Catalyst, method for producing catalyst, and method for producing α,β-unsaturated aldehyde, α,β-unsaturated carboxylic acid and α,β-unsaturated carboxylic acid ester

Abstract

The present invention aims to provide a catalyst for α,β-unsaturated aldehyde and α,β-unsaturated carboxylic acid, etc. with high selectivity. The problem is solved by a catalyst containing at least molybdenum and bismuth, wherein the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated from ICP (inductively coupled high frequency plasma) emission spectroscopy is A, and the ratio of the peak area of bismuth atoms to the peak area of molybdenum atoms measured by X-ray photoelectron spectroscopy is B, and B / A is 1.3 to 5.

Description

Technical Field

[0001] The present invention relates to a catalyst, a method for producing the catalyst, and a method for producing α,β-unsaturated aldehyde, α,β-unsaturated carboxylic acid and α,β-unsaturated carboxylic acid ester. Background Art

[0002] There is known a method for producing α,β-unsaturated aldehydes, α,β-unsaturated carboxylic acids, and the like by performing a gas-phase oxidation reaction using organic compounds such as propylene, isobutylene, tert-butyl alcohol, and methyl tert-butyl ether in the presence of a metal oxide catalyst.

[0003] For example, Patent Document 1 describes a method for producing a composite oxide catalyst containing at least molybdenum, bismuth, cobalt and / or nickel, and iron as a catalyst used in producing corresponding unsaturated aldehydes and unsaturated carboxylic acids from olefins.

[0004] In addition, Patent Document 2 describes an example in which a catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids having excellent catalytic activity and selectivity can be provided by being composed of particles of a composite oxide containing at least molybdenum, iron, and cobalt, wherein the atomic ratios in the bulk composition and surface composition of the particles satisfy specific conditions.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2005-169311

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2011-115681 Summary of the Invention

[0009] However, the present inventors' research has revealed that the performance of the catalysts described in Patent Documents 1 and 2 is not always sufficient, and that they sometimes produce a significant amount of byproducts. These issues can affect the selectivity of α,β-unsaturated aldehydes and α,β-unsaturated carboxylic acids, leading to a current demand for further improvement in catalyst performance. Therefore, to further enhance catalyst performance, it is necessary to control catalyst properties.

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a catalyst having a high selectivity for target products such as α,β-unsaturated aldehyde and α,β-unsaturated carboxylic acid.

[0011] The present inventors have conducted intensive studies to achieve the above-mentioned object and have found that, in a catalyst containing at least molybdenum and bismuth, the target product can be produced with high selectivity by adjusting the bismuth composition on the catalyst surface relative to the entire catalyst.

[0012] That is, the present invention includes the following aspects.

[0013] [1]: A catalyst comprising at least molybdenum and bismuth,

[0014] When the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP (inductively coupled plasma) emission spectrometry is set as A, and the ratio of the peak area of ​​bismuth atoms to the peak area of ​​molybdenum atoms measured by X-ray photoelectron spectroscopy is set as B, B / A is 1.3 to 5.

[0015] [2]: The catalyst according to [1], wherein the value of B / A is 1.5 to 4.

[0016] [3]: The catalyst according to [1] or [2], wherein the value of B / A is 1.7 to 3.

[0017] [4]: The catalyst according to any one of [1] to [3], wherein the value of A is 0.02 to 0.1.

[0018] [5]: The catalyst according to any one of [1] to [4], wherein the value of B is 0.04 to 0.2.

[0019] [6]: The catalyst according to any one of [1] to [5], wherein the value of B is 0.07 to 0.16.

[0020] [7]: The catalyst according to any one of [1] to [6], which is used in the production of α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids from olefins, alcohols, or ethers.

[0021] [8]: The catalyst according to any one of [1] to [7], wherein the catalyst composition is represented by the following formula (1).

[0022] Mo a Bi b Fe c M d X e Y f Si g O h (1)

[0023] (In the above formula (1), Mo, Bi, Fe, Si, and O represent molybdenum, bismuth, iron, silicon, and oxygen, respectively. M represents at least one element selected from cobalt and nickel. X represents at least one element selected from zinc, chromium, lead, manganese, calcium, magnesium, niobium, silver, barium, tin, tantalum, tungsten, antimony, phosphorus, boron, sulfur, selenium, tellurium, cerium, and titanium. Y represents at least one element selected from cesium, lithium, sodium, potassium, rubidium, and thallium. a, b, c, d, e, f, g, and h represent the atomic ratios of the respective elements. When a=12, b=0.01-3, c=0-8, d=0-12, e=0-8, f=0.001-2, g=0-20, and h represents the atomic ratio of oxygen required to satisfy the atomic valences of the above-mentioned components.)

[0024] [9]: A method for producing a catalyst containing at least molybdenum and bismuth, comprising the following steps (i) to (v):

[0025] (i) a step of mixing at least a molybdenum raw material and a bismuth raw material with a solvent to obtain a slurry (liquid A);

[0026] (ii) stirring the liquid A at a temperature 1 to 30° C. lower than the boiling point of the solvent for 20 to 90 minutes to obtain a slurry (liquid B);

[0027] (iii) stirring the liquid B at a temperature 2°C higher than the temperature in the step (ii) for 10 minutes to 10 hours to obtain a slurry (liquid C);

[0028] (iv) drying the liquid C to obtain a dried product, and

[0029] (v) A step of calcining the dried product to obtain a catalyst.

[0030]

[10] : The method for producing a catalyst according to [9], wherein in the step (i), 50% by mass or more of the entire solvent is water.

[0031]

[11] : The method for producing a catalyst according to [9] or

[10] , wherein the temperature in the step (iii) is 1 to 20°C higher than the boiling point of the solvent.

[0032]

[12] : The method for producing a catalyst according to any one of [9] to

[11] , wherein in the step (iii), the liquid B is stirred for 90 minutes to 10 hours to obtain the liquid C.

[0033]

[13] : The method for producing a catalyst according to any one of [9] to

[12] , wherein the method is for producing a catalyst for use in producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid from an olefin, an alcohol or an ether.

[0034]

[14] : The method for producing a catalyst according to any one of [9] to

[13] , wherein a catalyst having a composition represented by the following formula (1) is produced.

[0035] Mo a Bi b Fe c M d X e Y f Si g O h (1)

[0036] (In the above formula (1), Mo, Bi, Fe, Si, and O represent molybdenum, bismuth, iron, silicon, and oxygen, respectively; M represents at least one element selected from cobalt and nickel; X represents at least one element selected from zinc, chromium, lead, manganese, calcium, magnesium, niobium, silver, barium, tin, tantalum, tungsten, antimony, phosphorus, boron, sulfur, selenium, tellurium, cerium, and titanium; and Y represents at least one element selected from cesium, lithium, sodium, potassium, rubidium, and thallium. a, b, c, d, e, f, g, and h represent the atomic ratios of the respective elements; when a=12, b=0.01-3, c=0-8, d=0-12, e=0-8, f=0.001-2, g=0-20, and h represents the atomic ratio of oxygen required to satisfy the atomic valences of the above-mentioned components.)

