Catalyst, method for producing the catalyst, and method for producing α,β-unsaturated aldehydes, α,β-unsaturated carboxylic acids, and α,β-unsaturated carboxylic acid esters.

Abstract

To provide a catalyst having a high selectivity of an α,β-unsaturated aldehyde, an α,β-unsaturated carboxylic acid, and the like.SOLUTION: A catalyst contains at least molybdenum and bismuth, and has a B / A of 1.3 to 5 where A is a ratio of an amount of a bismuth atom to an amount of a molybdenum atom calculated from an ICP (inductive coupling high-frequency plasma) emission spectrography, and B is a ratio of a peak area of a bismuth atom to a peak area of a molybdenum atom measured by an X-ray photoelectron spectrographic analysis.SELECTED DRAWING: None

Description

Technical Field

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

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

[0003] For example, Patent Document 1 describes, as a method for producing a catalyst used when producing a corresponding unsaturated aldehyde and unsaturated carboxylic acid from an olefin, a method for producing a composite oxide catalyst containing at least molybdenum, bismuth, cobalt and / or nickel, and iron. Patent Document 2 also describes an example in which a catalyst for synthesizing unsaturated aldehydes and unsaturated carboxylic acids excellent in catalytic activity and selectivity can be provided, wherein the catalyst is composed of composite oxide particles containing at least molybdenum, iron and cobalt, and the atomic ratio of the bulk composition and the surface composition of the particles satisfies specific conditions. Prior Art Documents Patent Documents

[0004] Patent Document 1 Japanese Unexamined Patent Publication No. 2005-169311 Patent Document 2 Japanese Unexamined Patent Publication No. 2011-115681 Summary of the Invention Problems to be Solved by the Invention

[0005] However, our research has revealed that the catalysts described in Patent Documents 1 and 2 do not always perform sufficiently and can produce many by-products. Since these problems affect the selectivity of α,β-unsaturated aldehydes and α,β-unsaturated carboxylic acids, further improvement in catalyst performance is desired. Therefore, from the viewpoint of further improving catalyst performance, controlling the catalytic properties is required. The present invention has been made in view of the above circumstances, and aims to provide a catalyst that has a high selectivity for target products such as α,β-unsaturated aldehydes and α,β-unsaturated carboxylic acids. [Means for solving the problem]

[0006] The inventors diligently conducted research to achieve the above objective. As a result, they 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. In other words, the present invention includes the following:

[0007] [1]: A catalyst containing at least molybdenum and bismuth, Let A be the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP (Inductively Coupled Radio Frequency Plasma) emission spectroscopy, and let B be the ratio of the peak area of ​​bismuth atoms to the peak area of ​​molybdenum atoms measured by X-ray photoelectron spectroscopy. Then, if B / A is 1 A catalyst with a value of 0.3 to 0.5. [2]: The catalyst according to [1], wherein the B / A value is 1.5 to 4. [3]: The catalyst according to [1] or [2], wherein the B / A value is 1.7 to 3. [4]: The catalyst according to any of [1] to [3], wherein the value of A is 0.02 to 0.1. [5]: The catalyst according to any of [1] to [4], wherein the value of B is 0.04 to 0.2. [6]: The catalyst according to any of [1] to [5], wherein the value of B is 0.07 to 0.16. [7]: A catalyst according to any one of [1] to [6] used in producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids from alkenes, alcohols, or ethers. [8]: A catalyst whose catalyst composition is represented by the following formula (1), as described in any of [1] to [7]. Mo a Bi b Fe c M d X e Y f Si g O h (1) (In formula (1) above, Mo, Bi, Fe, Si, and O represent molybdenum, bismuth, iron, silicon, and oxygen, respectively. M represents at least one element selected from the group consisting of cobalt and nickel. X represents at least one element selected from the group consisting of 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 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, c=0~8, d=0~12, e=0~8, f=0.001~2, g=0~20, and h is the valence of each component.) This is the oxygen atom ratio required to satisfy the condition. [9] A method for producing a catalyst containing at least molybdenum and bismuth, comprising the following steps (i) to (v). (i) A step of mixing at least molybdenum raw material and bismuth raw material with a solvent to obtain a slurry (liquid A), (ii) A step of stirring the above 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), (iii) A step of stirring liquid B at a temperature 2°C or more higher than the temperature in step (ii) for 10 minutes to 10 hours to obtain a slurry (liquid C), (iv) A step of drying the C solution to obtain a dried product, (v) a step of calcining the dried product to obtain a catalyst.

[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.

[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.

[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.

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

[12] , which produces a catalyst used for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid from an alkene, an alcohol or an ether.

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

[13] , which produces a catalyst having a composition represented by the following formula (1). Mo a Bi b Fe c M d X e Y f Si g O h (1) (In the formula (1), Mo, Bi, Fe, Si and O each represent molybdenum, bismuth, iron, silicon and oxygen, M represents at least one element selected from the group consisting of cobalt and nickel, X represents at least one element selected from the group consisting of zinc, chromium, lead, manganese, calcium, magnesium, niobium, silver, barium, tin, tantalum, tungsten, antimony, phosphorus, boron, sulfur, selenium, tellurium, cerium and titanium, Y is selected from the group consisting of cesium, lithium, sodium, potassium, rubidium and thallium represents at least one element selected from the group. a, b, c, d, e, f, g and h each represent an atomic ratio of the corresponding element, when a=12, b=0.01 to 3, c=0 to 8, d=0 to 12, e=0 to 8, f=0.001 to 2, g=0 to 20, and h is the valence of each of the aforementioned components is the oxygen atomic ratio required to satisfy the condition.)

[15] : A method for producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids from an alkene, an alcohol, or an ether using a catalyst described in any of [1] to [8].

[16] : A method for producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids from alkenes, alcohols, or ethers using a catalyst produced by a catalyst production method described in any of [9] to

[14] .

