DE102009017443A1 - Partial oxidation of an alkylaromatic compound e.g. toluene and o-xylol, in the gas phase under the use of catalyst, whose catalytically active mass contains a multimetal oxide compound - Google Patents

Abstract

Partial oxidation of an alkylaromatic compound in the gas phase under the use of catalyst, whose catalytically active mass contains a multimetal oxide compound (I), is claimed. Partial oxidation of an alkylaromatic compound in the gas phase under the use of catalyst, whose catalytically active mass contains a multimetal oxide compound of formula (Cu aMo bM cO d.eH 2O) (I), is claimed. M : at least one element comprising Ti, Zr, V, Nb, Ta, Cr, W, Re, Mn, Fe, Co, Ni, Ag, Zn, Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, B, Al, Ga, Si, Sn, Pb, P, Sb, Bi, La or Ce; a/b : 0.1-10; c : less than 0.1, where a+b+c is 1; d : number that is determined by the valency and frequency of the various elements of oxygen; and e : 0-20. An independent claim is included for the gas-phase oxidation catalyst comprising catalytically active mass.

Description

The The invention relates to a process and catalysts for partial oxidation of alkylaromatics in the gas phase, in particular for selective oxidation of alkyl aromatics to aromatic alcohols, aldehydes, carboxylic acids and / or carboxylic anhydrides.

carboxylic acids and / or carboxylic anhydrides, such as phthalic anhydride, are technically largely by catalytic gas phase oxidation of alkylaromatics, such as o-xylene, in fixed bed reactors. For this purpose, a mixture of an oxygen-containing gas, for example Air, and the alkyl aromatic to be oxidized at elevated Temperature passed through a bed of catalyst.

This selective oxidation of alkylaromatics presumably proceeds by a combined parallel and subsequent step mechanism. The starting material, such as o-xylene, is on the catalyst surface consecutively via intermediate oxidation products to the final product, for. As phthalic anhydride, oxidized. At each stage, the intermediate oxidation product can either be further oxidized or desorbed from the catalytically active surface. In a concurrent parallel reaction, a total oxidation takes place, which starts either directly from the starting material or from an intermediate of the selective route. In the selective oxidation of o-xylene to phthalic anhydride 12 bonds must be broken and formed again. Among other things, the abstraction of six hydrogen and the insertion of three oxygen atoms. In addition to phthalic anhydride, many additional reaction products are formed. These can be essentially divided into two subgroups. The molecules o-tolualdehyde, o-toluic acid and phthalide have a lower C / O atomic ratio than phthalic anhydride. These suboxidation products have eight C atoms, such as phthalic anhydride. They are the C ₈ intermediates of the gas phase oxidation and can be converted into the target product phthalic anhydride. The second group includes the over-oxidation products maleic anhydride and the carbon oxides CO and CO ₂ (often summarized as CO _x ). Furthermore, in the o-xylene oxidation, the following by-products may be formed in a lower concentration: benzaldehyde, p-benzoquinone, benzoic acid, benzene, dimethylmaleic anhydride, methylbenzyl alcohol, methylmaleic anhydride, phthalan, o-phthaldehyde and toluene.

Already low yield increases of industrial production processes lead to significant economic benefits. It is desirable to have catalysts, those with high selectivity to the desired end product and / or its suboxidation products. The underoxidation products can be desired by known methods End product to be further oxidized.

The EP 0256352 describes a two-stage process for the preparation of phthalic anhydride, wherein in a first stage o-xylene is oxidized in the liquid phase to o-toluic acid and the isolated o-toluic acid is further oxidized in a second step on a conventional catalyst in the gas phase. It is claimed that higher yields and / or purities can be achieved with the two-stage process than with pure gas phase oxidation.

The WO 00/27753 describes a process for the production of phthalic anhydride by partial oxidation of o-xylene in the gas phase with a molecular oxygen-containing gas, wherein a shell catalyst whose catalytically active material contains a silver vanadium oxide bronze, in combination with a catalyst which in its catalytically active material as essential catalytically active ingredients vanadium pentoxide and anatase contains used.