[0037]

[15] : A method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid, comprising producing the α,β-unsaturated aldehyde and / or the α,β-unsaturated carboxylic acid from an olefin, an alcohol or an ether using the catalyst described in any one of [1] to [8].

[0038]

[16] : A method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid, comprising producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid from an olefin, an alcohol or an ether using a catalyst produced by the method for producing a catalyst described in any one of [9] to

[14] .

[0039]

[17] : A method for producing an α,β-unsaturated carboxylic acid, comprising producing an α,β-unsaturated carboxylic acid from an α,β-unsaturated aldehyde produced by the method described in

[15] or

[16] .

[0040]

[18] : A method for producing an α,β-unsaturated carboxylic acid ester, comprising producing an α,β-unsaturated carboxylic acid ester from an α,β-unsaturated carboxylic acid produced by the method described in any one of

[15] to

[17] .

[0041] According to the present invention, a catalyst having high selectivity for a target product can be provided. DETAILED DESCRIPTION

[0042] The following describes embodiments of the present invention, but the present invention is not limited to the following. Furthermore, unless otherwise specified, the descriptions of "XX or greater and YY or less" or "XX to YY" indicating numerical ranges indicate numerical ranges that include both the lower and upper limits as endpoints. When describing numerical ranges in sections, the upper and lower limits of each numerical range may be arbitrarily combined.

[0043] [catalyst]

[0044] The catalyst of the present invention contains at least molybdenum and bismuth. When A is the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP (inductively coupled plasma) emission spectroscopy, and B is the ratio of the peak area of ​​bismuth atoms to the peak area of ​​molybdenum atoms measured by X-ray photoelectron spectroscopy, B / A is 1.3 to 5. By using such a catalyst, the target product can be produced from the raw material with high selectivity.

[0045] From the perspective of selectivity for the target product, the catalyst of the present invention is preferably an oxidation catalyst, and more preferably a catalyst used in the production of α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids. Specifically, it is preferably a catalyst used in the production of α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids from olefins, alcohols, or ethers. It should be noted that "production of α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids" refers to the production of either or both α,β-unsaturated aldehydes and α,β-unsaturated carboxylic acids.

[0046] (Composition of Catalyst)

[0047] The catalyst of the present invention preferably contains at least molybdenum and bismuth and has a composition represented by the following formula (1). The catalyst component may contain a small amount of elements not described in the following formula (1).

[0048] Mo a Bi b Fe c M d X e Y f Si g O h (1)

[0049] In formula (1), Mo, Bi, Fe, Si, and O represent molybdenum, bismuth, iron, silicon, and oxygen, respectively. M represents at least one element selected from cobalt and nickel. X represents at least one element selected from zinc, chromium, lead, manganese, calcium, magnesium, niobium, silver, barium, tin, tantalum, tungsten, antimony, phosphorus, boron, sulfur, selenium, tellurium, cerium, and titanium. Y represents at least one element selected from cesium, lithium, sodium, potassium, rubidium, and thallium. a, b, c, d, e, f, g, and h represent the atomic ratios of the elements. When a=12, b=0.01-3, c=0-8, d=0-12, e=0-8, f=0.001-2, g=0-20, and h represents the atomic ratio of oxygen required to satisfy the atomic valences of the above components.

[0050] In the above formula (1), from the perspective of improving the selectivity of the target product, when a = 12, the lower limit of b is preferably 0.03 or greater, more preferably 0.05 or greater. Furthermore, the upper limit of b is preferably 2 or less, more preferably 1 or less. The lower limit of c is preferably 0.01 or greater, more preferably 0.1 or greater, further preferably 1 or greater, and particularly preferably 3 or greater. Furthermore, the upper limit of c is preferably 6 or less, more preferably 4 or less.

[0051] The catalyst contains molybdenum, bismuth, and iron as needed, and may contain elements other than these elements such as M, X, and Y in the above formula (1). Of the other elements, M is preferably contained, and Y is more preferably contained.

[0052] In the above formula (1), from the viewpoint of improving the selectivity of the target product, when a=12, the lower limit of d is preferably 0.01 or more, more preferably 0.1 or more, further preferably 1 or more, and particularly preferably 3 or more. In addition, the upper limit of d is preferably 10 or less, more preferably 9 or less. The lower limit of e is preferably 0.1 or more, more preferably 0.2 or more, further preferably 0.5 or more. In addition, the upper limit of e is preferably 6 or less, more preferably 4 or less. The lower limit of f is preferably 0.05 or more, more preferably 0.1 or more, further preferably 0.2 or more. In addition, the upper limit is preferably 1.8 or less, more preferably 1.6 or less, further preferably 1.4 or less.

[0053] The catalyst may also include a carrier for supporting the aforementioned elements. The carrier is not particularly limited, and examples thereof include silica, alumina, silica-alumina, magnesium oxide, titanium dioxide, and silicon carbide. Among these, when a carrier is used, silica is preferred to prevent the carrier itself from reacting. It should be noted that in the present invention, when a catalyst uses a carrier, the catalyst is also considered to include the carrier.

[0054] In the above formula (1), from the viewpoint of improving the selectivity of the target product, when a=12, the upper limit of g is preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less.

[0055] It should be noted that the composition of the catalyst is a value obtained by analyzing the components of the catalyst dissolved in aqueous ammonia using ICP emission spectroscopy. As an analytical instrument, for example, an ICP Optima 8300 (manufactured by Perkin Elmer) can be used. The analysis conditions are as follows: output power: 1300W, plasma gas flow rate: 10L / min, auxiliary gas flow rate: 0.2L / min, atomizer gas flow rate: 0.55L / min, detector: segmented array CCD. ICP emission spectroscopy is a method for measuring spectral lines emitted when atoms contained in a sample are excited when plasma energy is applied from the outside and when the excited atoms return to a lower energy level.

[0056] (Bismuth composition of catalyst surface relative to the entire catalyst)

[0057] In the catalyst of the present invention, when the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP emission spectroscopy is represented by A, and the ratio of the peak area of ​​bismuth atoms to the peak area of ​​molybdenum atoms measured by X-ray photoelectron spectroscopy is represented by B, B / A is 1.3 to 5. Here, A represents the ratio of the amount of bismuth atoms to the amount of molybdenum atoms in the entire catalyst, and B represents the ratio of the amount of bismuth atoms to the amount of molybdenum atoms on the catalyst surface. In other words, B / A represents the ratio of the amount of bismuth atoms present on the catalyst surface to the amount of bismuth atoms in the entire catalyst.

