JP2003170053A - Method for producing composite oxide catalyst - Google Patents

Abstract

(57) [Problem] To provide a composite oxide catalyst using Si as an auxiliary agent for supplying Mo and further improving catalyst performance such as a raw material conversion rate and a selectivity. SOLUTION: When producing a composite oxide catalyst containing at least Mo and Si by a process including integration and heating of a source compound of each component element in an aqueous system, a molybdenum (Mo) source compound is produced. At least in part,
An aqueous dispersion obtained by integrating a Mo-containing compound and a silicon (Si) -containing compound in an aqueous system is used.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a composite oxide catalyst containing Mo and Si as essential components, and preferably gas phase contact for producing acrolein or methacrolein from propylene, isobutene or tertiary butanol. Mo and Si used for selective reactions such as oxidation reaction, vapor-phase catalytic ammoxidation reaction for producing acrylonitrile or methacrylonitrile from propylene or isobutene, and vapor-phase catalytic oxidative dehydrogenation reaction for producing butadiene from butene The present invention relates to a composite oxide catalyst contained as an essential component and a method for producing the same.

[0002]

2. Description of the Prior Art Gas phase catalytic oxidation reaction for producing acrolein or methacrolein from propylene, isobutene or tertiary butanol, gas phase catalytic ammoxidation reaction for producing acrylonitrile or methacrylonitrile from propylene or isobutene, and butadiene from butene. It is well known that the Mo-Bi-based composite oxide catalyst is a useful catalyst in the selective reaction such as the gas-phase catalytic oxidative dehydrogenation reaction to be produced, and it is industrially widely used. .

Patent documents relating to the composition and manufacturing method of the Mo-Bi type composite oxide in these various reactions include Japanese Patent Publication Nos. 39-3670 and 48-1645.
48-4763, 48-17253,
55-41213, 56-14659, 56-23969, 56-52013, 57-26245, and JP-A-48-527.
No. 13, gazette 48-54027, gazette 48-57.
916, 55-20610 and 55-4.
No. 7144, No. 55-84541, No. 59-
Many publications such as the 76541 publication and the 60-122041 publication are known. Each of the catalysts described in these contains silicon as a carrier. As the silicon source compound, silica sol, silica gel, fumed silica and the like are generally used.

As a method for modifying the silicon raw material before addition, JP-A-11-179206 discloses a method in which a silica sol having a pH of 5 or less is used and a slurry after the silica sol is added is prepared in an acidic region. ing.

[0005]

However, in each of the above publications, silicon has been found to have an effect as a carrier, but no qualitative effect has been found.

Therefore, an object of the present invention is to provide a composite oxide catalyst in which Si is used as an auxiliary agent for supplying Mo and the catalytic performance such as raw material conversion rate and selectivity is further improved.

[0007]

The present invention provides a method of producing a composite oxide catalyst containing at least Mo and Si by a process including integration of a source compound of each component element in an aqueous system and heating. The problem has been solved by using an aqueous dispersion obtained by integrating a Mo-containing compound and a silicon (Si) -containing compound in an aqueous system as at least a part of the molybdenum (Mo) source compound. Of.

Since an aqueous dispersion obtained by integrating a Mo-containing compound and a Si-containing compound in an aqueous system is used as at least a part of the Mo source compound, a precursor of a complex oxide containing Mo is used. Since it is formed homogeneously, it is possible to further improve the catalyst performance such as the raw material conversion rate and selectivity of the obtained catalyst.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. Note that molybdenum (Mo), bismuth (Bi), silicon (Si), cobalt (Co), nickel (Ni), iron (Fe), magnesium (Mg), calcium (Ca), zinc (Zn), cerium (Ce). ), Samarium (Sm), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), thallium (Tl), boron (B), phosphorus (P), arsenic (A).
Each element of s) and tungsten (W) is described using the element symbol in parentheses. The composite oxide catalyst according to the present invention is a catalyst containing at least Mo and Si.

