KR100492454B1 - Catalyst and its manufacturing method - Google Patents

Abstract

The present invention relates to a catalyst having high activity and high mechanical strength and a process for producing the same. The catalyst according to the invention comprises molybdenum, vanadium, copper and antimony as main components. X-ray diffraction analysis of the catalytically active component by Cu-Kα rays shows the maximum peak at 22.2 ± 0.3 ° (2θ).

Description

Catalyst and its preparation method

The present invention relates to a catalyst and a method for producing the same. In particular, the present invention relates to a catalyst suitable for the production of acrylic acid by the catalytic oxidation of acrolein to oxygen molecules in the gas phase and a process for the preparation thereof.

Catalysts for producing acrylic acid by catalytic oxidation of acrolein in the gas phase are described in Japanese Patent Publication Nos. 41-1775 (1996) and 44-12129 (1969).

Japanese Patent Application Laid-Open No. 47-8360 (1972) describes a catalyst containing antimony, molybdenum, vanadium and tungsten and trace amounts of copper as main components. In addition, Japanese Patent Application Laid-Open No. 48-96514 (1973) discloses a catalyst containing molybdenum, vanadium, tungsten and tin as the main components and optionally antimony and / or copper.

Japanese Patent Application Publication Nos. 51-11709 (1976), 52-23589 (1977), 52-153889 (1977), 58-166939 (1983), and 3-218334 (1991). In the arc, a catalyst comprising as an optional component copper, tin, antimony and chromium; A catalyst comprising an antimony-nickel compound; Coated catalyst comprising copper and antimony as optional components; Coated ring catalyst comprising copper and antimony as optional components; And high yield and high productivity catalysts. Some of these catalysts are made on a commercial scale and used for the production of acrylic acid, but their productivity is not always satisfactory. Recently, as the demand for acrylic acid increases, the demand for high productivity catalysts has increased.

Recently, increased amounts of acrolein supplied per unit volume of catalyst (“high load state”) have been used to enhance productivity in the production of acrylic acid by catalytic oxidation of acrolein in gas phase. Since the oxidation reaction of acrolein is exothermic, hot spots occur due to increased heat with increasing amounts of acrolein. These hot spots sometimes lead to the incorporation of molybdenum, which is most often used as a constituent of the catalytically active component.

If the catalyst used in this reaction is produced by compression, extrusion or coating, and the mechanical strength of the catalyst is low, the powder of the broken or peeled off catalytically active component can clog the reaction vessel when filled with the catalyst and the pressure in the reaction vessel This rises abnormally. Therefore, it is desirable for the compressed, extruded or coated catalyst to have good mechanical strength, such as wear resistance.

Summary of the Invention

The present inventors have studied to provide a catalyst that satisfies the above conditions and found a catalyst having higher activity at lower temperatures and having higher selectivity and higher mechanical strength (less wear) than the conventional one. . As a result, the present invention has been completed.

Accordingly, the present invention provides the following.

(1) a catalyst having a composition in which the catalytically active component is represented by the following general formula (1):

Mo ₁₂ V _a W _b Cu _C Sb _d X _e Y _f Z _g Oh (1)

In the above formula,

Mo, V, W, Cu, Sb and O represent molybdenum, vanadium, tungsten, copper, antimony and oxygen, respectively

X is at least one element selected from the group consisting of alkali metals and thallium,

Y is at least one element selected from the group consisting of magnesium, calcium, strontium, barium and zinc,

Z is at least one element selected from the group consisting of niobium, cerium, tin, chromium, manganese, iron, cobalt, samarium, germanium, titanium and arsenic,

a, b, c, d, e, f, g and h are 0 <a≤10, 0≤b≤10, 0 <c≤6, 0 <d≤10, 0≤e≤ based on 12 molybdenum atoms Atomic ratios of 0.5, 0 ≦ f ≦ 1, and 0 ≦ g <6;

h is the number of oxygen atoms required to satisfy the total valence,

In the X-ray diffraction analysis by the copper Kα ray of the catalytically active component, the maximum peak appears at 22.2 ± 0.3 ° (2θ: θ is the diffraction angle).

(2) a powder obtained by drying a metal element (hereinafter referred to as "catalytically active element") constituting a catalytically active component or an aqueous solution or dispersion containing the compound and then sintering the dried powder, the powder 5 g and pure water The electrical conductivity of the mixture of 75 g was 100-2,000 μs / cm as measured after stirring for 5 minutes, the catalyst according to (1) above;

(3) the catalyst according to the above (2), wherein the dry powder is obtained by spray drying;

(4) The catalyst according to the above (3), wherein an aqueous solution or dispersion containing a catalytically active element or a compound thereof is obtained by mixing antimony trioxide and water as an antimony source;

(5) a catalyst obtained by compressing, extruding or coating the catalyst according to any one of (1) to (4), wherein the catalyst has a diameter of 0.01 to 0.1 µm, 0.1 to 1 µm, 1 to 10 µm and 10 to 200 µm The pore volume is less than 20%, less than 30%, more than 40% and less than 50%, respectively, based on the total volume of pores having a diameter of 0.01-200 μm in the catalyst;

(6) the catalyst according to any one of (1) to (5) above for use in the production of acrylic acid by catalytic oxidation of acrolein to oxygen molecules in the gas phase;

(7) a process for producing a catalyst according to any one of (1) to (6), comprising the following steps;

(a) drying an aqueous solution or dispersion containing the catalytically active element or a compound thereof to provide a dried powder,

(b) sintering the dry powder obtained in step (a) to obtain a catalytically active ingredient powder, and

(c) coating the carrier with the catalytically active ingredient powder obtained in step (b) using a tumble granulator;

(8) the process according to (7) above, wherein the reinforcing material is used in step (c) with the powder of the catalytically active component;

(9) the process according to (7) or (8) above, wherein the binder is used in step (c) with a powder of the catalytically active component;

(10) the method according to the above (9), wherein the binder is a diol or a triol;

(11) The method according to the above (10), wherein the triol is glycerin; And

(12) The method according to the above (8), wherein the reinforcing material is ceramic fiber.

