JP2001058827A - Production of compound oxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a compound oxide, by which the compound oxide useful as a catalyst having good performances such as good objective compound selectivity and a good production rate can simply be obtained, by applying an oxidation-reduction reaction to raw materials for the compound oxide containing at least Mo and V in a liquid meditun at a specific pressure and at a specified temperature, removing the liquid medium and then drying the residue. SOLUTION: At least one of the raw compounds for the elements is preferably soluble in a liquid medium to improve the yield of the objective compound oxide. Water is most preferably as the liquid medium. Accordingly, a water-soluble Mo compound is preferable as the Mo raw material compound. The V raw material compound is preferably a water-soluble V compound, more preferably a V compound in which the average valency of V is >=4+ and <=5+. The raw material compounds and other element raw compounds are charged in water in prescribed amounts, respectively, to prepare an aqueous raw material mixture, which is subjected to an oxidation-reduction reaction. The temperature of the reaction is not higher than the boiling point of water, preferably 50 to 90 deg.C, and the pressure of the reaction is <=5 atm, preferably <=1 atm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to at least Mo, V
And a novel method for producing a composite oxide containing Te and / or Sb. The composite oxide is useful as a catalyst for gas-phase oxidation, particularly as a catalyst for gas-phase oxidation and ammoxidation of lower hydrocarbons.

[0002]

2. Description of the Related Art Mo, V, Te, O or Mo, V, S
A composite metal oxide catalyst containing b and O as essential components is known as a catalyst for gas phase selective oxidation of lower saturated hydrocarbons. For example, as a catalyst effective for producing acrylonitrile by an ammoxidation reaction of propane, JP-A-5-20813
In JP-A No. 6-157241, a catalyst containing Mo, V, Te, and O as essential components is disclosed.
A catalyst containing Sb and O as essential components is disclosed.

As a catalyst effective for producing acrylic acid by a gas phase oxidation reaction of propane, JP-A-6-2793 is known.
No. 51, JP-A-7-10801, JP-A-8-801
In 196626, a catalyst containing Mo, V, Te, and O as essential components is disclosed in JP-A-9-316023, JP-A-10-045664, and JP-A-10-11849.
No. 1, JP-A-10-120617, JP-A-10-120617
JP-A-137585 discloses a catalyst containing Mo, V, Sb, and O as essential components. Further, as a catalyst effective for the production of ethylene by vapor phase oxidation of ethane, JP-A-7-53414 discloses a catalyst containing Mo, V, Te, and O as essential components. A catalyst containing Mo, V, Sb, and O as essential components is disclosed.

[0004] With regard to these conventionally known catalysts containing Mo, V, Te, O or Mo, V, Sb, O as an essential component, oxalic acid and oxalate are contained in the raw material compound, and when the catalyst is calcined. By treating them at a high temperature, an oxidation-reduction reaction with each metal component as a catalyst component is caused, thereby successfully obtaining an effective catalyst. On the other hand,
JP-A-6-45815 discloses that in a catalyst containing VPO as a basic component, a vanadium-phosphorus crystalline oxide having a high purity at a relatively low temperature is formed by a reaction with a reducing substance in an aqueous medium. It is disclosed that by calcination at a high temperature, a highly active and highly selective catalyst effective for producing maleic anhydride by gas-phase oxidation of butane can be obtained. However, a catalyst containing Mo, V, Te, O or Mo, V, Sb, O as an essential component is a multi-component, and since each component can have various valences, it is oxidized in a liquid medium. It is considered difficult to control the degree of reduction, and it has been considered difficult to prepare a catalyst effective for the above-described gas phase oxidation reaction.

[0005]

According to the above-mentioned publication relating to a catalyst containing Mo, V, Te, O or Mo, V, Sb, O as an essential component, a composite metal oxide catalyst having sufficient performance is prepared. Therefore, it is necessary to perform a treatment at a high temperature including a complicated oxidation-reduction process, and it is difficult to adjust the amount of the reducing agent to obtain an optimal catalyst, that is, to control the degree of oxidation-reduction. In the redox process at high temperature, C
Explosive decomposition components such as O are released. Therefore, an apparatus and a process for removing explosive gas are required, and an improvement for efficiently producing a catalyst has been required. Furthermore, although the catalysts prepared by these conventional methods have sufficiently high catalytic performance, even higher performance is required for industrial use. The present invention provides at least Mo and V
In order to efficiently synthesize a desired catalyst in a complex oxide catalyst system containing Te and / or Sb, the redox degree of the system is controlled in advance by a redox reaction under specific conditions. Then, by subjecting the resultant to drying and baking treatment, it is an object to easily obtain a catalyst having good performance such as selectivity of a target substance and a production rate.

[0006]

Means for Solving the Problems The present inventor has repeatedly studied a method for synthesizing a composite metal oxide containing at least Mo and V while taking the above-mentioned problems into consideration.
It has been found that a composite oxide containing at least Mo and V can be efficiently synthesized by performing a drying treatment after controlling the degree of oxidation-reduction of the elements in the catalyst by an oxidation-reduction reaction in a liquid medium. The present inventors have found that the composite oxide prepared by the production method of the present invention exhibits extremely excellent performance as a catalyst, and reached the present invention.

That is, the gist of the present invention is that at least M
After subjecting the raw compound of the composite oxide containing o and V to an oxidation-reduction reaction in a liquid medium at a pressure of 5 atm or less at a temperature not higher than the boiling point of the liquid medium, the liquid medium is removed and dried. The present invention relates to a method for producing a composite oxide.

According to the manufacturing method of the present invention, at least Mo
And V, for example, a complex oxide of the following formula [1] can be efficiently prepared, and a complex oxide of the formula [1]
A high-performance catalyst can be easily prepared even when component x selected from the elements described as X in a wide range is contained.
Further, in the gas phase selective oxidation of lower saturated hydrocarbons, the catalyst prepared by the production method of the present invention has a higher yield and selectivity of the target product than a catalyst prepared by a conventionally known technique, It is characterized by high substrate conversion activity per specific surface area.

[0009]

Embedded image

(Where X is Ti, Zr, Nb, Ta, C
r, W, Mn, Fe, Ru, Co, Rh, Ir, Ni,
Pd, Pt, Cu, Ag, Zn, In, Sn, Pb, B
represents one or more elements selected from i, Ge, S and Ce, and 0.01 ≦ a <1.0, 0 ≦ b ≦ α, 0 ≦ x
<1.0, 0.01 ≦ α / (1 + a + x) ≦ 0.50,
0 ≦ y ≦ (1 + a + α + x), where n is a number determined by the oxidation state of another element. )

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, it is necessary that the raw material compounds of each element for producing the composite oxide are present in a state of being dispersed or dissolved in a liquid medium before the oxidation-reduction reaction. In order to produce the target composite oxide with good yield, it is preferable that at least a part of the raw material compound of each element is soluble in the liquid medium. Examples of the solvent include water, an organic solvent, and a mixture thereof. Among them, a solvent mainly composed of water, for example, a solvent containing 50% by weight or more of water is most preferable.

As the raw material compound of each element used in the present invention, the Mo raw material is usually a compound containing Mo, at least part of which is soluble in water, preferably a water-soluble compound containing Mo. More preferably, a water-soluble compound containing Te and Mo, a water-soluble compound containing Sb and Mo, or a water-soluble compound capable of producing them under the preparation conditions, and particularly preferably a heteropolyanion containing Te and Mo Or a water-soluble compound having a heteropolyanion containing Sb and Mo, or a water-soluble compound capable of producing them under the preparation conditions, most preferably a water-soluble compound having an Anderson-type Te-Mo heteropolyanion. Compound or water-soluble compound having Anderson-type Sb-Mo heteropolyanion, or preparation conditions In a water-soluble compound capable of producing them. These heteropolyanions may be partially reduced.

Anderson type Te-Mo heteropolyani
On and Anderson type Sb-Mo heteropolyanio
(Hereinafter collectively referred to as “Anderson-type heteropolyanio”
May be substituted with V for Mo)
No. Of compounds having Anderson-type heteropolyanions
The cation is usually an ammonium cation,
Luammonium cation, H +, alkali metal cation
And the like, preferably an ammonium cation,
Combinations of ammonium cations and H + are used.
Here, the Anderson-type Te-Mo heteropolyanion
Is (TeMo_6-kV_kO_{twenty four})^{(6 + k)-}(K is 0 or 1
A heteropolyanion having a structure of
Anderson type Sb-Mo heteropolyanion
Is (SbMo _6-l V_lO_{twenty four} ^{(7 + l)-}(L is 0 or 1
A heteropolyanion having the following structure:

Specifically, (TeMo ₆ O ₂₄ ) (N
_{H 4) 6, (TeMo 5} V 1 O 24) (NH 4) 7, (T
Anderson type T such as eMo ₆ O ₂₄ ) H (NH ₄ ) ₅
a compound containing an e-Mo heteropolyanion, (SbMo
_{6-l V1 O 24) (} NH 4) 7, (SbMo 5 V 1 O
_{24) (NH 4) 8,} (SbMo 6 O 24) H (NH 4) 6,
Such as a compound containing an Anderson type Sb-Mo heteropolyanion, ammonium paramolybdate, MoO ₂
Molybdenyl acetylacetonate represented by (acac) ₂ (acac is CH ₃ COCHCOC
H ₃ ^(-) ), molybdenum halide, J. Zubi
Review by eta, MolecularEngineee
ring, Vol. 3, 93-120 (1993) and C
orientation Chemistry Rev
ies, Vol. 114 107-167 (199
The molybdenum compound group shown in 2) can be used, but a compound containing an Anderson-type heteropolyanion and ammonium paramolybdate are preferably used. These Mo raw materials may be used alone or in combination of two or more.

The Te raw material is usually a compound containing Te which is at least partially soluble in water, preferably a water-soluble compound containing Te, and more preferably Te and Mo.
And particularly preferably Te and M
a water-soluble compound having a heteropolyanion containing o,
Alternatively, it is a water-soluble compound capable of producing them under the preparation conditions, most preferably a water-soluble compound having an Anderson-type Te-Mo heteropolyanion, or a water-soluble compound capable of producing them under the preparation conditions. These heteropolyanions may be partially reduced. In the Anderson type Te-Mo heteropolyanion, Mo may be partially substituted with V.

