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

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 methods for producing an α,β-unsaturated aldehyde, an α,β-unsaturated carboxylic acid, and an α,β-unsaturated carboxylic acid ester.

Background Art

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

[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 method for producing a catalyst used for producing a corresponding unsaturated aldehyde and unsaturated carboxylic acid from an olefin. Further, Patent Document 2 describes an example in which a catalyst for synthesizing an unsaturated aldehyde and an unsaturated carboxylic acid excellent in catalytic activity and selectivity can be provided by comprising particles of a composite oxide containing at least molybdenum, iron and cobalt and the atomic ratios in the bulk composition and surface composition of the particles satisfying specific conditions.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, according to the studies by the inventors, it has been found that the catalysts described in Patent Documents 1 and 2 do not necessarily have sufficient performance and may produce many by-products. Since these problems affect the selectivity of target products such as α,β-unsaturated aldehydes and α,β-unsaturated carboxylic acids, there is an actual need for further improvement in the performance of the catalysts. Therefore, from the perspective of further improving the catalyst performance, it is required to control the physical properties of the catalyst. The present invention has been made in view of the above circumstances, and an object thereof is to provide a catalyst having a high selectivity for target products such as α,β-unsaturated aldehydes and α,β-unsaturated carboxylic acids.

Means for Solving the Problems

[0006] The inventors of the present invention have conducted intensive studies to achieve the above object. As a result, it has been found that in a catalyst containing at least molybdenum and bismuth, by adjusting the bismuth composition on the catalyst surface with respect to the whole catalyst, a target product can be produced with high selectivity. That is, the present invention includes the following.

[0007] [1]: A catalyst containing at least molybdenum and bismuth, when the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP (Inductively Coupled Plasma) emission spectrometry 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, a catalyst in which B / A is 1 .3 to 5. [2]: The catalyst according to [1], wherein the value of B / A is 1.5 to 4. [3]: The catalyst according to [1] or [2], wherein the value of B / A is 1.7 to 3. [4]: The catalyst according to any one of [1] to [3], wherein the value of A is 0.02 to 0.1. [5]: The catalyst according to any one of [1] to [4], wherein the value of B is 0.04 to 0.2. [6]: The catalyst according to any one 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], which is used for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid from an alkene, an alcohol or an ether. [8]: A catalyst according to any one of [1] to [7], wherein the catalyst composition is 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 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 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 the respective elements. 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 oxygen atom ratio necessary to satisfy the valence of the above respective components.) [9]: A method for producing a catalyst containing at least molybdenum and bismuth, the method for producing a catalyst including 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 (solution A); (ii) A step of stirring the solution 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 (solution B); (iii) A step of stirring the solution 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 (solution C); (iv) A step of drying the solution C to obtain a dried product; (v) A step of firing 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 total 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 is used for producing a catalyst used in the production of α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid from alkene, alcohol or 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 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 the respective elements. 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 oxygen atom ratio necessary to satisfy the valence of the respective components.) (.) ​

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

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

[14] .

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

[15] or

[16] .

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

[15] to

[17] . [Advantages of the Invention]

[0008] According to the present invention, a catalyst with a high selectivity for the target product can be provided. [Embodiments for Carrying Out the Invention]

[0009] Hereinafter, embodiments of the present invention will be described below, but the present invention is not limited thereto. In addition, the description of "XX or more and YY or less" or "XX to YY" representing a numerical range means a numerical range including the lower limit and the upper limit which are the endpoints, unless otherwise specified. When the numerical ranges are described stepwise, the upper and lower limits of each numerical range can be arbitrarily combined.

[0010] [Catalyst] The catalyst according to the present invention is a catalyst containing at least molybdenum and bismuth. When the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by 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, 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. From the viewpoint of the selectivity of the target product, the catalyst according to the present invention is preferably an oxidation catalyst, and more preferably a catalyst used in the production of α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid. Specifically, it is preferably a catalyst for producing α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid from alkene, alcohol or ether. Note that "producing α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid" means that either one of α,β-unsaturated aldehyde and α,β-unsaturated carboxylic acid may be produced, or both may be produced.

[0011] (Composition of the catalyst) The catalyst according to the present invention contains at least molybdenum and bismuth, and preferably has a composition represented by the following formula (1). Note that the catalyst component may contain a small amount of an element not described in the following 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 is zinc, chromium, lead, manganese, calcium, magnesium, nio It represents at least one element selected from the group consisting of Br, Ag, Ba, Sn, Ta, W, Sb, P, B, S, Se, Te, Ce, and Ti. Y represents at least one element selected from the group consisting of Cs, Li, Na, K, Rb, and Tl. a, b, c, d, e, f, g, and h represent the atomic ratios of the respective elements. 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 oxygen atom ratio necessary to satisfy the valences of the respective components. It is the oxygen atom ratio necessary to satisfy.

