DE1493283A1 - Process for the manufacture of oxidation catalysts - Google Patents

Description

Dr * Ing, A. vcrn for Terp ^ * Sep. Jf ££ 3283

Pa '; -. Far v ■ -:

21 H «rr. burr. >. '.:.:; ^ _UPg Wilsioner Sir ^ iie 32, Tel. 77 0861

13.99.06

UCB (UNION CHIml ^ UÜ - CHjLiISGIIJ BJDIilJVJNj ti a in t-Gilles-lez-Bruxelles, 4, Chaussee de Charleroi, Br'issel

Belgium

Process for the manufacture of oxidation catalysts

The priority of the corresponding British patent application No. j> 2 208/61 of September 7, 1961 is claimed for this application.

The invention relates to novel Oxyda tion catalysts based on Jisenoxyd- and antimony oxide compounds. The invention also relates to various methods of making these catalysts. Jiese catalysts may be employed in catalytic, tables Oxydationsumsetzungen and in particular for the Jmse "C25unti of a-01efinen iriit j to 6 carbon atoms in the corresponding unsaturated nitriles in the presence of ammonia and an oxygen-containing gas.

The invented catalysts essentially contain as constituents jisen, ^ nticion and oxygen. In these For catalysts, the atomic ratio of iron: antimony is 1: 0.1 up to 1:20, and the best results are achieved with an atomic ratio Ji3eη: Antimony reached from 1: 0.5 to 1: 6.

In principle, catalysts of the invention are hergeoteilt ao that one oäer as Ausgangsraaterialien elemental Jisen Jiaenabkömtnlinge applying and elemental Jisen or ^ ntimonaDkömmlinge, and the same suitable chemical and / or thermal treatments such subjects in that katalyti-specific masses obtained, which practically dae j ^ isene, antimony and the ociusrstoff in the atora ratios given above

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The Elisen harvested from the iron oxides, iilisenhydroxyden and the disene salts of kinetic acids and organic acids, and the antimony compounds from the antimony oxy den and the antimony salts selected from linear acids or organic acids.

To prepare the catalysts of the invention can the various procedures used are of those below for example the most characteristic ones are given5 '

1. Displacement of a mixture of elementary. Antimony and Jisening with ualpitric acid and oxidizing in the gas phase at elevated temperatures Temperature of the resulting oxide mixture with oxygen or a oxygen-containing gas.

2. thermal treatment of x-ntimonoxyd- and jüsenoxyä- and / or Jisenhydroxydgemischen, optionally in the presence of heat decomposable Compounds, such as ..junioniuBiciiloriu, .xmuioniumnitrat, xiarnstoffsa-ize, etc.

P. Addition of one or more initiation oxy de to a solution one or more organic or mineral iron salts, or conversely adding a solution of one or more organic or mineral antimony salts to one or more ^ isene oxides and / or -disenhydroxyden, whereby sicxi in the two cases to the addition a thermal oxidation treatment follows. Lei of this work group you can use the organic or mineral Jisen- or Antimony .aize with a <.; precipitate r üase before performing the thermal oxidation treatment.

4o thermal jxydaüion treatment of a mixture of organic or mineral antitaon salts with organic or mineral - iron salts.

5. Common precipitation in an aqueous ... edium of the ammonium oxides and iron oxides and / or lisenium hydroxides based on them folding by means of a base, as well as thermal oxidation treatment of the mixed precipitate thus obtained in the presence of oxygen or an oxygen-containing gas.

6. Production of Jisen-IlI nitrate in sicu starting from nitric acid and iron in opposition to antimony oxy den, relocate with a base to form an isenoxide and / or isenhydroxydgemiach obtainable with ^ ntimonoxyden, as well as thermal Oxy dtrt ion treatment of the mixture thus obtained in the presence of oxygen or an oxygen-containing gas.

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7. Melting hydrated. Iron-III-nitrate, sodan addition one or more antiinone oxides, as well as treating the Liasse in the heat in the presence of oxygen or an oxygen-containing one Gas.

