolein, and the α,β-unsaturated carboxylic acid corresponding to TBA is methacrylic acid. The α,β-unsaturated aldehyde corresponding to MTBE is methacrolein, and the α,β-unsaturated carboxylic acid corresponding to MTBE is methacrylic acid. From the viewpoint of improving the selectivity of the product, the α,β-unsaturated aldehyde and the α,β-unsaturated carboxylic acid are preferably methacrolein and methacrylic acid, respectively.

[0055] The method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid according to an embodiment of the present invention can be carried out by bringing the above-described catalyst into contact with a raw material gas containing a hydrocarbon and oxygen in a reactor. As the reactor, those generally used for gas-phase oxidation can be used, and it is preferable to use a tubular reactor equipped with a reaction tube filled with a catalyst. Industrially, it is preferable to use a multi-tubular reactor equipped with a plurality of the reaction tubes.

[0056] The hydrocarbon concentration in the raw material gas is not particularly limited, but is preferably 1 to 20% by volume, more preferably 3% by volume or more as the lower limit and 10% by volume or less as the upper limit. As the oxygen source of the raw material gas, there is no particular limitation, but it is industrially advantageous to use air. Further, if necessary, a gas in which pure oxygen is mixed with air or the like can also be used. The ratio of oxygen in the raw material gas is not particularly limited, but is preferably 10 to 500% by volume with respect to the hydrocarbon, more preferably 50% by volume or more as the lower limit and 300% by volume or less as the upper limit. From an economic perspective, it is preferable to use the raw material gas diluted with an inert gas such as nitrogen gas or carbon dioxide gas, or water vapor.

[0057] There is no particular limitation on the contact time between the raw material gas and the catalyst, but it is preferably 0.5 to 10 seconds, more preferably at least 1 second and at most 5 seconds for the lower and upper limits, respectively. The pressure during the oxidation reaction is usually about atmospheric pressure to several atmospheres. The temperature during the oxidation reaction is preferably 200 to 450 °C, more preferably at least 250 °C and at most 400 °C for the lower and upper limits, respectively.

[0058] [Method for producing α,β-unsaturated carboxylic acid] The method for producing an α,β-unsaturated carboxylic acid according to another embodiment of the present invention includes a step of oxidizing the α,β-unsaturated aldehyde produced by the method described above, and by this oxidation, a method for producing the corresponding α,β-unsaturated carboxylic acid. From the viewpoint of improving the selectivity of the product, the α,β-unsaturated aldehyde and the α,β-unsaturated carboxylic acid are preferably methacrolein and methacrylic acid, respectively.

[0059] The method for producing an α,β-unsaturated carboxylic acid according to an embodiment of the present invention can be carried out by bringing a catalyst for producing an α,β-unsaturated carboxylic acid into contact with a raw material gas containing an α,β-unsaturated aldehyde in a reactor. As the catalyst, it is preferable to use a heteropolyacid catalyst. As the reactor, the same reactor as the method for producing the α,β-unsaturated aldehyde described above can be used.

[0060] There is no particular limitation on the concentration of the α,β-unsaturated aldehyde in the raw material gas, but it is preferably 1 to 20% by volume, more preferably at least 3% by volume and at most 10% by volume for the lower and upper limits, respectively. As the oxygen source of the raw material gas, there are no particular restrictions, but it is industrially advantageous to use air. Further, if necessary, a gas in which pure oxygen is mixed with air or the like can also be used. The proportion of oxygen in the raw material gas is not particularly limited, but is preferably 40 to 400% by volume with respect to the α,β-unsaturated aldehyde, more preferably 50% by volume or more as the lower limit and 300% by volume or less as the upper limit. From an economic point of view, the raw material gas is preferably diluted with an inert gas such as nitrogen gas or carbon dioxide gas, or water vapor and used.

