Method for producing a catalyst for the partial oxidation/ammoxidation of olefins

Abstract

The present invention relates to a method for producing a supported catalyst, a catalyst which is obtainable using the method, and use thereof for the partial oxidation or ammoxidation of olefins, in particular for the oxidation of propene to acrolein, of isobutene to methacrolein, and/or the ammoxidation of propene to acrylonitrile. The method according to the invention includes the following steps: a) providing a solution in which precursor compounds of the catalytically active component are essentially completely dissolved in a suitable solvent; b) bringing the solution obtained in step a) into contact with a (chemically) inert, porous support having a specific surface of 1 to 500 m.sup.2/g; c) heat treatment of the material obtained in step b), in which the precursor compounds of the catalytically active component are converted to their oxides.

Claims

1. A method for producing a catalyst which includes as the catalytically active component a compound having the general formula Mo.sub.xBi.sub.yFe.sub.zA.sub.aB.sub.bC.sub.cD.sub.dO.sub.v, where A stands for Ni and/or Co, B stands for one or more metals selected from Mg, Cr, Mn, Zn, Ce, and Ca and combinations thereof, C stands for W, and D stands for one or more alkali metals, where x stands for a number from 10 to 14, y stands for a number from 0.1 to 5, z stands for a number from 0.5 to 5, a stands for a number from 1 to 10, b stands for a number from 0.1 to 6, c stands for a number from 0 to 2, d stands for a number from 0.02 to 2, and v is determined by the oxidation state of the elements, the method including the following steps: a) providing a solution in which all precursor compounds of the Mo, Bi, Fe, A, B, C and D components of the catalytically active component are essentially completely dissolved in a suitable solvent; b) bringing the solution obtained in step a) into contact with a chemically inert, porous support having a specific surface of 1 to 500 m.sup.2/g; and c) heat treatment of the material obtained in step b), in which the precursor compounds of the catalytically active component are converted to their oxides.

2. The method according to claim 1, wherein step b) includes impregnation of the chemically inert, porous support with the solution obtained in step a).

3. The method according to claim 1, wherein step b) includes coating of the surface of the chemically inert, porous support with the solution obtained in step a).

4. The method according to claim 1, wherein the chemically inert, porous support has a specific surface of 1 to 100 m.sup.2/g.

5. The method according to claim 1, wherein the chemically inert, porous support is formed as a molded body.

6. The method according to claim 1, wherein the chemically inert, porous support is an inorganic support.

7. The method according to claim 1, wherein step c) includes calcination of the material obtained in step b).

8. The method according to claim 1, wherein the heat treatment in step c) includes heating the material obtained in step b) to a temperature of 450 to 650 C. over a period of 1 to 8 hours.

9. The method according to claim 1, wherein the suitable solvent in step a) is an aqueous solvent.

10. A catalyst which includes a compound having the general formula Mo.sub.xBi.sub.yFe.sub.zA.sub.aB.sub.bC.sub.cD.sub.dO.sub.v as the catalytically active component, where A stands for Ni and/or Co, B stands for one or more metals selected from Mg, Cr, Mn, Zn, Ce, and Ca and combinations thereof, C stands for W, and D stands for one or more alkali metals, where x stands for a number from 10 to 14, y stands for a number from 0.1 to 5, z stands for a number from 0.5 to 5, a stands for a number from 1 to 10, b stands for a number from 0.1 to 6, c stands for a number from 0 to 2, d stands for a number from 0.02 to 2, and v is determined by the oxidation state of the other elements, the catalyst being obtainable by a method according to claim 1.

11. The catalyst according to claim 10, where x is 12.

12. A process for the partial oxidation or ammoxidation of olefins, the process comprising oxidizing or ammoxidating an olefin in contact with a catalyst according to claim 10.

13. The process according to claim 12, wherein partial oxidation or ammoxidation of olefins is an oxidation of propene to acrolein, an ammoxidation of propene to acrylonitrile, or an oxidation of isobutene to methacrolein.

