JP3999972B2 - Method for producing acrylic acid or methacrylic acid - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
This invention uses a multi-focus oxide catalyst, a method for producing the A acrylic acid or methacrylic acid acrolein or methacrolein by gas-phase catalytic oxidation with molecular oxygen.
[0002]
[Prior art]
Catalysts used in the process of producing unsaturated acids by vapor-phase catalytic oxidation of unsaturated aldehydes are extremely important in the chemical industry and have been extensively studied. For example, a multicomponent composite oxide catalyst containing molybdenum and vanadium as basic components and further containing a modifying component is disclosed in the patent publication.
[0003]
Techniques relating to a catalyst for producing acrylic acid by vapor-phase catalytic oxidation of acrolein are described in Japanese Patent Publication No. 41-1775, Japanese Patent Publication No. 44-12129, Japanese Patent Publication No. 44-26287, Japanese Patent Publication No. 44-12886, It is described in JP-B-49-11371, JP-B-55-7414, JP-B-56-97 and the like.
[0004]
In such a production technique of acrylic acid, in the step of performing a gas phase catalytic oxidation reaction in the presence of molecular oxygen, an undesirable sequential reaction in which a part of the target product is further oxidized to become a low added value product. Is often accompanied.
[0005]
In order to suppress this sequential reaction as much as possible, it is effective to improve the effectiveness factor of the catalyst, which is the same as reducing the diffusion resistance control of the reactant as much as possible.
[0006]
Regarding catalyst effectiveness factor, it is well known that catalyst shape and pore distribution are the most dominant factors. For example, “Chemical Engineering” Vol. 30, No. 2, paragraphs 73-79 (1966) (Science and Technology Association) discusses the relationship between catalyst shape and effectiveness factor, and “Chemical Engineering IV” (Shigefumi Fujita, Hiraichiro Hirahata, edited by Tokyo Chemical Dojinsha, 1963), paragraphs 32-37 contain pores. The relationship between distribution and effectiveness factor is discussed.
[0007]
In addition, Japanese Patent Publication No. 6-9658 and Japanese Patent Publication No. 6-38918 related to the earlier application of the inventors of the present application use a catalyst to which a composite oxide such as antimony and nickel is added, and control the pore diameter. There is a description that a high yield catalyst can be obtained by doing so. JP-A-8-299797 discloses a coated catalyst containing molybdenum, vanadium, copper and antimony as essential components, and JP-A-3-218334 discloses a high yield and high productivity. A catalyst is disclosed.
[0008]
[Problems to be solved by the invention]
However, from the viewpoint of whether the above-mentioned conventional composite oxide catalyst can maintain a high acrylic acid yield stably for a long time, there is still room for improvement in these catalysts. Therefore, a catalyst having a higher yield is desired.
[0009]
Also, in recent years, when acrylic acid is produced by vapor-phase catalytic oxidation of acrolein, so-called high STY, which increases the productivity of acrylic acid under a high-load reaction condition that increases the supply amount of acrolein per unit volume of the catalyst. (Space-Time Yield) Reaction conditions are required, but the oxidation reaction of acrolein is an exothermic reaction, and if the supply amount of acrolein as a raw material is increased, a uniform reaction in the entire catalyst layer is difficult to occur. This causes a locally high temperature heat generation region, a so-called hot spot.
[0010]
Although it is difficult to actually confirm fine hot spots on the catalyst in the manufacturing process, it is assumed that this is one of the factors that reduce the catalyst performance and the catalyst life. Therefore, the reaction results (acrolein conversion rate and acrylic acid yield) decreased with the passage of the reaction time, and the stability over time was insufficient.
[0011]
An object of the invention according to each claim of the present application is to solve the above-described problems and to stably use an oxidation catalyst used in a step of producing acrylic acid by a gas-phase catalytic oxidation reaction of acrolein with a high yield for a long time. It is to be able to produce an acid.
[0012]
That is, the reaction results (acrolein conversion rate and acrylic acid yield) can be achieved by using a composite oxide catalyst that can efficiently perform the gas-phase catalytic oxidation reaction of acrolein even at relatively low temperature conditions and suppressing the occurrence of hot spots. Is to produce a composite oxide catalyst that does not easily decrease over time.
[0013]
[Means for Solving the Problems]
The inventors of the present application have conducted extensive studies on a composite oxide catalyst containing molybdenum, niobium, and the like. As a result, a catalyst produced using a specific raw material has high activity in the acrolein oxidation reaction, and the yield of acrylic acid is high. The present invention has been completed by finding that the rate is high.