In addition to Mo and Si described above, if necessary, at least one of Fe, Co, or Ni can be used as an essential component of the constituent elements constituting the above composite oxide catalyst. Can be used.

As a preferred embodiment of the above complex oxide catalyst, a catalyst represented by the following general formula (1) is exemplified. Mo _a Bi _b Co _c Ni _d Fe _e Na _f X _g Y _h Z _i Si _j O _k (1) where X represents at least one of Mg, Ca, Zn, Ce or Sm, and Y represents K, At least one of Rb, Cs, and Tl is shown, and Z is at least one of B, P, As, and W. Further, a to k represent atomic ratios of the respective elements, and when a = 12, they are represented in the following range of values. b: 0.5 to 7 c: 0 to 10 d: 0 to 10 c + d: 1 to 10 e: 0.05 to 3 f: 0 to 1 g: 0 to 1 h: 0.04 to 0.4 i: 0 to 3 j: 0.5 to 48 k: a value satisfying the oxidation states of other elements

The above composite oxide catalyst can be used in various gas phase catalytic reactions, among which propylene,
Gas phase catalytic oxidation reaction for producing acrolein or methacrolein from isobutene or tertiary butanol, gas phase catalytic ammoxidation reaction for producing acrylonitrile or methacrylonitrile from propylene or isobutene, and gas phase catalytic oxidative reaction for producing butadiene from butene It is preferably used for any of the dehydrogenation reactions. When used in these reactions, higher catalyst conversion performance such as raw material conversion and selectivity can be obtained.

The above-mentioned source compound of each component element means one or two of the component elements constituting the above composite oxide catalyst.
A compound that contains one or more elements and can be made into an aqueous solution or a water suspension (for example, ammonium paramolybdate for Mo, ammonium phosphomolybdate for Mo and P, etc.).

As a source compound of Mo, which is one of the component elements of the above complex oxide catalyst, ammonium paramolybdate, molybdenum trioxide, molybdic acid, ammonium phosphomolybdate, phosphomolybdic acid, and a Mo-containing compound are used. Examples thereof include an aqueous dispersion (hereinafter, referred to as "Mo / Si integrated dispersion") obtained by integrating the Si-containing compound in an aqueous system. Among these Mo source compounds, when the above Mo / Si integrated dispersion is used as at least a part thereof, the catalytic performance of the obtained composite oxide catalyst is further improved. Mo / S used at this time
The amount of Mo in the i integrated dispersion is 1 in the Mo source compound.
0 to 100% by weight is preferable, and 40 to 100% by weight is preferable. If it is less than 10% by weight, the catalytic performance of the obtained composite oxide catalyst may not be sufficiently improved. In addition, the above Mo
Only the / Si integrated dispersion may constitute the Mo source compound.

The integration of the source compound of each component element in the aqueous system means that the aqueous solution or dispersion of the source compound of each component element is collectively or stepwise mixed or aged. . That is, (a) a method of collectively mixing the above-mentioned source compounds, (b) a method of collectively mixing the above-mentioned source compounds, and a aging treatment,
(C) A method of stepwise mixing the above-mentioned respective source compounds,
(D) The method of repeating stepwise mixing and aging treatment of each of the above source compounds, and the method of combining (a) to (d) are all integrated in the aqueous system of the above source element compounds. It is included in the concept of conversion. Here, the above-mentioned aging means
"Operation of processing industrial raw materials or semi-finished products under specific conditions such as constant time and constant temperature to obtain necessary physical properties and chemical properties, increase temperature, or progress predetermined reactions" Dictionary / Kyoritsu Publishing). In the present invention, the above-mentioned constant time refers to a range of 10 minutes to 24 hours, and the above-mentioned constant temperature refers to a range of room temperature to the boiling point of an aqueous solution or aqueous dispersion.

Further, the above integration does not mean that the above treatment is performed only on the source compound of each element, and alumina, silica-alumina, refractory oxide, etc., which may be used as necessary. The carrier material of (1) is also included as a target.