14. The method according to claim 1, wherein the suitable solvent in step a) is an aqueous solvent; step b) includes impregnation of or coating the surface of the chemically inert, porous support with the solution obtained in step a), the chemically inert, porous support is an inorganic support having a specific surface of 1 to 100 m.sup.2/g; and step c) includes calcination of the material obtained in step b).

15. The method according to claim 14, wherein the heat treatment in step c) includes heating the material obtained in step b) to a temperature of 450 to 650 C. over a period of 1 to 8 hours.

16. The method according to claim 1, wherein at least 99% by weight of the precursor compounds of the precursor compounds of the catalytically active component are dissolved in the solution of step a).

17. The method according to claim 1, wherein x is 12, y is 0.7 to 1.5, z is 0.7 to 3, a is 2 to 9, c is 0.05 to 1.0, and d is 0.04 to 0.5.

18. The method according to claim 17, wherein the molar ratio of Mo to Bi is 15.5 to 7.7.

19. The method according to claim 18, wherein the molar ratio of Bi to Fe is 0.46 to 1.5.

20. The method according to claim 17, wherein A includes Ni and Co.

Description

EXAMPLES

Example 1

(1) 0.512 g bismuth nitrate, 2.118 g ammonium heptamolybdate, 0.610 g nickel acetate, 0.82 g cobalt acetate, 0.483 g iron(III) nitrate, and 0.43 g magnesium acetate were dissolved in 3 mL of an aqueous glycolic acid solution (70% by weight in water). After dissolution was complete, 0.111 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.062 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 6 g SiC (BET=27 m.sup.2/g, pore volume: 0.9 mL/g). The material obtained was calcined for 4 hours at 500 C., resulting in catalyst 1.

Example 2

(2) 0.512 g bismuth nitrate, 2.118 g ammonium heptamolybdate, 0.610 g nickel acetate, 0.82 g cobalt acetate, 0.322 g iron(III) nitrate, and 0.43 g magnesium acetate were dissolved in 3 mL of an aqueous glycolic acid solution (70% by weight in water). After dissolution was complete, 0.128 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.062 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 6 g SiC (BET=27 m.sup.2/g, pore volume: 0.9 mL/g). The material obtained was calcined for 4 hours at 500 C., resulting in catalyst 2.

Example 3

(3) 0.256 g bismuth nitrate, 1.059 g ammonium heptamolybdate, 0.305 g nickel acetate, 0.41 g cobalt acetate, 0.402 g iron(III) nitrate, and 0.215 g magnesium acetate were dissolved in 3 mL of an aqueous glycolic acid solution (70% by weight in water). After dissolution was complete, 0.085 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.031 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 3 g SiC (BET=27 m.sup.2/g, pore volume: 0.9 mL/g). The material obtained was calcined for 4 hours at 500 C., resulting in catalyst 3.

Example 4

(4) 0.256 g bismuth nitrate, 1.059 g ammonium heptamolybdate, 0.305 g nickel acetate, 0.41 g cobalt acetate, 0.402 g iron(III) nitrate, and 0.108 g magnesium acetate were dissolved in 1.5 mL of an aqueous glycolic acid solution (70% by weight in water). After dissolution was complete, 0.043 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.031 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 3 g SiC (BET=27 m.sup.2/g, pore volume: 0.9 mL/g). The material obtained was calcined for 4 hours at 500 C., resulting in catalyst 4.

Example 5

(5) 0.256 g bismuth nitrate, 1.0593 g ammonium heptamolybdate, 0.305 g nickel acetate, 0.41 g cobalt acetate, 0.402 g iron(III) nitrate, and 0.215 g magnesium acetate were dissolved in 1.5 mL of an aqueous glycolic acid solution (70% by weight in water). After dissolution was complete, 0.043 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.031 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 3 g SiC (BET=27 m.sup.2/g, pore volume: 0.9 mL/g). The material obtained was calcined for 4 hours at 500 C., resulting in catalyst 5.

