JP2003205237A - Oxidation or ammoxidation catalyst and method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel catalyst having enhanced selectivity of a target substance for manufacturing an unsaturated acid or unsaturated nitrile by the vapor phase catalytic oxidation or ammoxidation of propane or isobutane. <P>SOLUTION: The catalyst is an oxide having a component composition expressed by general formula (1) and the content of metal element Z (where, Z expresses at least a kind of an element selected from copper, solver and tantalum) is ≤1000 ppm by wt. Mo<SB>1</SB>V<SB>a</SB>Nb<SB>b</SB>X<SB>c</SB>O<SB>n</SB>(1). In formula (1), X expresses at least one kind of an element selected from tellurium and antimony, each of (a), (b), (c) and (n) expresses an atomic ratio per one atom of Mo, (a) is 0.01≤a≤1, (b) is 0.01≤b≤1, (c) is 0.01≤c≤1 and (n) is determined on the basis of the valencies and the composition of constitutional metal. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an oxide catalyst used in a gas phase catalytic oxidation or a gas phase catalytic ammoxidation reaction of propane or isobutane, and a method for producing an unsaturated acid or an unsaturated nitrile using the oxide catalyst. .

[0002]

2. Description of the Related Art Conventionally, a method for producing a corresponding unsaturated carboxylic acid or unsaturated nitrile by subjecting propylene or isobutylene to vapor phase catalytic oxidation or vapor phase ammoxidation is well known. In place of the above, a method of producing a corresponding unsaturated carboxylic acid or unsaturated nitrile by vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation of propane or isobutane has been noted, and various catalysts have been proposed.

For example, Mo-V-Nb- (Te / Sb)
An oxide catalyst containing a is disclosed in JP-A-5-148212.
JP-A-7-232071, JP-A-8-14140
1, JP-A-9-157241, JP-A-10-157241.
-330343, JP-A-10-28862, JP-A-11-42434, and JP-A-11-43.
314, JP-A-11-226408, JP-A-10-57479, and JP-A-2000-70714.
JP-A-2000-143244, JP-A-20
No. 01-58827 and the like are disclosed.

Further, oxide catalysts for the production of acrylic acid containing Mo-V-Sb are disclosed in JP-A-2000-354765, JP-A-2000-317309, and JP-A-2000.
-254449, JP2000-256257, JP2000-246108, JP200
0-51693, JP-A-11-285636, JP-A-11-285637, and JP-A-10-2.
It is disclosed in Japanese Patent No. 30164, Japanese Patent Laid-Open No. 2001-70788, and the like.

[0005]

Generally, desired catalyst performance is exhibited by setting the component composition ratio to an appropriate value, optimizing the production method, and the like. However, even if the component composition of the catalyst and the manufacturing method are optimized, the excellent performance originally possessed by the catalyst cannot be often expressed due to the inclusion of a slight amount of impurity element.

[0006] In particular, when producing a catalyst on an industrial scale, it is necessary to produce a large amount of a catalyst having excellent reproducibility and excellent performance. Performance may decrease due to factors that have not occurred in manufacturing using small equipment, such as components to be eluted and components to be mixed in due to wear of equipment members. Therefore, it has been earnestly desired to develop a catalyst in which those impurity components are specified and the impurity concentration is reduced to a content that does not cause performance deterioration.

Therefore, a first object of the present invention is to provide a novel oxide catalyst having a low impurity concentration and used for the production of unsaturated acid or unsaturated nitrile, which has a high selectivity of the objective substance, and a production method thereof. That is. A second object is a method for producing a corresponding unsaturated acid or unsaturated nitrile by subjecting propane or isobutane to a gas phase catalytic oxidation or a gas phase catalytic ammoxidation reaction using the oxide catalyst obtained by the above production method. Is to provide.

[0008]

DISCLOSURE OF THE INVENTION The inventors of the present invention have earnestly studied oxide catalysts used in the vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation of propane or isobutane, and as a result, molybdenum, vanadium, niobium, tellurium and / or Further, they have found that the above problems can be solved by setting the weight fraction of impurity elements (copper, silver, tantalum) in the catalyst solid content containing antimony to 1000 ppm or less, and have completed the present invention. That is, the present invention comprises the following aspects.