Specifically, (TeMo ₆ O ₂₄ ) (NH ₄ )
_{6, (TeMo 5 V 1 O} 24) (NH 4) 7, (TeM
Anderson type Te-M such as o ₆ O ₂₄ ) H (NH ₄ ) ₅
o A compound containing a heteropolyanion, telluric acid, tellurium dioxide, tellurium trioxide, Te metal, tellurium halide and the like can be used, and preferably Anderson type Te-Mo
A compound containing a heteropolyanion, telluric acid, tellurium dioxide, more preferably an Anderson Te-Mo heteropolyanion, telluric acid is used. These Te raw materials may be used alone or in combination of two or more.

The Sb raw material is usually a compound containing Sb, at least part of which is soluble in water, preferably a water-soluble compound containing Sb, more preferably Sb and Mo.
And particularly preferably Sb and M
a water-soluble compound having a heteropolyanion containing o,
Alternatively, it is a water-soluble compound capable of forming them under the preparation conditions, most preferably a water-soluble compound having an Anderson-type Sb-Mo heteropolyanion, or a water-soluble compound capable of forming them under the preparation conditions. These heteropolyanions may be partially reduced. In the Anderson type Sb-Mo heteropolyanion, Mo may be partially substituted with V.

Specifically, (SbMo _6-l V ₁ O ₂₄ )
(NH ₄ ) ₇ , (SbMo ₅ V ₁ O ₂₄ ) (NH ₄ ) ₈ ,
(SbMo ₆ O ₂₄ ) H (NH ₄ ) ₆ and other compounds containing an Anderson-type Sb-Mo heteropolyanion, antimony oxide sol, Sb ₂ O ₃ , Sb ₂ O ₅ , antimony halide, antimony sulfate, antimonyl tartrate Ammonium or the like can be used, but a compound containing an Anderson-type heteropolyanion is preferably used. These Sb raw materials may be used alone or in combination of two or more.

The V raw material is a compound containing V, preferably at least part of which is soluble in water, preferably a water-soluble compound containing V. More preferably, the average valence of V is 4+ or more and 5+ or less. A compound consisting of V or a combination of a plurality of V compounds such that the average valence of V is 4+ or more and 5+ or less. Examples of such a compound include a raw material having a valence of 5+, such as ammonium metavanadate or V ₂ O ₅ ; Review by Zubieta, Molecul
ar Engineering, Vol. 3,93-1
20 (1993) and Coordination Che
mysteryReviews, Vol. 114 107
-167 (1992), vanadyl oxalate, vanadyl sulfate, vanadyl nitrate, VO
Vanadyl acetylacetonate represented by (acac) ₂ (acac represents CH ₃ COCHCOCH ₃ ⁽⁻⁾ ), VCl _{4 and the} like.

Component X in the general formula [1] is Ti, Zr,
Nb, Ta, Cr, W, Mn, Fe, Ru, Co, R
h, Ir, Ni, Pd, Pt, Cu, Ag, Zn, I
one or more elements selected from n, Sn, Pb, Bi, Ge, S and Ce, preferably one or more elements selected from Ti, Nb, Ta and W, more preferably Nb
And / or Ta is used. The raw material X does not need to be particularly water-soluble as long as it has good dispersibility in water. However, it is preferably a water-soluble compound. Alternatively, salts thereof, carboxylate salts, ammonium carboxylate salts, alkoxides, acetylacetonates, and the like can be used.

The NH ₄ raw material is not particularly necessary, but when it is used, an ammonium salt of the raw material compound of each of the above elements or aqueous ammonia may be used. Ammonium salts are preferred. This N
Most of the H ₄ component is generally removed through a firing step. These Mo, V, Te, Sb, X, NH ₄
The raw material compound is usually 1 to 50% by weight, preferably 10 to 30% by weight, based on the weight of the resulting complex oxide of the formula [1] in water at room temperature to 90 ° C. The mixture is charged and stirred to obtain an aqueous raw material mixture. The state of each raw material in the aqueous raw material mixture may be a water slurry or an aqueous solution, but is more preferably an aqueous solution. The pH of the obtained aqueous raw material mixture may be adjusted if necessary.

As the raw material compound of the composite oxide of the present invention, if at least one component, or at least a part thereof, is a compound that is soluble in water, the other component is a compound that is insoluble or hardly soluble in water. Is also good. When a compound insoluble or hardly soluble in water is used as the metal raw material, preferably, at least a part of the Mo raw material and / or the V raw material is a compound soluble in water, and the Te raw material and / or the Sb raw material is insoluble in water. Or a combination of hardly soluble compounds.

The reason why a compound insoluble or hardly soluble in water can be used as a raw material is not clear, but even a very small amount of a compound insoluble or hardly soluble in water is dissolved in water, The dissolved equilibrium of a compound insoluble or hardly soluble in water moves by dissolving at least a part of the dissolved compound with a water-soluble compound and shifting the dissolution equilibrium of water insoluble or hardly soluble compound to water. The compound moves and insoluble or hardly soluble in water sequentially dissolves, or a compound that is at least partially soluble in water reacts with a compound that is insoluble or hardly soluble in water on the surface thereof. It is presumed that the compound is dissolved in a water-soluble compound. Of these raw material compounds, compounds that are at least partially soluble in water are usually dissolved in 100 g of water at room temperature.
Compounds having a solubility of 01 g or more are mentioned, and compounds insoluble or poorly soluble in water are usually 100 g at room temperature.
Compounds having a solubility of less than 0.01 g in water.

The ratio of each component used as a starting compound is as follows:
Usually, the ratio is set to be the same as the ratio of the obtained composite oxide of the formula [1]. As for the composition of each element of the target composite oxide of the formula [1], when the number of moles of Mo is 1.0, the molar ratio (a) of V is 0.01 or more and less than 1.0, and is preferably Is 0.1 or more and less than 0.6, and more preferably 0.1.
2 or more and less than 0.5. When the Mo mole number is 1.0, the molar ratio (x) of X is 0 or more and less than 1.0, preferably 0.02 or more and less than 0.30, and more preferably 0.03 or more and 0.25 or less. Is less than. The molar ratio of the total amount (α) of Te and Sb to the total amount (1 + a + x) of Mo, V, and X is 0.01 or more and 0.50 or less, preferably 0.03 or more and 0.25 or less. . The molar ratio of Te or Sb is preferably 0 or more and less than 0.5, and more preferably 0.02 or more and less than 0.3 when the Mo mole number is 1.0. Also,
When the number of moles of V is 1.0, the molar ratio of X is preferably 0.03 or more and less than 3.0, and more preferably 0.06 or less.
It is more than 1.5.

The amount (y) of ammonium ions in the formed composite oxide of the formula [1] varies depending on the production conditions, particularly the temperature and pH, but the total amount of Mo, V, Te, Sb and X (1 + a + α + x Is usually 0 or more and 1.
0 or less. The present invention is characterized in that after the above-mentioned raw material compound is subjected to an oxidation-reduction reaction in a liquid medium, the solvent is removed and dried. The oxidation-reduction reaction in this case may be an oxidation-reduction reaction between raw material compounds, an oxidation-reduction reaction between a raw material compound and a substance separately added to a medium containing the raw material compound, or an electrochemical redox reaction. In the former case, the oxidation-reduction degree of the entire raw material compound system does not change before and after the reaction, but the oxidation-reduction degree of each raw material changes before and after the reaction, and in the latter case, the oxidation of each raw material In addition to the fact that the degree of reduction changes before and after the reaction, it means that the degree of oxidation reduction of the entire raw material compound system changes before and after the reaction.

In the present invention, a method in which the redox degree of the entire raw material compound system is reduced by the redox reaction, as in the latter case, is preferably used because the control of the redox degree is easy and simple. Specifically, a substance having a reducing action is preferably present in the medium containing the raw material mixture. By the presence of a substance having a reducing action in the medium containing the raw material mixture, the degree of reduction of the system is increased, and at the same time, M
It is possible to control the valences of o, V, Te, Sb, and X, that is, to control the degree of redox of the system. The amount of the substance having a reducing action to be present in the medium containing the raw material mixture is the average metal valence of the target and the average metal valence of the charge,
And its reduction efficiency, it is not possible to unconditionally determine a suitable amount thereof, but it is usually 0.001 mole times or more and 20.0 mole times or less with respect to the total number of moles of metal charged. Preferably 0.01 mol times or more 1
It is added, for example, at a ratio of 0.0 mole times or less.

The type of the reducing substance is not particularly limited as long as it is a substance having a reducing property at a temperature not higher than its boiling point in a liquid medium to the starting compound or a part thereof. Such inorganic amines and salts thereof, inorganic hydrazines such as hydrazine and salts thereof, and diimides are usually used. Aldehydes such as aliphatic aldehydes and aromatic aldehydes, alcohols having 7 or less carbon atoms such as butanols, benzyl alcohols and acetols, reducing carboxylic acids such as oxalic acid, tartaric acid and ascorbic acid, and glucose. Also reducing sugars such as, the raw material compound in a liquid medium,
Alternatively, it can be used when it shows sufficient reducibility to a part thereof. Also, metal pieces such as Fe, Fe (II),
Low-valent metal ions such as Sn (II), metal hydrides and metal hydride complex compounds, borane compounds and phosphorus compounds can also be used. Among them, as the reducing agent, those soluble in a liquid medium are preferable, and the reaction with a substance having a reducing property in the liquid medium proceeds favorably under relatively mild conditions and has a reducing property in order to aggregate. The stronger the reducing power of the substance, the better. Specifically, acetol, hydroxylamine,
Compounds having a reducing power such as hydrazine that can precipitate silver from the Tollens reagent by silver mirror reaction are more preferable than carboxylic acids such as oxalic acid, which does not precipitate silver from the Tollens reagent, isopropanol, and butanol. Here, as a method for testing the reducing power of a substance having a reducing property by a silver mirror reaction, a method usually performed as a silver mirror test can be adopted. That is, a method can be employed in which a sample containing a reducing organic compound is placed in a clean glass container, mixed with a silver nitrate ammonia solution, heated to 50 to 60 ° C., and the presence or absence of silver precipitation is confirmed. Due to the ease of controlling the degree of oxidation-reduction and the ease of maintaining the degree of oxidation-reduction during the subsequent drying and firing treatment, the oxidized and reducing substance has N2.
Inorganic amines such as hydroxylamine and salts thereof which are removed outside the system, and inorganic hydrazines such as hydrazine and salts thereof are desirable. Sulfates such as hydrazine sulfate and hydroxylamine sulfate are particularly preferred. One or two or more substances having a reducing action may be used in combination.