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

[0013] The catalyst contains molybdenum, bismuth, and optionally iron, and may contain the M element, X element, and Y element in the formula (1) as other elements other than these elements. Among other elements, it is preferable to contain the M element, and it is more preferable to further contain the Y element.

[0014] 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, still more preferably 1 or more, and particularly preferably 3 or more. 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, still more preferably 0.5 or more. 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, still more preferably 0.2 or more. The upper limit is preferably 1.8 or less, more preferably 1.6 or less, still more preferably 1.4 or less.

[0015] The catalyst may also have a carrier for supporting the above elements. The carrier is not particularly limited, and examples thereof include silica, alumina, silica-alumina, magnesia, titania, silicon carbide, and the like. Among these, when a carrier is used, silica is preferred as the carrier to prevent the reaction of the carrier itself. In the present invention, when a carrier is used in the catalyst, the carrier is also regarded as part of the catalyst.

[0016] 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, still more preferably 10 or less.

[0017] The composition of the catalyst shall be the value determined by analyzing the components obtained by dissolving the catalyst in aqueous ammonia by ICP emission spectrometry. As the analyzer, for example, ICP Optima 8300 (manufactured by Perkin Elmer) can be used. The analysis conditions are as follows: output: 1300 W, plasma gas flow rate: 10 L / min, auxiliary gas flow rate: 0.2 L / min, nebulizer gas flow rate: 0.55 L / min, detector: segmented array type CCD. ICP emission spectrometry is a method of measuring the spectral lines emitted when the atoms contained in a sample are excited by externally applying the energy of a plasma and the excited atoms return to a lower energy level.

[0018] (Bismuth composition of the catalyst surface with respect to the whole catalyst) For the catalyst according to the present invention, when the ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated from ICP emission spectrometry 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, 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 whole catalyst, and B represents the ratio of the amount of bismuth atoms to the amount of molybdenum atoms on the catalyst surface. That is, B / A represents the amount of bismuth atoms present on the catalyst surface relative to the amount of bismuth atoms in the whole catalyst. When B / A of the catalyst satisfies the above range, the target product can be produced from the raw material with high selectivity. The reason for this is not clear, but the following reasons are considered. Bismuth plays a role as an active site for the reaction on the catalyst surface. When B / A is 1.3 or more, that is, when the amount of bismuth atoms present on the catalyst surface is sufficient, the selective oxidation reaction to the target product proceeds, and the selectivity of the target product is improved. Also, when B / A is 5 or less, that is, when there is no excessive amount of bismuth atoms on the catalyst surface, the sequential reaction from the target product is suppressed, and it is considered that the decrease in the selectivity of the target product is suppressed. Among the above, the lower limit of the value of B / A is preferably 1.5 or more, more preferably 1.7 or more, and even more preferably 1.9 or more. Also, the upper limit of the value of B / A is preferably 4 or less, more preferably 3 or less. The lower limit of the value of A is preferably 0.02 or more, more preferably 0.03 or more. Also, the upper limit of the value of A is preferably 0.1 or less, more preferably 0.09 or less. 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. Also, 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.

[0019] As a method for controlling the values of A, B, and B / A, in the method for producing the catalyst, there are methods such as adjusting the type and amount of molybdenum raw material, the type and amount of bismuth raw material, stirring time, heating time, heating temperature, and the like. Among these, particularly in step (ii) described later, stirring is performed at a temperature 1 to 30 °C lower than the boiling point of the solvent for 20 to 90 minutes, and in step (iii), stirring is performed at a temperature 2 °C or higher than the boiling point of the solvent for 10 minutes to 10 hours, whereby the values of A, B, and B / A can be controlled within a desired range.

[0020] In the present invention, the value of A is determined by performing ICP emission analysis 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 analysis on the catalyst and calculating the ratio of the peak area of bismuth atoms to the peak area of molybdenum atoms. As the analyzer, for example, QuanteraII (manufactured by ULVAC-PHI, Inc.) can be used. The analysis conditions are as follows: X-ray: HP mode - monochromatic Al light source, output: 300 W, capture angle: 45°, and the X-ray beam diameter is 100 μmφ and scans a range of 1400 μm linearly. X-ray photoelectron spectroscopy is a technique 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 several nm or less 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 the catalyst) 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 or more, more preferably 0.5 g / cm 3 or more, and even more preferably 1 g / cm 3 or more. On the other hand, from the viewpoint of improving the selectivity of the target product, the upper limit is preferably 50 g / cm 3 or less, more preferably 30 g / cm 3 or less, and even more preferably 20 g / cm 3 or less.