[1] An oxide catalyst having a component composition represented by the following general composition formula (1), which is used in a gas-phase catalytic oxidation reaction or a gas-phase catalytic ammoxidation reaction of propane or isobutane, wherein Metal element Z (Z is copper, silver,
An oxide catalyst, characterized in that the proportion of at least one element selected from tantalum) is 1000 ppm or less in terms of weight fraction. During _{Mo 1 V a Nb b X c} O n (1) ( Formula (1), component X is at least one element selected from tellurium and antimony, a, b, c, d and n are per Mo1 atoms Represents an atomic ratio, and a is 0.01 ≦
a ≦ 1, b is 0.01 ≦ b ≦ 1, c is 0.01 ≦ c ≦
1 and n are numbers determined by the valence and composition of the constituent metals. )

[2] The oxide catalyst according to the above [1], wherein Z is copper.

[3] The above Z ratio is 100 by weight.
The oxide catalyst according to any one of the above [1] and [2], which is at most ppm.

[4] The oxide catalyst according to any one of the above [1] to [3], wherein the component X is antimony.

[5] The niobium raw material of the above oxide catalyst is
Including dicarboxylic acid and niobium compounds, dicarboxylic acid /
The oxide catalyst according to any one of the above [1] to [4], which is a niobium-containing liquid having a niobium molar ratio of 1 to 4.

[6] The oxide catalyst comprises a catalyst constituent element oxide represented by the general composition formula (1) and silica carrying the catalyst constituent element oxide, and the catalyst constituent element oxide is Based on the total weight of the catalyst constituent element oxide and silica,
The oxide catalyst according to any one of the above [1] to [5], which is supported on silica in an amount of 20 to 60% by weight in terms of SiO ₂ .

[7] A method for producing an oxide catalyst according to the above [1] to [6], which comprises (I) a raw material mixing step and (II)
A method for producing an oxide catalyst, which comprises a drying step and a calcination step (III), wherein a raw material substantially free of the metal element Z is used in the raw material blending step.

[8] In the equipment used in the raw material blending step and the drying step, a material which does not substantially contain the metal element Z is used as the liquid contact portion and / or the rotating member material. ] The manufacturing method of the oxide catalyst as described in.

[9] In the above firing step, the metal element Z is substantially used as the material of the firing tube and / or the material of the rotating member.
The method for producing an oxide catalyst according to any one of the above [7] or [8], characterized in that a material not containing is used.

[10] In the above-mentioned raw material mixing step, the raw material of niobium of the oxide catalyst is a niobium-containing liquid containing a compound of dicarboxylic acid and niobium and having a dicarboxylic acid / niobium molar ratio of 1 to 4. The above [7] to [9]
5. The method for producing an oxide catalyst according to any one of 1. [11] In producing a corresponding unsaturated acid or unsaturated nitrile by subjecting propane or isobutane to a gas phase catalytic oxidation reaction or a gas phase catalytic ammoxidation reaction, the method according to any one of the above [1] to [6] A method for producing an unsaturated acid or an unsaturated nitrile, which comprises using an oxide catalyst.

The present invention will be described in detail below. The catalyst 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 formula (1), component X represents at least one element selected from tellurium or antimony, a, b, c and n are atoms per Mo1 atoms Represents a ratio, and a is 0.01 ≦
a ≦ 1, b is 0.01 ≦ b ≦ 1, c is 0.01 ≦ c ≦
1 and n are numbers determined by the valence and composition of the constituent metals. The atomic ratios a to c per Mo atom are 0.1 to 0.4, 0.01 to 0.2, and
0.1 to 0.5 is preferable. As the component X, antimony is more preferable.

In the oxide catalyst of the present invention, the weight ratio of the metal element Z (at least one element selected from copper, silver and tantalum) to the catalyst solid content is 1000 p.
It is pm or less, preferably 100 ppm or less.

