JP2005169311A - Production method for complex oxide catalyst - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To produce a complex oxide catalyst for producing an unsaturated aldehyde or an unsaturated carboxylic acid from a corresponding olefin with a high yield; and a production method for the catalyst. <P>SOLUTION: The complex oxide catalyst is used for producing, from an olefin, the unsaturated aldehyde or the unsaturated carboxylic acid each corresponding to the olefin, by vapor phase catalytic oxidation with a molecular-oxygen-containing gas and at least contains (A) molybdenum, (B) bismuth, (C) cobalt and/or nickel, and (D) iron. The method for producing the catalyst comprises drying a water dispersion which contains a component (A)-containing material, a component (B)-containing material, a component (C)-containing material, and a component (D)-containing material in a unified state and has a nitrate group content satisfying the formula: 2≤NO<SB>3</SB>/(3×Fe+2×(Co+Ni)), subjecting the dried product to a pretreatment for thermally treating to give a catalyst precursor powder, unifying the precursor powder with a component (B)-containing material, and drying and sintering the resultant unified product. In the formula, NO<SB>3</SB>, Fe, Co and Ni show the molar contents of nitrate group, iron, cobalt, and nickel, respectively. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a composite oxide catalyst capable of advantageously producing a corresponding unsaturated aldehyde and unsaturated carboxylic acid with high reproducibility and high reproducibility by gas phase catalytic oxidation of olefin with molecular oxygen-containing gas.

  Conventionally, a catalyst for producing acrolein and acrylic acid by vapor-phase catalytic oxidation of propylene with molecular oxygen, and for producing methacrolein and methacrylic acid by vapor-phase catalytic oxidation of isobutylene with molecular oxygen-containing gas. Various catalysts have been proposed.

  From the viewpoint of effective utilization of raw material olefin resources and rationalization of processes in the reaction, these catalysts are required to have catalytic performances that are as high as possible in terms of olefin conversion and target product selectivity. In this case, for example, in the process of producing acrolein and acrylic acid from propylene, when the conversion rate and selectivity are improved even by 0.1%, the amount of acrolein and acrylic acid that are obtained is several hundred to Significant increase at several thousand tons / year. Therefore, improvement of catalyst performance such as raw material conversion rate and selectivity greatly contributes to effective utilization of resources and rationalization of processes even if a small value.

  Conventionally, various proposals have been made with the aim of improving the catalyst performance such as the raw material conversion rate and selectivity of these reactions. For example, in Patent Document 1, in the molybdenum-bismuth composite oxide catalyst, each raw material component is not uniformly dispersed, but the molybdenum component uses a water-soluble raw material, and the bismuth component uses a water-insoluble raw material. A production method in a heterogeneous system is described. The purpose is explained to avoid a decrease in catalyst performance due to the use of a large amount of nitrate or the like when the bismuth component is a water-soluble nitrate. In this case, it is described that components such as molybdenum and bismuth are solidified and integrated by thermal diffusion in the firing step which is the final step.

Patent Document 2 discloses that the activity, selectivity, and catalyst life of a molybdenum-bismuth-based composite oxide catalyst are related to the amount of nitrate radical in the raw material mixture aqueous solution of the catalyst component at the time of preparation. . And in order to improve catalyst performance, the nitrate radical amount in the raw material mixture aqueous solution at the time of catalyst preparation is reduced, specifically, the ratio of the content of NO ₃ / Mo is set to 1.8 or less. Has been.

  Furthermore, Patent Document 3 discloses a method for producing molybdenum, bismuth, iron, cobalt and / or nickel-based composite oxide catalysts. There, a catalyst precursor powder containing components such as molybdenum, iron, cobalt and / or nickel is prepared in advance, and a bismuth component is mixed and integrated into the obtained catalyst precursor powder, followed by drying and firing. It has been proposed that high performance catalysts be produced.