There is no particular limitation on the manner of the oxidation-reduction reaction in the solution, but the above-mentioned raw material mixture is placed in a container and the oxidation-reduction reaction is performed. Alternatively, after a part of the raw material mixture is put into a container and subjected to an oxidation-reduction reaction, the remaining raw material compounds may be added. The raw material mixture or a part thereof may be supplied to the reactor in a form dissolved in a liquid serving as a medium, or a liquid serving as a medium may be added later if necessary. When a reducing substance is present, specifically, there is a method in which the above-described raw material mixture, or a part thereof, is put into a vessel, a reducing substance is added, and the mixture is heated and reacted. It is preferable to add a reducing substance to the raw material mixture or a part of the raw material mixture which has been heated in advance, and to cause a reaction. The form of the reducing substance may be a solid or a liquid, but is preferably added as a liquid or a solution.

There is no particular restriction on the order of mixing the respective raw materials in the above-mentioned raw material mixture and the timing of adding the reducing substance, but it is preferable to add the reducing substance to the mixture containing at least V, more preferably Adds a reducing substance to a mixture in which Mo, V, Te or Sb coexists, particularly preferably Mo, V,
This is a method of adding a reducing substance to a mixture in which Te, Sb, and X coexist. The temperature of the oxidation-reduction reaction is a temperature equal to or lower than the boiling point of the solvent, and is usually 0 ° C or higher and 150 ° C or lower,
Preferably 30 ° C. or higher and 100 ° C. or lower, particularly preferably 5 ° C.
0 ° C or more and 90 ° C or less. The pressure is 5 atm or less, preferably 1 atm or less.

During the oxidation-reduction reaction, stirring may or may not be performed, but it is preferable to perform stirring in order to maintain the homogeneity of the raw materials in the system. The time of the oxidation-reduction reaction depends on the raw materials,
Although it depends on the reaction temperature, the reaction is preferably performed until the oxidation-reduction reaction system reaches equilibrium or until the system is controlled to a desired degree of oxidation-reduction. The processing time of the reduction treatment when a reducing substance is added depends on the raw material, the type of the reducing substance, its reduction efficiency, and the reaction temperature, but usually 1 minute to 6 hours, preferably 10 minutes to 1 hour. It is. When the oxidized reducing agent goes out of the system as a gas, the air bubbles are observed, so that the processing can be completed when the generation of the air bubbles is completed. If necessary depending on the combination of the constituent elements, etc., a reduction treatment divided into multiple times is preferably used.

After completion of the oxidation-reduction reaction, the reaction product is promptly evaporated to dryness and dried, or the liquid component is removed and dried to obtain the composite oxide of the present invention. When a solid substance is generated by an oxidation-reduction reaction, a liquid component and a solid component are separated by filtration or the like, and then dried to obtain a composite metal oxide. The drying method and temperature are not particularly limited, but are usually 50 ° C or more and 250 ° C or less, preferably 70 ° C or more and 200 ° C or less.
° C or lower, particularly preferably 90 ° C or higher and 180 ° C or lower. The atmosphere for drying and the atmosphere for storing the composite oxide obtained after drying are usually air or an atmosphere having an oxygen concentration lower than that of air or under reduced pressure.
ppm or less, more preferably 100 ppm or less, and most preferably in an atmosphere of an inert gas such as nitrogen, argon, helium or the like substantially free of oxygen or in a vacuum. As the type of drying, a box dryer, a spray dryer, a drum dryer, a slurry dryer, or the like is used.
A centrifugal method, a two-fluid nozzle method, a high-pressure nozzle method, or the like is used as a method of atomizing the spray dryer.

Although the exact valence of each component in the solution after the oxidation-reduction reaction is unknown, in the present invention, the valence of each element in the composite oxide obtained by drying after oxidation-reduction is: M
o is 5+ or more and less than 6+ on average, and V is 4+ or more and less than 5+ on average. Te is 0 or more and 6+ or less on average, and Sb is 0 or more and 5+ or less on average. Further, when expressed as an average valence of all metal elements contained in the composite oxide, an average of 4+ to 6+,
The average is preferably 4.5+ or more and 5.9 or less, particularly preferably 5+ or more and 5.8+ or less. The valence in the composite metal oxide can be estimated by X-ray photoelectron spectroscopy.
The progress of the oxidation-reduction reaction of the present invention can also be identified by, for example, changing the color of the slurry containing each raw material compound to black.

When mechanical strength is required depending on the application, a so-called carrier can be mixed in an appropriate amount. Examples of the carrier include silica, alumina, silica alumina, titania, zirconia, and the like. The form of mixing may be an oxide powder, an oxide sol, a gel or an alkoxy. These carriers may be added to any medium before, during or after the oxidation-reduction reaction, or mixed with the composite oxide obtained by drying after the oxidation-reduction reaction, and subjected to calcination described below. good.

The composite oxide thus obtained is further heated and calcined in the gas phase to become a composite oxide used as a catalyst. The degree of crystallinity can be increased by firing, and the mechanical strength can be increased by firing after mixing with the carrier. The firing temperature is 350 ° C or higher,
Preferably it is 550-650 degreeC. The firing time is usually 5 minutes to 20 hours, preferably 1 to 6 hours. The firing atmosphere is usually an atmosphere having an oxygen concentration lower than that of air, preferably an oxygen concentration of 500 ppm or less, more preferably an oxygen concentration of 100 ppm or less, and most preferably an inert gas atmosphere such as nitrogen, argon, or helium, which contains substantially no oxygen. is there. Preliminary firing at 400 ° C. or lower may be performed as necessary.

The composite metal oxide may be further subjected to post-treatment such as pulverization, kneading, molding and impregnation depending on the use. The composite metal oxide obtained according to the present invention has extremely high performance as a catalyst for gas phase oxidation or ammoxidation of lower alkanes. For example, maleic anhydride from n-butane, acrylic acid from propane, acrylonitrile from propane, acrylic acid and acrylonitrile from propane,
It is useful as a catalyst in reactions for producing methacrylic acid from isobutane and ethylene from ethane.

For example, in the case of producing acrylonitrile and / or acrylic acid from propane, the composite oxide catalyst obtained by the method of the present invention is placed in a reactor, the reaction temperature is usually 350 to 500 ° C., and propane / ammonia is used. /
When the molar ratio of oxygen / nitrogen is usually 1.0 / 0.1 to 3.0 /
It is manufactured by supplying a reaction gas having a space velocity SV of 0.1 to 10.0 / 0 to 50.0 to a reaction apparatus at a space velocity SV of usually 100 to 30,000 h ^-1 , preferably 500 to 10,000 h ^-1 . Alkanes to nitriles and α, β
When simultaneously producing unsaturated carboxylic acid, a method for controlling the production ratio of nitrile and α, β unsaturated carboxylic acid will be described below, taking as an example the case where acrylonitrile and acrylic acid are produced simultaneously from propane. .

The control of the production ratio of acrylonitrile and acrylic acid cannot be specified unconditionally because it depends on the conversion of the feedstock and the selectivity of the product, but the following is a rough guide. The production ratio of acrylonitrile and acrylic acid can be controlled by changing the molar ratios of propane, ammonia, and oxygen to be supplied. For example, when the molar ratio of propane / ammonia / oxygen to be supplied is c / d / e, when 2c ≦ e, acrylonitrile can be produced as a main product under the condition of c ≦ d, and usually d ≦ c. Acrylonitrile and acrylic acid can be produced simultaneously under the conditions, and acrylic acid can be produced as a main product under the condition of d = 0. Further, when e ≦ 2c, acrylonitrile can be usually produced as a main product under the condition of e ≦ 2d, acrylonitrile and acrylic acid can be produced simultaneously under the condition of usually 2d ≦ e, and acrylonitrile can be produced usually under the condition of d = 0. Acid can be produced as the main product. In the case where the catalyst is used as a catalyst as described above, particularly when the conversion of the raw material is kept low and a high product selectivity is realized, it is economical to separate and recycle the unreacted raw material at the outlet of the reactor and reuse it as a raw material. It is economically advantageous.

[0038]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples unless it exceeds the gist. W
WH, propane conversion, acrylonitrile yield, propane conversion rate, acrylonitrile selectivity, acrylic acid selectivity, propylene selectivity, acrylonitrile selectivity from ammonia, and acrylic acid yield are calculated as follows.