8. Hydrolysis of the antimony trichlorides and iron-III-chlorides with removal of the malting acid and thermal oxidation treatment, des mixed precipitate thus obtained in the presence of oxygen or an oxygen-containing gas.

Those skilled in the art know that there are numerous other possibilities for preparing the catalysts within the scope of the invention. Before their application is subjected advantageously catalysts of the invention a .aktivierungs- "odär stabilization treatment by using the same to temperatures of 300 ° to 1200 ⁰ C, preferably 500 ° to 900 ° ö about 1 to 200 hours, preferably from 4 to 100 hours, in the presence of be heated by oxygen or an oxygen-containing gas (e.g. air) and optionally in ammonia and / or water vapor and / or inert gases. This treatment gives the catalysts adequate physical properties and an optimal chemical composition. Basically, this activation or stabilization treatment is used to impart a suitable physical structure to the catalysts, in particular a specific surface and a porosity, which require good activity and good selectivity, sufficient service life and corresponding mechanical properties.

In general, the catalysts of the invention are without Carrier applied. However, the catalysts can be used in the same way on! carriers such as pumice stone, colloidal silica, clay, carborundum, arrange etc.

The catalysts can be fluidized in a stationary bed Bed or movable bed in accordance with the conventional ones .Working methods are applied. The catalysts of the invention can be obtained in particular in the form of 'particles that are well suited for iPluidisierung and with respect to abrasion have good resistance,

The catalysts according to the invention are detailed above for the production of unsaturated nitriles starting from used by oc-olefins, uiese catalysts are particularly suitable rürdie Jeberführerun ^ von xropvlen in acrylonitrile.

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The reaction temperature is generally from 200 to 600 ⁰ C, the best ürgebnisse be achieved at a working temperature of 300 ° to 55O ⁰ C.

The exposure time depends of course on the temperature and the desired conversion ratio of the implementation participants. Under the apparent contact time is understood to be the quotient of the apparent Catalyst volume divided by the gas velocity per second under the working conditions. This contact time, which at of practical work is 0.1 to 30 seconds, amounts to preferably to 0.5 to 15 seconds.

Normal pressure is preferably used, but it is possible higher or lower pressures can also be used in the same way.,

The reaction mixture consists of propylene, ammonia, oxygen or an oxygen-containing gas mixture, such as, for example, Air, as well as: also a gaseous diluent such as propane or ethane and optionally water vapor.

The important factors in carrying out the reaction are the composition of the reaction mixture and the proportions of the Implementation participants to each other, whereby these proportions can fluctuate within considerable limits. For example, one turns per part Propylene volume 0.2-5 parts ammonia, 0.1-5 parts oxygen and 0 to 10 parts of water vapor. The diluents used, if any, can be nitrogen, carbon oxides, slightly saturated ones Be hydrocarbons or mixtures thereof, the proportions of which can vary within relatively wide limits.

The gases exiting the reaction vessel are preferred analyzed by means of vapor phase chromatography, either by means of direct removal of the gaseous products or after preliminary absorption in water. Regardless of this, the Leaving gases mostly unchanged starting materials, Acrylonitrile and traces of acetonitrile, hydrogen cyanide, carbon monoxide and carbon dioxide and possibly small amounts of others Byproducts.

The catalysts according to the invention are characterized by a high specificity. Yields of acrylonitrile of $ 80 in relation to the propylene consumed and 55 to 60% in relation to the ammonia consumed are often obtained. The amount of by-produced acetonitrile is generally negligible. At a

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Catalysis in a fluidized bed is not obtained more than 0.5 w / i of this compound in terms of the amount of acrylonitrile formed. If you work in a fixed bed, you usually get one greater tightness of acetonitrile, which, however, does not exceed 570. Farther this amount decreases as a function of the lifetime of the catalyst.

The recovery of the valuable obtained after this reaction Products, in particular of acrylonitrile, are made by known processes, in particular by absorption in water or any other suitable absorption liquid or also by means of condensation below the boiling point of the acrylonitrile.