[0022] [Method for producing the catalyst] Another embodiment of the present invention is a method for producing a catalyst, which is a method for producing a catalyst containing at least molybdenum and bismuth, and includes the following steps (i) to (v). The obtained catalyst preferably has B / A as described above of 1.3 to 5. (i) A step of mixing at least a molybdenum raw material and a bismuth raw material with a solvent to obtain a slurry (solution A). (ii) A liquid is stirred at a temperature 1 to 30 °C lower than the boiling point of the solvent for 20 to 90 minutes to obtain a slurry (B liquid). (iii) The B liquid 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 (C liquid). (iv) The C liquid is dried to obtain a dried product. (v) The dried product is calcined to obtain a catalyst. The method for producing a catalyst according to the present invention may further have a shaping step described later. Hereinafter, each step will be described in detail.

[0023] (Step (i)) In step (i), at least a molybdenum raw material and a bismuth raw material are mixed with a solvent to obtain a slurry (A liquid). The A liquid is prepared by mixing the raw materials of molybdenum and bismuth with the solvent. Further, the raw materials of each element contained in the formula (1) (hereinafter also referred to as catalyst raw materials) may be further mixed. The usage amount of the catalyst raw materials may be appropriately adjusted so as to obtain a desired catalyst composition. The catalyst raw materials are not particularly limited, and nitrates, carbonates, hydrogen carbonates, acetates, ammonium salts, sulfates, oxides, chlorides, hydroxides, halides, oxo acids, oxo acid salts, etc. of each element can be used alone or in combination of two or more.

[0024] Examples of the molybdenum raw material include ammonium paramolybdate, molybdenum trioxide, molybdic acid, molybdenum chloride, etc., and it is preferable to use ammonium paramolybdate. Examples of the bismuth raw material include bismuth nitrate, bismuth oxide, basic bismuth carbonate, etc., and it is preferable to use bismuth oxide. Examples of the iron raw material include iron nitrate, iron hydroxide, iron trioxide, etc., and it is preferable to use iron nitrate.

[0025] The solvent is not particularly limited as long as it can dissolve or disperse the catalyst raw materials, but it preferably contains at least water, more preferably 50% by mass or more of the total solvent is water, still more preferably 80% by mass or more of the total solvent is water, and water alone may be used. The solvent may also contain an organic solvent. The organic solvent is not particularly limited, and examples thereof include alcohol and acetone. The amount of the solvent used is not particularly limited, but it is preferably 30 to 400 parts by mass with respect to 100 parts by mass in total of the 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 (solution A1) containing molybdenum, bismuth, and the X and Y elements in the formula (1), and a solution or slurry (solution A2) containing iron and the M element in the formula (1). (ii-2) A step of mixing the solution A1 and the solution A2 to prepare a solution A. Hereinafter, each step will be described in detail.

[0028] <Step (i-1)> In step (i-1), a solution or slurry (solution A1) containing molybdenum, bismuth, and the X and Y elements in the formula (1), and a solution or slurry (solution A2) containing iron and the M element of the formula (1) are prepared. The order of preparing the solution A1 and the solution A2 is not limited, and the solution A1 and the solution A2 may be prepared simultaneously. The usage amount of each catalyst raw material is preferably adjusted so that the obtained catalyst has the composition represented by the formula (1). The amount of the solvent used is not particularly limited, but for the solution A1, it is preferably 70 to 400 parts by mass with respect to 100 parts by mass in total of the catalyst raw materials. For the solution A2, it is preferably 30 to 230 parts by mass with respect to 100 parts by mass in total of the catalyst raw materials.

[0029] <Step (i-2)> In step (i-2), the A1 solution and the A2 solution obtained in the above step (i-1) are mixed to prepare an A solution.