1 shows an X-ray diffraction graph of the pre-sintered granules obtained in Example 1,

2 shows an X-ray diffraction graph of the catalyst obtained in Example 1. FIG.

In the accompanying drawings, the abscissa and ordinate represent 2θ and cps, respectively.

In the catalyst of the present invention, the atomic ratio of each element in the catalytically active component represented by the general formula (1) is as described above, preferably 2≤a≤5, 0.2≤b≤2, 0.2≤c≤4, 0.3 ≦ d ≦ 5, 0 ≦ e ≦ 0.2, 0 ≦ f ≦ 0.5, and 0 ≦ g ≦ 3.

The catalyst of the present invention can be prepared by drying a metal element constituting the catalytically active component or an aqueous solution or dispersion containing the compound, sintering the dried powder and then optionally molding the sintered powder.

The compound of the catalytically active element used in the present invention is not particularly limited as long as it can be converted into an oxide upon sintering, and there are chlorides, sulfates, nitrates, ammonium salts and oxides of catalytically active elements. Examples of compounds that can be used include molybdenum trioxide and molybdic acid or salts thereof as the molybdenum compound; Vanadium compounds as vanadium pentoxide, vanadil sulfate and vanadium acid or salts thereof; Tungstic acid or salts thereof as tungsten compound; Copper compounds include copper oxide, copper sulfate, copper nitrate and copper molybdate. Examples of antimony compounds that can be used include antimony trioxide, antimony pentoxide, antimony acetate and antimony trichloride. Among these antimony compounds, antimony trioxide is preferred, which is preferably used without chemical treatment. This means that no chemical treatment is used to facilitate the decomposition or dispersion of antimony trioxide to water, such as by contacting antimony trioxide with an acid such as nitric acid or sulfuric acid, an oxidizing agent such as hydrogen peroxide, or an alkali. Antimony trioxide is preferably used in the form of a fine powder.

The compounds of the catalytically active element may be used alone or in a mixture of two or more compounds.

In the preparation of the catalyst according to the invention, an aqueous solution or dispersion containing catalytically active elements or their compounds is first prepared. This aqueous solution or dispersion is hereinafter simply referred to as "slurry solution" unless otherwise specified. According to the invention, the slurry solution is preferably an aqueous solution. The content of each catalytically active element or its compound in the slurry solution is not particularly limited as long as the atomic ratio of each catalytically active element is within the range specified above. The amount of water used is not particularly limited, but all elements and / or compounds may be completely dissolved or evenly mixed. The amount of water may be appropriately determined in consideration of the following drying step and temperature, and usually 200 to 2,000 parts by weight based on 100 parts by weight of the total compound. If the amount of water is too small, all compounds may not be completely dissolved or evenly mixed. Too much water can increase the energy cost of the drying step or cause problems such as incomplete drying.

The homogeneously mixed slurry solution is then dried. The drying method is not particularly limited as long as the slurry solution can be dried and a powder product can be obtained, such as drum, freeze spray drying. In the present invention, spray drying is preferred among these methods because the slurry solution is dried in a powder state in a short time. The drying temperature may vary depending on the concentration and the feed rate of the slurry solution and the temperature at the outlet of the dryer is generally 85-130 ° C. Preferably, it is dried so that the average particle diameter of the dried powder may be 20-60 micrometers.

The catalyst of the present invention can be obtained by sintering the dried powder at 200 to 600 ° C. for 1 to 15 hours and then optionally grinding the sintered powder, which is preferably molded by the following method. When the molding step is carried out, the sintering is preferably carried out in two steps: presintering before the molding step and post sintering after the molding step. Any known method may be used as the sintering method, and is not particularly limited.

The process for producing the catalyst using the shaping step is carried out as follows. Presintering is generally carried out at 250 to 500 ° C., preferably at 300 to 450 ° C. for 1 to 15 hours, preferably for 3 to 6 hours. The presintering step prevents deterioration and flaking of the catalytically active component when the fully formed catalyst is filled into the reaction vessel. That is, the wear of the molded catalyst is less.

Such pre-sintered granules (hereinafter referred to as "pre-sintered granules") are molded directly or optionally after grinding. Pre-sintered granules having an electrical conductivity of 100-2,000 μs / cm, preferably 500-1,500 μs / cm, as measured after stirring a mixture of 5 g of granules or powder and 75 g of pure water for 5 minutes at 0-15 ° C. Or optionally using a ground powder, a high performance catalyst with very high activity and low wear is obtained.