[0061] The contact time between the raw material gas and the catalyst for producing the α,β-unsaturated carboxylic acid is not particularly limited, but is preferably 1.5 to 15 seconds. The pressure during the oxidation reaction is usually from atmospheric pressure to about several atmospheres. The temperature during the oxidation reaction is preferably 200 to 400 °C, and more preferably 250 °C or higher as the lower limit.

[0062] [Method for producing α,β-unsaturated carboxylic acid ester] The method for producing an α,β-unsaturated carboxylic acid ester according to another embodiment of the present invention includes a step of esterifying the α,β-unsaturated carboxylic acid produced by the method described above, and by this esterification, a method for producing an α,β-unsaturated carboxylic acid ester.

[0063] The alcohol to be reacted with the α,β-unsaturated carboxylic acid is not particularly limited, and examples thereof include methanol, ethanol, propanol, isopropanol, butanol, isobutanol and the like. Examples of the obtained α,β-unsaturated carboxylic acid ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate and the like.

[0064] The esterification reaction can be carried out in the presence of an acidic catalyst such as a sulfonic acid type cation exchange resin. The temperature during the esterification reaction is preferably 50 to 200 °C.

[0065] The method for producing an α,β-unsaturated carboxylic acid ester according to still another embodiment of the present invention includes a step of oxidative esterification of the α,β-unsaturated aldehyde produced by the method described above, and by this oxidative esterification, an α,β-unsaturated carboxylic acid ester is produced. However, "oxidative esterification" means oxidizing and then esterifying. In addition, regarding the oxidative esterification of an α,β-unsaturated aldehyde, that is, a method of oxidizing an α,β-unsaturated aldehyde and further esterifying the α,β-unsaturated carboxylic acid generated by the oxidation, the methods described in the above [Method for producing α,β-unsaturated carboxylic acid] and [Method for producing α,β-unsaturated carboxylic acid ester] can be adopted.

Examples

[0066] Hereinafter, a production example of a catalyst according to an embodiment of the present invention and a reaction example using the same will be described together with comparative examples.

[0067] (Composition ratio of catalyst) The composition of each element was determined by analyzing the components obtained by dissolving the catalyst in hydrochloric acid by ICP emission spectrometry.

[0068] (Measurement of IR spectrum of catalyst) The IR spectrum of the catalyst was measured by the transmission method using NICOLET 6700 (manufactured by Thermo electron). Using a DTGS detector, the measurement range was a wave number of 400 to 4000 cm -1 , the number of scans was 64 times, and the data interval was 0.482 cm -1 . As the measurement sample, 0.5 mg of the catalyst was mixed with 100 mg of KBr powder and diluted, and 15 mg of the obtained dilution was pressed by a press to form a disk with φ = 5 mm and used.

[0069] (Reaction evaluation) The reaction evaluations of the catalysts in the examples and comparative examples were carried out using the production of methacrolein and methacrylic acid by the oxidation of isobutylene as an example. The analysis in the reaction evaluation was performed by gas chromatography (apparatus: GC-2014 manufactured by Shimadzu Corporation, column: DB-FFAP manufactured by J&W, 30 m × 0.32 mm, film thickness 0.25 μm). From the results of gas chromatography, the selectivities of the produced methacrolein and methacrylic acid were calculated by the following formula. Total selectivity of methacrolein and methacrylic acid (%) = ((number of moles of produced methacrolein + number of moles of produced methacrylic acid) / number of moles of reacted isobutylene) × 100

