JP2000117103A - Catalyst for oxidation of alkane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst for producing acrylonitrile, acrylic acid, and the like useful as industrial raw materials from alkanes. SOLUTION: This catalyst is a compounded oxide having a general formula; Nba Bib Vc Ze On; for (amm)oxidization of alkanes. In the formula, X stands for one or more elements selected from titanium, iron, and aluminum; Z for tungsten; and a, b, c, d, e, and n can be defined as b=0.1-9; c=0.1-10; d=0-5; e= 05; and n is the number determined by the oxidation valence of other elements in the case a=10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a catalyst used for alkane oxidation, more specifically, a catalyst for producing nitrile from alkane by ammoxidation, a method for producing nitrile from alkane, and aldehyde and / or carboxylic acid from alkane. The present invention relates to a method for producing an acid. Nitriles such as acrylonitrile and methacrylonitrile are industrially important as intermediates for fibers, synthetic resins and synthetic rubbers, and carboxylic acids such as acrylic acid and methacrylic acid are used for various synthetic resins, paints and plasticizers. It is industrially important as a raw material.

[0002]

2. Description of the Related Art As a method for producing a nitrile, a so-called ammoxidation method in which an alkene is subjected to a high-temperature catalytic reaction of ammonia and oxygen in the presence of a catalyst in the presence of a catalyst is known as a general method. On the other hand, a method for producing a nitrile from a less expensive alkane as a starting material has been extensively studied, and various catalysts have been reported.

As a catalyst for nitrile production by a gas phase catalytic oxidation reaction of alkane and ammonia, a catalyst containing molybdenum or vanadium as an essential main element, Mo-Bi-
P-based catalyst (JP-A-48-16887), V-Sb
Catalysts obtained by mechanically mixing -W-based oxides and Mo-Bi-Ce-W-based oxides (JP-A-64-38051), Mo-Ag-Bi-V-based catalysts (JP-A-Heisei 3 -589
No. 61), a Mo-V-Sn-Bi-P catalyst (JP-A-4-247060), a Mo-Cr-Te catalyst (U.S. Pat. No. 5,171,876), Mo and Mn, Co
Composite metal oxide catalyst comprising an element such as
No. 94347), Mo-V-Te based catalysts (Japanese Unexamined Patent Application Publication No.
-257, JP-A-5-148212, JP-A-5-208136, JP-A-6-279351
JP-A-6-287146, JP-A-7-108
No. 101), a Mo-V-Sb-based catalyst (Japanese Patent Application Laid-Open
No. 157241), a Mo-Cr-Bi-based catalyst (Japanese Patent Application Laid-Open No. 7-215925), a Mo-Te-based catalyst (Japanese Patent Application Laid-Open No. 7-215926), and a V-Sb-based catalyst (Japanese Patent Application Laid-Open No. 47-33783). JP, JP-B-50-23016, JP-A-1-268668, JP-A-2-18
No. 0637), V-Sb-U-Ni catalyst (Japanese Patent Publication No. 47-14371), V-Sb-WP catalyst (JP-A-2-95439), VW-Te catalyst (JP-A-6-228073), Mo-W-Bi catalysts (JP-A-9-276696), Mo-Sb-Cr catalysts (JP-A-10-43586) and the like. Also,
Catalyst containing Bi and V as essential elements
No. 5545) is also known. In addition, Cr-Sb-W-based catalysts that do not require molybdenum and vanadium (Japanese Patent Application Laid-Open No. 7-157 and 461) and Nb-Sb-based catalysts (Japanese Patent Application Laid-Open No. 10-1465) are disclosed.

[0004] As an example of a report of producing acrolein and / or acrylic acid in a single step by subjecting propane to a gas phase catalytic oxidation reaction, Mo-Sb-PO catalysts (European Patent No. 0010902), V- P-Te-O
Based catalyst (Journal of Catalyst,
vol. 101, p389 (1986)), Bi-Mo
-O-based catalyst and / or VP-Te-O-based catalyst (JP-A-3-170445), Mo-Sb-VX-
O-based catalyst (JP-A-9-316023, 10-1
No. 18491, No. 10-120617, No. 1
0-137585), P-Mo-VWXO
-Based catalyst (JP-A-10-045643) Mo-Sb
-V-X-O based catalyst (JP-A-10-045664) Mo-V-Te (Sb) -X-O (JP-A-10-0)
No. 57813) is known. On the other hand, as an example of a report of producing methacrylic acid in one step by subjecting isobutane to a gas phase catalytic oxidation reaction, a P-Mo-O-based catalyst (JP-A-63-145249) is known.