The invention is described below, for example, by reference explained in detail on a number of exemplary embodiments »

Unless otherwise noted, the gas quantities are in percent by volume expressed. By "conversion" of the propylene is meant the percentage of propylene that is converted during the reaction will. Under "Yield of Acrylonitrile" is the percentage obtained of acrylonitrile in relation to the propylene actually consumed to understand. "Efficiency" of acrylonitrile is the yield of the To understand "Ufliwandluiigsproduktes", i.e. the percentage of the applied Propylene that has been converted to acrylonitrile.

example 1

Manufacture of the Catalysts Catalyst Hr. 1

In 510 ml of nitric acid d = 1.4 there are 4 to 4 g of Fe (NO ₃ ) ₃ . Dissolved 9 H ₂ O and gradually added 121.8 g of powdered antimony to the MIb of the boiling point.

The precipitate obtained is filtered through a Buchner filter i and until the disappearance of iäisenionen washed with water, liach 24 skundigem drying at a temperature of 100 ° 0 12 hours, heated in the presence of .Luft to a temperature of 45O ° G. The product obtained is sorted depending on the desired grain size.
Catalyst Mr. 2

ns are introduced gradually 487 g of powdered .antimon in 2400 ml of nitric acid d = 1.4, which is held in the Wälie the boiling point. The precipitate obtained is filtered through a Buchner filter and washed vigorously with water. The hasse obtained is suspended in a solution which is prepared from 55/9 S Al & en, 250 ia-1 nitric acid d = 1.4 and 500 ml of water

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has been. Ammonia is added to this suspension d = D), 91 to. Complete carcassing is added, stirring vigorously at a temperature of 80 to 100 ⁰ O.

The precipitate is filtered through a Büchner pilter and the mass is taken up in boiling via it. It is again filtered through a Buchner funnel and vigorously washed with water, "JSS is heated oven at 100 ° 0 dried and then 16 Standen long in the presence of air at 45O ⁰ O, is sorted as a function of the desired grain size.
Catalyst STr. 3

The procedure is the same as for the preparation of catalyst no. 2, except that on the one hand 365 »4 g of powdered antimony and 1530 ml of nitric acid d = 1.4 and on the other hand 55» 9 g of isen, 250 ml of nitric acid d = 1.4 and apply 500 ml of water. Catalyst # 4

In a solution of 16 g of ammonium nitrate and 100% ammonia d = 0.91 in 4 liters of water, 90 g of eSO ₄ are stirred while stirring. 7 H _Ä Ü dissolved in 5OO ml of water were added. Then heated to 7O ⁰ C in order to agglomerate the precipitate kan decanted, filtered through a book-Pilter and takes three times in boiling "ater-on. It is then dried at 100 ° for 24 hours and then gradually heated to 250 ° 0 in a stream of air. This temperature is maintained for 2 hours. After cooling, the grains with a diameter of 0.1-0.25 mm are sorted.
Catalyst # 5

There are gradually 365.4 g powdery -untiuon in 150 ml nitric acid d = 1.4 introduced, which is halved near the song point. The precipitate obtained is filtered off through a Buchner filter and washed vigorously with water. Then is heated at 100 ⁰ C and dried in the presence of air for 24 hours at 45O ⁰ O, kan sorted in AbhangigkeiO of the desired grain size.
Catalyst # 6

Js are in 125 µ ml of ammonia d = U, 91 * die 'with 30 µ l of V.' assei have been displaced - gradually, under strong lead a solution introduced the 500 ml of 4 η hydrochloric acid, 684 g of antimony triciiloride and Contains 162.3 g of iron III chloride. The gel obtained is through a Bdehner filter filtered off and taken up three times in boiling water. The plastic mass obtained is in iPäden with a

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Diameter of 3 mm extruded, which are then dried for 24 hours at · 100 ° 0. The Fäden'werden into granules with a length of 3 - 5 mm is cut and then successively for 16 hours at 65O ⁰ O, 16 hours heated at 75O ^Ö Ö and 24 hours at 85O ⁰ O in the presence of air.
Catalyst Mr. 7th