However, these molybdenum-bismuth complex oxide catalysts according to the prior art still have insufficient catalyst performance such as raw material conversion and selectivity, and further improvement in catalyst performance is required.
Japanese Patent Publication No. 5-87299 JP 2000-325795 A JP 2003-205240 A

  In view of the prior art as described above, the object of the present invention is to favorably produce a corresponding unsaturated aldehyde and unsaturated carboxylic acid in a high yield with good reproducibility by gas phase catalytic oxidation of an olefin with a molecular oxygen-containing gas. The object is to provide a method for producing a catalyst that can be produced.

As a result of diligent research to solve the above-mentioned problems, the present inventors have found that a composite oxide catalyst containing at least (A) molybdenum, (B) bismuth, (C) cobalt and / or nickel, and (D) iron. In the production method, a catalyst precursor powder produced by drying an aqueous dispersion containing the component (A) raw material, the component (C) raw material, and the component (D) raw material, and heat-treating the dried product, In the case of producing a composite oxide catalyst by integrating the component (B) raw material in an aqueous solvent and drying and calcining the integrated product, the nitrate radical (NO ₃ ) contained in the aqueous dispersion is used. It has been found that a catalyst having excellent characteristics can be produced by controlling the content of the nitrate radical within a predetermined range.

Thus, the gist of the present invention is the configuration having the following characteristics.
1. (A) Molybdenum, (B) Bismuth, (C) Cobalt and / or used in the production of the corresponding unsaturated aldehyde and unsaturated carboxylic acid by vapor phase catalytic oxidation of olefin with molecular oxygen-containing gas, respectively. Alternatively, in the method for producing a composite oxide catalyst containing at least nickel and (D) iron, the (A) component raw material, the (C) component raw material, and the (D) component raw material are integrated, and the nitrate radical An aqueous dispersion satisfying the following formula (1) is dried, and the catalyst precursor powder produced through the previous step of heat-treating the dried product and the component (B) raw material in an aqueous solvent And the integrated product is dried and calcined.

1.2 ≦ NO ₃ / (3 × Fe + 2 × (Co + Ni)) (1)

However, in the formula, NO ₃ , Fe, Co, and Ni represent the molar contents of nitrate radical, iron, cobalt, and nickel in the aqueous dispersion, respectively.
2. 2. The method for producing a composite oxide catalyst according to 1 above, wherein a nitrate compound is added to the aqueous dispersion in the preceding step.
3. 3. The method for producing a composite oxide catalyst according to 1 or 2 above, wherein the component (B) raw material is a bismuth compound that is hardly soluble or insoluble in water.
4). 4. The method for producing a composite oxide catalyst according to any one of the above 1 to 3, wherein the content of nitrate radical in the aqueous dispersion in the preceding step satisfies the following formula (2).

1.2 ≦ NO ₃ / (3 × Fe + 2 × (Co + Ni)) ≦ 10 (2)

5). The said complex oxide catalyst, The manufacturing method of the complex oxide catalyst in any one of said 1-4 represented by following General formula (3).

MoaBibCocNidFeeXfYgZhQiSijOk (3)

However, X shows at least 1 type chosen from the group which consists of Na, K, Rb, Cs, and Tl, Y shows at least 1 type chosen from the group which consists of B, P, As, and W, Z shows Mg, Ca, At least one selected from the group consisting of Zn, Ce and Sm is shown. Q represents halogen, and a to k represent atomic ratios of the respective elements. When a = 12, b = 0.5 to 7, c = 0 to 10, d = 0 to 10, c + d = 1 to 10, e = 0.05 to 3, f = 0.0005 to 3, g = 0 to 3, h = 0 to 1, i = 0 to 0.5, j = 0 to 40 In addition, k is a value that satisfies the oxidation state of other elements. )
6). A method for producing acrolein and acrylic acid by vapor-phase catalytic oxidation of propylene with a molecular oxygen-containing gas in the presence of the composite oxide catalyst obtained by the production method according to any one of 1 to 5 above.