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

[15] or

[16] . A method for producing an α,β-unsaturated carboxylic acid ester from an α,β-unsaturated carboxylic acid produced by any of the manufacturing methods described in

[15] to

[17] . [Effects of the Invention]

[0008] According to the present invention, a catalyst with high selectivity for the target product can be provided. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will be described below, but the present invention is not limited to the above. Furthermore, unless otherwise specified, the notation "XX or more and YY or less" or "XX~YY" that represents a numerical range means a numerical range that includes the lower and upper limits which are the endpoints. When a numerical range is described in steps, the upper and lower limits of each numerical range can be combined arbitrarily.

[0010] [catalyst] The catalyst according to the present invention is a catalyst containing at least molybdenum and bismuth, wherein when A is the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP (inductively coupled radio frequency 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 raw materials with high selectivity. The catalyst according to the present invention is preferably an oxidation catalyst from the viewpoint of selectivity of the target product, and more preferably a catalyst used in producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids. Specifically, it is preferably a catalyst for producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids from alkenes, alcohols, or ethers. Note that "producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids" means that either one of α,β-unsaturated aldehydes and α,β-unsaturated carboxylic acids may be produced, or both may be produced.

[0011] (Composition of the catalyst) The catalyst according to the present invention preferably contains at least molybdenum and bismuth and has a composition represented by the following formula (1). The catalyst components may also contain small amounts of elements not listed in formula (1). Mo a Bi b Fe c M d X e Y f Si g O h (1) 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 the group consisting of cobalt and nickel. X represents zinc, chromium, lead, manganese, calcium, magnesium, and niosyl alcohol. Y represents at least one element selected from the group consisting of blue, silver, barium, tin, tantalum, tungsten, antimony, phosphorus, boron, sulfur, selenium, tellurium, cerium, 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, c=0~8, d=0~12, e=0~8, f=0.001~2, g=0~20, and h satisfies the valence of each component. This is the ratio of oxygen atoms needed to add them together.

[0012] In formula (1) above, from the viewpoint of improving the selectivity of the target product, when a = 12, the lower limit of b is preferably 0.03 or higher, and more preferably 0.05 or higher. The upper limit of b is preferably 2 or lower, and more preferably 1 or lower. The lower limit of c is preferably 0.01 or higher, more preferably 0.1 or higher, even more preferably 1 or higher, and particularly preferably 3 or higher. The upper limit of c is preferably 6 or lower, and more preferably 4 or lower.

[0013] The catalyst contains molybdenum, bismuth, and iron if necessary, but may also contain other elements besides these, such as elements M, X, and Y in formula (1). Among the other elements, it is preferable to contain element M, and it is even more preferable to contain element Y.

[0014] In formula (1) above, from the viewpoint of improving the selectivity of the target product, when a = 12, the lower limit of d is preferably 0.01 or higher, more preferably 0.1 or higher, even more preferably 1 or higher, and particularly preferably 3 or higher. The upper limit of d is preferably 10 or lower, more preferably 9 or lower. The lower limit of e is preferably 0.1 or higher, more preferably 0.2 or higher, and even more preferably 0.5 or higher. The upper limit of e is preferably 6 or lower, more preferably 4 or lower. The lower limit of f is preferably 0.05 or higher, more preferably 0.1 or higher, and even more preferably 0.2 or higher. The upper limit of f is preferably 1.8 or lower, more preferably 1.6 or lower, and even more preferably 1.4 or lower.

[0015] The catalyst may also have a support for bearing the above elements. The support is not particularly limited and includes silica, alumina, silica-alumina, magnesia, titania, silicon carbide, etc. Among these, when a support is used, silica is preferred as the support to prevent the support itself from reacting. In this invention, when a support is used in the catalyst, the support is also considered as part of the catalyst.

[0016] In formula (1) above, 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.

[0017] The catalyst composition is determined by analyzing the components of the catalyst dissolved in ammonia water using ICP emission spectrometry. For example, an ICP Optima 8300 (manufactured by Perkin Elmer) can be used as the analytical instrument. The analytical conditions are: power output: 1300W, plasma gas flow rate: 10L / min, auxiliary gas flow rate: 0.2L / min, nebulizer gas flow rate: 0.55L / min, and detector: segmented array type CCD. ICP emission spectrometry is a method in which plasma energy is applied to a sample from an external source, exciting the atoms it contains, and measuring the spectral lines emitted when the excited atoms return to lower energy levels.

[0018] (Bismuth composition on the catalyst surface relative to the entire catalyst) In the catalyst according to the present invention, when A is the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP 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. 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 amount of bismuth atoms present on the catalyst surface relative to the amount of bismuth atoms in the entire catalyst. When the catalyst's B / A ratio satisfies the above-mentioned range, the target product can be produced from the raw materials with high selectivity. The reason for this is not entirely clear, but the following reasons are possible: Bismuth plays a role as an active site for the reaction on the catalyst surface, and when the B / A ratio is 1.3 or higher, that is, when there is a sufficient amount of bismuth atoms on the catalyst surface, selective oxidation of the target product proceeds, improving the selectivity of the target product. Also, when the B / A ratio is 5 or lower, that is, when there is not an excess of bismuth atoms on the catalyst surface, sequential reactions from the target product are suppressed, and the decrease in the selectivity of the target product is suppressed. Of the above, the lower limit of the B / A value is preferably 1.5 or higher, more preferably 1.7 or higher, and even more preferably 1.9 or higher. The upper limit of the B / A value is preferably 4 or lower, and more preferably 3 or lower. The lower limit of the value of A is preferably 0.02 or higher, and more preferably 0.03 or higher. The upper limit of the value of A is preferably 0.1 or lower, and more preferably 0.09 or lower. The lower limit of the value of B is preferably 0.04 or higher, more preferably 0.06 or higher, and even more preferably 0.07 or higher. The upper limit of the value of B is preferably 0.2 or lower, more preferably 0.18 or lower, and even more preferably 0.16 or lower.