This catalyst is prepared as the catalyst no. 6, but the same to a thermal treatment for 48 hours at 850 ⁰ G in the presence of air is subjected. Catalyst # 8

This catalyst is prepared in the same way as catalyst no. 6, but using a five-fold greater volume of water for dilution of ammonia and does not wash the gel obtained. In the

how

The heat treatment carried out on the air .is the same / for the # 6 catalyst. '
Catalytic converter # 9

jils are 404 g Fe (NOg) ₃ . 9 H ₂ O melted in its own crystal water by heating it slightly. 291 g of antimony trioxide are then gradually added with mixing. It is concentrated to dryness by heating until the development of nitrous vapors has ceased. The powder obtained in this way is compressed and then first crushed into granules with a diameter of 1.5-3 mm. These granules are subjected to a heat treatment for 48 hours at 85 ° O in the presence of air ₀ Catalyst No. 10

In a mixture consisting of 1450 ml of ethylene oxide and 1300 ml of water, which is cooled externally with ice, a solution consisting of 650 ml of 4 η hydrochloric acid, £ 09 »5 g of iron (III) chloride and 456» 2 g are gradually added with stirring Antimony trichloride introduced. The addition is made in such a way that one works slowly enough to avoid evaporation of the ethylene oxide. It is filtered through a Buchner filter and the precipitate is taken up three times in boiling water. Then it is dried for 24 hours at 10ö ° ö. The mass obtained is crushed into grains having a diameter of 1.5 3 mm his and then successively for 16 hours at 650 ° 0, then 16 hours at 75O ⁰ O and finally 5 hours at 850 ⁰ C in the presence of air treated. Catalyst # 11

There are 24 hours in a ball mill 135 »3 g of quartz Crushed with 250 ml v / ater. The slurry thus obtained becomes

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ψ- ■. ■ ..- ■

then mixed with 406 g of catalyst no. 6 previously described in Powder form has been transferred. It is then dried for 24 hours at 100.degree.

Example 2

It will be 100 ml of catalyst No. 1 with a diameter of 0.1-0.25 mm granules in a reaction vessel with fluidized Bed brought in from a Pyrex glass tube with 25 now. Diameter consists. The glass tube is brought into a heated bar. The catalyst is activated by passing a gas mixture through it fluidized, the $ 8.9 propylene (with a degree of purity of more than $ 99) contains $ 10.7 ammonia and $ 80.4 air.

The fluidized bed is at a temperature of 450 ° C held.

The speed of the gas flow is regulated so that P the apparent contact time is 5.8 seconds.

Conversion of propylene 56.87b

Efficiency in terms of acrylonitrile 42.7 "/ °

Efficiency with respect to hydrocyanic acid 4 »4 $

Efficiency in terms of traces of acetonitrile

Example 5 > *

The catalyst no. 2 is used, whereby as in * Embodiment 2 works. The apparent contact time is down to 6 seconds. .

550 ° 0 40O ⁰ O 450 ⁰ G

Conversion of Propylene 34 »3 '/ ° 48» 6 $ 52.2 ^>

Acrylonitrile efficiency $ 27.8 $ 36.9 $ 36,870

»Efficiency with regard to the cyanide . '■.

substance acid 5 »$ 0 $ 4.3 $ 4.5

Efficiency with respect to the acetonitrile 0 / o 0 $ traces

Example 4

100 ml of catalyst no. 3, the particles of which have a diameter of 3.5-3 mm, are placed in a reaction vessel with a stationary catalyst bed and a diameter of 15 mm. leads. The reaction vessel is in a bath of molten metal. The catalyst is kept at 400.degree. C. and the contact time is 8 seconds. The composition of the gas mixture / is as follows: 7.4 '/ propylene, 7.3 $ ammonia, 73.7 $ air and 11.6 $ ^λ water.