[0005]

However, in these systems, it is necessary to use a catalyst having a strong oxidizing power in order to activate alkanes having low reactivity or to improve the yield of nitrile, aldehyde and / or carboxylic acid. Attempts have been made to supply water to the reactor. The use of a catalyst with a strong oxidizing power increases the combustion of ammonia, which is a raw material.Therefore, there is a problem that an excessive amount of ammonia must be supplied as a raw material compared to the amount of ammonia originally required for the reaction. Also, supplying water to the reactor is not advantageous because of the increase in variable costs of the supply system. Also,
In a catalyst system containing easily volatilizable elements such as molybdenum and tellurium, these elements volatilize alone or in the form of a compound during the reaction, and there is a problem such as a decrease in catalytic performance over time. .

An ammoxidation catalyst for alkanes containing bismuth and vanadium as essential elements as a combination of elements that are difficult to volatilize is described in JP-A-63-295545. In this publication, a number of examples are described, but a catalyst composed of a composite oxide having a composition ratio similar to that of the catalyst of the present invention and a completely different composition ratio is described as Example 38. The reaction conditions in this example were such that ammonia was supplied in an amount of twice as much as that of propane in excess of ammonia, and water that was not directly required for the reaction was supplied to the reactor. However, it is not advantageous reaction conditions in general, and further improvement in catalyst performance is required.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above-mentioned problems, and as a result, it has been found that, when an excessive amount of ammonia is supplied or water is not supplied to the reactor, molybdenum or tellurium is not supplied. By using a catalyst containing niobium, bismuth, and vanadium as the main components, which do not contain easily volatilizable elements, and containing these in a specific ratio, nitrile or aldehyde and / or carboxylic acid can be produced from alkane in good yield. I found it.

That is, the gist of the present invention is that the following general formula (1)
Alkanes consisting of a complex oxide represented by
Exists in a catalyst for oxidation. _{Nb a Bi b V c X d} Z e O n (1) ( wherein, X represents one or more elements selected from the group consisting of titanium, iron and aluminum, Z is showed chromium or tungsten, a = 10, b = 0.1
-9, c = 0.1-10, d = 0-5, e = 0-5, n
Represents 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. The composite oxide used in the catalyst of the present invention does not contain an element such as molybdenum or tellurium which is easy to volatilize as a main component, niobium or bismuth as a skeletal component, and also contains vanadium at the same time. It is represented by the general formula (1). Nb _a of _{Bi b V c X d Z e} O n (1) formula, X is represents one or more elements selected from the group consisting of titanium, iron and aluminum, preferably, shows a titanium. Z represents chromium or tungsten. However,
Does not contain chromium and tungsten at the same time. Z preferably represents tungsten.

In the equation, when a = 10, each coefficient is b
Is 0.1 to 9, preferably 0.1 to 7, particularly preferably 0.2 to 5, c is 0.1 to 10, preferably 0.1 to
3, particularly preferably 0.3-2, d is 0-5, preferably 0-3, particularly preferably 0-2, e is 0-5, preferably 0.1-4, particularly preferably 0.2. 3, n are numbers determined by the oxidation state of other elements. Although the composite oxide used in the present invention is not a mixture of single oxides, all crystals need not have the same composition ratio, and the average composition ratio may be within this range.

In the catalyst comprising the composite oxide of the present invention, bismuth and niobium are the main components, and it is known that the composite oxide containing these forms various structures. For example, the defect pyrochlore structure represented by the general formula of Bi _1.34 NbCrO _{6 is one} such example.
society of Japan, vol. 50 (10), 2638-2642 (1977). In this structure, the total content of niobium and chromium is constant, and the ratio of niobium, the highest valence of which is pentavalent, to chromium, which has the highest valence of 3, is bismuth, whose stable valence is trivalent. The content in the defect pyrochlore structure is determined by the charge balance in the crystal.

