JP4050904B2 - Method for producing oxidation or ammoxidation catalyst - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an oxide catalyst used for gas phase catalytic oxidation or gas phase catalytic ammoxidation reaction of propane or isobutane, an oxide catalyst, and a method for producing an unsaturated acid or an unsaturated nitrile using the oxide catalyst. .
[0002]
[Prior art]
Conventionally, a process for producing a corresponding unsaturated carboxylic acid or unsaturated nitrile by vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation of propylene or isobutylene is well known, but in recent years propane or isobutylene is replaced by propane or isobutylene. A method for producing a corresponding unsaturated carboxylic acid or unsaturated nitrile by gas phase catalytic oxidation or gas phase catalytic ammoxidation of isobutane has attracted attention, and various oxide catalyst production methods have been proposed.
[0003]
For example, a method for producing an oxide catalyst containing Mo-V-Nb- (Te / Sb) is disclosed in JP-A-6-279351, JP-A-6-285372, JP-A-7-315842, and JP-A-8. -141401, JP-A-9-157241, JP-A-10-330343, JP-A-11-42434, JP-A-11-43314, JP-A-11-226408, JP-A-10-57479. JP, JP-A 2000-70714, JP-A 2000-143244, JP-A 2001-58827, JP-A 2001-180936, JP-A 2001-130913, JP-A 2001-122625. JP-A-2001-122624 and the like.
[0004]
Moreover, the manufacturing method of the oxide catalyst for acrylic acid manufacture containing Mo-V-Sb is disclosed in Japanese Patent Laid-Open Nos. 10-45664, 2000-354765, 2000-317309, and 2000-. No. 254496, JP-A 2000-256257, JP-A 2000-246108, JP-A 2000-51693, JP-A 11-285636, JP-A 11-285637, JP-A 10-230164 This is disclosed in Japanese Patent Laid-Open No. 2001-70788.
[0005]
A mixed solution composed of a plurality of types of metal ions, particularly a mixed solution containing niobium, has a pH stability region in which each metal ion is different, so that the stability as a solution is extremely low, and gelation and precipitation are likely to occur. Therefore, Japanese Patent Laid-Open No. 7-315842 proposes a manufacturing method in which moisture is removed from a solution before the mixed solution of Mo—V—Nb— (Te / Sb) is precipitated. However, since the time from the addition of niobium to the occurrence of precipitation is several minutes to several tens of minutes, in mass production that requires several hours or more for removing water from the raw material preparation liquid, during the process of removing water from the solution Then, precipitation occurs from at least a part of the solution before moisture removal. Therefore, it has been difficult to apply this method to mass production.
[0006]
On the other hand, the raw material preparation liquid composed of Mo-V-Nb- (Te / Sb) has a characteristic that it is very easy to gel in an unstirred state. If the raw material preparation liquid has the property of being easily gelled, the component composition is locally non-uniform, which may cause a decrease in the activity of the resulting catalyst and a decrease in the selectivity of the target product. In JP-A-2001-180936, JP-A-2001-130913, JP-A-2001-122625, and JP-A-2001-122624, a method for producing an oxide catalyst for homogenizing a solution or slurry containing niobium is disclosed. Although proposed, there was no detailed description of gelation or stirring of the slurry.
[0007]
However, when manufacturing catalysts on an industrial scale, no stirring is required for a short time, such as when switching liquid pumps, feeding a small amount of raw material mixture, or clogging in piping, or in trouble with various equipment. In many cases, the performance of the resulting catalyst tended to be lower than that of the catalyst produced on a small scale. Accordingly, there has been a strong demand for a method for producing an oxide catalyst that determines an allowable no-stirring time and has a large amount of reproducible and excellent performance.
[0008]
[Problems to be solved by the invention]
An object of the present invention is a method for producing a novel oxide catalyst for use in the production of an unsaturated acid or an unsaturated nitrile, which suppresses the heterogeneous component composition due to gelation and reduces the catalyst performance. The objective is to produce a large amount with good reproducibility.
[0009]
[Means for Solving the Problems]
As a result of intensive studies on a method for producing an oxide catalyst used for gas phase catalytic oxidation or gas phase catalytic ammoxidation reaction of propane or isobutane, the inventors have determined that the non-stirring time for the raw material mixture is within 1 hour. The present inventors have found that the above problems can be solved, and have made the present invention.
That is, the present invention comprises the following aspects.
