DE10321398A1 - Multi-metal oxides, useful as catalysts for gas phase oxidation or ammoxidation, contain molybdenum and vanadium along with other elements and have an i-phase structure - Google Patents

Abstract

Multi-metal oxides containing molybdenum and vanadium also contain lanthanides, transition elements and/or Group 3-6 elements and have an X-ray diffraction pattern with lattice spacings (d(A)) as follows: 3.06 +/- 0.2; 3.17 +/- 0.2; 3.28 +/- 0.2; 3.28 +/- 0.2; 3.99 +/- 0.2; 9.82 +/- 0.4; 11.24 +/- 0.4; and 13.28 +/- 0.5. Multi-metal oxides containing molybdenum and vanadium also contain other metals and have an X-ray diffraction pattern with lattice spacings (d(A)) as follows: 3.06 +/- 0.2; 3.17 +/- 0.2; 3.28 +/- 0.2; 3.28 +/- 0.2; 3.99 +/- 0.2; 9.82 +/- 0.4; 11.24 +/- 0.4; and 13.28 +/- 0.5, the oxides being of formula (I); Aa(Mo5-b-cVbXcOd)1 (I); A = NH4, Na, K, Rb, Cs and/or Tl; X = La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Hf, Nb, Ta, W, Mn, Re, Fe, Co, Ni, Cr, Ru, Rh, Pd, Os, Ir, Pt, Cu, Ag, Au, Zn, Cd, Hg, B, Al, Ga, In, C, Si, Ge, Sn, Pb, P, As, Sb, Bi, S, Se and/or Te; a = 0-1-1; b = 0.25-4.5; and c = 0-4.5, with the proviso that (b + c) at most 4.5. An Independent claim is also included for preparation of the above multi-metal oxide.

Description

The present invention relates to multimetal oxide compositions of the general formula I. A _a [Mo _5-bc V _b X _c O _d ] ₁ (I), With
A = at least one of the elements from the group comprising NH ₄ , Na, K, Rb, Cs and Tl;
X = one or more of the elements from the group comprising La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Hf, Nb, Ta , W, Mn, Re, Fe, Co, Ni, Cr, Ru, Rh, Pd, Os, Ir, Pt, Cu, Ag, Au, Zn, Cd, Hg, B, Al, Ga, In, C, Si , Ge, Sn, Pb, P, As, Sb, Bi, S, Se and Te;
a = 0.1 to 1;
b = 0.25 to 4.5; and
c = 0 to 4.5,
with the proviso that b + c ≤ 4.5,
whose X-ray diffractogram shows the following X-ray diffraction pattern RM, reproduced in the form of network plane distances d [Å] that are independent of the wavelength of the X-radiation used,
there]
3.06 ± 0.2
3.17 ± 0.2
3.28 ± 0.2
3.99 ± 0.2
9.82 ± 0.4
11.24 ± 0.4
13.28 ± 0.5,
contains.

Mo and V as well as at least two elements selected from the group comprising lanthanides, transition elements of the periodic table and elements of the third to sixth main group of the periodic table containing multimetal oxide masses whose X-ray diffractogram contains the X-ray diffraction pattern RM are known (cf. e.g. DE-A 10248584 . DE-A 10254279 . DE-A 10051419 . DE-A 10046672 . DE-A 10261186 . EP-A 1090684 . DE-A 19835247 . DE-A 10254278 . EP-A 895809 . DE-A 10122027 . JP-A 7-232071 and JP-A 11-169716 ).

The X-ray diffraction pattern RM forms the fingerprint of a special crystal structure, one special crystal phase, which in the above-mentioned state the technology is referred to as "i-phase".

From the above writings further known that the i-phase is only a crystalline phase, in which such multimetal oxide masses can occur.

A second specific crystal structure in which such multimetal oxide masses can occur is referred to in the prior art as the k phase. Your X-ray diffractogram is characterized in accordance with the abovementioned writings, inter alia, by the fact that it has the following diffraction reflections representing the network level d [Å]:
4.02 ± 0.2,
3.16 ± 0.2,
2.48 ± 0.2,
2.01 ± 0.2, and
1.82 ± 0.1.

i-phase and k-phase are similar to each other, However, the main difference is that the X-ray diffractogram the k phase normally has no diffraction reflections for d ≥ 4.2 Å. Usually contains the k phase also no diffraction reflections in the range 3.8 Å ≥ d ≥ 3.35 Å. Further contains the k phase usually no diffraction reflections in the range 2.95 Å ≥ d ≥ 2.68 Å.

From the aforementioned prior art it is also known that such multimetal oxide compositions are active compositions for catalysts for heterogeneously catalyzed partial gas phase oxidation and heterogeneously catalyzed partial gas phase ammoxidation (differs from the pure partial gas phase oxidation essentially through the additional Presence of ammonia) of lower (especially 2, 3 and / or 4 Alkanes, alkenes, alcohols and aldehydes containing carbon atoms are suitable. Partial oxidation products include α, β-monoethylenically unsaturated Aldehydes (e.g. acrolein and methacrolein) and α, β-monoethylenically unsaturated carboxylic acids (e.g. acrylic acid and methacrylic acid) and their nitriles (e.g. acrylonitrile and methacrylonitrile).

Furthermore, it is known from the abovementioned prior art that the catalytic activity (activity, selectivity of target product formation) of the multimetal oxide compositions having the i-phase structure compared to those in other (e.g. k-phase) structure is usually superior.

From the aforementioned prior art but is also known to be very difficult to mo and v as well selected at least two elements from the group comprising lanthanides, transition elements of the periodic table and elements of the third to sixth main group of the periodic table to produce containing multimetal oxides in i-phase structure.

According to the known methods, mixed-crystal systems are generally obtained which only have a certain i-phase fraction (for example in addition to the k-phase) and from which the i-phase fraction is isolated under the aspect of optimum catalyst performance in that the other phases (for example the k phase) are washed out with suitable liquids (for example WO 0206199, JP-A 7-232071 and DE-A 10254279 ).

Furthermore, from the cited state known in the art that significant i-phase shares according to the known manufacturing methods So far, can only be obtained if the multimetal oxide in addition Mo and V still Nb and at least one of the two elements Te and Sb contains.

The object of the present invention therefore consisted of Mo and V and optionally one or more Items selected from the group comprising lanthanides, transition elements of the periodic table and elements of the third to sixth main group of the periodic table to provide containing multimetal oxides, which are based on comparative simple way with elevated i-phase share or available as pure i-phase are.

To solve this problem it was possible to start from Ultramicroscopy 52 (1993) pp. 429-435, from which multimetal oxides Cs _x (Nb, W) ₅ O _{14 are} known, which contain the proportions in which Nb, W and O are spatially Phase structure are arranged and in which the Cs occupies tunnel-shaped cavities in the crystal structure of the i-phase.

From Journal of Solid State of Chemistry 163, 210 to 217 (2002) are vanadium-molybdenum bronzes containing K, Rb or Cs known that have no i-phase shares.

From Journal of Solid State Chemistry 162, 341-346 (2002) K or Cs containing tungsten-molybdenum bronzes are also known have no i-phase components.

From the US 6428765 B1 Multimetal oxides are known which may contain the element combination Mo and V as well as alkali and / or NH ₄ , but the element combination Mo / V is not present in any of the exemplary embodiments.

In contrast to this, the exemplary embodiments of FIG US 6171571 B1 although the element combination Mo / V, but only in combination with the comparatively small-atom alkali element Li.

The presence of i-phase components is in both cases not visible.

Also in Chemica Scripta 1988, 28, pp. 77 to 80 disclosed potassium-containing tungsten-niobium bronzes show no i-phase shares.

In view of this prior art, it was surprising that the solution to the problem according to the invention was found to be that Mo and V and, if appropriate, one or more elements from the group comprising lanthanides, transition elements of the periodic table and elements of the third to sixth main group of the periodic table containing multimetal oxides with increased probability with significant i-phase fractions (or exclusively with the crystal structure of the i-phase), if they are produced in the presence of NH ₄ or alkali with a radius larger than Li.

This is surprisingly true The above also if neither Nb nor Te, or Sb as accompanying elements are contained in the multimetal oxide.