[0014]
That is, the invention of the present application, carbonizing the composite oxide catalyst represented by the following formula (1) in the manufacture by integration and heat treatment element source, as a source of Si and C in the composite oxide catalyst with a compound of silicon, that using niobium oxalate ammonium compound to produce a composite oxide catalyst as a source of Nb, using the composite oxide catalyst, gas-phase catalytic oxidation of acrolein or methacrolein with molecular oxygen It was set as the manufacturing method of acrylic acid or methacrylic acid which consists of .
(Mo) ₁₂ (X) _a (Y) _b (Z) _c (Si) _d (C) _e (O) _f (1)
(In the formula, Mo, Nb, V, Cu, W, Sb, Fe, Si, C and O are element symbols, X represents (Nb) or (Nb and V), and Y represents Cu and W. Represents at least one element selected, Z represents at least one element selected from Sb and Fe, a, b, c, d, e, and f represent the atomic ratio of each element; A is 0 <a ≦ 12, b is 0 <b ≦ 10, c is 0 <c ≦ 8, d is 0 <d ≦ 1000, e is 0 <e ≦ 1000, and f is d among the above components. (The number is determined by the degree of oxidation of each component element excluding e.)
[0015]
In the method for producing a composite oxide catalyst by integrating element supply sources and heat treatment as described above, a silicon carbide compound is used as a supply source of Si and C in the composite oxide catalyst, and oxalic acid is used as a supply source of Nb. By using the niobium ammonium compound, the activity in the integration of the element source and the heat treatment, that is, the acrolein conversion amount per unit amount of the catalyst is improved, the acrylic acid selectivity of the catalyst is further improved, even under relatively low temperature conditions. A composite oxide catalyst capable of efficiently performing a gas phase catalytic oxidation reaction of acrolein can be produced.
[0016]
Acrylic acid or methacrylic acid, which is a processing step in which the integration of the source of the required elements and the heat treatment in the production process of such an excellent composite oxide catalyst include the following steps (a) to (d) in sequence. An acid production method is preferred.
(A) Step of (b) preparing a precursor of a catalyst component by mixing an aqueous solution containing a catalyst component element or an aqueous dispersion of a compound containing these elements of the catalyst component obtained in step (a) Step (c) of heat-treating the precursor The step (c) of forming the heat-treated powder obtained in step (b) with a binder, if necessary. The molded catalyst obtained in step (c) is in an inert gas or controlled. Step of calcining in an oxygen concentration atmosphere Furthermore, it is preferable to use one or more binders selected from the group consisting of silica, graphite and crystalline cellulose as the binder in step (c). The composite oxide catalyst is preferably used for producing acrylic acid or methacrylic acid by vapor-phase catalytic oxidation of acrolein or methacrolein with molecular oxygen.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The catalyst used in the present invention is an oxide or composite oxide having a metal element composition represented by the above formula (1). X in the formula is (Nb) or (Nb and V), Y is at least one element selected from Cu and W, and Z is at least one element selected from Sb and Fe.
[0018]
As described above, the composition ratio of each element is as follows: a is 0 <a ≦ 12, b is 0 <b ≦ 10, c is 0 <c ≦ 8, d is 0 <d ≦ 1000, e Is a number determined by the degree of oxidation of each component element excluding d and e among the above components, more preferably, a is 1 ≦ a ≦ 6 and b is 0.5. ≦ b ≦ 4, c is 0.5 ≦ c ≦ 5, d is 5 ≦ d ≦ 500, and e is 5 ≦ e ≦ 500.
[0019]
The composite oxide catalyst of the present invention is prepared by preparing an aqueous solution (or aqueous dispersion) containing each metal element constituting the catalyst component represented by the formula (1) or a compound thereof, and drying it to obtain a powder. It can be obtained by heat-molding it and then firing it.
[0020]
The integration referred to in the present invention is preferably such that each element is integrally contained by mixing a source compound containing each component element in an aqueous system consisting of an aqueous solution or a water dispersion, and aging treatment as necessary. Say that.
[0021]
(B) a method of mixing each of the above-mentioned source compounds at once, (b) a method of mixing each of the above-mentioned source compounds at once, and further aging treatment, (c) each of the above-mentioned source compounds (D) a method in which each of the above-mentioned source compounds is repeatedly mixed and aged, and a method in which (a) to (d) are combined, Included in the concept of integration of the source compound in an aqueous system.