Example 6

(6) 0.261 g bismuth nitrate, 1.0593 g ammonium heptamolybdate, 0.311 g nickel acetate, 0.418 g cobalt acetate, 0.41 g iron(III) nitrate, and 0.110 g magnesium acetate were dissolved in 1.5 mL of an aqueous glycolic acid solution (70% by weight in water). After dissolution was complete, 0.043 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.032 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 2.2 g SiO.sub.2 (BET=68 m.sup.2/g, pore volume: 1.2 mL/g). The material obtained was calcined for 4 hours at 500 C., resulting in catalyst 6.

Example 7

(7) 0.261 g bismuth nitrate, 1.0593 g ammonium heptamolybdate, 0.311 g nickel acetate, 0.418 g cobalt acetate, 0.41 g iron(III) nitrate, and 0.110 g magnesium acetate were dissolved in 1.5 mL of an aqueous glycolic acid solution (70% by weight in water). After dissolution was complete, 0.043 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.032 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 2.2 g SiO.sub.2 (BET=68 m.sup.2/g, pore volume: 1.2 mL/g). The material obtained was calcined for 3 hours at 550 C., resulting in catalyst 7.

Example 8

(8) 0.279 g bismuth nitrate, 1.0593 g ammonium heptamolybdate, 0.332 g nickel acetate, 0.447 g cobalt acetate, 0.439 g iron(III) nitrate, and 0.030 g magnesium acetate were dissolved in 1.5 mL of an aqueous glycolic acid solution (70% by weight in water). After dissolution was complete, 0.039 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.034 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 2.2 g SiO.sub.2 (BET=68 m.sup.2/g, pore volume: 1.2 mL/g). The material obtained was calcined for 1 hour at 550 C., resulting in catalyst 8.

Example 9

(9) 0.261 g bismuth nitrate, 1.0593 g ammonium heptamolybdate, 0.311 g nickel acetate, 0.418 g cobalt acetate, 0.41 g iron(III) nitrate, and 0.110 g magnesium acetate were dissolved in 1.5 mL of an aqueous glycolic acid solution (70% by weight in water). After dissolution was complete, 0.043 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.032 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 3 g SiC (BET=27 m.sup.2/g, pore volume: 0.9 mL/g). The material obtained was calcined for 1 hour at 590 C., resulting in catalyst 9.

Example 10

(10) 0.279 g bismuth nitrate, 1.0593 g ammonium heptamolybdate, 0.332 g nickel acetate, 0.447 g cobalt, 0.439 g iron(III) nitrate, and 0.030 g magnesium acetate were dissolved in 1.5 mL of an aqueous glycolic acid solution (70% by weight in water). After dissolution was complete, 0.039 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.034 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 3 g SiC (BET=27 m.sup.2/g, pore volume: 0.9 mL/g). The material obtained was calcined for 1 hour at 590 C., resulting in catalyst 10.

Example 11

(11) 0.256 g bismuth nitrate, 1.059 g ammonium heptamolybdate, 0.305 g nickel acetate, 0.41 g cobalt acetate, 0.402 g iron(III) nitrate, and 0.108 g magnesium acetate were dissolved in 1.5 mL of an aqueous lactic acid solution (70% by weight in water). After dissolution was complete, 0.043 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.031 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 3 g SiC (BET=27 m.sup.2/g). The material obtained was calcined for 4 hours at 500 C., resulting in catalyst 11.

COMPARATIVE EXAMPLES

Comparative Example 1

(12) 0.256 g bismuth nitrate, 1.059 g ammonium heptamolybdate, 0.305 g nickel acetate, 0.41 g cobalt acetate, 0.402 g iron(III) nitrate, and 0.108 g magnesium acetate were dissolved in 1.5 mL of an aqueous glycolic acid solution (70% by weight in water). After dissolution was complete, 0.043 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.031 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 3 g SiC (BET=0.001 m.sup.2/g). The material obtained was calcined for 4 hours at 500 C., resulting in catalyst 12.