[0070] <Example 1> To 200 parts by mass of pure water at room temperature, 50.4 parts by mass of ammonium paramolybdate tetrahydrate, 3.3 parts by mass of bismuth oxide and 3.5 parts by mass of antimony trioxide were mixed and heated to 60 °C. Then, a solution prepared by mixing 2.3 parts by mass of cesium nitrate with 20.7 parts by mass of pure water was added to obtain Solution A. Also, 23.1 parts by mass of iron(III) nitrate nonahydrate and 55.4 parts by mass of cobalt(II) nitrate hexahydrate were mixed in 100 parts by mass of pure water at room temperature to prepare Solution B. Next, Solution A and Solution B were mixed to prepare Solution C. While circulating the obtained Solution C using a circulation pump, dispersion treatment was carried out for 90 minutes using a stirring homogenizer. Subsequently, the slurry after the dispersion treatment was heated to 95 °C and held for 1 hour with stirring using a rotary vane stirrer to prepare Solution D. The obtained Solution D was evaporated to dryness at 130 °C to obtain a dried product. The obtained dried product was calcined for 1 hour at 300 °C in an air atmosphere for the first time. Then, the dried product after the first calcination was calcined for 6 hours at 500 °C in an air atmosphere for the second time to obtain a catalyst. The composition of the catalyst excluding oxygen was Mo 12 Bi 0.60 Fe 2.40 Co 8.00 Sb 1.00 Cs 0.50 It was. Also, for the said catalyst, the IR spectrum was measured. The obtained value of A2 / A1 is shown in Table 1, and the IR spectrum is shown in Fig. 1. The obtained catalyst was filled into a stainless steel reaction tube, and a raw material gas composed of 5% by volume of isobutylene, 12% by volume of oxygen, 10% by volume of steam, and 73% by volume of nitrogen was passed through the catalyst in the reaction tube with a contact time of 0.18 seconds, and the reaction evaluation was carried out at a temperature of 330°C. The obtained results are shown in Table 1.

[0071] <Example 2> A catalyst was prepared in the same manner as in Example 1, except that 5.0 parts by mass of bismuth oxide, 2.4 parts by mass of antimony trioxide, and 62.3 parts by mass of cobalt(II) nitrate hexahydrate were used. The composition of the elements excluding oxygen in the catalyst was Mo 12 Bi 0.90 Fe 2.40 Co 9.00 Sb 0.70 Cs 0.50 The IR spectrum of the catalyst was measured. The obtained A2 / A1 value is shown in Table 1, and the IR spectrum is shown in Figure 2. Using the obtained catalyst, the reaction evaluation was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

[0072] <Example 3> A catalyst was prepared in the same manner as in Example 1, except that 5.0 parts by mass of bismuth oxide, 2.4 parts by mass of antimony trioxide, and 17.3 parts by mass of iron(III) nitrate nonahydrate were used. The composition of the elements excluding oxygen in the catalyst was Mo 12 Bi 0.90 Fe 1.80 Co 8.00 Sb 0.70 Cs 0.50 The IR spectrum of the catalyst was measured. The obtained A2 / A1 value is shown in Table 1. Using the obtained catalyst, the reaction evaluation was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

[0073] <Example 4> A catalyst was prepared in the same manner as in Example 1, except that 1.7 parts by mass of bismuth oxide, 17.3 parts by mass of iron(III) nitrate nonahydrate, and 48.5 parts by mass of cobalt(II) nitrate hexahydrate were used. The composition of the elements excluding oxygen in the catalyst was Mo12 Bi 0.30 Fe 1.80 Co 7.00 Sb 1.00 Cs 0.50 It was. Also, the IR spectrum of the catalyst was measured. The obtained A2 / A1 values are shown in Table 1. Using the obtained catalyst, reaction evaluation was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

[0074] <Example 5> A catalyst was prepared in the same manner as in Example 1, except that 1.7 parts by mass of bismuth oxide, 4.5 parts by mass of antimony trioxide, and 28.8 parts by mass of iron(III) nitrate nonahydrate were used. The composition of the elements excluding oxygen in the catalyst was Mo 12 Bi 0.30 Fe 3.00 Co 8.00 Sb 1.30 Cs 0.50 It was. Also, the IR spectrum of the catalyst was measured. The obtained A2 / A1 values are shown in Table 1. Using the obtained catalyst, reaction evaluation was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