[0030] (Step (ii)) In step (ii), the A solution obtained in the above step (i) is stirred at a temperature 1 to 30 °C lower than the boiling point of the solvent for 20 to 90 minutes to obtain a slurry (B solution). For example, when water is used as the solvent in step (i), since the boiling point of water is 100 °C, in step (ii), the A solution is stirred at 70 to 99 °C. When a plurality of solvents having 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 having the largest mass ratio. In step (ii), when dissolving the catalyst raw material in the solvent, the temperature and stirring time are set as described above to keep the solubility of the bismuth raw material constant. As a result, when a bismuth molybdate composite oxide layer is formed in step (iii) described later, it is considered that bismuth serving as an active site is preferably deposited 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 decreases, and the B / A of the obtained catalyst tends to be 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 increases, and the B / A of the obtained catalyst tends to be greater than 5.

[0031] The upper limit of the temperature when stirring the A solution 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 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, more preferably 40 minutes or more. The upper limit is preferably 80 minutes or less, more preferably 70 minutes or less.

[0033] (Step (iii)) In step (iii), the liquid B obtained in step (ii) is stirred at a temperature 2°C or more higher than the temperature of step (ii) for 10 minutes to 10 hours to obtain a slurry (liquid C). In step (iii), a bismuth molybdate composite oxide layer is formed. At this time, by stirring the liquid B in which the solubility of bismuth was adjusted in step (ii) at the above temperature for the above time, when forming the bismuth molybdate composite oxide layer, bismuth serving as an active site is preferably deposited on the surface, and it is considered that a catalyst with B / A of 1.5 to 5 can be obtained. When the temperature in step (iii) is lower than the specified value or the stirring time is shorter than the specified value, the deposition of bismuth on the surface is not promoted, and the B / A of the obtained catalyst tends to be 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 deposition of bismuth on the surface becomes excessive, and the B / A of the obtained catalyst tends to be greater than 5.

[0034] The lower limit of the temperature when stirring the liquid B is preferably 3°C or more higher than the temperature of step (ii) more preferably 5°C or more higher, even more preferably 6°C or more higher, and particularly preferably 8°C or more higher. The upper limit is preferably 20°C or less higher than the temperature of step (ii), and more preferably 10°C or less higher. Also, the temperature when stirring the liquid B is preferably a temperature 1 to 20°C higher than the boiling point of the solvent. For example, when water is used as the solvent in step (i) above, since the boiling point of water is 100°C, in step (iii), it is preferable to stir the liquid B at 101 to 120°C. The lower limit of the temperature when stirring the liquid B 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 the above step (iii) is dried to obtain a dried product. For the drying of liquid C, known methods such as drum drying method, airflow drying method, evaporation to dryness method, spray drying method, etc. can be used. The drying temperature is preferably 120 to 500 °C, more preferably the lower limit is 140 °C or higher and the upper limit is 350 °C or lower. The drying is preferably carried out so that the moisture content of the obtained dried product is 0.1 to 4.5% by mass. These conditions can be appropriately selected according to the desired shape and size of the catalyst. By carrying out the drying of liquid C, the adhesion of the dried product can be suppressed and the yield can be improved.

[0037] (Step (v)) In step (v), the dried product obtained in the above step (iv) is calcined to obtain a catalyst. The calcination can also be carried out after performing the shaping step described later to obtain a shaped product, but from the viewpoint of catalyst strength, it is preferable to carry out the calcination before the shaping step. In the present invention, after these calcinations, including those after shaping, they are collectively referred to as catalysts. The calcination may be carried out only once, or may be carried out in a plurality of times in combination with the shaping step described later. For example, first, primary calcination may be carried out, the shaping step described later may be performed on the obtained primary calcined product, and secondary calcination may be carried out on the obtained shaped product. Also, primary calcination and secondary calcination may be carried out, and the shaping step may be performed on the obtained catalyst. The calcination is preferably carried out under the flow of an oxygen-containing gas such as air or under the flow of an inert gas. "Inert gas" refers to a gas that does not reduce the catalytic activity, and examples include nitrogen, carbon dioxide gas, helium, argon, etc.

[0038] 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. The calcination time is preferably 0.5 to 40 hours, and the lower limit is more preferably 1 hour or longer. The calcination time means the time during which the temperature is maintained after reaching a predetermined calcination temperature.

[0039] Among these, it is preferable to perform primary firing on the dried product and then perform shaping, and then perform secondary firing on the obtained shaped product. In this case, the firing temperature of the primary firing is preferably 200 to 600 °C, more preferably the lower limit is 250 °C or higher and the upper limit is 450 °C or lower. The firing time of the primary firing 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 during the primary firing are not particularly limited. For example, a box-type firing furnace, a tunnel furnace-type firing furnace, etc. may be used to fire the dried product or the shaped product in a fixed state. Also, a rotary kiln or the like may be used to fire the dried product or the shaped product while it is being fluidized.