  According to the method of the present invention, the olefin conversion rate and the target product used in producing the corresponding unsaturated aldehyde and unsaturated carboxylic acid by vapor phase catalytic oxidation of olefin with molecular oxygen-containing gas, respectively. Provided is a method for producing a composite oxide catalyst having at least excellent selectivity with respect to (A) molybdenum, (B) bismuth, (C) cobalt and / or nickel, and (D) iron.

In the present invention, it is not necessarily clear why the performance of the catalyst is improved by controlling the amount of nitrate radical (NO ₃ ) within the above range, but the catalyst precursor powder prepared by the previous step is more It is estimated that the target catalyst is stabilized and the target catalyst can be obtained more preferably with good reproducibility.

The catalyst produced according to the present invention is a composite oxide catalyst containing at least (A) molybdenum, (B) bismuth, (C) cobalt and / or nickel, and (D) iron. There is no particular limitation as long as it is a composite oxide catalyst containing such components, but among them, a catalyst represented by the following general formula (3) can be preferably applied.

MoaBibCocNidFeeXfYgZhQiSijOk (3)

X, Y, Z, a, b, c, d, e, f, g, h, i, and j in the above general formula are as defined above. Among these, in the present invention, Q is preferably a chlorine atom, and when a = 12, b = 0.5 to 7, c = 0 to 10, d = 0 to 10, c + d = 1. 10 to e, 0.05 to 3, f = 0.005 to 3, g = 0 to 3, h = 0 to 1, i = 0 to 0.05, and j = 0 to 48 are particularly preferable.

  The catalyst having the above composition of the present invention comprises drying a dispersion obtained by integrating the component (A) raw material, the component (C) raw material, and the component (D) raw material in an aqueous medium system, and subjecting the dried product to a heat treatment. It is manufactured by integrating the catalyst precursor powder manufactured through the previous step, the component (B) raw material and the aqueous medium system, and drying and firing the integrated product.

  In the present invention, “integration” of each component raw material means that an aqueous solution or aqueous dispersion of raw material compounds of each component is mixed or aged in a batch or stepwise, or mixed and aged. That is, (a) a method of mixing each of the above component raw material compounds at once, (b) a method of mixing the above respective component raw material compounds at the same time, and aging treatment, (c) each of the above component raw material compounds (D) a method of stepwise mixing, (d) a method of repeating each component raw material compound stepwise mixing / aging process, and a method of combining (a) to (d). Here, aging refers to an operation for obtaining a desired physical property and / or chemical property by treatment under a specific condition such as a constant temperature for a certain period of time. Here, the fixed time is usually in the range of 10 minutes to 24 hours, and the fixed temperature is usually in the range of room temperature to the boiling point of the aqueous solution or aqueous dispersion, preferably 10 to 95 ° C.

  Thus, as a specific method in the preceding step, for example, a mixture of an iron compound and a nickel compound and / or a cobalt compound is added to an aqueous solution of a molybdenum compound, and, if necessary, an X component-containing compound, The Y component-containing compound, the Z component-containing compound, the Q component-containing compound, and other component-containing compounds other than bismuth such as silica are added, and the above-described integration treatment is performed in an aqueous medium.

In the present invention, it is necessary that the nitrate radical content contained in the aqueous dispersion containing the respective component raw materials in such a previous step satisfies the following formula (1). In the _formula, NO 3, Fe, Co, and Ni, respectively, showing nitrate, iron, cobalt, and the molar content of nickel.

1.2 ≦ NO ₃ / (3 × Fe + 2 × (Co + Ni)) (1)

In the present invention, when the value on the right side including the nitrate radical, iron and nickel contents in the formula (1) is smaller than 1.2, the effect of the present invention cannot be sufficiently obtained. Among them, the value on the right side is preferably 1.3 or more, particularly preferably 1.5 or more. On the other hand, even when the value on the right side is excessively large, further effects cannot be obtained. In this case, a large amount of a nitrate group-containing compound and water is added, which is economically disadvantageous for catalyst production. Therefore, the right side value is preferably 50 or less, particularly preferably 10 or less.

