JP2000143244A - Production of multiple metal oxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a catalyst excellent in characteristics such as selectivity and activity in a condition of a low temp. by hydrothermally treating a raw material mixture containing Mo, V, Te, Sb in a specific temp. range. SOLUTION: This water based mixture containing each raw material of Mo, V, Te, Sb is hydrothermally treated at 100-350 deg.C to obtain a multiple metal oxide expressed by Mo1.0VaTebSbα-bXx(NH4)yOz. In the formula, X represents >=1 kinds of elements selected from Ti, Zr, Nb, Ta, Cr, W, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Zn, In, Sn, Pb, Bi and Ce, 0.01<=a<=1.0, 0<=b<=α, 0<=x<=1.0, 0.01<=α/(1+a+x)<=0.05, 0<=y<=(1+a+x) and (n) is fixed by the oxidizing state of other elements. Each raw material exists in the dispersed or dissolved state in water before the reaction and is necessarily heated in the reaction vessel. At least a part of the raw materials is preferably soluble in water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A composite metal oxide catalyst containing Mo, V, Te, O or Mo, V, Sb, O as an essential component is known as a gas-phase selective oxidation catalyst for lower saturated hydrocarbons. For example, as a catalyst effective for producing acrylonitrile by an ammoxidation reaction of propane, JP-A-5-208136 discloses that Mo,
As a catalyst containing V, Te, and O as essential components, Japanese Patent Application Laid-Open No. 9-157241 discloses a catalyst containing Mo, V, Sb, and O as essential components.

[0003] As catalysts effective for the production of acrylic acid by a gas phase oxidation reaction of propane, Mo, V are disclosed in JP-A-6-279351, JP-A-7-10801 and JP-A-8-196626. , A catalyst containing Te and O as essential components is disclosed in JP-A-9-31
No. 6023, JP-A-10-045664, JP-A-10-118491
JP-A-10-120617 and JP-A-10-137585 disclose catalysts containing Mo, V, Sb, and O as essential components. Further, as an effective catalyst for the production of ethylene by gas phase oxidation of ethane, JP-A-7-53414 discloses M
A catalyst containing o, V, Te, and O as essential components is disclosed in JP-A-10-175885.
In this publication, a catalyst containing Mo, V, Sb, and O as essential components is disclosed.

[0004]

According to these publications, it is necessary to calcine at a high temperature of 500 ° C. or more in order to prepare a composite metal oxide catalyst having sufficient performance.
Further, catalysts prepared by these methods have sufficiently high catalytic performance, but are required to have even higher performance for industrial use. The present invention provides a method for efficiently synthesizing a desired catalyst at a low temperature at a low energy cost in a composite metal oxide catalyst system containing Mo, V, and Te and / or Sb, and selecting and producing a target product. An object is to obtain a catalyst having good performance such as speed.

[0005]

Means for Solving the Problems The inventors of the present invention have studied the method of synthesizing Mo, V, and the contained composite metal oxide while taking the above-mentioned problems into consideration. It has been found that a composite metal oxide containing Mo, V, and Te and / or Sb can be synthesized under lower temperature conditions as compared with the conventional method, and further, the composite metal oxide prepared by the production method of the present invention. Was found to have very high activity as a catalyst, and reached the present invention.

That is, the gist of the present invention is to provide a method for producing a composite metal oxide represented by the following general formula [1], wherein an aqueous mixture containing a raw material compound is subjected to hydrothermal treatment at 100 to 350 ° C. Exist.

[0007]

## STR2 ## _{Mo 1.0 V a Te b Sbα -b} X x (NH 4) y O n [1]

(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 and Ce, 0.01 ≦ a <1.0, 0 ≦ b ≦ α, 0 ≦ x <1.0, 0.01 ≦ α
/(1+a+x)≦0.50, 0 ≦ y ≦ (1 + a + x), and n is a number determined by the oxidation state of another element. )

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, each raw material for producing the composite metal oxide is present in a state of being dispersed or dissolved in water before the reaction,
It is necessary to heat in a pressure vessel. In order to produce the desired composite oxide with good yield, it is preferable that at least a part of the raw material is soluble in water.

The starting compounds used in the present invention include:
The Mo raw material is usually made of M which is at least partially soluble in water.
o, preferably a water-soluble compound containing Mo, more preferably a water-soluble compound containing Te and Mo, or a water-soluble compound containing Sb and Mo, particularly preferably Te and Mo. Or a water-soluble compound having a heteropolyanion containing Sb and Mo, most preferably a water-soluble compound having an Anderson-type Te-Mo heteropolyanion or Anderson-type Sb-Mo.
It is a water-soluble compound having a heteropolyanion.

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, H⁺,
Alkali metal cations and the like;
Monium cation, ammonium cation and H⁺With
Is used. Here, the Anderson type Te-Mo
Telopolyanions are (TeMo_6-kV_kO_{twenty four}) ^{(6 + k)-}(K is 0
Or a heteropolyanion having the structure
And Anderson type Sb-Mo heteropolyanio
(SbMo_6-lV_lO_{twenty four})^{(7 + l)-}(L represents 0 or 1)
Is a heteropolyanion having the structure:

Specifically, (TeMo₆O_{twenty four}) (NH_Four)₆, (TeMo_Five
V₁O_{twenty four}) (NH_Four)₇, (TeMo₆O_{twenty four}) H (NH _Four)_FiveSuch as under
A compound containing a son-type Te-Mo heteropolyanion, (S
bMo_{6 -l}V_lO_{twenty four}) (NH_Four)₇, (SbMo_FiveV₁O_{twenty four}) (NH_Four)₈, (SbMo₆
O_{twenty four}) H (NH_Four)₆, Etc. Anderson Sb-Mo Hete
Compound containing ropolyanion, paramolybdate ammonium
Ni, MoO_Two(acac)_TwoMolybdenyl acetylene represented by
Luacetonate (however, acac is CH_ThreeCOCHCOCH_Three ^(-)
), Molybdenum halide, total by J. Zubieta
Theory, Molecular Engineering, Vol. 3, 93-120 (1993),
 CoordinationChemistry Reviews, Vol.114 107-167 (1
992) can be used
But preferably Anderson-type heteropolyaniline
Ammonium paramolybdate
Used. These Mo raw materials may be used alone or in combination of two or more.
May be.

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
and a water-soluble compound having a heteropolyanion containing o, most preferably a water-soluble compound having an Anderson-type Te-Mo heteropolyanion. In the Anderson type Te-Mo heteropolyanion, a part of Mo is V
May be substituted.

Specifically, (TeMo₆O_{twenty four}) (NH_Four)₆, (TeMo_Five
V₁O_{twenty four}) (NH_Four)₇, (TeMo₆O_{twenty four}) H (NH _Four)_FiveSuch as under
Compounds containing a son-type Te-Mo heteropolyanion,
Luluric acid, tellurium dioxide, tellurium trioxide, telluride halide
Can be used, but preferably Anderson type Te-
Compound containing Mo heteropolyanion, telluric acid, diacid
Telluride, more preferably Anderson type Te-Mo
Telopolyanions, telluric acid are used. These T
e 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, and more preferably Sb and Mo.
And particularly preferably Sb and M
and a water-soluble compound having a heteropolyanion containing o, most preferably a water-soluble compound having an Anderson Sb-Mo heteropolyanion. In the Anderson-type Sb-Mo heteropolyanion, a part of Mo is V
May be substituted.