[0058] By satisfying the above-mentioned range with the B / A of catalyst, target product can be manufactured with high selectivity by raw material. The reason is not clear, but it is considered as follows. It is believed that bismuth plays the role of active site as reaction on the catalyst surface, and by making B / A be more than 1.3, that is, the amount of bismuth atoms present on the catalyst surface is sufficient, so that the selective oxidation reaction of target product is carried out, and the selectivity of target product improves. In addition, by making B / A be less than 5, that is, there is no excessive bismuth atoms on the catalyst surface, so as to suppress the stepwise reaction started by target product, and the selectivity of target product is suppressed to reduce.

[0059] Among the above, the lower limit of the B / A value is preferably 1.5 or more, more preferably 1.7 or more, and even more preferably 1.9 or more. The upper limit of the B / A value is preferably 4 or less, and more preferably 3 or less.

[0060] The lower limit of the value of A is preferably 0.02 or more, and more preferably 0.03 or more. The upper limit of the value of A is preferably 0.1 or less, and more preferably 0.09 or less.

[0061] The lower limit of the value of B is preferably 0.04 or more, more preferably 0.06 or more, and even more preferably 0.07 or more. The upper limit of the value of B is preferably 0.2 or less, more preferably 0.18 or less, and even more preferably 0.16 or less.

[0062] Methods for controlling the values ​​of A, B, and B / A include adjusting the type and amount of the molybdenum raw material, the type and amount of the bismuth raw material, the stirring time, the heating time, the heating temperature, etc., during the catalyst production process. Among these methods, the values ​​of A, B, and B / A can be controlled within desired ranges by stirring at a temperature 1 to 30°C lower than the boiling point of the solvent for 20 to 90 minutes in the later-described step (ii) and stirring at a temperature 2°C or higher than the boiling point of the solvent for 10 minutes to 10 hours in the step (iii).

[0063] It should be noted that in the present invention, the value of A is obtained by performing ICP emission spectrometry analysis of the catalyst as described above and calculating the ratio of the amount of bismuth atoms to the amount of molybdenum atoms. In addition, the value of B is obtained by performing X-ray photoelectron spectroscopy analysis of the catalyst and calculating the ratio of the peak area of ​​bismuth atoms to the peak area of ​​molybdenum atoms. As an analysis device, for example, Quantera II (manufactured by ULVAC-PHI) can be used. The analysis conditions are as follows: X-ray: HP mode-monochromatized Al ray source, output power: 300W, acquisition angle: 45°, and an X-ray beam diameter of 100μmφ is scanned linearly over a range of 1400μm. X-ray photoelectron spectroscopy is a method of determining the composition and chemical state of the elements constituting the sample surface by irradiating the sample surface with X-rays and measuring the kinetic energy of the photoelectrons released from the sample surface. Generally, information on the elements present in a few nm below the sample surface is obtained, so information on the composition and chemical state of the catalyst surface can be obtained.

[0064] (Density of catalyst)

[0065] The density of the catalyst is not particularly limited, but from the viewpoint of improving the durability of the catalyst, the lower limit is preferably 0.2 g / cm 3 More than 0.5 g / cm 3 More preferably, 1 g / cm 3 On the other hand, from the perspective of improving the selectivity of the target product, the upper limit is preferably 50 g / cm 3 Below, more preferably 30g / cm 3 Below, more preferably 20g / cm 3 the following.

[0066] [Method for producing catalyst]

[0067] Another embodiment of the present invention is a method for producing a catalyst containing at least molybdenum and bismuth, comprising the following steps (i) to (v). The B / A of the obtained catalyst is preferably 1.3 to 5.

[0068] (i) A step of mixing at least a molybdenum raw material and a bismuth raw material with a solvent to obtain a slurry (liquid A).

[0069] (ii) A step of stirring the liquid A at a temperature 1 to 30° C. lower than the boiling point of the solvent for 20 to 90 minutes to obtain a slurry (liquid B).

[0070] (iii) A step of stirring the liquid B at a temperature 2° C. or higher than the temperature in the step (ii) for 10 minutes to 10 hours to obtain a slurry (liquid C).

[0071] (iv) A step of drying the liquid C to obtain a dried product.

[0072] (v) A step of calcining the dried product to obtain a catalyst.

[0073] In addition, the method for producing the catalyst of the present invention may further include a molding step described later.

[0074] Hereinafter, each step will be described in detail.

[0075] (Process (i))

[0076] In step (i), at least a molybdenum raw material and a bismuth raw material are mixed with a solvent to obtain a slurry (liquid A). Liquid A is prepared by mixing the raw materials of molybdenum and bismuth with a solvent. In addition, the raw materials of each element contained in the above-mentioned formula (1) (hereinafter also referred to as catalyst raw materials) can be further mixed. The amount of the catalyst raw material used can be appropriately adjusted to the desired catalyst composition.

[0077] The catalyst raw material is not particularly limited, and nitrates, carbonates, bicarbonates, acetates, ammonium salts, sulfates, oxides, chlorides, hydroxides, halides, oxyacids, oxyacid salts, etc. of each element can be used alone or in combination of two or more.

[0078] Examples of molybdenum raw materials include ammonium paramolybdate, molybdenum trioxide, molybdic acid, and molybdenum chloride, with ammonium paramolybdate being preferred. Examples of bismuth raw materials include bismuth nitrate, bismuth oxide, and bismuth subcarbonate, with bismuth oxide being preferred. Examples of iron raw materials include ferric nitrate, ferric hydroxide, and ferric oxide, with ferric nitrate being preferred.

[0079] As a solvent, there is no particular limitation as long as it can dissolve or disperse the catalyst raw material. It is preferred that it contain at least water, more preferably 50% by mass or more of the entire solvent is water, and even more preferably 80% by mass or more of the entire solvent is water. Water alone may also be used. In addition, the solvent may include an organic solvent. As an organic solvent, there is no particular limitation, and examples thereof include ethanol, acetone, etc. The amount of solvent used is not particularly limited, but is preferably 30 to 400 parts by mass relative to a total of 100 parts by mass of the catalyst raw material.

[0080] The step (i) preferably includes the following steps (i-1) and (i-2).

[0081] (i-1) A step of preparing a solution or slurry (liquid A1) containing molybdenum, bismuth, and the elements X and Y in the above formula (1), and a solution or slurry (liquid A2) containing iron and the element M in the above formula (1).

[0082] (ii-2) A step of mixing the above-mentioned liquid A1 and the above-mentioned liquid A2 to prepare liquid A.

[0083] Hereinafter, each step will be described in detail.

[0084] <Process (i-1)>

[0085] In step (i-1), a solution or slurry (liquid A1) containing molybdenum, bismuth, and the elements X and Y in formula (1) above, and a solution or slurry (liquid A2) containing iron and the element M in formula (1) above are prepared. The order of preparing liquids A1 and A2 is not limited; liquids A1 and A2 may be prepared simultaneously.