[0010]
[1] A method for producing an oxide catalyst for use in a gas phase catalytic oxidation reaction or gas phase catalytic ammoxidation reaction of propane or isobutane, comprising (I) a raw material preparation step, (II) a drying step, and (III) a firing step. become, in (I) the raw material preparation step, the catalyst component is not a niobium hydrogen peroxide / niobium molar ratio of 0. mixing the niobium mixture containing 5-20, Hitakara stirring blade in raw material mixture in The method for producing an oxide catalyst is characterized in that the non-stirring time during which the raw material mixture is not stirred is within one hour.
[2] The method for producing an oxide catalyst according to [1], wherein the non-stirring time for the raw material preparation liquid is set to 20 minutes or less.
[0011]
[ 3 ] The method for producing an oxide catalyst according to [1] or [ 2 ] , wherein the oxide catalyst is represented by the following general composition formula (1):
_{Mo 1 V a Nb b X c} O n (1)
(In the formula, component X is at least one element selected from tellurium or antimony, a, b, c, and n represent an atomic ratio per Mo atom, and a is 0.01 ≦ a ≦ 1, b. Is 0.01 ≦ b ≦ 1, c is 0.01 ≦ c ≦ 1, and n is a number determined by the valence of the constituent metals.)
[0012]
[ 4 ] The method for producing an oxide catalyst according to any one of [1] to [ 3 ], wherein the component X is antimony.
[ 5 ] Any one of [1] to [ 4 ], wherein the niobium raw material is a niobium-containing liquid containing a dicarboxylic acid / niobium compound and having a dicarboxylic acid / niobium molar ratio of 1 to 4 . 2. A method for producing the oxide catalyst according to item 1.
[ 6 ] The oxide catalyst is composed of a catalyst constituent element oxide represented by the general composition formula (1) and silica supporting the catalyst, and the content ratio of the silica is the catalyst constituent element. The oxide catalyst according to any one of [1] to [ 5 ], which is supported on 20 to 60% by weight of silica in terms of SiO ₂ with respect to the total weight of the oxide and silica. Production method.
[0013]
[ 7 ] An oxide catalyst is produced by the method according to any one of [ 1] to [6], and propane or isobutane is brought into contact with the obtained oxide catalyst to produce a corresponding unsaturated acid or unsaturated compound. A method for producing nitrile.
[0014]
Hereinafter, the present invention will be described in detail.
The method for producing an oxide catalyst of the present invention comprises (I) a step of preparing a raw material, (II) a step of drying the raw material preparation liquid obtained in step (I) to obtain a catalyst precursor, and a step (III) ( The catalyst precursor obtained in II) can be produced through three steps of calcination.
The preparation in the present invention is to dissolve or disperse the raw material of the catalyst constituent element in the aqueous solvent. The raw material preparation liquid represents a solution, an aqueous mixture or a slurry containing all of the catalyst constituent metal and the carrier component. When several catalyst components are added in the vicinity of the dryer inlet, a solution, an aqueous mixture or a slurry containing all catalyst constituent metals and carrier components other than the added components is used as a raw material preparation solution.
[0015]
Stirring in the present invention is to give fluidity to an aqueous solvent. Stirring can be performed using a general stirring blade, a stirring blade, etc., but it is preferable to use a stirring blade for high viscosity liquid, and it is more preferable to use a multistage blade, an anchor blade, a spiral shaft blade, and a spiral belt blade. preferable. Propellers, disk turbines, fan turbines, curved blade fan turbines, arrow blade turbines, angled blade turbines, and the like, which are low-viscosity liquid stirring blades, can be used, and more preferably used together with baffle plates.
The non-stirring state of the present invention is not only the state in which stirring in a container capable of stirring the raw material preparation liquid is stopped, but also the stirring blade is not immersed in the raw material preparation liquid, and stirring to the raw material preparation liquid This includes situations where this is impossible. Further, the non-stirring time is the time from the start of the unstirred state of the raw material preparation liquid to the end.
[0016]
The catalyst obtained by the production method of the present invention is an oxide catalyst represented by the following general composition formula (1).
_{Mo 1 V a Nb b X c} O n (1)
(In the formula, component X is at least one element selected from tellurium or antimony, a, b, c, and n represent an atomic ratio per Mo atom, and a is 0.01 ≦ a ≦ 1, b. Is 0.01 ≦ b ≦ 1, c is 0.01 ≦ c ≦ 1, and n is a number determined by the valence of the constituent metals.)