[0019] Methods for controlling the values ​​of A, B, and B / A mentioned above include adjusting the type and amount of molybdenum raw material used, the type and amount of bismuth raw material used, the stirring time, the heating time, and the heating temperature in the catalyst manufacturing method. Among these, in particular, by stirring for 20 to 90 minutes at a temperature 1 to 30°C lower than the boiling point of the solvent in step (ii), and stirring for 10 minutes to 10 hours at a temperature 2°C or more higher than the boiling point of the solvent in step (iii), the values ​​of A, B, and B / A can be controlled to a desired range.

[0020] In this invention, the value of A is determined by performing ICP emission spectrometry on the catalyst as described above and calculating the ratio of the amount of bismuth atoms to the amount of molybdenum atoms. The value of B is determined by performing X-ray photoelectron spectroscopy on the catalyst and calculating the ratio of the peak area of ​​bismuth atoms to the peak area of ​​molybdenum atoms. For example, a Quantera II (manufactured by ULVAC-PHI) can be used as the analytical instrument. The analytical conditions are as follows: X-ray: HP mode - monochromatic Al source, output: 300W, acquisition angle: 45°, and the X-ray beam diameter is 100 μmφ, scanning a range of 1400 μm linearly. X-ray photoelectron spectroscopy is a method for measuring the composition and chemical state of elements constituting the sample surface by irradiating the sample surface with X-rays and measuring the kinetic energy of photoelectrons emitted from the sample surface. Generally, information on elements present within a few nanometers of the sample surface can be obtained, so information on the composition and chemical state of the catalyst surface can be obtained.

[0021] (Density of catalyst) The catalyst density is not particularly limited, but from the viewpoint of improving catalyst durability, the lower limit is 0.2 g / cm³. 3 Preferably, it is 0.5 g / cm³ or more. 3 It is more preferable that the concentration be 1 g / cm³ or higher. 3 It is even more preferable that the above conditions are met. On the other hand, from the viewpoint of improving the selectivity of the target product, the upper limit is 50 g / cm³. 3 Preferably, it is 30 g / cm³ 3 More preferably, it is 20 g / cm³. 3 The following is even more preferable:

[0022] [Method for manufacturing catalysts] Another embodiment of the present invention is a method for producing a catalyst, comprising the following steps (i) to (v). The resulting catalyst preferably has a B / A ratio of 1.3 to 5. (i) A step of mixing at least molybdenum raw material and bismuth raw material with a solvent to obtain a slurry (Solution A). (ii) A step of stirring the above-mentioned 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). (iii) A step of stirring liquid B at a temperature 2°C or more higher than the temperature in step (ii) for 10 minutes to 10 hours to obtain a slurry (liquid C). (iv) A step of drying the C solution to obtain a dried product. (v) A step of obtaining a catalyst by calcining the dried material. Furthermore, the method for producing a catalyst according to the present invention may further include a molding step, which will be described later. The following provides a detailed explanation of each step.

[0023] (Step (i)) In step (i), at least molybdenum and bismuth raw materials are mixed with a solvent to obtain a slurry (Solution A). Solution A is prepared by mixing molybdenum and bismuth raw materials with a solvent. In addition, raw materials of each element included in formula (1) (hereinafter also referred to as catalyst raw materials) may be further mixed. The amount of catalyst raw materials used can be adjusted as appropriate to achieve the desired catalyst composition. The catalyst raw materials are not particularly limited, and nitrates, carbonates, bicarbonates, acetates, ammonium salts, sulfates, oxides, chlorides, hydroxides, halides, oxoacids, oxoates, etc. of each element can be used individually or in combination of two or more types.

[0024] 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 iron nitrate, iron hydroxide, and iron trioxide, with iron nitrate being preferred.

[0025] The solvent is not particularly limited as long as it can dissolve or disperse the catalyst raw materials, but it is preferable to contain at least water, more preferably 50% by mass or more of the total solvent is water, and even more preferably 80% by mass or more of the total solvent is water. Water alone may also be used. The solvent may also contain an organic solvent. The organic solvent is not particularly limited and includes alcohols, acetone, etc. The amount of solvent used is not particularly limited, but it is preferably 30 to 400 parts by mass per 100 parts by mass of the total catalyst raw materials.

[0026] Step (i) preferably includes the following steps (i-1) and (i-2).

[0027] (i-1) A step of preparing a solution or slurry (A1 solution) containing molybdenum, bismuth, and elements X and Y in formula (1), and a solution or slurry (A2 solution) containing iron and element M in formula (1). (ii-2) A step of preparing solution A by mixing solution A1 and solution A2. The following provides a detailed explanation of each step.

[0028] <Process (i-1)> In step (i-1), a solution or slurry (A1 solution) containing molybdenum, bismuth, and elements X and Y of formula (1), and a solution containing iron and element M of formula (1) are used. Alternatively, prepare a slurry (Solution A2). Note that the order in which Solutions A1 and A2 are prepared is not limited, and Solutions A1 and A2 may be prepared simultaneously. The amount of each catalyst material used is preferably adjusted so that the resulting catalyst has the composition represented by formula (1) above. The amount of solvent used is not particularly limited, but it is preferable that the amount of solution A1 be 70 to 400 parts by mass per 100 parts by mass of the total catalyst raw materials. It is also preferable that the amount of solution A2 be 30 to 230 parts by mass per 100 parts by mass of the total catalyst raw materials.

[0029] <Process (i-2)> In step (i-2), solution A is prepared by mixing solution A1 and solution A2 obtained in step (i-1).