WWH: mass of supplied propane (kg) per unit time (hr) / mass of catalyst (kg) Space velocity SV: total amount of supplied gas 1 (NTP) per unit time (hr) / capacity of catalyst ( l) Propane conversion: moles of propane reacted / moles of propane supplied Acrylonitrile yield: moles of acrylonitrile produced / moles of propane supplied Propane conversion rate: propane reacted per unit time (hr) Number of moles / surface area of catalyst (m ² / g) Acrylonitrile selectivity: moles of acrylonitrile produced / moles of reacted propane Acrylic acid selectivity: moles of produced acrylic acid / moles of reacted propane ammonia Selectivity for acrylonitrile from water: moles of acrylonitrile formed / moles of reacted ammonia Acrylic acid yield: number of moles of generated acrylic acid / number of moles of supplied propane

Example 1 First, a composite metal oxide was synthesized in the following manner so that the charged metal element ratio was Mo ₁ V _0.30 Te _0.20 Nb _0.12 . 6. In about 40 ml of warm water.
1 g of ammonium paramolybdate, 1.4 g of ammonium metavanadate, and 1.8 g of telluric acid were dissolved to prepare a red uniform aqueous solution. Niobium pentoxide sol (Nb ₂ O ₅ 10 wt%, manufactured by Taki Kagaku Co., Ltd.) was weighed to this solution kept at 70 ° C. so that Nb became 4.8 mmol.
Average particle diameter 5 μm, oxalic acid 2.453 wt%, pH
4.2, total amount of NH ₃ and NH ⁴⁺ of about 0.64 wt%) was added and stirred to obtain a substantially uniform slurry. Here, “substantially uniform” refers to a stable solution or colloidal solution in which no precipitate is generated from the slurry even without stirring, or a slurry state. Further, an 8% aqueous solution of hydrazine hydrate was weighed such that the amount of hydrazine hydrate was 5.4 mmol. After the dropping, the color of the slurry immediately changed to black-blue, which confirmed that the oxidation-reduction reaction of each metal had progressed. After confirming that the generation of bubbles was completed after about 15 minutes, the black-blue slurry was immediately dried by repeating the following operation to obtain a black-blue dried solid. The slurry was sprayed on a commercially available hot plate heated to about 170 ° C. by a commercially available spray, dried, and immediately removed from the hot plate. The time required for the slurry sprayed on the hot plate in one spray to dry was about 10 seconds or less. A catalyst was obtained from the dried solid by the following operation. Approximately 2 g of the dried solid was packed in a 20 mm inner diameter quartz tubular firing tube,
60 hours from room temperature in a nitrogen stream of 100 ml / min.
The temperature was raised to 0 ° C., calcined at 600 ° C. (1.0 atm) for 2 hours, and then cooled in a nitrogen stream to 200 ° C. or less. to obtain a ₁ V _0.30 Te _0.17 Nb _0.12 composite metal oxide O _n black is. The weight loss due to the high temperature treatment was about 15%, and during this high temperature treatment, generation of a large amount of explosive gas such as CO was not confirmed by a gas chromatography mass spectrometer or the like. 550 m of the obtained composite metal oxide
g in a fixed bed flow reactor having a 6 mm inner diameter tubular shape, a reaction temperature of 420 ° C., a WWH of 0.104 h ⁻¹ , and a space velocity of SV.
Propane / ammonia / air = 1 / at about 900h ^-1
A gas was supplied at a molar ratio of 1.2 / 15 to perform a gas phase catalytic oxidation reaction. The results are shown in Table 1.

<Example 2> In Example 1, hydrazine hydrate 8 was used.
Hydrazine sulfate 5.4 mm
except for changing the ol hydrazine sulfate aqueous solution prepared by dissolving in warm water at 70 ° C. in the same manner as in Example 1 energy dispersive fluorescent empirical formula determined by X-ray analysis apparatus Mo ₁ V
Was obtained _0.30 Te _0.17 Nb _0.12 composite metal oxide black is O _n. 550 mg of the obtained composite metal oxide was used for an inner diameter of 6 m.
m into a fixed bed flow reactor having a tubular shape and a reaction temperature of 420
A gas was supplied at a molar ratio of propane / ammonia / air = 1 / 1.2 / 15 at a temperature of ℃, a WWH of 0.104 h ^-1 and a space velocity SV of about 900 h ^-1 to perform a gas phase catalytic oxidation reaction. The results are shown in Table 1.

Example 3 Hydrazine hydrate 8 in Example 1
% Aqueous solution of hydroxylamine sulfate 1
An empirical formula determined by an energy dispersive X-ray fluorescence analyzer was Mo ₁ V _0.30 Te in the same manner as in Example 1 except that an aqueous solution of hydroxylamine sulfate prepared by dissolving 0.7 mmol in hot water at 70 ° C. was used. was obtained _0.17 Nb _0.12 composite metal oxide black is O _n. Obtained composite metal oxide 5
50 mg was charged into a 6 mm inner diameter tubular fixed bed flow reactor, and the reaction temperature was 420 ° C., WWH was 0.104 h ⁻¹ , and space velocity SV was about 900 h ⁻¹ , and propane / ammonia / air = 1 / 1.2 / 15. A gas was supplied at a molar ratio to perform a gas phase catalytic oxidation reaction. The results are shown in Table 1.

<Example 4> In Example 1, hydrazine hydrate 8 was used.
Hydrazine hydrochloride 5.4 mm
except for changing the ol hydrazine hydrochloride aqueous solution prepared by dissolving in warm water at 70 ° C. in the same manner as in Example 1 energy dispersive fluorescent empirical formula determined by X-ray analysis apparatus Mo ₁ V
Was obtained _0.30 Te _0.17 Nb _0.12 composite metal oxide black is O _n. 550 mg of the obtained composite metal oxide was used for an inner diameter of 6 m.
m into a fixed bed flow reactor having a tubular shape and a reaction temperature of 420
A gas was supplied at a molar ratio of propane / ammonia / air = 1 / 1.2 / 15 at a temperature of ℃, a WWH of 0.104 h ^-1 and a space velocity SV of about 900 h ^-1 to perform a gas phase catalytic oxidation reaction. The results are shown in Table 1.

The composite metal oxide catalysts obtained in Examples 1 to 4 were composite metal oxides having substantially the same composition, and all were calcined at 600 ° C. (1.0 atm) for 2 hours in a nitrogen stream. Table 1 shows that Example 2 was obtained.
The performance of the catalyst obtained in Example 1 is superior to the performance of the catalyst obtained in Examples 1, 3, and 4. The reducing substance added to efficiently prepare the catalyst having excellent performance is sulfuric acid. It can be seen that hydrazines are preferred over hydroxylamines when compared with salts. In addition, it can be seen that hydrazine hydrate is more preferable than hydroxylamine sulfate, and hydrazine sulfate is more preferable.

Comparative Example 1 First, a composite metal oxide was synthesized in the following manner so that the charged metal element ratio was Mo ₁ V _0.3 Te _0.20 Nb _0.12 . 6. In about 40 ml of warm water.
1 g of ammonium paramolybdate, 1.4 g of ammonium metavanadate, and 1.8 g of telluric acid were dissolved to prepare a red uniform aqueous solution. Dissolve 11.6 mmol of oxalic acid dihydrate in about 8 ml of hot water at 70 ° C.
The solution prepared by adding the same niobium pentoxide sol used in Example 1, which was weighed so as to be 4.8 mmol, was added to the above-mentioned homogeneous aqueous solution kept at 70 ° C., and stirred to obtain a substantially uniform solution. A good slurry was obtained. Here, “substantially uniform” refers to a stable solution or colloidal solution in which no precipitate is generated from the slurry even without stirring, or a slurry state. Here, the color of the slurry remains orange, and no oxidation-reduction reaction of each metal has occurred. The orange slurry was immediately dried by repeating the following operation to obtain a brown dry solid. About 170 ° C
The slurry was sprayed on a commercially available hot plate heated by the above method using a commercially available spray, dried, and immediately removed from the hot plate. The time required for the slurry sprayed on the hot plate in one spray to dry was about 10 seconds or less. A catalyst was obtained from the dried solid by the following operation. About 2 g of this dry solid is
mm in a quartz tubular firing tube, heated from room temperature to 600 ° C. in about 1 hour in a nitrogen stream at 100 ml / min.
After baking at 0 ° C. (1.0 atm) for 2 hours, it is allowed to cool in a nitrogen stream to 200 ° C. or less, and the energy dispersive fluorescent X
The empirical formula determined by the _X- ray analyzer is Mo ₁ V _0.30 Te _0.16
To obtain a composite metal oxide of the black is Nb _0.12 O _n. The weight loss due to the high-temperature treatment was about 25%, and during this high-temperature treatment, generation of a large amount of explosive gas such as CO was confirmed by gas chromatography and a mass spectrometer. 550 mg of the obtained composite metal oxide was filled in a fixed bed flow reactor having a 6 mm inner diameter tubular shape, and the reaction temperature was 420 ° C and the WWH0.
104 h ^-1 , space velocity SV about 900 h ^-1 and propane /
A gas was supplied at a molar ratio of ammonia / air = 1 / 1.2 / 15 to perform a gas phase catalytic oxidation reaction. The results are shown in Table 1.

<Comparative Example 2> The charged metal element ratio was Mo ₁
A composite metal oxide was synthesized in the following manner so that V _0.3 Te _0.20 Nb _0.12 was obtained. Dissolve 7.1 g of ammonium paramolybdate, 1.4 g of ammonium metavanadate, 1.8 g of telluric acid in about 40 ml of warm water,
A homogeneous aqueous solution was prepared. Nb is added to this 70 ° C homogeneous solution.
4.8 mmol was added, and the same niobium pentoxide sol used in Example 1 was added thereto and stirred to obtain a substantially uniform slurry. Here, “substantially uniform” refers to a stable solution or colloidal solution in which no precipitate is generated from the slurry even without stirring, or a slurry state. Here, the color of the slurry remains orange, and no oxidation-reduction reaction of each metal has occurred. The orange slurry was immediately dried by repeating the following operation to obtain a brown dry solid. The slurry was sprayed on a commercially available hot plate heated to about 170 ° C. by a commercially available spray, dried, and immediately removed from the hot plate.
The time required for the slurry sprayed on the hot plate in one spray to dry was about 10 seconds or less.
A catalyst was obtained from the dried solid by the following operation. About 2 g of the dried solid was packed in a quartz tubular firing tube having an inner diameter of 20 mm, and the temperature was raised from room temperature to 600 ° C. in about 1 hour in a nitrogen stream at 100 ml / min.
After calcination for 2 hours at atm), allowed to cool in a nitrogen stream up to 200 ° C. or less, energy dispersive fluorescent empirical formula determined by X-ray analysis apparatus _{Mo 1 V 0.30 Te 0.17 Nb 0.12} O n
Was obtained. 550 mg of the obtained composite metal oxide was charged into a 6 mm-diameter tubular fixed-bed flow reactor, and the reaction temperature was 420 ° C. and the WWH was 0.104.
h ^-1, in the space velocity SV of about 900h ^-1 supplying a gas in a molar ratio of propane / ammonia / air = 1 / 1.2 / 15, it was vapor-phase catalytic oxidation reaction. The results are shown in Table 1.