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

[0041] (Shaping step) In the shaping step, the dried product obtained in the above step (iv) or the fired product obtained in the above step (v) is shaped to obtain a shaped product. The shaping method is not particularly limited, and known dry or wet shaping methods can be applied. For example, tableting, extrusion, compression molding, rolling granulation, etc. may be mentioned. During shaping, conventionally known additives, for example, organic compounds such as polyvinyl alcohol and carboxymethyl cellulose may be added. Further, inorganic compounds such as graphite and diatomaceous earth, and inorganic fibers such as glass fiber, ceramic fiber, and carbon fiber may be added.

[0042] The shape of the formed product is not particularly limited, and examples include any shape such as spherical, cylindrical, ring-shaped, star-shaped, and granular after pulverization and classification after forming. Among these, from the perspective of mechanical strength, spherical, cylindrical, and ring-shaped are preferred. The size of the formed 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 diameter of the sphere is more preferably 0.5 mm or more, even more preferably 1 mm or more, and particularly preferably 3 mm or more. Also, the upper limit of the diameter of the sphere is more preferably 8 mm or less, even more preferably 6 mm or less. In the case of a ring shape or a columnar shape, it is preferable that both the diameter of the circle at the bottom surface of the ring or the column and the height are 0.1 to 10 mm. The lower limit of the diameter and the height is more preferably 0.5 mm or more, even more preferably 1 mm or more, and particularly preferably 3 mm or more. Also, the upper limit of the diameter and the height is more preferably 8 mm or less, even more preferably 6 mm or less. In the case of other shapes, the length between the two farthest points in the catalyst body 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. Also, the upper limit of the length between the two points is more preferably 8 mm or less, even more preferably 6 mm or less. Thereby, the selectivity of the target product and the catalyst life are improved.

[0043] The outer surface area of the formed product is not particularly limited, but from the perspective of stably producing the target product over a long period, the lower limit is 0.01 cm 2 or more, preferably 0.05 cm 2 or more, more preferably 0.1 cm 2 or more. On the other hand, from the perspective of improving the selectivity of the target product, the upper limit is 4 cm 2 or less, preferably 3 cm 2 or less, more preferably 2 cm 2 or less.

[0044] The volume of the formed product is not particularly limited, but from the perspective of stably producing the target product over a long period, the lower limit is 0.0002 cm 3 or more, preferably 0.002 cm 3 or more, more preferably 0.02 cm 3The above is 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, and 1 cm 3 is more preferable, and 0.5 cm 3 is even more preferable.

[0045] The mass of the molded product is not particularly limited. However, from the viewpoint of stably producing the target product over a long period, 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. However, from the viewpoint of stably producing the target product over a long period the lower limit is preferably 0.2 g / cm 3 or more, more preferably 0.3 g / cm 3 or more, and even more preferably 0.4 g / cm 3 or more. On the other hand, from the viewpoint of improving the selectivity of the target product, the upper limit is preferably 1 g / cm 3 or less, more preferably 0.9 g / cm 3 or less, and even more preferably 0.8 g / cm 3 or less. The bulk density of the molded product means a value calculated from the total mass of the molded product when the molded product is filled in a 100 ml graduated cylinder by a method conforming to JIS-K 7365.

[0047] The obtained molded product may be supported on a carrier. Examples of the carrier used for the support include silica, alumina, silica-alumina, magnesia, titania, silicon carbide, etc. Further, the molded product can also be diluted with an inert substance such as silica, alumina, silica-alumina, magnesia, titania, silicon carbide, etc. and used. As described above, the catalyst can be produced.

[0048] [Process for producing α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid] In the process for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid according to the present invention, the corresponding α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid is produced from an alkene, an alcohol or an ether using the catalyst according to the present invention or the catalyst produced by the production method according to the present invention.

[0049] Examples of the alkene include propylene and isobutylene. Examples of the alcohol include t-butyl alcohol and isobutyl alcohol. Examples of the ether 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, when 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. Also, when 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 the selectivity of the target product, the α,β-unsaturated aldehyde and the α,β-unsaturated carboxylic acid are preferably methacrolein and methacrylic acid, respectively.

[0050] The process for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid according to the present invention can be carried out by bringing the catalyst according to the present invention or the catalyst produced by 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] Although the reactor is not particularly limited, it is preferable to use a tubular reactor equipped with reaction tubes filled with a catalyst. Industrially, it is more preferable to use a multitubular reactor equipped with a plurality of such reaction tubes. The catalyst layer in the reactor may be a single layer, or a plurality of catalysts with different activities may be filled separately in a plurality of layers. Further, the catalyst may be diluted with an inert carrier for activity control and then filled.