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Conversion of the propylene 59,6 ^

Efficiency with regard to the acrylonitrile 45 »2 / ό

Efficiency with regard to the hydrogen cyanide acid 3 »3 $ Efficiency in terms of traces of acetonitrile

Example 5

This example is for comparison purposes.

The same reaction mixture is used as indicated in Example 2, but using catalyst Kr. 5, which contains no antimony. At a working temperature of 400 ^° G and a contact time of 6 values, the following results ^{are obtained} with regard to

Efficiency / of the acrylonitrile 10, 5 / <>

Conversion of Propylene 44 * 5 >>

Efficiency with regard to the xceto »nitrile 4» 2 ^

Efficiency with respect to traces of hydrocyanic acid Efficiency in terms of carbon dioxide 0

Efficiency in terms of carbon dioxide 29 »8 / ^

Yield of acrylonitrile 23.6> o _e

Example 6

This example is also used for comparison purposes.

The procedure is as indicated in Example 2, but using catalyst no. 5, which contains no iron. The implementation temperature amounts to 450 ⁰ C and the apparent contact time to 6 seconds.

Conversion of propylene Π _t Qfi)

Acrylonitrile efficiency '13.37 " v / efficiency with respect to the acetonitrile 1 »9 / <>

Example 7

350 ml of the catalyst No. 6 are placed in a loading vessel with a fixed bed and a diameter of 16 mm. The temperature is kept at 425 ⁰ O by means of a bath of molten nitrate-nitrite. The composition of the gas mixture is the following: 8,7j propylene °, 10.4 / ° ammonia, 70.9 ^£ / ό ^ air and 10.0 water.

The following table shows the results, obtained for different contact lines.

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2 seconds 5.9 seconds 5.8 seconds ,

Conversion of propylene 57 »6 >> 74.1 / °

Efficiency with regard to the acrylonitrile s 47.5? » 5B ₁ 65ε 69.1 /

Efficiency in relation to the acetonitrile 2.1 ^c / o 1.57 ° "

Efficiency with respect to the hydrogen syanide

acid 4, OJo 6.4 / °

Carbon monoxide efficiency 0.8% 2.55 6.0> α

Carbon Dioxide Efficiency 3.2 ^ 6.670 7.3 / "

Yield of acrylonitrile 82.57 »79> ° 79.5 / *

Efficiency based on acrylonitrile

(in relation to HH ₃ J 35.6-fi 44.4> 59, 2.0.

Example 8

üs is specified as in Example 7 with 350 ml of the catalyst " tors ITr. 6 worked. The composition of the gas mixture is that the following: 2.77% propylene, 3.3% ammonia, 66.3% air and 27.7% water.

At a working temperature of 420 ⁰ C and a contact time of 3.6 seconds, the folgendän results are obtained: Conversion of Propylene 100.0> a

Efficiency with respect to the Acrylnibril 74.0 ^

Efficiency based on acetonitrile
Efficiency with respect to hydrocyanic acid. Efficiency with respect to carbon monoxide
Efficiency in terms of carbon dioxide
Yield of acrylonitrile
Yield of acrylonitrile (in relation to IiH ₃ ;

This example shows that one can use the catalysts of the invention achieve particularly high conversions and efficiencies

Example 9

The procedure is as indicated in Example 7, with 350 ml of des Catalyst Ur. 7 can be applied. The composition of the The gas mixture subjected to conversion is as follows: 7.0> o propylene 8.2 / a ammonia, 74.0> Air and 10.8> o water.

With a contact time of 3.9 seconds, the following results are obtained.

traces , 6> 7th 11 9 ^ / ^a 74 57

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6> * 440 ⁰ C -U93283 92.3V » 420 ° σ 9 pounds 64.5 / ο 73, TA % 6Α 58 9τ ° 3fT / ° 4, 0% 18.3 / ° , 1, 69.5? ° 5, 80,

Conversion of propylene degree of effectiveness relative to "of acrylonitrile Degree of effectiveness in relation to acetonitrile Degree of effectiveness in relation to hydrocyanic acid Effectiveness with regard to carbon monoxide Effectiveness with regard to carbon dioxide Yield of acrylonitrile

Efficiency based on acrylonitrile (in relation to NH ₃ ) 48.2 / ό 50.7 / ό

Example 10

Ms is worked as indicated in Example 7, with 35-00 ml of the Katalyeators Ur. 8 can be applied. The composition of the gas mixture is as follows: 7.2% propylene, 9.1% ammonia, 74.6% air and 9.1% water.