The EP 0 756 894 describes multimetal oxide compositions containing a molybdenum, vanadium and at least one active phase comprising tungsten, niobium, tautal, chromium and cerium and a promoter phase comprising copper and at least one of the elements molybdenum, tungsten, vanadium, niobium and tantalum. Active phase and promoter phase are relative to each other as in a mixture of finely divided active and promoter phase. The multimetal oxide materials are z. B. used as catalysts for the oxidation of acrolein to acrylic acid.

The NL 7209921 describes a gas phase oxidation of toluene to benzaldehyde at 200-600 ° C on a catalyst comprising molybdenum and another element M (M = Fe, Ni, Co, Sb, Bi, V, P, Sm, Ta, Sm, Cr) in the Ratio M / Mo <1 contains.

The US 4,140,722 describes a gas phase oxidation of substituted p-xylenes to substituted terephthalaldehydes on a catalyst containing W, Mo and Bi.

The US 5,324,702 describes a gas phase oxidation of o-xylene to Fe ₂ (MoO ₄ ) ₃ at 400-600 ° C to a mixture of o-tolualdehyde, phthalic anhydride and phthalide.

Of the Invention is based on the object, new multimetal oxides as Catalysts for the partial oxidation of alkylaromatics to find that with high selectivity to aromatic Alcohols, aldehydes, carboxylic acids and / or carboxylic anhydrides to lead.

The object is achieved by processes for the partial oxidation of alkylaromatics in the gas phase using a catalyst whose catalytically active composition contains a multimetal oxide of the general formula I. Cu _a Mo _b M _c O _d · eH ₂ O (I) wherein
M is at least one of Ti, Zr, V, Nb, Ta, Cr, W, Re, Mn, Fe, Co, Ni, Ag, Zn, Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba , B, Al, Ga, Si, Sn, Pb, P, Sb, Bi, La, Ce, selected element,
a / b has a value of 0.1 to 10,
c has a value of less than 0.1,
a + b + c has the value 1,
d is a number which is determined by the valence and frequency of the elements other than oxygen in formula I,
e has a value from 0 to 20.

The The invention also relates to a gas phase oxidation catalyst with a catalytically active mass consisting essentially of a Metal mixed oxide of the general formula I consists.

The catalysts of the invention are based on Kupfermolybdaten. By incorporation of atoms M in the copper molybdate structure can the catalytic properties of the multimetal oxide modified its activity and selectivity become.

In of the formula I, a / b preferably has a value of 0.2 to 5, in particular from 0.33 to 3, more preferably from 1.0 to 1.5.

In of formula I, c preferably has a value of 0.0001 to 0.05.

In of formula I is preferably M for at least one V, Nb, Cr, Re, Fe, Co, Ag, Zn, B, Al, Ga, Pb, P, Sb, Bi, La, Ce selected element.

The multimetal oxides preferably comprise crystallites or consist essentially of crystallites which have the structural type of one or more of the copper molybdates listed below: Cu ₄ Mo ₆ O ₂₀ (File card 01-078-0380 of the ICDD PDF-2 file (release 2006)), Cu ₄ Mo ₅ O ₁₇ (File card 01-084-1106 of the ICDD PDF-2 file (release 2006)), Cu ₆ Mo ₅ O ₁₈ (File card 01-084-0842 of the ICDD PDF-2 file (release 2006)), CuMoO ₄ Medium-pressure modification (index card 01-085-1530 of the ICDD PDF-2 file (release 2006)), CuMoO ₄ High pressure modification (index card 01-077-0699 of the ICDD PDF-2 file (release 2006)), Cu _3.85 Mo ₃ O ₁₂ (File card 01-070-2494 of the ICDD PDF-2 file (release 2006)), Cu ₃ Mo ₂ O ₉ (File cards 01-087-0455 or 00-024-0055 of the ICDD PDF-2 file (release 2006)), Cu _1.49 Mo ₈ O ₂₄ (File card 01-082-0843 of the ICDD PDF-2 file (release 2006)).

The location for the associated X-ray diffraction fingerprint is indicated in brackets. The presence of crystallites of one of the structural types mentioned can be determined from an X-ray powder diffractogram of the multimetal oxide. If the characteristic and most intense diffraction lines in the diffractogram (eg given as lattice plane spacings d [Å]) coincide with those of the X-ray diffraction fingerprint, the multimetal oxide has the respective structure type. There is more than one kris talline phase, the characteristic diffraction patterns in the diffractogram can usually be assigned to the underlying structure types.