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

[0053] The concentration of oxygen in the raw material gas is preferably 0.1 to 5 moles per mole of the raw material organic compound, more preferably 0.5 mole or more as the lower limit and 3 moles or less as the upper limit. From the viewpoint of economy, it is preferable to use air as the oxygen source of the raw material gas. Further, if necessary, a gas enriched with oxygen by mixing pure oxygen with air or the like may be used. From the viewpoint of economy, the raw material gas may be diluted with an inert gas such as nitrogen or carbon dioxide gas. Furthermore, steam may be added to the raw material gas. By carrying out the reaction in the presence of steam, α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid can be obtained with a higher selectivity. The concentration of steam in the raw material gas is preferably 0.1 to 50% by volume, more preferably 1% by volume or more as the lower limit and 40% by volume or less as the upper limit.

[0054] The reaction pressure is preferably 0 to 1 MPa(G). Here, "(G)" is the gauge pressure, and 0 MPa(G) means that the reaction pressure is atmospheric pressure. The reaction temperature is preferably 200 to 450 °C, more preferably 250 °C or more as the lower limit and 400 °C or less as the upper limit. 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 as described above, α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid corresponding to the raw material organic compound used can be obtained with high selectivity.

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

[0057] Examples of the α,β-unsaturated aldehyde include (meth)acrolein, crotonaldehyde (β-methylacrolein), cinnamaldehyde (β-phenylacrolein), and the like. The α,β-unsaturated carboxylic acid to be 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 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. Note that “(meth)acrolein” indicates acrolein and methacrolein, and “(meth)acrylic acid” indicates acrylic acid and methacrylic acid.

[0058] The method for producing α,β-unsaturated carboxylic acid according to the present invention can be carried out by bringing the catalyst according to the present invention or the catalyst produced by the production method according to the present invention into contact with a raw material gas containing α,β-unsaturated aldehyde and oxygen in a reactor. As the catalyst, it is preferable to use a heteropolyacid catalyst or the like. As the reactor, the same reactor as in the above-described method for producing α,β-unsaturated aldehyde and / or α,β-unsaturated carboxylic acid can be used. The catalyst layer in the reactor may be a single layer, or a plurality of catalysts having different activities may be filled in a plurality of layers respectively. Further, the catalyst may be diluted and filled with an inert carrier in order to control the activity.

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

[0060] The concentration of oxygen in the raw material gas is preferably 0.4 to 4 moles per mole of α,β-unsaturated aldehyde, more preferably not less than 0.5 mole and not more than 3 moles. From the perspective of economy, it is preferable to use air as the oxygen source of the raw material gas. Additionally, if necessary, a gas in which pure oxygen is mixed with air or the like to enrich oxygen may also be used.

[0061] From the perspective of economy, the raw material gas may be diluted with an inert gas such as nitrogen or carbon dioxide gas. Furthermore, water vapor may be added to the raw material gas. By conducting the reaction in the presence of water vapor, α,β-unsaturated carboxylic acid can be obtained with a higher selectivity. The concentration of water vapor in the raw material gas is preferably 0.1 to 50% by volume, more preferably not less than 1% by volume and not more than 40% by volume.

[0062] The reaction pressure is preferably 0 to 1 MPa(G). The reaction temperature is preferably 200 to 450 °C, more preferably not less than 250 °C and not more than 400 °C. 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 not less than 1 second, while the upper limit is more preferably not more than 10 seconds, and even more preferably not more than 5 seconds.

[0063] [Method for Producing α,β-unsaturated Carboxylic Acid Ester] In the method for producing an α,β-unsaturated carboxylic acid ester 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 examples thereof include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, and the like. Examples of the obtained α,β-unsaturated carboxylic acid ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, and the like. 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] 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 the Examples and Comparative Examples, "parts" means parts by mass.

[0065] (Composition of the catalyst) The composition of the whole catalyst was determined by analyzing the components obtained by dissolving the catalyst in aqueous ammonia by ICP emission spectrometry. As the analyzer, ICP Optima 8300 (manufactured by Perkin Elmer) was used, with output: 1300 W, plasma gas flow rate: 10 L / min, auxiliary gas flow rate: 0.2 L / min, nebulizer gas flow rate: 0.55 L / min, and detector: segmented array type CCD. Further, 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 whole obtained catalyst.