The generic formulas of the fonts do indeed EP-A 1 256 381 . EP-A 1 254 708 . EP-A 1 254 709 . EP-A 1 254 707 and EP-A 1 254 706 the presence of alkali does not preclude alkali from being used in any single embodiment of these publications. For the rest, in these writings Li is seen as an equal alkali companion.

As a solution to the problem underlying this document, multimetal oxides of the general formula I are A _a [Mo _5-bc V _b X _c O _d ] ₁ (I), With
A = at least one of the elements from the group comprising NH ₄ , Na, K, Rb, Cs and Tl;
X = one or more of the elements from the group comprising La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Hf, Nb, Ta , W, Mn, Re, Fe, Co, Ni, Cr, Ru, Rh, Pd, Os, Ir, Pt, Cu, Ag, Au, Zn, Cd, Hg, B, Al, Ga, In, C, Si , Ge, Sn, Pb, P, As, Sb, Bi, S, Se and Te;
a = 0.1 to 1, preferably 0.2 to 0.8, particularly preferably 0.3 to 0.7 and very particularly preferably 0.4 to 0.6;
b = 0.25 to 4.5; and
c = 0 to 4.5,
with the proviso that b + c ≤ 4.5,
whose X-ray diffractogram shows the following X-ray diffraction pattern RM, reproduced in the form of network plane distances d [Å] that are independent of the wavelength of the X-radiation used,
there]
3.06 ± 0.2 (preferably ± 0.1)
3.17 ± 0.2 (preferably ± 0.1)
3.28 ± 0.2 (preferably ± 0.1)
3.99 ± 0.2 (preferably ± 0.1)
9.82 ± 0.4 (preferably ± 0.2)
11.24 ± 0.4 (preferably ± 0.2)
13.28 + 0.5 (preferably ± 0.3),
contains, provided.

about the X-ray diffraction pattern shows the above-mentioned diffraction reflex layers RM of the multimetal oxide compositions according to the invention in many cases (dependent on of the contained elements and the crystallite geometry (e.g. Needle shape or platelet shape)) additionally characteristic diffraction reflex intensities.

Relative to the intensity of the diffraction reflex representing the network plane distance d [Å] = 3.99 ± 0.2, these (relative) diffraction reflex intensities I (%) are as follows: there] I (%) 3.06 ± 0.2 5 to 65 3.17 ± 0.2 5 to 65 3.28 ± 0.2 15 to 130, often 15 to 95 3.99 ± 0.2 100 9.82 ± 0.4 1 to 50, often 1 to 30 11.24 ± 0.4 1 to 45, often 1 to 30 13.28 ± 0.5 1 to 35, often 1 to 15.

A is preferred according to the invention at least one of the elements from the group comprising K, Rb and Cs. Especially A is preferred Rb and / or Cs and is very particularly preferred A Cs.

X is preferably one or more Elements from the group comprising Ti, Zr, Ta, Cr, W, Mn, Re, Fe, Co, Ni, Pd, Pt, Cu, Ag, Au, Zn, Al, Ga, In, Ge, Sn, Pb, P, Sb, Bi, Se and Te.

X is particularly preferably one or several elements from the group comprising Ti, Cr, W, Mn, Re, Fe, Co, Ni, Pd, Pt, Cu, Ag, Ga, Sn, Sb and Te.

The stoichiometric coefficient c is preferably> 0, particularly preferably 0.05 to 4.5 and very particularly preferably 0.05 to 4.0.

The stoichiometric coefficient b is advantageously 0.5 to 2.5.

In addition, it is for the multimetal oxides according to the invention generally advantageous if a = 0.2 to 0.8, preferably 0.3 to 0.7 and particularly preferably 0.4 to 0.6. The experimental determination of the Oxygen content can e.g. using an oxygen determinator LECO Corporation (USA) (e.g. using a TC-436 from LECO).

Furthermore, it is advantageous for the multimetal oxides according to the invention if the V contained therein is more than 25 mol%, particularly preferably more than 50 mol% and very particularly preferably more than 75 mol% or 100 mol% in the oxidation state + 4 is present. The experimental verification of the oxidation state of the V can be done titrimetrically, as in the EP-A 774297 is described.

In addition to the already mentioned, particularly characteristic, diffraction reflections, the following diffraction reflections, which are also represented in the form of network plane spacings d [Å] independent of the wavelength of the x-ray radiation used, can often be seen in the x-ray diffraction pattern representing the i-phase for the multimetal oxides according to the invention:
there]
8.19 ± 0.3 (preferably ± 0.15)
3.51 ± 0.2 (preferably ± 0.1)
3.42 ± 0.2 (preferably ± 0.1)
3.34 ± 0.2 (preferably ± 0.1)
2.94 ± 0.2 (preferably ± 0.1)
2.86 ± 0.2 (preferably ± 0.1)

Relative to the intensity of the diffraction reflex representing the network plane spacing d [Å] = 3.99 ± 0.2, the (relative) intensities I (%) of the above diffraction reflections are often as follows: there] I (%) 8.19 ± 0.3 (or ± 0.15) 0 to 25 3.51 ± 0.2 (or ± 0.1) 2 to 50 3.42 ± 0.2 (or ± 0.1) 5 to 75 3.34 ± 0.2 (or ± 0.1) 5 to 80 2.94 ± 0.2 (or ± 0.1) 5 to 55 2.86 ± 0.2 (or ± 0.1) 5 to 60.

In many cases, the following diffraction reflections complement the X-ray diffraction pattern that represents the i-phase:
there]
2.54 ± 0.2 (preferably ± 0.1)
2.01 ± 0.2 (preferably ± 0.1)

The (relative) diffraction reflex intensities obtained in the same way as above are often as follows for these diffraction reflections: there] I (%) 2.54 ± 0.2 (or ± 0.1) 0.5 to 40 2.01 ± 0.2 (or ± 0.1) 5 to 60.

Multimetal oxides according to the invention are preferred according to the invention in their X-ray diffractogram which is the network plane distance d [Å] = 3.99 ± 0.2 (or ± 0.1) or the network plane distance d [Å] = 3.28 ± 0.2 (or ± 0.1) representing Diffraction reflex is the most intense (most intense) diffraction reflex.

Furthermore, those are multimetal oxides preferred, where the 2⊝ half width of the diffraction reflex d [Å] = 3.99 ± 0.2 (or ± 0.1) ≤ 1 °, preferably ≤ 0.5 °. The 2⊝ half-width the other listed Diffraction reflexes is normally ≤ 3 °, preferably ≤ 1.5 °, especially preferably ≤ 1 °.

All information in this document relating to an X-ray diffractogram is based on an X-ray diffractogram generated using Cu-Kα radiation (λ = 1.54178 Å) (Siemens diffractometer Theta-Theta D-5000, tube voltage: 40 kV, tube current : 40 mA, aperture diaphragm V20 (variable), anti-scatter diaphragm V20 (variable), secondary monochromator diaphragm (0.1 mm), detector diaphragm (0.6 mm), measuring interval (20): 0.02 °, measuring time per step: 2.4 s , Detector: Scintillation counter tube; the definition of the intensity of a diffraction reflex in the X-ray diffractogram in this document refers to that in the DE-A 19835247 , the DE-A 10122027 , as well as in the DE-A 10051419 and DE-A 10046672 laid down definition; the same applies to the definition of the 2⊝ half-width).

The wavelength λ of the X-ray radiation used for diffraction and the diffraction angle ⊝ (the apex of a reflection in the 2⊝ plot is used as the diffraction reflex layer in this document) are linked as follows via the Bragg relationship: 2 sin ⊝ = λ / d , where d is the network plane spacing of the atomic spatial arrangement belonging to the respective diffraction reflex.

The production of the multimetal oxide compositions according to the invention usually succeeds in that one can find suitable sources of elementary Constituents of the multimetal oxide mass as intimate as possible, preferably finely divided, dry mixture (of the desired constituent stoichiometry) generated and this at temperatures of 350 to 1000 ° C or 400 up to 700 ° C or 400 to 650 ° C or 400 to 600 ° C thermally treated.

