JP2001198467A - Method for producing tellurium-containing oxide catalyst and method for gas-phase catalytic oxidation reaction of alkane using the same - Google Patents

Abstract

(57) [Problem] To provide a method for producing a catalyst capable of improving the selectivity and the yield of a gas phase catalytic oxidation reaction product. A method for producing an oxide catalyst for use in a catalytic oxidation reaction of an alkane, wherein the content of copper or silver is 5 to 200 ppm by weight in a method for producing an oxide catalyst containing at least tellurium. A solution or slurry containing tellurium is prepared, and then dried and calcined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a tellurium-containing oxide catalyst and a gas-phase catalytic oxidation reaction method using the same. More specifically, the present invention relates to a method for producing a highly active tellurium-containing oxide catalyst used in a gas phase catalytic oxidation reaction of alkanes.

[0002]

2. Description of the Related Art A complex oxide containing tellurium as an essential component has been widely known as a catalyst, especially as a partial oxidation catalyst. JP-A-9-157241
Discloses the ammoxidation reaction of propane to acrylonitrile at temperatures below 450 ° C. using a catalyst containing tellurium. Tellurium is inexpensive and has no soluble compounds that are easily available on an industrial scale.Often, even if the catalyst has excellent performance, sufficient economics cannot be secured for industrial-scale implementation, or its original activity is low. It may not be fully demonstrated.

Japanese Patent Application Laid-Open No. 56-126448 relates to a method for producing an antimony-containing oxide catalyst for oxidizing olefins, which comprises a tellurium-containing impregnating liquid for impregnating an antimony-containing oxide composition with tellurium. A method is disclosed in which tellurium metal is dissolved with hydrogen peroxide using an aqueous solution containing ammonium ions, alkali metal ions, or one of vanadium, molybdenum, and oxygen acid (oxometalate) of tungsten. Here, it is further described that additional elements other than vanadium, molybdenum, and tungsten such as copper and silver may be contained in the tellurium-containing impregnation liquid in an amount of 0 to 5 times (atomic ratio) relative to tellurium. However, there is no mention of the effect due to the presence of these additional elements, and all specifically disclosed data are those in which the abundance of these elements is zero.

JP-A-59-227703 relates to a method of dissolving tellurium metal with hydrogen peroxide, and by reducing the amount of copper or silver contained in the tellurium metal to 0.02 wt% or less, the peroxide of tellurium is reduced. It is disclosed that the dissolution rate in hydrogen is improved. The publication does not disclose any specific example of the gas phase catalytic oxidation reaction, and describes that it is preferable that the content of copper or silver is as small as possible from the viewpoint of tellurium solubility. There is no description of the effect of the oxide catalyst on the reaction performance of the obtained oxide catalyst when it is present. JP-A-11-226408 discloses that when preparing an oxide catalyst containing tellurium, Mo,
A method for producing a metal oxide catalyst in which an oxometalate such as W or V is reacted with metal tellurium is disclosed.

[0005] On the other hand, many catalysts have been proposed for the production of unsaturated nitriles by the vapor-phase ammoxidation of alkanes, but the yield and selectivity are not yet sufficient, and the yield of nitriles is not sufficient. It has been desired to develop a catalyst which can improve the performance and is easy to produce. As a method for improving the yield of the target nitrile in the ammoxidation of alkanes, for example, JP-A-4-275266 and JP-A-6-135921 disclose a method of adding copper. JP-A-3-58961 discloses a catalyst containing silver as an essential component.

[0006]

However, the effect of adding copper, silver and other elements in these conventional methods greatly varies depending on the type of catalyst used, and the optimum content and addition method for each catalyst are different. Is usually different. Further, a step of separately adding a large amount of these elements is required, and there is a problem that the step of preparing the catalyst increases. Furthermore, when these elements are separately added, it is customary to use a water-soluble salt such as a nitrate,
There is a problem that nitrate groups cause corrosion of the catalyst manufacturing equipment, or that the uniformity of the raw material solution is hindered by the generation of insolubles due to compatibility with other catalyst raw materials. In particular, in the case of a catalyst used for gas phase catalytic oxidation of alkanes, it is presumed that this will have a significant effect on the performance of the obtained catalyst, and it has not been easy to find an industrially advantageous method for producing a catalyst. It is an object of the present invention to remedy the disadvantages of the prior art and to provide a more industrially advantageous process for producing oxide catalysts, especially for use in the gas-phase catalytic oxidation of alkanes.