  In the present invention, in order to control the content of nitrate radicals contained in the aqueous dispersion in the previous step to the above range, usually, a nitrate compound is preferably used as each catalyst component raw material, or water. Preferably, a thermally decomposable nitrate, preferably ammonium nitrate is added to the dispersion.

  The slurry-like aqueous dispersion obtained by integrating the catalyst component raw materials in the previous step is sufficiently stirred and then dried. There is no particular limitation on the drying method and the state of the resulting dried product, and for example, a powdered dried product may be obtained using a normal spray dryer, slurry dryer, drum dryer, etc. A block-shaped or flake-shaped dried product may be obtained using a mold dryer or a tunnel-type firing furnace.

  The dried granule or cake is heat-treated in air at a temperature of 200 to 400 ° C, preferably 250 to 350 ° C. There are no particular limitations on the type and method of the furnace at that time, and for example, it may be heated with a dry matter fixed using a normal box-type furnace, tunnel-type furnace, etc., or a rotary kiln. It is possible to heat the dried product while flowing it.

  In the present invention, the catalyst precursor powder obtained in the preceding step and the bismuth raw material compound are then integrated in an aqueous medium. At this time, it is preferable to add a basic substance such as ammonia to the aqueous medium so that the slurry is stabilized preferably at 0.01 to 20% by weight. The bismuth raw material compound is preferably a compound that is hardly soluble or insoluble in water, and the bismuth raw material compound is preferably used in the form of a powder. The catalyst precursor powder and the bismuth raw material compound may be particles having a large diameter, but are preferably small particles in order to efficiently promote the thermal diffusion reaction between the particles in the subsequent firing step. Thus, these raw material compounds are preferably pulverized to preferably have an average particle size of 0.1 to 1000 μm.

  Next, the obtained slurry is sufficiently stirred and then dried. The dried product thus obtained is shaped into an arbitrary shape by a method such as extrusion molding, tableting molding or support molding. Next, this is preferably subjected to a final heat treatment at a temperature of 450 to 600 ° C., preferably for about 1 to 16 hours. In this way, a composite oxide catalyst that is highly active and provides the desired oxidation product in high yield is obtained.

Next, the specific example of the manufacturing method of the complex oxide catalyst by this invention is shown. First, an iron, cobalt, and nickel compound are added to an appropriate molybdenum compound, preferably an ammonium molybdate solution, and each nitrate solution is preferably added. Further, if necessary, sodium, potassium, rubidium, thallium, boron, phosphorus, arsenic and / or tungsten compounds are preferably added as respective water-soluble salts or aqueous solutions thereof. More preferably, ammonium nitrate is added as an aqueous solution, and NO ₃ in the aqueous solution is adjusted to the above-described range of the present invention. Add more silica. Next, the obtained slurry is sufficiently stirred and then dried. The dried granule or cake is preferably heat-treated in air at a temperature of 200 to 400 ° C., particularly preferably 250 to 350 ° C., preferably for 0.1 seconds to 24 hours.

  Next, the obtained heat-treated product is dispersed in water, and preferably after adding aqueous ammonia, bismuth compound powder is added. As the bismuth compound powder, (1) at least one of bismuth oxide or bismuth carbonate, (2) bismuth carbonate in which Na is dissolved, (3) Bi and X component (X is the same as defined above) A composite carbonate compound or (4) a composite carbonate compound of Bi, Na and X containing Na and X components is preferred.

  Next, the obtained slurry is sufficiently stirred and then dried. The dried product thus obtained is molded into an arbitrary shape by a method such as extrusion molding, tableting molding or support molding. Next, the molded product is preferably fired in air, preferably at a temperature of 450 to 600 ° C., preferably for about 1 to 16 hours.

