DE4405514A1 - Multi:metal oxide useful as catalyst esp. in gas phase oxidn. of acrolein to acrylic acid - Google Patents

Abstract

Multimetal oxide compsn. of formula (I) is new: (A)p (B)q (I): A = Mo12VaX<1>bX<2>cX<3>dX<4>eX<5>fX<6>gOx (co-phase); B = X<7>12CuhHiOy (key phase); X<1> = W, Nb, Ta, Cr and/or Ce; X<2> = Cu, Ni, Co, Fe, Mn and/or Zn; X<3> = Sb and/or Bi; X<4> = Li, Na, K, Rb, Cs and/or H; X<5> = Mg, Ca, Sr and/or Ba; X<6> = Si, Al, Ti and/or Zr; X<7> = Mo, W, V, Nb and/or Ta; a = 1-8; b = 0.2-5; c = 0-23; d, g = 0-50; e = 0-2; f = 0-5; h = 4-30; i = 0-20; x, y = values depending on the valency and content of elements other than O; p, q = values other than O, with the ratio p/q = 160:1 to 1:1. The A and B fractions are each in the form of 30 zones, which differ in chemical compsn. from their local surroundings, and the relative distribution of the A and B zones is as in a mixt. of finely-divided A and finely-divided B. Also claimed are multimetal oxide compsns. of wolframite structural type, of formulae (II), (III), (IV) and (V): in (II), 1/(A+B+C+D+E) = 0.7-1.3; F = 0-1; and B+C+D+E = over 0 to 1. In (III), 1/(A+B+C) = 0.7-1.3; A, B, C all = more than O and B+C = at most 1; In (IV), 1/(A+B) = 0.7-1.3; A, B both = more than O and B = at most 1; In (V), 1/(A+C) = 0.7-1.3; A, C both - more than O and C - at most 1.

Description

The invention relates to multimetal oxide compositions of the general For mel I

[A] _p [B] _q (I),

in which the variables have the following meaning:

A: Mo₁₂ V _a X _b X _c ¹ ² ³ X _d X _e X _f ⁴ ⁵ ⁶ X _g O _x (Co phase),

B: X₁₂⁷ Cu _h H _i O _y (key phase),

X¹ W, Nb, Ta, Cr and / or Ce, preferably W, Nb and / or Cr,
X 2 is Cu, Ni, Co, Fe, Mn and / or Zn, preferably Cu, Ni, Co and / or Fe,
X³ Sb and / or Bi, preferably Sb,
X⁴ Li, Na, K, Rb, Cs and / or H, preferably Na and / or K,
X⁵ Mg, Ca, Sr and / or Ba, preferably Ca, Sr and / or Ba,
X⁶ Si, Al, Ti and / or Zr, preferably Si, Al and / or Ti,
X⁷ Mo, W, V, Nb and / or Ta, preferably Mo,
a 1 to 8, preferably 3 to 6,
b is 0.2 to 5, preferably 0.5 to 2.5,
c is 0 to 23, preferably 0 to 4,
d is 0 to 50, preferably 0 to 3,
e is 0 to 2, preferably 0 to 0.3,
f 0 to 5, preferably 0 to 2,
g is 0 to 50, preferably 0 to 20,
h is 4 to 30, preferably 6 to 24, particularly preferred 9 to 17,
i is 0 to 20, preferably 0 to 10,
x, y are numbers determined by the valency and frequency of elements other than oxygen in I and
p, q are non-zero numbers whose ratio p / q is 160: 1 to 1: 1, preferably 20: 1 to 1: 1 and more preferably 15: 1 to 4: 1,
the proportion [A] _p in the form of three-dimensional extended, of their local environment due to their different chemical composition different from their local environment, areas A of the chemical composition

A: Mo₁₂ V _a X _b ¹ X _c ² X _d ³ X _e ⁴ X _f ⁵ X _g ⁶ O _x

and the proportion [B] _q in the form of three-dimensionally extended areas B of the chemical composition delimited from their local environment because of their chemical composition different from their local environment

B: X₁₂⁷ Cu _h H _i O _y

contain, wherein the areas A, B relative to each other as in a mixture of finely divided A and finely divided B distributed are.

Moreover, the present invention relates to methods of preparation these masses and their use.

DE-A 43 35 973 and US-A 4 035 262 relate to multimetal oxide compositions whose elemental gross composition of those of corresponds to the invention Multimetalloxidmassen. The manufacturer Development of these multimetal oxide materials is carried out by adding geei suggested sources of the constituents of the desired multimetal oxide in the required quantities to an intimate dry processed and then this at elevated Temperature calcined for several hours. The resulting multi metal oxide materials are used as catalysts for gas phase catalytic table oxidative production of acrylic acid from acrolein recommended len. A disadvantage of the Multimetalloxidmassen this state of the Technique, however, is that in their use the selectivity of Acrylic acid formation at a given Acroleinumsatz not fully closed can satisfy. Furthermore, these multimetal oxide materials have a pronounced formation behavior. That when using freshly prepared multimetal oxide reaches the Selectivity (for a given acrolein conversion) of the acrylic acid education only after a longer period of operation then their essenli stationary stationary value. Also, reproducibility is possible  their production with respect to the stationary final value of Selectivity of acrylic acid formation is unsatisfactory.

EP-A 835, DE-C 33 38 380, DE-A 42 20 859 and the äl Tere application DE-A 43 07 381 (O.Z. 0050/43890) relate just if as catalysts for the gas phase catalytically oxidative Preparation of α, β-monoethylenically unsaturated carboxylic acids suitable Neten Multimetalloxidmassen, the same in an advantageous manner if they have a key phase / co-phase structure. Although included The general formulas of this prior art are within a wide variety of possible multimetal oxide materials formally also those whose key phase in addition to elements such as Mo lybdenum or tungsten simultaneously contain the element copper However, the entirety of all embodiments includes not a single such embodiment, but selbige are limited to those whose key phase instead of the element Copper contains the element bismuth. This embodiment the state of the art recommends more emphatically than the most preferred. A disadvantage of this preferred embodiment of the However, prior art is that they too as a catalyst for the catalytic gas phase oxidation of acrolein to acrylic acid with regard to the selectivity of acrylic acid formation in vorgege can not fully satisfy the acrolein turnover.

The object of the present invention was therefore multimetal oxide To provide masses that are the disadvantages of the multi metal oxide compositions of the prior art do not have. Demge According to the initially defined masses I were found.