Comparative Example 3 The charged metal element ratio was Mo ₁
A composite metal oxide was synthesized in the following manner so that V _0.3 Te _0.23 Nb _0.12 was obtained. Dissolve 10.6 g ammonium paramolybdate, 2.1 g ammonium metavanadate, 3.2 g telluric acid in 60 ml of warm water,
A red homogeneous aqueous solution was prepared. A 10.9 g aqueous solution of niobium ammonium oxalate having a niobium concentration of 0.659 mol / kg was mixed with the solution at 70 ° C. and stirred to obtain a substantially uniform slurry. Here, “substantially uniform” refers to a stable solution or colloidal solution in which no precipitate is generated from the slurry even without stirring, or a slurry state. Here the color of the slurry remains orange,
No redox reaction of each metal has occurred. The orange slurry was immediately dried by repeating the following operation to obtain a brown dry solid. The slurry was sprayed on a commercially available hot plate heated to about 170 ° C. by a commercially available spray, dried, and immediately removed from the hot plate. The time required for the slurry sprayed on the hot plate in one spray to dry was about 10 seconds or less. A catalyst was obtained from the dried solid by the following operation. About 2 g of the dried solid was packed in a quartz tubular firing tube having an inner diameter of 20 mm, and the temperature was raised from room temperature to 600 ° C. in about 1 hour in a nitrogen stream at 100 ml / min.
After calcination for 2 hours at tm), allowed to cool in a nitrogen stream up to 200 ° C. or less, empirical formula determined by energy dispersive X-ray fluorescence spectrometer is _{Mo 1 V 0.30 Te 0.17 Nb 0.12} O n black Was obtained. Generation of a large amount of COx gas was also confirmed during this high-temperature treatment. 550 mg of the obtained composite metal oxide was charged into a 6 mm-diameter tubular fixed-bed flow reactor, and the reaction temperature was 420 ° C. and the WWH was 0.104.
h ^-1, in the space velocity SV of about 900h ^-1 supplying a gas in a molar ratio of propane / ammonia / air = 1 / 1.2 / 15, it was vapor-phase catalytic oxidation reaction. The results are shown in Table 1.

Comparative Example 2 is a composite metal oxide having almost the same composition as Examples 1 to 4,
Although it was obtained by baking at 00 ° C. (1.0 tam) for 2 hours, it can be seen from Table 1 that Comparative Example 2 was dried and fired in the solution without performing any special oxidation-reduction reaction. Example 1 obtained by controlling the degree of oxidation-reduction of the system by performing an oxidation-reduction reaction in a solution using the catalyst of Example 1 and then drying and calcining.
It can be seen that the catalysts No. to No. 4 have higher acrylonitrile yields and better performance. On the other hand, Comparative Examples 1 and 3 are composite metal oxides having almost the same composition as Examples 1 to 4, and both of them are 600 ° C. (1.0 a.
Comparative Example 1 in which an oxidation-reduction reaction is performed during a high-temperature treatment despite being obtained by performing a baking treatment at tm) for 2 hours.
In Examples 3 and 3, a large amount of explosive gas is generated at the time of firing, and the operation in industrial practice becomes very complicated. However, in Examples 1 to 4, no such gas is generated particularly at the time of firing. Therefore, it is understood that the operation is easy.

Example 5 The charged metal element ratio was Mo ₁
A composite metal oxide was synthesized as follows so that V _0.25 Te _0.20 Nb _0.20 . Dissolve 7.1 g ammonium paramolybdate, 1.2 g ammonium metavanadate, 1.8 g telluric acid in about 40 ml of warm water,
A red homogeneous aqueous solution was prepared. The same niobium pentoxide sol used in Example 1 weighed so that Nb was 8.0 mmol was added to this solution kept at 70 ° C. and stirred to obtain a substantially uniform slurry. Here, “substantially uniform” refers to a stable solution or colloidal solution in which no precipitate is generated from the slurry even without stirring, or a slurry state. In addition, hydrazine hydrate is 5.
An 8% aqueous hydrazine hydrate solution weighed to 2 mmol was added dropwise. After the dropping, the color of the slurry immediately changed to black-blue, which confirmed that the oxidation-reduction reaction of each metal had progressed. After confirming that the generation of bubbles was completed after about 15 minutes, the black-blue slurry was immediately dried by repeating the following operation to obtain a black-blue dried solid. On a commercially available hot plate heated to about 170 ° C,
The slurry was sprayed with a commercially available atomizer, dried, and immediately removed from the hot plate. The time required for the slurry sprayed on the hot plate in one spray to dry was about 10 seconds or less. A catalyst was obtained from the dried solid by the following operation. About 2 of this dry solid
g into a quartz tubular firing tube having an inner diameter of 20 mm.
The temperature was raised from room temperature to 600 ° C. in about 1 hour in a nitrogen stream at ml / min, and calcined at 600 ° C. (1.0 atm) for 2 hours. The empirical formula determined by the X-ray fluorescence analyzer is Mo ₁
To obtain a composite metal oxide of the black is a _{V 0.25 Te 0.16 Nb 0.20 O n} . 550 mg of the obtained composite metal oxide was treated with an inner diameter of 6
mm into a fixed bed flow reactor having a tubular shape and a reaction temperature of 42.
0 ° C, WWH 0.104h ^-1 , Space velocity SV about 900h ^-1
And propane / ammonia / air = 1 / 1.2 / 15
, And a gas phase catalytic oxidation reaction was performed.
The results are shown in Table 1.

<Example 6> In Example 5, hydrazine hydrate 8 was used.
Hydrazine sulfate 5.2 mm
The empirical formula determined by the energy dispersive X-ray fluorescence analyzer was Mo ₁ V _{0.25 in the same} manner as in Example 3 except that an aqueous solution of hydrazine sulfate prepared by dissolving ol in 70 ° C. warm water was used. to obtain a composite metal oxide of the black is Te _0.16 Nb _0.20 O _n. Obtained composite metal oxide 550
mg into a 6 mm inner diameter tubular fixed bed flow reactor,
Reaction temperature 420 ° C, WWH 0.104h ^-1 , 1 space velocity S
V about 900h ^-1 and propane / ammonia / air = 1
A gas was supplied at a molar ratio of /1.2/15 to perform a gas phase catalytic oxidation reaction. The results are shown in Table 1.

<Comparative Example 4> The charged metal element ratio was Mo ₁
A composite metal oxide was synthesized as follows so that V _0.25 Te _0.20 Nb _0.20 . 6. In about 40 ml of 70 ° C hot water.
1 g of ammonium paramolybdate, 1.2 g of ammonium metavanadate, and 1.8 g of telluric acid were dissolved to prepare a red uniform aqueous solution. Dissolve 11.6 mmol of oxalic acid dihydrate in about 8 ml of hot water at 70 ° C.
The solution prepared by adding the same niobium pentoxide sol used in Example 1 weighed so as to be 8.0 mmol was added to the above homogeneous aqueous solution and stirred to obtain a substantially uniform slurry. . Here, “substantially uniform” refers to a stable solution or colloidal solution in which no precipitate is generated from the slurry even without stirring, or a slurry state. Here, the color of the slurry remains orange, and no oxidation-reduction reaction of each metal has occurred. The orange slurry was immediately dried by repeating the following operation to obtain a brown dry solid. The slurry was sprayed on a commercially available hot plate heated to about 170 ° C. by a commercially available spray, dried, and immediately removed from the hot plate. The time required for the slurry sprayed on the hot plate in one spray to dry was about 10 seconds or less. A catalyst was obtained from the dried solid by the following operation. About 2 g of the dried solid was placed in a 20 mm inner diameter quartz tubular firing tube, and was cooled from room temperature to about 1 g in a nitrogen stream at 100 ml / min.
Temperature rises to 600 ° C over time, 600 ° C (1.0atm)
In after calcination for 2 hours, allowed to cool in a nitrogen stream up to 200 ° C. or less, the composite empirical formula determined by energy dispersive X-ray fluorescence analyzer black is _{Mo 1 V 0.25 Te 0.15 Nb 0.20} O n A metal oxide was obtained. Obtained composite metal oxide 5
50 mg was charged into a 6 mm inner diameter tubular fixed bed flow reactor, and the reaction temperature was 420 ° C., WWH was 0.104 h ⁻¹ , and space velocity SV was about 900 h ⁻¹ , and propane / ammonia / air = 1 / 1.2 / 15. A gas was supplied at a molar ratio to perform a gas phase catalytic oxidation reaction. The results are shown in Table 1.

Comparative Example 4 is a composite metal oxide having substantially the same composition as Examples 5 and 6, and both were fired at 600 ° C. (1.0 atm) for 2 hours in a nitrogen stream. In spite of the fact that the catalyst was obtained, Table 1 shows that the oxidation-reduction reaction was performed in a solution from the catalyst of Comparative Example 4 which was dried and calcined without performing a special oxidation-reduction reaction in the solution. It can be seen that the catalysts of Example 5 and Example 6 obtained by controlling the degree of oxidation-reduction, followed by drying and calcining have higher acrylonitrile yield and better performance. Also,
It can be seen that hydrazine sulfate is preferable to hydrazine hydrate as a reducing substance added to efficiently prepare a catalyst having excellent performance.