The specific surface area, average pore diameter, and pore volume of the composite oxide catalyst produced in the present invention are within the range of the existing catalyst and are not particularly limited, but the specific surface area is 5 to 25 m, respectively. ² / g, the average pore diameter is preferably 0.03 to 1 μm, and the pore volume is preferably 0.2 to 0.7 cc / g.

  In the present invention, means for producing a corresponding unsaturated aldehyde and unsaturated carboxylic acid by gas phase oxidation using olefins described above using molecular oxygen or a molecular oxygen-containing gas, respectively, is an existing method. Can be performed. For example, a fixed bed tube reactor is used as the reactor. In this case, the reaction may be a single flow method or a recycle method through the reactor, and can be carried out under conditions generally used for this type of reaction.

For example, a mixed gas composed of 1 to 15% by volume of propylene, 3 to 30% by volume of molecular oxygen, 0 to 60% by volume of water vapor, 20 to 80% by volume of an inert gas such as nitrogen or carbon dioxide, It introduce | transduces into the catalyst layer with which each 15-50 mm reaction tube was filled at 250-450 degreeC and the pressure of 0.1-1 Mpa, and the space velocity (SV) 300-5000 hr < ^-1 >. Moreover, in this invention, in order to raise productivity more, it can also drive | operate also on high load reaction conditions, for example, the conditions of higher raw material concentration or high space velocity.

EXAMPLES The present invention will be described in more detail below with reference to examples of the present invention, but the present invention should not be construed as being limited to such examples. In the following, the definitions of propylene conversion rate, acrolein yield, acrylic acid yield, and total yield are calculated by the following equations, respectively.

Propylene conversion rate (mol%) = (number of moles of reacted propylene / number of moles of supplied propylene) × 100
Acrolein yield (mol%) = (mol number of produced acrolein) / mol number of supplied propylene) × 100
-Yield of acrylic acid (mol%) = (number of moles of acrylic acid produced) / number of moles of propylene supplied) x 100
Total yield (mol%) = acrolein yield (mol%) + acrylic acid yield (mol%)

Example 1
(Preparation of composite oxide catalyst)
94.1 g of ammonium paramolybdate was dissolved in 400 ml of pure water by heating. Next, 7.18 g of ferric nitrate, 38.7 g of cobalt nitrate and 25.8 g of nickel nitrate were heated and dissolved in 60 ml of pure water. These solutions were gradually mixed with thorough stirring.
Next, 0.85 g of borax and 0.36 g of potassium nitrate were dissolved in 40 ml of pure water under heating and added to the slurry. Next, 19.9 g of ammonium nitrate was dissolved in 20 ml of pure water under heating and added to the slurry. Next, 64 g of silica was added and stirred thoroughly.
The slurry was heat-dried and then subjected to a heat treatment at 300 ° C./1 hour in an air atmosphere.
The obtained granular solid was pulverized and dispersed in 150 ml of pure water by adding 10 ml of aqueous ammonia. Next, 58.1 g of bismuth subcarbonate in which Na was dissolved in 0.52% was added and mixed with stirring.
After drying this slurry by heating, the resulting granular solid was formed into tablets with a diameter of 5 mm and a height of 4 mm using a small molding machine, and then calcined at 500 ° C. for 4 hours to obtain a catalyst. It was.
The catalyst calculated from the charged raw materials is a complex oxide having the following atomic ratio.
Mo: Bi: Co: Ni: Fe: Na: B: K: Si = 12: 5: 3: 2: 0.4: 0.4: 0.2: 0.08: 24
Moreover, the ratio of the molar amount of nitrate radicals and the molar amounts of Fe, Co and Ni in the aqueous dispersion of the previous step calculated from the charged raw materials was as follows.
NO ₃ /(3×Fe+2×(Co+Ni))=1.51