That is, among the elements contained as impurities in the oxide catalyst, copper, silver and tantalum have a great influence on the oxide catalyst of the present invention, so at least one of these elements is 1000 ppm or less, preferably Is 100 ppm or less. Further, among copper, silver and tantalum, copper significantly lowers the performance of the oxide catalyst, so that the copper content is 1000 ppm or less, preferably 100 ppm.
The following is more preferable. Furthermore, it is more preferable that each of copper, silver, and tantalum is 1000 ppm or less, and even more preferable that each of them is 100 ppm or less.

It is preferable that the amount of these elements is as small as possible, and there is no limit to the lower limit. More preferably, atomic absorption method, IC, which is generally carried out as a metal analysis method
It is below the detection limit in P analysis method, fluorescent X-ray analysis method and the like. Here, the catalyst solid content represents the solid content remaining when the raw material preparation liquid is dried and then calcined, and contains the catalytically active component and the carrier component.

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 high mechanical strength and 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 carrier is preferably 20 to 60% by weight, and more preferably 25 to 60% by weight in terms of SiO ₂ , with respect to the total weight of the silica-supported oxide catalyst composed of the oxide of the catalyst constituent elements and the silica carrier. 55% by weight.

The oxide catalyst of the present invention can be prepared by the following general method. That is,
(I) Raw material mixing step, (II) Step of drying raw material mixed solution obtained in step (I) to obtain catalyst precursor, (III) Step of firing catalyst precursor obtained in step (II) It can be manufactured through three steps.

The formulation in the method for producing an oxide catalyst of the present invention is to dissolve or disperse the raw materials of the catalyst constituent elements in an aqueous solvent. The raw material is used in the step (I). The raw material used in the preparation method of the present invention is not particularly limited, but a material that does not substantially contain the metal element Z, which is a component that deteriorates catalyst performance, is used. Further, it is preferable that the raw material of the carrier component and the solvent such as water do not substantially contain a component that deteriorates the catalyst performance. For example, the following compounds can be used as the raw material.

The raw material for Mo can be used ammonium heptamolybdate _{[(NH 4) 6 Mo 7 O} 24 · 4H 2 O ] favorably. As a raw material of V, ammonium metavanadate [NH ₄ VO ₃ ] can be preferably used.

As the raw material of Nb, niobic acid, an inorganic acid salt of niobium and an organic acid salt of niobium can be used.
Niobate is particularly preferable. Niobate is represented by Nb ₂ O ₅ .nH ₂ O and is also called niobium hydroxide or niobium oxide hydrate. Further, the molar ratio of dicarboxylic acid / niobium is 1 to 4
It is preferable to use it as the Nb raw material liquid. By adjusting the molar ratio of dicarboxylic acid / niobium to the above value, the redox state of the metal constituting the catalyst can be adjusted and the catalyst performance can be made particularly excellent. Further, the dicarboxylic acid is preferably oxalic acid.

As a raw material for Sb, diantimony trioxide [Sb ₂ O ₃ ] is preferable. Further, in order to improve the dissolution rate of Sb in the aqueous solvent, it is preferable to use Sb ₂ O ₃ having an average particle size of 1 μm or less. As a raw material of Te, telluric acid [H ₆ TeO ₆ ] is preferable. The silica raw material is preferably silica sol.

Hereinafter, a preferred catalyst preparation example according to the production method of the present invention comprising steps (I) to (III) will be described. (Step I: Raw Material Mixing Step) Using the raw materials described above, a raw material mixed solution is obtained. An example of preparation of the raw material mixed liquid is shown below. Ammonium heptamolybdate, ammonium metavanadate, and diantimony 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 mixed solution (B ₀ ). As the mixed solution (B ₀ ), a niobium-containing solution obtained by the method taught in JP-A No. 11-253801 can be used. Further, hydrogen peroxide and diantimony trioxide are added to at least a part of the mixed solution (B ₀ ) to prepare a mixed solution (B). At this time, H ₂ O ₂ / Nb (molar ratio) is 0.5 to 20, especially 1
-10 is preferable, and Sb / Nb (molar ratio) is 0-5, especially 0.01-2 is preferable. Oxalic acid may be added to the mixed solution (B).