[0022]
Here, as described in the Chemical Dictionary (Kyoritsu Shuppan), the above-mentioned “aging” means that “industrial raw materials or semi-finished products are processed and processed under specific conditions such as constant temperature for a certain period of time. This refers to an operation for obtaining, raising, or progressing a predetermined reaction of physical and chemical properties. In addition, said fixed time says the range of 1 minute-24 hours in this invention, and said fixed temperature is the range of room temperature-200 degreeC.
[0023]
In the integration described above, not only the source compound of each element but also support materials such as alumina, silica, and refractory oxide are included as targets for such integration.
[0024]
The compound of the catalyst constituent element used as the production raw material may be a compound that becomes an oxide by firing. Examples of the raw material of the catalyst constituent element compound include metal antimony, antimony compound, molybdenum compound, niobium compound, vanadium compound, copper compound, tungsten compound, and iron compound. Specific examples of compounds include halides, sulfates, nitrates, ammonium salts, oxides, carboxylates, ammonium carboxylates, ammonium halides, hydrogen acids, acetylacetonates, alkoxides and the like of catalytically active elements. Take as an example. A specific example of the niobium compound that can be used in the present invention is niobium ammonium oxalate, and examples of the silica supply source include colloidal silica, powdered or granular silica, and the like. Moreover, alumina etc. are mentioned as an aluminum supply source, The compound of these catalyst constituent elements may be used independently, and 2 or more types may be mixed and used for them.
[0025]
The manufacturing process will be described in order. First, an aqueous solution or an aqueous dispersion of the above-described catalyst constituent elements, components or their compounds is prepared. Hereinafter, unless otherwise specified, these aqueous solutions or aqueous dispersions are referred to as slurry solutions.
[0026]
The slurry solution can be obtained by uniformly mixing each constituent compound and water. In the present invention, the slurry solution is preferably an aqueous solution. The use ratio of the compound of each constituent component in the slurry solution may be such that the atomic ratio of each catalyst constituent element is in the above range.
[0027]
The amount of water used is not particularly limited as long as the total amount of the compound can be completely dissolved or uniformly mixed, but may be appropriately determined in consideration of the following heat treatment method and temperature. Usually, it is 100-2000 weight part with respect to 100 weight part of total weight of a compound. If the amount of water is less than the above predetermined amount, the compound may not be completely dissolved or may not be uniformly mixed. Moreover, if the amount of water exceeds the predetermined amount, a problem arises that the energy cost during heat treatment is increased.
[0028]
Next, it is preferable to dry the slurry solution obtained in the above step. The drying method is not particularly limited as long as the slurry solution can be completely dried and a powder can be obtained. For example, drum drying, freeze drying, spray drying and the like are preferable methods.
[0029]
Spray drying is a method that can be preferably applied to the present invention because it can be dried from a slurry solution state to a homogeneous powder state in a short time.
[0030]
The drying temperature varies depending on the concentration of the slurry solution, the feeding speed, etc., but 90 to 150 ° C. is appropriate at the outlet temperature of the dryer. Moreover, it is preferable to dry so that the particle size of dry powder may be 10-200 micrometers.
[0031]
Next, the precursor containing the catalyst component obtained as described above is heat-treated by a known method. The temperature of the heat treatment is usually 160 to 450 ° C., preferably 200 to 350 ° C. The heat treatment time is usually 1 to 20 hours, more preferably 2 to 10 hours. The powder obtained through such a heat treatment step becomes a catalyst having a uniform particle size and quality and less pulverization.
[0032]
The catalyst obtained by the production method of the present invention can also be obtained by molding the powder after the heat treatment. There is no particular limitation on the molding method, and heat-treated powder mixed with a binder is mixed with a molding aid such as (A) tableting molding, (B) silica gel, diatomaceous earth, alumina powder, if necessary, and extruded into a spherical or ring shape. (C) An appropriate method such as coating support molding on a spherical carrier can be adopted.
[0033]
When tableting the heat-treated powder, about 1 to 50 parts by weight of a molding aid such as a binder of silica, graphite, crystalline cellulose, etc. is used with respect to 100 parts by weight of the heat-treated powder. You can also
[0034]
Further, if necessary, inorganic fibers such as ceramic fibers and whiskers can be used as the strength improving material, thereby improving the mechanical strength of the catalyst.