[0086] The amount of each catalyst raw material used is preferably adjusted so that the resulting catalyst has the composition represented by the above formula (1).

[0087] The amount of solvent used is not particularly limited, but the amount of liquid A1 is preferably 70 to 400 parts by mass per 100 parts by mass of the total catalyst raw materials. The amount of liquid A2 is preferably 30 to 230 parts by mass per 100 parts by mass of the total catalyst raw materials.

[0088] <Process (i-2)>

[0089] In step (i-2), solution A is prepared by mixing solution A1 and solution A2 obtained in step (i-1).

[0090] (Step (ii))

[0091] In step (ii), the liquid A obtained in step (i) is stirred for 20 to 90 minutes at a temperature 1 to 30°C lower than the boiling point of the solvent to obtain a slurry (liquid B). For example, when water is used as the solvent in step (i), since the boiling point of water is 100°C, the liquid A is stirred at 70 to 99°C in step (ii). In addition, when multiple solvents with different boiling points are used in step (i), stirring is performed at a temperature 1 to 30°C lower than the boiling point of the solvent with the largest mass ratio.

[0092] In step (ii), when the catalyst raw material is dissolved in the solvent, the temperature and stirring time are set to the above conditions to adjust the solubility of the bismuth raw material to a certain level. It is believed that when the bismuth molybdate composite oxide layer is formed in the step (iii) described later, bismuth as an active site can be preferably precipitated on the surface, and a catalyst with a B / A of 1.5 to 5 can be obtained. When the temperature in step (ii) is lower than the specified value or the stirring time is shorter than the specified value, the solubility of the bismuth raw material becomes lower, and there is a tendency for the B / A of the obtained catalyst to become less than 1.5. On the other hand, when the temperature in step (ii) is higher than the specified value or the stirring time is longer than the specified value, the solubility of the molybdenum raw material and the bismuth raw material becomes higher, and there is a tendency for the B / A of the obtained catalyst to become greater than 5.

[0093] The upper limit of the temperature during stirring of Liquid A is preferably 3°C or more lower than the boiling point of the solvent, more preferably 5°C or more lower. The lower limit is preferably 25°C or less lower than the boiling point of the solvent, more preferably 20°C or less lower, and further preferably 10°C or less lower.

[0094] The lower limit of the stirring time in the above temperature range is preferably 30 minutes or more, more preferably 40 minutes or more, and the upper limit is preferably 80 minutes or less, more preferably 70 minutes or less.

[0095] (Process (iii))

[0096] In step (iii), the solution B obtained in step (ii) is stirred at a temperature 2° C. or higher than the temperature in step (ii) for 10 minutes to 10 hours to obtain a slurry (solution C).

[0097] In step (iii), a bismuth molybdate composite oxide layer is formed. At this time, it is believed that by stirring the B solution obtained by adjusting the solubility of bismuth in the above-mentioned step (ii) at the above-mentioned temperature for the above-mentioned time, bismuth as an active site can be preferably precipitated on the surface when the bismuth molybdate composite oxide layer is formed, and a catalyst with a B / A of 1.5 to 5 is obtained. When the temperature in step (iii) is lower than the specified value or the stirring time is shorter than the specified value, the precipitation of bismuth to the surface cannot be promoted, and there is a tendency for the B / A of the obtained catalyst to become less than 1.5. On the other hand, when the temperature in step (iii) is higher than the specified value or the stirring time is longer than the specified value, the precipitation of bismuth to the surface becomes excessive, and there is a tendency for the B / A of the obtained catalyst to become greater than 5.

[0098] The lower limit of the temperature during stirring of Solution B is preferably 3°C or higher than the temperature in step (ii), more preferably 5°C or higher, still more preferably 6°C or higher, and particularly preferably 8°C or higher. The upper limit is preferably 20°C or lower, more preferably 10°C or lower, higher than the temperature in step (ii).

[0099] The temperature during stirring of Solution B is preferably 1 to 20°C higher than the boiling point of the solvent. For example, when water is used as the solvent in step (i), since the boiling point of water is 100°C, Solution B is preferably stirred at 101 to 120°C in step (iii). The lower limit of the temperature during stirring of Solution B is more preferably 2°C or higher than the boiling point of the solvent, and more preferably 3°C or higher. The upper limit is more preferably 10°C or lower than the boiling point of the solvent, and more preferably 5°C or lower.

[0100] The lower limit of the time stirred in the above-mentioned temperature range is preferably more than 20 minutes, more preferably more than 30 minutes, further preferably more than 60 minutes, particularly preferably more than 90 minutes, and most preferably more than 2 hours. In addition, the upper limit is preferably below 9 hours, more preferably below 8 hours.

[0101] (Process (iv))

[0102] In step (iv), the liquid C obtained in step (iii) is dried to obtain a dried product.

[0103] Liquid C can be dried using known methods such as drum drying, airflow drying, evaporation to dryness, and spray drying. The drying temperature is preferably 120-500°C, with a more preferred lower limit of 140°C and an upper limit of 350°C. Drying is preferably performed so that the resulting dried product has a moisture content of 0.1-4.5% by mass. These conditions can be appropriately selected depending on the desired catalyst shape and size. Drying Liquid C can suppress adhesion of the dried product and improve yield.

[0104] (Process (v))

[0105] In step (v), the dried product obtained in step (iv) is calcined to obtain a catalyst. Calcination can be performed after the shaped product is obtained by the shaping step described below, but calcination is preferably performed before the shaping step from the perspective of catalyst strength. In the present invention, the shaped product, including these calcined and shaped products, is collectively referred to as a catalyst.

[0106] Calcination may be performed only once, or it may be performed in multiple steps along with the molding step described below. For example, calcination may be performed once, the resulting calcined product may be subjected to the molding step described below, and the resulting molded product may be calcined twice. Alternatively, calcination may be performed once and twice, and the resulting catalyst may be subjected to the molding step.

[0107] Calcination is preferably performed under the flow of an oxygen-containing gas such as air or an inert gas. "Inert gas" refers to a gas that does not reduce the activity of the catalyst, and examples thereof include nitrogen, carbon dioxide, helium, and argon.

[0108] The calcination temperature is preferably 200 to 700° C. The lower limit of the calcination temperature is more preferably 300° C. or higher, while the upper limit is more preferably 500° C. or lower, and further preferably 450° C. or lower.

[0109] The calcination time is preferably 0.5 to 40 hours, and the lower limit is more preferably 1 hour or longer.

[0110] Among the above, it is preferred that the dried product is calcined once and then molded, and the obtained molded product is calcined twice.