The above-mentioned heating means the formation of individual oxides and complex oxides of the source compounds of the above-mentioned respective component elements, formation of complex compound oxides and complex oxides formed by integration, and final formation. A heat treatment for forming a complex oxide. And heating is not necessarily limited to once. That is, this heating can be arbitrarily performed at each stage of the integration shown in the above (A) to (D), and may be additionally performed after the integration if necessary. The heating temperature is usually in the range of 200 ° C to 700 ° C.

Further, in the above integration and heating, other than these, for example, drying, crushing, molding and the like may be performed before, after or during the process.

The Mo-containing compound used for producing the Mo / Si integrated dispersion is not particularly limited as long as it is a compound containing Mo, and for example, as the above-mentioned Mo source compound. Examples thereof include ammonium paramolybdate, molybdenum trioxide, molybdic acid, ammonium phosphomolybdate, phosphomolybdic acid and the like. Further, as the Si-containing compound used for producing the Mo / Si integrated dispersion, silica,
Examples thereof include granular silica, colloidal silica and fumed silica. Among these, colloidal silka having high water dispersibility is preferable, and fumed silica having high selectivity is more preferable.

The fumed silica refers to ultrafine particulate anhydrous silica, which is produced by hydrolyzing silanes such as silicon tetrachloride in a flame of oxygen and hydrogen. Unlike silica produced by the wet process, primary particles of fumed silica exposed to high temperatures in the gas phase have only an outer surface. It is considered that this is extremely effective for good selectivity at high raw material conversion rates.

When the above fumed silica is used, its proportion is 40 to 100% by weight based on the whole Si-containing compound.
Is preferable, and 60 to 100% by weight is preferable. If it is less than 40% by weight, the effect of improving the selectivity due to the addition of fumed silica may not be sufficiently obtained.

The average particle size of primary particles of the fumed silica is preferably 15 to 50 nm, and more preferably 20 to 50 nm. If it is smaller than 15 nm, the viscosity of the aqueous dispersion becomes high, which may make the operation difficult. On the other hand, the thickness may be larger than 50 nm, but since it is technically difficult to manufacture, the thickness of 50 nm is sufficient. The average diameter of the above primary particles can be determined from an electron micrograph. Specifically, it is 1000-1 according to the electron micrograph.
The diameter of 0000 primary particles is measured, and the average value is 1
The secondary particle average diameter is used.

The above-mentioned fumed silica is preferably used in a state where the agglomerated particles are dispersed in an aqueous dispersion medium in advance, that is, as a fumed silica dispersion liquid. The above-mentioned primary particles of fumed silica are in a strong aggregation / aggregation state, and when they are suspended in water by a commonly used stirring blade type, they form aggregated particles even in the dispersion medium. According to the measurement by the inventors, when fumed silica having a primary particle average particle diameter of 7 to 50 nm is suspended in ion-exchanged water in a stirring impeller type, the average particle diameter of aggregated particles in water is 10 to 55 μm. Was in the range. The agglomerated particles are subjected to a dispersion treatment, and are used by making them finer to 5 μm or less. It is considered that the catalyst component mixed with the Si component is finely dispersed by this, and the raw material conversion rate is dramatically improved.

As the method for dispersing the agglomerated particles of fumed silica in the aqueous dispersion medium, any of the principles of medium flow, collision, pressure difference and ultrasonic wave may be used. For example, a dispersion method using a rotary shear flow such as a homogenizer, a homomixer, and a high shear blender can be used. Further, a dispersion method using an orifice contracting flow can be used. Furthermore, a dispersion method using ultrasonic waves can be used.

The average particle size of the agglomerated particles in the aqueous dispersion medium of the fumed silica subjected to the above dispersion treatment is 0.1
5 μm is preferable, 0.15 to 3 μm is preferable, and 0.15
˜1 μm is more preferred, and 0.15 to 0.5 μm is even more preferred. If it is more than 5 μm, a sufficient raw material conversion rate may not be obtained. On the other hand, even if it is smaller than 0.1 μm, it is considered to be advantageous in terms of catalyst performance, but it is technically difficult and there has been no achievement so far. The average particle size of the aggregate of the fumed silica primary particles was measured by LMS-24 manufactured by Seishin Enterprise Co., Ltd.