[0030] (Step (ii)) In step (ii), the solution 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 (solution B). For example, if water is used as the solvent in step (i), the boiling point of water is 100°C, so in step (ii), solution A is stirred at 70 to 99°C. If multiple solvents with different boiling points are used in step (i), the mixture is stirred at a temperature 1 to 30°C lower than the boiling point of the solvent with the largest mass percentage. In step (ii), when dissolving the catalyst raw materials in the solvent, the solubility of the bismuth raw material is adjusted to a constant level by setting the temperature and stirring time to the above-mentioned conditions. This is thought to ensure that when the bismuth molybdate composite oxide layer is formed in step (iii) described later, the bismuth, which acts as the active site, precipitates suitably on the surface, and a catalyst with a B / A ratio of 1.5 to 5 can be obtained. If the temperature in step (ii) is lower than specified, or the stirring time is shorter than specified, the solubility of the bismuth raw material decreases, and the B / A ratio of the resulting catalyst tends to be less than 1.5. On the other hand, if the temperature in step (ii) is higher than specified, or the stirring time is longer than specified, the solubility of the molybdenum and bismuth raw materials increases, and the B / A ratio of the resulting catalyst tends to be greater than 5.

[0031] The upper limit of the temperature when stirring solution A is preferably 3°C or more lower than the boiling point of the solvent, and 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 even more preferably 10°C or less lower.

[0032] The lower limit of the stirring time within the above temperature range is preferably 30 minutes or more, and more preferably 40 minutes or more. The upper limit is preferably 80 minutes or less, and more preferably 70 minutes or less.

[0033] (Step (iii)) In step (iii), liquid B obtained in step (ii) is stirred for 10 minutes to 10 hours at a temperature at least 2°C higher than the temperature in step (ii) to obtain slurry (liquid C). In step (iii), a bismuth molybdate composite oxide layer is formed. At this time, by stirring solution B, whose bismuth solubility was adjusted in step (ii), at the above temperature for the above time, it is considered that bismuth, which serves as the active site, is suitably precipitated on the surface when forming the bismuth molybdate composite oxide layer, and a catalyst with a B / A ratio of 1.5 to 5 can be obtained. If the temperature in step (iii) is lower than specified, or the stirring time is shorter than specified, the precipitation of bismuth on the surface is not promoted, and the B / A ratio of the resulting catalyst tends to be less than 1.5. On the other hand, if the temperature in step (iii) is higher than specified, or the stirring time is longer than specified, the precipitation of bismuth on the surface becomes excessive, and the B / A ratio of the resulting catalyst tends to be greater than 5.

[0034] The lower limit of the temperature when stirring solution B is preferably 3°C or more higher than the temperature in step (ii). It is more preferable that the temperature be 5°C or higher, even more preferable that it be 6°C or higher, and particularly preferable that it be 8°C or higher. Furthermore, the upper limit is preferably 20°C or less higher than the temperature in step (ii), and more preferably 10°C or less higher. Furthermore, the temperature at which solution B is stirred is preferably 1 to 20°C higher than the boiling point of the solvent. For example, if water is used as the solvent in step (i), the boiling point of water is 100°C, so it is preferable to stir solution B at 101 to 120°C in step (iii). The lower limit of the temperature at which solution B is stirred is more preferably 2°C or more higher than the boiling point of the solvent, and even more preferably 3°C or more higher. The upper limit is more preferably 10°C or less higher than the boiling point of the solvent, and even more preferably 5°C or less higher.

[0035] The lower limit of the stirring time within the above temperature range is preferably 20 minutes or more, more preferably 30 minutes or more, even more preferably 60 minutes or more, particularly preferably 90 minutes or more, and most preferably 2 hours or more. The upper limit is preferably 9 hours or less, and more preferably 8 hours or less.

[0036] (Step (iv)) In step (iv), the liquid C obtained in step (iii) is dried to obtain a dried product. Drying of liquid C can be performed using known methods such as drum drying, airflow drying, evaporation to dryness, or spray drying. The drying temperature is preferably 120 to 500°C, with a lower limit of 140°C or higher and a higher limit of 350°C or lower. Drying is preferably performed so that the moisture content of the resulting dried product is 0.1 to 4.5% by mass. These conditions can be appropriately selected depending on the desired shape and size of the catalyst. Drying liquid C suppresses adhesion of the dried product and improves yield.

[0037] (Process (v)) In step (v), the dried material obtained in step (iv) is calcined to obtain a catalyst. Although calcination can be performed after obtaining a molded product by carrying out the molding process described later, it is preferable to perform calcination before the molding process from the viewpoint of catalyst strength. In this invention, the catalyst is collectively referred to as such, including the product after calcination and molding. The firing process may be performed only once, or it may be carried out in multiple stages in conjunction with the molding process described later. For example, a primary firing may be performed first, the molding process described later may be carried out on the obtained primary firing product, and then a secondary firing may be performed on the resulting molded product. Alternatively, both primary and secondary firing may be performed, and then the molding process may be carried out on the resulting catalyst. The calcination process is preferably carried out under the flow of an oxygen-containing gas such as air, or under the flow of an inert gas. An "inert gas" refers to a gas that does not reduce catalytic activity, and examples include nitrogen, carbon dioxide, helium, and argon.

[0038] The firing temperature is preferably 200 to 700°C. The lower limit of the firing temperature is more preferably 300°C or higher, while the upper limit is more preferably 500°C or lower, and even more preferably 450°C or lower. The firing time is preferably 0.5 to 40 hours, with a lower limit of 1 hour or more being more preferable. The firing time refers to the time from when the predetermined firing temperature is reached until that temperature is maintained.

[0039] Among the above, it is preferable to perform primary firing on the dried material, followed by molding, and then perform secondary firing on the resulting molded product. In this case, the primary firing temperature is preferably 200 to 600°C, with a lower limit of 250°C or higher and a higher limit of 450°C or lower. The primary firing time is preferably 0.5 to 5 hours from the viewpoint of improving the selectivity of the target product. The type and method of the firing furnace used for primary firing are not particularly limited, and for example, a box-type firing furnace, a tunnel-type firing furnace, etc., may be used to fire the dried material or molded material in a fixed state. Alternatively, a rotary kiln or the like may be used to fire the dried material or molded material while it is flowing.