The thermal treatment can in principle both under oxidizing, reducing, and under inert the atmosphere respectively. The oxidizing atmosphere is e.g. Air, with molecular Oxygen-enriched air or air de-oxygenated into consideration. However, the thermal treatment is preferred in an inert atmosphere, i.e. e.g. carried out under molecular nitrogen and / or noble gas. Usually thermal treatment takes place at normal pressure (1 atm). Of course you can thermal treatment even under vacuum or under positive pressure respectively.

The thermal treatment takes place under gaseous The atmosphere, it can both stand and flow. It preferably flows. Overall, the thermal treatment can last up to 24 hours or more Claim.

The thermal is preferred Treatment first in an oxidizing (oxygen-containing) atmosphere (e.g. in air) at a temperature of 150 to 400 ° C or 250 to 350 ° C (= pre-decomposition step). Thereafter, the thermal treatment is expediently under Inert gas at temperatures from 350 to 1000 ° C or 400 to 700 ° C or 400 up to 650 ° C or 400 to 600 ° C continued.

The intimate mixing of the starting compounds can be done in dry or wet form.

If it is done in a dry form, be the starting compounds expediently used as a fine powder and after mixing and optionally Compacting subjected to calcination (thermal treatment).

However, the intimate mixing is preferably carried out in wet form. Usually, the starting compounds are in the form of an aqueous solution (optionally with the use of complexing agents; cf. for example DE-A 10145958 ) and / or suspension mixed together. The aqueous mass is then dried and, after drying, calcined. The aqueous mass is expediently an aqueous solution or an aqueous suspension. The drying process preferably takes place immediately after the preparation of the aqueous mixture (in particular in the case of an aqueous solution; cf. for example JP-A 7-315842 ) and by spray drying (the outlet temperatures are usually 100 to 150 ° C; the spray drying can be carried out in cocurrent or in countercurrent), which requires a particularly intimate dry mixture, especially if the aqueous mass to be sprayed is a aqueous solution or suspension. However, it can also be dried by evaporation in vacuo, by freeze spraying, by freeze-drying or by conventional evaporation.

It is also favorable to produce the multimetal oxides according to the invention by a hydrothermal route, such as, for example, the DE-A 10029338 and the JP-A 2000-143244 describe.

As sources for the elementary constituents come as part of the implementation the above-described production methods of multimetal oxide compositions according to the invention all those considered when heating (if necessary, on Air) are able to form oxides and / or hydroxides. Of course, as such starting compounds also include oxides and / or hydroxides of the elementary constituents used or used exclusively become. That is, in particular, all come in the writings of the honored Starting compounds mentioned in the prior art.

Suitable sources for the element according to the invention Mo are e.g. molybdenum oxides like molybdenum trioxide, Molybdates such as ammonium heptamolybdate tetrahydrate and molybdenum halides like molybdenum chloride.

Suitable starting compounds for element V to be used according to the invention are, for example, vanadium oxysulfate hydrate, vanadylacetylacetonate, vanadates such as ammonium metavanadate, vanadium oxides such as vanadium pentoxide (V ₂ O ₅ ), vanadium halides such as vanadium tetrachloride (VCl ₄ ) and vanadium oxyhalides such as VOCl ₃ . It is also possible to use those starting vanadium compounds which contain the vanadium in oxidation state +4.

It is favorable according to the invention as sources for the element V Mixtures of compounds containing element V in the oxidation state +5 contain, and elementary vanadium. This mixture can then, at the latest in the calcination, the average oxidation state preferred according to the invention Form +4 of V.

If only sources containing the V are used as sources of V, it is advantageous according to the invention to use starting compounds which contain reducing agents other than elemental vanadium (for example NH ₄ ⁺ or its decomposition product NH ₃ ) and those of ^Able to reduce V ⁵⁺ to V ^{4 +} . Such a reducing agent can also be oxalic acid, oxalate (for example as a niobium oxalate), hydrazine dihydrochloride, hydrazine sulfate, hydrazine (monohydrate), hydroxylamine, hydroxylamine hydrochloride or their salts. The intimate dry mixture is preferably prepared under an inert gas atmosphere (for example N ₂ ) in order to ensure better control over the oxidation levels.

According to the invention, tellurium oxides such as tellurium dioxide, metallic tellurium, tellurium halides such as TeCl ₂ , but also telluric acids such as orthotelluric acid H ₆ TeO ₆ are suitable as sources for the element tellurium. Of course, elemental tellurium or other constituents in elemental form (eg antimony, iron, samarium, zinc, aluminum, arsenic) can also be used as reducing agents (eg for V ⁵⁺ ).

Further advantageous antimony starting compounds are antimony halides such as SbCl ₃ , antimony oxides such as antimony trioxide (Sb ₂ O ₃ ), antimonic acids such as HSb (OH) ₆ , but also antimony oxide salts such as antimony oxide sulfate (SbO) ₂ SO ₄ .

Suitable niobium sources according to the invention are e.g. B. niobium oxides such as niobium pentoxide (Nb ₂ O ₅ ), niobium oxide halides such as NbOCl ₃ , niobium halides such as NbCl ₅ , but also complex compounds of niobium and organic carboxylic acids and / or dicarboxylic acids such as. B. oxalates and alcoholates. Of course, those in the EP-A 895 809 used solutions containing Nb.

Regarding all other possible Elements (in particular Fe, Pb, Ni, Cu, Co, Bi and Pd as well as the Alkali elements) come above all as suitable starting compounds their halides, nitrates, formates, oxalates, acetates, hydrogen carbonates, Carbonates and / or hydroxides into consideration. Suitable starting compounds are often their oxo compounds such. B. tungstates or the acids derived from these. Frequently ammonium salts are also used as starting compounds.

Also suitable as starting compounds are polyanions of the Anderson type, as z. B. in Polyhedron Vol. 6, No. 2, pp. 213-218, 1987. Another suitable literature source for Anderson type polyanions, Kinetics and Catalysis, Vol. 40, No. 3, 1999, pp 401 to 404.

Other suitable as starting compounds Polyanions are e.g. B. those of the Dawson or Keggin type. Preferably are used such starting compounds that either at elevated temperatures in the presence or in the absence of oxygen, if necessary under Gaseous release Compounds to convert into their oxides.

The teachings of. Are of course also applicable to the multimetal oxide compositions according to the invention JP-A 8-57319 as well as the EP-A 1254707 applicable, according to which the catalytic performance (activity and selectivity of the target product formation) of Mo and V-containing multimetal oxide materials can be improved by treatment with suitable liquids, for example acids.

As such liquids come e.g. organic acids and inorganic acids and their watery solutions (e.g. oxafic acid, formic acid, Acetic acid, Citric acid, Tartaric acid, Nitric acid, Sulfuric acid, perchloric acid, Hydrochloric acid, telluric, boric acid and their mixtures and aqueous Solutions), but also alcohols, alcoholic solutions of the aforementioned acids and aqueous Hydrogen peroxide solutions.

Remarkably, such increases Washing in the event of a phase heterogeneity of the multimetal oxides according to the invention their i-phase portion (other phases, e.g. the k-phase, are preferably extracted).

Such washing also diminishes usually the content of the multimetal oxide compositions according to the invention the elements A relative to their Mo content without the i-phase formed in the multimetal oxide masses is impaired.

A subsequent decrease in salary the multimetal oxide compositions according to the invention of the elements A relative to the Mo content is also possible in that one with liquids extracted, which are preferably able to accommodate elements A. Such liquids are e.g. Liquids, which contain complexing agents (e.g. crown ethers) for element A. Of course, as such liquids but also solutions inorganic salts or melts of these salts or ionic liquids be used.

• a) kein Nb, oder
• b) kein Te, oder
• c) kein Sb, oder
• d) kein Nb und kein Te, oder
• e) kein Nb und kein Sb

enthalten. Normalerweise erfolgt die Behandlung bei Normaldruck und nimmt wenige Stunden bis wenige Tage in Anspruch. Bei Behandlung mit Lösungen wird vorzugsweise unter Rückfluß gearbeitet. Abschließend wird normalerweise mit Wasser gewaschen.The aforementioned treatment of multimetal oxides according to the invention with suitable liquids or molten salts can be carried out at temperatures of 20 to 600 ° C or 400 ° C, or 40 to 380 ° C or 45 to 100 ° C and is of interest, inter alia, for multimetal oxides which

• a) no Nb, or
• b) no Te, or
• c) no Sb, or
• d) no Nb and no Te, or
• e) no Nb and no Sb

contain. The treatment is usually carried out at normal pressure and takes a few hours to a few days. When treating with solutions, work is preferably carried out under reflux. Finally, it is usually washed with water.