Specifically, (SbMo _6-l V _l O ₂₄ ) (NH ₄ ) ₇ , (S
_{bMo 5 V 1 O 24) (} NH 4) 8, (SbMo 6 O 24) H (NH 4) 6, a compound containing an Anderson type SbMo heteropolyanion such as antimony oxide sol, Sb ₂ O _3, Sb ₂ O ₅ , antimony halide, antimony ammonium tartrate and 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 less than 5+. A compound consisting of V or a combination of a plurality of compounds having an average valence of V of 4+ or more and less than 5+, and particularly preferably having an average valence of V of substantially 4
+ Is a compound consisting of V. Such compounds include those reviewed by J. Zubieta, Molecular Engineerin
g, Vol. 3, 93-120 (1993) and Coordination Chemistry
Reviews, Vol. 114 107-167 (1992), vanadyl oxalate, vanadyl oxalate, vanadyl sulfate, vanadyl nitrate, vanadyl acetylacetonate represented by VO (acac) ₂ (acac is CH ₃ COCHCOCH ₃ ^(-) ), VCl _{4 and the} like. Particularly preferably, vanadyl sulfate is used. Raw materials having a valence of 5+, such as ammonium metavanadate or V ₂ O ₅ , can also be used by adding an appropriate amount of a reducing agent described below. These V raw materials may be used alone or in combination of two or more.

X is Ti, Zr, Nb, Ta, Cr, W, Mn, Fe, Ru, Co, Rh,
One or more elements selected from Ir, Ni, Pd, Pt, Cu, Ag, Zn, In, Sn, Pb, Bi and Ce, preferably one or more elements selected from Ti, Nb, Ta and W , More preferably Nb and / or
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, but is preferably a water-soluble compound, and specifically, an oxide sol, a hydroxide, or a water-soluble oxo acid of these elements. 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 above-mentioned metal-containing compound or ammonia water may be used, but an ammonium salt of the above-mentioned metal-containing compound is preferable. . These Mo, V, T
Each raw material of e, Sb, X, and NH ₄ is usually in water at room temperature or more and 90 ° C. or less, and usually 1 to 50 as a weight of a generated composite metal oxide.
% By weight, preferably 10 to 30% by weight, 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 obtained underwater raw material mixture may be subjected to pH adjustment or the like, if necessary.

As the metal raw material of the composite metal oxide of the present invention, a compound insoluble or hardly soluble in water may be used as long as at least one component is a compound in which at least a part thereof is soluble in water. When a compound insoluble or hardly soluble in water is used as the metal raw material, preferably, the Mo raw material and / or the V raw material are at least partially soluble in water, the Te raw material and / or the Sb raw material are insoluble in water or It is 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 dissolves in water. The dissolved at least a part of the compound reacts with a compound that is soluble in water, and the equilibrium of a compound that is insoluble or hardly soluble in water shifts by dissolving the insoluble or hardly soluble compound in water. Move, and sequentially insoluble or hardly soluble compounds dissolve in water, or a compound that is at least partially soluble in water reacts with water insoluble or hardly soluble compounds on its surface. It is presumed that the compound is dissolved as a water-soluble compound. In these raw materials, as a compound at least a part of which is soluble in water, usually 0.01 g in 100 g of water at normal temperature is used.
Compounds having the above-mentioned solubility are mentioned, and compounds insoluble or hardly soluble in water are usually compounds having a solubility of less than 0.01 g in 100 g of water at ordinary temperature.

The ratio of each component used as a raw material is usually
The ratio is set to be the same as the ratio of the obtained composite oxide.
The composition of each element of the target composite oxide is expressed by the number of Mo moles.
When it is 1.0, the molar ratio of V is 0.01 or more and less than 1.0, preferably 0.1 or more and less than 0.6, more preferably
0.2 or more and less than 0.5. When the number of moles of Mo is 1.0, the molar ratio 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 less than 0.20.
The molar ratio of the total amount of Te and Sb to the total amount of Mo, V and X is 0.
It is from 01 to 0.50, preferably from 0.03 to 0.25.

The amount of ammonium ions in the product varies depending on the production conditions, especially temperature and pH, but the molar ratio to the total amount of Mo, V and X is usually 0 or more and 1.0 or less. A substance having a reducing action may be added to the aqueous raw material mixture. By adding a substance having a reducing effect to the aqueous raw material mixture, it is possible to control the valence balance of Mo, V, Te, Sb, and X. The amount of the substance having a reducing action to be added to the aqueous raw material mixture is determined depending on the balance between the desired average metal valence, the average metal valence of the charge, and the reduction efficiency. Although it can not be determined, usually, usually not less than 0.01 mole times and not more than 20.0 mole times, preferably not more than the total number of moles of metal charged, preferably
It is added at a ratio of 0.1 mol times or more and 10.0 mol times or less.

Examples of the substance having a reducing property include inorganic amines such as hydroxylamine and hydrazine and salts thereof, aldehydes such as aliphatic aldehyde and aromatic aldehyde, and C7-carbon such as butanol and benzyl alcohol. The following alcohols, carboxylic acids having 4 or less carbon atoms such as oxalic acid and tartaric acid, and reducing sugars such as glucose can be used. It is desirable that both the reducing agent and the oxidized reducing agent are water-soluble in that they can be easily separated from the composite metal oxide formed by the hydrothermal treatment. The substances having a reducing action may be used alone or in combination of two or more.

The hydrothermal treatment is not particularly limited as long as it is under hydrothermal synthesis conditions, but the above-mentioned aqueous raw material mixture may be heated in a pressure vessel such as an autoclave and reacted. Hydrothermal treatment may be performed in the presence of residual air in the pressure vessel, or the residual air may be replaced with nitrogen prior to the hydrothermal treatment.However, in order to control the valence of the constituent elements, It is preferable to replace the remaining air with nitrogen.

The reaction temperature is not lower than 100 ° C. and not higher than 350 ° C.
Preferably, it is 150 ° C. or higher. Considering the reaction rate, the higher the temperature, the better. However, if the temperature is higher than 300 ° C., there is a disadvantage that the operation becomes difficult because the pressure reaches several tens of atmospheres. In addition, since the thermodynamic stability of the formed composite metal oxide is related to the selection of the operating temperature, it cannot be said that a high temperature is generally sufficient. A temperature of 150 ° C. or higher is preferred because the reaction is promoted.

The reaction pressure is usually a saturated steam pressure,
Preferably it is 4.5 to 85 atm. During the hydrothermal treatment, stirring may or may not be performed, but it is preferable to perform stirring in order to maintain homogeneity of the raw material in the system. The processing time of the hydrothermal treatment is usually 1 to 240 hours, preferably 4 to 200 hours. There is no particular limitation on the heating rate. 200 ° C
When the temperature is raised as described above, a stepwise temperature raising operation in which the temperature is maintained at a predetermined temperature in advance for a predetermined time and then re-heated to a target temperature is also possible. That is, if necessary depending on the combination of the constituent elements, etc., the temperature raising conditions divided into two times are also preferably used.