[0040] The firing temperature for the secondary firing is preferably 300 to 700°C, with a lower limit of 400°C or higher and a higher limit of 600°C or lower. The firing time for the secondary firing is preferably 10 minutes to 10 hours, with a lower limit of 1 hour or higher, from the viewpoint of improving the selectivity of the target product. The type of firing apparatus and method for the secondary firing are not particularly limited, and for example, a box-type firing furnace, a tunnel-type firing furnace, etc., may be used to fire the molded product or the primary fired product in a fixed state. Alternatively, a rotary kiln or the like may be used to fire the molded product or the primary fired product while it is flowing.

[0041] (molding process) In the molding process, the dried product obtained in step (iv) or the fired 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 applied. Examples include tablet molding, extrusion molding, pressure molding, and rolling granulation. During molding, conventionally known additives, such as organic compounds like polyvinyl alcohol and carboxymethylcellulose, may be added. Furthermore, inorganic compounds such as graphite and diatomaceous earth, and inorganic fibers such as glass fibers, ceramic fibers, and carbon fibers may also be added.

[0042] The shape of the molded product is not particularly limited, and any shape can be used, such as spherical, cylindrical, ring-shaped, star-shaped, or granular after crushing and classification. Among these, spherical, cylindrical, and ring-shaped are preferred from the viewpoint of mechanical strength. The size of the molded product is not particularly limited, but 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 sphere's diameter is more preferably 0.5 mm or more, even more preferably 1 mm or more, and particularly preferably 3 mm or more. The upper limit of the sphere's diameter is more preferably 8 mm or less, and even more preferably 6 mm or less. In the case of a ring-shaped or cylindrical shape, the diameter and height of the base circle of the ring or cylinder are both preferably 0.1 to 10 mm. The lower limit of the diameter and height is more preferably 0.5 mm or more, even more preferably 1 mm or more, and particularly preferably 3 mm or more. The upper limit of the diameter and height is more preferably 8 mm or less, and even more preferably 6 mm or less. In the case of other shapes, the distance between the two furthest points within the three-dimensional structure of 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, even more preferably 1 mm or more, and particularly preferably 3 mm or more. The upper limit of the length between the two points is more preferably 8 mm or less, and even more preferably 6 mm or less. This improves the selectivity of the target product and the catalyst lifetime.

[0043] The external surface area of ​​the molded product is not particularly limited, but from the viewpoint of stably producing the target product over a long period of time, the lower limit is 0.01 cm². 2 The above is preferable, and 0.05 cm 2 The above is more preferable, 0.1 cm 2 The above is even more preferable. On the other hand, from the viewpoint of improving the selectivity of the target product, the upper limit is 4 cm. 2 The following is preferable: 3 cm 2 The following is more preferable, 2cm 2 The following are even more preferable.

[0044] The volume of the molded product is not particularly limited, but from the viewpoint of stably producing the target product over a long period of time, the lower limit is 0.0002 cm³. 3 The above is preferable, and 0.002 cm 3 The above is more preferable, 0.02 cm 3The above is even more preferable. On the other hand, from the viewpoint of improving the selectivity of the target product, the upper limit is 5 cm. 3 The following is preferable: 1 cm 3 More preferably, 0.5 cm 3 The following are even more preferable.

[0045] The mass of the molded product is not particularly limited, but from the viewpoint of stably producing the target product over a long period of time, the lower limit is preferably 0.002 g / piece or more, more preferably 0.01 g / piece or more, and even more preferably 0.05 g / piece or more. On the other hand, from the viewpoint of improving the selectivity of the target product, the upper limit is preferably 0.5 g / piece or less, more preferably 0.3 g / piece or less, and even more preferably 0.2 g / piece or less.

[0046] The bulk density of the molded product is not particularly limited, but it is important to ensure that the target product can be produced stably over a long period of time. From this perspective, the lower limit is 0.2 g / cm³. 3 The above is preferable, 0.3 g / cm³ 3 The above is more preferable, 0.4 g / cm³ 3 The above is even more preferable. On the other hand, from the viewpoint of improving the selectivity of the target product, the upper limit is 1 g / cm³. 3 The following is preferable: 0.9 g / cm³ 3 The following is more preferable: 0.8 g / cm³ 3 The following is even more preferable. Note that the bulk density of the molded product refers to the value calculated from the total mass of the molded product when it is filled into a 100 ml graduated cylinder, according to the method in accordance with JIS-K 7365.

[0047] The resulting molded product may be supported on a carrier. Examples of carriers that can be used for this purpose include silica, alumina, silica-alumina, magnesia, titania, and silicon carbide. The molded product can also be used after being diluted with an inert substance such as silica, alumina, silica-alumina, magnesia, titania, or silicon carbide. In this manner, a catalyst can be manufactured.

[0048] [Method for producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids] In the method for producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids according to the present invention, the corresponding α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids are produced from alkenes, alcohols, or ethers using the catalyst according to the present invention or a catalyst produced by the production method according to the present invention.

[0049] Examples of the aforementioned alkenes include propylene and isobutylene. Examples of the aforementioned alcohols include t-butyl alcohol and isobutyl alcohol. Examples of the aforementioned ethers include methyl t-butyl ether. By oxidizing these raw material organic compounds, the corresponding α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid can be produced. For example, if the raw material organic compound is propylene, the corresponding α,β-unsaturated aldehyde is acrolein and the corresponding α,β-unsaturated carboxylic acid is acrylic acid. If the raw material organic compound is isobutylene, t-butyl alcohol, isobutyl alcohol, or methyl t-butyl ether, the corresponding α,β-unsaturated aldehyde is methacrolein and the corresponding α,β-unsaturated carboxylic acid is methacrylic acid. From the viewpoint of selectivity of the target product, it is preferable that the α,β-unsaturated aldehyde and α,β-unsaturated carboxylic acid are methacrolein and methacrylic acid, respectively.