The fumed silica dispersion preferably has a silica concentration of 0.1 to 60% by weight, preferably 1 to 45% by weight, more preferably 10 to 30% by weight. If it is less than 0.1% by weight, the amount of water added as a dispersion medium becomes large, which may be economically disadvantageous in the drying step.
On the other hand, when it is more than 60% by weight, the fluidity of the dispersion liquid becomes extremely poor, and the mixing operation with other catalyst components may become difficult. The chemical properties of the fumed silica are not particularly limited, but those that are not hydrophobized are preferable because they are used in an aqueous dispersion medium.

As the aqueous dispersion medium, ion-exchanged water,
Distilled water or the like is used. Various stabilizers may be added for the purpose of stabilizing the finely dispersed state of the fumed silica. It is preferable to use ion-exchanged water or distilled water as it is because of the absence of impurities, the simplicity of the process, and the economical reason.

When the Mo-containing compound and the Si-containing compound are integrated in an aqueous system, the mixing molar ratio of the Mo-containing compound and the Si-containing compound is (the number of moles of Mo contained) / (content Molar number of Si) = 0.001-10
0 is preferable and 0.02 to 24 is preferable. When it is less than 0.001, the amount of Mo supplied as an integrated product obtained from the Mo-containing compound and the Si-containing compound in the composite oxide catalyst is small, and sufficient catalyst performance may not be obtained. On the other hand, if it is more than 100, the amount of Mo that does not integrate with the Si-containing compound increases, and it becomes difficult to obtain the sufficient effect of the present invention.

In the present invention, the mechanism of manifestation of improved catalyst performance is not clear, but since an aqueous dispersion in which a Mo-containing compound and a Si-containing compound are integrated in an aqueous system is used,
First, Mo is retained in the Si-containing compound. When a source compound of each component element other than Mo such as Co, Ni and Fe and Si is added thereto, Mo retained in Si is gradually released, and Mo such as Co, Ni and Fe described above is gradually released. And a precursor of a composite oxide composed of Mo and each of the constituent elements other than Si is homogeneously formed. When the composite oxide catalyst is formed by performing integration and heating with an aqueous system, the homogenized precursor also forms the composite oxide and becomes a constituent component of the catalyst. It is considered that this contributes to improvement of catalyst performance such as raw material conversion rate and selectivity.

Examples of the above complex oxide include complex oxides containing molybdenum, that is, complex oxides of molybdenum with various metals of each element other than Mo and Si. As a specific example, a composite oxide of Mo-Bi, Mo-
Co composite oxide, Mo-Ni composite oxide, Mo-F
e complex oxide, Mo-Mg complex oxide, Mo-Ca
Composite oxide, Mo-Zn composite oxide, Mo-Ce composite oxide, Mo-Sm composite oxide, Mo-Na composite oxide, Mo-K composite oxide, Mo-Rb composite oxide. Oxide, Mo-Cs complex oxide, Mo-Tl complex oxide, Mo-B complex oxide, Mo-P complex oxide, M
Examples thereof include complex oxides of o-As and complex oxides of Mo-W.

Next, a method for producing the above composite oxide catalyst will be described. The above-mentioned composite oxide catalyst is produced by a process including integration of a source compound of each component element constituting the composite oxide catalyst in an aqueous system and heating.

The following compounds can be mentioned as specific examples of the above-mentioned source compound. B as the above element
When i is used, examples of the source compound include bismuth nitrate, bismuth oxide, and bismuth subcarbonate.