In the present invention, the relationship between the catalytic performance and the structure / composition of the composite oxide is not clear, but the composition ratio of each element is determined based on the above-mentioned concept based on niobium, vanadium, X and Z. If the total content is constant, it is presumed that the bismuth content can be determined from the highest or stable valence and the content of each of these elements.

The raw material of the composite metal oxide constituting the catalyst of the present invention is not particularly limited as long as it is a substance containing niobium. Preferably, niobium ammonium oxalate, niobium pentoxide, niobate, Niobium pentachloride, niobium metal solubilized with a suitable reagent, and the like are used, and particularly preferred is niobium ammonium oxalate.

The bismuth raw material is not particularly limited as long as it is a substance containing bismuth. Preferably, bismuth nitrate, bismuth trioxide, bismuth hydroxide, bismuth trichloride, bismuth acetate, bismuth nitrate oxide, and metal bismuth are suitably used. Those solubilized with a reagent are used, and bismuth nitrate is particularly preferably used.

[0015] The vanadium raw material is not particularly limited as long as it is a substance containing vanadium. Preferably, a material obtained by solubilizing ammonium metavanadate, vanadium pentoxide, vanadium oxychloride, metal vanadium with a suitable reagent, or the like is used. Particularly preferably, ammonium metavanadate is used.

The raw material of one or more elements selected from the group consisting of titanium, iron and aluminum is not particularly limited as long as it is a substance containing these elements. And those obtained by solubilizing metals of these elements with an appropriate reagent can be used. Compounds containing these elements usually include nitrates, sulfates, carboxylate salts, ammonium carboxylate salts, ammonium halide salts, oxides, halides, hydroxides, hydrated oxides, hydrogen acid, acetylacetate. Nartate, alkoxide and the like can be used, but nitrate, carboxylate and ammonium carboxylate are preferably used.

The raw material of tungsten or chromium is not particularly limited as long as it is a substance containing these, but it is preferable to use a compound containing these elements or a metal obtained by solubilizing a metal of these elements with an appropriate reagent. it can. Compounds containing these elements usually include nitrates, sulfates, carboxylate salts, ammonium carboxylate salts, ammonium halide salts, oxides, halides, hydroxides, hydrated oxides, hydrogen acid, acetylacetate. Nartate, alkoxide and the like can be used, but nitrate, carboxylate and ammonium carboxylate are preferably used.

The method of preparing the composite oxide is not particularly limited, and a method of mixing each raw material of the composite oxide as a solution or slurry of water or an organic solvent and then preparing the mixed metal oxide and a method of mixing the raw materials of the composite metal oxide And then heating and preparing by a solid-phase reaction. However, a method of preparing a solution or a slurry-like aqueous liquid containing each component, followed by drying and baking is more preferable.

For example, as a method for producing a composite metal oxide containing niobium, bismuth and vanadium, an aqueous solution of ammonium metavanadate and an aqueous solution of ammonium niobium oxalate are dissolved in a solution of bismuth nitrate in a 10% aqueous nitric acid solution. Each metal element is sequentially added at a quantitative ratio such that the atomic ratio becomes a predetermined ratio, and the obtained mixed solution is
A method of drying by a drying method such as an evaporation to dryness method, a spray drying method, a freeze drying method, a vacuum drying method, and the like, and further firing the obtained dried product may be mentioned.

The firing method can be arbitrarily adopted depending on the properties and scale of the dried product. For example, heat treatment on an evaporating dish, heat treatment using a heating furnace such as a rotary furnace, a fixed-bed firing furnace, a fluidized-bed firing furnace, and the like can be given. These firing methods may be performed by a single method or a combination of a plurality of methods.

The firing conditions vary depending on the firing method, but the temperature is usually 200 to 900 ° C., preferably 250 to 750 ° C., and the time is generally 0.5 to 30 hours, preferably 1 to 10 hours. The calcination is usually performed in an atmosphere of an oxygen-containing gas such as air, but may be performed in an atmosphere of an inert gas such as nitrogen, argon, or helium or in a vacuum.

In the catalyst of the present invention, the composite oxide thus produced may be used alone or may be supported on a well-known carrier component. The carrier component is not particularly limited, and examples thereof include silica, alumina, titania, zirconia, aluminosilicate, and diatomaceous earth.
Preferred is silica, alumina, or a mixture of silica and alumina. Particularly preferred is alumina or a mixture of silica and alumina. One or more carriers may be used in combination.