Next, a mixed solution is prepared according to the desired composition.
(A), mixed solution (B), mixed solution (B ₀) Is preferably mixed
A raw material preparation liquid is obtained. The ammoxidation catalyst of the present invention is
In the case of Rica supported catalyst, the raw material should be mixed to contain silica sol.
The liquid is prepared. Silica sol can be added appropriately
It When antimony is used, the mixed solution (A),
Alternatively, the solution containing the components of the mixed solution (A) being prepared may be
It is preferred to add hydrogen oxide. At this time, H_TwoO_Two
/ Sb (molar ratio) is preferably 0.01 to 5, particularly preferably 1 to 3.
Good Also, at this time, at 30 ° C to 70 ° C for 30 minutes to 2:00
It is preferable to continue stirring for a while.

In the above-mentioned raw material mixing step, it goes without saying that the material used for the wetted part and / or the rotary part of the equipment to be used is selected so as not to elute the constituent components of the material or to mix different components due to abrasion. However, it is particularly preferable to use a material that does not cause the mixing of the metal element Z. The wetted part referred to in the production method of the present invention represents a facility or a region on the facility that is constantly in contact with or may be in contact with a liquid substance containing a raw material, and only a raw material mixing tank or a liquid feeding pipe However, the invention is not limited to this, and includes a stirring blade, a heating coil, a cooling coil, a liquid substance circulating portion of a liquid feed pump, and the like. In addition, the rotating part in the raw material mixing step means, in a stirrer, a stirrer bearing, a liquid substance distribution part of a liquid feed pump, etc., equipment or facilities in which a substance generated by rotational wear may be mixed in the liquid substance containing the raw material. Represents the area above. The material referred to in the production method of the present invention is a material that constitutes equipment used in the catalyst production process. As a material used for the liquid contact part and / or the rotating part in the raw material mixing step, for example, SUS304
Stainless steel such as can be preferably used.

(Step II: Drying Step) The raw material preparation liquid obtained in the step (I) is dried by a spray drying method to obtain a dry powder. For the atomization in the spray drying method, a centrifugal system, a two-fluid nozzle system or a high pressure nozzle system can be adopted. As the dry 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. In addition, it is preferable to select the material used for the liquid contact part and / or the rotating part in the catalyst manufacturing equipment in the drying step, in the same manner as in the raw material mixing step.

(Step III: Firing Step) In step (III),
The oxide powder is obtained by calcining the dry powder obtained in step (II), that is, the drying step. Firing is nitrogen gas,
Under an inert gas atmosphere containing substantially no oxygen such as argon gas or helium gas, preferably while flowing an inert gas, 500 to 800 ° C., preferably 600 to
Carry out at 700 ° C. The firing time is 0.5 to 20 hours, preferably 1 to 8 hours. Firing can be performed using a rotary furnace, a tunnel furnace, a tubular furnace, a fluidized firing furnace, or the like, but it is preferable to use a rotary furnace in mass firing. Firing can be repeated. Before the firing step, the dry powder is heated to 200 to 400 ° C. in an air atmosphere or under air flow, 1
It can also be pre-baked in ~ 5 hours.

Firing tube and / or used in the firing step
Alternatively, as the material of the rotating portion, the metal element Z is not substantially contained, a substance generated by abrasion is not mixed into the catalyst, and further, it is different in the catalyst due to a solid-phase reaction that can occur by contact with the catalyst at high temperature. It is preferable to use a material that does not contain components. For example, stainless steel such as SUS304 can be used. Here, the rotating part in the firing step refers to a part in the rotary furnace where substances generated by rotational wear may be mixed into the catalyst.

Propane or isobutane is subjected to a gas phase catalytic oxidation or a gas phase catalytic ammoxidation reaction in the presence of the oxide catalyst produced according to the above steps (I) to (III),
The corresponding unsaturated acid or unsaturated nitrile is prepared.

The propane or isobutane and ammonia feedstocks do not necessarily have to be of 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, steam, nitrogen or the like may be supplied as a diluent gas.