[0007]

The present inventors have made intensive studies to overcome the above-mentioned problems. As a result, when metallic tellurium is used as a tellurium raw material, metallic tellurium products of various purity are industrially used. Among them, in particular, by selecting and using metal tellurium containing a specific amount of copper or silver, the problem of corrosion of the device does not occur, the unsaturated nitrile and the nitrile can be easily formed by a simple process. The present inventors have found that a catalyst having an improved yield of a target substance such as an unsaturated carboxylic acid can be produced, and have reached the present invention.

That is, the gist of the present invention is to provide an oxide catalyst for use in a gas phase catalytic oxidation reaction of alkanes, wherein the content of copper or silver is at least one in a method for producing an oxide catalyst containing at least tellurium. A method for producing a tellurium-containing oxide catalyst, comprising preparing a solution or slurry containing 5 to 200 ppm by weight of metal tellurium, followed by drying and calcining.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

A feature of the present invention is an oxide catalyst for use in a gas phase catalytic oxidation reaction of alkanes, wherein copper or silver is used as a tellurium raw material for use in producing an oxide catalyst containing at least tellurium. 5-200pp by weight fraction
m, preferably 10 to 200 ppm, more preferably 2
The use of metallic tellurium containing 0 to 200 ppm. The total content of copper and silver is 10 to 300 pp.
m, preferably from 50 to 250 ppm. Furthermore, calcium is 8 to 2000 pp by weight fraction.
m, preferably 12 to 1800 ppm, or 18 to 200 ppm, preferably 20 to 1 ppm by weight of tin.
00ppm or 5-20pb lead by weight
It is preferred to use pm-containing metal tellurium.

In the present invention, the use of tellurium metal containing the above-mentioned elements in the above-mentioned content range can improve the yield, selectivity, and alkane conversion of the desired product. When the content is less than the lower limit of the above range, a great effect of improving the yield is not recognized, and when the content exceeds the upper limit of the above range, for example, copper and silver are disclosed in JP-A-59-227703. As described above, decomposition of the oxidizing agent makes it difficult to dissolve metal tellurium.

[0011] The cause of the improvement in the yield due to the presence of a specific element in the tellurium metal in a specific amount is not sufficiently clear. However, when tellurium is dissolved and combined with other catalyst constituents, these elements are not considered. It is presumed that the presence of these elements facilitates the incorporation of these elements into tellurium-containing oxides in a form effective for catalytic oxidation of alkanes. As a technique for analyzing trace impurities contained in tellurium metal, XR
An F (X-ray fluorescence analysis) method or an ICP-AES (Inductively Coupled Plasma Emission Spectroscopy) method is used.

When the content of copper or silver in the tellurium metal is large, it is preferable to remove these components in advance and adjust the content to the specific content according to the present invention before use.
As a method of adjusting, a method of dissolving metal tellurium powder in hydrochloric acid or sulfuric acid, reducing with sulfurous acid gas, filtering, washing and drying, or a method of distilling metal tellurium powder, an electrolytic method, and the like can be mentioned. .

The tellurium metal is usually dissolved by heating in a solvent in which an oxometalate such as ammonium paramolybdate, ammonium metavanadate or ammonium paratungstate is dissolved. As the form of tellurium metal, various forms such as a granular form and a powder form can be adopted, but from the viewpoint of ease of handling, safety and ease of dissolution, those having an average particle size of several tens of micrometers and several millimeters are preferable. Used. In particular, those having an average particle size of 50 to 300 micrometers are preferable. Examples of the solvent include water, alcohols such as ethylene glycol, ethanol, and methanol, and oxygen-containing organic solvents such as acetone and ether. Among them, water is preferably used.

Even when there is no oxidizing agent other than oxometalate, the oxometalate itself becomes the oxidizing agent and the tellurium metal is oxidized and dissolved, but by adding the oxidizing agent to the reaction system, It is preferable to promote the dissolution of tellurium metal. Examples of the oxidizing agent include normal or pressurized air, normal or pressurized oxygen, ozone, inorganic peroxides such as hydrogen peroxide, and organic peroxides. Oxygen, hydrogen peroxide and ozone are preferred, and hydrogen peroxide is particularly preferred. Since the reaction in which tellurium metal is oxidized to a tellurium compound having a higher oxidation number is exothermic, control of the reaction progress is extremely important in producing a catalyst on an industrial scale. Performing large-scale catalyst production without this control would lead to various risks and economics such as a rapid rise in temperature of the catalyst preparation solution, rapid foaming due to decomposition of the oxidant, and a decrease in efficiency due to self-decomposition of the oxidant. Causes a loss. The degree of progress of the oxidation reaction can be controlled by various methods such as controlling the heat removal rate of the reaction tank, the supply rate of the oxidizing agent, or the supply rate of tellurium metal. It is preferable to limit the oxidation reaction rate of tellurium metal within a certain range.