Very particularly preferred compounds I are those whose regions A a composition according to the following general For have mel II

Mo₁₂ V _{a '} X _b' ¹ X _{c '} ² X _f' ⁵ X _{g '} ⁶ O _x' (II)

With
x¹ W and / or Nb,
x² Cu and / or Ni,
X⁵ Ca and / or Sr,
X⁶ Si and / or Al,
a '3 to 6,
b '1 to 2,
c '1 to 3,
f '0 to 0, 75,
g '0 to 10 and
x 'is a number determined by the valence and frequency of the elements other than oxygen in II.

Furthermore, it is advantageous if the proportion [B] _{q of} the multimetal oxide compositions according to the invention is contained in the latter in the form of three-dimensional regions of the chemical composition B whose largest diameter d _B (longest connecting section extending through the center of gravity of the region on the surface (Interface) of the area located points) <0 to 300 .mu.m, preferably 0.1 to 200 .mu.m, more preferably 0.5 to 50 microns and most preferably 1 to 30 microns. Of course, however, the maximum diameters may also be 50 to 150 μm or 75 to 125 μm (the experimental determination of the maximum diameter permits, for example, the method of energy dispersive X-ray analysis (EXDS), for example by means of an electron beam microprobe JEOL JCXA / 733).

The proportions [A] _p , [B] _q can be present in the multi-metal oxide compositions according to the invention in each case amorphous and / or crystalline. The proportion [B] _q is preferably present in crystalline form. In this case, those multimetal oxide compositions are preferred whose regions B consist essentially of crystallites which have the X-ray diffraction pattern (the structure type) of at least one of the following copper molybdate (the expression in parentheses represents the source for the associated X-ray diffraction fingerprint):
Cu₃ (MoO₄) ₂ (OH) ₂ (Lindgrenit, tab 36-405 of the JCPDS-ICDD I file 1991)),
Cu₄ Mo₆ O₂₀ (A. Moini et al., Inorg. Chem. 25 (21) (1986) p. 3782 to 3785),
Cu₄ Mo₅ O₁₇ (tab 39-181 of the JCPDS-ICDD file (1991)),
Cu₆ Mo₅ O₁₈ (file 40-865 of the JCPDS-ICDD file (1991)),
Cu₆ Mo₄ O₁₅ (tab 35-17 of the JCPDS-ICDD file (1991)),
Cu Mo O₄ (tab 22-242 of the JCPDS-ICDD file (1991)),
Cu _4-x Mo₃ O₁₂ with x = 0 to 0.25 (tabs 24-56 and 26-547 of the JCPDS-ICDD file (1991)),
Cu₃ Mo₂ O₉ (tabs 24-55 and 22-609 of the JCPDS-ICDD file (1991)),
Cu₂Mo O₅ (tab 22-607 of the JCPDS-ICDD file (1991)).

Preferably, the proportion [B] _{q of} the multi-metal oxide compositions according to the invention consists of at least one of these Kupfermolybdate itself.

Cheap multimetal oxide compositions according to the invention are also those their ranges B crystallites of oxometalates of the general Formula III

Cu Mo _A W _B V _C Nb _D Ta _E O _y · (H₂O) _F (III)

With
1 / (A + B + C + D + E) 0.7 to 1.3, preferably 0.85 to 1.15, more preferably 0.95 to 1.05 and most preferably 1,
F 0 to 1,
B + C + D + E 0 to 1, preferably 0 to 0.5, more preferably 0 to 0.1 and most preferably 0 and
Y is a number which is determined by the valency and frequency of the elements other than oxygen in III,
a new type of structure, which is defined below by its X-ray diffraction pattern (fingerprint). Reproduced in terms of the wavelength of the X-ray radiation used independent lattice spacings d [Å] are the most characteristic and intense diffraction lines of the new structural type:

there] Intensity [%] 3.14 100 3.01 97.6 2.44 64.9 2.82 57.1 2.75 56.4 3.39 50.1 1.72 41.9   1.65 36.9 2.50 36.1 3.96 33.1 1.80 27.4 1.59 25.7 2.48 25.5 1.61 25.4 1.70 24.9 1.89 24.2 2.20 21.9 1.86 21.7 2.90 21.1 1.96 20.7 2.08 20.6 2.34 20.3 4.68 17.0 2.12 16.7 1.98 16.4 2.00 16.4 1.88 16.3 2.04 15.3 3.71 14.9 3.75 14.7 2.30 13.5 2.37 11.4 3.31 11.3

The intensity data are relative reference values and the highest in intensity Refracted diffraction line. The associated Diffraction angles Θ result from the Bragg relationship:

sin Θ = λ / 2 d,

where λ is the wavelength used for X-ray diffraction X-radiation is. The above information goes back to one Powder absorption on an oxometalate Cu-Mo-O with a Cu / Mo Ratio of about 1. The corresponding radiograph was taken with a Siemens diffractometer D-5000 using Cu Kα radiation (40 kV, 30 mA, λ = 1.5406 Å). The Dif fractometer was with automatic divergence, scattered beam and Counter tube aperture and a Peltier detector equipped. The Un  accuracy of specifying the lattice spacing d amounts to ± 0.20 Å. Regarding the indication of the line intensities be ver notices that the relative line intensities, unlike the Location of the lines through which at different powder intake Preparations based on the anisotropy of the crystal form, adjusting individual crystallite alignments in the compartment man in a known manner be noticeably influenced and therefore to identify the new structure type a smaller Signifi have kanz.

Below are crystallites of oxometallates III of the first defined as the new type of structure as crystallites B * be drawn. According to the ibid remarks are Accordingly, such crystallites B * of particular advantage, the Stö stoichiometry

Cu Mo _A O _y · (H 2 O) _F (IV),

With
1 / A 0.7 to 1.3, preferably 0.85 to 1.15, particularly preferably 0.95 to 1.05 and very particularly preferably 1,
F0 to 1 and
Y is a number determined by the valence and frequency of the elements other than oxygen in IV,
respectively.

The greater the proportion of crystallites B * in the total proportion [B] _q of the novel multimetal oxide compositions, the more advantageous multimetal oxide compositions according to the invention are present. Advantageously, the proportion of crystallites B *, based on the total mass of the fraction [B] _q , amounts to at least 25% by weight. Preferably, the aforesaid proportion is at least 50% by weight, more preferably at least 75% by weight and most preferably at least 90% by weight.

Of course, the most advantageous is a weight fraction of 95 to 100% by weight.