The vapor 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. Reaction temperature is 300 ℃
-500 degreeC, Preferably it is 350 degreeC-450 degreeC. The reaction pressure is 5 × 10 ^{4 to} 5 × 10 ⁵ Pa, preferably 1 × 1.
It is from 0 ^{5 to} 3 × 10 ⁵ Pa. Contact time is 0.1-10
(S · g / ml), preferably 0.5 to 5 (s · g / m)
l). In the present invention, the contact time is determined by the following equation. The contact time is as shown in the following formula. Contact time (s · g / ml) = (W / F) × 273 / (2
73 + T) where W = charged catalyst amount (g) F = raw material mixed gas flow rate (Nml / s) in standard state (0 ° C., 1.013 × 10 ⁵ Pa) T = reaction temperature (° C.)

The vapor 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 fed to the reaction to propane or isobutane is 0.3 to 1.5, preferably 0.8 to 1.0. The reaction temperature is 350 ° C to 500 ° C, preferably 380
C to 470C. 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 (s · g / ml), preferably 0.5 to 5 (s · g / ml). As a reaction system, a conventional system such as a fixed bed, a fluidized bed or a moving bed can be adopted, but a fluidized bed reactor which can easily remove reaction heat is preferable. Further, the reaction of the present invention may be a single flow type or a recycle type.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the oxide catalyst of the present invention will be described with reference to Examples of preparation of the catalyst and production of acrylonitrile by gas phase catalytic ammoxidation reaction of propane. The present invention is not limited to these examples as long as it is not changed. Further, in preparing the catalysts of the following Examples and Comparative Examples, a liquid-feeding pump for slurry, a silicone tube containing no metal element was used for the liquid substance circulating portion in the liquid-feeding pump, and all other device members were made of SUS. The one manufactured was used.

(Evaluation Method of Reaction Results) The results of the propane ammoxidation reaction were evaluated based on the results of analysis of the reaction gas, using the propane conversion rate and acrylonitrile selectivity defined by the following formulas as indexes. Propane conversion rate (%) = (number of moles of reacted propane)
/ (Mol number of propane supplied) × 100 acrylonitrile selectivity (%) = (mol number of acrylonitrile produced) / (mol number of reacted propane) × 1
00

(Preparation of Niobium Raw Material Liquid) JP-A-11-25
A niobium raw material liquid was prepared by the following method according to Japanese Patent No. 3801. First, 5640 g of water was added as Nb ₂ O ₅ at 80.
795.1 g of niobic acid containing 2% by weight and 3120 g of oxalic acid dihydrate [H ₂ C ₂ O ₄ .2H ₂ O] were mixed.
The charged oxalic acid / niobium molar ratio was 5.24, and the charged niobium concentration was 0.502 mol (Nb) / kg (liquid). 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 cooled with ice, and then the solid was filtered off by suction filtration to obtain a uniform niobium-containing liquid. The oxalic acid / niobium molar ratio of this niobium-containing liquid was 2.395 according to the following analysis.

10 g of this niobium-containing liquid was precisely weighed in a crucible, dried overnight at 95 ° C., and then heat-treated at 600 ° C. for 1 hour,
0.849 g of Nb ₂ O ₅ was obtained. From this result, the niobium concentration was 0.639 mol (Nb) / kg (liquid). Next, separately weigh 3 g of this niobium-containing liquid into a 300 ml glass beaker, add 200 ml of hot water at about 80 ° C.,
Subsequently, 10 ml of 1: 1 sulfuric acid was added. While stirring the obtained solution on a hot stirrer at a liquid temperature of 70 ° C.,
Titration was performed with 1/4 normal KMnO ₄ . The end point was a point where a faint light pink color due to KMnO ₄ continued for about 30 seconds or longer.
The concentration of oxalic acid was 1.530 mol / kg as a result of calculation from the titration amount according to the following formula. 2KMnO ₄ + 3H ₂ SO ₄ + 5H ₂ C ₂ O ₄ → K ₂ SO ₄ +2
MnSO ₄ + 10CO ₂ + 8H ₂ O The obtained niobium-containing liquid was a niobium raw material liquid (B) for catalyst preparation described below without adjusting the oxalic acid / niobium molar ratio.
₀ ).