The supply rate of the oxidizing agent may be changed continuously while monitoring the temperature change of the catalyst preparation liquid, or the required amount may be divided into several parts and charged at intervals. When the oxidizing agent is divided and charged, the amount of one charging is determined by the amount of catalyst preparation generated due to the expected heat generation when tellurium metal is oxidized by the oxidizing agent charged at a time because of the ease of control. It is preferable that the temperature change is adjusted to fall within a predetermined range. At this time, the injection interval can be adjusted by monitoring the temperature of the catalyst preparation liquid, or by quantifying a compound generated by the combination of an oxidizing agent with an oxometalate such as molybdenum or vanadium by spectroscopy, or It is also possible to determine the concentration of the oxidizing agent in the solution by titration or the like, and to limit the oxidizing agent concentration in the catalyst preparation solution to a certain range.

The temperature of the catalyst preparation solution can be selected within an appropriate range depending on the structure of the vessel used for dissolution, the concentration of the reaction solution, and the like. More preferably, the temperature is controlled at 80 ° C. The state of tellurium after dissolution can take various forms depending on conditions, but after oxidation and dissolution, it is combined with oxometallate to form a certain kind of compound in which tellurium is a hetero atom, molybdenum, vanadium, etc. is a poly atom. It is presumed that it exists as a heteropolyoxometalate. In the solution containing tellurium thus obtained and oxometalate such as molybdenum and vanadium, a compound containing another catalyst component is dissolved or suspended as necessary so that a desired catalyst composition is obtained. The resulting solution or slurry is dried and calcined to obtain a metal oxide catalyst.

Compounds containing other catalyst components include oxo acid salts, carboxylate salts, ammonium halide salts, oxides, halides, acetylacetonates,
Alkoxides and the like can be used, but it is preferable to use a substance that gives a stable and homogeneous aqueous solution, or an oxide sol. Drying is performed by an evaporation to dryness method, a spray drying method, or a vacuum drying method, and a spray drying method is particularly preferred. The drying temperature varies depending on the composition of the tellurium-containing catalyst, but is usually 8
The temperature is 0 to 400 ° C, preferably 120 to 280 ° C, and more preferably 160 to 220 ° C.

The calcination is usually performed in an atmosphere of an inert gas such as a nitrogen gas having a limited oxygen concentration at a temperature of 350 to 700 ° C. for a time of 0.5 to 30 hours.
550-620 ° C in an inert gas stream of 0 ppm or less
It is particularly preferred that the temperature is maintained within the above temperature range for several hours. The firing method can take various forms such as a fixed bed method, a fluidized bed method, a kiln and a tunnel furnace, but a fluidized bed, a kiln and the like are industrially advantageous. If necessary, heat treatment can be performed prior to firing. Various forms of the heat treatment can be adopted, but it is advantageous industrially to carry out the heat treatment continuously using a kiln or the like. It is preferable that the heat treatment is performed under a flow of air, nitrogen gas or the like at 250 to 400 ° C. for a residence time of several seconds to several tens of minutes.

The metal oxide catalyst obtained by the production method of the present invention is used for producing an organic compound by a catalytic oxidation reaction of an alkane. What is the gas phase catalytic oxidation of alkanes?
The alkane is subjected to gas-phase catalytic oxidation with oxygen, but also includes reactions in which ammonia and water vapor are present in the reaction system in addition to oxygen, and includes various organic compounds such as oxygen-containing organic compounds, dehydrogenated organic compounds, and nitriles. Used for the production of compounds. Among the metal oxide catalysts obtained by the production method of the present invention, in particular, a catalyst containing both molybdenum, vanadium and tellurium (a catalyst containing Mo-V-Te) is a partial oxidation of alkanes having low reactivity among hydrocarbons. It also has excellent catalytic activity in the reaction, and the production of nitriles such as acrylonitrile (JP-A-2-257, 5-148212, 5-2081) can be performed by appropriately selecting the conditions of the gas phase catalytic oxidation reaction.
36, 9-157241) and various reactions such as production of α, β-unsaturated carboxylic acids such as acrylic acid (JP-A-6-287184).