The inventive compositions I are in a simple manner z. B. there obtainable by reacting oxometalates

X₁₂⁷ Cu _h H _i O _y (B)

in finely divided form prefers (starting material 1) and on closing the starting material 1 with suitable sources of elemen constituents of oxometalates A

Mo₁₂ V _a X _b ¹ X _c ² X _d ³ X _e ⁴ X _f ⁵ X _g ⁶ O _x (A)

brings in intimate contact in the desired ratio and a resulting dry mixture at a temperature of 250 calcined to 450 ° C, wherein the calcination under inert gas z. B. N₂), a mixture of inert gas and oxygen (eg., Air), reducing gases such as hydrocarbons (eg methane), aldehydes (eg acrolein) or ammonia as well under a mixture of O₂ and reducing gases (eg. All of the above) can take place, as for example in the DE-A 43 35 973 (earlier application O.Z. 0050/44403) becomes. When calcining under reducing conditions to note that the metallic constituents are not up to the Element to be reduced. The calcination period extends into usually over a few hours and usually increases with you from the calcining temperature. Essential for the sources of elemental constituent of the oxometallate A is, as all common knowledge, only that it is either already han oxides delt or to such compounds by heating, at least in the presence of oxygen, are convertible into oxides. Next The oxides are therefore mainly used as starting compounds Halides, nitrates, formates, oxalates, acetates, carbonates or Hydroxides into consideration. Suitable starting compounds of Mo, V, W and Nb are also their oxo compounds (molybdates, vanadates, Tungstates and niobates) or the acids derived therefrom.

Oxometalates B can in simpler, the expert known per se ter way z. B. be prepared by that of suitable Sources of their elementary constituents as intimate as possible, preferably produces finely divided, dry mixture and this at Temperatures of 200 to 1000 ° C, preferably 250 to 600 ° C, be especially preferably 300 to 500 ° C, calcined for several hours, wherein in terms of calcination time, calcination atmosphere and Ele  the above applies. Here can ge there calcination atmospheres additionally comprise water vapor.

The intimate mixing of the starting compounds in the context of Her Oxometallates B may be dissolved in dry or wet Form done. If it is done in dry form, the output compounds expediently used as finely divided powder and after mixing and optionally compacting the calci subjugated. Preferably, the intimate mixing takes place but in wet form. Usually, the Ausgangsverbin in the form of an aqueous solution and / or suspension mixed together. Subsequently, the aqueous mass is ge dried and calcined after drying. Preferably, the Drying process immediately after completion the aqueous mixture and by spray drying (the Austrittstem temperatures are generally 100 to 150 ° C).

In a preferred production variant of the oxometallate B takes place the thermal treatment of the intimate mixture used Starting compounds in an overpressure vessel (autoclave) in the case of its from under superatmospheric pressure standing water vapor at temperatures in the range of <100 to 600 ° C. The printing area typically extends up to 500 atm, preferably up to 250 atm. Of course, tempera Temperatures above 600 ° C and pressures above 500 atm angewen det, which is application-wise, however, little useful. This hydrothermal treatment is particularly advantageous under such conditions, among which are water vapor and liquid Water coexist. This is in the temperature range of <100 ° C to 374.15 ° C (critical temperature of the water) using the appropriate prints possible. The amounts of water are thereby appropriately sized so that the liquid phase the total amount the starting compounds aufzuneh in suspension and / or solution men can. However, such a procedure is also possible in which the intimate mixture of the starting compounds with the Water vapor in equilibrium amount of liquid water completely absorbed. With advantage is during the hydrotherma len treatment. For the hydrothermal manufacturing variant kom as starting compounds, in particular all those in Be costume that when heated under pressure with water oxides and / or To form hydroxides. Preferably, as Starting compounds already oxides and / or hydroxides of elemen tary constituents, and it is particularly favorable emanating from the elemental oxides. Usually you will get them in use finely divided form.  

The result of the hydrothermal variant usually includes Kri stallite B *.

If one chooses the stö in the hydrothermal production route chiometric composition of the elemental constituents according to of general formula III, as a rule, crystallites B * with advantage.

The hydrothermal treatment typically takes several Hours to complete. After completion of the hydrothermal treatment can the autoclave the insoluble in water oxometalate B ent taken and after drying in a finely divided starting material 1 be transferred.

The intimate contacting of the starting material 1 with the sources The oxometallate A (starting material 2) can be both dry and wet done. In the latter case, only care has to be taken be that the preformed oxometalate B does not go into solution. In an aqueous medium, the latter is not too extreme pH values usually guaranteed. Is the intimate contact brin wet, then normally becomes a dry mass dried (preferably spray-drying). Such a dry matter accumulates automatically during dry mixing.

As possible mixture variants thus come z. B. into consideration:

• a) a dry, finely divided, preformed oxometalate B with dry, finely divided starting compounds of the elementary Constituents of the desired oxometallate A in the desired Amount ratio in a mixer, kneader or in a mill Mix;
• b) a finely divided oxometalate A preform by intimate Mi suitable starting compounds of their elementary con substituents (dry or wet) and then calcined the resulting intimate dry blend at Tempe temperatures of 250 to 450 ° C (with respect to Calcinationdauer, Cal The atmosphere of cination and element sources applies on page 8 predicted); make the preformed oxometalate A finely divided and with the finely divided preformed oxometalate B in ge desired ratio as in a) mix; at this wed Variant is a final calcination of the resul mixture is not essential.
• c) in an aqueous solution and / or suspension of starting connections of the elementary constituents of the desired Oxometallates A the required amount of preformed  Stir in Oxometalates B and then spray dry; Of course, instead of the starting compounds of elemental constituent of the desired oxometallate A also an already according to b) preformed oxometalate A itself be used.

Of course, all between a), b) and / or c) lying Mixing variants are applied. The resulting heartfelt Dry mixture can then be calcined as described and then be shaped to the desired catalyst geometry or vice versa. In principle, the calcined (or application of mixture variant b) optionally uncalcined) Trockenge but also used as a powder catalyst.

Our own investigations have shown that the calcination of the Starting material 1 and the starting material 2 comprising Trockengemi sches the preformed oxometalate B either as such erhal remains (this is especially true in the case of an oxometallate B * the case) or partially or completely into other oxometal late B is converted. A fusion of the components of Starting material 1 with those of the starting material 2 is found in essentially not take place.