Further, Na and X components (Mg, Ca, Zn,
It can also be supplied as bismuth subcarbonate in which at least one element selected from the group consisting of Ce and Sm) is dissolved. Bismuth subcarbonate in which Na is dissolved is
It can be produced by adding an aqueous solution of a water-soluble bismuth compound such as bismuth nitrate dropwise to an aqueous solution of sodium carbonate or sodium bicarbonate, and washing the resulting precipitate with water and drying. For the bismuth subcarbonate in which the X component is solid-dissolved, an aqueous solution of a water-soluble compound such as bismuth nitrate and a nitrate of the X component is dropped and mixed into an aqueous solution of ammonium carbonate or ammonium bicarbonate, and the obtained precipitate It can be produced by washing with water and drying. When sodium carbonate or sodium bicarbonate is used instead of the ammonium carbonate or ammonium bicarbonate,
It is possible to produce bismuth subcarbonate in which Na and the X component are solid-dissolved.

The Bi or the complex carbonate compound of Bi and Na or the like is preferably used in the form of powder. These compounds as a raw material for producing the catalyst may be in the form of particles larger than the powder, but considering the heating step for effecting the thermal diffusion, smaller particles are preferable, and smaller powders. Is more preferable. Therefore, when the above-mentioned Bi-Na complex carbonate compound is not in powder form, it is desirable to perform pulverization treatment before the heating step.

Further, when Na is used as the above-mentioned component element, its source compound is sodium nitrate,
Borax etc. can be mentioned. Further, as described above, it can be supplied after being solid-dissolved in bismuth subcarbonate. By using this complex carbonate compound of Bi and Na, the catalytic performance of the obtained complex oxide catalyst can be further improved.

When Fe is used as the above-mentioned component element, examples of the source compound thereof include ferric nitrate, ferric sulfate, ferric chloride and ferric acetate. When Co is used as the above-mentioned component element, as its source compound, cobalt nitrate, cobalt sulfate, cobalt chloride,
Examples include cobalt carbonate and cobalt acetate. When Ni is used as the above component element, examples of the source compound thereof include nickel nitrate, nickel sulfate, nickel chloride, nickel carbonate, nickel acetate and the like.

Further, as the above-mentioned component elements, the X component (Mg,
When at least one element selected from the group consisting of Ca, Zn, Ce and Sm) is used, its source compound is a nitrate compound, a sulfate compound, a chloride, a carbonate compound, acetic acid of those elements. Examples thereof include salt compounds. Further, as described above, it can be supplied after being solid-dissolved in bismuth subcarbonate.

When K is used as the above-mentioned component element, examples of the source compound thereof include potassium nitrate, potassium sulfate, potassium chloride, potassium carbonate, potassium acetate and the like. When Rb is used as the above component element, examples of the source compound thereof include rubidium nitrate, rubidium sulfate, rubidium chloride, rubidium carbonate, rubidium acetate and the like. When Cs is used as the above-mentioned component element, examples of the source compound thereof include cesium nitrate, cesium sulfate, cesium chloride, cesium carbonate, and cesium acetate. When Tl is used as the component element, examples of the source compound thereof include thallium nitrate, thallium chloride, thallium carbonate, thallium acetate and the like.

When B is used as the above component element, examples of the source compound thereof include borax, ammonium borate, boric acid and the like. When P is used as the above component element, examples of the source compound thereof include ammonium phosphomolybdate, ammonium phosphate, phosphoric acid, phosphorus pentoxide, and the like. When As is used as the above component element, examples of the source compound thereof include ammonium dialcseno octamolybdate, ammonium dialseno octatungstate, and the like. When W is used as the above component element, examples of the source compound thereof include ammonium paratungstate, tungsten trioxide, tungstic acid, phosphotungstic acid and the like.

As the Si source compound, the one described in the preparation of the above Mo / Si integrated aqueous dispersion is used. In addition to this aqueous dispersion, the above raw material compounds are added. You may use it.

Specific examples of the method for producing the composite oxide catalyst represented by the above general formula (1) are shown below. It is considered that those skilled in the art can easily extend from this specific example to other specific examples when the above-mentioned patent documents and the like are known.