The proportion is advantageous according to the invention of elements A from the multimetal oxides according to the invention subsequently so far removed that relationship [5-b-c] / a by at least 5%, preferably by at least 25%, especially preferably by at least 50% and very particularly preferably by at least 75% increases (based on the initial value; often the ratio [5-b-c] / a increase by no more than 200% or by no more than 100%). The elements A can later from the multimetal oxide compositions according to the invention as described also completely removed without significant structural changes accompanied. For reasons the economy becomes common not a complete one Removal of elements A.

The multimetal oxides according to the invention can be used as such (masses 1), or after partial or complete removal of the elements A contained in them (masses 2) which after drinking the Mass 1 or mass 2 with solutions of promoter element compounds (e.g. aqueous), drying and repeated thermal Treat (preferably in an inert gas stream and preferably without pre-decomposition in air) as active mass for Catalysts are used. Soaking is cheap solutions of salts of the elements Pb, Ni, Co, Bi, Pd, Ag, Pt, Cu, Au, Ga, Zn, Sn, In, Re, Ir, Sm, Sc, Y, Pr, Nd and Tb. The latter especially then when the one to be soaked Multimetal oxide does not yet contain these elements. Preferred for such a watering aqueous Nitrate and / or halide solutions of these elements or watery solutions used in which these elements with organic compounds (e.g. acetates or acetylacetonates) are complexed.

Use as an active material for catalysts can be done in powder form or molded. there the catalyst bed can be a fixed bed, a moving bed or a fluidized bed his.

The shaping into shaped bodies can take place, for example, by application to a carrier body, as described in the DE-A 10118814 or the PCT / EP / 02/04073 or the DE-A 10051419 is described.

The carrier bodies to be used for this are preferably chemically inert. That is, they intervene in the process of partial catalytic gas phase oxidation or amoxidation, which is catalyzed by the active materials, essentially not on.

According to the invention, in particular, come as the material for the carrier body Aluminum oxide, silicon dioxide, silicates such as clay, kaolin, steatite (preferably with a low water-soluble alkali content), pumice, Aluminum silicate and magnesium silicate, silicon carbide, zirconium dioxide and thorium dioxide.

The surface of the carrier body can be both smooth and be rough too. The surface of the carrier body is advantageously rough because of an increased surface roughness usually an increased Adhesion of the applied active material shell conditionally.

Frequently lies the surface roughness Rz of the carrier body in Range from 5 to 200 µm, often in the range from 20 to 100 µm (determined according to DIN 4768 Sheet 1 with a "Hommel Tester for DIN-ISO surface measurements "from Hommelwerke, DE).

Furthermore, the carrier material porous or nonporous his. Conveniently, the carrier material is non-porous (total volume of the pores based on the volume of the carrier body ≤ 1% by volume).

The thickness of the coated catalysts according to the invention active oxide mass shell is usually 10 to 1000 microns. she can but also 50 to 700 μm, 100 to 600 μm or 150 to 400 μm be. Possible Shell thicknesses are also 10 to 500 μm, 100 to 500 μm or 150 up to 300 μm.

In principle, come for the method according to the invention any geometries of the carrier body in Consideration. Your longest dimension is usually 1 to 10 mm. Preferably, however, balls or cylinders, especially hollow cylinder, used as a carrier body. Favorable diameter for carrier balls 1.5 to 4 mm. If cylinders are used as carrier bodies, their Length preferred 2 to 10 mm and their outer diameter preferably 4 to 10 mm. In the case of rings, the wall thickness is also usually more at 1 to 4 mm. Suitable according to the invention annular Carrier bodies can also a length from 3 to 6 mm, an outer diameter of 4 to 8 mm and a wall thickness of 1 to 2 mm. Is possible but also a carrier ring geometry of 7 mm × 3 mm × 4 mm or 5 mm × 3 mm × 2 mm (Outer diameter × length × inner diameter).

The production of such coated catalysts can be done in the simplest way so that the active mass is modeled, it is converted into a finely divided form and finally with the help of a liquid Binder on the surface of the carrier body. This is the surface of the carrier body in easiest way with the liquid Binder moistened and brought into contact with fine particles Active compound a layer of the active compound attached to the moistened surface. Finally the coated carrier body is dried. Of course, the process can be used to achieve an increased layer thickness repeat periodically. In this case the coated body becomes new "carrier body" etc.

The fineness of the catalytically active oxide mass to be applied to the surface of the carrier body is of course adapted to the desired shell thickness. For the shell thickness range from 100 to 500 µm, z. B. those active mass powders, of which at least 50% of the total number of powder particles pass through a sieve with a mesh size of 1 to 20 µm and whose numerical proportion of particles with a longest dimension above 50 is less than 10%. As a rule, the distribution of the longest dimensions of the powder particles corresponds to a Gaussian distribution due to the manufacturing process. The grain size distribution is often as follows:

Here are:
D = diameter of the grain,
x = the percentage of grains whose diameter is ≥ D; and
y = the percentage of grains whose diameter is <D.

For carrying out the described coating process on an industrial scale, emp is missing z. B. the application of the in DE-A 2909671 , as well as that in the DE-A 10051419 disclosed process principle. That is, the carrier bodies to be coated are rotated in a preferably inclined (the angle of inclination is usually ≥ 0 ° and ≥ 90 °, usually ≥ 30 ° and ≤ 90 °; the angle of inclination is the angle of the central axis of the rotary container against the horizontal) B. turntable or coating drum). The rotating rotary container leads the z. B. spherical or cylindrical carrier body under two consecutively arranged metering devices at a certain distance. The first of the two metering devices suitably corresponds to a nozzle (for example an atomizer nozzle operated with compressed air) through which the carrier bodies rolling in the rotating rotary plate are sprayed with the liquid binder and moistened in a controlled manner. The second metering device is located outside the atomizing cone of the sprayed-in liquid binder and serves to supply the finely divided oxidic active material (for example via a shaking channel or a powder screw). The controlled moistened carrier balls take up the supplied active mass powder, which is caused by the rolling movement on the outer surface of the z. B. compacted cylindrical or spherical support body into a coherent shell.

If necessary, it runs through the base coat Carrier body in Course of the subsequent rotation the spray nozzles, in turn while being humidified in order to keep moving take up another layer of finely divided oxidic active material to be able to etc. (intermediate drying is usually not necessary). Finely divided oxidic active material and liquid binder are used usually fed continuously and simultaneously.

The removal of the liquid binder can after the coating z. B. by the action of hot gases, such as N2 or air. Remarkably, this does the described Coating process both a fully satisfactory liability of the successive layers on each other, as well as the base layer on the surface of the carrier body.

It is essential for the coating method described above that the moistening of the surface of the carrier body to be coated is carried out in a controlled manner. In short, this means that the carrier surface is expediently moistened in such a way that, although it has adsorbed liquid binder, no liquid phase as such appears visually on the carrier surface. If the surface of the carrier body is too moist, the finely divided catalytically active oxide mass agglomerates into separate agglomerates instead of being drawn onto the surface. Detailed information can be found in the DE-A 2909671 and in the DE-A 10051419 ,

The aforementioned final removal of the liquid used Binder can in a controlled manner, for. B. by evaporation and / or sublimation. In the simplest case, this can be done hotter by exposure Gases of the appropriate temperature (often 50 to 300, often 150 ° C) occur. By Exposure hotter However, gases can only be pre-dried. The final drying can then, for example, in a drying oven of any kind (e.g. B. belt dryer) or in the reactor. The acting temperature should not be above that for the production of the oxidic active material maximum calcination temperature applied. Of course you can drying also exclusively in a drying oven become.