After the completion of the hydrothermal treatment, the mixture is cooled, and the formed water-insoluble solid is filtered, washed with water, and dried to obtain the composite metal oxide of the present invention. When mechanical strength is required depending on the use, 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. These carriers may be added at the time of hydrothermal synthesis, or may be mixed with the composite metal oxide after hydrothermal synthesis and subjected to firing described below.

The composite metal oxide thus obtained may be further heated and fired in the gas phase. Further, since the degree of crystallinity can be increased by baking, the baking is preferable when used at a temperature higher than the hydrothermal synthesis conditions. Further, the mechanical strength can be increased by baking after mixing with the carrier. Firing temperature is 35
The temperature is 0 ° C or higher, preferably 550 to 650 ° C. The firing time is usually 5 minutes to 20 hours, preferably 1 to 6 hours. The firing atmosphere is an atmosphere having an oxygen concentration lower than that of ordinary 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, and helium that contains substantially no oxygen. is there.

The composite metal oxide may be further subjected to post-treatments 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 vapor-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 a reaction for producing ethylene from ethane.

For example, when producing acrylonitrile and / or acrylic acid from propane, the mixed metal oxide catalyst obtained by the method of the present invention is placed in a reactor, and the reaction temperature is usually 350 to 500 ° C., and propane / The molar ratio of ammonia / oxygen / nitrogen is usually 1.0 / 0.1 to 3.0 / 0.1 to 1
The reaction gas having a space velocity SV of 0.0 / 0 to 50.0
It is manufactured by supplying to the reactor under the conditions of ⁰ to 30,000 h ^-1 . When simultaneously producing a nitrile and an α, β unsaturated carboxylic acid from an alkane, the nitrile and the α, β
A method for controlling the generation ratio of unsaturated carboxylic acid will be described below, taking as an example a case where acrylonitrile and acrylic acid are simultaneously produced from propane.

The control of the production ratio of acrylonitrile and acrylic acid cannot be specified unconditionally because it depends on the conversion rate 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 supplied propane / ammonia / oxygen is c / d / e, when 2c ≦ e, usually c ≦ d
Acrylonitrile can be produced as the main product under the condition of d, acrylonitrile and acrylic acid can be produced simultaneously under the condition of usually d ≦ c, and acrylic acid can be produced as the main product under the condition of usually d = 0. In the case of 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 acrylic can be produced under the condition of usually d = 0. The acid can be produced as the main product. In the case where the catalyst is used as a catalyst in this way, especially 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.

[0033]

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 selectivity, acrylic acid selectivity, acrylic acid yield, acrylonitrile formation rate, acrylonitrile + acrylic acid formation rate, and acrylic acid formation rate are calculated as follows.

WWH: weight of propane fed per unit time (hr) (kg) / weight of catalyst (kg) Propane conversion: moles of propane reacted / moles of propane supplied Acrylonitrile selectivity: formed acrylonitrile Number of moles / mole of reacted propane Acrylic acid selectivity: Number of moles of formed acrylic acid / mole number of reacted propane Propylene selectivity: Number of moles of propylene formed / mole of reacted propane Acrylic acid yield : Mole number of generated acrylic acid / mole number of supplied propane Acrylonitrile generation rate: Mass of acrylonitrile generated per unit time (hr) / mass of catalyst (kg) Acrylonitrile + acrylic acid generation rate: Unit time ( hr)
Of acrylonitrile produced per unit (kg) / mass of catalyst (kg) + mass of acrylic acid produced per unit time (hr)
(kg) / mass of catalyst (kg) Acrylic acid generation rate: mass of acrylic acid generated per unit time (hr) (kg) / mass of catalyst (kg)

<Example 1> First, the empirical formula was Mo ₁ V _0.27 Te
_0.18 Nb _0.15 (NH _{4) 0.28} complex metal oxide is O _n was synthesized as follows. Ammonium paramolybdate 7.1
g and 1.5 g of telluric acid were weighed and dissolved in 40 ml of water. Then, to this solution, vanadyl sulfate powder weighed so that V became 12 mmol was heated to 80 ° C. in 10 ml of hot water.
And a solution dissolved and added thereto to obtain a blue solution. Further, to this solution were added niobium pentoxide sol and 8.4 mmol of n-butanol weighed so that Nb became 4.8 mmol to obtain an aqueous mixture of the starting compounds. After stirring the aqueous mixture of the starting compounds for 10 minutes, the solution was placed in a Teflon inner cylinder simple stainless steel autoclave (100 ml) and sealed, and the remaining air in the autoclave was sufficiently replaced with nitrogen gas.
Heated at 5 ° C. (9.9 atm) for 48 hours. After the heating was completed, the autoclave was naturally cooled, and the generated solid was separated by filtration.
And the empirical formula is Mo ₁ V _0.27 Te _0.18 Nb _0.15 (NH ₄ ) _0.28 O
6.5 g of a black-purple solid, _n , was obtained. Next, 25 mg of the obtained solid was charged into a fixed bed flow type reactor, and a reaction temperature of 42 mg was used.
0 ° C, space velocity SV about 16000h ^-1 and propane /
Ammonia / air = gas supply at a molar ratio of 1 / 1.2 / 15,
A gas phase catalytic oxidation reaction was performed. The results are shown in Table 1.

Example 2 First, the empirical formula was Mo ₁ V _0.25 Te
_0.17 Nb _0.12 (NH _{4) 0.27} complex metal oxide is O _n was synthesized as follows. Known literature (Howard T. Evans. Jr. et al., Acta
Crystallographica (1974) .B30. 2095) to give the Anderson-type heteropoly acid _{((NH 4) 6 TeMo 6} O 24 · 7H 2 O) in accordance with. The heteropoly acid was weighed out so that Te became 6.6 mmol, and dissolved in 40 ml of water heated to 80 ° C. Next, to this solution, a solution in which vanadyl sulfate powder weighed so that V became 12 mmol was added to and dissolved in 10 ml of warm water heated to 80 ° C. was added to obtain a blue solution. Further, to this solution were added niobium pentoxide sol and 16.7 mmol of oxalic acid weighed so that Nb was 4.8 mmol to obtain an aqueous mixture of the starting compounds. After stirring the aqueous mixture of this raw material compound for 10 minutes, the solution was placed in a Teflon inner cylinder simple stainless steel autoclave (100 ml), sealed, and the residual air in the autoclave was sufficiently replaced with nitrogen gas.
(tm) for 48 hours. After autoclaving the natural cooling, the resulting solid was filtered off and dried at 80 ° C., empirical formula _{Mo 1 V 0.25 Te 0.17 Nb 0.12} (NH 4) 0.27 O n a a dark purple solid
6.6 g were obtained. Next, 25 mg of the obtained solid was charged into a fixed bed flow type reactor, and the reaction temperature was 420 ° C. and the space velocity was SV.
Propane / ammonia / air = 1 at about 16000h ^-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.