As the oxide catalyst of the present invention, the catalyst composition represented by the empirical formula (1) is preferably used among various catalyst compositions.

Embedded image MoaVbTecXdOn (1)

In the formula (1), X is Ti, Zr, Nb, T
a, Cr, W, Mn, Fe, Ru, Co, Rh, Ir,
Ni, Pd, Pt, Cu, Ag, Zn, In, Sn, P
b, Bi, Ce, at least one metal element selected from alkali metals and alkaline earth metals;
When it is 1, 0.01 ≦ b ≦ 1, preferably 0.1 ≦ b
b ≦ 0.6, 0 <c ≦ 1, preferably 0.01 ≦ c ≦
0.4, 0 ≦ d ≦ 1, preferably 0.01 ≦ d ≦ 0.6
Where n is a value determined by the oxidation state of another element.

Although the metal oxide obtained by the method of the present invention can be used alone as a catalyst, the metal oxide obtained by the method of the present invention and one or more of Si, Al, Zr, Ti, and alkaline earth metals can be used. And a carrier component such as an oxide of the same may be used in the same particle. Further, the reaction may be performed in a state where particles containing a metal oxide and particles containing one or more oxides of Si, Al, Zr, Ti, and alkaline earth metals are mixed.

As the alkane as a raw material for the catalytic oxidation reaction,
Alkanes having 3 to 8 carbon atoms are preferred, and propane is particularly preferred. As an example of the reaction,
Production of unsaturated nitriles by ammoxidation of alkanes (eg, production of acrylonitrile by ammoxidation of propane, production of methacrylonitrile by ammoxidation of isobutane), production of unsaturated carboxylic acids by partial oxidation of alkanes (eg, Production of acrylic acid from propane, production of methacrylic acid from isobutane, etc.), simultaneous production of nitrile and unsaturated carboxylic acid by partial oxidation of alkane in the presence of ammonia (eg simultaneous production of acrylonitrile and acrylic acid from propane) ), Oxidative dehydrogenation of alkanes (eg, production of ethylene from ethane, propene from propane, etc.), production of acid anhydrides by partial oxidation of various alkanes (eg, production of maleic anhydride from butane, etc.).

The conditions for the catalytic oxidation reaction of alkanes using the metal oxide catalyst obtained by the production method of the present invention are as follows. In the case of the partial oxidation reaction of alkanes, the catalyst can be used even at a relatively low temperature of 500 ° C. or lower. Has a high partial oxidation activity, so that the reaction temperature is 300-500.
° C., preferably gas space velocity in the three hundred fifty to four hundred eighty ° C., the gas phase reaction (SV) is 100~10000hr ^-1, preferably in the range of 300~6000hr ^-1, the pressure of the reaction is not particularly limited. In addition, nitrogen,
An inert gas such as helium or argon can also be used. The reaction can be carried out in either a fixed bed or a fluidized bed.
The fluidized bed is easier to control the temperature. In addition, the removal of heat of reaction in the fluidized bed can be further facilitated by the presence of oxide particles inert to the reaction in the reaction system.

The metal oxide catalyst obtained by the production method of the present invention is particularly effective in the production of acrylonitrile from propane among the ammoxidation reactions of alkanes. In this case, in the reaction feed gas, oxygen is 0.2 to 4 times the molar amount of propane, and ammonia is 0.1 to 1 mole of the propane.
A range of from 3 to 3 moles is preferred. Further, the metal oxide catalyst obtained by the production method of the present invention can obtain acrylic acid in a high yield by a partial oxidation reaction of an unsaturated carboxylic acid, particularly propane by partial oxidation of alkane. As the raw material gas, propane and an oxygen-containing gas are used.
Further, it is preferable to use steam, and it is possible to suppress the generation of carbon dioxide gas and the like and to further increase the selectivity of acrylic acid.
Further, the metal oxide catalyst obtained by the production method of the present invention,
Reaction conditions for the partial oxidation reaction of propane in the presence of ammonia, especially the molar ratio of ammonia to propane, oxygen,
Acrylonitrile and acrylic acid can be produced simultaneously by controlling the reaction temperature and the like.

[0026]

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. The propane conversion (%), acrylonitrile (AN) selectivity (%), and acrylonitrile (A) in the following Examples and Comparative Examples.
N) The yield (%) is represented by the following formula.