[0050] The method for producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids according to the present invention can be carried out by bringing a catalyst produced by the present invention or the production method according to the present invention into contact with a raw material gas containing the raw material organic compound and oxygen in a reactor.

[0051] The reactor is not particularly limited, but it is preferable to use a tubular reactor equipped with reaction tubes filled with catalyst, and industrially, it is more preferable to use a multi-tube reactor equipped with multiple such reaction tubes. The catalyst layer in the reactor may be a single layer, or multiple catalysts with different levels of activity may be packed into multiple layers. In addition, the catalyst may be diluted with an inert support before packing in order to control its activity.

[0052] The concentration of the raw material organic compound in the raw material gas is preferably 1 to 20% by volume, with a lower limit of 3% by volume or more and a higher limit of 10% by volume or less. The raw material organic compound may contain small amounts of impurities that do not substantially affect this reaction, such as lower saturated alkanes.

[0053] The oxygen concentration in the raw material gas is preferably 0.1 to 5 moles per mole of raw material organic compound, with a lower limit of 0.5 moles or more and a higher upper limit of 3 moles or less. From an economic standpoint, air is preferred as the oxygen source for the raw material gas. If necessary, an oxygen-enriched gas may be used by mixing pure oxygen with air or the like. From an economic standpoint, the raw material gas was diluted with an inert gas such as nitrogen or carbon dioxide. This may also be done. Furthermore, water vapor may be added to the raw material gas. By carrying out 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 concentration of water vapor in the raw material gas is preferably 0.1 to 50% by volume, with a lower limit of 1% by volume or more and a higher upper limit of 40% by volume or less.

[0054] The reaction pressure is preferably 0 to 1 MPa (G). Here, "(G)" is gauge pressure, and 0 MPa (G) means that the reaction pressure is atmospheric pressure. The reaction temperature is preferably 200 to 450°C, with a lower limit of 250°C or higher and a higher limit of 400°C or lower. 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 more, while the upper limit is more preferably 10 seconds or less, and even more preferably 5 seconds or less.

[0055] By manufacturing in the manner described above, α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids corresponding to the raw material organic compounds used can be obtained with high selectivity.

[0056] [Method for producing α,β-unsaturated carboxylic acids] In the method for producing α,β-unsaturated carboxylic acids according to the present invention, the corresponding α,β-unsaturated carboxylic acids are produced from α,β-unsaturated aldehydes produced by the production method according to the present invention.

[0057] Examples of the α,β-unsaturated aldehyde include (meth)acrolein, crotonaldehyde (β-methylacrolein), and cinnamaldehyde (β-phenylacrolein). The α,β-unsaturated carboxylic acid produced is an α,β-unsaturated carboxylic acid in which the aldehyde group of the α,β-unsaturated aldehyde is changed to a carboxyl group. Specifically, when the α,β-unsaturated aldehyde is (meth)acrolein, (meth)acrylic acid is obtained. From the viewpoint of selectivity of the target product, the α,β-unsaturated aldehyde and α,β-unsaturated carboxylic acid are preferably (meth)acrolein and (meth)acrylic acid, respectively, and more preferably metacrolein and methacrylic acid. Note that "(meth)acrolein" refers to acrolein and metacrolein, and "(meth)acrylic acid" refers to acrylic acid and methacrylic acid.

[0058] The method for producing α,β-unsaturated carboxylic acids according to the present invention can be carried out by contacting a catalyst according to the present invention or a catalyst produced by the production method according to the present invention with a raw material gas containing α,β-unsaturated aldehyde and oxygen in a reactor. It is preferable to use a heteropoly acid catalyst as the catalyst. As the reactor, the same type of reactor as described above for the production of α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acids can be used. The catalyst layer in the reactor may be a single layer, or multiple catalysts with different activities may be packed into multiple layers. Furthermore, the catalyst may be diluted with an inert support before packing in order to control its activity.

[0059] The concentration of α,β-unsaturated aldehyde in the raw material gas is preferably 1 to 20% by volume, with a lower limit of 3% or more by volume and a higher limit of 10% or less by volume. The α,β-unsaturated aldehyde may contain small amounts of impurities such as lower saturated aldehydes that do not substantially affect this reaction.

[0060] The oxygen concentration in the raw material gas is preferably 0.4 to 4 moles per mole of α,β-unsaturated aldehyde, with a lower limit of 0.5 moles or more and a higher upper limit of 3 moles or less. From an economic standpoint, air is preferred as the oxygen source for the raw material gas. If necessary, an oxygen-enriched gas may be used by mixing pure oxygen with air or the like.

[0061] From an economic standpoint, the raw material gas may be diluted with an inert gas such as nitrogen or carbon dioxide. Furthermore, water vapor may be added to the raw material gas. By carrying out the reaction in the presence of water vapor, α,β-unsaturated carboxylic acids can be obtained with higher selectivity. The concentration of water vapor in the raw material gas is preferably 0.1 to 50% by volume, with a lower limit of 1% by volume or more and a higher upper limit of 40% by volume or less.

[0062] The reaction pressure is preferably 0 to 1 MPa (G). The reaction temperature is preferably 200 to 450°C, with a lower limit of 250°C or higher and a higher limit of 400°C or lower. 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 more, while the upper limit is more preferably 10 seconds or less, and even more preferably 5 seconds or less.