With a contact time of 4 seconds, the following results are observed.

40Q ⁰ C 42O ⁰ C

Conversion of propylene 74.4 / ° 88.8>

Efficiency based on the acrylonitrile 58.3-70.2 ^c / °

Efficiency in relation to the acetonitrile 1 »8 '/ ο. traces

Efficiency with respect to the hydrocyanic acid 6.2? 7.1? °

Efficiency in terms of carbon monoxide
Effectiveness with regard to the carbon dioxide
Yield of acrylonitrile 78.3 ^l / o 79.2p

Efficiency in relation to the .acrylonitrile (in relation to

to IiH ₃ T '41.5 A 51.2 £.

Example 11 I.

Ee is worked as i, u example 7, with 325 ml of the catalyst Ur. 9 applies. The subject of the reaction grass mixture has the following composition: 6.8 / £ propylene, 8,45'i jlmmoniak, 74.5 / ° air and 10, 3p v / ater. '

In a Arbeibtemperatur of 420 ⁰ C is obtained at a con tact it ze of 2.4 seconds, the following iirgebnisse: Conversion of Propylene 82>, 8 $>

Efficiency based on acrylonitrile $ 65.9

Efficiency based on acetonitrile 2.3 / ό

Efficiency with respect to hydrocyanic acid 4.0 $>

, / inefficiency in terms of carbon monoxide _ 2.6 ^C A

Efficiency with respect to the Kolklendioxyds 7.0 ^ o

AUebeu ^ e an Acrylnii? Ril 80.6 '/ ό

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Example 12 .

Ea is carried out as in Example 7, using 300 ml of the Catalyst Ur. 10 applies. The one introduced into the sedimentation vessel Gas mixture, has the following composition: 8.3 $ propylene, 10.5 / o ammonia, 64 »2 / air and 17.0 $ water.

With a contact time of 2.6 seconds, the following results are obtained:

425 ° 0 450 ° 0

Conversion of propylene
Efficiency with respect to the acrylonitrile
Efficiency based on acetonitrile
Efficiency with respect to hydrofluoric acid. Efficiency with respect to carbon monoxide
Efficiency with respect to carbon dioxide
i | Yield of acrylonitrile

Example 15

The procedure is as in Example 7, 300 ml of catalyst no. 11 being used. The composition of the gas mixture is the following: 9.0 ^ propylene, 11.1 $ ammonia, 72.1 $ air and $ 7.8 water. i |

At a working temperature of 420 ^° C. and a contact time Jr of 4 seconds, the following results are obtained: |. ^f

Conversion of Propylene · 54.6 $ ...- ".

Efficiency based on acrylonitrile 45.6 / °

Efficiency based on the acetonitrile O *.

Efficiency in relation to the hydrogenated acid 4.0% '*

Efficiency in terms of carbon monoxide 1.5 $ J

W V / efficiency in relation to carbon dioxide 3.5 $ '

Yield of acrylonitrile $ 83.3.