[0075] <Example 6> A catalyst was prepared in the same manner as in Example 1, except that 4.5 parts by mass of antimony trioxide and 28.8 parts by mass of iron(III) nitrate nonahydrate were used. The composition of the elements excluding oxygen in the catalyst was Mo 12 Bi 0.60 Fe 3.00 Co 8.00 Sb 1.30 Cs 0.50 It was. Also, the IR spectrum of the catalyst was measured. The obtained A2 / A1 values are shown in Table 1. Using the obtained catalyst, reaction evaluation was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

[0076] <Example 7> A catalyst was prepared in the same manner as in Example 1, except that 5.0 parts by mass of bismuth oxide, 17.3 parts by mass of iron(III) nitrate nonahydrate, and 62.3 parts by mass of cobalt(II) nitrate hexahydrate were used. The composition of the elements excluding oxygen in the catalyst was Mo 12 Bi 0.90 Fe 1.80 Co 9.00 Sb 1.00 Cs 0.50 It was. Also, the IR spectrum of the catalyst was measured. The obtained value of A2 / A1 is shown in Table 1. Using the obtained catalyst, reaction evaluation was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

[0077] <Example 8> A catalyst was prepared in the same manner as in Example 1, except that 5.0 parts by mass of bismuth oxide, 2.4 parts by mass of antimony trioxide, and 17.3 parts by mass of iron(III) nitrate nonahydrate were used. The composition of the elements excluding oxygen in the catalyst was Mo 12 Bi 0.90 Fe 1.80 Co 8.00 Sb 0.70 Cs 0.50 It was. Also, the IR spectrum of the catalyst was measured. The obtained value of A2 / A1 is shown in Table 1. Using the obtained catalyst, measurement of the IR spectrum was carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

[0078] <Comparative Example 1> A catalyst was prepared in the same manner as in Example 1, except that 5.0 parts by mass of bismuth oxide, 4.5 parts by mass of antimony trioxide, and 28.8 parts by mass of iron(III) nitrate nonahydrate were used. The composition of the elements excluding oxygen in the catalyst was Mo 12 Bi 0.90 Fe 3.00 Co 8.00 Sb 1.30 Cs 0.50 It was. Also, the IR spectrum of the catalyst was measured. The obtained value of A2 / A1 is shown in Table 1. Using the obtained catalyst, IR spectra were measured in the same manner as in Example 1. The obtained results are shown in Table 1.

[0079] <Comparative Example 2> A catalyst was prepared in the same manner as in Example 1, except that 4.5 parts by mass of antimony trioxide, 28.8 parts by mass of iron(III) nitrate nonahydrate, and 48.5 parts by mass of cobalt(II) nitrate hexahydrate were used. The composition of the elements excluding oxygen in the catalyst was Mo 12 Bi 0.60 Fe 3.00 Co 7.00 Sb 1.30 Cs 0.50 For this catalyst, an IR spectrum was measured. The obtained value of A2 / A1 is shown in Table 1. Using the obtained catalyst, IR spectra were measured and reaction evaluations were carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

[0080] <Comparative Example 3> A catalyst was prepared in the same manner as in Example 1, except that 5.0 parts by mass of bismuth oxide and 48.5 parts by mass of cobalt(II) nitrate hexahydrate were used. The composition of the elements excluding oxygen in the catalyst was Mo 12 Bi 0.90 Fe 2.40 Co 7.00 Sb 1.00 Cs 0.50 For this catalyst, an IR spectrum was measured. The obtained value of A2 / A1 is shown in Table 1. Using the obtained catalyst, IR spectra were measured in the same manner as in Example 1. The obtained results are shown in Table 1.

[0081]

Table 1

[0082] As shown in Table 1, in Examples 1 to 8 using catalysts whose IR spectrum absorbance satisfied the specified conditions, the total selectivity of methacrolein and methacrylic acid was better than that in Comparative Examples 1 to 3 that did not satisfy the conditions. By oxidizing the methacrolein obtained in this example, methacrylic acid can be obtained, and by esterifying methacrylic acid, a methacrylic acid ester can be obtained.

Industrial Applicability

[0083] According to the present invention, a catalyst capable of producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid with high selectivity can be provided.