[0043]

[Example 1] (Preparation of catalyst) The composition formula was Mo ₁ V _0.21 Nb _0.11 Sb _0.27 O _n / 4.
An oxide catalyst represented by 5.0 wt% -SiO ₂ was manufactured as follows. Water 2
242 g of ammonium heptamolybdate [(N
H ₄₎ a _{6 Mo 7 O 24 · 4H 2} O ] 447.5g, 62.27g of ammonium metavanadate [NH ₄ VO _3], diantimony trioxide [Sb ₂ O _3] was added 77.57G, vessel Nitrogen gas was passed through the mixture and heated at 90 ° C. for 2 hours and 30 minutes with stirring to obtain a mixed solution A-1.

To 436.3 g of the niobium mixed solution (B ₀ ) was added H ₂
Oxygenated water containing 30 wt% as O ₂ was added to 97.
69 g was added, and diantimony trioxide [S
b ₂ O _3] were added 28.50 g, was mixed and stirred at room temperature for 10 minutes, the mixture B-1 was prepared.

After cooling the obtained solution A-1 to 70 ° C., 1471 g of silica sol containing 30.6 wt% as SiO ₂ was added, and further hydrogen peroxide solution 90.90 containing 30 wt% as H ₂ O ₂ . Add 51 g, 1 at 45 ° C
Stirring was continued for hours. Next, the mixed liquid B-1 was added to obtain a raw material preparation liquid. The obtained raw material preparation liquid was supplied to a centrifugal spray dryer and dried 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 firing tube having a diameter of 3 inches (about 7.6 cm) and 5.0 N
Under nitrogen gas flow of L / min, while rotating the tube, 6
The catalyst was obtained by calcining at 40 ° C. for 2 hours. When the composition of the obtained catalyst was analyzed by fluorescent X-ray analysis, the weight content of copper was below the detection limit.

(Propane ammoxidation reaction) Inner diameter 25 m
m of Vycor glass fluidized bed type reaction tube was filled with 45 g of the obtained catalyst, and the reaction temperature was 440 ° C. and the reaction pressure was normal pressure. Propane: ammonia: oxygen: helium = 1: 1.
A mixed gas having a molar ratio of 0.6: 1.5: 5.6 was supplied at a contact time of 3.0 (s · g / ml). The obtained reaction results are shown in Table 1 below.

[0048]

[Example 2] (Preparation of catalyst) The composition formula was Mo ₁ V _0.21 Nb _0.11 Sb _0.27 O _n / 4.
An oxide catalyst represented by 5.0 wt% -SiO ₂ was manufactured as follows. The raw material mixture obtained in Example 1 was added with copper nitrate (Cu (NO ₃ ) ₂
3H ₂ O) (0.075 g) was added, and the mixture was stirred for 10 minutes to obtain an oxide catalyst in the same manner as in Example 1.
The composition of the catalyst after calcination was analyzed by fluorescent X-ray analysis,
The weight content of copper in the catalyst was 19 ppm. Example 1
Table 1 below shows the obtained reaction results for the same propane ammoxidation reaction as described above.

[0049]

[Example 3] (Preparation of catalyst) The composition formula was Mo ₁ V _0.21 Nb _0.11 Sb _0.27 O _n / 4.
An oxide catalyst represented by 5.0 wt% -SiO ₂ was manufactured as follows. The raw material mixture obtained in Example 1 was added with copper nitrate (Cu (NO ₃ ) ₂
(3H ₂ O) was added, and then an oxide catalyst was obtained in the same manner as in Example 1 except that stirring was performed for 10 minutes. The composition of the catalyst after calcination was analyzed by fluorescent X-ray analysis, and as a result, the copper content by weight in the catalyst was 52 ppm. Regarding the same propane ammoxidation reaction as in Example 1, the obtained reaction results are shown in Table 1 below.