First, for example, a Mo-containing compound such as ammonium paramolybdate and a Si-containing compound such as fumed silica are integrated in an aqueous system to produce a Mo / Si integrated dispersion. The fumed silica can be used as a fumed silica dispersion by suspending the fumed silica in an aqueous dispersion medium and subjecting the aggregated particles to a dispersion treatment as necessary. As the dispersion treatment method, as described above, a homogenizer,
Any of a dispersion method using a rotary shear flow such as a homomixer and a high shear blender, a dispersion method using an orifice contraction flow, and a dispersion method using ultrasonic waves may be adopted.

The above Mo / Si integrated dispersion is used as a source compound of Mo and Si, and if necessary, F
e, Co, Ni, Mg, Ca, Zn, Ce, Na, K,
Each source compound such as Rb, Cs, Tl, B, P, As, W, etc., for example the respective water-soluble salt is added. Then, the above-mentioned Bi source compound and Na source compound, preferably the complex carbonate compound of Bi and Na, is added.

Then, the obtained suspension or slurry is thoroughly stirred and then dried. The dried granules or cakes are heat-treated in the air in the temperature range of 250 to 350 ° C for a short time. The primary heat-treated product thus obtained is shaped into an arbitrary shape by a method such as extrusion molding, tablet molding, or carrier molding. Next, this molded body is subjected to a final heat treatment for about 1 to 16 hours, preferably at a temperature condition of 450 to 650 ° C. As a result, the composite oxide catalyst according to the present invention is manufactured.

When bismuth subcarbonate containing Na is used as the source compound of Bi and Na, iron, cobalt and nickel are already mixed with the acidic oxide in the primary heat-treated product obtained by the heat treatment for a short time. While forming a salt, most of the bismuth subcarbonate containing Na showed the morphology of the raw material. This means that the timing of adding the bismuth subcarbonate containing Na is not limited to before the heat treatment for a short time and may be after the heat treatment for a short time, and can be arbitrarily set. On the other hand, since the Mo / Si integrated aqueous dispersion is added as an aqueous dispersion at the time of addition, the effect is exerted by adding it in a step prior to the heat treatment for a short time.

The amount of each source compound added in the above production method may be set according to the composition ratio of the constituent elements of the composite oxide catalyst represented by the general formula (1).

The composite oxide catalyst produced by this method is
It can be used for various gas phase catalytic oxidation reactions carried out in the presence of molecular oxygen. Specific examples of the gas phase catalytic oxidation reaction here include, as described above, a reaction for producing acrolein or methacrolein from propylene, isobutene, tertiary butanol, or the like, acrylonitrile or methacrylonitrile in the presence of ammonia from propylene or isobutene. Examples thereof include a reaction for producing nitrile and a reaction for producing butadiene from butene.

[0048]

The present invention will be described in more detail below.
In the following, the definitions of propylene conversion, acrolein selectivity, acrylic acid selectivity, acrolein yield, acrylic acid yield, and total yield are as follows. Propylene conversion rate (mol%) = (mol number of reacted propylene / mol number of supplied propylene) × 100 Acrolein selectivity (mol%) = (mol number of acrolein produced / mol number of reacted propylene) × 100 ・ Acrylic acid selectivity (mol%) = (mol of generated acrylic acid / mol of reacted propylene) × 100 ・ Acrolein yield (mol%) = (mol of generated acrolein / supplied propylene) No. of mols) × 100 ・ Acrylic acid yield (mol%) = (moles of acrylic acid produced / moles of propylene fed) × 100 ・ Total yield (mol%) = acrolein yield (mol%) +
Acrylic acid yield (mol%)