Example 7 The charged metal element ratio was Mo ₁
A composite metal oxide was synthesized as follows so that V _0.30 Te _0.20 Nb _0.20 . In about 40 ml of warm water, 7.1 g of ammonium paramolybdate, 1.4 g of ammonium metavanadate, and 1.8 g of telluric acid were dissolved to prepare a red uniform aqueous solution. The same niobium pentoxide sol used in Example 1 weighed so that Nb was 8.0 mmol was added to this solution kept at 70 ° C. and stirred to obtain a substantially uniform slurry. Here, “substantially uniform” refers to a stable solution or colloidal solution in which no precipitate is generated from the slurry even without stirring, or a slurry state. Further, an aqueous solution of hydrazine sulfate prepared by weighing hydrazine sulfate to 5.4 mmol and dissolving it in hot water at 70 ° C. was added dropwise.
After the dropping, the color of the slurry immediately changed to black-blue, which confirmed that the oxidation-reduction reaction of each metal had progressed.
After confirming that the generation of bubbles was completed after about 15 minutes, the black-blue slurry was immediately dried by repeating the following operation to obtain a black-blue dried solid. The slurry was sprayed on a commercially available hot plate heated to about 170 ° C. by a commercially available spray, dried, and immediately removed from the hot plate. The time required for the slurry sprayed on the hot plate in one spray to dry was about 10 seconds or less. A catalyst was obtained from the dried solid by the following operation. About 2 g of the dried solid was packed in a quartz tubular firing tube having an inner diameter of 20 mm, and the temperature was raised from room temperature to 600 ° C. in about 1 hour in a nitrogen stream at 100 ml / min.
(1.0 atm) for 2 hours, then cooled in a nitrogen stream to 200 ° C. or less, and the empirical formula determined by the energy dispersive X-ray fluorescence analyzer was Mo ₁ V _0.30 Te _0.16 Nb.
To obtain a composite metal oxide of black is _0.20 O _n. 550 mg of the obtained composite metal oxide was filled in a fixed-bed flow reactor having a 6 mm inner diameter tubular shape, and the reaction temperature was 420 ° C. and the WWH was 0.1.
04h ^-1, and the space velocity SV of about 900h ^-1 supplying a gas in a molar ratio of propane / ammonia / air = 1 / 1.2 / 15, were vapor-phase catalytic oxidation reaction. The results are shown in Table 1.

<Comparative Example 5> The charged metal element ratio was Mo ₁
A composite metal oxide was synthesized as follows so that V _0.30 Te _0.20 Nb _0.20 . In about 40 ml of 70 ° C. hot water, 7.1 g of ammonium paramolybdate, 1.4 g
Was dissolved in 1.8 g of telluric acid to prepare a red uniform aqueous solution. A solution prepared by adding the same niobium pentoxide sol as used in Example 1 in which 11.6 mmol of oxalic acid dihydrate was dissolved in about 8 ml of 70 ° C warm water and Nb was weighed to be 8.0 mmol, The mixture was added to the above homogeneous aqueous solution and stirred to obtain a substantially uniform slurry. Here, “substantially uniform” refers to a stable solution or colloidal solution in which no precipitate is generated from the slurry even without stirring, or a slurry state. Here, the color of the slurry remains orange, and no oxidation-reduction reaction of each metal has occurred. The orange slurry is quickly dried by repeating the following operation,
A brown dry solid was obtained. Spray the slurry with a commercial spray on a commercial hot plate heated to about 170 ° C,
After drying, it was immediately removed from the hot plate. The time required for the slurry sprayed on the hot plate in one spray to dry was about 10 seconds or less. A catalyst was obtained from the dried solid by the following operation.
About 2 g of the dried solid was packed in a quartz tubular firing tube having an inner diameter of 20 mm, and the temperature was raised from room temperature to 600 ° C. in about 1 hour in a nitrogen stream at 100 ml / min.
After calcination for 2 hours at m), allowed to cool in a nitrogen stream up to 200 ° C. or less, empirical formula determined by energy dispersive X-ray fluorescence spectrometer is _{Mo 1 V 0.30 Te 0.16 Nb 0.20} O n black Was obtained. 550 mg of the obtained composite metal oxide was charged into a fixed-bed flow reactor, and the reaction temperature was 420 ° C., WWH was 0.104 h ⁻¹ , and the space velocity SV was about 90.
0 h ^-1 and propane / ammonia / air = 1 / 1.2
A gas was supplied at a molar ratio of / 15 to perform a gas phase catalytic oxidation reaction. The results are shown in Table 1.

Comparative Example 5 is a composite metal oxide having almost the same composition as that of Example 7, and all of them
Despite being obtained by baking at 2 ° C. (1.0 atm) for 2 hours, Table 1 shows that Comparative Example 5 was dried and calcined in the solution without performing any special oxidation-reduction reaction. The catalyst of Example 7 obtained by performing an oxidation-reduction reaction in a solution to control the degree of oxidation-reduction of the system after drying and calcining the catalyst has a higher acrylonitrile yield and excellent performance than the catalyst. You can see that there is.

Example 8 The charged metal element ratio was Mo ₁
The composite metal oxide was synthesized as follows so that V _0.30 Sb _0.17 Nb _0.09 was obtained. Using a beaker, 7.1 g of ammonium paramolybdate was dissolved in about 40 ml of warm water at 70 ° C., and 0.97 g of Sb ₂ O ₃ was added and suspended. 0.73 g of a 31% aqueous hydrogen peroxide solution was added, and the mixture was heated and reacted under a watch glass for about 2 hours. In the obtained colorless and transparent solution, 1.
An aqueous solution of ammonium metavanadate in which 4 g of ammonium metavanadate was dissolved in warm water at 70 ° C. was added to prepare an amber uniform aqueous solution. Nb was added to this solution at 3.6.
The same niobium pentoxide sol used in Example 1 weighed so as to obtain mmol was added and stirred to obtain a substantially uniform slurry. Here, “substantially uniform” refers to a stable solution or colloidal solution in which no precipitate is generated from the slurry even without stirring, or a slurry state. Further, an aqueous solution of hydrazine sulfate prepared by weighing hydrazine sulfate to 3.1 mmol and dissolving it in warm water at 70 ° C. was added dropwise. After the dropping, the color of the slurry immediately changed to dark purple, confirming that the oxidation-reduction reaction of each metal had progressed. After confirming that the generation of bubbles was completed after about 20 minutes, the black-purple slurry was immediately dried by repeating the following operation to obtain a black-purple dry solid. The slurry was sprayed on a commercially available hot plate heated to about 170 ° C. by a commercially available spray, dried, and immediately removed from the hot plate. The time required for the slurry sprayed on the hot plate in one spray to dry was about 10 seconds or less. A catalyst was obtained from the dried solid by the following operation. Approximately 2 g of the dried solid was packed in a 20 mm inner diameter quartz tubular firing tube,
In a nitrogen stream of 100 ml / min.
The temperature was raised to 5 ° C., calcined at 625 ° C. (1.0 atm) for 2 hours, and then allowed to cool in a nitrogen stream to 200 ° C. or less. to obtain a ₁ V _0.30 Sb _0.17 Nb _0.09 composite metal oxide O _n black is. 550 mg of the obtained composite metal oxide was charged into a fixed bed flow reactor having a 6 mm inner diameter tubular shape, and the reaction temperature was 420 ° C., WWH was 0.104 h ⁻¹ , and space velocity SV was about 9
Propane / ammonia / air = 1 / 1.2 / 15 with 00h ^-1
, And a gas phase catalytic oxidation reaction was performed.
The results are shown in Table 1.

<Comparative Example 6> The charged metal element ratio was Mo.₁ 
V_0.30Sb_0.17Nb_0.09Composite metal oxidation
The product was synthesized as follows. 70 ° C temperature in a beaker
7.1 g of ammonium paramolybdate in about 40 ml of water
And dissolve Sb_TwoO_Three Add 0.97g and suspend
Was. 0.73 g of a 31% aqueous hydrogen peroxide solution was added for about 2 hours
During the reaction, the reaction was performed under a watch glass. The resulting clear, colorless solution
And 1.4 g of ammonium metavanadate at 70 ° C.
Aqueous solution of ammonium metavanadate dissolved in warm water
Was added to prepare an amber homogeneous aqueous solution. 70 ° C hot water
Approximately 8 ml of oxalic acid dihydrate (5.6 mmol) was dissolved in
For use in Example 1 where b was weighed to be 3.6 mmol
Solution prepared by adding the same Nb pentoxide sol
Is added to the above homogeneous aqueous solution kept at 40 ° C. and stirred.
Thus, a substantially uniform slurry was obtained. Here, substantially equal
One means that sediment will form from the slurry without stirring.
No stable solution or colloid solution, or slurry
-State. Here the color of the slurry is yellow-orange
The color remains, and the redox reaction of each metal has not occurred.
No. Repeat the following operation for the yellow-orange slurry immediately.
To give a brown dry solid. About 170
Place the slurry on a commercially available hot plate heated to
Spray with sales spray, dry immediately and hot plate
Removed from Spray on hot plate with one spray
It takes about 10 seconds for the slurry to dry
It was below. Perform the following operations from a dry solid
Thus, a catalyst was obtained. About 2 g of this dried solid is
Packed in a 0 mm quartz tubular firing tube,
In a stream of air, the temperature was raised from room temperature to 625 ° C in about 1 hour,
After firing for 2 hours at 25 ° C. (1.0 atm), 200 ° C.
Allow to cool in a nitrogen stream to
The empirical formula determined by the X-ray analyzer is Mo₁ V_0.30Sb_0.
17Nb_0.09A black composite metal oxide, On, was obtained. Profit
Of 550 mg of the obtained composite metal oxide into a tubular solid having an inner diameter of 6 mm.
Packed in a fixed bed flow reactor, reaction temperature 420 ° C, WWH
0.104h^-1, Space velocity SV about 900h^-1And prop
Gas / ammonia / air = 1 / 1.2 / 15 molar ratio
And a gas phase catalytic oxidation reaction was performed. Table 1 shows the results.
Shown in

Comparative Example 6 is a composite metal oxide having substantially the same composition as that of Example 8, and all of them are 625 under a nitrogen stream.
Table 1 shows that the catalyst of Comparative Example 6 was dried and calcined without performing any special reduction treatment in the solution, although it was obtained by calcining at 1.0 ° C. (1.0 atm) for 2 hours. Thus, the catalyst of Example 8 obtained by performing a reduction treatment in a solution to control the degree of oxidation-reduction of the system and then drying and calcining has a higher acrylonitrile yield and higher performance. I understand.