As binders for the coating process, regardless of the type and geometry of the carrier body used water, monohydric alcohols such as ethanol, methanol, propanol and butanol, polyhydric alcohols such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol or glycerin, mono- or polyvalent organic carboxylic acids such as propionic acid, oxalic acid, malonic, glutaric or maleic acid, Amino alcohols such as ethanolamine or diethanolamine as well as one or polyvalent organic amides such as formamide. Cheap binders are also Solutions, consisting of 20 to 90 wt .-% water and 10 to 80 wt .-% one dissolved in water organic compound, its boiling point or sublimation temperature at normal pressure (1 atm)> 100 ° C, preferably> 150 ° C. With The organic compound from the above listing is advantageous potential organic binder selected. Preferably is the organic portion of the aforementioned aqueous binder solutions 10 up to 50 and particularly preferably 20 to 30% by weight. As organic Components also come in monosaccharides and oligosaccharides such as glucose, fructose, sucrose or lactose as well as polyethylene oxides and polyacrylates.

It is important that the manufacture the shell catalysts not only by applying the finished, finely ground active oxide masses take place on the moistened surface of the carrier body can.

Rather, instead of being active Oxide mass also a finely divided precursor mass of the same on the moistened Carrier surface (under Application of the same coating method and binder) applied and the calcination can be carried out after drying the coated carrier body (it can also carrier body with impregnated with a precursor solution, below dried and then be calcined). Finally can, if necessary, the phases other than the i-phase and / or the elements A are washed out.

As such a finely divided precursor mass z. B. the mass that can be obtained by first generating an intimate, preferably finely divided, dry mixture from the sources of the elemental constituents of the desired active oxide mass (for example by spray drying an aqueous suspension or solution of the sources) and this finely divided dry mixture at a temperature of 150 to 350 ° C, preferably 250 to 350 ° C under an oxidizing (oxygen-containing) atmosphere (e.g. in air) thermally treated (a few hours) and finally subjected to grinding if necessary.

After coating the carrier body with the precursor mass will then come, preferably under an inert gas atmosphere (all other atmospheres also possible) at temperatures from 350 to 1000 ° C or 400 up to 700 ° C or 400 to 650 ° C or 400 to 600 ° C calcined.

Of course, the shape the active compositions also by extrusion and / or tableting of finely divided active mass as well as finely divided precursor mass of active material (if necessary, wash out that of the i phase different phases and / or the elements finally).

As geometries for the full catalysts obtained Both balls, solid cylinders and hollow cylinders (rings) can be considered. The longest dimension of the aforementioned geometries usually 1 to 10 mm. In the case of cylinders, it is Length preferred 2 to 10 mm and their outer diameter preferably 4 to 10 mm. In the case of rings, the wall thickness is also usually more at 1 to 4 mm. Suitable according to the invention annular Full catalysts can also a length from 3 to 6 mm, an outer diameter of 4 to 8 mm and a wall thickness of 1 to 2 mm. Is possible but also a full catalyst ring geometry of 7 mm × 3 mm × 4 mm or of 5 mm × 3 mm × 2 mm (outer diameter × length × inner diameter).

Of course, the geometries of the DE-A 10101695 into consideration.

Of course, the active materials can also in with finely divided, e.g. colloidal, materials such as silicon dioxide, Titanium dioxide, aluminum oxide, zirconium oxide, niobium oxide, diluted form be used as catalytic active materials. The training the thinner can be in the active mass or in one of its precursor masses respectively.

The ones described in this document Active materials are suitable (in powder form or shaped into geometrical shaped bodies, undiluted or diluted) as active masses for heterogeneously catalyzed partial gas phase oxidations (including oxide hydrogenations) and / or amoxidations of saturated and / or unsaturated Hydrocarbons as well as saturated and / or unsaturated Aldehydes.

Such saturated and / or unsaturated Hydrocarbons are especially ethane, ethylene, propane, propylene, n-butane, isobutane and isobutene. Above all, target products are Acetic acid, Vinyl acetate, acrolein, acrylic acid, Methacrolein, methacrylic acid, Acrylonitrile and methacrylonitrile. But they are also suitable for the heterogeneous catalyzed partial gas phase oxidation and / or amoxidation of compounds such as acrolein and methacrolein.

But also ethylene, propylene as well n- and iso-butenes can Be target products.

In this document, complete oxidation of a hydrocarbon is understood to mean that the total carbon contained in the hydrocarbon is converted into oxides of carbon (CO, CO ₂ ).

All of them different implementations of hydrocarbon under the reactive action of molecular Oxygen is used in this document with the term partial oxidation subsumed. The additional reactive The effect of ammonia is characterized by partial ammoxidation.

These are preferably suitable Scripture-based active materials as catalytic active materials for the implementation from n-butane to maleic anhydride, from propane to acrolein and / or acrylic acid, from propane to acrylic acid and / or Acrylonitrile, from propylene to acrolein and / or acolic acid, from Propylene to acrylonitrile, from isobutane to methacrolein and / or methacrylic acid, from isobutane to methacrylic acid and / or methacrylonitrile, from isobutene to methacrolein and / or methacrylic acid, from isobutene to methacrylic acid and / or Methacrylonitrile, from ethane to ethylene, from ethane to acetic acid and / or Vinyl acetate and from ethylene to acetic acid and / or vinyl acetate.

The implementation of such partial oxidations and / or ammoxidations (by controlled in a manner known per se The reaction can be selected by selecting the ammonia content in the reaction gas mixture essentially exclusively as partial oxidation, or exclusively as partial ammoxidation, or as an overlay both reactions are designed; see. e.g. WO 98/22421) is from the i- / k-phase-containing multimetal oxide materials of the cited state the technology known per se and can be carried out in a completely corresponding manner.

Also like in the DE-A 10254279 described procedure.

If crude propane or crude propylene is used as the hydrocarbon, this is preferred as in FIG DE-A 10246119 respectively. DE-A 10118814 or PCT / EP / 02/04073. The same procedure as described there is preferred.

A partial oxidation of propane to acrylic acid can, for example, as in the EP-A 608838 , WO 0029106, the JP-A 10-36311 and the EP-A 1192987 described.

For example, air, oxygen-enriched or can be used as a source of the required molecular oxygen air de-oxygenated or pure oxygen can be used.

Such a process is also advantageous if the reaction gas starting mixture does not contain any proportion of noble gas, in particular no helium, beyond the noble gas content of air, as an inert diluent gas. In addition to propane and molecular oxygen, the reaction gas starting mixture can of course also comprise inert diluent gases such as N ₂ , CO and CO ₂ . Water vapor as a component of the reaction gas mixture is advantageous according to the invention.

That is, the reaction gas starting mixture with which the active composition according to the invention can be loaded at reaction temperatures of, for example, 200 to 550 ° C. or from 230 to 480 ° C. or 300 to 440 ° C. and pressures of 1 to 10 bar or 2 to 5 bar may have the following composition, for example:
1 to 15, preferably 1 to 7% by volume of propane,
44 to 99 vol .-% air and
0 to 55 vol% water vapor.

Water vapor is preferred Starting reaction gas mixtures.

Other possible compositions of the reaction gas starting mixture are:
70 to 95 vol .-% propane,
5 to 30 vol.% Molecular oxygen and
0 to 25 vol% water vapor.

It goes without saying that a product gas mixture which does not consist exclusively of acrylic acid is obtained in such a process. Rather, the product gas mixture contains, in addition to unreacted propane, secondary components such as propene, acrolein, CO ₂ , CO, H ₂ O, acetic acid, propionic acid, etc., from which the acrylic acid must be separated.

This can be done as it is by the heterogeneously catalyzed gas phase oxidation of propene to acrylic acid is.

The multimetal oxide compositions according to the invention can, however, also be integrated into other multimetal oxide compositions (for example, mixing their finely divided compositions, optionally pressing and calcining them, or mixing, preferably aqueous) as slurries, drying and calcining (for example analogously to that EP-A 529853 for the local multimetal oxide materials))). It is preferably calcined again under inert gas.