Catalysts having high catalytic activity are obtained by presintering as follows. Preferably, however, the pre-sintered granules are used after molding. In molding, the pre-sintered granules, optionally mixed with a binder, are (A) compressed; (B) is mixed with a molding aid, such as silica gel, diatomaceous earth or alumina powder, and then extruded into a spherical or cyclic shape; Or (C) a spherical carrier such as silicon carbide, alumina, mullite or alanderm having a diameter of 2.5 to 10 mm by tumble granulation or the like.

Binders used include water, high molecular weight binders such as ethanol, polyvinyl alcohol, and inorganic binders such as water soluble silica sol solutions. Alcohols comprising diols such as ethylene glycol and triols such as glycerin are preferably used, with glycerin being particularly preferred. Alcohol can be used directly, but aqueous alcohol solutions with a concentration of at least 10% by weight are effective for providing high performance catalysts.

The amount of binder used is generally 10 to 50 parts by weight based on 100 parts by weight of the presintered granules.

Optionally, molding aids such as silica gel, diatomaceous earth, or alumina powder may also be used. The amount of molding aid used is generally 5 to 60 parts by weight based on 100 parts by weight of presintered granules. In addition, reinforcements such as ceramic fibers or whiskers are useful for enhancing the mechanical strength of the catalyst. However, fibers such as carium titanate whiskers and basic magnesium carbonate whiskers are undesirable because they are reactive with catalyst components. The amount of fibers used is generally 1-30 parts by weight, based on 100 parts by weight of the pre-sintered granules.

When molding aids and reinforcements are used, they are generally mixed with the pre-sintered granules. The binder may be mixed with the pre-sintered granules or added to the molding machine before, or simultaneously with, the addition of the pre-sintered granules.

Among the molding methods, tumble granulation (C) is preferred as described above. For example, the carrier is added to a device having a stationary container and a flat or non-uniform disk provided at the bottom of the container. The carrier is vigorously stirred in repeated rotation and rotation as the disk is rotated at high speed. The carrier is covered with the mixture by the addition of a binder, presintered granules, and optional molding aid and reinforcement. The binder is (1) premixed with the mixture, (2) added to a stationary vessel simultaneously with the addition of the mixture, (3) added after the addition of the mixture, or (4) added before the addition of the mixture; Or (5) divide both the binder and the mixture into two or more portions and add those portions in any combination of (2) to (4) above. In method 5, it is preferable to use an automatic feeder to control the rate of addition, so that no mixture is attached to the vessel wall or no agglomerates of the mixture are formed.

Examples of carriers that can be used in method (C) include spherical carriers having a diameter of 2.5 to 10 mm, such as silicon carbide, alumina, mullite and alandeum. Among these carriers, those having a porosity of 30 to 50% and an absorption of 10 to 30% are preferably used. The carrier is generally used in a ratio of 10 to 75% by weight, preferably 15 to 50% by weight, of the presintered granules and the total weight of the carrier.

The molded article of the pre-sintered granules obtained by the above methods (A) to (C) preferably has a diameter of 2 to 10 mm and a height of 3 to 20 mm in the case of a cylindrical shape, and preferably has a diameter of 3 to 15 mm in the case of a spherical shape. Do.

The catalyst can be obtained by post sintering molded articles of presintered granules. Post-sintering is generally performed at 250-500 degreeC, Preferably it is 300 to 450 degreeC for 1 to 50 hours. According to the invention, the molded article obtained by post sintering (hereinafter referred to as "molding catalyst") exhibits a maximum peak at 22.2 ± 0.3 ° (2θ) in X-ray diffraction analysis by Cu-Kα rays of the catalytically active component, The intensity of this maximum peak is at least the same as that of the other peaks, preferably 1.6 times or more, more preferably 2 times or more, and most preferably 4 times or more. The symbol "2θ" in the present specification means a double value of the diffraction angle (θ) in the X-ray diffraction analysis. Other peaks appear at 2θ values other than 22.2 ± 0.3 °, as well as peaks from molybdenum oxide as described in American Society for Testing Material (ASTM) cards 5-508, 21-569, 35-609, and 37-1445. But may also include peaks resulting from compounds in which molybdenum oxide is partially replaced by a compound of the catalytically active element of the present invention, for example at least one of vanadium, tungsten and antimony and the catalytically active element used as starting material. In X-ray diffraction analysis of the molding catalyst, the maximum peak can often arise from alumina used as a carrier or optional reinforcement. These peaks are not considered in the present invention. In order to obtain a shaped catalyst having a special X-ray diffraction pattern as described above, it is preferable to use presintered granules which exhibit the same properties as those obtained after post sintering in X-ray diffraction analysis in the same manner.

In the molded catalyst according to the present invention, the total volume of pores having a diameter of 0.01 to 200 μm is 0.01 to 1.0 ml / g, preferably 0.01 to 0.4 ml / g, and the specific surface area is 0.5 to 10 m ² / g, preferably It is preferable that it is 1.0-5.0 m <^2> / g below. The pore distribution is 20% or less based on the total volume of the pores having a diameter of 0.01 to 0.1 μm, 0.1 to 1 μm, 1 to 10 μm, and 10 to 200 μm, respectively, of the pores having a diameter of 0.01 to 200 μm in the catalyst. 30% or less, 40% or more, and 50% or less.

The catalyst of the present invention has higher activity and higher selectivity of acrylic acid at lower temperatures compared to the conventional one and thus can be used even in reactions under high load conditions. In addition, the catalyst has good wear resistance and very good commercial value.