[0111] In this case, the calcination temperature of the primary calcination is preferably 200-600°C, more preferably with a lower limit of 250°C or higher and an upper limit of 450°C or lower. From the perspective of improving the selectivity of the target product, the calcination time of the primary calcination is preferably 0.5-5 hours. The type of calcination furnace and the method for calcining in the primary calcination are not particularly limited. For example, a box-type calcination furnace, a tunnel-type calcination furnace, etc. can be used to calcine the dried or shaped product in a fixed state. Alternatively, a rotary kiln or the like can be used to calcine the dried or shaped product while it is flowing.

[0112] The calcination temperature of the secondary calcination is preferably 300 to 700°C, more preferably with a lower limit of 400°C or higher and an upper limit of 600°C or lower. From the perspective of improving the selectivity of the target product, the calcination time of the secondary calcination is preferably 10 minutes to 10 hours, with a lower limit of 1 hour or more. The type of calcination apparatus and the method for the secondary calcination are not particularly limited. For example, a box-type calcination furnace, a tunnel-type calcination furnace, etc. can be used to calcine the molded product or the primary calcined product in a fixed state. Alternatively, a rotary kiln or the like can be used to calcine the molded product or the primary calcined product while it is flowing.

[0113] (Molding process)

[0114] In the molding step, the dried product obtained in step (iv) or the calcined product obtained in step (v) is molded to obtain a molded product. The molding method is not particularly limited, and known dry or wet molding methods can be used. Examples include tablet molding, extrusion molding, press molding, and tumbling granulation.

[0115] During molding, conventionally known additives such as organic compounds such as polyvinyl alcohol and carboxymethyl cellulose may be added. Inorganic compounds such as graphite and diatomaceous earth, and inorganic fibers such as glass fibers, ceramic fibers, and carbon fibers may also be added.

[0116] The shape of the molded article is not particularly limited, and any shape such as spherical, cylindrical, annular, star-shaped, and granular shapes that are crushed and classified after molding can be mentioned. Among these, spherical, cylindrical, and annular shapes are preferred from the perspective of mechanical strength. The size of the molded article is not particularly limited. For example, in the case of a spherical shape, the diameter of the sphere is preferably 0.1 to 10 mm. The lower limit of the diameter of the sphere is more preferably 0.5 mm or more, more preferably 1 mm or more, and particularly preferably 3 mm or more. In addition, the upper limit of the diameter of the sphere is more preferably 8 mm or less, and further preferably 6 mm or less. In the case of an annular or cylindrical shape, the diameter and height of the circle of the bottom surface of the ring or cylinder are both preferably 0.1 to 10 mm. The lower limits of the diameter and height are more preferably 0.5 mm or more, more preferably 1 mm or more, and particularly preferably 3 mm or more. In addition, the upper limits of the diameter and height are more preferably 8 mm or less, and further preferably 6 mm or less. In the case of other shapes, the length between the two farthest points in the catalyst is preferably 0.1 to 10 mm. The lower limit of the length between the two points is more preferably 0.5 mm or more, further preferably 1 mm or more, and particularly preferably 3 mm or more. In addition, the upper limit of the length between the two points is more preferably 8 mm or less, further preferably 6 mm or less. Thus, the selectivity of the target product and the catalyst life are improved.

[0117] The outer surface area of ​​the molded product is not particularly limited, but from the perspective of long-term stable production of the target product, the lower limit is preferably 0.01 cm2 More than 0.05 cm 2 More than 0.1 cm 2 On the other hand, from the perspective of improving the selectivity of the target product, the upper limit is preferably 4 cm 2 Below, more preferably 3cm 2 Below, more preferably 2cm 2 the following.

[0118] The volume of the molded product is not particularly limited, but from the perspective of long-term stable production of the target product, the lower limit is preferably 0.0002 cm 3 More than 0.002 cm 3 More preferably, 0.02 cm 3 On the other hand, from the perspective of improving the selectivity of the target product, the upper limit is preferably 5 cm 3 Less than 1 cm, more preferably 1 cm 3 Below, more preferably 0.5cm 3 the following.

[0119] The mass of the molded article is not particularly limited. However, from the perspective of long-term stable production of the target product, the lower limit is preferably 0.002 g / article or greater, more preferably 0.01 g / article or greater, and even more preferably 0.05 g / article or greater. On the other hand, from the perspective of increasing the selectivity of the target product, the upper limit is preferably 0.5 g / article or less, more preferably 0.3 g / article or less, and even more preferably 0.2 g / article or less.

[0120] The packing density of the molded product is not particularly limited, but the lower limit is preferably 0.2 g / cm 3 More than 0.3 g / cm 3 More preferably, 0.4 g / cm 3 On the other hand, from the perspective of improving the selectivity of the target product, the upper limit is preferably 1 g / cm 3 Below, more preferably 0.9g / cm 3 Below, more preferably 0.8 g / cm 3 The packing bulk density of a molded product is 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 in accordance with JIS-K7365.

[0121] The resulting molded product can be supported on a carrier. Examples of carriers used for this purpose include silica, alumina, silica-alumina, magnesia, titania, and silicon carbide. Furthermore, the molded product can be diluted with an inactive substance such as silica, alumina, silica-alumina, magnesia, titania, and silicon carbide before use.

[0122] The catalyst can be produced as described above.

[0123] [Method for producing α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid]

[0124] In the method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid of the present invention, the corresponding α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid is produced from an olefin, an alcohol, or an ether using the catalyst of the present invention or the catalyst produced by the production method of the present invention.

[0125] Examples of the above-mentioned olefins include propylene and isobutylene. Examples of the above-mentioned alcohols include tert-butyl alcohol and isobutyl alcohol. Examples of the above-mentioned ethers include methyl tert-butyl ether. The corresponding α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids can be produced by oxidizing these raw organic compounds. For example, when the raw organic compound is propylene, the corresponding α,β-unsaturated aldehyde is acrolein, and the corresponding α,β-unsaturated carboxylic acid is acrylic acid. Furthermore, when the raw organic compound is isobutylene, tert-butyl alcohol, isobutyl alcohol, or methyl tert-butyl ether, the corresponding α,β-unsaturated aldehyde is methacrolein, and the corresponding α,β-unsaturated carboxylic acid is methacrylic acid. From the perspective of selectivity for the target product, the α,β-unsaturated aldehyde and the α,β-unsaturated carboxylic acid are preferably methacrolein and methacrylic acid, respectively.

[0126] The method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid of the present invention can be carried out by contacting the catalyst of the present invention or the catalyst produced by the production method of the present invention with the raw material organic compound and the oxygen-containing raw material gas in a reactor.

[0127] The reactor is not particularly limited, but a tubular reactor equipped with a reaction tube filled with catalyst is preferably used. Industrially, a multitubular reactor equipped with multiple reaction tubes is more preferably used. The catalyst layer within the reactor may be a single layer, or multiple catalysts with different activities may be packed separately into multiple layers. Furthermore, the catalyst may be diluted with an inactive carrier before packing to control activity.