Examples and comparative examples

Comparative Example 1 [Mo _3.8 V ⁴⁺ _1.2 O _13.8 ]

115.5 g of ammonium metavanadate from HC Starck (V ₂ O ₅ content = 75.6% by weight; 0.96 mol V ⁵⁺ ) became clear in 6000 ml of water at 80 ° C. with nitrogen flushing and with stirring yellowish solution dissolved. Subsequently, 671.1 g of ammonium heptamolybdate tetrahydrate from HC Starck (MoO ₃ content = 81.5% by weight; 3.8 mol Mo) were dissolved in this solution while maintaining the 80 ° C. and the nitrogen purge with stirring. 12.23 g of elementary V powder from ChemPur in 76204 Karlsruhe (100% V; 0.24 mol V ^{± 0} ) were added to the clear aqueous solution obtained while maintaining the nitrogen purge and the 80 ° C. while stirring and then stirring continued for 4 h while maintaining the boundary conditions. The dark blue-black aqueous suspension obtained was cooled to 60 ° C. and stirred at this temperature for a further 12 h while maintaining the nitrogen purge. The aqueous suspension was then spray-dried in a spray dryer from Niro (spray dryer Niro A / S Atomizer, portable minor system, centrifugal atomizer from Niro, DK). The initial temperature was 60 ° C. The gas inlet temperature ^T was 370 ° C, the gas exit temperature ^from T was 105 ° C.

100 g of the spray powder obtained were in a rotary kiln according to 1 the DE-A 10122027 (1 l internal volume) heated under an air flow of 50 Nl / h within 50 min with a linear ramp from 25 ° C to 275 ° C and then kept at 275 ° C for 30 min while maintaining the air flow. The air stream was then replaced by a 50 Nl / h nitrogen stream and linearly heated from 275 ° C. to 575 ° C. within 16 minutes and maintained at this temperature for 360 minutes while maintaining the nitrogen stream. The mixture was then cooled to 25 ° C. while maintaining the nitrogen flow. The associated X-ray diffractogram shows the 1 , It shows no i-phase portion.

Example 1 Cs _0.5 [Mo _3.8 V ⁴⁺ _1.2 O _14.05 ] ₁

The preparation was carried out as in Comparative Example 1. After the 12-hour stirring of the dark blue-black aqueous suspension at 60 ° C., 81.5 g of Cs ₂ CO ₃ from ChemPur in 76204 Karlsruhe (100 %; 0.5 mol Cs) was added and the mixture was then stirred at 60 ° C. for 1 h (all under a nitrogen purge). Thereafter, spray-drying and thermal treatment were carried out as in Comparative Example 1. The associated X-ray diffractogram of the resulting active mass shows the 2 , It shows almost pure i-phase. The relative intensities and positions of the diffraction reflections of the contained i-phase are as follows: there] I [%] 13.33 8th 11.29 18 9.86 19 8.20 6 3,998 100 3,527 22 3,412 45 3, 345 56 3,282 104 3,170 43 3,062 38 2,939 24 2,861 35

Comparative Example 2 [Mo _3.5 V ⁴⁺ ₁ W _0.5 O ₁₄ ]]

115.5 g of ammonium metavanadate from HC Starck (V ₂ O ₅ content = 75.6% by weight; 0.96 mol V ⁵⁺ ) became clear in 6000 ml of water at 80 ° C. with nitrogen flushing and with stirring yellowish solution dissolved. 741.8 g of ammonium heptamolybdate tetrahydrate from HC Starck (MoO ₃ content = 81.5% by weight; 4.2 mol of Mo) were then dissolved in this solution while maintaining the 80 ° C. and the nitrogen purge with stirring. 12.23 g of elementary V powder from ChemPur in 76204 Karlsruhe (100% V; 0.24 mol V ^{± 0} ) were added to the clear aqueous solution obtained while maintaining the nitrogen purge and the 80 ° C. while stirring and then stirring continued for 4 h while maintaining the boundary conditions. The dark blue-black aqueous suspension obtained was cooled to 60 ° C. and stirred at this temperature for a further 12 h while maintaining the nitrogen purge. Then, while continuing the nitrogen purge and the 60 ° C., 156.5 g of ammonium paratungstate heptahydrate from HC Starck (WO ₃ content = 88.90% by weight; 0.6 mol W) were added and the mixture was stirred for 1 hour.

The aqueous suspension obtained was spray-dried as in Comparative Example 1 and 100 g of the spray powder obtained in a rotary ball oven according to 1 the DE-A 10122027 (1 l internal volume) heated under an air flow of 50 Nl / h within 50 min with a linear ramp from 25 ° C to 275 ° C and then kept at 275 ° C for 30 min while maintaining the air flow. The air stream was then replaced by a 50 Nl / h nitrogen stream and heated from 275 ° C. to 600 ° C. within 15 minutes and kept at this temperature for 360 minutes while maintaining the nitrogen stream. The mixture was then cooled to 25 ° C. while maintaining the nitrogen flow. The associated X-ray diffractogram shows the 3 , It shows no i-phase portion.

Example 2 Cs _0.5 [Mo _3.4 V ⁴⁺ _1.2 W _0.4 O ₁₄ ] ₁

115.5 g of ammonium metavanadate from HC Starck (V ₂ O ₅ content = 75.6% by weight; 0.96 mol V ⁵⁺ ) became clear in 6000 ml of water at 80 ° C. with nitrogen flushing and with stirring yellowish solution dissolved. 600.5 g of ammonium heptamolybdate tetrahydrate from HC Starck (MoO ₃ content = 81.5% by weight; 3.4 mol of Mo) were then dissolved in this solution while maintaining the 80 ° C. and the nitrogen purge with stirring. 12.23 g of elementary V powder from ChemPur in 76204 Karlsruhe (100% V; 0.24 mol V ^{± 0} ) were added to the clear aqueous solution obtained while maintaining the nitrogen purge and the 80 ° C. while stirring and then under Maintaining the boundary conditions continued for 4 h. The dark blue-black aqueous suspension obtained was cooled to 60 ° C. and stirred at this temperature for a further 12 h while maintaining the nitrogen purge. 104.3 g of ammonium paratungstate heptahydrate from Starck (WO ₃ content = 88.90% by weight; 0.4 mol W) were then added, while the nitrogen purge and the 60 ° C. were continued, and the mixture was stirred for 1 h. Thereafter, while maintaining the nitrogen purge and the 60 ° C., 81.46 g of Cs ₂ CO ₃ from ChemPur in 76204 Karlsruhe (100%; 0.5 mol Cs) were added and the mixture was stirred for a further hour. The resulting aqueous suspension was spray dried as in Comparative Example 1. Then 100 g of the spray powder were thermally treated as in Comparative Example 2. The associated X-ray diffractogram of the resulting active mass shows the 4 , It shows almost pure i-phase. The relative intensities and positions of the diffraction reflections of the contained i-phase are as follows: there] I [%] 13.29 11 11.19 24 9.79 24 8.16 8th there] I [%] 3,966 100 3,524 20 3,405 39 3, 345 48 3,283 90 3,173 39 3,060 38 2,937 28 2,859 35

Example 3 Cs _0.5 [Mo ₃ , ₅ V ⁺⁴ ₁ Te _0.5 O ₁₄ ] ₁

96.2 g of ammonium metavanadate from HC Starck (V ₂ O ₅ content = 75.6% by weight; 0.8 mol V ⁵⁺ ) became clear in 6000 ml of water at 80 ° C. with nitrogen flushing and with stirring yellowish solution dissolved. 618.2 g of ammonium heptamolybdate tetrahydrate from HC Starck (MoO ₃ content = 81.5% by weight; 3.5 mol of Mo) were then dissolved in this solution while maintaining the 80 ° C. and the nitrogen purge with stirring. 10.19 g of elementary V powder from ChemPur in 76204 Karlsruhe (100% V; 0.2 mol ^{V ± 0} ) were added to the clear aqueous solution obtained while maintaining the nitrogen purge and the 80 ° C. while stirring and then stirring continued for 4 h while maintaining the boundary conditions. The dark blue-black aqueous suspension obtained was cooled to 60 ° C. and stirred at this temperature for a further 12 h while maintaining the nitrogen purge. Thereafter, while continuing the nitrogen purge and the 60 ° C., 114.82 g of Te acid from Fluka (CH-9471 Buchs, 100%; 0.5 mol Te) were added and stirring was continued for 1 h. Then 81.5 g of Cs ₂ CO ₃ from ChemPur (100%; 0.5 mol Cs) were added while maintaining the boundary conditions and the mixture was stirred for a further hour.

The aqueous suspension obtained was spray-dried as in Comparative Example 1 and 100 g of the spray powder obtained in a rotary ball oven according to 1 the DE-A 10122027 (1 l internal volume) heated under an air flow of 50 Nl / h within 50 min with a linear ramp from 25 ° C to 275 ° C and then kept at 275 ° C for 30 min while maintaining the air flow.