<Embodiment 3> First, the empirical formula is expressed as Mo ₁ V _0.27 Te
The composite metal oxide is _0.18 Nb _0.15 O _n was prepared as follows. The black-purple solid obtained in Example 1 was further treated at 600 ° C. for 2 hours under a nitrogen stream to obtain an empirical formula of Mo ₁ V
_A black composite metal oxide of _0.27 Te _0.18 Nb _0.15 O was obtained. Next, 50 mg of the obtained composite metal oxide was charged into a fixed bed flow type reactor, and the reaction temperature was 420 ° C. and the space velocity was SV.
Propane / ammonia / air = 1 / about 7900h ^-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 1 First, the empirical formula was Mo ₁ V _0.3 Te
_0.23 Nb _0.12 (NH _{4) 0.55} complex metal oxide is O _n was synthesized as follows. 1.38 kg of ammonium paramolybdate, 0.275 kg of ammonium metavanadate, and 0.413 kg of telluric acid were dissolved in 5.68 liters of warm water to prepare a uniform aqueous solution. This solution has a niobium concentration of 0.659.
mol / kg aqueous solution of ammonium niobium oxalate 0.61
8 kg was mixed to prepare a slurry. The slurry was dried at 200 ° C. using a spray drier to remove water, and a solid was obtained. The obtained solid is heated at 175 ° C (1.0atm) under a nitrogen stream.
In to the 48 hours of heat treatment, empirical formula Mo ₁ V _0.3 Te _{0. 23} Nb
Was obtained _0.12 (NH _{4) 0.55} black solid is O _n.

Next, 50 mg of the obtained solid was charged into a fixed bed flow type reactor, and the reaction temperature was 420 ° C., the space velocity SV was about 7,900 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 1 differs from Example 1 in that
It is a composite metal oxide with almost the same composition.
Table 1 shows that the catalyst of Example 1 obtained by hydrothermal treatment had better performance than the catalyst of Comparative Example 1 without hydrothermal treatment, although it was obtained by treatment at 48 ° C for 48 hours. Is excellent.

Comparative Example 2 First, the empirical formula was Mo ₁ V _0.3 Te
_0.23 Nb _0.12 (NH _{4) 0.42} complex metal oxide is O _n was synthesized as follows. In Comparative Example 1, the heat treatment was performed under a nitrogen stream, but the heat treatment was performed under an air stream, in the same manner as in Comparative Example 1, and the empirical formula was Mo ₁ V _0.3 Te _0.23 Nb _0.12 (NH ₄ ).
To give a black solid which is _0.42 O _n. Next, a gas phase catalytic oxidation reaction was performed in the same manner as in Comparative Example 1 using the obtained solid.
The results are shown in Table 1. Comparative Example 2 is a composite metal oxide having substantially the same composition as that of Example 1, and although all were obtained by performing the treatment at 175 ° C. for 48 hours, it can be seen from Table 1 that the hydrothermal treatment was performed. It can be seen that the catalyst of Example 1 obtained by hydrothermal treatment had better performance than the catalyst of Comparative Example 2 which did not.

Comparative Example 3 First, the empirical formula was Mo ₁ V _0.25 Te
_0.17 Nb _0.12 (NH _{4) 0.27} complex metal oxide is O _n was synthesized as follows. After stirring the aqueous mixture of the starting compounds obtained in Example 2 for 10 minutes, it was spray-dried at 200 ° C. to remove moisture, and a solid was obtained.
Empirical formula by 48 hours of heat treatment at 175 ° C. (1.0 atm) to obtain a black solid is _{Mo 1 V 0.25 Te 0.17 Nb 0.12} (NH 4) 0.27 O n. Then, 50 mg of the obtained black solid was charged into a fixed-bed flow reactor, and the reaction temperature was 420 ° C., the space velocity was about 7900 h ⁻¹ , and the gas ratio was propane / ammonia / air = 1 / 1.2 / 15. Was supplied to perform a gas phase catalytic oxidation reaction. The results are shown in Table 1. Comparative Example 3 is the same as Example 2
Using the same heteropolyacid raw material as in
Table 1 shows that the catalyst of Example 2 was obtained by hydrothermal treatment from Comparative Example 3 in which no hydrothermal treatment was performed, despite the fact that the composite metal oxides had substantially the same composition and were obtained by treating for 8 hours. It can be seen that is superior in performance.

Comparative Example 4 First, the empirical formula was Mo ₁ V _0.3 Te
The composite metal oxide is _0.23 Nb _0.12 O _n was prepared as follows. The solid obtained by spray drying in Comparative Example 1 was decomposed in air at 350 ° C. (1.0 atm) until the smell of ammonia disappeared, and then heat-treated at 600 ° C. (1.0 atm) in a nitrogen stream for 2 hours. empirical formula to obtain a composite metal oxide of the black is _{Mo 1 V 0.3 Te 0.23 Nb 0.12} O n. Next, a gas phase catalytic oxidation reaction was performed in the same manner as in Example 3 using the obtained solid. The results are shown in Table 1. Comparative Example 4 was obtained by performing a hydrothermal treatment as in Example 3 in the same manner as in Example 3 although the obtained composite metal oxide was subjected to a post-treatment at 600 ° C. for 2 hours under nitrogen. It can be seen from Table 1 that the resulting catalyst is superior in activity (acrylonitrile formation rate) and selectivity to the catalyst obtained without hydrothermal treatment.

<Embodiment 4> First, the empirical formula is expressed as Mo ₁ V _0.3 Sb.
_0.17 Nb _0.05 (NH _{4) 0.2} complex metal oxide is O _n was synthesized as follows. 7.1 g of ammonium paramolybdate (Mo 40
mmol) in 40 ml of water and 0.715 g of 31% hydrogen peroxide
Was added. Further, 0.96 g of antimony trioxide powder (Sb ₂ O ₃ ) was added, and the mixture was heated to 80 ° C. with stirring to completely dissolve. Next, vanadyl sulfate powder weighed so that V became 16 mmol was added to 10 ml of warm water heated to 80 ° C., and a dissolved solution was added to obtain a blue solution. Further, to this solution were added niobium pentoxide sol weighed so that Nb was 2.0 mmol, and 8.4 mmol of oxalic acid to obtain an aqueous mixture of the starting compounds. The aqueous mixture of the starting compounds is
After stirring for 0 minutes, the solution was placed in a Teflon inner cylinder simple stainless steel autoclave (100 ml), sealed, and the residual air in the autoclave was sufficiently replaced with nitrogen gas.
Heat at 9.9 atm for 48 hours. After autoclaving the natural cooling, the resulting solid was filtered off and dried at 80 ° C., empirical formula to give a dark purple solid 7.0g is _{Mo 1 V 0.3 Nb 0.05 Sb 0.17} (NH 4) 0.2 O n . Then, using the obtained solid,
A gas phase catalytic oxidation reaction was performed in the same manner as in Example 3. The results are shown in Table 1.