The multimetal oxide may be present as a single phase or a mixture of crystalline and / or amorphous phases of the compositions of Cu _w Mo _x M _y O _z, Cu _w Mo _x O _z Cu _w M _y O _z, Mo _x M _y O _z Cu, _w O _z , Mo _x O _z and / or M _y O _z include, wherein w, x, y, z are each independently selected so that the sum composition of the mixture of formula I corresponds.

• (i) Umsetzung wenigstens einer Molybdänquelle, einer Kupferquelle und gegebenenfalls einer Quelle des Elements M;
• (ii) Behandeln eines Multimetalloxids der Formel Cu_aMo_bO_d·eH₂O (worin a + b = 1 und d und e die oben angegebene Bedeutung haben) mit einer Quelle des Elements M;
• (iii) Behandeln eines Multimetalloxids der Formel Cu_aMo_bM¹ _cO_d·eH₂O mit einer Quelle des Elements M² (worin a, b, c, d, e die oben angegebene Bedeutung haben; und M¹ und M² gleich oder verschieden sind und die oben für M angegebene Bedeutung haben).

The multimetal oxide compositions according to the invention can be obtained in various ways. You can z. B. be prepared by one of the following methods:

• (i) reacting at least one molybdenum source, a copper source and optionally a source of the element M;
• (ii) treating a multimetal oxide of the formula Cu _a Mo _b O _d · eH ₂ O (wherein a + b = 1 and d and e are as defined above) with a source of the element M;
• (iii) treating a multimetal oxide of the formula Cu _a Mo _b M ¹ _c O _d · eH ₂ O with a source of the element M ² (in which a, b, c, d, e have the abovementioned meaning and M ¹ and M ^{2 are the} same or different and have the meaning given above for M).

In usually includes a thermal treatment a temperature of at least 200 ° C.

to Production of the metal mixed oxide according to (i) is generally a molybdenum source, a copper source and optionally a source of the element M intimately mixed. The blending can be done dry, but preferably in a solution and / or suspension in a solvent. As a solvent can polar organic solvents, such as alcohols, Polyols, polyethers or amines, e.g. As pyridine serve, preferably is used as solvent water.

When Molybdenum source, copper source and source of element M Oxides or compounds of the elements are used in the Heating, at least when warming in presence from oxygen to oxides are convertible. For this include hydroxides, oxide hydroxides, polyoxometalates, carboxylates, Carbonates, and in particular nitrates.

Examples of suitable molybdenum sources are Mo powder, ammonium molybdate or ammonium polymolybdate (eg ammonium dimolybdate, ammonium heptamolybdate, ammonium octamolybdate, ammonium decamolybdate), molybdenum oxides, such as MoO ₃ , MoO ₂ , molybdenum halides, molybdenum oxyhalides and molybdenum organyls. Because of its general availability and good solubility, ammonium heptamolybdate is preferably used.

Suitable sources of the element copper are, for example, Cu powders, copper oxides (such as Cu ₂ O, CuO), copper hydroxides, copper nitrate, copper acetate, copper oxalate, copper chloride, copper sulfate and copper organyls. Preferably, copper nitrate or copper acetate are used.

When Source of the element M are usually chosen such compounds, which are soluble in the solvent used. It may, for example, the carboxylates, in particular the acetates or oxalates, nitrates, oxides, carbonates or halides be used. Elemental acids or their ammonium salts can be used if M z. B. stands for P. Formulations of nanoparticles of oxides or hydroxides of Elements M can also be used. Farther polyanions such as heteropolyacids from Anderson, Dawson or Keggin type as sources for the elements M be used.

ever according to the desired chemical composition of the multimetal of the formula I are for the production of which consist of a, b and c of formula I resulting amounts of molybdenum source, copper source and source of element M mixed.

The blending of the molybdenum source, copper source and source of the element M can generally be carried out at room temperature or at elevated temperature. In general, the reaction is carried out at temperatures of 20 to 375 ° C, preferably at 20 to 100 ° C and particularly preferably at 60 to 100 ° C. If the temperature of the reaction is above the temperature of the boiling point of the solvent used, the reaction is expediently carried out under the autogenous pressure of the reaction system in a pressure vessel. Preferably, the reaction conditions are chosen so that the reaction can be carried out at atmospheric pressure. The duration of this reaction, depending on the nature of the reacted starting materials and the temperature conditions applied a few Mi be up to several days.