(Propylene oxidation reaction)
20 ml of the composite oxide catalyst prepared as described above was filled into a stainless steel nighter jacketed reaction tube with an inner diameter of 15 mm, and a raw material gas having a propylene concentration of 10%, a steam concentration of 17%, and an air concentration of 73% was brought to normal pressure. Then, the reaction was conducted at a reaction bath temperature of 305 ° C. and a contact time of 1.8 seconds to carry out an oxidation reaction of propylene. As a result, the propylene conversion rate, acrolein yield, and acrylic acid yield shown in Table 1 were obtained.

Comparative Example 1
In Example 1, it carried out similarly except not adding ammonium nitrate, and manufactured the complex oxide catalyst of the same composition as Example 1. The ratio of the molar amount of nitrate radical and the molar amount of Fe, Co, and Ni in the aqueous dispersion of the previous step calculated from the charged raw materials was as follows.
NO ₃ /(3×Fe+2×(Co+Ni))=1.01
The oxidation reaction of propylene was carried out in the same manner as in Example 1, and the obtained results are shown in Table 1.

Example 2
94.1 g of ammonium paramolybdate was dissolved in 400 ml of pure water by heating. Next, 7.18 g of ferric nitrate, 38.7 g of cobalt nitrate and 25.8 g of nickel nitrate were heated and dissolved in 60 ml of pure water. These solutions were gradually mixed with thorough stirring.
Next, 0.85 g of borax and 0.36 g of potassium nitrate were dissolved in 40 ml of pure water under heating and added to the slurry. Next, 79.6 g of ammonium nitrate was dissolved in 80 ml of pure water under heating and added to the slurry. Next, 64 g of silica was added and stirred thoroughly. The slurry was heat-dried and then subjected to a heat treatment at 300 ° C./1 hour in an air atmosphere.
The obtained granular solid was pulverized and dispersed in 150 ml of pure water by adding 10 ml of aqueous ammonia. Next, 58.1 g of bismuth carbonate in which 0.52% of Na was dissolved was added and mixed with stirring.
After drying this slurry by heating, the resulting granular solid was formed into tablets with a diameter of 5 mm and a height of 4 mm using a small molding machine, and then calcined at 500 ° C. for 4 hours to obtain a catalyst. It was.
The catalyst calculated from the charged raw materials is a complex oxide having the following atomic ratio.
Mo: Bi: Co: Ni: Fe: Na: B: K: Si = 12: 5: 3: 2: 0.4: 0.4: 0.2: 0.08: 24
Moreover, the ratio of the molar amount of the nitrate radical and the molar amount of FeCo and Ni in the aqueous dispersion of the previous step calculated from the charged raw materials was as follows.
NO ₃ /(3×Fe+2×(Co+Ni))=3.01
The oxidation reaction of propylene was carried out in the same manner as in Example 1, and the obtained results are shown in Table 1.

Example 3
94.1 g of ammonium paramolybdate was dissolved in 400 ml of pure water by heating. Next, 7.18 g of ferric nitrate, 38.7 g of cobalt nitrate and 25.8 g of nickel nitrate were heated and dissolved in 60 ml of pure water. These solutions were gradually mixed with thorough stirring.
Next, 0.85 g of borax and 0.36 g of potassium nitrate were dissolved in 40 ml of pure water under heating and added to the slurry. Next, 358.2 g of ammonium nitrate was dissolved in 360 ml of pure water under heating, and added to the slurry. Next, 64 g of silica was added and stirred thoroughly. The slurry was heat-dried and then subjected to a heat treatment at 300 ° C./1 hour in an air atmosphere.
The obtained granular solid was pulverized and dispersed in 150 ml of pure water by adding 10 ml of aqueous ammonia. Next, 58.1 g of bismuth carbonate in which 0.52% of Na was dissolved was added and mixed with stirring.
After drying this slurry by heating, the resulting granular solid was formed into tablets with a diameter of 5 mm and a height of 4 mm using a small molding machine, and then calcined at 500 ° C. for 4 hours to obtain a catalyst. It was.
The catalyst calculated from the charged raw materials is a complex oxide having the following atomic ratio.
Mo: Bi: Co: Ni: Fe: Na: B: K: Si = 12: 5: 3: 2: 0.4: 0.4: 0.2: 0.08: 24
Moreover, the ratio of the molar amount of the nitrate radical and the molar amount of FeCo and Ni in the aqueous dispersion of the previous step calculated from the charged raw materials was as follows.
NO ₃ /(3×Fe+2×(Co+Ni))=10.01
The oxidation reaction of propylene was carried out in the same manner as in Example 1, and the obtained results are shown in Table 1.