The atomic ratios a to c per Mo atom are preferably 0.1 to 0.4, 0.01 to 0.2, and 0.1 to 0.5, respectively.
[0017]
The oxide catalyst obtained by the production method of the present invention is preferably a silica-supported catalyst. When the oxide catalyst is a silica-supported catalyst, it has a high mechanical strength, and therefore is suitable for a gas phase catalytic oxidation reaction or a gas phase catalytic ammoxidation reaction using a fluidized bed reactor. The content of the silica support is preferably 20 to 60% by weight, more preferably 25 to 60% by weight in terms of SiO _{2 with} respect to the total weight of the silica-supported oxide catalyst comprising the oxide of the catalyst constituent element and the silica support. 55% by weight.
[0018]
The raw material is used in step (I). Although the raw material used by the preparation method of this invention is not specifically limited, What does not contain the component which deteriorates catalyst performance is preferable. In addition, it is preferable that the raw material for the carrier component and the solvent such as water do not substantially contain a component that deteriorates the catalyst performance.
As the raw material, for example, the following compounds can be used.
As the raw material of Mo, ammonium heptamolybdate [(NH ₄ ) ₆ Mo ₇ O ₂₄ · 4H ₂ O] can be suitably used.
[0019]
As the raw material for V, ammonium metavanadate [NH ₄ VO ₃ ] can be preferably used.
As a raw material of Nb, niobic acid, an inorganic acid salt of niobium, and an organic acid salt of niobium can be used. Niobic acid is particularly good. Niobic acid is represented by Nb ₂ O ₅ .nH ₂ O and is also referred to as niobium hydroxide or niobium oxide hydrate. Furthermore, it is preferable to use as a Nb raw material liquid having a dicarboxylic acid / niobium molar ratio of 1 to 4. By setting the molar ratio of dicarboxylic acid / niobium to the above value, the oxidation-reduction state of the metal constituting the catalyst can be adjusted and the catalyst performance can be made particularly excellent. The dicarboxylic acid is preferably oxalic acid.
[0020]
As a raw material of Sb, diantimony trioxide [Sb ₂ O ₃ ] is preferable. Furthermore, in order to improve the dissolution rate of Sb in an aqueous solvent, it is preferable to use Sb ₂ O ₃ having an average particle diameter of 1 μm or less. As a raw material for Te, telluric acid [H ₆ TeO ₆ ] is preferable. The silica raw material is preferably silica sol.
Below, the preferable catalyst preparation example of this invention which consists of process (I)-(III) is demonstrated.
[0021]
(Process I: Raw material preparation process)
A raw material preparation liquid is obtained using the raw materials described above. An example is shown below.
Ammonium heptamolybdate, ammonium metavanadate, and antimony trioxide are added to water and heated to 70 ° C. or higher to prepare a mixed solution (A). At this time, the inside of the container may be a nitrogen atmosphere.
Niobic acid and oxalic acid are heated and stirred in water to prepare a niobium-containing liquid (B ₀ ). As the containing liquid (B ₀ ), a containing liquid obtained by the method taught in JP-A-11-253801 can be used. Furthermore, hydrogen peroxide and antimony trioxide are added to at least a part of the containing liquid (B ₀ ) to prepare a niobium mixed liquid (B). In this, H ₂ O ₂ / Nb (molar ratio) is 0.5 to 20, especially 1 to 10 are preferred, Sb / Nb (molar ratio) is 0-5, especially 0.01 to 2 is preferred. Oxalic acid can also be added to the mixed solution (B).
[0022]
According to the target composition, the mixed solution (A), the mixed solution (B), and the containing solution (B ₀ ) are suitably mixed to obtain a raw material preparation solution.
By reducing the non-stirring time of the obtained raw material preparation liquid within 1 hour, preferably within 20 minutes, it is possible to suppress a decrease in catalyst performance.
When the catalyst for ammoxidation of the present invention is a silica-supported catalyst, the raw material preparation liquid is prepared so as to contain silica sol. Silica sol can be added as appropriate.
Moreover, when using antimony, it is preferable to add hydrogen peroxide to the liquid mixture (A) or the liquid containing the component of the liquid mixture (A) in the middle of preparation. At this time, H ₂ O ₂ / Sb (molar ratio) is 0.01 to 5, especially 1 to 3 are preferred. At this time, it is preferable to continue stirring at 30 ° C. to 70 ° C. for 30 minutes to 2 hours.