Comparative Example 5 First, the empirical formula was Mo ₁ V _0.3 Sb
_0.17 Nb _0.05 (NH _{4) 0.5} complex metal oxide is O _n was synthesized as follows. 15.7 g of ammonium metavanadate was dissolved in 325 ml of warm water, and 10.9 g of antimony trioxide powder was added thereto. This slurry was heated and stirred at 80 ° C. for 6 hours, and then 78.9 g of ammonium paramolybdate was added thereto. Further, an aqueous solution of ammonium niobium oxalate (containing 2.23 mol / kg of niobium) was added.
0 g was added. The slurry was evaporated to dryness and treated at 175 ° C. (1.0 atm) for 48 hours under a nitrogen stream. Next, a gas phase catalytic oxidation reaction was performed in the same manner as in Example 3 using the obtained solid. The results are shown in Table 1.

[0045]

[Table 1]

It can be seen from Table 1 that the catalyst obtained by the hydrothermal treatment has a higher activity (acrylonitrile generation rate) than the catalyst obtained without the hydrothermal treatment.

<Embodiment 5> First, the empirical formula is expressed as Mo ₁ V _0.32 Te
_0.17 Nb _0.12 (NH _{4) 0.23} complex metal oxide is O _n was synthesized as follows. Ammonium paramolybdate 7.1
g and 1.5 g of telluric acid were weighed and dissolved in 40 ml of water. Next, to this solution, vanadyl sulfate powder weighed so that V became 16 mmol was heated to 80 ° C. in 10 m of hot water.
The resulting solution was added to 1 and dissolved therein to obtain a blue solution. Further, niobium pentoxide sol and 11.7 mmol of oxalic acid weighed so that Nb was 4.8 mmol were added to this solution to obtain an aqueous mixture of the starting compounds. The aqueous mixture of the starting compounds is
After stirring for 0 minutes, the solution was placed in a Teflon inner cylinder simple stainless steel autoclave (100 ml) and sealed, and the air remaining in the autoclave was sufficiently replaced with nitrogen gas.
(9.9 atm) for 48 hours. After completion of the heating autoclave was naturally cooled, the resulting solid was filtered off and dried at 80 ° C., the dark purple solid 7.9g empirical formula is _{Mo 1 V 0.32 Te 0.17 Nb 0.12} (NH 4) 0.23 O n Obtained. Then the resulting solid 25
mg in a fixed bed flow type reactor, and the reaction temperature was 410
° C., and the space velocity SV of about 16000H ^-1 supplying a gas in a molar ratio of propane / ammonia / air = 1 / 0.3 / 4 was carried out vapor phase catalytic oxidation reaction. Table 2 shows the results.

<Example 6> In Example 5, propane was used.
A gas phase catalytic oxidation reaction was carried out in the same manner as in Example 5, except that the molar ratio was changed to /ammonia/air=1/0.2/4. Table-Results
It is shown in FIG. <Example 7> In Example 5, propane / ammonia /
A gas phase catalytic oxidation reaction was carried out in the same manner as in Example 5, except that the molar ratio of air was changed to 1 / 0.15 / 4. Table 2 shows the results.

Comparative Example 6 The procedure of Example 5 was repeated except that the reactor was filled with the composite metal oxide obtained in Comparative Example 1.
A gas phase catalytic oxidation reaction was performed in the same manner as in Example 5. Table 2 shows the results. Comparative Example 7 A gas phase catalytic oxidation reaction was performed in the same manner as in Example 6, except that the reactor was filled with the composite metal oxide obtained in Comparative Example 1. Table 2 shows the results. Comparative Example 8 A gas phase catalytic oxidation reaction was performed in the same manner as in Example 7, except that the reactor was filled with the composite metal oxide obtained in Comparative Example 1. Table 2 shows the results.

<Embodiment 8> First, the empirical formula is expressed as Mo ₁ V _0.32 Te
The composite metal oxide is _0.17 Nb _0.12 O _n was prepared as follows. The dark purple solid obtained in Example 5, further, by 2 hours under a nitrogen stream 600 ° C. (1.0 atm), complex metal black empirical formula is _{Mo 1 V 0.32 Te 0.17 Nb 0.12} O n An oxide was obtained. Next, 50 mg of the obtained composite metal oxide was charged into a fixed bed flow type reactor, and the reaction temperature was 410 ° C. and the space velocity SV was about 7900 h ⁻¹ , and propane / ammonia /
Gas was supplied at a molar ratio of air = 1 / 0.3 / 4 to perform a gas phase catalytic oxidation reaction. The results are shown in Table-2.

<Example 9> In Example 8, propane was used.
A gas phase catalytic oxidation reaction was carried out in the same manner as in Example 8 except that the molar ratio was changed to 1 / 0.2 / 4. Table-Results
It is shown in FIG. Example 10 A gas phase catalytic oxidation reaction was carried out in the same manner as in Example 8, except that the molar ratio was propane / ammonia / air = 1 / 0.15 / 4. Table 2 shows the results.

Comparative Example 9 First, the empirical formula was Mo ₁ V _0.3 Te
The composite metal oxide is _0.23 Nb _0.12 O _n was prepared as follows. The solid obtained by spray drying in Comparative Example 1 was decomposed in air at 350 ° C. (1.0 atm) until the smell of ammonia disappeared, and then heat-treated at 600 ° C. (1.0 atm) in a nitrogen stream for 2 hours. empirical formula to obtain a composite metal oxide of the black is _{Mo 1 V 0.3 Te 0.23 Nb 0.12} O n. Next, a gas phase catalytic oxidation reaction was performed in the same manner as in Example 8 using the obtained composite metal oxide. Table 2 shows the results.

Comparative Example 10 A gas phase catalytic oxidation reaction was carried out in the same manner as in Example 9 except that the reactor was filled with the composite metal oxide obtained in Comparative Example 9. Table 2 shows the results. <Comparative Example 11> In Example 10, Comparative Example 9 was added to the reactor.
Example 10 except that the composite metal oxide obtained in the above was filled.
A gas phase catalytic oxidation reaction was carried out in the same manner as described above. Table 2 shows the results.
Shown in

<Embodiment 11> First, the empirical formula is expressed as Mo ₁ V _0.3 Te.
_0.16 Nb _0.125 (NH _{4) 0.19} complex metal oxide is O _n was synthesized as follows. In Example 5, the empirical formula was Mo ₁ V _0.3 Te _0.16 N, except that the hydrothermal treatment time at 175 ° C. (9.9 atm) was changed from 48 hours to 12 hours.
The b _0.125 (NH ₄₎ complex metal oxide is a dark purple solid in _0.19 O _n was prepared. Next, using the obtained composite metal oxide,
A gas phase catalytic oxidation reaction was performed in the same manner as in Example 5. Table 2 shows the results.

Example 12 A gas phase catalytic oxidation reaction was carried out in the same manner as in Example 7, except that the reactor was filled with the composite metal oxide obtained in Example 11. Table 2 shows the results. <Example 13> First, empirical formula _{Mo 1 V 0.3 Te 0.16 Nb 0.125} O n
Was synthesized as follows. Example 1
The black-purple solid obtained in 1 was further heated at 600 ° C under a nitrogen stream.
(1.0atm) for 2 hours, the empirical formula is Mo ₁ V
The _0.3 Te _0.16 Nb _0.125 composite metal oxide black is O _n was synthesized. Next, 50 mg of the obtained composite metal oxide was charged into a fixed bed flow type reactor, and the reaction temperature was 410 ° C. and the space velocity S
V about 7900h ^-1 and propane / ammonia / air = 1
A gas was supplied at a molar ratio of /0.3/4 to perform a gas phase catalytic oxidation reaction. The results are shown in Table-2.