[0063] [Method for producing α,β-unsaturated carboxylic acid esters] In the method for producing α,β-unsaturated carboxylic acid esters according to the present invention, the α,β-unsaturated carboxylic acid produced by the production method according to the present invention is esterified. The alcohol to be reacted with the α,β-unsaturated carboxylic acid is not particularly limited and includes methanol, ethanol, propanol, isopropanol, butanol, isobutanol, etc. Examples of the resulting α,β-unsaturated carboxylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, etc. 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. [Examples]

[0064] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the examples and comparative examples, "parts" means parts by mass.

[0065] (Composition of the catalyst) The overall composition of the catalyst was determined by analyzing the components of the catalyst dissolved in ammonia water using ICP emission spectrometry. An ICP Optima 8300 (Perkin Elmer) was used as the analytical instrument, with an output of 1300W, plasma gas flow rate of 10 L / min, auxiliary gas flow rate of 0.2 L / min, nebulizer gas flow rate of 0.55 L / min, and a segmented array CCD detector. Furthermore, the value of A was calculated from the ratio of the amount of bismuth atoms to the amount of molybdenum atoms in the overall composition of the obtained catalyst.

[0066] (X-ray photoelectron spectroscopy analysis of catalysts) The value of B was determined 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. A Quantera II (ULVAC-PHI) was used as the analyzer, with an X-ray source in HP mode, output power of 300W, and acquisition angle of 45°. The X-ray beam diameter was 100 μmφ and a range of 1400 μm was scanned linearly.

[0067] (Response evaluation) The reaction evaluation of the catalysts in the examples and comparative examples was carried out using the production of methacrolein and methacrylic acid by oxidation of isobutylene as an example. The analysis of the source gas and products in the reaction evaluation was performed using the gas chromatography described below. Analysis of methacrolein: Shimadzu GC-2014, column: QUADREX 007-CW 20m x 0.32mm, film thickness: 3μm Analysis of methacrylic acid: Shimadzu GC-2014, column: J&W DB-FFA P, 30m x 0.32mm, film thickness 1.00μm The total selectivity of the generated methacrolein and methacrylic acid was calculated from the gas chromatography results using the following formula. Total selectivity (%) for methacrolein and methacrylic acid = (P1 + P2) / M1 × 100 In the above formula, M1 is the number of moles of isobutylene that 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.

[0068] <Example 1> Solution A1 was obtained 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 with 2,000 parts by mass of pure water at 60°C as a solvent. Separately from Solution A1, Solution A2 was obtained by mixing 200.2 parts by mass of iron(III) nitrate nonahydrate and 515.1 parts by mass of cobalt(II) nitrate hexahydrate with 1,000 parts by mass of pure water. Solution A1 and Solution A2 were then mixed to obtain Solution A.

[0069] The obtained solution A was heated to 95°C, and while maintaining the liquid temperature at 95°C, it was stirred for 1 hour to obtain solution B. The obtained solution B was heated to 103°C, and while maintaining the liquid temperature at 103°C, it was stirred for 3 hours to obtain solution C. The obtained liquid C was dried in a spray dryer to obtain a dried product. The dried product was in a good drying state with no adhesion to the inner wall surface of the spray dryer. The obtained dried material was first calcined at 300°C for 1 hour in an air atmosphere, and then pulverized. Next, the pulverized, calcined dried material was pressure-molded and then crushed to obtain crushed particles. These crushed particles were then classified, and the particles that passed through a sieve with a mesh size of 2.36 mm but did not pass through a sieve with a mesh size of 0.71 mm were collected. The collected crushed particles were then secondarily calcined at 500°C for 3 hours in an air atmosphere to obtain a catalyst. The oxygen-free composition of the resulting catalyst is Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 S 0.6 Cs 0.6 Furthermore, ICP emission spectrometry and X-ray photoelectron spectroscopy were performed on the catalyst. The calculated values ​​of A, B, and B / A are shown in Table 1.

[0070] Next, the obtained catalyst was packed into a stainless steel reaction tube to form a catalyst layer, and the oxidation reaction of isobutylene was carried out under the following conditions. The results are shown in Table 1. Raw material gas composition: Isobutylene 5% by volume, oxygen 12% by volume, water vapor 10% by volume, and nitrogen 73% by volume. Reaction temperature: 340℃ Contact time between source gas and catalyst: 2.7 seconds

[0071] <Example 2> Solution A1 was prepared in the same manner as in Example 1, except that it contained 24.8 parts by mass of antimony trioxide. Separately from Solution A1, Solution A2 was prepared in the same manner as in Example 1. Then, Solution A1 and Solution A2 were mixed to obtain Solution A. The obtained solution A was heated to 95°C, and while maintaining the liquid temperature at 95°C, it was stirred for 1 hour to obtain solution B. The obtained solution B was heated to 103°C and stirred for 5 hours while maintaining the liquid temperature at 103°C to obtain solution C. The obtained liquid C was dried in a spray dryer to obtain a dried product. The dried product was in a good drying state with no adhesion to the inner wall surface of the spray dryer. The resulting dried product was subjected to primary calcination, molding, and secondary calcination in the same manner as in Example 1, and the catalyst I obtained it. The oxygen-free composition of the resulting catalyst is Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 S 0.72 Cs 0.6 Furthermore, ICP emission spectrometry and X-ray photoelectron spectroscopy were performed on the catalyst. The calculated values ​​of A, B, and B / A are shown in Table 1. Next, the reaction was evaluated using the obtained catalyst in the same manner as in Example 1. The results are shown in Table 1.