[0066] (X-ray photoelectron spectroscopy of the catalyst) The value of B was 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. As the analyzer, QuanteraII (manufactured by ULVAC-PHI, Inc.) was used, with X-ray: HP mode - monochromatic Al source, output: 300 W, capture angle: 45°, and the X-ray beam diameter of 100 μmφ scanning linearly over a range of 1400 μm.

[0067] (Reaction 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 the oxidation of isobutylene as an example. The analysis of the raw material gas and products in the reaction evaluation was performed using the following gas chromatography. Analysis of methacrolein: GC-2014 manufactured by Shimadzu Corporation, column: QUADREX 007-CW 20 m × 0.32 mm, film thickness: 3 μm Analysis of methacrylic acid: GC-2014 manufactured by Shimadzu Corporation, column: DB-FFA manufactured by J&W P, 30 m × 0.32 mm, film thickness 1.00 μm From the results of gas chromatography, the total selectivity of the produced methacrolein and methacrylic acid was determined by the following formula. Total selectivity of methacrolein and methacrylic acid (%) = (P1 + P2) / M1 × 100 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.

[0068] <Example 1> Using 2,000 parts by mass of pure water at 60 °C as a solvent, 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 were mixed to obtain Solution A1. Separately from Solution 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 1,000 parts by mass of pure water to obtain Solution A2. Then, Solution A1 and Solution A2 were mixed to obtain Solution A.

[0069] The obtained Solution A was heated to 95°C and stirred for 1 hour while maintaining the liquid temperature at 95°C to obtain Solution B. The obtained Solution B was heated to 103°C and stirred for 3 hours while maintaining the liquid temperature at 103°C to obtain Solution C. The obtained Solution C was dried in a spray dryer to obtain a dried product. The dried product was in a good drying state without adhesion to the inner wall surface of the spray dryer. The obtained dried product was first calcined at 300°C for 1 hour in an air atmosphere and then pulverized. Next, the pulverized dried product after calcination was pressure-molded and then crushed to obtain crushed particles. Then, the crushed particles were classified, and the pulverized particles that passed through a sieve with an aperture of 2.36 mm and did not pass through a sieve with an aperture of 0.71 mm were collected. Next, the collected crushed particles were secondarily calcined at 500°C for 3 hours in an air atmosphere to obtain a catalyst. The composition of the obtained catalyst excluding oxygen was Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 Sb 0.6 Cs 0.6 It was as follows. Further, ICP emission analysis 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 filled 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: 5% by volume of isobutylene, 12% by volume of oxygen, 10% by volume of steam, and 73% by volume of nitrogen Reaction temperature: 340°C Contact time between the raw material gas and the catalyst: 2.7 seconds

[0071] <Example 2> Solution A1 was prepared in the same manner as in Example 1 except that 24.8 parts by mass of antimony trioxide was used. 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 stirred for 1 hour while maintaining the liquid temperature at 95°C to obtain Solution B. The obtained Liquid B was heated to 103°C, and while maintaining the liquid temperature at 103°C, it was stirred for 5 hours to obtain Liquid 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 without adhering to the inner wall surface of the spray dryer. The obtained dried product was subjected to primary firing, shaping, and secondary firing in the same manner as in Example 1 to obtain a catalyst The composition of the obtained catalyst excluding oxygen was Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 Sb 0.72 Cs 0.6 It was as follows. In addition, ICP emission analysis and X-ray photoelectron spectroscopy analysis were performed on the catalyst. The calculated values of A, B, and B / A are shown in Table 1. Next, reaction evaluation was carried out in the same manner as in Example 1 using the obtained catalyst. The results are shown in Table 1.

[0072] <Example 3> A1 liquid was prepared in the same manner as in Example 1 except that 15.5 parts by mass of antimony trioxide was used. Separately from the A1 liquid, A2 liquid was prepared in the same manner as in Example 1. Next, the A2 liquid was mixed with the A1 liquid to obtain Liquid A. The obtained liquid was heated to 95°C, and while maintaining the liquid temperature at 95°C, it was stirred for 1 hour to obtain Liquid B. The obtained Liquid B was heated to 103°C, and while maintaining the liquid temperature at 103°C, it was stirred for 7 hours to obtain Liquid 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 without adhering to the inner wall surface of the spray dryer. The obtained dried product was subjected to primary firing, shaping, and secondary firing in the same manner as in Example 1 to obtain a catalyst. The composition of the obtained catalyst excluding oxygen was Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 Sb 0.45 Cs 0.6 ​It was. Further, 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, reaction evaluation was carried out in the same manner as in Example 1 using the obtained catalyst. The results are shown in Table 1.