The invention is described in more detail in the following examples and comparative examples, but the invention is not limited to the following examples without departing from the spirit of the appended claims.

In the following examples and comparative examples, all parts are parts by weight, and the acrolein conversion (mol%), acrylic acid selectivity (mol%) and acrylic acid yield (%) are respectively defined by the following formulas (2) to (4):

(2) acrolein conversion (mol%) =

    100 X (moles of reacted acrolein) / (moles of supplied acrolein)

(3) acrylic acid selectivity (mol%) =

    100 X (moles of generated acrylic acid) / (moles of converted acrolein)

(4) acrylic acid yield (%) =

    100 X (moles of generated acrylic acid) / (moles of supplied acrolein)

X-ray diffraction was measured using JDX-7F (manufactured by JEOL LTD.) Or RINT-1100V (manufactured by RIGAKU).

Pore distribution was measured using a mercury pore meter Poresizer 9320 (manufactured by MICROMERITICS).

Abrasion resistance was measured by a wear resistance tester (manufactured by KAYAGAKI IRIKA KOGYO). The catalyst sample was spun at 25 rpm for 10 minutes and then passed through a 2.36 mm standard sieve. The weight of the catalyst remaining in the sieve was measured, and the wear resistance (% by weight) was determined by the following equation (5):

(5) Wear resistance (% by weight) =

    100 X (weight of catalyst remaining in sample weight-2.36 mm sieve) / (sample weight)

Electrical conductivity was determined by dispersing 5 g of sample in 75 g of pure water, stirring for 5 minutes, and then measuring the conductivity with CM-20S (manufactured by TOA Electonics Ltd.).

Example 1

600 parts of deionized water and 16.26 parts of ammonium tungstate were added and stirred to the mixing tank A with a stirring motor. Then, 18.22 g of ammonium metavanadate and 110 parts of ammonium molybdate were dissolved. Furthermore, 3.78 parts of antimony trioxide powder was added. After dissolving 15.56 parts of copper sulfate in the mixing tank (B) containing 96 parts of deionized water, the solution was added to the mixing tank (A) to form a slurry solution. The slurry solution was dried in a spray dryer while controlling the feed rate such that the temperature at the outlet of the dryer was about 100 ° C. The resulting granules were placed in a furnace at room temperature and the furnace temperature was raised at a rate of about 60 ° C. per hour. The granules were then presintered at 390 ° C. for about 5 hours. In the X-ray diffraction analysis of the pre-sintered granules, 2θ values were measured, and the maximum peak at 22.2 ° and the second largest peak at 27.0 ° were observed when the intensity ratio was 100: 23. Fig. 1 shows the measurement results of the 2θ values in the X-ray diffraction analysis.

The presintered granules were ground in a ball mill to obtain a powder (hereinafter referred to as "presintered powder"). The electrical conductivity of the presintered powder is 1050 μs / cm. In the tumble granulator, 12 parts of presintered powder were applied to 36 parts of an alandom carrier having a porosity of 40%, an absorption of 19.8%, and a diameter of 4 mm while spraying 2.4 parts of 20% by weight aqueous solution of glycerin on the carrier. As a result, the molded product was placed in a furnace at room temperature and the temperature was raised at a rate of about 70 ° C per hour. The product was then sintered (post sintered) at 390 ° C. for 5 hours to obtain the catalyst of the invention. The catalytically active component except for oxygen in the catalyst of the present invention has the following elemental composition:

Mo ₁₂ V ₃ W _1.2 Cu _1.2 Sb _0.5

X-ray diffraction analysis was performed on the catalyst. The peaks from the alanthanum carrier were observed, but the other peaks were nearly identical to those observed in the presintered granules. The measurement result of 2θ value in X-ray diffraction analysis is shown in FIG.

The pore distribution of the catalyst was measured. The volume of pores having a diameter of 0.01 to 0.1 μm, 0.1 to 1 μm, 1 to 10 μm and 10 to 200 μm is 7%, respectively, based on the total volume of pores having a diameter of 0.01 to 200 μm in the catalyst having 0.09 ml / g, 7%, 64% and 22%.

The catalyst had a wear resistance of 0.3% by weight and a specific surface area of 2.2 m ² / g.

In a reaction vessel having an internal diameter of 21.4 mm, 30 ml of catalyst was placed and a gas reaction mixture was supplied at 1800 SV per hour [space velocity = (volume of gas per unit time) / (volume of charged catalyst)]. The reaction mixture was obtained by the catalytic oxidation of propylene in a gas phase supplemented with oxygen and nitrogen using a molybdenum-bismuth catalyst. The composition of this mixture was as follows:

The reaction results are shown in Table 1.

Example 2

In the tumble granulator, 24 parts of the presintered powder obtained in Example 1 were applied to 36 parts of an alandom carrier having a porosity of 34%, an absorption of 17%, and a diameter of 3.5 mm with 3 parts of a 20% by weight aqueous solution of glycerin on the carrier. The resulting molded article was placed in a furnace at room temperature and the temperature was raised at a rate of about 70 ° C per hour. The product was then sintered at 390 ° C. for 5 hours to obtain the catalyst of the present invention. The catalytically active component except for oxygen in the catalyst of the present invention has the following elemental composition:

Mo ₁₂ V ₃ W _1.2 Cu _1.2 Sb _0.5

The pore distribution of the catalyst was measured. The volume of pores having a diameter of 0.01 to 0.1 μm, 0.1 to 1 μm, 1 to 10 μm, and 10 to 200 μm was 10%, 9%, and 63, respectively, based on the total volume of the pores having a diameter of 0.01 to 200 μm in the catalyst. % And 18%. The catalyst had abrasion resistance of 0.5% by weight and a specific surface area of 3.5 m ² / g.