The air stream was then replaced by a 50 Nl / h nitrogen stream and heated from 275 ° C. to 600 ° C. within 17 minutes and kept at this temperature for 360 minutes while maintaining the nitrogen stream. The mixture was then cooled to 25 ° C. while maintaining the nitrogen flow. The associated X-ray diffractogram of the active mass shows 5 , It shows significant i-phase proportions. The relative intensities and positions of the diffraction reflections of the contained i-phase are as follows: there] I [%] 13.29 7 11.22 17 9.80 20 8.27 4 4,000 100 3,520 20 3,394 38 3,341 38 3,275 62 3,170 29 3,058 30 2,930 20 2,856 24

Example 4 Cs _0.5 [Mo _3.7 V ⁴⁺ _1.2 Se _0.1 O ₁₄ ] ₁

In 6000 ml of water at 80 ° C. with nitrogen flushing and with stirring, 115.5 g of ammonium metavanadate from HC Starck (V ₂ O ₅ content = 75.6% by weight; 0.96 mol V ⁵⁺ ) became one clear yellowish solution solved. 653.5 g of ammonium heptane molybdate tetrahydrate from HC Starck (MoO ₃ content = 81.5% by weight; 3.7 mol Mo) were then dissolved in this solution while maintaining the 80 ° C. and the nitrogen flushing with stirring. 12.23 g of elementary V powder from ChemPur in 76204 Karlsruhe (100% V; 0.24 mol V ^{± 0} ) were added to the clear aqueous solution obtained while maintaining the nitrogen purge and the 80 ° C. while stirring and then stirring continued for 4 h while maintaining the boundary conditions. The dark blue-black aqueous suspension obtained was cooled to 60 ° C. and stirred at this temperature for a further 12 h while maintaining the nitrogen purge. Thereafter, while continuing the nitrogen purge and the 60 ° C., 12.9 g of selenium acid (H ₂ SeO ₃ ) from Fluka (CH-9471 Buchs; 100%, 0.1 mol Se) were initially added and stirring was continued for 1 h. Then 81.5 g of Cs ₂ CO ₃ from ChemPur (100%; 0.5 mol Cs) were added while maintaining the boundary conditions and the mixture was stirred for a further hour. The aqueous suspension obtained was spray-dried as in Comparative Example 1 and 100 g of the spray powder obtained in a rotary ball oven according to 1 the DE-A 10122027 (1 l internal volume) heated under an air flow of 50 Nl / h within 50 min with a linear ramp from 25 ° C to 275 ° C and then kept at 275 ° C for 30 min while maintaining the air flow. The air stream was then replaced by a 50 Nl / h nitrogen stream and heated from 275 ° C. to 650 ° C. within 20 minutes and maintained at this temperature for 360 minutes while maintaining the nitrogen stream. The mixture was then cooled to 25 ° C. while maintaining the nitrogen flow. The associated X-ray diffractogram of the active composition shows significant i-phase fractions. The relative intensities and positions of the diffraction reflections of the contained i-phase are as follows: there] I [%] 13.23 7 11.24 18 9.82 15 8.16 7 3,998 100 3,528 24 3,401 40 3,347 57 3,281 85 3,170 39 3,060 32 2,938 25 2,860 31

Example 5 Cs _0.5 [Mo _3.5 V ⁺⁴ ₁ Sb _0.5 O ₁₄ ] ₁

120.3 g of ammonium metavanadate from HC Starck (V ₂ O ₅ content = 75.6% by weight; 1 mol V ⁵⁺ ) became a clear yellowish in 6000 ml of water at 80 ° C. with nitrogen flushing and with stirring Solution solved. 618.2 g of ammonium heptamolybdate tetrahydrate from HC Starck (MoO ₃ content = 81.5% by weight; 3.5 mol of Mo) were then dissolved in this solution while maintaining the 80 ° C. and the nitrogen purge with stirring. 45.02 g of anhydrous oxalic acid from Fluka (CH-9471 Buchs; 100%; 0.5 mol oxalic acid) were added to the clear aqueous solution obtained while maintaining the nitrogen purge and the 80 ° C. with stirring and then while maintaining the Boundary conditions continued for 4 h. The dark blue-black aqueous suspension obtained was cooled to 60 ° C. and stirred at this temperature for a further 12 hours while maintaining the nitrogen purge. 72.9 g of antimony (III) oxide from Merck, Darmstadt (100% by weight; 0.5 mol of Sb) were then added while continuing the nitrogen purge and the 60 ° C. and stirring was continued for 1 h.

Then 81.5 g of Cs ₂ CO ₃ from ChemPur in 76204 Karlsruhe (100%; 0.5 mol Cs) were added while maintaining the boundary conditions and the mixture was stirred for a further hour.

The aqueous suspension obtained was as spray-dried in Comparative Example 1 and 100 g of the spray powder obtained thermally treated as in Example 3.

The associated X-ray diffractogram of the active composition shows significant i-phase fractions. The relative intensities and positions of the diffraction reflections of the contained i-phase are as follows: there] I [%] 13.29 3 11.26 7 9.82 6 8.19 2 4,000 100 3,510 13 3,404 17 3,340 17 3,278 33 3,176 21 3,057 15 2,933 13 2,856 15

Example 6 Cs _0.5 [Mo _3.7 V ⁺⁴ _1.2 Bi _0.1 O _13.9 ] ₁

In 6000 ml of water at 80 ° C. with nitrogen flushing and with stirring, 115.5 g of ammonium metavanadate from HC Starck (V ₂ O ₅ content = 75.6% by weight; 0.96 mol V ⁺⁵ ) became one clear yellowish solution. 653.5 g of ammonium heptamolybdate tetrahydrate from HC Starck (MoO ₃ content = 81.5% by weight; 3.7 mol Mo) were then dissolved in this solution while maintaining the 80 ° C. and the nitrogen purge with stirring. 12.23 g of elementary V powder from ChemPur in 76204 Karlsruhe (100% V; 0.24 mol V ^{± 0} ) were added to the clear aqueous solution obtained while maintaining the nitrogen purge and the 80 ° C. while stirring and then stirring continued for 4 h while maintaining the boundary conditions. The dark blue-black aqueous suspension obtained was cooled to 60 ° C. and stirred at this temperature for a further 12 h while maintaining the nitrogen purge. Thereafter, while continuing the nitrogen purge and the 60 ° C., 81.5 g of Cs ₂ CO ₃ from ChemPur in 76204 Karlsruhe (100%; 0.5 mol Cs) were added and stirring was continued for 1 h. Then, while maintaining the boundary conditions, 48.5 g of bismuth nitrate pentahydrate from Riedel de Haen, D-30926 Seelze (100%; 0.1 mol Bi) were added and the mixture was stirred for a further hour. The aqueous suspension obtained was spray-dried as in Comparative Example 1 and 100 g of the spray powder obtained were thermally treated as in Comparative Example 2. The associated X-ray diffractogram of the active mass shows significant i-phase fractions. The relative intensities and positions of the diffraction reflections of the contained i-phase are as follows: there] I [%] 13.28 10 11.23 14 9.80 14 8.11 10 3,990 100 3,533 33 3,407 59 3,346 57 3,279 72 3,173 41 3,059 47 2,934 25 2,863 29