[0035]
However, fibers that react with catalyst components such as potassium titanate whiskers and basic magnesium carbonate whiskers are not preferred. As the strength improving material, ceramic fiber is particularly preferable. The amount of these fibers used is usually 1 to 30 parts by weight per 100 parts by weight of the heat-treated powder. The molding aid and the strength improver are usually used by mixing with heat-treated powder.
[0036]
Thus, when the heat-treated powder is tablet-molded into a pellet shape or a ring shape, a molded product is obtained, and the molded product can be baked to obtain a target composite oxide catalyst. The firing temperature can be usually 250 to 600 ° C, preferably 300 to 500 ° C, and the firing time is 1 to 50 hours. Firing is preferably performed in an atmosphere in the presence of an inert gas or molecular oxygen.
[0037]
In addition, baking at the time of employ | adopting shaping | molding methods other than tableting shaping | molding is normally performed on the conditions for about 1 to 50 hours at 250-500 degreeC.
[0038]
The catalyst of the present invention thus obtained, particularly a tableting catalyst, is highly active when used in a gas phase catalytic oxidation reaction, and the target compound can be obtained with high selectivity. The use of the catalyst produced in the present invention is used in the step of producing an unsaturated acid using an unsaturated aldehyde as a raw material, and is preferably applied to the step of producing acrylic acid by oxidizing acrolein. That is, when the process of producing acrylics by gas phase catalytic oxidation of olefins such as propylene is divided into two processes, an unsaturated aldehyde production process by oxidation of olefins and an unsaturated carboxylic acid production process by the oxidation, and carried out. The catalyst of the present invention is useful as a catalyst used in the subsequent reaction.
[0039]
Examples and Comparative Examples
Hereinafter, the present invention will be described in detail by way of examples and comparative examples. In addition, this invention is not limited to a following example, unless the main point is exceeded.
[0040]
The acrolein conversion rate, acrylic acid selectivity, and acrylic acid yield are defined as in the following formulas (2) to (4).
(2) Acrolein conversion (mol%)
= 100 × (moles of acrolein reacted) / (moles of acrolein supplied)
(3) Acrylic acid selectivity (mol%)
= 100 x (number of moles of acrylic acid produced) / (number of moles of converted acrolein)
(4) Acrylic acid yield (mol%)
= 100 x (number of moles of acrylic acid produced) / (number of moles of acrolein supplied)
[0041]
[Example 1]
A composite metal oxide catalyst in which the empirical formula of the component elements excluding oxygen is Mo ₁₂ Nb ₁ V _2.4 Cu ₂ Sb ₁ Si ₂₀₀ C ₂₀₀ was prepared as follows. 937 ml of pure water is heated to 80 ° C., and 203.3 g of ammonium paramolybdate, 26.9 g of ammonium metavanadate, 22.2 g of ammonium niobium oxalate, 47.9 g of copper sulfate and 17.3 g of antimony trioxide are dissolved in this order. Or mixed.
[0042]
Particle size distribution with a maximum particle size of 63 μm or less, a particle size of 3% cumulative height of 50 μm or less, a particle size of 25 ± 2.0 μm of 50% cumulative height, and a particle size of 16 μm or less of 94% cumulative height. 770 g of characteristic silicon carbide powder was added and mixed thoroughly with stirring.
[0043]
The slurry was heated to 90 ° C. and dried. The dried product was heat-treated at 200 ° C., 1.5% by weight of graphite was added and mixed, and molded with a small tableting machine. This was calcined at 380 ° C. for 3 hours in a nitrogen stream in a calcining furnace to obtain a catalyst.
[0044]
In order to evaluate the obtained catalyst, it was pulverized to 20 to 28 mesh and then sized, and 0.3 g of the catalyst was filled in a U-shaped reaction tube having an inner diameter of 4 mm. The reaction tube was set in a heated night bath, the following composition gas was introduced, and the reaction was performed with SV (space velocity; flow rate of raw material gas per unit time / apparent volume of packed catalyst) of 14900 / hr. .
[0045]
Incidentally, the night bath refers to a salt bath in which a reaction tube is put into a heat medium made of an alkali metal nitrate and reacts. This heat medium melts at 200 ° C. or higher, and can be used up to 400 ° C. This reaction bath is suitable for oxidation reactions with a large exotherm. Gas composition:
Acrolein 3.4 vol%
Oxygen 9.3 vol%
Steam 41.5 vol%
Nitrogen gas 45.8 vol%
As a result of the reaction, acrolein conversion was 99.8%, acrylic acid selectivity was 98.6%, and acrylic acid yield was 98.4% at a night bath temperature of 285 ° C.