Example 14 A gas phase catalytic oxidation reaction was carried out in the same manner as in Example 10, except that the reactor was filled with the composite metal oxide obtained in Example 13. Table 2 shows the results.

Example 15 First, the empirical formula was Mo ₁ V _0.36 Te
_0.16 Nb _0.12 (NH _{4) 0.17} complex metal oxide is O _n was synthesized as follows. The empirical formula was Mo ₁ V _0.36 Te _0.16 Nb in the same manner as in Example 5 except that the hydrothermal treatment time at 175 ° C. (9.9 atm) was changed from 48 hours to 90 hours.
_0.12 was prepared (NH _{4) 0.17} O _n a a composite metal oxide. Next, a gas phase catalytic oxidation reaction was performed in the same manner as in Example 5 using the obtained composite metal oxide. Table 2 shows the results.

Example 16 A gas phase catalytic oxidation reaction was carried out in the same manner as in Example 10, except that the reactor was filled with the composite metal oxide obtained in Example 15. Table 2 shows the results.

Example 17 First, the empirical formula was expressed as Mo ₁ V _0.36 Te
The composite metal oxide is _0.16 Nb _0.12 O _n was prepared as follows. The black-purple solid obtained in Example 15 was further treated at 600 ° C. (1.0 atm) for 2 hours in a nitrogen stream to obtain
Empirical formula to obtain a composite metal oxide of the black is _{Mo 1 V 0.36 Te 0.16 Nb 0.12} O n. Next, 50 mg of the obtained composite metal oxide
Was charged into a fixed bed flow type reactor, a gas was supplied at a reaction temperature of 410 ° C. and a space velocity SV of about 7900 h ⁻¹ at a molar ratio of propane / ammonia / air = 1 / 0.3 / 4 to perform a gas phase catalytic oxidation reaction. Was done. Table 2 shows the results.

Example 18 A gas phase catalytic oxidation reaction was carried out in the same manner as in Example 10, except that the reactor was filled with the composite metal oxide obtained in Example 17. Table 2 shows the results. Example 19 First, the empirical formula was expressed as Mo ₁ V _0.36 Te _0.13 Ti _0.10 (N
H _{4) 0.23} composite oxide catalyst is O _n was prepared as follows. In Example 5, instead of niobium pentoxide sol,
The empirical formula was Mo ₁ V _0.36 Te _0.13 Ti _0.10 (NH _{4) in the same} manner as in Example 5 except that a titanium dioxide sol having a TiO ₂ content of 6% by weight was weighed so that Ti was 4 mmol. ) _0.23 O _n
Was prepared. Then, 100 mg of the obtained composite metal oxide was charged into a fixed bed flow type reactor, and the reaction temperature was 410 ° C., the space velocity SV was about 4000 h ⁻¹ , and the molar ratio was propane / ammonia / air = 1 / 0.3 / 4. Gas was supplied to perform a gas phase catalytic oxidation reaction. Table-Results
See Figure 2.

<Comparative Example 12> First, the empirical formula was Mo ₁ V _0.3 Te
_{0.17 Ti 0.10 (NH 4) 0.5} O n a a composite metal oxide was synthesized as follows. 7.1 g of ammonium paramolybdate,
1.5 g of telluric acid and 1.4 g of ammonium metavanadate were dissolved in 80 ml of warm water. In addition, 4m of Ti
Titanium dioxide sol having a TiO ₂ content of 6% by weight and 11.7 mmol of oxalic acid, which were weighed so as to be mol, were added and stirred. The slurry was evaporated to dryness and 175 ° C
(1.0 atm) for 48 hours in a nitrogen stream. Then
100 mg of the obtained composite metal oxide was charged into a fixed bed flow type reactor, and the reaction temperature was 410 ° C. and the space velocity SV was about 400.
A gas was supplied at a molar ratio of propane / ammonia / air = 1 / 0.3 / 4 at ⁰ h ⁻¹ to perform a gas phase catalytic oxidation reaction. The results are shown in Table-2.

Example 20 First, the empirical formula was Mo ₁ V _0.35 Te
_0.17 Ta _0.1 (NH _{4) 0.17} complex metal oxide is O _n was synthesized as follows. In Example 5, instead of niobium pentoxide sol, the content of Ta was measured so that Ta was 4 mmol.
0.66 mol / l tantalum oxalate solution was added a, also except that the 6.67mmol the amount of oxalic acid, examples empirical formula was prepared in analogy to 5 _{Mo 1 V 0. 35 Te 0.17 Ta} 0.1 (NH ₄ ) _0.17
Which is a O _n composite metal oxide was prepared. Next, 25 mg of the obtained composite metal oxide was charged into a fixed-bed flow reactor,
At a reaction temperature of 410 ° C. and a space velocity SV of about 16000 h ⁻¹ , a gas was supplied at a molar ratio of propane / ammonia / air = 1 / 0.3 / 4 to perform a gas phase catalytic oxidation reaction. Table 2 shows the results.
Shown in

Comparative Example 13 First, the empirical formula was Mo ₁ V _0.3 Te
_{0.17 Ta 0.1 (NH 4) 0.5} O n a a composite metal oxide was synthesized as follows. In Comparative Example 12, in place of the titanium dioxide sol, an aqueous solution of tantalum oxalate having a Ta content of 0.66 mol / l weighed so that Ta was 4 mmol was added,
Except that the 6.67mmol the amount of oxalic acid in the same manner as in Comparative Example 12, the empirical formula to prepare a composite metal oxide is _{Mo 1 V 0. 3 Te 0.17 Ta} 0.1 (NH 4) 0.5 O n. Then, 50 mg of the obtained composite metal oxide was charged into a fixed bed flow reactor, and the reaction temperature was 410 ° C., the space velocity SV was about 7,900 h ⁻¹ , and the gas ratio was propane / ammonia / air = 1 / 0.3 / 4. Was supplied to perform a gas phase catalytic oxidation reaction. The results are shown in Table-2.

Example 21 First, the empirical formula was Mo ₁ V _0.36 Te
_{0.17 W 0.09 (NH 4) 0.20} O n a a composite metal oxide was synthesized as follows. In Example 5, instead of the five niobium oxide sol, those W is dissolved ammonium paratungstate were weighed so as to be _{4mmol ((NH 4) 10 W} 12 O 41 · 5H 2 O) in warm water was added, oxalic acid The empirical formula was Mo ₁ V _0.36 Te _0.17 W in the same manner as in Example 5 except that the amount of addition was 13.5 mmol.
_0.09 was prepared (NH _{4) 0.20} O _n a a composite metal oxide. Next, 50 mg of the obtained composite metal oxide was charged into a fixed bed flow type reactor, and the reaction temperature was 410 ° C. and the space velocity SV was about 7900.
in the h ^-1 supplying a gas in a molar ratio of propane / ammonia / air = 1 / 0.3 / 4 was carried out vapor phase catalytic oxidation reaction. The results are shown in Table-2.