This opens up the possibility of grinding the preformed oxo metalate B (eg by wet or dry milling, eg in the Ku gelmühle or by jet milling) from the available, in usually consisting of essentially spherical particles Powder, the grain class with an in for the mass I desired Largest diameter range lying grain size diameter (in the Rule <0 to 300 microns, preferably 0.1 to 200 microns, especially be preferably 0.5 to 50 μm and very particularly preferably 1 to 30 μm) by classifying to be performed in a manner known per se (For example, wet or dry screening) to separate and so to manufacture tailoring the desired multimetal oxide composition put.

When using the multimetal oxide compositions according to the invention as Catalysts for the gas-phase catalytic oxidation of Acrolein to acrylic acid is the shaping to the desired Catalyst geometry preferably by applying to pre formed inert catalyst supports, wherein the application before or after the final calcination can take place. It can the usual carrier materials such as porous or nonporous Aluminas, silica, thoria, zirconia, Silicon carbide or silicates such as magnesium or aluminum silicate be used. The carrier bodies can be regular or unre be shaped regularly, with regularly shaped carrier body with  clearly trained surface roughness, z. B. balls or Hollow cylinder, to be preferred. Among these are again balls especially advantageous. Of particular advantage is the use of substantially non-porous, surface rough, spherical Steatite carriers whose diameter is 1 to 6 mm, preferably 4 to 5 mm. The layer thickness of the active composition is zweckmäßi as in the range 50 to 500 microns, preferably in the range 150th up to 250 μm, selected. It should be attached to this point showed that in the preparation of such coated catalysts for Coating the carrier body to be applied powder mass in usually moistened and after application, z. B. by means of hotter Air, dried again.

The coating of the carrier body is used to produce the Shell catalysts usually in a suitable rotatable Run container as he z. B. from DE-A 29 09 671 or from EP-A 293859 is previously known. In general, the relevant Calcined mass before the carrier coating.

Conveniently, the coating and calcination ver drive in accordance with EP-A 293 859 in a conventional manner so ange that the resulting multimetal oxide active a specific surface of 0.50 to 150 m² / g, a specifi beautiful pore volume of 0.10 to 0.90 cc / g and such pores have diameter distribution that on the diameter ranges 0.1 to <1 μm, 1.0 to <10 μm and 10 μm to 100 μm in each case we at least 10% of the total pore volume accounted for. Preferably become the pores mentioned in EP-A 293 859 as preferred diameter distributions set.

Of course, the multimetal oxide according to the invention masses can also be operated as full catalysts. In this regard, becomes the initial mass 1 and 2 comprehensive intimate dry mixture preferably directly to the desired Katalysatorgeo compressed (eg tableting, extruding or strand press), where appropriate, conventional per se, for. B. Graphite or stearic acid as a lubricant and / or form auxiliary and reinforcing agents such as glass microfibers, asbestos, Silicon carbide or potassium titanate can be added, and calcined. In general, calcining can also be done before molding become. Preferred Vollkatalysatorgeometrie are hollow cylinder with an outer diameter and a length of 2 to 10 mm and a Wall thickness from 1 to 3 mm.

The multimetal oxide compositions according to the invention are suitable for the special as catalysts with increased selectivity (at pre sales) for the gas-phase catalytic oxidation of  Acrolein to acrylic acid. Normally, in the process Acrolein used by the catalytic gas phases oxidation of propene was generated. In general, the Acrolein-containing reaction gases of this propene oxidation without Intermediate cleaning used. Usually, the gas phases catalytic oxidation of acrolein in tube bundle reactors as heterogeneous fixed bed oxidation carried out. As oxidizing agent is oxygen in a conventional manner, expediently with diluted inert gases used. Suitable diluent gases are z. B. N₂, CO₂, hydrocarbon, recycled reaction gases and / or water vapor. In general, the acrolein oxidation an acrolein: oxygen: water vapor: inert gas volume ratio of 1: (1 to 3): (0 to 20): (3 to 30) preferably 1: (1 to 3): (0.5 to 10): (7 to 18). The reaction pressure is generally 1 to 3 bar and the total space load is preferably 1000 to 3500 Nl / l / h. Typical multi-tube Fixed bed reactors are z. B. in the documents DE-A 28 30 765, DE-A 22 01 528 or US Pat. No. 3,147,084. The reaction stems is usually chosen so that the acrolein sales at easy passage above 90%, preferably above 98%, lies. Normally, this reaction temperatures of 230 to 330 ° C required.

Remarkably, the multimetal of the invention oxide masses in the context of gas-phase catalytic oxidation of Acrolein to acrylic acid with respect to the selectivity of acrylic acid formation also has a reduced formation time; d. H. becomes a tube charged with the multimetal oxide compositions of the invention bundle reactor under the above conditions with a Acrolein-containing gas stream for the purpose of oxidative formation Operated by acrylic acid, it achieves the selectivity of acrylic Acid formation already within a reduced operating time their plateau value. Regarding this plateau value has the Production of the multimetal oxide compositions according to the invention via a increased reproducibility.

In addition to the gas-phase catalytic oxidation of acrolein to acrylic but also the inventive process products can acid the gas phase catalytic oxidation of other organic Compounds such as in particular other, preferably 3 to 6 C Atoms, alkanes, alkanols, alkanals, alkenes and alkenes nols (for example propylene, methacrolein, tert-butanol, methyl ethers of tert-butanol, isobutene, isobutane or isobutyraldehyde) olefinically unsaturated aldehydes and / or carboxylic acids, as well as the corresponding nitriles (ammoxidation, especially of propene to acrylonitrile and isobutene or tert. Butanol to methacrylic to catalyze nitrile). An example is the production  of acrolein, methacrolein and methacrylic acid. They are suitable but also for the oxidative dehydrogenation of olefinic compounds.

Conversion, selectivity and residence time are in this document, unless otherwise stated, defined as follows:

Examples a) Preparation of multimetal oxide compositions M according to the invention and Multimetal oxide compositions MV for comparison

MV1: 127 g of copper (II) acetate monohydrate were dissolved in 2700 g of water solved to a solution I. In 5500 g of water were added 95 ° C successively 860 g of ammonium heptamolybdate tetrahydrate, 143 g of ammonium metavanadate and 126 g of ammonium parawolfra matheptahydrate dissolved to a solution II. Subsequently Solution I was stirred into Solution II all at once and the aqueous mixture at an exit temperature of 110 ° C spray dried. Thereafter, the spray powder per kg Kneaded the powder with 0.15 kg of water. The plasticine became in one with an oxygen / nitrogen mixture be sent convection oven calcined. The oxygen content was adjusted so that at the output of the circulating air Often an O₂ content of 1.5 vol .-% was. As part of the Calcination was the plasticine first with a Ge speed of 10 K / min heated to 300 ° C and on closing held for 6 h at this temperature. It was then fired at a rate of 10 K / min 400 ° C heated and this temperature for 1 h upright receive. For adjusting the ammonia content of Calci nierungsatmosphäre the furnace loading O (g Kata  lysator precursor per l internal volume of the recirculating oven), the Input volume flow ES (Nl / h) of the oxygen / nitrogen Mixture and the residence time VZ (sec) the oxygen / stick Stoff-feed (ratio of inner volume of Convection oven and volume flow of the supplied oxygen / stick substance mixture) as listed below chooses. The circulating air oven used had an internal volume of 3 l.