The thus formed mixture can be isolated from the reaction mixture and be stored until further use. The insulation can z. B. by removing the solvent and drying the obtained solid. For drying are usual Dryers, such as drum dryers, or freeze dryers. Especially advantageous is the drying of the resulting solution and / or suspension carried out by spray drying. The spray drying is generally below atmospheric or reduced Pressure made. Depending on the pressure applied and the solvent used the inlet temperature of the drying gas is determined. In general Air is used as the drying gas, but it can of course be used Other drying gases such as nitrogen or argon can be used. The inlet temperature of the drying gas in the spray dryer is advantageously chosen so that the starting temperature of cooled by evaporation of the solvent Drying gas 200 ° C for a longer time Period does not exceed. In general, the starting temperature of the drying gas at 50 to 150 ° C, preferably 100 set to 140 ° C.

The Source of the element M, for example, also one to be sprayed or solution of the molybdenum and copper source to be dried be added.

The Drying usually gives an amorphous product. Conveniently, one can compact the product and make it suitable in a fraction Grain size, z. B. between 500-1000 microns, classified.

In the preparation according to process (ii), a multimetal oxide of the formula Cu _a Mo _b O _d · eH ₂ O _is treated with a source of element M, preferably by impregnation with a solution of the source of element M in an aqueous or nonaqueous solvent , The impregnation can also be carried out under hydrothermal conditions. Thermal or hydrothermal post-treatment is also possible. The preparation according to process (iii) takes place in an analogous manner.

Optional can treat the multimetal oxide composition with a source of Elements M also after the application described below Carrier body done.

typically, includes a thermal treatment, preferably below controlled atmosphere. Such a thermal treatment takes place statically or preferably moves under rotating movements of the Furnace chamber. Typical temperature regime for the thermal Treatment are in the range of 200 to 800 ° C, preferably from 250 to 500 ° C, more preferably from 300 to 400 ° C. The thermal treatment can be carried out under inert (for example nitrogen or noble gases), oxidizing (for example oxygen) or varying Atmosphere (first oxidizing then reducing Atmosphere). The person skilled in the art is aware that also mixtures of the gases mentioned can be used. The term oxidizing means that in the supplied Gas stream after conversion of all contained oxidizing and reducing agents, Oxidant remains in the gas stream, so gross an oxidizing Gas stream is supplied. The name means reducing that in the supplied gas stream after reaction all contained oxidizing and reducing agents, reducing agents remains in the gas stream, so fed to a reducing gas stream gross becomes. Inert means in this context that either no Oxidizing agent or reducing agent are supplied, or oxidizing and reducing agent in the supplied gas stream gross are inert, that is, that in the supplied gas stream after conversion of all contained oxidizing and reducing agents, neither oxidant nor reducing agent remains in the gas stream.

It may be thermally treated in a stagnant or flowing atmosphere, preferably a treatment is carried out under a flowing gas stream, with a constant supply of fresh gas prior to a gas recycle being preferred. The composition of the atmosphere can be varied as a function of the calcination temperature and duration. Typically, agitated thermal treatment, for example by, for example, rotary calcining drums, shaking or fluidization, is preferred. For the production in the laboratory furnaces are like in the 1 of the DE-A-10122027 prefers.

The Thermal treatment can also be done under temperature conditions the gas phase oxidation in the gas phase oxidation reactor take place. In In this case, a so-called pre-catalyst in the Reactor introduced under the temperature conditions of the gas phase oxidation converted into a catalyst according to the invention becomes.

Also included within the scope of the invention is the washing of the multimetal oxide composition (see JP-A 8-57319 or EP-A 1254707 ) with suitable liquids. In particular, aqueous solutions of anor ganic or organic acids, as well as alcoholic solutions (with and without acids) and aqueous hydrogen peroxide solutions are examples of suitable solvents. Typically, in such a washing process, the phase heterogeneity is reduced and foreign phases (eg the so-called k-phase) are washed out.

The Multimetal oxide may be in the form of a full catalyst or preferably in the form of a shell catalyst for the partial oxidation be used in the gas phase.