The catalyst produced by the method of the present invention is used to produce a corresponding unsaturated aldehyde and unsaturated carboxylic acid in high yield by gas phase catalytic oxidation of olefin with molecular oxygen-containing gas. The produced unsaturated aldehydes and unsaturated carboxylic acids are used in a wide range of applications as raw materials for various chemicals, monomers for general-purpose resins, monomers for functional resins such as water-absorbing resins, flocculants, and thickeners. The

Claims (6)

(A) Molybdenum, (B) Bismuth, (C) Cobalt and / or used in the production of the corresponding unsaturated aldehyde and unsaturated carboxylic acid by vapor phase catalytic oxidation of olefin with molecular oxygen-containing gas, respectively. Alternatively, in the method for producing a composite oxide catalyst containing at least nickel and (D) iron, the (A) component raw material, the (C) component raw material, and the (D) component raw material are integrated, and the nitrate radical An aqueous dispersion satisfying the following formula (1) is dried, and the catalyst precursor powder produced through the previous step of heat-treating the dried product and the component (B) raw material in an aqueous solvent And the integrated product is dried and calcined.

1.2 ≦ NO ₃ / (3 × Fe + 2 × (Co + Ni)) (1)

However, in the formula, NO ₃ , Fe, Co, and Ni represent the molar contents of nitrate radical, iron, cobalt, and nickel in the aqueous dispersion, respectively.   The method for producing a composite oxide catalyst according to claim 1, wherein a nitrate compound is added to the aqueous dispersion in the preceding step.   The method for producing a composite oxide catalyst according to claim 1 or 2, wherein the component (B) raw material is a bismuth compound that is hardly soluble or insoluble in water. The method for producing a composite oxide catalyst according to any one of claims 1 to 3, wherein the content of nitrate radical in the aqueous dispersion in the preceding step satisfies the following formula (2).

1.2 ≦ NO ₃ / (3 × Fe + 2 × (Co + Ni)) ≦ 10 (2)
The method for producing a composite oxide catalyst according to any one of claims 1 to 4, wherein the composite oxide catalyst is represented by the following general formula (3).

MoaBibCocNidFeeXfYgZhQiSijOk (3)

However, X shows at least 1 type chosen from the group which consists of Na, K, Rb, Cs, and Tl, Y shows at least 1 type chosen from the group which consists of B, P, As, and W, Z shows Mg, Ca, At least one selected from the group consisting of Zn, Ce and Sm is shown. Q represents halogen, and a to k represent atomic ratios of the respective elements. When a = 12, b = 0.5 to 7, c = 0 to 10, d = 0 to 10, c + d = 1 to 10, e = 0.05 to 3, f = 0.0005 to 3, g = 0 to 3, h = 0 to 1, i = 0 to 0.5, j = 0 to 40, K is a value that satisfies the oxidation state of other elements. )   A method for producing acrolein and acrylic acid by vapor-phase catalytic oxidation of propylene with a molecular oxygen-containing gas in the presence of the composite oxide catalyst obtained by the production method according to claim 1.