[0023]
(Process II: Drying process)
The raw material preparation liquid obtained in the step (I) is dried by a spray drying method to obtain a dry powder. The atomization in the spray drying method can employ a centrifugal method, a two-fluid nozzle method, or a high-pressure nozzle method. As the drying heat source, air heated by steam, an electric heater or the like can be used. The dryer inlet temperature of hot air is preferably 150 to 300 ° C.
[0024]
(Step III: Firing step)
An oxide catalyst is obtained by firing the dry powder obtained in the drying step. Firing is performed in an inert gas atmosphere substantially free of oxygen such as nitrogen gas, argon gas, helium gas, preferably at 500 to 800 ° C., preferably 600 to 700 ° C. while circulating the inert gas. . The firing time is 0.5 to 20 hours, preferably 1 to 8 hours.
[0025]
Firing can be performed using a rotary furnace, tunnel furnace, tubular furnace, fluidized firing furnace, or the like, but it is preferable to use a rotary furnace for mass firing.
Firing can be repeated. Prior to the firing step, the dried powder can be pre-fired at 200 to 400 ° C. for 1 to 5 hours in an air atmosphere or under air flow.
Propane or isobutane is subjected to gas phase catalytic oxidation or gas phase catalytic ammoxidation reaction in the presence of the oxide catalyst thus prepared to produce the corresponding unsaturated acid or unsaturated nitrile.
[0026]
The feedstock for propane or isobutane and ammonia does not necessarily have to be high purity, and industrial grade gases can be used.
Air, oxygen-enriched air, or pure oxygen can be used as the supply oxygen source. Further, helium, argon, carbon dioxide gas, water vapor, nitrogen or the like may be supplied as a dilution gas.
The gas phase catalytic oxidation of propane or isobutane can be carried out under the following conditions. The molar ratio of oxygen supplied to the reaction to propane or isobutane is 0.1 to 6, preferably 0.5 to 4.
[0027]
The reaction temperature is 300 ° C to 500 ° C, preferably 350 ° C to 450 ° C.
The reaction pressure is 5 × 10 ^{4 to} 5 × 10 ⁵ Pa, preferably 1 × 10 ^{5 to} 3 × 10 ⁵ Pa.
The contact time is 0.1 to 10 (sec · g / cc), preferably 0.5 to 5 (sec · g / cc). In the present invention, the contact time is determined by the following equation.
Contact time (sec · g / cc) = (W / F) × 273 / (273 + T)
Where W = filled catalyst amount (g)
F = Raw material mixed gas flow rate (Ncc / sec) at standard condition (0 ° C., 1.013 × 10 ⁵ Pa)
T = reaction temperature (° C.)
It is.
[0028]
The gas phase catalytic ammoxidation of propane or isobutane can be carried out under the following conditions.
The molar ratio of oxygen supplied to the reaction to propane or isobutane is 0.1 to 6, preferably 0.5 to 4.
The molar ratio of ammonia to propane or isobutane supplied to the reaction is 0.3 to 1.5, preferably 0.8 to 1.0.
[0029]
The reaction temperature is 350 ° C to 500 ° C, preferably 380 ° C to 470 ° C.
The reaction pressure is 5 × 10 ^{4 to} 5 × 10 ⁵ Pa, preferably 1 × 10 ^{5 to} 3 × 10 ⁵ Pa.
The contact time is 0.1 to 10 (sec · g / cc), preferably 0.5 to 5 (sec · g / cc).
As the reaction method, a conventional method such as a fixed bed, a fluidized bed, or a moving bed can be adopted, but a fluidized bed reactor in which reaction heat can be easily removed is preferable.
The reaction of the present invention may be a single flow type or a recycle type.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the oxide catalyst obtained by the production method of the present invention will be described using a catalyst preparation example and an example of acrylonitrile production by propane gas phase catalytic ammoxidation reaction. As long as there is no limitation, it is not limited to these Examples.
The results of the propane ammoxidation reaction were evaluated based on the results of analysis of the reaction gas, using the propane conversion and acrylonitrile selectivity defined by the following equations as indicators.