<Example 9> The charged metal element ratio was Mo.₁ 
V_0.25Te_0.20Nb_0.20SiO _Two About
A composite metal oxide containing 10 wt% was synthesized as follows.
Add 105.9 g of paramolybdate to 400 ml of warm water.
Ammonium salt, 17.5 g of ammonium metavanadate
Dissolve 27.6 g of telluric acid, red uniform water
A solution was prepared. 20 wt% silica sol 7 was added to this solution.
5 g was added and Nb was further adjusted to 120 mmol.
Niobium pentoxide sol used in Example 1
Was added and stirred to obtain a substantially uniform slurry. here
Is substantially uniform means that the slurry
A stable solution or a colloid solution that does not produce sediment,
Or it means that it is in a slurry state. Keep at 70 ° C
80 mmol of hydrazine sulfate is added to this slurry solution.
Was prepared by dissolving in warm water at 70 ° C.
An aqueous hydrazine sulfate solution was added. After dropping the slurry
Since the color quickly changed to black-blue, redox of each metal
It was confirmed that the original reaction had progressed. After about 20 minutes bubbles
Confirm that the baking is finished, and immediately add the black-blue slurry.
Dry at about 200 ° C using a centrifugal spray dryer
Was removed to obtain a black-blue dry solid. Next from dry solid
A catalyst was obtained through the above operations. This dried solid
About 2 g of the body is placed in a 20 mm inner diameter quartz tubular firing tube.
About 1 hour from room temperature in a nitrogen stream of 100 ml / min.
Raise temperature to 600 ° C, 2 hours at 600 ° C (1.0atm)
After firing, allow to cool in a nitrogen stream to 200 ° C or less.
The energy determined by the energy dispersive X-ray fluorescence analyzer.
The empirical formula is Mo₁ V_0.25Te_0.16Nb_0.20O_n And Si
O_Two Was obtained in about 10 wt%.
550 mg of the obtained composite metal oxide was introduced into a 6 mm inner diameter tubular
Packed in a fixed bed flow type reactor, reaction temperature 420 ° C, WW
H0.104h^-1, Space velocity SV about 600h^-1And professional
Pan / ammonia / air = 1 / 1.2 / 15 molar ratio
Gas was supplied to perform a gas phase catalytic oxidation reaction. Table-Results
It is shown in FIG.

<Comparative Example 7> The charged metal element ratio was Mo.₁ 
V_0.25Te_0.20Nb_0.20SiO _Two About
A composite metal oxide containing 10 wt% was synthesized as follows.
Approximately 530 ml of hot water at 60 ° C and 141.2 g of paramorib
Ammonium denate, 23.4 g of metavanadate
Ammonium salt, dissolve 36.7 g of telluric acid
Prepare a homogeneous aqueous solution, and further add 20 wt% silica sol
100 g were added. Oxalic acid in about 100 ml of 70 ° C hot water
Dissolve 232 mmol of dihydrate and add 160 mmol of Nb
The same pentaacid used in Example 1 weighed to 1
Solution prepared by adding niobium sol is cooled to 40 ° C
After that, add to the above solution and stir to obtain a substantially uniform slurry.
I got it. Here, “substantially uniform” means that stirring is not performed.
Or a stable solution that does not produce sediment from the slurry,
Refers to a colloidal solution or a slurry state.
Here, the color of the slurry remains orange and the acid of each metal
No redox reaction has occurred. This orange slurry quickly
Dry at about 200 ° C using a crab centrifugal spray dryer
The water was removed to give a dry brown solid. Dry solid to next
A catalyst was obtained by the following procedure. This dry
About 2 g of the solid is placed in a 20 mm inner diameter quartz tubular firing tube.
About 1 hour from room temperature in a nitrogen stream of 100 ml / min.
Raise temperature to 600 ° C, 2 hours at 600 ° C (1.0atm)
After firing, allow to cool in a nitrogen stream to 200 ° C or less.
The energy determined by the energy dispersive X-ray fluorescence analyzer.
The empirical formula is Mo ₁ V_0.25Te_0.15Nb_0.20O_n With SiO_Two To
A black composite metal oxide containing about 10 wt% was obtained. Obtained
550 mg of mixed metal oxide was fixed to a tubular fixed bed with an inner diameter of 6 mm.
The reactor was charged into a flow-through reactor, and the reaction temperature was 420 ° C. and the WWH
104h^-1, Space velocity SV about 600h^-1And propane /
Ammonia / air = gas at a molar ratio of 1 / 1.2 / 15
The mixture was supplied to perform a gas phase catalytic oxidation reaction. The results are shown in Table 1.
You.

Comparative Example 7 is a composite metal oxide having almost the same composition as that of Example 9, and all of them
Despite being obtained by baking at 2 ° C. (1.0 atm) for 2 hours, Table 1 shows that Comparative Example 7 was dried and calcined in the solution without performing any special oxidation-reduction reaction. The catalyst of Example 9 obtained by performing an oxidation-reduction reaction in a solution to control the degree of oxidation-reduction of the system and drying and calcining the catalyst has a higher acrylonitrile yield and excellent performance than the catalyst. You can see that there is. Also in Comparative Examples 4 to 7 described above, generation of explosive gas such as CO during firing was confirmed as in Comparative Examples 1 to 3.

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[Table 1]

Example 10 120 mg of the black composite metal oxide obtained in Example 2 was mixed with inert quartz grains, and the mixture was charged into a 6 mm-diameter tubular fixed-bed flow reactor. WWH 1.85h ^-1 , space velocity SV about 1
600 h ^-1 and propane / ammonia / oxygen / nitrogen =
Gas is supplied at a molar ratio of 1 / 0.3 / 1.5 / 1.2,
A gas phase catalytic oxidation reaction was performed. Table 2 shows the results.

<Comparative Example 8> 120 mg of the black composite metal oxide obtained in Comparative Example 1 was mixed with inert quartz grains and charged into a 6 mm-diameter tubular fixed-bed flow reactor. WWH 1.85h ^-1 , space velocity SV about 16
00h ^-1 and propane / ammonia / oxygen / nitrogen = 1
A gas was supplied at a molar ratio of /0.3/1.5/1.2 to perform a gas phase catalytic oxidation reaction. Table 2 shows the results.

<Comparative Example 9> 120 mg of the black composite metal oxide obtained in Comparative Example 3 was mixed with inert quartz grains and charged into a 6 mm-diameter tubular fixed-bed flow reactor. WWH 1.85h ^-1 , space velocity SV about 16
00h ^-1 and propane / ammonia / oxygen / nitrogen = 1
A gas was supplied at a molar ratio of /0.3/1.5/1.2 to perform a gas phase catalytic oxidation reaction. Table 2 shows the results.

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[Table 2]

Comparative Examples 8 and 9 are composite metal oxides having almost the same composition as Example 10, and both were obtained by calcination treatment at 600 ° C. (1.0 atm) for 2 hours in a nitrogen stream. Table 2 shows that the catalysts of Comparative Examples 8 and 9, which were dried and calcined without performing any special oxidation-reduction reaction in the solution, were subjected to oxidation-reduction reaction in the solution, The catalyst of Example 10 obtained by controlling the degree of oxidation-reduction and then drying and calcining has a higher selectivity for the total of acrylonitrile and acrylic acid obtained at almost the same propane conversion, and a higher acrylonitrile selectivity. And even
It can be seen that the selectivity of acrylonitrile from ammonia is high and the performance is excellent. In comparison of the propane conversion rate per specific surface area, Table 2 shows that the catalysts of Comparative Examples 8 and 9, which were dried and calcined without performing a special oxidation-reduction reaction in the solution, showed a redox reaction in the solution. And the catalyst of Example 10 obtained by drying and calcining after controlling the degree of oxidation-reduction of the system has a higher propane conversion rate per specific surface area and is superior in propane conversion activity per specific surface area. You can see that.

Example 11 275 mg of the black composite metal oxide obtained in Example 2 was charged into a 6 mm-diameter tubular fixed-bed flow reactor, and the reaction temperature was 420 ° C. and the WWH was 0.3.
59 h ^-1 , space velocity SV about 1800 h ^-1 and propane /
Gas was supplied at a molar ratio of oxygen / water / nitrogen = 1 / 1.8 / 2.2 / 5.0 to perform a gas phase catalytic oxidation reaction. The results are shown in Table-3.

Comparative Example 10 275 mg of the black composite metal oxide obtained in Comparative Example 1 was charged into a 6 mm-diameter tubular fixed-bed flow reactor, and the reaction temperature was 420 ° C. and WWH 0.3.
59 h ^-1 , space velocity SV about 1800 h ^-1 and propane /
Gas was supplied at a molar ratio of oxygen / water / nitrogen = 1 / 1.8 / 2.2 / 5.0 to perform a gas phase catalytic oxidation reaction. The results are shown in Table-3.

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[Table 3]

Comparative Example 10 is a composite metal oxide having substantially the same composition as that of Example 11, and all of them were prepared under nitrogen flow.
Table 3 shows that Comparative Example 10 was dried and fired in the solution without performing a special oxidation-reduction reaction, despite being obtained by firing at 00 ° C. (1.0 atm) for 2 hours. The catalyst of Example 11 obtained by performing an oxidation-reduction reaction in a solution to control the degree of oxidation-reduction of the system, and then drying and calcining was higher in acrylic acid yield and selectivity than Is excellent.