O: 250 g / l,
VZ: 135 sec and
ES: 80 Nl / h.

The resulting catalytically active material is based on the following stoichiometry:
Mo₁₂V₃W _1.2 Cu _1.6 O _x .

After grinding the calcined, catalytically active Material to particle diameter in the range of 0.1 to 50 microns were with the resulting Aktivmassenpul ver in a rotary drum nonporous, rough surface Stea Titkugeln a diameter of 4 to 5 mm in one Quantity of 50 g powder per 200 g steatite balls at the same early addition of 18 g of water coated. Subsequently was dried with 110 ° C hot air.

M1: initial mass 1:
According to A. Moini et al., Inorg. Chem. 25 (21) (1986) p. 3782 to 3785, in particular p. 3782 to p. 3783, Cu₄Mo₆O₂₀ was prepared in finely divided form (number average grain diameter = 8 microns).

Starting weight 2:
Aqueous solution of ammonium heptamolybdate tetrahydrate, ammonium metavanadate and ammonium paratungstate heptahydrate in quantities such that the aqueous solution was based on the following elemental stoichiometry:
Mo₁₂V _3.75 W _1.5 .

From the initial mass 1 was so much in the output 2, that the molar ratio of the Stoichiometric units 0.4 (Aus 1) to 0.8 (starting weight 2).  

Subsequently, the aqueous mixture was as in MV1 spray dried and to a coated catalyst white further processed.

M2: initial mass 1:
According to EM McCarron III and JC Calabrese, J. Solid State Chem. 65 (1986) pp. 215 to 224, especially pp. 215 to 216, Cu₄Mo₅O₁₇ (tab 39-181 of the JCPDS-ICDD file (1991) was prepared in finely divided form (number average grain diameter = 8 microns).

Starting weight 2:
Aqueous solution as in M1, but the underlying elemental stoichiometry was:
Mo₁₂V _3.6 W _1.44 .

From the initial mass 1 was so much in the output 2, that the molar ratio of the Stoichiometric units 0.4 (Aus 1) to 0.83 (starting weight 2).

Subsequently, the aqueous mixture was as in MV1 spray dried and to a coated catalyst white further processed.

M3: starting mass 1:
According to EM McCarron III u. JC Calabrese, J. Solid State Chem. 62 (1986) pp 64 to 74, in particular p. 65, Cu₆Mo₅O₁₈ (file card 40-865 of the JCPDS-ICDD file (1991) in finely divided form Herge (number average grain diameter = 8 microns ).

Starting weight 2:
Aqueous solution as in M1, but the underlying elemental stoichiometry was:
Mo₁₂V _3.37 W _1.35 .

From the initial mass 1 was so much in the output 2, that the molar ratio of the Stoichiometric units 0.27 (Aus 1) to 0.89 (starting weight 2).  

Subsequently, the aqueous mixture was as in MV1 spray dried and to a coated catalyst white further processed.

M4: starting mass 1:
According to K. Nassau u. JW Shiever, J. Am. Ceram. Soc. 52 (1) (1969) pp. 36 to 40, in particular p. 36, CuMoO₄ (index card 22-242 of the JCPDS-ICDD file (1991)) was produced in finely divided form (number-average particle diameter = 8 μm).

Starting weight 2:
Aqueous solution as in M1, but the underlying ele ment stoichiometry was:
Mo₁₂V _3.46 W _1.38 .

From the initial mass 1 was so much in the output 2, that the molar ratio of the aforementioned stoichiometric units 1.6 (Aus 1) to 0.87 (starting weight 2).

Subsequently, the aqueous mixture was as in MV1 spray dried and to a coated catalyst white further processed.

M5: starting mass 1:
In 500 ml of water were 55.3 g of Cu (II) oxide (CuO, Fa. Merck, Darmstadt, reinst, at least 96%, powdered) and 100.0 g of Mo (VI) oxide (MoO₃, Fa. Merck , Darmstadt, Pa, at least 99.5%, in powder form). The total amount of the aqueous dispersion was heated to 350 ° C. in an autoclave (material: Hastelloy C4, inner volume: 2.5 l) with stirring (1000 rpm) and at this temperature and the associated excess pressure for 24 h with stirring held. The car was then cooled to room temperature, the aqueous dispersion contained therein was removed, the dispersed solid was filtered off and then dried in a drying oven at 80 ° C. The resulting dry powder exhibited scanning electron microscopic examination (SEM) of crystalline particles having a number average grain size diameter of about 8 μm. The chemical analysis of the crystalline particles revealed a Cu / Mo ratio of about 1.

Using Cu-Ka radiation (Siemens Diffrak t-meter D-5000, 40 kV, 30 mA, with automatic di vergence, scattered and counter tube aperture and pel animal detector) showed the crystalline powder CuMoOy the subsequent X-ray diffraction pattern, reproduced in the form of the wavelength used X-ray independent lattice plane distances d [Å], as well as the associated, on the intensity strongest diffraction line related, relative intensity (%) of the different diffraction lines:

there] Intensity% 2.44 100 3.01 58.4 3.14 56.8 2.75 35.5 2.82 30.6 3.39 30.1 1.65 25.2 3.96 21.6 1.72 21.1 2.50 20.5 2.20 17.3 4.68 15.2 2.48 14.5 1.96 13.8 3.71 13.7 3.75 13.2 1.80 12.4 2.90 12.2 2.34 12.1 1.61 11.8 1.59 11.6 3.31 11.5 1.85 11.5 2.04 11.3 2.08 11.2 1.70 11.1 2.00 10.8   1.89 10.7 2.12 10.3 1.88 9.15 1.86 8.52 1.98 8.25 2.30 8.01 2.04 7.29 2.66 6.89 1.57 6.73 1.55 6.54 1.77 6.53 2.37 6.45 1.56 6.03 1.55 5.93 3.45 5.82 2.12 5.79 1.63 5.76 2.06 5.72 1.83 5.43 1.60 5.42 2.14 5.12 5.81 4.91

The inaccuracy of specifying the interplanar spacing d amounts to ± 0.20 Å (the low-intensity Li They probably also include minor offenses cleaning lines).