## EQU1 ## Propane conversion (%) = (moles of propane consumed / moles of supplied propane) × 100 AN selectivity (%) = (moles of produced AN / moles of propane consumed) × 100

(Method of Analyzing Tellurium Metal) A tellurium metal sample was prepared by ICP-AES (inductively coupled plasma emission spectroscopy).
Analysis was performed by a standard addition method using an apparatus JY38S. The analysis method is described below. A tellurium metal sample (about 2 g) was precisely weighed and transferred to a 200 ml beaker. In addition, Mitsubishi Chemical Corporation's "Hydrochloric acid for EL electronics industry (containing 36% hydrogen chloride)" 1
0 ml, and the company's nitric acid for EL electronics industry (nitric acid 70%
2) and dissolved on heating on a hot plate. Transfer most of this solution to a 50 ml volumetric flask,
Further, the solution remaining in the beaker was added to 10 ml of "Hydrochloric acid for EL Electronics (containing 36% of hydrogen chloride)" manufactured by Mitsubishi Chemical Corporation, and the solution was put into the volumetric flask while being washed. This operation of washing the beaker with hydrochloric acid was repeated twice. Next, water was added to the volumetric flask, and the volume was adjusted to 50 ml. This is referred to as solution A. A mixed standard solution (concentration of 5 ppm for each element) of the element to be measured (Cu, Ag, Ca, Sn, Pb) was prepared. This is referred to as solution B.

10 ml of the solution A was collected by a whole pipette, transferred to a 50 ml measuring flask, and further mixed with 5 ml of water.
And "Hydrochloric acid for EL electronics industry (hydrogen chloride 3
5%). Next, the volume was adjusted with water.
This aqueous solution is referred to as solution 1. 10 ml of the solution A was collected by a whole pipette, transferred to a 50 ml measuring flask,
Further, 5 ml of Solution B and 5 ml of “EL electronic industrial hydrochloric acid (containing 36% of hydrogen chloride)” manufactured by Mitsubishi Chemical Corporation were added, and the volume was then made constant with water. This aqueous solution is referred to as solution 2. Solution A
Was transferred to a 50 ml volumetric flask, and 10 ml of the solution B and "Hydrochloric acid for EL Electronics (containing 36% hydrogen chloride)" manufactured by Mitsubishi Chemical Corporation were used.
5 ml was added and then made up to volume with water. This aqueous solution is referred to as solution 3. Prepare prepared solutions 1, 2, and 3 with ICP-AE
It was measured by S apparatus. In the measurement, the emission intensity of the background was measured by setting the emission intensity at the peak top of the emission peak, setting two background positions (one at the long wavelength side and one at the short wavelength side at the peak top). , Background correction was performed. Number of measurement repetitions:
Five times, measurement time: 3 sec / pts. The measurement wavelengths are Cu: 224.700 nm and Ag: 32, respectively.
8.068 nm, Ca: 393.366 nm, Sn:
189.989 nm and Pb: 220.353 nm. Tellurium metal used (commercially available, average particle size about 150
Table 1 shows the analysis results (micrometers) (content of each element: weight fraction ppm).

[0029]

[Table 1] Table 1 ──────────────────────────────────── Copper Silver Calcium Tin Lead ppm ppm ppm ppm ppm ──────────────────────────────────── Sample A 61 77 14 697 Sample B 10 Less than 3 6 15 3 ────────────────────────────────────