$ 67.5 $ 74.7 53.8 ^ $ 59.0 2.5? O $ 2.1 3, T / o $ 4.9 $ 1.8 $ 2.2 $ 5.7 $ 6.5 $ 79.7 $ 79.0

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Claims (19)

; ;.; U9-3283 P a t en tan s ρ rüch e 1. Catalyst for the production of unsaturated nitriles starting from olefins, ammonia and oxygen or an oxygen containing gas, characterized in that the same iron, Contains antimony and oxygen. 2. Catalyst according to claim 1, characterized in that the same is used for the production of acrylonitrile, starting from propylene. 3. Catalyst according to claim 1, characterized in that the iron: antimony atomic ratio is 1: 0.1 and 1:20, and preferably 1: 0.5 to 1: 6. 4. Catalyst according to Claims 1 to 3, characterized in that the catalyst is arranged on a carrier, 5 «catalyst according to claims 1 to 4» characterized in that that the catalyst prior to its use an activation or stabilization treatment in the presence of oxygen or. an oxygen-containing gas and possibly ammonia and / ods * Water vapor and / or inert gas is subjected by the same to Temperatures from 300 ° to 1200 ° ö, and preferably 500 ° to 900 ° 0, Is heated for 1 to 200 hours, and preferably 4 to 100 hours. 6. Process for producing a catalyst according to the Claims 1 to 5 »characterized in that as starting materials elemental iron or iron derivatives and elemental antimony or antimony derivatives are used and these starting materials appropriate chemical and / or chemical treatments are subjected in such a way that catalysts are obtained which essentially contain iron, antimony and oxygen in atomic proportions according to claim 3 included. ?. Method according to claim 6, characterized in that the Yaise derivatives from iron oxides, iron hydroxides and iron salts mineral or organic acids are selected. 8. The method according to claim 6, characterized in that the Aötimonabkömmlinge from the antimony oxides and the üntinionsalzen mineral or organic acids are selected » 9 «Method according to claim 6, characterized in that a mixture of elemental antimony and iron with nitric acid and in the gas phase at elevated temperature with oxygen or a oxygen-containing gas is treated. - 14 - 909814/1179 CIA.3. 10. The method according to claim 6, characterized in that Antimony oxide and iron oxide and / or iron hydroxide mixtures, if appropriate in the presence of heat-decomposable compounds, such as ammonium-r chloride, ammonium nitrate, urea salts, etc. thermally treated will. 11. The method according to Anspridi 6, characterized in that one or more antimony oxides to a solution of one or more organic or mineral iron salts, or to a solution of one or more organic or mineral antimony salts one or more iron oxides and / or iron hydroxides are added, the addition being followed by a thermal oxidation treatment connects. 12. The method according to claim 6, characterized in that one odeafc several iron oxides and / or iron hydroxides of a solution one or more organic or mineral antimony salts are added and the mixture thus obtained is subjected to a thermal oxidation treatment, 13. The method according to claim 11, characterized in that the organic or mineral iron salts are precipitated with a base before the thermal oxidation treatment is carried out. 14. The method according to claim 12, characterized in that the mineral or organic .antimony salts precipitated with a base are carried out before the thermal oxidation treatment will. 15. The method according to claim 6, characterized in that a mixture of the organic or mineral antimony salts and the organic or mineral iron salts of a thermal one Is subjected to heat treatment. 16. The method according to claim 6, characterized in that one together in the aqueous medium the ^ mtimonoxyde and the iron oxides and / or iron hydroxides starting from .deren corresponding salts precipitate by means of a base, and the resulting mixed Precipitation of a thermal oxidation treatment in the presence of oxygen or an oxygen-containing one. Subject to gas will. 17. The method according to claim 6, characterized in that iron (III) nitrate in situ starting from nitric acid and iron in the presence of .üjrtimonoxyden, and then with a base 809814/1179 added to a mixture of iron oxides and / or iron hydroxides and antimony oxides, and this mixture undergoes a thermal oxidation treatment in the presence of oxygen or an oxygen containing gas is subjected. 18. The method according to claim 6, characterized in that one brings hydrated iron nitrate in its own crystal water to melt, then mixed with antimony oxides and the subjecting the mass obtained in this way to a heat treatment in the presence of oxygen or an oxygen-containing gas, 19. The method according to claim 6, characterized in that a mixture of antimony trichloride and ferric chloride with removal hydrolyzed the hydrochloric acid, and the precipitate thus obtained in the presence of oxygen or an oxygen-containing gas is subjected to a heat treatment. 90-9814 / 1179