The following example is an example in which a starting compound is subjected to an oxidation-reduction reaction. <Example 12> The charged metal element ratio was Mo ₁ V _0.30 Sb.
_The composite oxide was synthesized in the following manner so as to obtain _0.17 Nb _0.09 . Using a beaker, dissolve 7.1 g of ammonium paramolybdate in about 40 ml of 70 ° C. hot water,
0.97 g of Sb ₂ O ₃ was added and suspended. 0.73 g of a 31% aqueous hydrogen peroxide solution was added, and the mixture was heated and reacted under a watch glass for about 2 hours. A solution in which 0.94 g of ammonium metavanadate was dissolved in 30 ml of hot water at 70 ° C. was added to the obtained colorless and transparent solution to prepare an amber homogeneous solution. A solution prepared by dissolving 2.7 mmol of oxalic acid dihydrate in about 5 ml of 70 ° C. warm water and adding the same niobium pentoxide sol used in Example 1 weighed so that Nb becomes 3.6 mmol was prepared. , Added to the above homogeneous aqueous solution kept at 40 ° C.,
Stirring resulted in a substantially uniform slurry. Here, “substantially uniform” refers to a stable solution or colloidal solution in which no precipitate is generated from the slurry even without stirring, or a slurry state. Further, a solution in which 4 mmol of vanadyl sulfate was dissolved in 30 ml of warm water was added dropwise to the slurry. After the dropwise addition, the slurry immediately turned black-purple, which confirmed that the oxidation-reduction reaction of each metal had progressed. After stirring at about 70 ° C. for about 20 minutes, the black-purple slurry was immediately dried by repeating the following operation to obtain a black-purple dry solid. The slurry was sprayed on a commercially available hot plate heated to about 170 ° C. by a commercially available spray, dried, and immediately removed from the hot plate. The time required for the slurry sprayed on the hot plate in one spray to dry was about 10 seconds or less. A catalyst was obtained from the dried solid by the following operation. Approximately 2 g of this dry solid is
And heated from room temperature to 625 ° C. in about 1 hour in a nitrogen stream at 100 ml / min.
(1.0 atm) for 2 hours, then cooled in a nitrogen stream to 200 ° C. or lower, and the empirical formula determined by the energy dispersive X-ray fluorescence analyzer was Mo ₁ V _0.30 Sb _0.17 Nb.
To obtain a composite oxide of black is _0.09 O _n. 550 mg of the obtained composite oxide was packed in a tubular fixed-bed flow reactor having an inner diameter of 6 mm, and the reaction temperature was 430 ° C. and the WWH was 0.104.
h ^-1, in the space velocity SV of about 900h ^-1 supplying a gas in a molar ratio of propane / ammonia / air = 1 / 1.2 / 15, it was vapor-phase catalytic oxidation reaction. The results are shown in Table-4.

<Comparative Example 11> In Example 12, a vanadium source was used.
Do not use vanadyl sulfate as a raw material, use instead
Increase the amount of ammonium metavanadate to 1.4 g
Energy dispersion type in the same manner as in Example 12 except that
The empirical formula determined by the fluorescent X-ray analyzer is Mo ₁V_0.30S
b_0.17Nb_0.09O_nWas obtained. Dry
The color of the slurry before drying remains yellow-orange and
No metal redox reaction has occurred. The resulting complex acid
550 mg of a compound having a 6 mm inner diameter tubular fixed bed flow reactor
At a reaction temperature of 430 ° C. and a WWH of 0.104 h.^-1,
Space velocity SV about 900h^-1And propane / ammonia
/ Air = gas supply at a molar ratio of 1 / 1.2 / 15, gas phase contact acid
The reaction was carried out. The results are shown in Table-4.

Comparative Example 11 is a composite oxide having almost the same composition as that of Example 12, and all of them are 625 under a nitrogen stream.
Table 4 shows that a part of the vanadium raw material was converted to vanadyl sulfate to control the degree of oxidation-reduction of the system in the solution, despite the fact that it was obtained by baking at 2 ° C. (1.0 atm) for 2 hours. It can be seen that the catalyst of Example 12 obtained by drying and calcining after that has a higher acrylonitrile yield and better performance.

Example 13 The charged metal element ratio was Mo.₁ V_0.30Te_0.20Nb_0.12When
Thus, a composite metal oxide was synthesized as follows.
7.1 g of ammonium paramolybdate in about 40 ml of warm water
Sodium salt, 1.4 g ammonium metavanadate,
Dissolve 1.8 g of telluric acid and prepare a red uniform aqueous solution.
Made. 4.8 mm of Nb was added to this solution kept at 70 ° C.
The same five as used in Example 1 weighed to be ol
Add niobium oxide sol and stir to obtain a substantially uniform slurry.
I got it. Here, “substantially uniform” means that stirring is not performed.
Or a stable solution that does not produce sediment from the slurry,
Refers to a colloidal solution or a slurry state.
To this slurry, 5.25 g of a 10 wt% sulfuric acid aqueous solution was added.
It was added dropwise. Add acetol (hydrogen) to the slurry.
(Roxyacetone) 0.42 g was added dropwise. After dripping
The color of the rally quickly changed to black and blue, so each metal
It was confirmed that the oxidation-reduction reaction proceeded. slurry
Was stirred under a watch glass at about 70 ° C. for about 45 minutes. So
After that, immediately perform the following operations on the black-blue slurry.
Drying by inversion gave a black-blue dry solid. About 1
Place the slurry on a commercially available hot plate heated to 70 ° C.
Is sprayed with a commercially available atomizer, and immediately after drying,
Removed from the sheet. Blow on hot plate with one spray
The time required for the ground slurry to dry is about 1
It was 0 seconds or less. The following operations are performed from a dry solid
Thus, a catalyst was obtained. About 2 g of this dry solid
Packed in a 20 mm diameter quartz tubular firing tube, 100 ml / min
Temperature from room temperature to 600 ℃ in about 1 hour
And calcined at 600 ° C. (1.0 atm) for 2 hours.
Cool in a nitrogen stream to 00 ° C or less to disperse energy
The empirical formula determined by the X-ray fluorescence X-ray analyzer is Mo₁ V_0.30
Te_0.16Nb _0.12O_n Black composite metal oxide
Was. 550 mg of the obtained composite metal oxide was placed in a 6 mm inner diameter tube.
Into a fixed-bed flow reactor having a reaction temperature of 420 ° C.
WWH 0.104h^-1, Space velocity SV about 900h^-1To
Propane / ammonia / air = 1 / 1.2 / 15 mol
Gas was supplied at a ratio to perform a gas phase catalytic oxidation reaction. The result
It is shown in Table-4.

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[Table 4]

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By producing a composite oxide catalyst using the method of the present invention, no explosive gas is generated as compared with the conventional method, so that the operation is easy and the process is simpler. A catalyst can be produced efficiently. In addition, the obtained catalyst shows good performance in terms of the yield, selectivity, and production rate of the target product in the gas phase oxidation reaction of alkanes, and thus has great industrial merit.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 23/68 B01J 23/89 Z 23/88 27/051 Z 23/89 27/057 Z 27/051 27 / 24 Z 27/057 37/08 27/24 37/16 37/08 C07C 51/215 37/16 57/05 C07C 51/215 253/24 57/05 255/08 253/24 C07B 61/00 300 255 / 08 B01J 23/64 103Z // C07B 61/00 300 104Z

Claims (14)

[Claims] 1. A method according to claim 1, wherein a compound compound of at least Mo and V is mixed in a liquid medium under a pressure of 5 atm or less.
After a redox reaction at a temperature below the boiling point of the liquid medium,
A method for producing a composite oxide, comprising removing and drying a liquid medium. 2. The method for producing a composite oxide according to claim 1, wherein the composite oxide is represented by the following general formula [1]. Embedded image (Where X is Ti, Zr, Nb, Ta, Cr, W, M
n, Fe, Ru, Co, Rh, Ir, Ni, Pd, P
t, Cu, Ag, Zn, In, Sn, Pb, Bi, G
e, one or more elements selected from S and Ce, and 0.01 ≦ a <1.0, 0 ≦ b ≦ α, 0 ≦ x <1.
0, 0.01 ≦ α / (1 + a + x) ≦ 0.50, 0 ≦ y
≤ (1 + a + α + x), n is a number determined by the oxidation state of another element. ) 3. Water is used as a liquid medium, a water-soluble Mo compound is used as a Mo raw material compound, a water-soluble V compound is used as a V raw material compound, a water-soluble Te compound is used as a Te raw material compound,
2. A water-soluble Sb compound is used as the raw material compound b.
Or the manufacturing method of the composite oxide as described in 2. 4. The V raw material compound has an average valence m of V of 4 ≦ m.
The method for producing a composite oxide according to any one of claims 1 to 3, wherein the compound is selected from V compounds that satisfy ≤5. 5. The method for producing a composite oxide according to claim 1, wherein a substance having a reducing property is present in the liquid medium. 6. The method for producing a composite oxide according to claim 4, wherein the reducing substance is at least one selected from inorganic hydrazines, inorganic amines, aldehydes, alcohols, and carboxylic acids. 7. A substance having a reducing property in a medium, Mo,
The method for producing a composite oxide according to claim 4, wherein the compound is present at a ratio of 0.001 mol ratio or more and 20 mol ratio or less based on the total number of moles of V, Te, Sb, and X. 8. A method for producing a composite oxide, comprising firing the composite oxide of the general formula [1] obtained by the method according to claim 1 at a temperature of 350 ° C. or higher. . 9. The method according to claim 8, wherein the firing is performed in an atmosphere having an oxygen concentration lower than that of air. 10. A composite oxide catalyst obtained by the production method according to claim 1. 11. A method for producing a nitrile by ammoxidizing an alkane in the presence of a catalyst, wherein the composite oxide catalyst according to claim 10 is used as a catalyst. 12. A method for producing an α, β unsaturated carboxylic acid by subjecting an alkane to gas-phase oxidation in the presence of a catalyst, wherein the composite oxide catalyst according to claim 10 is used as a catalyst. , A process for producing β-unsaturated carboxylic acid. 13. The composite oxide catalyst according to claim 10, wherein
In the presence of ammonia and oxygen, the alkane undergoes a gas phase reaction,
In the method for producing a nitrile and an α, β-unsaturated carboxylic acid, by controlling a ratio of ammonia, an alkane, and oxygen supplied to a reactor, controlling a ratio of a generated nitrile and an α, β-unsaturated carboxylic acid. A process for producing a nitrile and an α, β unsaturated carboxylic acid, characterized in that: 14. The method according to claim 11, wherein the alkane is propane or isobutane.