[0046]
[Example 2]
A composite metal oxide catalyst in which the empirical formula of the catalyst component excluding oxygen was Mo ₁₂ Nb ₁ V _2.4 Cu ₂ Sb _0.7 W _0.2 Si ₁₉₀ C ₁₉₀ was prepared as follows. 1100 ml of pure water is heated to 80 ° C., 211.5 g of ammonium paramolybdate, 5.2 g of ammonium paratungstate, 28.0 g of ammonium metavanadate, 23.1 g of ammonium niobium oxalate, 49.9 g of copper sulfate and trivalent oxidation 12.6 g of antimony was dissolved or mixed with sequential stirring.
[0047]
Particle size distribution with a maximum particle size of 63 μm or less, a particle size of 3% cumulative height of 50 μm or less, a particle size of 25 ± 2.0 μm of 50% cumulative height, and a particle size of 16 μm or less of 94% cumulative height. 761 g of characteristic silicon carbide powder was added and mixed thoroughly with stirring.
[0048]
The slurry was heated to 90 ° C. and dried. The dried product was heat-treated at 200 ° C., 1.5% by weight of graphite was added and mixed, and molded with a small tableting machine. This was calcined at 380 ° C. for 3 hours in a nitrogen stream in a calcining furnace to obtain a catalyst.
[0049]
The obtained catalyst was subjected to the reaction in the same manner as in Example 1. The reaction results were as follows: acrolein conversion = 99.7%, acrylic acid selectivity = 98.4%, and acrylic acid yield = 98.1% at a reaction bath temperature of 280 ° C.
[0050]
[Example 3]
A composite metal oxide catalyst in which the empirical formula of the catalyst component excluding oxygen was Mo ₁₂ Nb _1.1 V _2.4 Cu _1.9 Sb _0.8 Fe _0.3 Si ₂₀₀ C ₂₀₀ was prepared as follows. 937 ml of pure water is heated to 80 ° C., 203.9 g of ammonium paramolybdate, 27.0 g of ammonium metavanadate, 24.5 g of niobium ammonium oxalate, 45.7 g of copper sulfate, 11.7 g of ferric nitrate and trivalent oxidation 13.9 g of antimony was dissolved or mixed with sequential stirring.
[0051]
Particle size distribution with a maximum particle size of 63 μm or less, a particle size of 3% cumulative height of 50 μm or less, a particle size of 25 ± 2.0 μm of 50% cumulative height, and a particle size of 16 μm or less of 94% cumulative height. The characteristic silicon carbide powder 772g was added and fully stirred and mixed.
[0052]
The slurry was heated to 90 ° C. and dried. The dried product was heat-treated at 240 ° C., 1.5% by weight of graphite was added and mixed, and molded with a small tableting machine. This was calcined in a nitrogen stream at 380 ° C. for 3 hours in a calcining furnace to obtain a catalyst.
[0053]
The obtained catalyst was subjected to the reaction in the same manner as in Example 1. As a result of the reaction, the reaction bath temperature was 285 ° C., the acrolein conversion rate was 99.6%, the acrylic acid selectivity was 98.6%, and the acrylic acid yield was 98.2%.
[0054]
[Comparative example]
A composite metal oxide catalyst in which the empirical formula of the catalyst component excluding oxygen is Mo ₁₂ Nb ₁ V _2.6 Cu ₂ W _0.1 Ni ₁₇ Sb ₄₀ Si ₄ was prepared as follows. 866 g of basic nickel carbonate (NiCO ₃ · 2Ni (OH) ₂ · 4H ₂ O) (however, a water content of 76% is used in this equivalent amount) is dispersed in 2300 ml of pure water, and silica (Shiono) Made by Seiko Pharmaceutical Co., Ltd .: Carplex # 67) 23 g and 568 g of antimony trioxide were added and sufficiently stirred.
[0055]
The slurry was heated to concentrate and dried. The obtained dried solid was calcined at 800 ° C. for 3 hours in a muffle furnace, and the produced solid was pulverized to obtain a powder passing through a 60 mesh sieve. (Sb—Ni—Si—O powder).
[0056]
Meanwhile, 940 ml of pure water was heated to about 80 ° C., and 2.5 g of ammonium paratungstate, 207 g of ammonium paramolybdate, 29.6 g of ammonium metavanadate, 19.3 g of niobium hydroxide and 48.7 g of copper sulfate were stirred. Then, it was added and dissolved or mixed sequentially.