[0030] was prepared metal oxide catalyst of Example 1 catalyst prepared composition is represented by _{Mo 1 V 0.3 Nb 0.12 Te 0.23} O n as follows. 100m
Ammonium paramolybdate in beaker 5.8
9 g was dissolved in 30 ml of water, and tellurium metal sample A 0.9
79 g were suspended at room temperature. To this, 2.73 g of a 35% aqueous hydrogen peroxide solution was added, and the mixture was heated to 70 ° C. while stirring with a cover with a watch glass. The solution turned from colorless to yellow simultaneously with the dropwise addition of hydrogen peroxide. With continued heating and stirring, the solid tellurium metal was completely dissolved, and the solution became transparent. After dissolution, 1.17 g of ammonium metavanadate was added,
After forming a homogeneous solution, niobium ammonium oxalate (manufactured by Starck; X ₃ NbO (C ₂ O ₄ ) ₃ and X ₂ NbO (O
H) A mixture of (C ₂ O ₄ ) ₂ [where X = NH ₄ ⁺ or H ⁺ ], Nb: 20.5 wt%, C ₂ O ₄ : 54.0
(wt%, NH ₃ : 5.1 wt%)
1 was added thereto, and the following operation was repeated to obtain a dried solid from the resulting slurry. The resulting slurry was sprayed on a commercially available hot plate heated to about 200 ° C. with a commercially available sprayer, dried, and immediately removed from the hot plate. The time required for the slurry sprayed on the hot plate to dry in one spray was about 10 seconds or less. This dried solid was heated in a nitrogen stream within about 20 minutes from room temperature until the solid temperature reached 350 ° C., and then cooled. Then, the temperature is raised from room temperature to 600 ° C. in about 1 hour in a nitrogen stream, and 600 ° C.
After calcining at 200C for 2 hours, the mixture was allowed to cool to 200C or lower in a nitrogen stream to obtain a metal oxide catalyst. Metal oxide catalyst 75m
g in a Pyrex glass fixed bed reactor having an inner diameter of 4 mm, and the molar ratio of propane / ammonia / air was 1 /
The ammoxidation reaction of propane was carried out at a space velocity (SV) of about 6000 hr ^-1 under a reaction gas flow of 0.3 / 4. At a reaction temperature of 410 ° C., the propane conversion was 25% and the AN selectivity was 62. 5.5%, AN yield 15.6%
Met.

COMPARATIVE EXAMPLE 1 In the same manner as in Example 1 except that Sample B was used instead of Sample A as tellurium metal, the catalyst charge composition was Mo _1.
The metal oxide catalyst represented by V _0.3 Nb _0.12 Te _0.23 O _n was prepared. A propane ammoxidation test was performed according to the method described in Example 1. As a result, at a reaction temperature of 410 ° C., the propane conversion was 21.3% and the AN selectivity was 61.3.
% And the AN yield was 13.0%.

[0032]

According to the catalyst preparation method of the present invention, the selectivity and the yield of the target product can be improved in the catalytic gas-phase oxidation reaction of alkanes, and industrially inexpensive. This is extremely useful because a highly active catalyst can be easily produced by a simple process using tellurium metal.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (reference) C07C 255/08 C07C 255/08 // C07B 61/00 300 C07B 61/00 300 F term (reference) 4G069 AA08 AA09 BB01A BB01C BB02A BB02B BB06A BB06B BC09A BC09B BC21A BC21B BC22A BC22B BC31A BC31B BC32A BC32B BC54A BC54B BC55B BC59A BC59B BD02 BA BD02B BD10A BD10B BD10C CB14 CB17 CB14 CB17 CB14 CB17 CB20 BA30 BC32 BS10 QN24 4H039 CA66 CA70 CC10 CC30

Claims (11)

[Claims] 1. A method for producing an oxide catalyst for use in a gas-phase catalytic oxidation reaction of an alkane, which comprises at least tellurium, wherein the content of copper or silver is 5 to 5% by weight. A method for producing a tellurium-containing oxide catalyst, comprising preparing a solution or slurry containing 200 ppm of metal tellurium, followed by drying and calcining. 2. The total content of copper and silver is 10% by weight.
The method for producing a tellurium-containing oxide catalyst according to claim 1, wherein metal tellurium having a concentration of from 300 to 300 ppm is used. 3. A calcium content of 8 to 2,000 p by weight.
The method for producing a tellurium-containing oxide catalyst according to claim 1, wherein a tellurium-containing metal tellurium is used. 4. The method for producing a tellurium-containing oxide catalyst according to claim 1, wherein metal tellurium containing 18 to 200 ppm of tin by weight is used. 5. The method for producing a tellurium-containing oxide catalyst according to claim 1, wherein metal tellurium containing 5 to 20 ppm by weight of lead is used. 6. An oxide catalyst comprising tellurium, molybdenum and vanadium as catalytically active components.
The method for producing a tellurium-containing oxide catalyst according to any one of the above. 7. The method for producing a tellurium-containing oxide catalyst according to claim 1, wherein an oxidizing agent is present in the solution or slurry containing tellurium metal. 8. A method for carrying out a gas phase catalytic oxidation reaction of an alkane using the oxide catalyst prepared by the method according to claim 1. 9. The method according to claim 8, wherein the unsaturated nitrile is produced by reacting an alkane with ammonia and oxygen. 10. The method according to claim 8, wherein an unsaturated carboxylic acid is produced by reacting an alkane with oxygen. 11. The gas phase catalytic oxidation reaction method according to claim 8, wherein the alkane is an alkane having 3 to 8 carbon atoms.