Starting weight 2:
A finely divided dry mixture of ammonium heptamolybdate tetrahydrate, ammonium metavanadate and ammonium paratungstate heptahydrate, which was based on the following element stoichiometry:
Mo₁₂V _3.46 W _1.38 .

From the initial mass 1 was so much in the output 2, that the molar ratio of the the aforementioned stoichiometric units in the result dry mixture 1.6 (starting material 1) to 0.87 (Starting weight 2) was. Subsequently, the Dry mixture like that in the context of spray drying  at MV1 resulting spray powder to a Schalenkata processed further lysator.

M6: starting mass 1:
The finely divided CuMoOy from M5.

Starting weight 2:
The same mixture as M5, but dissolved in water.

From the initial mass 1 was so much in the output 2, that the molar ratio of the aforementioned stoichiometric units 1.6 (Aus 1) to 0.87 (starting weight 2).

Subsequently, the aqueous mixture was as in MV1 spray dried and to a coated catalyst white further processed. The latter contained the Röntgenbeu transmission pattern of the initial mass 1.

M7: Like M6, however, the starting mass M1 was reduced to one number average grain size = 4 μm.

Again, the resulting shell catalyst contained the B * X-ray diffraction pattern.

M8: Like M6, before the spray-drying of the aqueous mixture, however, copper (II) acetate monohydrate was additionally stirred into it, namely, based on the stoichiometric moiety Mo₁₂V _3.46 W _1.38 of the solute already dissolved in the aqueous mixture, in one stoichiometric frequency of copper of 0.8.

Subsequently, the aqueous mixture was as in MV1 spray dried and to a coated catalyst white which also processed the B * X-ray diffraction pattern contained.

MV2: In 1400 ml of water were dissolved 172.7 g of ammonium molybdate, 43.9 g of ammonium metavanadate and 6.0 g of ammonium dichromate. Separately separated, a second solution of 43.9 g of copper nitrate in 75 ml of water was prepared which had been acidified with 3 ml of concentrated nitric acid. Subsequently, the second solution of the first solution was added dropwise while stirring and heating. At closing, the aqueous mixture was spray-dried as in MV1 and weiterverar processed to form a shell catalyst. The resulting catalytically active material is based on the following stoichiometry:
Mo₁₂V _4.6 Cr _0.56 Cu _2.22 O _x .

M9: starting mass 1:
The finely divided CuMoOy from M5.

Starting weight 2:
Ammonium molybdate, ammonium metavanadate and ammonium dichromate were dissolved in water in the stoichiometric ratio Mo₁₂V _5.6 Cr _0.69 .

From the initial mass 1 was so much in the output 2, that the molar ratio of the aforementioned stoichiometric units 2.22 (Aus 1) to 0.815 (starting weight 2).

Subsequently, the aqueous mixture was as in MV1 spray dried and to a coated catalyst white further processed. The latter contained the Röntgenbeu pattern according to B *.

M10: starting weight 1:
In 500 ml of water were 55.3 g of Cu (II) oxide (CuO, Fa. Merck, Darmstadt, reinst, at least 96%, powdered), 70.1 g of Mo (VI) oxide (MoO₃, Fa. Merck , Darm city, pa, at least 99.5%), 11.4 g of V (V) oxide (V₂O₅, Fa. Merck, Darmstadt, reinst, at least 99%) and 20.9 g of tungstic acid (H₂WO₄, Fa. Merck , Darmstadt, extremely pure, at least 98%).

The resulting aqueous dispersion was equivalent during the preparation of the starting material 1 in M5 be is.

This gave a substantially crystalline powder of stoichiometry Cu₅₀Mo₃₅V₉W₆O _y , which had an X-ray diffraction pattern analogous to the starting material 1 of M5. The number average grain diameter was about 8 microns.

Starting weight 2:
Ammonium molybdate, ammonium metavanadate and Ammoniumpa rawolframat were dissolved in water in a stoichiometric ratio Mo₁₂V₃W _1.11 .

From the initial mass 1 was so much in the output 2, that the molar ratio of the the aforementioned stoichiometric units 0.91 (Aus 2) to 0.032 (starting weight 1).

Subsequently, the aqueous mixture was as in MV1 spray dried and to a coated catalyst white further processed. This also showed the B * Röntgenbeu diffraction pattern.

b) Use of the coated catalysts from a) as catalysts for the gas-phase oxidation of acrolein to acrylic acid

The catalysts were filled into a tubular reactor (V2A Steel, 25 mm inner diameter, 2000 g. Catalyst bed, Salzbadtemperierung) and at reaction temperatures in the range from 250 to 270 ° C using a residence time of 2.0 sec with a gaseous mixture of the composition

5% by volume of acrolein,
7 vol.% Oxygen,
15 vol .-% water vapor and
73% by volume of nitrogen

fed. The salt bath temperature was in all cases like this adjusted, that, after completion of formation, in a simple Passage of a uniform acrolein turnover U of 99% resul oriented. The product gas mixture flowing out of the tube reactor was analyzed by gas chromatography. The results for the Selectivity of acrylic acid formation in application of various The catalysts are shown in the following table.

catalyst S (%) MV1 95.3 M1 95.4 M2 95.4 M3 95.6 M4 95.7 M5 95.5   M6 95.9 M7 96.0 M8 96.0 M10 95.8 MV2 93.4 M9 93.9

Claims (66)