[0073] <Comparative Example 1> A B solution was obtained in the same manner as in Example 1. The obtained B solution was dried using a spray dryer to obtain a dried product. That is, step (iii) was not carried out, and the dried product was obtained by drying the B solution. The dried product was in a good drying state without adhering to the inner wall surface of the spray dryer. The obtained dried product was subjected to primary firing, shaping, and secondary firing in the same manner as in Example 1 to obtain a catalyst. The composition of the obtained catalyst excluding oxygen was Mo 12 Bi 0.7 Fe 2.1 Co 7.5 W 0.2 Sb 0.6 Cs 0.6 It was. Further, 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, reaction evaluation was carried out in the same manner as in Example 1 using the obtained catalyst. The results are shown in Table 1.

[0074] <Comparative Example 2> An A solution was obtained in the same manner as in Example 1. The obtained A solution was heated to 95 °C and stirred for 2 hours while maintaining the liquid temperature at 95 °C. That is, in step (ii), stirring was carried out for a longer time than 90 minutes to obtain a B' solution. The obtained B' solution was heated to 100 °C and stirred for 1 hour while maintaining the liquid temperature at 100 °C to obtain a C solution. The obtained C solution was dried using a spray dryer to obtain a dried product. The dried product was in a good drying state without adhering to the inner wall surface of the spray dryer. The obtained dried product was subjected to primary firing, shaping, and secondary firing in the same manner as in Example 1 to obtain a catalyst. The composition of the obtained catalyst excluding oxygen was Mo 12 Bi0.7 Fe 2.1 Co 7.5 W 0.2 Sb 0.6 Cs 0.6 It was. Further, ICP emission analysis 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, reaction evaluation was carried out in the same manner as in Example 1 using the obtained catalyst. The results are shown in Table 1.

[0075]

Table 1

[0076] As shown in Table 1, in Examples 1 to 3 using a catalyst in which B / A was within the specified range, the total selectivity of methacrolein and methacrylic acid was good. In addition, methacrylic acid can be obtained by oxidizing the methacrolein obtained in this example, and a methacrylic acid ester can be obtained by esterifying methacrylic acid.

Industrial Applicability

[0077] According to the present invention, it is possible to provide a catalyst capable of producing a target product such as an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid with high selectivity, which is industrially useful.

Claims

1. A catalyst used in producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid from an alkene, an alcohol or an ether, comprising at least molybdenum, bismuth and iron, a ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP (inductively coupled plasma) emission spectroscopy is A, and a ratio of a peak area of ​​bismuth atoms to a peak area of ​​molybdenum atoms measured by X-ray photoelectron spectroscopy is B, B / A is 1.5 to 4; A catalyst, wherein the value of A is 0.02 to 0.

1.

2. A catalyst used in producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid from an alkene, an alcohol or an ether, comprising at least molybdenum, bismuth and iron, a ratio of the amount of bismuth atoms to the amount of molybdenum atoms calculated by ICP (inductively coupled plasma) emission spectroscopy is A, and a ratio of a peak area of ​​bismuth atoms to a peak area of ​​molybdenum atoms measured by X-ray photoelectron spectroscopy is B, B / A is 1.5 to 4; A catalyst, wherein the value of B is 0.04 to 0.

2.

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

4. The catalyst according to claim 1 or 2, wherein the value of B is from 0.07 to 0.

16.

5. The catalyst according to claim 1 or 2, wherein the catalyst 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 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 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 atomic ratios of each element, and when 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, and g=0 to 20, and h represents the atomic ratio of each element. The oxygen atom ratio is required to satisfy the atomic valence of each component.)

6. Density is 0.2 g / cm ３ Above, 50g / cm ３ 3. The catalyst according to claim 1 or 2, wherein:

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

8. External surface area is 0.01cm ２ More than 4cm ２ 8. The molded article according to claim 7, wherein:

9. Packing bulk density is 0.2 g / cm ３ Above, 1g / cm ３ 8. The molded article according to claim 7, wherein:

10. A method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid from an alkene, an alcohol or an ether by using the catalyst according to any one of claims 1 to 6.

11. A method for producing an α,β-unsaturated aldehyde and / or an α,β-unsaturated carboxylic acid from an alkene, an alcohol, or an ether, using the shaped product according to any one of claims 7 to 9.

12. 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 10 or 11.

13. 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 production method according to any one of claims 10 to 12.

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