Comparative Example 2

(13) 0.256 g bismuth nitrate, 1.059 g ammonium heptamolybdate, 0.305 g nickel acetate, 0.41 g cobalt acetate, 0.402 g iron(III) nitrate, and 0.108 g magnesium acetate were dissolved in 1.5 mL of an aqueous glycolic acid solution (70% by weight in water). After dissolution was complete, 0.043 mL of an ammonium metatungstate solution (2.35 M tungsten) and 0.031 mL of a potassium acetate solution (1.13 M) were added. This solution was mixed with 3 g -Al.sub.2O.sub.3 (BET=0.1 m.sup.2/g). The material obtained was calcined for 4 hours at 500 C., resulting in catalyst 13.

Comparative Example 3

(14) A first solution was prepared by dissolving 0.44 g ammonium heptamolybdate and 0.018 g ammonium metatungstate in 0.89 mL water and adding 0.065 g colloidal SiO.sub.2 (BET=129-155 m.sup.2/g; Ludox AS-40). A second solution was prepared by dissolving 0.0149 g bismuth nitrate, 0.312 g nickel nitrate, 0.089 g cobalt nitrate, 0.185 g ferric nitrate, 0.118 g magnesium nitrate, 0.00032 g potassium nitrate, and 0.00061 g cesium nitrate in 0.62 mL water. The two aqueous solutions were combined to form a slurry. To the slurry was added 0.046 g of Coconit 300. The slurry was dried on a hot plate and the solid was further dried at 110 C. The solid was calcined in air at 580 C. for 1 h to produce catalyst 14.

(15) The elemental composition of the obtained material was as follows:

(16) Mo.sub.12Bi.sub.0.15Fe.sub.2.21Ni.sub.5.15Co.sub.1.47Mg.sub.2.21W.sub.0.37K.sub.0.01Cs.sub.0.015Si.sub.5.2

Comparative Example 4

(17) A first solution was prepared by dissolving 0.44 g ammonium heptamolybdate in 0.89 mL water and adding 0.065 g colloidal SiO.sub.2 (BET=129-155 m.sup.2/g; Ludox AS-40). A second solution was prepared by dissolving 0.0286 g bismuth nitrate, 0.24 g nickel nitrate, 0.137 g cobalt nitrate, 0.143 g ferric nitrate, 0.090 g magnesium nitrate, 0.030 g manganese nitrate, 0.030 g cerium nitrate, 0.00023 g potassium nitrate, and 0.00093 g cesium nitrate in 0.83 mL water. The two aqueous solutions were combined to form a slurry. To the slurry was added 0.046 g of Coconit 300. The slurry was dried on a hot plate and the solid was further dried at 110 C. The solid was calcined in air at 580 C. for 1 h to produce catalyst 15.

(18) The elemental composition of the obtained material was as follows:

(19) Mo.sub.12Bi.sub.0.28Fe.sub.1.7Ni.sub.3.97Co.sub.2.27Mg.sub.1.7Mn.sub.0.57Ce.sub.0.34K.sub.0.011Cs.sub.0.023Si.sub.5.2

(20) The elemental composition of the obtained catalysts is summarized in Table 1 below.

Comparative Example 5

(21) A first solution is produced in that 1.02 kg iron nitrate nonahydrate (Honeywell; Lot: B 1960) is added to 0.727 kg deionized water at 60 C. Without further heating the solution 2.37 kg nickel nitrate hexahydrate (ALFA Aesar; Lot: 61101000) and 0.62 kg magnesium nitrate hexahydrate (Honeywell; Lot: 90140) are subsequently added, and the compounds are solved under stirring. Then, 0.039 kg 1 M KOH (Merck; Lot: HC111978) is added. After the addition of KOH a brown precipitate is formed, which is then again quickly solved. Subsequently, 0.3 kg bismuth nitrate pentahydrate (ALFA Aesar; Lot: 42060004) is added.

(22) A second solution is produced by adding 2.62 kg ammoniumheptamolybdat tetrahydrat (HC Starck; Lot: 1163/048) into 8.3 kg deionized water and is solved under stirring.