Propane conversion (%) = (moles of propane reacted) / (moles of propane fed) × 100
Acrylonitrile selectivity (%) = (number of moles of acrylonitrile produced) / (number of moles of reacted propane) × 100
[0031]
(Preparation of niobium-containing liquid)
According to Japanese Patent Laid-Open No. 11-253801, a niobium-containing liquid was prepared by the following method. To 5423 g of water, 782.3 g of niobic acid containing 80.2% by weight as Nb ₂ O ₅ and 3125 g of oxalic acid dihydrate [H ₂ C ₂ O ₄ .2H ₂ O] were mixed. The molar ratio of the charged oxalic acid / niobium is 5.25, and the charged niobium concentration is 0.506 (mol-Nb / Kg-solution). This mixed solution was heated and stirred at 95 ° C. for 1 hour to obtain an aqueous solution in which niobium was dissolved. The aqueous solution was allowed to stand and ice-cooled, and then the solid was separated by suction filtration to obtain a uniform niobium-containing liquid. The niobium-containing liquid had an oxalic acid / niobium molar ratio of 2.395 according to the following analysis.
10 g of this niobium-containing solution was precisely weighed in a crucible, dried overnight at 95 ° C., and then heat-treated at 600 ° C. for 1 hour to obtain 0.848 g of Nb ₂ O ₅ . From this result, the niobium concentration was 0.638 (mol-Nb / Kg-solution).
[0032]
3 g of this niobium-containing solution was precisely weighed into a 300 ml glass beaker, 200 ml of hot water at about 80 ° C. was added, and then 10 ml of 1: 1 sulfuric acid was added. The obtained solution was titrated with 1 / 4N KMnO ₄ under stirring while maintaining the liquid temperature at 70 ° C. on a hot stirrer. The end point was a point where a faint pale pink color by KMnO ₄ lasted for about 30 seconds or more. The concentration of oxalic acid was 1.525 (mol-oxalic acid / Kg) as a result of calculation according to the following formula from titration.
2KMnO ₄ + 3H ₂ SO ₄ + 5H ₂ C ₂ O ₄ → K ₂ SO ₄ + 2MnSO ₄ + 10CO ₂ + 8H ₂ O
The obtained niobium-containing liquid was used as a niobium raw material for the following catalyst preparation without adjusting the molar ratio of oxalic acid / niobium.
[0033]
[Example 1]
(Preparation of catalyst)
An oxide catalyst having a charging composition formula of Mo ₁ V _0.22 Nb _0.10 Sb _0.27 O _n /45.0 wt% -SiO ₂ was produced as follows.
To 2353 g of water, 448.3 g of ammonium heptamolybdate [(NH ₄ ) ₆ Mo ₇ O ₂₄ · 4H ₂ O], 65.36 g of ammonium metavanadate [NH ₄ VO ₃ ], antimony trioxide [Sb ₂ O ₃ ] Was added, and nitrogen gas was circulated in the container, followed by heating at 90 ° C. for 2 hours and 30 minutes with stirring to obtain a mixed solution A-1.
[0034]
22.21 g of antimony trioxide [Sb ₂ O ₃ ] was added to 398.0 g of the niobium-containing liquid (B ₀ ), and 92.12 g of hydrogen peroxide containing 30 wt% as H ₂ O ₂ was added while cooling with ice. A small amount was added and stirred and mixed at room temperature for 1 hour to prepare a mixed solution B-1.
After the obtained solution A-1 was cooled to 70 ° C., 1471 g of silica sol containing 30.6 wt% as SiO ₂ was added, and 90.68 g of hydrogen peroxide containing 30 wt% as H ₂ O ₂ was further added. And stirring was continued at 47 ° C. for 1 hour. Next, the mixed solution B-1 was added and stirring was continued for 20 minutes as it was to obtain a raw material preparation solution.
[0035]
The obtained raw material mixture was supplied to a centrifugal spray dryer and dried without stopping stirring to obtain a fine spherical dry powder. The dryer inlet temperature was 210 ° C and the outlet temperature was 120 ° C.
480 g of the obtained dry powder was filled in a SUS calcining tube having a diameter of 3 inches, and calcined at 640 ° C. for 2 hours while rotating the tube under a nitrogen gas flow of 5.0 NL / min to obtain a catalyst.
[0036]
(Propane ammoxidation reaction)
45 g of the catalyst prepared in a Vycor glass fluidized bed reaction tube having an inner diameter of 25 mm was charged, and propane: ammonia: oxygen: helium = 1: 0.6: 1.5 under a reaction temperature of 440 ° C. and a normal pressure of the reaction. : A mixed gas having a molar ratio of 5.6 was supplied at a contact time of 3.0 (sec · g / cc). The obtained reaction results were a propane conversion of 51.0 mol% and an AN selectivity of 66.9 mol%.