To modify the mechanical properties of the multimetal oxide composition finely divided, z. As nanoscale, oxides such as TiO ₂ , SiO ₂ , ZrO ₂ , are added.

to Production of a full catalyst is the powdered Multimetal oxide composition z. B. by z. B. by tableting, extruding or extruding to the desired catalyst geometry compacted. For Vollkatalysatorherstellung can next the powdered mixed metal oxide mass optionally Aids such. As graphite or stearic acid as a lubricant and / or molding aids and reinforcing agents such as microfibers made of glass, asbestos, silicon carbide or potassium titanate become.

to Preparation of coated catalyst becomes the powdered Multimetal oxide composition on preformed inert catalyst supports applied suitable geometry.

Virtually all support materials of the prior art, which are advantageously used in the production of coated catalysts, can be used as the inert support material, for example quartz (SiO ₂ ), porcelain, magnesium oxide, tin dioxide, silicon carbide, rutile, alumina (Al ₂ O ₃ ). , Aluminum silicate, steatite (magnesium silicate), zirconium silicate, cersilicate or mixtures of these support materials. Particularly advantageous support materials are steatite and silicon carbide.

The Support material is usually non-porous. Of the Expression "non-porous" is in the sense of from "to technically ineffective amounts of pores non-porous" to understand, because technically inevitable a small number of pores in the carrier material which ideally contains no pores should be able to exist.

The Form of the carrier material is for the invention Shell catalysts generally not critical. For example may be catalyst supports in the form of spheres, rings, Tablets, spirals, tubes, extrudates or grit become. The dimensions of these catalyst supports correspond usually for the production of coated catalysts for the gas phase partial oxidation of aromatic hydrocarbons used catalyst supports.

to cup-shaped coating of the inert carrier material known methods are used. For example, a suspension the active mass or a precursor in a heated Coating drum at elevated temperature on the catalyst carrier be sprayed on. Instead of drag drums can Also be used fluid bed coater.

The Suspension medium is generally water, preferably binder such as higher alcohols, polyhydric alcohols, eg. For example, ethylene glycol, 1,4-butanediol or glycerol, dimethylformamide, dimethylacetamide, Dimethylsulfoxide, N-methylpyrrolidone or cyclic ureas, such as N, N'-dimethylethyleneurea or N, N'-dimethylpropyleneurea, or (co) polymers, dissolved or advantageously in the form of a aqueous dispersion are added, in general Binder contents of 10 to 20 wt .-%, based on the solids content the suspension are suitable. Suitable polymeric binders are z. Vinyl acetate / vinyl laurate, vinyl acetate / acrylate, styrene / acrylate, Vinyl acetate / maleate or vinyl acetate / ethylene copolymers. At a thermal treatment at temperatures above 200 to 500 ° C. the binder escapes through thermal decomposition and / or combustion from the applied layer.

The Layer thickness of the catalyst shell or the sum of the layer thicknesses the shells; containing the catalytically active ingredients, is generally 10 to 250 microns.

The catalysts of the invention are for the partial oxidation of alkylaromatics to aromatic alcohols, Aldehydes, carboxylic acids and / or carboxylic anhydrides used.

The alkylaromatic used is a compound having at least one carbocyclic or heterocyclic aromatic ring structure which can be reacted under the conditions of gas phase partial oxidation to aldehydes, carboxylic acids and / or carboxylic acid anhydrides. In particular, a or polyalkylated aromatics, in particular methylated and / or ethylated aromatics.

The aromatic parent compounds can carry substituents, which are inert under the conditions of partial oxidation, So z. As halogen or the trifluoromethyl, nitro, amino or Cyano group. Non-inert substituents may also be considered when desired in partial oxidation conditions Substituents, such as the aminomethyl or the hydroxymethyl group.

preferred aromatic hydrocarbons are toluene, o-xylene, m-xylene, p-xylene as well as methylpyridines.

A Embodiment of the invention Method relates to the preparation of o-tolualdehyde from o-xylene.

A Embodiment of the invention Method relates to the preparation of m-tolualdehyde from m-xylene.

A Embodiment of the invention Partial oxidation process involves the preparation of phthalic anhydride from o-xylene. The novel catalysts can for this purpose in combination with other, differently active Catalysts, for example, catalysts of the prior art vanadium oxide / anatase-based.