The weight ratio of the carrier component is not limited, but is usually 1 to 90% by weight, preferably 10 to 70% by weight, when expressed as a percentage of the weight of the carrier component with respect to the weight of the whole catalyst. Further, the catalyst of the present invention may contain a metal oxide other than the complex oxide represented by the general formula (1) as a binder or a diluent.

The catalyst according to the invention is used for the (ammo) oxidation of alkanes. In the present invention, (ammoxidation) refers to both ammoxidation and oxidation carried out in the absence of ammonia. The alkane used in the present invention includes, for example, alkanes such as methane, ethane, propane, n-butane, isobutane, pentane, hexane, heptane, and cyclohexane, and preferably a lower alkane having 1 to 4 carbon atoms, particularly preferably. Include propane and isobutane.

The catalyst of the present invention is used in a reaction for producing a nitrile by ammoxidizing an alkane. Ammoxidation is a method of performing a gas phase oxidation reaction in the presence of ammonia. The ammoxidation reaction of the alkane is carried out by supplying an oxygen-containing gas together with the catalyst of the present invention, the alkane, and ammonia into the reactor.

The alkane used for producing the nitrile of the present invention includes, for example, methane, ethane, propane, n
Alkanes such as butane, isobutane, pentane, hexane, heptane, cyclohexane, etc., in consideration of the industrial use of the obtained nitrile, preferably a lower alkane having 1 to 4 carbon atoms, and acrylonitrile, methacryloyl as a nitrile to be formed. In particular, propane and / or isobutane are preferably used because nitriles can be obtained in a high yield.

As the oxygen-containing gas, molecular oxygen is generally used. As the molecular oxygen, oxygen gas, air and the like are usually used, and these are inert gases such as nitrogen, helium, and the like. It may be diluted with argon or the like. The ratio of oxygen supplied to the reactor is not particularly limited, but in consideration of the yield and selectivity of acrylonitrile to be produced, it is usually 0.1 to 10 mol times, preferably 0.3 to 5 mol times, relative to the alkane. Particularly preferably, it is 0.5 to 4 times the molar amount.

The proportion of ammonia supplied to the reactor is not particularly limited, but is usually 0.05 to 5 mol times, preferably 0.1 to 4 mol times, relative to the alkane. The reaction conditions for the ammoxidation vary depending on the composition of the reaction gas, the composition of the catalyst used, and the type of nitrile to be produced, and are not uniquely determined, but the reaction temperature is usually 350 to 600.
° C, preferably 400 to 550 ° C, and the gas space velocity SV in the gas phase reaction is usually 50 to 10,000 h ^-1 , preferably 200 to 10,000 h ^-1 .
Implemented in the range of 6000h ^-1 . The reaction pressure is usually carried out under atmospheric pressure, but may be under a low pressure or a low pressure.

As the reaction system, any of a fixed bed, a fluidized bed and the like can be adopted. However, since the reaction is an exothermic reaction, the control of the reaction temperature is easier in the fluidized bed system. In addition, the reaction can be carried out in a one-pass system in which the supplied alkane and ammonia are each converted at a high ratio of 80% or more, or the conversion of the supplied alkane is controlled to 50% or less, and the ammonia supply amount , The unreacted alkane can be separated from the product, and then supplied to the reactor again.

The catalyst of the present invention can also be used in a reaction for producing an aldehyde and / or a carboxylic acid by subjecting an alkane to gas phase oxidation. The production of aldehydes and / or carboxylic acids by gas phase oxidation of alkanes is carried out by feeding the catalyst of the present invention, alkanes and an oxygen-containing gas into a reactor.

The alkane used in the production of the aldehyde and / or carboxylic acid of the present invention includes, for example, alkanes such as methane, ethane, propane, n-butane, isobutane, pentane, hexane, heptane and cyclohexane. In view of the industrial use of the obtained aldehyde and / or carboxylic acid, a lower alkane having 1 to 4 carbon atoms, particularly propane, is preferably used.