<Comparative Example 14> First, the empirical formula was Mo.
_{1 V 0.3 Te 0.17 W 0.1 (} NH 4) complex metal oxide is _0.5 O _n was synthesized as follows. In Comparative Example 12, in place of the titanium dioxide sol, W is ammonium paratungstate were weighed so as to be 4mmol the _{((NH 4) 10 W 12} O 41 · 5H 2 O) Hot water
Add the solution dissolved in 10 ml and add the amount of oxalic acid to 13.5 mm
except that the ol in the same manner as in Comparative Example 12, empirical formula is empirical formula was prepared _{Mo 1 V 0.3 Te 0.17 W 0.1} (NH 4) complex metal oxide is _0.5 O _n. Next, the obtained composite metal oxide 50 m
g in a fixed-bed flow reactor, and the reaction temperature was 410 ° C.
A gas was supplied at a space velocity SV of about 7900 h ^-1 at a molar ratio of propane / ammonia / air = 1 / 0.3 / 4 to perform a gas phase catalytic oxidation reaction. The results are shown in Table-2.

[0066]

[Table 2]

In the table, PPA represents propane, AN represents acrylonitrile, and AA represents acrylic acid. In both the case where acrylonitrile is produced as the main product from propane and the case where acrylonitrile and acrylic acid are produced at the same time, the catalyst obtained by hydrothermal treatment is more active than the catalyst obtained without hydrothermal treatment. (Acrylonitrile + acrylic acid generation rate) is excellent from Table-2.

<Example 22> The composite oxide 50 of Example 5
mg into a fixed bed flow type reactor, and the reaction temperature was 410
° C, space velocity about 26000 hr ^-1 and propane / H ₂ O
Gas was supplied at a molar ratio of 1/12/4 to perform a gas phase catalytic oxidation reaction. The results after 3 hours are shown in Table-3. The reaction results were stable for a long time.

Comparative Example 15 First, the empirical formula was Mo ₁ V _0.3 Te
_0.17 Nb _0.12 (NH _{4) 0.55} complex metal oxide is O _n was synthesized as follows. In Comparative Example 1, the amount of telluric acid was
The experimental formula was Mo ₁ V _0.3 Te in the same manner as in Comparative Example 1 except that g was used.
_0.17 was synthesized Nb _0.12 (NH _{4) 0.55} complex metal oxide is O _n. Next, a gas phase catalytic oxidation reaction was performed in the same manner as in Example 22 using the obtained composite metal oxide. As a result, unlike Example 22, not only the conversion rate of propane was extremely low, but also a phenomenon that the activity decreased with time was observed, and the acrylic acid production rate at 1.5 hours after the start of the reaction was 0.1%.
It was 2kg-AA / kg-cat / hr, but it was 0.0
It decreased to 6kg-AA / kg-cat / hr. The results after 2.5 hours are shown in Table-3.

Example 23 First, the empirical formula was Mo ₁ V _0.32 Te
The composite metal oxide is _0.17 Nb _0.12 O _n was prepared as follows. The empirical formula obtained in Example 5 used in Example 22 is
_{Mo 1 V 0.32 Te 0.17 Nb 0.12} (NH 4) 0.23 O n a a composite metal oxide further, by 2 hours under a nitrogen stream 600 ° C. (1.0 atm), empirical formula Mo ₁ V _0.32 Te _0.17 to obtain a composite metal oxide of the black is nb _0.12 O _n. Next, a gas phase catalytic oxidation reaction was carried out in the same manner as in Example 22 using 100 mg of the obtained composite metal oxide. The results are shown in Table-3. The reaction results were stable for a long time.

Comparative Example 16 First, the empirical formula was Mo ₁ V _0.3 Te
The composite metal oxide is _0.17 Nb _0.12 O _n was prepared as follows. The composite metal oxide obtained in Comparative Example 15 was treated with 35
0 ℃ After ammonia odor was decomposed until no in (1.0 atm), and a heat treatment for 2 hours under a nitrogen stream 600 ℃ (1.0atm), empirical formula is _{Mo 1 V 0.3 Te 0.17 Nb 0.12} O n A black composite oxide was obtained. Then, the obtained composite oxide 100 m
Using g, a gas phase catalytic oxidation reaction was carried out in the same manner as in Example 23. The results are shown in Table-3.

[0072]

[Table 3]

In the table, PPA is propane, AA is acrylic acid, P
PY represents propylene. Also in the case of producing acrylic acid from propane, the catalyst obtained by the hydrothermal treatment has a higher activity (acrylic acid generation rate) than the catalyst obtained without the hydrothermal treatment. 3

<Example 24> First, the empirical formula was Mo.₁V_0.3Te
_0.17Nb_0.12O_nIs synthesized as follows
did. Teflon inner cylinder simple stainless steel autoclave (10
0 ml), 50 ml of water and molybdenum trioxide (MoO_Three) 5.76g
 , Tellurium dioxide (TeO_Two) 1.06 g, vanadium pentoxide (V
_TwoO _Five) 1.09g, oxalic acid dihydrate (H_TwoC_TwoO_Four・ 2H_TwoO) 1.51 g,
Niobium pentoxide sol weighed so that Nb is 4.8 mmol
After addition, mix well and seal.
After sufficiently replacing the existing air with nitrogen gas, the same as in Example 1 is performed.
Heated at 175 ° C. (9.9 atm) for 48 hours. Autoclave
After natural cooling, the solid formed is filtered off and dried at 80 ° C.
The empirical formula is Mo₁V_0.3Te_0.17Nb_0.12O_nIs a composite metal acid
7.0 g of the compound were obtained. Next, the obtained composite metal oxide 25
mg in a fixed bed flow reactor as in Example 1 and
Temperature 420 ℃, space velocity SV about 16000h^-1To
Gas at a molar ratio of propane / ammonia / air = 1 / 1.2 / 15
Was supplied to perform a gas phase catalytic oxidation reaction. Table 4 shows the results
Show.

Comparative Example 17 First, the empirical formula was Mo ₁ V _0.3 Te
The composite metal oxide is _0.17 Nb _0.12 O _n was prepared as follows. Molybdenum trioxide (MoO ₃ ) 5.76 g in 50 ml of water,
1.06 g of tellurium dioxide (TeO ₂ ), vanadium pentoxide (V ₂ O ₅ )
1.09 g, oxalic acid dihydrate _{(H 2 C 2 O 4 ·} 2H 2 O) 1.51g, Nb is
Niobium pentoxide sol weighed to 4.8 mmol was added, and the slurry obtained by sufficiently stirring was evaporated to dryness with stirring. The obtained solid is crushed, and under a nitrogen stream (1.0 atm)
175 ° C. and for 48 hours, empirical formula Mo ₁ V _0.3 Te
A _0.17 Nb _0.12 O _n was obtained composite metal oxide. Then
50 mg of the obtained composite metal oxide was charged into a fixed bed flow type reactor, and the reaction temperature was 420 ° C. and the space velocity SV was about 7900 h ^−1.
A gas was supplied at a molar ratio of propane / ammonia / air = 1 / 1.2 / 15 to perform a gas phase catalytic oxidation reaction. The results are shown in Table-4.