[0037]
[Example 2]
(Preparation of catalyst)
An oxide catalyst having a charging composition formula of Mo ₁ V _0.22 Nb _0.11 Sb _0.28 O _n /45.0 wt% -SiO ₂ was produced as follows.
Stirring for the raw material preparation liquid obtained in Example 1 was stopped for 3 minutes, but no gelation of the raw material preparation liquid occurred and there was no clogging in the piping, so stirring was resumed and continued stirring for 10 minutes. , Dried in the same manner as in Example 1, and then fired. Inhomogeneous component composition could be suppressed.
[0038]
(Propane ammoxidation reaction)
An ammoxidation reaction was carried out in the same manner as in Example 1. The obtained reaction results were a propane conversion of 50.5 mol% and an AN selectivity of 66.5 mol%. A large amount of catalyst with little deterioration in catalyst performance could be produced with good reproducibility.
[0039]
[Comparative Example 1]
(Preparation of catalyst)
An oxide catalyst having a charging composition formula of Mo ₁ V _0.22 Nb _0.11 Sb _0.28 O _n /45.0 wt% -SiO ₂ was produced as follows.
When stirring for the raw material preparation liquid obtained in Example 1 was stopped for 90 minutes, the raw material preparation liquid gelled and lost fluidity, causing clogging in the pipe, but vigorously stirring the obtained gel substance. A fluid slurry was prepared in the same manner as in Example 1 except that the slurry was dried in the same manner as in Example 1 and then fired. It was difficult to suppress non-uniform component composition.
[0040]
(Propane ammoxidation reaction)
An ammoxidation reaction was carried out in the same manner as in Example 1. The obtained reaction results were a propane conversion of 45.1 mol% and an AN selectivity of 61.2 mol%. The catalyst performance decreased, and it was difficult to produce a large amount of catalyst with good reproducibility.
[0041]
【The invention's effect】
The method of the present invention and the catalyst thereof are a novel oxide catalyst production method and catalyst used for the production of an unsaturated acid or an unsaturated nitrile, which suppresses the heterogeneity of the component composition due to gelation and improves the catalyst performance. It was possible to produce a large amount of a catalyst with little deterioration with high reproducibility.

Claims (7)

A method of manufacturing an oxide catalyst for use in propane or isobutane in the vapor phase catalytic oxidation reaction or vapor-phase catalytic ammoxidation reaction, (I) the raw material preparation step, (II) drying process consists (III) firing step, ( in I) raw material preparation step, the catalyst component is not a niobium hydrogen peroxide / niobium molar ratio of 0. mixing the niobium mixture containing 5-20, without Hitakara stirring blade in raw material mixture in the raw material A method for producing an oxide catalyst, characterized in that the non-stirring time during which the preparation liquid is not stirred is within one hour. 2. The method for producing an oxide catalyst according to claim 1, wherein the non-stirring time for the raw material preparation liquid is set to 20 minutes or less. The method for producing an oxide catalyst according to claim 1 or 2 , wherein the oxide catalyst is represented by the following general composition formula (1):
_{Mo 1 V a Nb b X c} O n (1)
(In the formula, component X is at least one element selected from tellurium or antimony, a, b, c, and n represent an atomic ratio per Mo atom, and a is 0.01 ≦ a ≦ 1, b. Is 0.01 ≦ b ≦ 1, c is 0.01 ≦ c ≦ 1, and n is a number determined by the valence of the constituent metals.) The said component X is antimony, The manufacturing method of the oxide catalyst of any one of Claims 1-3 characterized by the above-mentioned. Material of the niobium comprises a compound of a dicarboxylic acid and niobium, according to any one of claims 1 to 4, wherein the molar ratio of the dicarboxylic acid / niobium is niobium-containing liquid 1-4 A method for producing an oxide catalyst. The oxide catalyst is composed of a catalyst constituent element oxide represented by the general composition formula (1) and a silica supporting the catalyst, and the content ratio of the silica is the catalyst constituent element oxide. total weight of the silica to producing the oxide catalyst according to any one of claims 1 to 5, characterized in that it is supported on 20-60 wt.% of the silica in terms of SiO _2. How the method according to any one of claims 1 to 6 to produce an oxide catalyst, by contacting the propane or isobutane to the obtained oxide catalyst, to produce the corresponding unsaturated acid or unsaturated nitrile .