(Example 1) 94.1 g of ammonium paramolybdate was dissolved in 400 ml of pure water by heating.
Next, 64 g of Aerosil (manufactured by Nippon Aerosil Co., Ltd.) was added to 256 ml of pure water and stirred. The two liquids were gradually mixed and sufficiently stirred until a pale yellow color was obtained to obtain an aqueous dispersion. Next, 8.97 g of ferric nitrate and cobalt nitrate 32.
3 g and nickel nitrate 32.3 g, ion-exchanged water 60
The solution was heated to ml to dissolve it, and was gradually mixed with the aqueous dispersion and stirred. To this mixed solution, a solution prepared by dissolving 1.69 g of borax and 0.45 g of potassium nitrate in 40 ml of ion-exchanged water with heating was added and sufficiently stirred. Next, 100 g of bismuth nitrate was dissolved in ion-exchanged water acidified with nitric acid. Further, 42.0 g of sodium carbonate was heated and dissolved in ion-exchanged water. The two liquids were gradually mixed with sufficient stirring. After mixing with stirring, the obtained white precipitate was washed, filtered and dried. The Na content of the obtained bismuth subcarbonate was 0.53% by weight. 0.53 of the above Na
34.7 g of white bismuth subcarbonate having a composite of wt% is added to the above mixed solution and mixed with stirring. Next, after heating and drying this slurry, it was subjected to heat treatment at 300 ° C./1 hour in an air atmosphere. The obtained granular solid is sized 5 with a compact molding machine.
mm into a tablet having a height of 4 mm, followed by calcination in a muffle furnace at 500 ° C. for 4 hours to obtain a catalyst. The composition ratio of the metal components of the catalyst calculated from the charged raw materials was as follows. Mo: Bi: Co: Ni: Fe: Na: B: K: Si =
12: 3: 2.5: 2.5: 0.5: 0.4: 0.4:
0.1: 24 20 ml of this catalyst was filled in a reaction tube with an inner diameter of 15 mm and made of a stainless steel niter jacket, and the propylene concentration was 10
%, Steam concentration 17% and air concentration 73% were passed through at atmospheric pressure for a contact time of 2.0 seconds to carry out the propylene oxidation reaction at a reaction temperature of 310 ° C. Was obtained. Propylene conversion 98.6% Acrolein selectivity 93.7% Acrolein yield 92.4% Acrylic acid selectivity 3.4% Acrylic acid yield 3.4% Total yield 95.8% (Comparative Example 1) Para Ammonium molybdate 94.1 g
Was heated and dissolved in 400 ml of ion-exchanged water. Next, 8.97 g of ferric nitrate, 32.3 g of cobalt nitrate and 32.3 g of nickel nitrate were heated and dissolved in 60 ml of ion-exchanged water. The two liquids were gradually mixed with sufficient stirring. To this mixed solution, a solution prepared by dissolving 1.69 g of borax and 0.45 g of potassium nitrate in 40 ml of ion-exchanged water with heating was added and sufficiently stirred. Next, Example 1
The white bismuth subcarbonate (58.1 g) containing 0.53% by weight of Na used in Step 2 was added, and 64 g of Aerosil (manufactured by Nippon Aerosil Co., Ltd.) was added to 256 ml of pure water. Next, after heating and drying this slurry, it was subjected to heat treatment at 300 ° C./1 hour in an air atmosphere. Using a compact molding machine, the obtained granular solid is 5 mm in diameter,
Tablet-molded into tablets with a height of 4 mm, then 5 in a muffle furnace
It was calcined at 00 ° C / 4 hours to obtain a catalyst. The composition ratio of the metal components of the catalyst calculated from the charged raw materials was as follows. Mo: Bi: Co: Ni: Fe: Na: B: K: Si =
12: 3: 2.5: 2.5: 0.5: 0.4: 0.4:
0.1: 24 20 ml of this catalyst was filled in a reaction tube with an inner diameter of 15 mm and made of a stainless steel niter jacket, and the propylene concentration was 10
%, Steam concentration 17% and air concentration 73% were passed through at atmospheric pressure for a contact time of 2.0 seconds to carry out the propylene oxidation reaction at a reaction temperature of 310 ° C. Was obtained. Propylene conversion 98.1% Acrolein selectivity 94.5% Acrolein yield 92.7% Acrylic acid selectivity 2.5% Acrylic acid yield 2.5% Total yield 95.2%

(Results) As is clear from the results of Example 1 and Comparative Example 1, the propylene conversion rate can be improved by about 0.5% by using the predetermined Mo / Si integrated dispersion. At the same time, the total acrolein selectivity and acrylic acid selectivity were improved by about 0.1%, and the total yield was improved by 0.6%.