Example 25 First, the empirical formula was Mo ₁ V _0.3 Te
The composite metal oxide is _0.17 Nb _0.12 O _n was prepared as follows. The black purple solid obtained in Example 24 was further treated at 600 ° C. for 2 hours under a nitrogen stream (1.0 atm) to obtain
Empirical formula to obtain a composite metal oxide of the black is _{Mo 1 V 0.3 Te 0.17 Nb 0.12} O n. Next, 50 mg of the obtained composite metal oxide was charged into a fixed bed flow type reactor, and the reaction temperature was 420 ° C., the space velocity was about 7900 h ⁻¹ , and propane / ammonia / air
Gas was supplied at a molar ratio of = 1 / 1.2 / 15 to perform a gas phase catalytic oxidation reaction. The results are shown in Table-4.

Comparative Example 18 First, the empirical formula was Mo ₁ V _0.3 Te
The composite metal oxide is _0.17 Nb _0.12 O _n was prepared as follows. The solid obtained in Comparative Example 17, further, by treatment under a stream of nitrogen (1.0 atm) at 600 ° C. 2 hours, the mixed metal oxide of black empirical formula is _{Mo 1 V 0.3 Te 0.17 Nb 0.12} O n I got Next, a gas phase catalytic oxidation reaction was carried out in the same manner as in Example 25, using the obtained composite metal oxide. Table-Results
It is shown in FIG.

[0078]

[Table 4] In the table, PPA represents propane and AN represents acrylonitrile.

According to Table 4, Example 24 uses exactly the same as Comparative Example 17, that is, tellurium dioxide which is insoluble or hardly soluble in water alone, and molybdenum trioxide which is at least partially soluble in water. It can be seen that, despite the treatment at 175 ° C., the catalyst performance is much better than that of Comparative Example 17 without hydrothermal treatment. In Example 25, the same treatment as in Comparative Example 18 was carried out at 600 ° C. by using tellurium dioxide which is insoluble or hardly soluble in water alone, molybdenum trioxide at least partially soluble in water, and the like. Despite this, it can be seen that the catalyst performance is much better than Comparative Example 18 without hydrothermal treatment.

[0080]

According to the present invention, a composite metal oxide catalyst comprising Mo, V, and Te and / or Sb as essential components at a lower temperature as compared with the conventional method by selecting hydrothermal conditions. Can be synthesized, and a catalyst having good performance such as selectivity and activity can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 31/02 102 B01J 31/02 102Z C01G 51/00 C01G 51/00 A 53/00 53/00 A 55 / 00 55/00 C07C 51/25 C07C 51/25 57/05 57/05 253/24 253/24 255/08 255/08 // C07B 61/00 300 C07B 61/00 300 F-term (reference) 4G048 AA03 AB05 AC08 AE05 4G069 AA08 AA09 BB06A BB06B BB07A BB07B BC18A BC21A BC22A BC25A BC26A BC31A BC32A BC35A BC43A BC50A BC51A BC54A BC54B BC54C BC55A BC55B BC55C BC56A BC58A BC59A BC59B BC59C BC60A BC62A BC66A BC67A BC68A BC70A BC71A BC72A BC74A BC75A BD06A BD06B BD10A BD10B CB54 FB10 FB30 FC03 4H006 AA02 AC46 AC54 BA05 BA07 BA08 BA10 BA11 BA12 BA13 BA14 BA15 BA16 BA19 BA20 BA21 BA22 BA23 BA24 BA25 BA26 BA30 BA34 BA81 BC13 BC32 BC37 BE14 BE3 0 BS10 QN24 4H039 CA65 CA70 CC30 CL50

Claims (15)

[Claims] 1. An aqueous mixture containing a starting compound is mixed with 100 parts
A method for producing a composite metal oxide represented by the following general formula [1], wherein a hydrothermal treatment is performed at a temperature of 350 to 350 ° C. ## STR1 ## _{Mo 1.0 V a Te b Sbα -b} X x (NH 4) y O n [1] ( wherein, X is Ti, Zr, Nb, Ta, Cr, W, M
n, Fe, Ru, Co, Rh, Ir, Ni, Pd, P
represents one or more elements selected from t, Cu, Ag, Zn, In, Sn, Pb, Bi, 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 + x), n is a number determined by the oxidation state of another element. ) 2. In the general formula [1], 0.1 ≦ a <0.6, 0
≦ b ≦ α, 0.02 ≦ x <0.30, 0.03 ≦ α / (1 + a + x) ≦ 0.25, 0
The method for producing a composite metal oxide according to claim 1, wherein ≤ y ≤ (1 + a). 3. The Mo raw material is a water-soluble Mo compound, the V raw material is a water-soluble V compound, the Te raw material is a water-soluble Te compound, and the Sb raw material is a water-soluble Sb compound.
Or the method for producing a composite metal oxide according to 2. 4. Te and Mo raw materials are (TeMo _6-k V _k O ₂₄ )
The composite metal according to any one of claims 1 to 3, which is an Anderson-type Te-Mo heteropolyacid represented by ^{(6 + k)-} (k represents 0 or 1) or a salt thereof. A method for producing an oxide. 5. The raw material of Sb and Mo is (SbMo _6-k V _k O ₂₄ )
The composite metal according to any one of claims 1 to 3, which is an Anderson-type Sb-Mo heteropolyacid represented by ^{(7 + k)-} (k represents 0 or 1) or a salt thereof. A method for producing an oxide. 6. The composite metal oxide according to claim 1, wherein the V raw material is a combination of V compounds such that the average valence n of V satisfies 4 ≦ n <5. Method of manufacturing a product. 7. The method for producing a composite metal oxide according to claim 1, wherein a substance having a reducing action is added to the aqueous mixture containing the raw material compound. 8. A substance having a reducing action is an inorganic amine,
The method for producing a composite metal oxide according to claim 7, which is at least one selected from aldehydes, alcohols having 7 or less carbon atoms, carboxylic acids having 4 or less carbon atoms, and reducing sugars. 9. The method for producing a composite metal oxide according to claim 1, wherein the composite metal oxide obtained by the hydrothermal treatment is further calcined at a temperature of 350 ° C. or higher. . 10. The method for producing a composite metal oxide according to claim 9, wherein the firing atmosphere is an oxygen concentration atmosphere lower than air. 11. A composite metal oxide catalyst obtained by the production method according to claim 1. Description: 12. A method for producing a nitrile by ammoxidizing an alkane in the presence of a catalyst, wherein the composite metal oxide catalyst according to claim 11 is used as a catalyst. 13. 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 metal oxide catalyst according to claim 11 is used as a catalyst. A method for producing an α, β unsaturated carboxylic acid. 14. A method for producing a nitrile and an α, β unsaturated carboxylic acid by subjecting an alkane to a gas phase reaction in the presence of the composite metal oxide catalyst according to claim 11 in the presence of ammonia and oxygen, wherein the catalyst is supplied to a reactor. A method for producing a nitrile and an α, β-unsaturated carboxylic acid, characterized by controlling the ratio of the nitrile to be generated and the α, β-unsaturated carboxylic acid by changing the ratio of ammonia, alkane and oxygen. 15. The production method according to claim 12, wherein the alkane is propane or isobutane.