[0128] The concentration of the raw material organic compound in the raw material gas is preferably 1 to 20% by volume, more preferably with a lower limit of 3% by volume or greater and an upper limit of 10% by volume or less. It should be noted that the raw material organic compound may contain a small amount of impurities such as lower saturated alkanes that do not substantially affect the reaction.

[0129] The concentration of oxygen in the raw material gas is preferably 0.1 to 5 moles per mole of the raw material organic compound, with a more preferred lower limit being 0.5 moles or more and an upper limit being 3 moles or less. From an economical perspective, air is preferably used as the oxygen source for the raw material gas. Alternatively, a gas enriched in oxygen by mixing pure oxygen with air or the like may be used as needed.

[0130] From an economical perspective, the raw material gas may be diluted with an inert gas such as nitrogen or carbon dioxide. Water vapor may also be added to the raw material gas. By conducting the reaction in the presence of water vapor, α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids can be obtained with higher selectivity. The water vapor concentration in the raw material gas is preferably 0.1 to 50% by volume, with a more preferred lower limit of 1% by volume and an upper limit of 40% by volume.

[0131] The reaction pressure is preferably 0 to 1 MPa(G). Here, "(G)" represents a gauge pressure, and 0 MPa(G) indicates that the reaction pressure is atmospheric pressure. Furthermore, the reaction temperature is preferably 200 to 450°C, with a more preferred lower limit being 250°C or higher and an upper limit being 400°C or lower.

[0132] The contact time between the raw material gas and the catalyst is preferably 0.5 to 15 seconds. The lower limit of the contact time is more preferably 1 second or longer, while the upper limit is more preferably 10 seconds or shorter, and even more preferably 5 seconds or shorter.

[0133] By producing as described above, it is possible to obtain an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid corresponding to the raw material organic compound used with high selectivity.

[0134] [Method for producing α,β-unsaturated carboxylic acid]

[0135] In the method for producing an α,β-unsaturated carboxylic acid of the present invention, the corresponding α,β-unsaturated carboxylic acid or the like is produced from the α,β-unsaturated aldehyde produced by the production method of the present invention.

[0136] Examples of the above-mentioned α,β-unsaturated aldehydes include (meth)acrolein, crotonaldehyde (β-methacrolein), and cinnamaldehyde (β-phenylacrolein). The α,β-unsaturated carboxylic acid produced is an α,β-unsaturated carboxylic acid obtained by converting the aldehyde group of the above-mentioned α,β-unsaturated aldehyde into a carboxyl group. Specifically, when the α,β-unsaturated aldehyde is (meth)acrolein, (meth)acrylic acid is obtained. From the viewpoint of the selectivity of the target product, the α,β-unsaturated aldehyde and the α,β-unsaturated carboxylic acid are preferably (meth)acrolein and (meth)acrylic acid, respectively, and more preferably methacrolein and methacrylic acid. It should be noted that "(meth)acrolein" means acrolein and methacrolein, and "(meth)acrylic acid" means acrylic acid and methacrylic acid.

[0137] The method for producing an α,β-unsaturated carboxylic acid of the present invention can be carried out by contacting the catalyst of the present invention or the catalyst produced by the method of the present invention with an α,β-unsaturated aldehyde and a raw material gas containing oxygen within a reactor. A heteropolyacid catalyst or the like is preferably used as the catalyst. The reactor can be the same as that used in the above-mentioned method for producing an α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid. The catalyst layer within the reactor may be a single layer, or multiple layers of catalysts having different activities may be packed separately. Furthermore, the catalyst may be diluted with an inactive carrier before packing to control activity.

[0138] The concentration of the α,β-unsaturated aldehyde in the raw material gas is preferably 1 to 20% by volume, with a more preferred lower limit being 3% by volume or higher and an upper limit being 10% by volume or lower. The α,β-unsaturated aldehyde may contain a small amount of impurities such as lower saturated aldehydes that do not substantially affect the reaction.

[0139] The oxygen concentration in the raw material gas is preferably 0.4 to 4 mol per mol of the α,β-unsaturated aldehyde, with a more preferred lower limit of 0.5 mol or higher and an upper limit of 3 mol or lower. From an economical perspective, air is preferably used as the oxygen source for the raw material gas. Alternatively, a gas enriched in oxygen, such as air, may be used as needed, by mixing pure oxygen with air.

[0140] From an economical perspective, the raw material gas can be diluted with an inert gas such as nitrogen or carbon dioxide. Water vapor can also be added to the raw material gas. By conducting the reaction in the presence of water vapor, the α,β-unsaturated carboxylic acid can be obtained with higher selectivity. The water vapor concentration in the raw material gas is preferably 0.1 to 50% by volume, with a more preferred lower limit of 1% by volume and an upper limit of 40% by volume.

[0141] The reaction pressure is preferably 0 to 1 MPa(G). The reaction temperature is preferably 200 to 450°C, and more preferably the lower limit is 250°C or higher and the upper limit is 400°C or lower.

[0142] The contact time between the raw material gas and the catalyst is preferably 0.5 to 15 seconds. The lower limit of the contact time is more preferably 1 second or longer, while the upper limit is more preferably 10 seconds or shorter, and even more preferably 5 seconds or shorter.

[0143] [Method for producing α,β-unsaturated carboxylic acid ester]

[0144] In the method for producing an α,β-unsaturated carboxylic acid ester of the present invention, the α,β-unsaturated carboxylic acid produced by the production method of the present invention is esterified. The alcohol reacting with the α,β-unsaturated carboxylic acid is not particularly limited, and examples thereof include methanol, ethanol, propanol, isopropanol, butanol, and isobutanol. Examples of the resulting α,β-unsaturated carboxylic acid ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, and isobutyl (meth)acrylate. The reaction can be carried out in the presence of an acidic catalyst such as a sulfonic acid-type cation exchange resin. The reaction temperature is preferably 50 to 200°C.

[0145] Example

[0146] Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In addition, "parts" in Examples and Comparative Examples represent parts by mass.

[0147] (Composition of Catalyst)

[0148] The overall composition of the catalyst was determined by analyzing the components of the catalyst dissolved in aqueous ammonia using ICP emission spectroscopy. The analyzer used was an ICP Optima 8300 (Perkin Elmer) with an output of 1300 W, a plasma gas flow rate of 10 L / min, an assist gas flow rate of 0.2 L / min, a nebulizer gas flow rate of 0.55 L / min, and a segmented array CCD detector.

[0149] In addition, the value of A was calculated from the ratio of the amount of bismuth atoms to the amount of molybdenum atoms in the composition of the entire catalyst obtained.