As the oxygen-containing gas, molecular oxygen is usually used. As the molecular oxygen, oxygen gas, air, etc. are usually used. These are gases inert to the reaction, for example, nitrogen, helium, and the like. It may be diluted with argon or the like. The proportion of oxygen supplied to the reactor is not particularly limited, but is usually 0.1 to alkane in consideration of the yield and selectivity of the aldehyde and / or carboxylic acid formed.
The amount is from 10 to 10 times, preferably from 0.3 to 5 times, particularly preferably from 0.5 to 4 times.

The reaction conditions for producing an aldehyde and / or a carboxylic acid by gas phase oxidation of an alkane differ depending on the composition of the reaction gas, the composition of the catalyst used, and the type of the aldehyde and / or the carboxylic acid to be produced. Although not determined, the reaction temperature is usually 350 to
600 ° C., preferably 400 to 550 ° C., the gas space velocity SV in the gas phase reaction is usually 50 to 10,000 h ⁻¹ , preferably 2
It is performed in the range of 00 to 6000 h ^-1 . The reaction pressure is usually carried out under atmospheric pressure, but may be under a low pressure or a low pressure.

As the reaction system, any of a fixed bed, a fluidized bed and the like can be adopted. However, since the reaction is an exothermic reaction, the control of the reaction temperature is easier in the fluidized bed system. In addition, it can be carried out in a one-pass system in which the supplied alkane is converted at a high rate of 80% or more, and the conversion of the supplied alkane is controlled to 50% or less to separate unreacted alkane from the product. Alternatively, it can be carried out again by a recycling system in which the mixture is supplied to the reactor.

[0035]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples unless it exceeds the gist. In the following Examples and Comparative Examples, the conversion (%) of propane (hereinafter sometimes referred to as “PPA”) and acrylonitrile (hereinafter “A
N ") (yield (%)) and acrylonitrile selectivity (%) are calculated by the following formulas.

PPA conversion (%) = (moles of propane consumed / moles of supplied propane) × 100 AN yield (%) = (moles of acrylonitrile formed / moles of supplied propane) × 100 AN selectivity (%) = (moles of acrylonitrile formed / moles of propane consumed) × 100

Example 1 The general formula is Nb_TenBi_3.5V_0.53O_nThe composite oxide is
Prepared as follows. 9.70g bismuth nitrate in 10% nitric acid aqueous solution
・ Dissolve pentahydrate and add 0.35 g of metavanadate
Aqueous solution of ammonium, 25.70 g of niobium oxalate
An aqueous solution in which ammonium was dissolved was sequentially added. This solution
After evaporating the solution to dryness on a magnetic dish, heat it as it is to remove it.
Decomposed to remove NOx. Then bake at 700 ℃ for 3 hours
Was. This complex oxide was charged into a reactor, and the reaction temperature was 520
℃, space velocity SV about 400hr ^-1And propane: Ammo
Gas is supplied at a molar ratio of near: air = 1: 1.2: 15,
An ammoxidation reaction was performed. The reaction results are shown in Table 1.

[0038] EXAMPLE 2 Formula composite oxide is _{Nb 10 Bi 3.7 V 1.1 O n} , ammonium metavanadate 0.70 g, except that the 24.35g of ammonium niobium oxalate in the same manner as in Example 1 Preparation did. This composite oxide was charged into a reactor, and
A gas-phase ammoxidation reaction was carried out under the same conditions as described above. The reaction results are shown in Table 1.

[0039] EXAMPLE 3 Formula composite oxide is _{Nb 10 Bi 3.9 V 1.8 O n} , ammonium metavanadate 1.35 g, except that the 23.01g of ammonium niobium oxalate in the same manner as in Example 1 Preparation did. This composite oxide was charged into a reactor, and
A gas-phase ammoxidation reaction was carried out under the same conditions as described above. The reaction results are shown in Table 1.

[0040] Example 4 formula to prepare a composite oxide is _{Nb 10 Bi 4.1 V 0.6 Cr 0.6} O n as follows. Dissolve 9.70 g of bismuth nitrate pentahydrate in 10% nitric acid aqueous solution, and add chromium nitrate
1.10 g aqueous solution, ammonium metavanadate
0.32 g dissolved aqueous solution, niobium ammonium oxalate
An aqueous solution in which 22.33 g was dissolved was sequentially added. The solution was evaporated to dryness on a magnetic dish, heated as it was, denitrified, and NOx was removed. Then, it was baked at 700 ° C. for 3 hours.
This composite oxide was charged into a reactor, and a gas phase ammoxidation reaction was performed under the same conditions as in Example 1. The reaction results are shown in Table 1.