Claims

1. A catalyst used in producing a corresponding α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid by an oxidation reaction of a hydrocarbon, comprising: Contains molybdenum, bismuth and cobalt, It has a composition represented by the following formula (I), in which (c+d) / (b+e)=5.40 to 9.00: In the infrared absorption spectrum of the catalyst, the wave number is 1000 to 1300 cm －１ Baseline processing was performed using the minimum absorbance in the range of wavenumber 935 to 950 cm as the background. －１ The maximum absorbance in the range of A1 and wavenumber 830 to 880 cm －１ When the maximum absorbance in the range is A2, A2 / A1 is 0.10 to 0.

70. Mo ａ Yes ｂ Fe ｃ Yes ｄ X ｅ Y ｆ Yes ｇ Oh ｈ ・・・(@) (In formula (I), Mo, Bi, Fe, Co, Si, and O represent molybdenum, bismuth, iron, cobalt, silicon, and oxygen, respectively; X represents at least one element selected from the group consisting of nickel, calcium, magnesium, niobium, tungsten, antimony, phosphorus, and titanium; Y represents at least one element selected from the group consisting of cesium, lithium, sodium, potassium, rubidium, and thallium; a, b, c, d, e, f, g, and h represent the atomic ratios of each element, where a=12, b=0.01-3.00, c=0.01-5.00, d=1.00-12.00, e=0.1-8.00, f=0.001-2.00, and g=0-20.00; and h represents the atomic ratio of oxygen necessary to satisfy the valence of each of the elements.)

2. 2. The catalyst according to claim 1, wherein in said formula (I) the X element is antimony.

3. 2. The catalyst according to claim 1, wherein the α,β-unsaturated aldehyde is methacrolein and the α,β-unsaturated carboxylic acid is methacrylic acid.

4. A method for producing the catalyst according to claim 1, comprising the following steps (i) to (iii): (i) A step of mixing a solution or slurry containing molybdenum and bismuth (Liquid A) with a solution or slurry containing cobalt (Liquid B) to prepare a slurry (Liquid C). (ii) A step of dispersing the liquid C to prepare a slurry (liquid D). (iii) A step of drying the solution D to obtain a dry product.

5. The method for producing a catalyst according to claim 4, wherein in the step (ii), the liquid C is circulated for 5 minutes to 10 hours during the dispersion treatment of the liquid C.

6. The method for producing a catalyst according to claim 5, wherein in the step (ii), the solution C is circulated using a circulation pump.

7. The method for producing a catalyst according to claim 4, wherein in the step (ii), after the dispersion treatment, the solution D is prepared by maintaining the solution at 60°C or higher for 20 minutes or longer with stirring.

8. A method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid, comprising a step of oxidizing a hydrocarbon in the presence of the catalyst according to any one of claims 1 to 3.

9. A method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid, comprising a step of oxidizing a hydrocarbon in the presence of a catalyst produced by the production method according to any one of claims 4 to 7.

10. A method for producing an α,β-unsaturated carboxylic acid, comprising a step of oxidizing the α,β-unsaturated aldehyde produced by the method according to claim 8.

11. A method for producing an α,β-unsaturated carboxylic acid, comprising a step of oxidizing the α,β-unsaturated aldehyde produced by the method according to claim 9.

12. A method for producing an α,β-unsaturated carboxylic acid ester, comprising a step of esterifying the α,β-unsaturated carboxylic acid produced by the method according to claim 10.

13. A method for producing an α,β-unsaturated carboxylic acid ester, comprising a step of esterifying the α,β-unsaturated carboxylic acid produced by the production method according to claim 11.

14. A method for producing an α,β-unsaturated carboxylic acid ester, comprising a step of oxidizing and esterifying the α,β-unsaturated aldehyde produced by the method according to claim 8.

15. A method for producing an α,β-unsaturated carboxylic acid ester, comprising a step of oxidatively esterifying the α,β-unsaturated aldehyde produced by the method according to claim 9.

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