[0150] (X-ray Photoelectron Spectroscopy Analysis of Catalysts)

[0151] The B value was determined by X-ray photoelectron spectroscopy of the catalyst and calculating the ratio of the peak area of ​​bismuth atoms to the peak area of ​​molybdenum atoms. The analyzer used was a Quantera II (manufactured by ULVAC-PHI), with an X-ray beam in HP mode and a monochromatized Al source, an output of 300 W, and a 45° acquisition angle. The X-ray beam was scanned linearly over a range of 1400 μm with a diameter of 100 μm.

[0152] (Reaction Evaluation)

[0153] The reaction evaluation of the catalysts in the Examples and Comparative Examples was performed using the production of methacrolein and methacrylic acid by oxidation of isobutylene as an example. The raw material gas and product analysis in the reaction evaluation were performed using the following gas chromatography method.

[0154] Methacrolein analysis: Shimadzu GC-2014, column: QUADREX 007-CW 20m×0.32mm, film thickness: 3μm

[0155] Analysis of methacrylic acid: GC-2014 manufactured by Shimadzu Corporation, column: DB-FFAP manufactured by J&W, 30 m × 0.32 mm, film thickness 1.00 μm

[0156] From the results of gas chromatography, the total selectivity of generated methacrolein and methacrylic acid was determined by the following formula.

[0157] Total selectivity of methacrolein and methacrylic acid (%) = (P1 + P2) / M1 × 100

[0158] In the above formula, M1 is the number of moles of isobutylene reacted per unit time, P1 is the number of moles of methacrolein produced per unit time, and P2 is the number of moles of methacrylic acid produced per unit time.

[0159] <Example 1>

[0160] Liquid A1 was prepared by mixing 500 parts by mass of ammonium paramolybdate tetrahydrate, 12.3 parts by mass of ammonium paratungstate, 27.6 parts by mass of cesium nitrate, 38.5 parts by mass of bismuth (III) oxide, and 20.6 parts by mass of antimony trioxide in 2000 parts by mass of pure water at 60°C. Separately, in addition to Liquid A1, 200.2 parts by mass of iron (III) nitrate nonahydrate and 515.1 parts by mass of cobalt (II) nitrate hexahydrate were mixed in 1000 parts by mass of pure water to prepare Liquid A2. Subsequently, Liquids A1 and A2 were mixed to prepare Liquid A.

[0161] The obtained solution A was heated to 95° C. and stirred for 1 hour while maintaining the solution temperature at 95° C. to obtain solution B.

[0162] The obtained solution B was heated to 103° C. and stirred for 3 hours while maintaining the solution temperature at 103° C. to obtain solution C.

[0163] The obtained liquid C was dried using a spray dryer to obtain a dried product. The dried product was not adhered to the inner wall surface of the spray dryer and was in a well-dried state.

[0164] The resulting dried product was calcined once at 300°C for one hour in an air atmosphere and then pulverized. The calcined dried product was then press-molded and pulverized to produce pulverized particles. The pulverized particles were then classified and passed through a 2.36 mm sieve, while those that did not pass through a 0.71 mm sieve were recovered. The recovered pulverized particles were then calcined twice at 500°C for three hours in an air atmosphere to produce a catalyst.

[0165] The oxygen-removing composition of the obtained catalyst is Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 Sb 0.6 Cs 0.6 In addition, the catalyst was subjected to ICP emission spectrometry and X-ray photoelectron spectroscopy. The calculated values ​​of A, B, and B / A are shown in Table 1.

[0166] Next, the obtained catalyst was filled into a stainless steel reaction tube to form a catalyst layer, and an oxidation reaction of isobutylene was carried out under the following conditions. The results are shown in Table 1.

[0167] Raw gas composition: isobutylene 5% by volume, oxygen 12% by volume, water vapor 10% by volume, and nitrogen 73% by volume

[0168] Reaction temperature: 340℃

[0169] Contact time between raw gas and catalyst: 2.7 seconds

[0170] <Example 2>

[0171] Liquid A1 was prepared in the same manner as in Example 1 except that the amount of antimony trioxide was changed to 24.8 parts by mass. Liquid A2 was prepared separately from Liquid A1 in the same manner as in Example 1. Liquid A1 and Liquid A2 were then mixed to obtain Liquid A.

[0172] The obtained solution A was heated to 95° C. and stirred for 1 hour while maintaining the solution temperature at 95° C. to obtain solution B.

[0173] The obtained solution B was heated to 103° C. and stirred for 5 hours while maintaining the solution temperature at 103° C. to obtain solution C.

[0174] The obtained liquid C was dried using a spray dryer to obtain a dried product. The dried product was not adhered to the inner wall surface of the spray dryer and was in a well-dried state.

[0175] The obtained dried product was calcined once, molded, and calcined twice in the same manner as in Example 1 to obtain a catalyst.

[0176] The oxygen-removing composition of the obtained catalyst is Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 Sb 0.72 Cs 0.6In addition, the catalyst was subjected to ICP emission spectrometry and X-ray photoelectron spectroscopy. The calculated values ​​of A, B, and B / A are shown in Table 1.

[0177] Next, reaction evaluation was performed using the obtained catalyst in the same manner as in Example 1. The results are shown in Table 1.

[0178] <Example 3>

[0179] Liquid A1 was prepared in the same manner as in Example 1 except that the amount of antimony trioxide was 15.5 parts by mass. Liquid A2 was prepared separately from Liquid A1 in the same manner as in Example 1. Liquid A2 was then mixed with Liquid A1 to obtain Liquid A.

[0180] The obtained liquid was heated to 95° C., and the liquid temperature was maintained at 95° C. with stirring for 1 hour to obtain Liquid B.

[0181] The obtained solution B was heated to 103° C. and stirred for 7 hours while maintaining the solution temperature at 103° C. to obtain solution C.

[0182] The obtained liquid C was dried using a spray dryer to obtain a dried product. The dried product was not adhered to the inner wall surface of the spray dryer and was in a well-dried state.

[0183] The obtained dried product was calcined once, molded, and calcined twice in the same manner as in Example 1 to obtain a catalyst.

[0184] The oxygen-removing composition of the obtained catalyst is Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 Sb 0.45 Cs 0.6 In addition, the catalyst was subjected to ICP emission spectrometry and X-ray photoelectron spectroscopy. The calculated values ​​of A, B, and B / A are shown in Table 1.

[0185] Next, reaction evaluation was performed using the obtained catalyst in the same manner as in Example 1. The results are shown in Table 1.

[0186] Comparative Example 1

[0187] Solution B was obtained by the same method as in Example 1.

[0188] The obtained solution B was dried using a spray dryer to obtain a dried product. That is, the dried product was obtained by drying the solution B without performing step (iii). The dried product did not adhere to the inner wall surface of the spray dryer and was in a well-dried state.

[0189] The obtained dried product was calcined once, molded, and calcined twice in the same manner as in Example 1 to obtain a catalyst.