[0057]
Next, the Sb—Ni—Si—O powder was gradually added to this solution while stirring, and the mixture was sufficiently stirred and mixed. The obtained slurry was heated to 80 to 100 ° C., concentrated and dried, and the dried product was heat-treated at 200 ° C. and then pulverized to obtain a powder passing through a 24 mesh sieve.
[0058]
1.5% by weight of graphite was added and mixed with this, and molded with a small tableting machine. This was calcined at 400 ° C. for 5 hours in a calcining furnace as a catalyst.
[0059]
The obtained catalyst was pulverized and sized to 20 to 28 mesh, and the reactivity was examined in the same manner as in Example 1 except that the catalyst amount was 0.450 g and SV9900 / hr.
[0060]
The results were acrolein conversion = 98.6%, acrylic acid selectivity = 97.1%, and acrylic acid yield = 95.7% at a night bath temperature of 295 ° C.
[0061]
Thus, the example using SiC as the source of silicon and carbon in the catalyst and using niobium oxalate as the source of niobium has high acrylic acid selectivity even at high conversion, and SiC and niobium oxalate. The yield was 2% or more higher than the comparative example in which ammonium was not used.
[0062]
As is clear from the above results, the composite oxide catalyst obtained by the production method of the present invention can be confirmed to be an excellent catalyst in both activity and selectivity, and compared with a comparative example assuming a conventional method. Even when the reaction temperature was lowered by 10 to 15 ° C., acrylic acid could be produced efficiently.
[0063]
【The invention's effect】
As described above, the present invention uses a silicon carbide compound as a source of Si and C and a niobium ammonium oxalate compound as a source of Nb in the method for producing a composite oxide catalyst. The conversion amount of acrolein per unit amount is improved, the acrylic acid selectivity of the catalyst is improved, and a highly active composite oxide catalyst capable of efficiently performing the gas phase catalytic oxidation reaction of acrolein even under relatively low temperature conditions can be produced.
[0064]
In addition, the composite oxide catalyst obtained by the production method of the present invention can efficiently perform the gas phase catalytic oxidation reaction of acrolein even under relatively low temperature conditions, so that it is possible to suppress the occurrence of hot spots. The reaction results (acrolein conversion rate and acrylic acid yield) are less likely to decrease over time, and there is an advantage that a composite oxide catalyst that can be used stably for a long period of time even under high-load reaction conditions can be produced.

Claims (3)

The composite oxide catalyst represented by the following formula (1) in the manufacture by integration and heat treatment element source, a compound of silicon carbide used as a source of Si and C in the composite oxide catalyst, Nb Acrylic acid or methacrylic acid comprising producing a complex oxide catalyst using a niobium ammonium oxalate compound as a supply source, and subjecting acrolein or methacrolein to gas phase catalytic oxidation with molecular oxygen using the complex oxide catalyst Manufacturing method.
(Mo) ₁₂ (X) _a (Y) _b (Z) _c (Si) _d (C) _e (O) _f (1)
(In the formula, Mo, Nb, V, Cu, W, Sb, Fe, Si, C and O are element symbols, X represents (Nb) or (Nb and V), and Y represents Cu and W. Represents at least one element selected, Z represents at least one element selected from Sb and Fe, a, b, c, d, e, and f represent the atomic ratio of each element; A is 0 <a ≦ 12, b is 0 <b ≦ 10, c is 0 <c ≦ 8, d is 0 <d ≦ 1000, e is 0 <e ≦ 1000, and f is d among the above components. (The number is determined by the degree of oxidation of each component element excluding e.) The acrylic acid or the acrylic acid according to claim 1, wherein the integration of the source of the required elements and the heat treatment in the production process of the composite oxide catalyst are treatment steps including sequentially performing the following steps (a) to (d): A method for producing methacrylic acid.
(A) Step of (b) preparing a precursor of a catalyst component by mixing an aqueous solution containing a catalyst component element or an aqueous dispersion of a compound containing these elements of the catalyst component obtained in step (a) Step (c) of heat treating the precursor The step (c) of forming the heat treated powder obtained in step (b) together with a binder, if necessary. The molded catalyst obtained in step (c) is in an inert gas or controlled. Baking process in oxygen concentration atmosphere The method for producing acrylic acid or methacrylic acid according to claim 2, wherein the binder in the production step (c) of the composite oxide catalyst is one or more binders selected from the group consisting of silica, graphite and crystalline cellulose .