The catalyst was reacted as in Example 1 and the results are shown in Table 1.

Examples 3-6

The same procedure as in Example 1 was repeated except that 5.19 parts, 10.37 parts, 23.33 parts and 32.40 parts of copper sulfate were used in Examples 3 to 6, respectively. The composition of the catalytically active component excluding oxygen in the catalyst of the present invention was as follows:

X-ray diffraction analysis was performed on the catalytically active component of the catalyst and the 2θ values were measured. In each catalyst, the maximum peak was observed at 22.2 °, which is a feature of the present invention. However, the inherent peaks of molybdenum oxide are very wide and overlap each other. As a result, no sharp peaks were observed. The electrical conductivity of the presintered powders used in these examples was 200-1400 μs / cm. Moreover, the wear resistance of this catalyst was 0.5% or less.

The catalyst was reacted as in Example 1. The results are shown in Table 1.

TABLE 1

Examples 7-10

The same procedure as in Example 1 was repeated except that 2.27 parts, 7.56 parts, 15.13 parts and 22.70 parts of antimony trioxide were used in Examples 7 to 10, respectively. The composition of the catalytically active component excluding oxygen in the catalyst of the present invention was as follows:

X-ray diffraction analysis was performed on the catalytically active component of the catalyst and the 2θ values were measured. In each catalyst, the maximum peak was observed at 22.2 °, which is a feature of the present invention. However, the inherent peaks of molybdenum oxide are very wide and overlap each other. As a result, no sharp peaks were observed. The electrical conductivity of the presintered powders used in these examples was 150-1200 μs / cm. Wear resistance of this catalyst was 0.6% or less.

The catalyst was reacted as in Example 1. The results are shown in Table 2.

Example 11

600 parts of deionized water and 16.26 parts of ammonium tungstate were added and stirred to the mixing tank A with a stirring motor. Then, 18.22 parts of ammonium metavanadate and 110 parts of ammonium molybdate were dissolved. Furthermore, 3.78 parts of antimony trioxide powder was added. After dissolving 15.56 parts of copper sulfate and 1.05 parts of potassium nitrate in the mixing tank (B) containing 96 parts of deionized water, the solution was added to the mixing tank (A) to form a slurry solution.

The slurry solution was dried in a spray dryer while controlling the feed rate so that the outlet temperature of the dryer was about 100 ° C. The resulting granules were placed in a furnace at room temperature and the furnace temperature was raised at a rate of about 60 ° C. per hour. The granules were then sintered at 390 ° C. for about 5 hours to obtain presintered granules.

In a tumble granulator, 12 parts of pre-sintered powder obtained by pulverizing the pre-sintered granules in a ball mill were applied to 36 parts of an alandom carrier having a diameter of 4 mm while sprinkling 2.4 parts of 20% by weight aqueous solution of glycerin on the carrier. The resulting molded article was placed in a furnace at room temperature and the temperature was raised at a rate of about 70 ° C per hour. The product was then sintered at 390 ° C. for 5 hours to obtain the catalyst of the present invention. The catalytically active component except for oxygen in the catalyst of the present invention has the following elemental composition:

Mo ₁₂ V ₃ W _1.2 Cu _1.2 Sb _0.5 K _0.2

X-ray diffraction analysis of the presintered granules used showed that the maximum value was observed at 22.2 ° and the second largest peak at 26.7 °, where the intensity ratio was 100: 28. Similar results were obtained for.

The pore distribution of the catalyst was measured. The volume of pores having a diameter of 0.01 to 0.1 μm, 0.1 to 1 μm, 1 to 10 μm, and 10 to 200 μm is 9%, 6%, and 73%, respectively, based on the total volume of pores having a diameter of 0.01 to 200 μm in the catalyst. And 12%. The wear resistance of the catalyst was 0.3% by weight and the specific surface area was 1.8 m ² / g.

The catalyst was reacted as in Example 1. The results are shown in Table 2.

Example 12

The same procedure as in Example 11 was repeated except that 2.45 parts of calcium nitrate was used instead of potassium nitrate. The composition of the catalytically active component excluding oxygen in the catalyst of the present invention was as follows:

Mo ₁₂ V ₃ W _1.2 Cu _1.2 Sb _0.5 Ca _0.2

X-ray diffraction analysis of the presintered granules used showed that the 2θ value was the largest peak at 22.2 ° and the second largest peak at 27.3 °, where the intensity ratio was 100: 36. Similar results were obtained for the catalytically active components of the catalysts according to the invention.

The catalyst was reacted as in Example 1. The results are shown in Table 2.

Example 13

600 parts of deionized water and 16.26 parts of ammonium tungstate were added and stirred to the mixing tank A with a stirring motor. Then, 18.22 parts of ammonium metavanadate and 110 parts of ammonium molybdate were dissolved. Furthermore, 3.78 parts of antimony trioxide powder was added. After 20 minutes, 4.47 parts of cerium oxide was added. After dissolving 15.05 parts of copper nitrate in the mixing tank (B) containing 96 parts of deionized water, the solution was added to the mixing tank (A) to form a slurry solution.