[0072] <Example 3> Solution A1 was prepared in the same manner as in Example 1, except that it contained 15.5 parts by mass of antimony trioxide. In addition, solution A2 was prepared separately from solution A1 in the same manner as in Example 1. Then, solution A2 was mixed with solution A1 to obtain solution A. The obtained solution was heated to 95°C and stirred for 1 hour while maintaining the temperature at 95°C to obtain solution B. The obtained solution B was heated to 103°C and stirred for 7 hours while maintaining the liquid temperature at 103°C to obtain solution C. The obtained liquid C was dried in a spray dryer to obtain a dried product. The dried product was in a good drying state with no adhesion to the inner wall surface of the spray dryer. The obtained dried material was subjected to primary calcination, molding, and secondary calcination in the same manner as in Example 1 to obtain a catalyst. The oxygen-free composition of the resulting catalyst is Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 S 0.45 Cs 0.6Furthermore, ICP emission spectrometry and X-ray photoelectron spectroscopy were performed on the catalyst. The calculated values ​​of A, B, and B / A are shown in Table 1. Next, the reaction was evaluated using the obtained catalyst in the same manner as in Example 1. The results are shown in Table 1.

[0073] <Comparative Example 1> Solution B was obtained using the same method as in Example 1. The obtained liquid B was dried in a spray dryer to obtain a dried product. In other words, the dried product was obtained by drying liquid B without performing step (iii). The dried product was in a good drying state with no adhesion to the inner wall surface of the spray dryer. The obtained dried material was subjected to primary calcination, molding, and secondary calcination in the same manner as in Example 1 to obtain a catalyst. The oxygen-free composition of the resulting catalyst is Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 S 0.6 Cs 0.6 Furthermore, ICP emission spectrometry and X-ray photoelectron spectroscopy were performed on the catalyst. The calculated values ​​of A, B, and B / A are shown in Table 1. Next, the reaction was evaluated using the obtained catalyst in the same manner as in Example 1. The results are shown in Table 1.

[0074] <Comparative Example 2> Solution A was obtained using the same method as in Example 1. The obtained solution A was heated to 95°C and stirred for 2 hours while maintaining the liquid temperature at 95°C. In other words, in step (ii), the mixture was stirred for a longer time than 90 minutes to obtain solution B'. The obtained solution B' was heated to 100°C, and while maintaining the temperature at 100°C, it was stirred for 1 hour to obtain solution C. The obtained liquid C was dried in a spray dryer to obtain a dried product. The dried product was in a good drying state with no adhesion to the inner wall surface of the spray dryer. The obtained dried material was subjected to primary calcination, molding, and secondary calcination in the same manner as in Example 1 to obtain a catalyst. The oxygen-free composition of the resulting catalyst is Mo 12 Bi0.7 Fe 2.1 Co 7.5 W 0.2 S 0.6 Cs 0.6 Furthermore, ICP emission spectrometry and X-ray photoelectron spectroscopy were performed on the catalyst. The calculated values ​​of A, B, and B / A are shown in Table 1. Next, the reaction was evaluated using the obtained catalyst in the same manner as in Example 1. The results are shown in Table 1.

[0075] [Table 1]

[0076] As shown in Table 1, Examples 1-3, which used catalysts with a B / A ratio within the specified range, showed good overall selectivity for methacrolein and methacrylic acid. Furthermore, methacrylic acid can be obtained by oxidizing the methacrolein obtained in this embodiment, and methacrylic acid ester can be obtained by esterifying the methacrylic acid. [Industrial applicability]

[0077] According to the present invention, a catalyst can be provided that can produce target products such as α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids with high selectivity, and is industrially useful.

Claims

1. A catalyst used in producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids from alkenes, alcohols, or ethers containing at least molybdenum, bismuth, and iron, When A is the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP (inductively coupled radio frequency 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, then B / A is between 1.5 and 4. The value of A is between 0.02 and 0.

1. A catalyst whose catalytic composition is represented by the following formula (1). Mo ａ Yes ｂ Fe ｃ M ｄ X e Y ｆ Yes ｇ Oh ｈ (1) (In formula (1) above, Mo, Bi, Fe, Si, and O represent molybdenum, bismuth, iron, silicon, and oxygen, respectively. M represents at least one element selected from the group consisting of cobalt and nickel. X represents at least one element selected from the group consisting of 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 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 to 3, c = 0.01 to 8, d = 0.01 to 12, e = 0.1 to 8, f = 0.001 to 2, g = 0 to 20, and h is the previous This is the ratio of oxygen atoms required to satisfy the valence of each component.

2. A catalyst used in producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids from alkenes, alcohols, or ethers containing at least molybdenum, bismuth, and iron, When A is the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP (inductively coupled radio frequency 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, then B / A is between 1.5 and 4. The value of B is between 0.04 and 0.

2. A catalyst whose catalytic composition is represented by the following formula (1). Mo ａ Yes ｂ Fe ｃ M ｄ X e Y ｆ Yes ｇ Oh ｈ (1) (In formula (1) above, Mo, Bi, Fe, Si, and O represent molybdenum, bismuth, iron, silicon, and oxygen, respectively. M represents at least one element selected from the group consisting of cobalt and nickel. X represents at least one element selected from the group consisting of 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 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 to 3, c = 0.01 to 8, d = 0.01 to 12, e = 0.1 to 8, f = 0.001 to 2, g = 0 to 20, and h is the previous This is the ratio of oxygen atoms required to satisfy the valence of each component.

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

4. Density is 0.2 g / cm³ ３ Above, 50g / cm ３ The catalyst according to claim 1 or 2, which is as follows:

5. A molded article comprising the catalyst according to claim 1 or 2.

6. External surface area is 0.01cm ２ More than 4cm ２ The molded article according to claim 5, which is as follows:

7. The packing bulk density is 0.2 g / cm³. ３ Above, 1g / cm ３ The molded article according to claim 5, which is as follows:

8. A method for producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids from alkenes, alcohols, or ethers using a catalyst according to any one of claims 1 to 4.

9. A method for producing α,β-unsaturated aldehydes and / or α,β-unsaturated carboxylic acids from alkenes, alcohols, or ethers, using a molded article according to any one of claims 5 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 manufacturing method described in claim 8 or 9.

11. 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 manufacturing method described in any one of claims 8 to 10.

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