[0051]

According to the present invention, since the composite oxide catalyst is produced by using the predetermined Mo / Si integrated dispersion liquid, it is possible to further improve the catalyst performance such as the raw material conversion rate and the selectivity.

Continuation of front page (51) Int.Cl. ⁷ identification code FI theme code (reference) C07C 51/25 C07C 51/25 57/05 57/05 // C07B 61/00 300 C07B 61/00 300 (72) Invention Towa Iwakura 1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Chemical Co., Ltd. F-term within the company (reference) 4G069 AA03 AA08 BA02A BA02B BB06A BB06B BC02B BC03B BC25B BC66B BC67B BC68B BD03B BD05B CB07 CB10 CB54 AC13 A04A02 4FB02 FB04 A02H BA19 BA20 BA21 BA30 BA33 BE30 BS10 4H039 CA65 CC30 CD10

Claims (10)

[Claims] 1. A molybdenum (Mo) source compound is used when a composite oxide catalyst containing at least Mo and Si is produced by a process including integration of a source compound of each component element in an aqueous system and heating. At least part of
A method for producing a composite oxide catalyst, which comprises using an aqueous dispersion obtained by integrating a Mo-containing compound and a silicon (Si) -containing compound in an aqueous system. 2. 10 to 100% by weight of Mo source compound
Is the aqueous dispersion, and the method for producing a composite oxide catalyst according to claim 1, wherein 3. The method for producing a composite oxide catalyst according to claim 1, wherein the Si-containing compound is fumed silica. 4. The method for producing a composite oxide catalyst according to claim 3, wherein the fumed silica has an average primary particle diameter of 15 to 50 nm. 5. The method for producing a composite oxide catalyst according to claim 1, further comprising a composite oxide containing Mo as a component constituting the composite oxide catalyst. 6. An essential component of the composite oxide catalyst,
The method for producing a composite oxide catalyst according to claim 1, comprising at least one of iron (Fe), cobalt (Co), and nickel (Ni). 7. An essential component of the composite oxide catalyst,
The method for producing a composite oxide catalyst according to claim 1, which contains bismuth (Bi). 8. The method for producing a complex oxide catalyst according to claim 7, wherein the source compound of Bi is bismuth subcarbonate or a complex carbonate compound of Bi and sodium (Na). 9. A gas phase catalytic oxidation reaction for producing acrolein or methacrolein from propylene, isobutene or tertiary butanol, a gas phase catalytic ammoxidation reaction for producing acrylonitrile or methacrylonitrile from propylene or isobutene, and butadiene from butene. A gas phase catalytic oxidative dehydrogenation reaction to be used for production, which is represented by the following general formula (1).
Or the method for producing the composite oxide catalyst according to item 8. Mo _a Bi _b Co _c Ni _d Fe _e Na _f X _g Y _h Z _i Si _j O _k (1) (where X is magnesium (Mg), calcium (C
a), zinc (Zn), cerium (Ce) or samarium (Sm), and at least one of Y is potassium (K), rubidium (Rb), cesium (Cs) or thallium (Tl). One kind, Z
Represents at least one of boron (B), phosphorus (P), arsenic (As) and tungsten (W). Also, a
To k represent atomic ratios of the respective elements, and when a = 12, b = 0.5 to 7, c = 0 to 10, d = 0 to 1
0, c + d = 1-10, e = 0.05-3, f = 0
1, g = 0 to 1, h = 0.04 to 0.4, i = 0 to 3,
j = 0.5 to 48, and k are values that satisfy the oxidation states of other elements. ) 10. A method for producing acrolein or acrylic acid from propylene as a raw material, which comprises using the composite oxide catalyst produced by the production method according to claim 1.