The slurry solution was dried in a spray dryer while controlling the feed rate so that the outlet temperature of the dryer was about 100 ° C. The resulting granules were placed in a furnace at room temperature and the furnace temperature was raised at a rate of about 60 ° C. per hour. The granules were then presintered at 370 ° C. for about 5 hours to obtain presintered granules.

In a tumble granulator, 12 parts of pre-sintered powder obtained by pulverizing the presintered granules in a ball mill were applied to 36 parts of an alandom carrier having a diameter of 4 mm while sprinkling 2.4 parts of 20% by weight aqueous solution of glycerin on the carrier. The resulting molded article was placed in a furnace at room temperature and the temperature was raised at a rate of about 70 ° C per hour. The product was then sintered at 370 ° C. for 5 hours to obtain the catalyst of the present invention. The catalytically active component except for oxygen in the catalyst of the present invention has the following elemental composition:

Mo ₁₂ V ₃ W _1.2 Cu _1.2 Sb _0.5 Ce _0.5

X-ray diffraction analysis of the presintered granules used showed that the 2θ value was the largest peak at 22.2 ° and the second largest peak at 28.5 °, with an intensity ratio of 100: 34. Similar results were obtained for the catalytically active component of the catalyst.

The pore distribution of the catalyst was measured. The volume of pores having a diameter of 0.01 to 0.1 μm, 0.1 to 1 μm, 1 to 10 μm and 10 to 200 μm is 13%, 6% and 69%, respectively, based on the total volume of pores having a diameter of 0.01 to 200 μm in the catalyst. And 12%. The wear resistance of the catalyst was 0.3% by weight and the specific surface area was 2.0 m ² / g.

The catalyst was reacted as in Example 1. The results are shown in Table 2.

TABLE 2

Example 14

The same procedure as in Example 13 was repeated except that 3.45 parts of niobium oxide was used instead of cerium oxide. The composition of the catalytically active component excluding oxygen in the catalyst of the present invention was as follows:

Mo ₁₂ V ₃ W _1.2 Cu _1.2 Sb _0.5 Nb _0.5

X-ray diffraction analysis of the presintered granules used showed that the maximum value at 22.2 ° and the second largest peak at 22.6 ° were observed when the 2θ value was measured. Small peaks of niobium oxide were also observed. Similar results were obtained for the catalytically active components of the catalysts according to the invention.

The catalyst was reacted as in Example 1. The results are shown in Table 3.

Example 15

600 parts of deionized water and 16.26 parts of ammonium tungstate were added and stirred to the mixing tank A with a stirring motor. Then, 18.22 parts of ammonium metavanadate and 110 parts of ammonium molybdate were dissolved. Furthermore, 3.78 parts of antimony trioxide powder was added. After dissolving 15.56 parts of copper sulfate, 0.52 parts of potassium nitrate, and 2.66 parts of magnesium nitrate in a mixing tank (B) containing 96 parts of deionized water, the solution was added to the mixing tank (A) to form a slurry solution.

Then, the procedure of Example 11 was repeated to obtain the catalyst of the present invention. The catalytically active component except for oxygen in the catalyst of the present invention has the following elemental composition:

Mo ₁₂ V ₃ W _1.2 Cu _1.2 Sb _0.5 K _0.1 Mg _0.2

X-ray diffraction analysis of the presintered granules used showed that the 2θ value was the largest peak at 22.2 ° and the second largest peak at 27.3 °, where the intensity ratio was 100: 41. Similar results were obtained for the catalytically active component of the catalyst.

The pore distribution of the catalyst was measured. The volume of pores having a diameter of 0.01 to 0.1 μm, 0.1 to 1 μm, 1 to 10 μm and 10 to 200 μm is 7%, 5% and 80%, respectively, based on the total volume of pores having a diameter of 0.01 to 200 μm in the catalyst. And 8%. The wear resistance of the catalyst was 0.6% by weight and the specific surface area was 1.5 m ² / g.

The catalyst was reacted as in Example 1. The results are shown in Table 3.

Example 16

600 parts of deionized water and 16.26 parts of ammonium tungstate were added and stirred to the mixing tank A with a stirring motor. Then, 18.22 parts of ammonium metavanadate and 110 parts of ammonium molybdate were dissolved. Furthermore, 3.78 parts of antimony trioxide powder was added. After 20 minutes, 1.56 parts of tin oxide was added. After dissolving 15.56 parts of copper sulfate, 0.22 parts of sodium nitrate, and 1.10 parts of strontium nitrate in a mixing tank (B) containing 96 parts of deionized water, the solution was added to the mixing tank (A) to form a slurry solution.

Then, the procedure of Example 11 was repeated to obtain the catalyst of the present invention. The catalytically active component except for oxygen in the catalyst of the present invention has the following elemental composition:

Mo ₁₂ V ₃ W _1.2 Cu _1.2 Sb _0.5 Na _0.05 Sr _0.1 Sn _0.2

X-ray diffraction analysis of the pre-sintered granules used showed a peak at 22.2 °, which is a characteristic of the present invention. However, little inherent peak of molybdenum oxide was observed at 23 to 29 °. Similar results were obtained for the catalytically active component of the catalyst.

The catalyst was reacted as in Example 1. The results are shown in Table 3.