[0190] The oxygen-removing composition of the obtained catalyst is Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 Sb 0.6 Cs 0.6 In addition, the catalyst was subjected to ICP emission spectrometry and X-ray photoelectron spectroscopy. The calculated values ​​of A, B, and B / A are shown in Table 1.

[0191] Next, reaction evaluation was performed using the obtained catalyst in the same manner as in Example 1. The results are shown in Table 1.

[0192] Comparative Example 2

[0193] Liquid A was obtained by the same method as in Example 1.

[0194] The obtained solution A was heated to 95° C. and stirred for 2 hours while maintaining the solution temperature at 95° C. That is, the solution B′ was obtained by stirring for longer than 90 minutes in step (ii).

[0195] The obtained solution B' was heated to 100°C and stirred for 1 hour while maintaining the solution temperature at 100°C to obtain solution C.

[0196] The obtained liquid C was dried using a spray dryer to obtain a dried product. The dried product was not adhered to the inner wall surface of the spray dryer and was in a well-dried state.

[0197] The obtained dried product was calcined once, molded, and calcined twice in the same manner as in Example 1 to obtain a catalyst.

[0198] The oxygen-removing composition of the obtained catalyst is Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 Sb 0.6 Cs 0.6 In addition, the catalyst was subjected to ICP emission spectrometry and X-ray photoelectron spectroscopy. The calculated values ​​of A, B, and B / A are shown in Table 1.

[0199] Next, reaction evaluation was performed using the obtained catalyst in the same manner as in Example 1. The results are shown in Table 1.

[0200] Table 1

[0201]

[0202] As can be seen from Table 1, Examples 1 to 3 using catalysts having a B / A ratio within a predetermined range have a good total selectivity for methacrolein and methacrylic acid.

[0203] It should be noted that methacrylic acid can be obtained by oxidizing the methacrolein obtained in this example, and methacrylic acid can be obtained by esterifying the methacrylic acid.

[0204] Industrial applicability

[0205] According to the present invention, a catalyst for producing a target product such as an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid with high selectivity can be provided, which is industrially useful.

Claims

1. A catalyst comprising at least molybdenum and bismuth, used in the production of α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids from olefins, alcohols or ethers. When the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP (inductively coupled plasma emission spectrometry) is defined as A and the ratio of the peak area of ​​bismuth atoms to the peak area of ​​molybdenum atoms measured by X-ray photoelectron spectroscopy is defined as B, B / A is 1.5 to 4, The value of A is 0.02 to 0.1, The value of B is 0.04 to 0.2, The catalyst composition is represented by the following formula (1): Know a Like b Want c M d X e Yes f To g SHE h (1) In the formula (1), Mo, Bi, Fe, Si and O represent molybdenum, bismuth, iron, silicon and oxygen, respectively; M represents at least one element selected from cobalt and nickel; X represents at least one element selected from zinc, chromium, lead, manganese, calcium, magnesium, niobium, silver, barium, tin, tantalum, tungsten, antimony, phosphorus, boron, sulfur, selenium, tellurium, cerium and titanium; Y represents at least one element selected from cesium, lithium, sodium, potassium, rubidium and thallium; a, b, c, d, e, f, g and h represent the atomic ratio of each element; when a=12, b=0.01-3, c=0-8, d=0-12, e=0-8, f=0.001-2, g=0-20, and h is the oxygen atomic ratio required to satisfy the atomic valence of each component.

2. The catalyst according to claim 1, wherein The value of B / A is 1.7-3.

3. The catalyst according to claim 1, wherein The value of B is 0.07 to 0.

16.

4. A method for producing a catalyst comprising at least molybdenum and bismuth and used in the production of an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid from an olefin, an alcohol, or an ether, the method comprising the following steps (i) to (v): (i) a step of mixing at least a molybdenum raw material and a bismuth raw material with a solvent to obtain a slurry, i.e., a liquid A; (ii) stirring the liquid A at a temperature 1 to 30° C. lower than the boiling point of the solvent for 20 to 90 minutes to obtain a slurry, namely, liquid B; (iii) stirring the liquid B at a temperature 2°C higher than the temperature in step (ii) for 10 minutes to 10 hours to obtain a slurry, namely, liquid C; (iv) drying the liquid C to obtain a dried product, and (v) a step of calcining the dried product to obtain a catalyst; In the catalyst, when the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP (inductively coupled plasma emission spectrometry) is defined as A and the ratio of the peak area of ​​bismuth atoms to the peak area of ​​molybdenum atoms measured by X-ray photoelectron spectroscopy is defined as B, B / A is 1.5 to 4, The value of A is 0.02 to 0.1, The value of B is 0.04 to 0.2, The catalyst has a composition represented by the following formula (1), Know a Like b Want c M d X e Yes f To g SHE h (1) In the formula (1), Mo, Bi, Fe, Si and O represent molybdenum, bismuth, iron, silicon and oxygen, respectively; M represents at least one element selected from cobalt and nickel; X represents at least one element selected from zinc, chromium, lead, manganese, calcium, magnesium, niobium, silver, barium, tin, tantalum, tungsten, antimony, phosphorus, boron, sulfur, selenium, tellurium, cerium and titanium; Y represents at least one element selected from cesium, lithium, sodium, potassium, rubidium and thallium; a, b, c, d, e, f, g and h represent the atomic ratio of each element; when a=12, b=0.01-3, c=0-8, d=0-12, e=0-8, f=0.001-2, g=0-20, and h is the oxygen atomic ratio required to satisfy the atomic valence of each component.

5. The method for producing a catalyst according to claim 4, wherein In the step (i), 50% by mass or more of the entire solvent is water.

6. The method for producing a catalyst according to claim 4, wherein The temperature in the step (iii) is 1 to 20° C. higher than the boiling point of the solvent.

7. The method for producing a catalyst according to claim 4, wherein: In the step (iii), the solution B is stirred for 90 minutes to 10 hours to obtain the solution C. A method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid, comprising producing the α,β-unsaturated aldehyde and / or the α,β-unsaturated carboxylic acid from an olefin, an alcohol or an ether using the catalyst according to any one of claims 1 to 3. A method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid, comprising producing the α,β-unsaturated aldehyde and / or the α,β-unsaturated carboxylic acid from an olefin, an alcohol or an ether using the 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 producing an α,β-unsaturated carboxylic acid from an α,β-unsaturated aldehyde produced by the method according to claim 8 . A method for producing an α,β-unsaturated carboxylic acid, comprising producing an α,β-unsaturated carboxylic acid from an 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 producing the α,β-unsaturated carboxylic acid ester from the α,β-unsaturated carboxylic acid produced by the method according to claim 8 . 13 . A method for producing an α,β-unsaturated carboxylic acid ester, comprising producing the α,β-unsaturated carboxylic acid ester from the α,β-unsaturated carboxylic acid produced by the method according to claim 9 .

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