Example 7 Cs _0.5 [Mo _3.2 V ^{+ 4a} ₁ Nb _0.4 Bi _0.4 O _13.45 ] ₁

120.3 g of ammonium metavanadate from HC Starck (V ₂ O ₅ content = 75.6% by weight; 1.0 mol V ⁺⁵ ) became clear in 6000 ml of water at 80 ° C. with nitrogen flushing and with stirring yellowish solution dissolved. Subsequently, 565.2 g of ammonium heptamolybdate tetrahydrate from HC Starck (MoO ₃ content = 81.5% by weight; 3.2 mol Mo) were dissolved in this solution while maintaining the 80 ° C. and the nitrogen purge with stirring. 182.1 g of niobium oxalate from HC Starck (20.41% by weight of Nb; 0.4 mol of Nb) were added to the clear aqueous solution obtained while maintaining the nitrogen purge and the 80 ° C. while stirring and then while maintaining of the boundary conditions continued for 1 h. The resulting dark green solution was cooled to 60 ° C. Thereafter, while continuing the nitrogen purge and the 60 ° C., 194.0 g bismuth nitrate pentahydrate (Bi (NO ₃ ) ₃ .5 H ₂ O) from Riedel de Haen, D-30926 Seelze (100%; 0.4 mol Bi) and then 81.5 g Cs ₂ CO ₃ from ChemPur in 76204 Karlsruhe (100%; 0.5 mol Cs) were added and the resulting suspension was stirred for 20 min. Then it was spray dried as in Comparative Example 1. 100 g of the spray powder obtained were treated thermally as in Example 3. The associated X-ray diffractogram of the active composition shows significant i-phase fractions. The relative intensities and positions of the diffraction reflections of the contained i-phase are as follows: there] I [%] 13.29 5 11.27 10 9.84 8th 8.24 5 4,004 100 3,514 24 3,426 58 3, 348 39 3,275 63 3,178 38 3,057 33 2,939 43 2,856 28

Example 8

100 g of the multimetal oxide mass Cs _0.5 [Mo ₃ , ₅ V ⁺⁴ ₁ Te _0.5 O _x ] ₁ from Example 3 were heated to 85 ° C. in 1 l of 20% strength by weight aqueous HNO ₃ and at this temperature Heated under reflux at normal pressure for 5 h.

After the aqueous suspension had cooled, the Solid content filtered off, five times washed with water and dried in a vacuum drying cabinet at 110 ° C. for 24 h.

The solids analysis gave the composition Cs _0.3 [Mo _3.6 V ₁ Te _0.4 O _y ] ₁ .

The X-ray diffractogram was identical with the X-ray diffractogram of the starting powder, although the Cs content through treatment with aqueous nitric acid around 40 % (relative) was reduced.

Claims (26)

Multimetal oxide mass of the general formula I A _a [Mo _5-bc V _b X _c O _d ] ₁ (I), with A = at least one of the elements from the group comprising NH ₄ , Na, K, Rb, Cs and Tl; X = one or more of the elements from the group comprising La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ti, Zr, Hf, Nb, Ta , W, Mn, Re, Fe, Co, Ni, Cr, Ru, Rh, Pd, Os, Ir, Pt, Cu, Ag, Au, Zn, Cd, Hg, B, Al, Ga, In, C, Si , Ge, Sn, Pb, P, As, Sb, Bi, S, Se and Te; a = 0.1 to 1; b = 0.25 to 4.5; and c = 0 to 4.5, with the proviso that b + c ≤ 4.5, whose X-ray diffractogram represents the subsequent X-ray diffraction pattern RM, represented in the form of network plane distances d [Å], d [Å] that are independent of the wavelength of the X-ray radiation used. 3.06 ± 0.2 3.17 ± 0.2 3.28 ± 0.2 3.99 ± 0.2 9.82 ± 0.4 11.24 ± 0.4 13.28 ± 0.5, contains. Multimetal oxide mass according to claim 1, wherein the X-ray diffraction pattern RM additionally the following, based on the intensity of the network plane distance 308/2003 Mr / do 12.05.2003 1 to 5 d [Å] = 3.99 ± 0.2 representative diffraction reflex related relative diffraction reflex intensities I (%) has: there] I (%) 3.06 ± 0.2 5 to 65 3.17 ± 0.2 5 to 65 3.28 ± 0.2 15 to 130 3.99 ± 0.2 100 9.82 ± 0.4 1 to 50 11.24 ± 0.4 1 to 45 13.28 ± 0.5 1 to 35. Multimetal oxide composition according to claim 1 or 2, in which A is at least one of the two elements Rb and Cs. Multimetal oxide composition according to one of claims 1 to 3, in which X comprises one or more of the elements from the group Ti, Cr, W, Mn, Re, Fe, Co, Ni, Pd, Pt, Cu, Ag, Ga, Sn, Sb and Te is. Multimetal oxide composition according to one of claims 1 to 4, in which c = 0.05 to 4.0. Multimetal oxide composition according to one of claims 1 to 5, in which b = 0.5 to 2.5. Multimetal oxide composition according to one of claims 1 to 6, in which a = 0.2 to 0.8. Multimetal oxide composition according to one of claims 1 to 7, in which a = 0.3 to 0.7. Multimetal oxide composition according to one of claims 1 to 8, in which the V therein contains more than 25 mol% in the oxidation state +4 is present. Multimetal oxide composition according to one of claims 1 to 9, in which the V contained therein is more than 50 mol% in the oxidation state +4 is present. Multimetal oxide composition according to one of claims 1 to 10, whose X-ray diffractogram in addition contains the following diffraction reflexes: there] 8.19 ± 0.3 3.51 ± 0.2 3.42 ± 0.2 3.34 ± 0.2 2.94 ± 0.2 2.86 ± 0.2. The multimetal oxide composition according to claim 11, wherein the additional diffraction reflections have the following relative diffraction reflex intensities I (%), based on the intensity of the diffraction reflex representing the network plane spacing d [A] = 3.99 ± 0.2: there] I (%) 8.19 ± 0.3 0 to 25 3.51 ± 0.2 2 to 50 3.42 ± 0.2 5 to 75 3.34 ± 0.2 5 to 80 2.94 ± 0.2 5 to 55 2.86 ± 0.2 5 to 60. Multimetal oxide composition according to one of claims 1 to 12, whose X-ray diffractogram in addition contains the following diffraction reflexes: there] 2.54 ± 0.2 2.01 ± 0.2 The multimetal oxide mass according to claim 13, wherein the additional diffraction reflections relate to the following diffraction reflex, which represents the intensity of the network plane spacing d [Å] = 3.99 ± 0.2 gene, relative diffraction reflex intensities I (%) have: there] I (%) 2.54 ± 0.2 0.5 to 40 2.01 ± 0.2 5 to 60. Multimetal oxide composition according to one of claims 1 to 14, in their X-ray diffractogram which is the network plane distance d [Å] = 3.99 ± 0.2 or the diffraction reflex representing the network plane distance d [Å] = 3.28 ± 0.2 the most intense diffraction reflex is. Multimetal oxide composition according to one of claims 1 to 15, in their X-ray diffractogram which is the network plane distance d [Å] = 3.99 ± 0.2 representing Diffraction reflex has a 2⊝ half-value width ≤ 1 °. Process for producing a multimetal oxide mass according to one of the claims 1 to 16, characterized in that one from suitable sources a dry mixture of the elementary constituents of the multimetal oxide mass generated and this thermally at temperatures of 350 to 1000 ° C. treated. A method according to claim 17, characterized in that the thermal treatment takes place under inert gas. Process for producing a multimetal oxide mass according to one of the claims 1 to 18, characterized in that one from suitable sources a dry mixture of the elementary constituents of the multimetal oxide mass generated this first in an oxidizing atmosphere at a temperature of 150 to 400 ° C and then under Inert gas thermally treated at a temperature of 350 to 1000 ° C. Method according to one of claims 17 to 19, characterized in that that used to make the dry mix as sources for the element V is a mixture of at least one compound that contains the element V contains +5 in the oxidation state, and elemental vanadium is used. Process for the production of multimetal oxides, characterized in that first a multimetal oxide according to a of claims 1 to 16 and subsequently its content of elements A reduced relative to the Mo content. Process for the production of multimetal oxides, characterized in that first a multimetal oxide according to a of claims 1 to 16 and then treated with a liquid. A method according to claim 22, characterized in that the liquid an organic acid, an inorganic acid or an aqueous one solution such acids is. Multi-metal oxide available by one process according to one of claims 21 to 23. Multimetal oxide available according to one of the processes according to one of claims 21 to 23, that a) no Nb, or b) no Te, or c) no Sb, or d) no Nb and no Te, or e) no Nb and no Sb contains. Use of a multimetal oxide composition according to claims 1 to 16 or according to claim 24 or 25 or an immediate product of the process by a method according to claims 17 to 23 as a catalytic active material for heterogeneously catalyzed partial Gas phase oxidations and / or amoxidations of saturated and / or unsaturated Hydrocarbons as well as saturated and / or unsaturated Aldehydes.