Examples 17 and 18

The same procedure as in Example 1 was repeated except that 12.15 parts and 24.3 parts of ammonium metavanadate were used in Examples 17 and 18, respectively. The composition of the catalytically active component excluding oxygen in the catalyst of the present invention was as follows:

Example 17 Mo ₁₂ V ₂ W _1.2 Cu _1.2 Sb _0.5

Example 18 Mo ₁₂ V ₄ W _1.2 Cu _1.2 Sb _0.5

X-ray diffraction analysis of the presintered granules used was carried out and 2θ values were measured. In each catalyst, a peak was observed at 22.2 °, which is a feature of the present invention. However, inherent peaks of molybdenum oxide were hardly observed at 23 to 29 degrees. Similar results were obtained for the catalytically active component of the catalyst.

The catalyst was reacted as in Example 1. The results are shown in Table 3.

Examples 19 and 20

The same procedure as in Example 1 was repeated except that 6.78 parts and 27.11 parts of ammonium tungstate were used in Examples 19 and 20, respectively. The composition of the catalytically active component excluding oxygen in the catalyst of the present invention was as follows:

Example 19 Mo ₁₂ V ₃ W _0.5 Cu _1.2 Sb _0.5

Example 20 Mo ₁₂ V ₃ W _2.0 Cu _1.2 Sb _0.5

X-ray diffraction analysis of the presintered granules used was carried out and 2θ values were measured. In the catalyst of Example 19, a peak was observed at 22.1 °, which is a feature of the present invention, while no inherent peak of molybdenum oxide was observed. Likewise, in the catalyst of Example 20, a peak was observed at 22.2 °, which is a feature of the present invention, while no inherent peak of molybdenum oxide was observed. Similar results were obtained for the catalytically active component of the catalyst.

The catalyst was reacted as in Example 1. The results are shown in Table 3.

TABLE 3

Example 21

The same procedure as in Example 1 was repeated except that the molded article obtained in Example 1 was sintered at 440 ° C. for about 2.5 hours. The composition of the catalytically active component excluding oxygen in the catalyst of the present invention was as follows;

Mo ₁₂ V ₃ W _1.2 Sb _0.5 Cu _1.2

X-ray diffraction analysis of the catalytically active component of the catalyst showed that the peak value at 22.2 ° and the second largest peak at 23.3 ° showed an intensity ratio of 100: 41. The wear resistance of the catalyst was 0.4% by weight.

The catalyst was reacted as in Example 1. The results are shown in Table 4.

Example 22

The same procedure as in Example 1 was repeated except that the molded article obtained in Example 1 was sintered at 480 ° C. for about 1 hour. The composition of the catalytically active component excluding oxygen in the catalyst of the present invention was as follows:

Mo ₁₂ V ₃ W _1.2 Cu _1.2 Sb _0.5

X-ray diffraction analysis of the catalytically active component of the catalyst showed that the peak value at 22.2 ° and the second largest peak at 23.0 ° showed an intensity ratio of 100: 60. The wear resistance of the catalyst was 0.3% by weight.

The catalyst was reacted as in Example 1. The results are shown in Table 4.

Example 23

The same procedure as in Example 1 was repeated except that the presintered powder obtained in Example 1 was molded using a 30 wt% aqueous solution of ethylene glycol as a binder. X-ray diffraction analysis was performed on the catalyst. Although several peaks of alumina based on alandeum carriers were observed, the other peaks were similar to those observed for presintered granules.

The pore distribution of the catalyst was measured. The volume of pores having a diameter of 0.01 to 0.1 μm, 0.1 to 1 μm, 1 to 10 μm and 10 to 200 μm is 11%, 10% and 67%, respectively, based on the total volume of pores having a diameter of 0.01 to 200 μm in the catalyst. And 12%. The wear resistance of the catalyst was 0.6% by weight and the specific surface area was 2.2 m ² / g.

The catalyst was reacted as in Example 1. The results are shown in Table 4.

Example 24

24 parts of the presintered powder obtained in Example 1 were mixed with 1.2 parts of silica-alumina having an average fiber length of 100 μm and an average fiber diameter of 2.0 μm. In the tumble granulator, the mixture was applied to 34.8 parts of an alandom carrier having a porosity of 34%, a water absorption of 17%, and a diameter of 3.5 mm while sprinkling 3 parts of a 20% by weight aqueous solution of glycerin on the carrier. The furnace was sintered at 390 ° C. for 2.5 hours while raising the temperature at room temperature at a rate of about 70 ° C. per hour to obtain a catalyst.

The pore distribution of the catalyst was measured. The volume of pores having a diameter of 0.1 to 10 μm, 1 to 10 μm and 10 to 200 μm was 11%, 72% and 17%, respectively, based on the total volume of pores having a diameter of 0.01 to 200 μm in the catalyst. The wear resistance of the catalyst was 0.1% by weight.

The catalyst was reacted as in Example 1. The results are shown in Table 4.

Example 25

23 parts of the pre-sintered powder obtained in Example 1, 1 part of silicon carbide whisker, 5 parts of 20% by weight aqueous solution of glycerin and 34 parts of porosity, 17 parts of water absorption and 66 parts of alanthanum carrier having a diameter of 3.5 mm are used. The catalyst of the present invention was obtained by repeating the same procedure as in Example 24 except for the above.