[0050]

[Comparative Example 1] (Preparation of catalyst) The composition formula was Mo ₁ V _0.21 Nb _0.11 Sb _0.27 O _n / 4.
An oxide catalyst represented by 5.0 wt% -SiO ₂ was manufactured as follows. The raw material mixture obtained in Example 1 was added with copper nitrate (Cu (NO ₃ ) ₂
(3H ₂ O) was added, and then an oxide catalyst was obtained in the same manner as in Example 1 except that stirring was performed for 10 minutes. The composition of the catalyst after calcination was analyzed by fluorescent X-ray analysis, and as a result, the copper content by weight in the catalyst was 4988 ppm. Regarding the same propane ammoxidation reaction as in Example 1, the obtained reaction results are shown in Table 1 below.

[0051]

[Comparative Example 2] (Preparation of catalyst) The composition formula was Mo ₁ V _0.21 Nb _0.11 Sb _0.27 O _n / 4.
An oxide catalyst represented by 5.0 wt% -SiO ₂ was manufactured as follows. The raw material mixture obtained in Example 1 was added with copper nitrate (Cu (NO ₃ ) ₂
3H ₂ O) (76.3 g) was added and the mixture was stirred for 10 minutes to obtain an oxide catalyst in the same manner as in Example 1. The composition of the catalyst after calcination was analyzed by fluorescent X-ray analysis, and as a result, the copper content by weight in the catalyst was 20025 ppm. Regarding the same propane ammoxidation reaction as in Example 1, the obtained reaction results are shown in Table 1 below.

[0052]

[Example 4] (Preparation of catalyst) The composition formula was Mo ₁ V _0.21 Nb _0.11 Sb _0.27 O _n / 4.
An oxide catalyst represented by 5.0 wt% -SiO ₂ was manufactured as follows. Assuming that copper as an impurity was mixed in in the firing step, 480 g of the dry powder obtained in the same manner as in Example 1 and the copper powder of 0.
014g was mixed and fired. An oxide catalyst was obtained in the same manner as in Example 1 except that the copper powder was mixed. The composition of the catalyst after calcination was analyzed by fluorescent X-ray analysis, and as a result, the copper content by weight in the catalyst was 26 ppm. Regarding the same propane ammoxidation reaction as in Example 1, the obtained reaction results are shown in Table 1 below.

[0053]

[Comparative Example 3] (Preparation of catalyst) The composition formula was Mo ₁ V _0.21 Nb _0.11 Sb _0.27 O _n / 4.
An oxide catalyst represented by 5.0 wt% -SiO ₂ was manufactured as follows. Assuming that copper as an impurity was mixed in in the firing step, 480 g of the dry powder obtained in the same manner as in Example 1 and the copper powder 2.
44 g was mixed and fired. Example 1 except mixing of copper powder
An oxide catalyst was obtained in the same manner as in. Fluorescent X after burning catalyst
As a result of compositional analysis by line analysis, the copper weight content in the catalyst was 5020 ppm. Regarding the same propane ammoxidation reaction as in Example 1, the obtained reaction results are shown in Table 1 below.

[0054]

[Comparative Example 4] (Preparation of catalyst) The composition formula was Mo ₁ V _0.21 Nb _0.11 Sb _0.27 O _n / 4.
An oxide catalyst represented by 5.0 wt% -SiO ₂ was manufactured as follows. Assuming that copper as an impurity was mixed in in the firing step, 480 g of dry powder and copper powder obtained in the same manner as in Example 1 and 9.
90g was mixed and baked. Example 1 except mixing of copper powder
An oxide catalyst was obtained in the same manner as in. Fluorescent X after burning catalyst
As a result of composition analysis by line analysis, the copper content by weight in the catalyst was 20110 ppm. Regarding the same propane ammoxidation reaction as in Example 1, the obtained reaction results are shown in Table 1 below.

[0055]

[Comparative Example 5] (Preparation of catalyst) The composition formula was Mo ₁ V _0.21 Nb _0.11 Sb _0.27 O _n / 4.
An oxide catalyst represented by 5.0 wt% -SiO ₂ was manufactured as follows. Silver carbonate (AgCO ₃ ) 2 was added to the raw material preparation liquid obtained in Example 1.
After adding 6.3 g, an oxide catalyst was obtained in the same manner as in Example 1 except that stirring was performed for 10 minutes. The composition of the catalyst after calcination was analyzed by fluorescent X-ray analysis, and as a result, the copper content by weight in the catalyst was 16100 ppm. Regarding the same propane ammoxidation reaction as in Example 1, the obtained reaction results are shown in Table 1 below.