(23) After that, the first and the second solution are combined and 0.19 kg Syloid C809 (Grace Davison; Lot: 1000214955; colloidal SiO.sub.2) is added. Thereby, a precipitate is formed which forms a suspension with the resulting solution.

(24) The so obtained suspension is spray-calcined in a pulsation reactor of the company IBU-tec (Typ: PR-4). The temperature in the pulsation reactor is 500 C. and the residence time was in the range of 200 ms to 2 s. The obtained material is formed to catalyst 16.

(25) TABLE-US-00001 TABLE 1 Catalyst Mo Bi Fe Ni Co Mg W K Catalyst 1 12 1.05 1.2 2.45 3.3 2.0 0.26 0.07 Catalyst 2 12 1.05 0.8 2.45 3.3 2.0 0.3 0.07 Catalyst 3 12 1.05 2.0 2.45 3.3 2.0 0.4 0.07 Catalyst 4 12 1.05 2.0 2.45 3.3 1.0 0.2 0.07 Catalyst 5 12 1.05 2.0 2.45 3.3 2.0 0.2 0.07 Catalyst 6 12 1.07 2.04 2.5 3.37 1.02 0.2 0.07 Catalyst 7 12 1.07 2.04 2.5 3.37 1.02 0.2 0.07 Catalyst 8 12 1.145 2.18 2.67 3.6 0.28 0.185 0.08 Catalyst 9 12 1.07 2.04 2.5 3.37 1.02 0.2 0.07 Catalyst 10 12 1.145 2.18 2.67 3.6 0.28 0.185 0.08 Catalyst 11 12 1.05 2.0 2.45 3.3 1.0 0.2 0.07 Catalyst 12 12 1.05 2.0 2.45 3.3 1.0 0.2 0.07 Catalyst 13 12 1.05 2.0 2.45 3.3 1.0 0.2 0.07

(26) Test Results:

(27) Catalysts 1 through 16 were tested with regard to their catalytic properties in the partial oxidation of propene. For this purpose, they were added to a multi-channel fixed-bed reactor and exposed to a reaction mixture composed of 8% by volume propene, 14.4% by volume oxygen, 8% by volume water vapor, 10% by volume neon, and the remainder helium at 360 C. for a contact period of 0.5 to 2.5 sec. The results obtained are shown in Table 2 below.

(28) TABLE-US-00002 TABLE 2 Propylene conversion Yield Catalyst rate [%] (acrolein and acrylic acid) [%] Catalyst 1 99.0 95.6 Catalyst 2 99.1 95.8 Catalyst 3 99.1 94.6 Catalyst 4 99.5 96.1 Catalyst 5 99.2 93.9 Catalyst 6 99.0 96.3 Catalyst 7 99.1 96.2 Catalyst 8 99.0 96.2 Catalyst 9 98.4 95.9 Catalyst 10 98.0 95.8 Catalyst 11 98.6 95.9 Catalyst 12* 2.8 2.75 Catalyst 13* 13.8 13.3 Catalyst 14* 91.8 96.0 Catalyst 15* 87.8 94.1 Catalyst 16* 99.5 88.6 *Comparative examples

(29) These results clearly show that the catalysts produced by the method according to the invention are highly effective, selective catalysts for the oxidation of olefins. The catalysts of the comparative examples, in which the same solution was used as for catalyst 4 according to the invention but in which a support not according to the invention, having a low specific surface, was used, are clearly inferior to the catalysts according to the invention, and can by no means be used to achieve the underlying object of the present invention. Catalyst 16 is prepared according to the invention with the only difference that no chelating acid is used in the solution comprising all metal precursor compounds. The use of the pulsating temperature treatment, however, ensures that the disadvantage of the absence of a chelating acid is partly compensated in the catalytic performance. However, when preparing a catalyst according to comparative example 5 but calcining the material at about 550 C. for 1 h in a usual calcining oven instead of the pulsating treatment, the inventors of the present invention observed that the catalytic performance is significantly lower than for catalyst 16.