The pore distribution of the catalyst was measured. The volumes of pores having 0.1-1 μm, 1-10 μm and 10-200 μm in diameter were 15%, 73% and 12%, respectively, based on the total volume of pores having a diameter of 0.01-200 μm in the catalyst. The wear resistance of the catalyst was 0.2% by weight.

The catalyst was reacted as in Example 1. The results are shown in Table 4.

TABLE 4

Comparative Example 1

The catalyst was obtained by repeating the same procedure as in Example 1 except that antimony trioxide was not used. The composition of the catalytically active component excluding oxygen in the catalyst of the present invention was as follows:

Mo ₁₂ V ₃ W _1.2 Cu _1.2

The catalyst was reacted as in Example 1. The results are shown in Table 5.

Comparative Example 2

The catalyst was obtained by repeating the same procedure as in Example 1 except that copper oxide was not used. The composition of the catalytically active component excluding oxygen in the catalyst of the present invention was as follows:

Mo ₁₂ V ₃ W _1.2 Sb _0.5

The catalyst was reacted as in Example 1. The results are shown in Table 5.

TABLE 5

From the above results, it can be seen that the catalyst of the present invention exhibits higher reaction selectivity at about 10 to 70 ° C. than the conventional catalyst.

Background of the Invention

Claims (12)

The catalytically active component has a composition represented by the following general formula (1); Where Mo, V, W, Cu, Sb and O represent molybdenum, vanadium, tungsten, copper, antimony and oxygen, respectively X is at least one element selected from the group consisting of alkali metals and thallium, Y is at least one element selected from the group consisting of magnesium, calcium, strontium, barium and zinc, Z is at least one element selected from the group consisting of niobium, cerium, tin, chromium, manganese, iron, cobalt, samarium, germanium, titanium and arsenic, a, b, c, d, e, f, g and h are 0 <a≤10, 0≤b≤10, 0 <c≤6, 0 <d≤10, 0≤e≤ based on 12 molybdenum atoms Atomic ratios of 0.5, 0 ≦ f ≦ 1, and 0 ≦ g <6; h is the number of oxygen atoms required to satisfy the total valence) In the X-ray diffraction analysis of the catalytically active component by copper Kα rays, to provide a catalyst in which the maximum peak appears at 22.2 ± 0.3 ° (2θ: θ is the diffraction angle), (a) spray drying an aqueous solution or dispersion containing a metal element constituting the catalytically active component (hereinafter referred to as " catalytically active element ") or a compound thereof to provide a dried powder, (b) sintering the dry powder obtained in step (a) to obtain a catalytically active ingredient powder, and (c) coating the carrier with the catalytically active ingredient powder obtained in step (b) using a tumble granulator. The process of claim 1 wherein the reinforcing material is used in step (c) with a powder of the catalytically active component. The process according to claim 1 or 2, wherein the binder in step (c) is used together with a powder of the catalytically active component. The method of claim 3 wherein the binder is a diol or a triol. The method of claim 4 wherein the triol is glycerin. The method of claim 2 wherein the reinforcing material is ceramic fiber. The catalytically active component has a composition represented by the following general formula (1), (Wherein Mo, V, W, Cu, Sb and O represent molybdenum, vanadium, tungsten, copper, antimony and oxygen, respectively X is at least one element selected from the group consisting of alkali metals and thallium, Y is at least one element selected from the group consisting of magnesium, calcium, strontium, barium and zinc, Z is at least one element selected from the group consisting of niobium, cerium, tin, chromium, manganese, iron, cobalt, samarium, germanium, titanium and arsenic, a, b, c, d, e, f, g and h are 0 <a≤10, 0≤b≤10, 0 <c≤6, 0 <d≤10, 0≤e≤ based on 12 molybdenum atoms Atomic ratios of 0.5, 0 ≦ f ≦ 1, and 0 ≦ g <6; h is the number of oxygen atoms required to satisfy the total valence) In the X-ray diffraction analysis of the catalytically active component by copper Kα rays, to provide a catalyst in which the maximum peak appears at 22.2 ± 0.3 ° (2θ: θ is the diffraction angle), (a) spray drying an aqueous solution or dispersion containing the catalytically active element or a compound thereof to provide a dried powder, and (b) sintering the dry powder obtained in step (a) to obtain a catalyst active ingredient powder. The method according to claim 7, wherein the electrical conductivity measured after stirring the mixture of 5 g of dry powder and 75 g of pure water obtained in step (b) for 5 minutes is 100-2,000 μs / cm. The method for producing a catalyst according to claim 8, wherein an aqueous solution or dispersion containing a catalytically active element or a compound thereof is obtained by mixing antimony trioxide and water as an antimony source. 10. The process according to claim 7, wherein the catalyst is used for the production of acrylic acid by catalytic oxidation of acrolein to oxygen molecules in the gas phase. Based on the total volume of pores having a diameter of 0.01 to 200 μm in the catalyst, the volume of the pores having a diameter of 0.01 to 0.1 μm is 20% or less, the volume of the pores having a diameter of 0.1 to 1 μm is 30% or less, 1 In order to provide a catalyst having a volume of pores having ˜10 μm of at least 40% and a volume of pores having 10 to 200 μm of at most 50%, obtained according to the catalyst preparation method according to any one of claims 7 to 9. A method of making a catalyst comprising the step of compressing, extruding or coating the catalyst. 12. The process of claim 11 for use in the production of acrylic acid by catalytic oxidation of acrolein to oxygen molecules in the gas phase.