[0041] EXAMPLE 5 Formula composite oxide is _{Nb 10 Bi 3.5 V 0.6 W 0.6} O n,
8.73 g of bismuth nitrate pentahydrate, 50% by weight in terms of WO ₃ instead of an aqueous solution of chromium nitrate nonahydrate
Aqueous ammonium metatungstate solution equivalent to 1.2
It was prepared in the same manner as in Example 4 except that 5 g was added. This composite oxide was charged into a reactor, and a gas phase ammoxidation reaction was performed under the same conditions as in Example 1. The reaction results are shown in Table 1.

[0042] EXAMPLE 6 Formula composite oxide is _{Nb 10 Bi 3.5 V 0.6 W 1.1} O n,
Same as Example 4 except that bismuth nitrate pentahydrate was 8.31 g, ammonium metatungstate aqueous solution corresponding to 50% by weight in terms of WO ₃ was 2.50 g, and niobium ammonium oxalate was 21.09 g. Prepared. This composite oxide was charged into a reactor, and a gas phase ammoxidation reaction was performed under the same conditions as in Example 1. The reaction results are shown in Table 1.

[0043] EXAMPLE 7 Formula is _{Nb 10 Bi 3.5 V 0.6 W 1.1} O n composite oxide 50
After adding a catalyst consisting of 25% by weight of SiO ₂ as a carrier and 25% by weight of Al ₂ O ₃ as a carrier, an aqueous solution in which niobium ammonium oxalate was dissolved was added, 27.50 g of alumina sol and 13.75 g of silica sol were added. It was prepared in the same manner as in Example 6 except that the sintering temperature was changed to 610 ° C. The catalyst containing the composite oxide was filled in a reaction tube, and a gas phase ammoxidation reaction was performed under the same conditions as in Example 1. The reaction results are shown in Table 1.

[0044] The composite oxide that is Embodiment 8 general formula _{Nb 10 Bi 3.9 V 0.56 Ti 0.56} O n, bismuth nitrate pentahydrate and 9.30 g, 0.86 g instead of chromium nitrate nonahydrate The preparation was performed in the same manner as in Example 4 except that an aqueous solution in which titanium ammonium oxalate was dissolved was added. This composite oxide was charged into a reactor, and a gas phase ammoxidation reaction was performed under the same conditions as in Example 1. The reaction results are shown in Table 1.

Comparative Example 1 A composite oxide having a general formula of Nb ₁₀ O ₂₅ was prepared by evaporating an aqueous solution in which 20 g of niobium ammonium oxalate was dissolved and evaporating it to dryness, followed by baking at 700 ° C. for 3 hours. This composite oxide was charged into a reactor, and a gas phase ammoxidation reaction was performed under the same conditions as in Example 1. The reaction results are shown in Table 1. From these results, it can be seen that an effective reaction result cannot be obtained with a single oxide of niobium.

Comparative Example 2 A composite oxide having the general formula Nb ₁₀ Bi ₁₀ O ₄₀ was prepared as follows. 14.55 g of bismuth nitrate pentahydrate was dissolved in a 10% aqueous nitric acid solution, and an aqueous solution in which 13.60 g of niobium ammonium oxalate was dissolved was added. After evaporating this solution to dryness, it was decomposed in air to remove NOx. Then, it was fired at 700 ° C. for 3 hours. This composite oxide was charged into a reactor, and a gas phase ammoxidation reaction was performed under the same conditions as in Example 1. The reaction results are shown in Table 1. From this result, it can be seen that a composite oxide of niobium and bismuth cannot provide an effective reaction result.

[0047] Similarly to Comparative Example 3 Formula composite oxide is Nb ₁₀ Bi _3.4 O _n, bismuth nitrate pentahydrate and 9.70 g, except that the 27.20g of ammonium niobium oxalate and Comparative Example 2 Was prepared. This composite oxide was charged into a reactor, and a gas phase ammoxidation reaction was performed under the same conditions as in Example 1. Table 1 shows reaction results
Shown in From this result, it can be seen that a composite oxide of niobium and bismuth cannot provide an effective reaction result.