[0056]

[Table 1]

[0057]

By using the oxide catalyst obtained by the present invention, unsaturated carboxylic acid or unsaturated nitrile can be produced from propane or isobutane with high selectivity. In addition, the production method of the present invention makes it possible to obtain a large amount and reproducibly of an oxide catalyst effective for the vapor phase catalytic oxidation or vapor phase catalytic ammoxidation of propane or isobutane.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4G069 AA03 AA08 BA02B BA27C                       BB06A BB06B BC26A BC26B                       BC54A BC54B BC55A BC55B                       BC59A BC59B BE08A BE08B                       BE08C CB07 CB54 CB55                       DA06 EA01Y EA02Y FB04                       FB05                 4H006 AA02 AC54 BA12 BA13 BA14                       BA30 BA33 BA60 BE30 QN26                 4H039 CA70 CC20 CD10

Claims (11)

[Claims] 1. An oxide catalyst having a component composition represented by the following general composition formula (1), which is used in a vapor-phase catalytic oxidation reaction or a vapor-phase catalytic ammoxidation reaction of propane or isobutane, wherein the metal is based on the solid content of the catalyst. An oxide catalyst, wherein the proportion of the element Z (Z is at least one element selected from copper, silver and tantalum) is 1000 ppm or less in terms of weight fraction. During _{Mo 1 V a Nb b X c} O n (1) ( Formula (1), the component X is at least one element selected from tellurium and antimony, a, b, c, d and n are per Mo1 atoms Represents the atomic ratio of, and a is 0.01 ≦
a ≦ 1, b is 0.01 ≦ b ≦ 1, c is 0.01 ≦ c ≦
1 and n are numbers determined by the valence and composition of the constituent metals. ) 2. The oxide catalyst according to claim 1, wherein Z is copper. 3. The weight ratio of Z is 100 pp.
It is m or less, The oxide catalyst of Claim 1 or 2 characterized by the above-mentioned. 4. The oxide catalyst according to claim 1, wherein the component X is antimony. 5. The niobium raw material of the oxide catalyst contains a compound of dicarboxylic acid and niobium, and is a niobium-containing liquid having a dicarboxylic acid / niobium molar ratio of 1 to 4. The oxide catalyst according to any one of 4 above. 6. The oxide catalyst comprises a catalyst constituent element oxide represented by the general composition formula (1) and silica carrying the catalyst constituent element oxide, wherein the catalyst constituent element oxide is S with respect to the total weight of oxides and silica that constitute the catalyst
The oxide catalyst according to any one of claims 1 to 5, which is supported on silica in an amount of 20 to 60% by weight in terms of iO ₂ . 7. The method for producing an oxide catalyst according to claim 1, comprising (I) a raw material mixing step, (II) a drying step,
(III) A method for producing an oxide catalyst, which comprises a calcination step and uses a raw material that does not substantially contain the metal element Z in the raw material mixing step. 8. In the equipment used in the raw material mixing step and the drying step, a material that does not substantially contain the metal element Z is used as the liquid contact portion and / or the rotating member material. A method for producing the oxide catalyst described. 9. The method according to claim 7, wherein in the firing step, a material that does not substantially contain the metal element Z is used as the material of the firing tube and / or the material of the rotating member.
5. The method for producing an oxide catalyst according to any one of 1. 10. The niobium raw material of the oxide catalyst in the above raw material mixing step is a niobium-containing liquid having a dicarboxylic acid / niobium compound and a dicarboxylic acid / niobium molar ratio of 1 to 4. The method for producing an oxide catalyst according to any one of claims 7 to 9. 11. Producing a corresponding unsaturated acid or unsaturated nitrile by subjecting propane or isobutane to a gas phase catalytic oxidation reaction or a gas phase catalytic ammoxidation reaction,
A method for producing an unsaturated acid or an unsaturated nitrile, which comprises using the oxide catalyst according to any one of claims 1 to 6.