1. Multimetal oxide compositions of the general formula I [A] _p [B] _q (I), in which the variables have the following meanings: A: Mo₁₂ V _a X _b 1 X _c 2 X _d 3 X _e ⁴ X _f ⁵ X _g ⁶ O _x (co-phase), B: X₁₂⁷ Cu _h H _i O _y (key phase), X¹ W, Nb, Ta, Cr and / or Ce,
X 2 Cu, Ni, Co, Fe, Mn and / or Zn,
X³ Sb and / or Bi,
X⁴ Li, Na, K, Rb, Cs and / or H,
X⁵ Mg, Ca, Sr and / or Ba,
X⁶ Si, Al, Ti and / or Zr,
X⁷ Mo, W, V, Nb and / or Ta,
a 1 to 8,
b 0.2 to 5,
c 0 to 23,
d 0 to 50,
e 0 to 2,
f 0 to 5,
g 0 to 50,
h 4 to 30,
i 0 to 20,
x, y are numbers determined by the valency and frequency of elements other than oxygen in I and
p, q non-zero numbers whose ratio p / q is 160: 1 to 1: 1,
which defines the proportion [A] _p in the form of three-dimensionally extended areas A of chemical composition A defined by their local environment because of their chemical composition different from their local surroundings: Mo₁₂ V _a X _b ¹ X _c ² X _d ³ X _e ⁴ X _f ⁵ X _g ⁶ O _x and the proportion [B] _q in the form of three-dimensionally extended areas B of chemical composition B: X₁₂⁷ Cu _h H _i O _y , separated from their local environment by their chemical composition other than their local environment; wherein the regions A, B are distributed relative to each other as in a mixture of finely divided A and finely divided B. 2. Multimetal oxide compositions according to claim 1, with X¹ = W, Nb and / or Cr. 3. Multimetal oxide compositions according to claim 1 or 2, with X² = Cu, Ni, Co and / or Fe. 4. Multimetal oxide according to claim 1 to 3, with X³ = Sb. 5. Multimetal oxide compositions according to claim 1 to 4, with X⁴ = Na and / or K. 6. Multimetal oxide compositions according to claim 1 to 5, with X⁵ = Ca, Sr and / or Ba. 7. Multimetal oxide compositions according to claim 1 to 6, with X⁶ = Si, Al and / or Ti. 8. Multimetal oxide compositions according to claim 1 to 7, with X⁷ = Mo. 9. Multimetal oxide compositions according to claim 1 to 8, with a = 3 to 6. 10. Multimetal oxide compositions according to claim 1 to 9 with b = 0.5 to 2.5. 11. Multimetal oxide compositions according to claim 1 to 10, with c = 0 to 4th   12. Multimetal oxide according to claim 1 to 11, wherein d = 0 to Third 13. Multimetal oxide according to claim 1 to 12, with e = 0 to 0.3. 14. Multimetal oxide according to claim 1 to 13, with f = 0 to Second 15. Multimetal oxide according to claim 1 to 14, with g = 0 to 20th 16. Multimetal oxide compositions according to claim 1 to 15, with h = 6 to 24th 17. Multimetal oxide compositions according to claim 1 to 15, with h = 9 to 17th 18. Multimetal oxide compositions according to claim 1 to 17, with p / q = 20: 1 to 1: 1. 19. Multimetal oxide compositions according to claim 1 to 17, with p / q = 15: 1 to 4: 1. 20. Multimetal oxide compositions according to claim 1 to 19, whose areas A have a composition according to the following general formula II Mo₁₂ V _a 'X _b ¹'X _c ²'X _f ⁵'X _g ⁶'O _x' (II) with
X¹ W and / or Nb,
X² Cu and / or Ni,
X⁵ Ca and / or Sr,
X⁶ Si and / or Al,
a '3 to 6,
b '1 to 2,
c '1 to 3,
f '0 to 0.75,
g '0 to 10 and
x 'is a number determined by the valence and frequency of the elements other than oxygen in II. 21. Multimetal oxide compositions according to claim 1 to 20, which contain the proportion [B] _q in the form of three-dimensionally extended areas of chemical composition B whose maximum diameter d _B <0 to 300 microns. 22. Multimetal oxide compositions according to claim 1 to 21, which contain the proportion [B] _q in the form of three-dimensionally extended areas of chemical composition B whose maximum diameter d _{B is} 0.1 to 200 microns. 23. Multimetal oxide compositions according to claim 1 to 22, which contain the proportion of [B] _q in the form of three-dimensionally extended areas of the chemical composition B, whose Größtdurchmes d _B 0.5 to 50 microns. 24. Multimetal oxide compositions according to claim 1 to 23, which contain the proportion [B] _q in the form of three-dimensionally extended areas of chemical composition B whose maximum diameter d _{B is} 1 to 30 microns. 25. Multimetal oxide compositions according to claim 1 to 24, the preparation of which B contain crystallites having the X-ray diffraction pattern of at least one of the following Kupfermolybdate (the expression in brackets shows the source of the associated X-ray diffraction fingerprint):
Cu₃ (MoO₄) ₂ (OH) ₂ (Lindgrenit, tab 36-405 of the JCPDS-ICDD file 1991)),
Cu₄ Mo₆ O₂₀ (A. Moini et al., Inorg. Chem. 25 (21) (1986) p. 3782 to 3785)
Cu₄ Mo₅ O₁₇ (tab 39-181 of the JCPDS-ICDD file (1991)),
Cu₆ Mo₅ O₁₈ (file 40-865 of the JCPDS-ICDD file (1991)),
Cu₆ Mo₄ O₁₅ (tab 35-17 of the JCPDS-ICDD file (1991)),
Cu Mo O₄ (tab 22-242 of the JCPDS-ICDD file (1991)),
Cu _4-x Mo₃ O₁₂ with x = 0 to 0.25 (tabs 24-56 and 26-547 of the JCPDS-ICDD file (1991)),
Cu₃ Mo₂ O₉ (tabs 24-55 and 22-609 of the JCPDS-ICDD file (1991)),
Cu₂Mo O₅ (tab 22-607 of the JCPDS-ICDD file (1991)). 26. Multimetal oxide compositions according to claim 1 to 25, whose preparation che B crystallites B * of oxometallates of the general For mel III Cu Mo _A W _B V _C Nb _D Ta _E O _y · (H₂O) _F (III), with
1 / (A + B + C + D + E) 0.7 to 1.3,
F 0 to 1,
B + C + D + E 0 to 1 and
Y is a number which is determined by the valence and frequency of the elements other than oxygen in III,
a structure type containing the following Röntgenbeu transmission pattern, reproduced in the form of independent of the wavelength of the X-ray radiation used, the most characteristic diffraction lines deriving, Netzebenenab stände d ± 0.20 [Å], comprising:
3:14; 3.01; 2.44; 2.82; 2.75; 3.39; 1.72; 1.65; 2.50; 3.96; 1.80; 1.59; 2.48; 1.61; 1.70; 1.89; 2.20; 1.86; 2.90; 1.96; 2.08; 2.34; 4.68; 2:12; 1.98; 2.00; 1.88; 2.04; 3.71; 3.75; 2.30; 2.37; 3.31. 27. Multimetal oxide compositions according to claim 26, with 1 / (A + B + C + D + E) = 0.85 to 1.15. 28. Multimetal oxide compositions according to claim 26, with 1 / (A + B + C + D + E) = 0.95 to 1.05. 29. Multimetal oxide compositions according to claim 26, with 1 / (A + B + C + D + E) = 1. 30. Multimetal oxide compositions according to claim 26 to 29, with F = 0.   31. Multimetal oxide compositions according to claim 26 to 30, with B + C + D + E = 0 to 0.5. 32. Multimetal oxide compositions according to claim 31, with B + C + D + E = 0 to 0.1. 33. Multimetal oxide compositions according to claim 31, with B + C + D + E = 0. 34. Multimetal oxide according to claim 26 to 33, in which the proportion of crystallites B *, based on the total mass of the proportion [B] _q , at least 25 wt .-% is. 35. Multimetal oxide materials according to claim 26 to 33, in which the proportion of crystallites B *, based on the total mass of the proportion [B] _q , at least 50 wt .-% is. 36. Multimetal oxide according to claim 26 to 33, in which the proportion of crystallites B *, based on the total mass of the proportion [B] _q , at least 75 wt .-% is. 37. Multimetal oxide according to claim 26 to 33, in which the proportion of crystallites B *, based on the total mass of the proportion [B] _q , at least 90 wt .-% is. 38. Multimetal oxide compositions according to claim 26 to 33, in which the proportion of the crystallites B *, based on the total mass of the fraction [B] _q , 95 to 100 wt .-% is. 39. Multimetal oxide according to claim 26 and claim 34 to 38, whose crystallites B * the stoichiometry IV Cu Mo _A O _y · (H₂O) _F (IV), with
1 / A 0.7 to 1.3,
F0 to 1 and
Y is a number determined by the valence and frequency of the elements other than oxygen in IV,
respectively. 40. Multimetal oxide compositions according to claim 39 with 1 / A = 0.85 to 1.15. 41. Multimetal oxide compositions according to claim 39 with 1 / A = 0.95 to 1.05. 42. Multimetal oxide compositions according to claim 39, with 1 / A = 1. 43. Multimetal oxide according to claim 39 to 42, where F = 0. 44. Multimetal oxide of the general formula III CuMo _A W _B V _C Nb _D Ta _E O _y · (H₂O) _F (III), with
1 / (A + B + C + D + E) 0.7 to 1.3,
F 0 to 1,
B + C + D + E 0 to 1 and
Y is a number which is determined by the valence and frequency of the elements other than oxygen in III,
the structural type of which is the subsequent X-ray diffraction pattern, represented in the form of wavelengths independent of the wavelength of the x-ray radiation used, which are based on the most characteristic diffraction lines, d ± 0.20 [Å],
3:14; 3.01; 2.44; 2.82; 2.75; 3.39; 1.72; 1.65; 2.50; 3.96; 1.80; 1.59; 2.48; 1.61; 1.70; 1.89; 2.20; 1.86; 2.90; 1.96; 2.08; 2.34; 4.68; 2:12; 1.98; 2.00; 1.88; 2.04; 3.71; 3.75; 2.30; 2.37; 3.31. 45. Multimetal oxide compositions according to claim 44, with 1 / (A + B + C + D + E) = 0.85 to 1.15. 46. Multimetal oxide compositions according to claim 44, with 1 / (A + B + C + D + E) = 0.95 to 1.05. 47. Multimetal oxide compositions according to claim 44, with 1 / (A + B + C + D + E) = 1. 48. Multimetal oxide compositions according to claim 44 to 47, where F = 0.   49. Multimetal oxide compositions according to claim 44 to 48, with B + C + D + E = 0 to 0.5. 50. Multimetal oxide compositions according to claim 44 to 48, with B + C + D + E = 0 to 0.1. 51. Multimetal oxide compositions according to claim 44 to 48, with B + C + D + C = 0. 52. Multimetal oxide compositions according to claim 44, the stoichiome trie IV CuMo _A O _y · (H₂O) _F (IV), with
1 / A 0.7 to 1.3,
F0 to 1 and
Y is a number which is determined by the valency and frequency of the elements other than oxygen in IV,
respectively. 53. Multimetal oxide compositions according to claim 52, with 1 / A = 0.85 to 1.15. 54. Multimetal oxide compositions according to claim 52, with 1 / A = 0.95 to 1.05. 55. Multimetal oxide compositions according to claim 52 with 1 / A = 1. 56. Multimetal oxide compositions according to claim 52 to 55, where F = 0. 57. Process for the preparation of multimetal oxide materials according to An Speech 44 to 56, characterized in that sources the elements constituting the multimetal oxide materials intimately mixes each other and the resulting intimate mixture in an overpressure vessel in the presence of under superatmospheric Pressurized steam at temperatures in the range of <100 to 600 ° C thermally treated. 58. The method according to claim 57, characterized in that the hydrothermal treatment takes place under such conditions, under which water vapor and liquid water coexist assets.   59. The method according to claim 57 or 58, characterized that the coexisting liquid aqueous phase the total amount the starting mixture in suspension and / or solution on zuneh men can. 60. The method according to claim 57 to 59, characterized that as sources exclusively oxides and / or hydroxides starts. 61. The method according to claim 57 to 60, characterized that the stoichiometric composition of elementary con substituents in the starting mixture of those of the general For mel (III) corresponds to claim 44. 62. Multimetal oxide compositions obtainable by a process according to Claim 61. 63. Multimetal oxide, obtainable by dissolving in 500 ml of water 55.3 g of Cu (II) oxide and 100 g of Mo (VI) oxide are dispersed, the Total amount of the resulting aqueous dispersion in one 2.5 l autoclave heated to 350 ° C and at this temperature left under stirring for 24 h, then room temp cools the aqueous dispersion, the therein filtered-off solid and dried at 80 ° C. 64. Use of multimetal oxide compositions according to claims 44 to 56 and claims 62 to 63 for the production of multimetal Mass according to claim 1 to 24. 65. A process for the preparation of Multimetalloxidmassen according to claim 1, characterized in that a Oxometallat B: X₁₂⁷ Cu _h H _i O _y in finely divided form prefers (starting material 1) and then the starting material 1 with suitable sources of the elemental constituents of an oxometalate AA: Mo₁₂ V _a X _b X X _c ² X _d ³ X _e ⁴ X _f ⁵ X _g ⁶ O _x brings in intimate contact in the desired ratio and a resulting dry mixture at a temperature of 250 to 450 ° C calcined. 66. Use of multimetal oxide compositions according to Claims 1 to 43 as catalysts for gas-phase catalytically oxidative Her position of acrylic acid from acrolein.