The aqueous solution of Comparative Example 4 Formula composite oxide is _{Nb 10 Bi 3.5 Mo 0.6 O n} , ammonium niobium oxalate and 27.34G, dissolved ammonium paramolybdate 0.56g instead of ammonium metavanadate Was prepared in the same manner as in Example 1 except that was added. This composite oxide was charged into a reactor, and a gas phase ammoxidation reaction was performed under the same conditions as in Example 1. The reaction results are shown in Table 1. From these results, it can be seen that a composite oxide of niobium, bismuth and molybdenum cannot provide an effective reaction result.

[0049] Comparative Example 5 Formula composite oxide is _{Nb 10 Bi 20 V 17 W 10} C r10 O n,
9.70g bismuth nitrate pentahydrate, 4.00 g of chromium nitrate nonahydrate, 1.64 g of ammonium metavanadate, ammonium niobium oxalate and 4.53 g, the WO ₃ after the aqueous solution of ammonium metavanadate Convert
It was prepared in the same manner as in Example 4 except that 4.64 g of an aqueous solution of ammonium metatungstate corresponding to 50% by weight was added. This composite oxide was filled in a reactor, and a gas phase ammoxidation reaction was performed under the same conditions as in Example 1. The reaction results are shown in Table 1. From these results, it is understood that an effective reaction result cannot be obtained with a composite oxide containing both elements of tungsten and chromium at the same time.

[0050] Comparative Example 6 Formula composite oxide is _{Nb 10 Bi 4.9 V 0.7 W 1.3} Cr 1.3 O n, 2.20g of chromium nitrate nonahydrate, 4.53 g of ammonium niobium oxalate, ammonium metavanadate To
It was prepared in the same manner as in Comparative Example 5 except that an aqueous solution of ammonium metatungstate corresponding to 0.32 g, 50% by weight in terms of WO ₃ was changed to 2.54 g, and ammonium niobium oxalate was changed to 18.63 g. This composite oxide was charged into a reactor, and a gas phase ammoxidation reaction was performed under the same conditions as in Example 1. The reaction results are shown in Table 1. From these results, it is understood that an effective reaction result cannot be obtained with a composite oxide containing both elements of tungsten and chromium at the same time.

[0051]

[Table 1]

[0052]

According to the present invention, acrylonitrile, acrylic acid and the like useful as industrial raw materials can be produced by using the novel composite oxide.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C07C 253/24 C07C 253/24 255/08 255/08 F term (Reference) 4G069 AA15 BB06A BC16A BC25A BC25B BC50A BC50B BC54A BC54B BC55A BC55B BC58A BC58B BC60A BC60B BC66A CB53 DA05 4H006 AA02 AC45 AC46 AC54 BA09 BA10 BA12 BA13 BA14 BA19 BE14 BE30 BS10 4H039 CA62 CA65 CA70 CC30 CL50

Claims (7)

[Claims] 1. A catalyst for (ammo) oxidizing alkane, comprising a complex oxide represented by the following general formula (1). _{Nb a Bi b V c X d} Z e O n (1) ( wherein, X represents one or more elements selected from the group consisting of titanium, iron and aluminum, Z is showed chromium or tungsten, a When b = 10, b = 0.1-9, c = 0.1-10, d = 0-5, e = 0-5, and n represents a number determined by the oxidation state of other elements. ) 2. The catalyst according to claim 1, wherein the alkane is ammoxidized to produce a nitrile. 3. An ammoxidation of an alkane in the presence of a catalyst,
A method for producing a nitrile, wherein the catalyst is used as a catalyst.
5. A method for producing a nitrile using the catalyst described in 1. above. 4. The method for producing a nitrile according to claim 3, wherein the alkane is propane and / or isobutane. 5. The catalyst according to claim 1, wherein the alkane is oxidized to produce an aldehyde and / or a carboxylic acid. 6. A method for producing an aldehyde and / or carboxylic acid by oxidizing an alkane in the presence of a catalyst, wherein the catalyst according to claim 5 is used as a catalyst. 7. The method for producing an aldehyde and / or carboxylic acid according to claim 6, wherein the alkane is propane.