Further Embodiments of the invention Partial oxidation process involves the production of benzoic acid and / or benzaldehyde from toluene, or from pyridinecarboxylic acids, such as nicotinic acid, from methylpyridines such as β-picoline.

The catalysts of the invention can alone or in combination with others, different active Catalysts, for example, catalysts of the prior art vanadium oxide / anatase-based. The different ones Catalysts are generally carried in separate catalyst beds, which may be arranged in one or more fixed catalyst beds can, arranged in the reactor.

The catalysts or precatalysts according to the invention are suitably in the reaction tubes a tubular reactor filled from the outside, z. B. by means of a molten salt, thermostated to the reaction temperature become. About the thus prepared catalyst bed the reaction gas is at temperatures of generally 250 to 450 ° C, preferably 300 to 420 ° C and especially preferably from 320 to 400 ° C and at an overpressure from generally 0.1 to 2.5 bar, preferably from 0.3 to 1.5 bar with a space velocity of generally 750 to 10,000 h-1, preferably from 1500 to 4000 passed.

The The reaction gas supplied to the catalyst generally becomes by mixing a molecular oxygen-containing gas, that, in addition to oxygen, suitable reaction moderators and / or Diluents, such as water vapor, carbon dioxide and / or Nitrogen, may contain, with the oxidized alkylaromatic generated. The molecular oxygen-containing gas contains generally 1 to 100% by volume, preferably 2 to 50% by volume and particularly preferably 4 to 30% by volume of oxygen, 0 to 30% by volume, preferably 0 to 20% by volume of water vapor and 0 to 50% by volume, preferably 0 to 1 vol .-% carbon dioxide, balance nitrogen. Especially advantageous For example, air is used as the molecular oxygen-containing gas.

at a preferred embodiment of the invention Method sets the alkyl aromatic on a catalyst whose catalytically active composition contains a multimetal oxide of the formula I, to an intermediate reaction mixture and sets the intermediate reaction mixture or fractions thereof on one at least one further catalyst around.

• a) den nicht umgesetzten Alkylaromat vom gewünschten Oxidationsprodukt und seinen Unteroxidationsprodukten abtrennt und zurückführt und den Strom aus gewünschtem Oxidationsprodukt und seinen Unteroxidationsprodukten einer oder mehreren weiteren Katalysatorschüttungen zuführt, wo die Unteroxidationsprodukte selektiv zum gewünschten Oxidationsprodukt oxidiert werden; oder
• b) das Produktgemisch ohne weitere Aufarbeitung über eine zweite und gegebenenfalls weitere Katalysatorschüttungen leitet.

For this purpose, for example, the alkylaromatic is first reacted on a bed of the catalyst according to the invention with partial conversion to give a product mixture which may contain the desired oxidation product, suboxidation products thereof and unreacted alkylaromatic. The product mixture can then be further processed by alternatively

• a) separating and recycling the unreacted alkylaromatic from the desired oxidation product and its suboxidation products and feeding the stream of the desired oxidation product and its suboxidation products to one or more further catalyst beds where the suboxidation products are selectively oxidized to the desired oxidation product; or
• b) passes the product mixture over a second and optionally further catalyst beds without further work-up.

A Such reaction procedure proves to be particularly advantageous for the production of phthalic anhydride o-xylene. Through this type of reaction is total a significantly higher phthalic anhydride yield achieved as with catalysts of the prior art alone since the inventive shell catalysts, o-xylene essential more selective to phthalic anhydride or its suboxidation products can oxidize than this with the sole use of Vanadium oxide / anatase-based catalyst systems according to prior art the technology is possible.

The Invention is further illustrated by the following examples.

Preliminary remarks

All X-ray diffractograms were taken with a diffractometer of the manufacturer Bruker AXS GmbH, 76187 Karlsruhe Device name: D8 Discover with GADDS (General Area Detector Diffraction System). Cu-Ka radiation was used to record the diffractograms.

Calcinations were made in a rotary ball furnace after the DE-A 10122027 carried out (the rotation speed was 15 / min).

The catalytic testing was carried out on 1 ml or 1/3 ml of the sample in a 48-fold test reactor according to DE 198 09 477.9 ,

GHSV (gas hourly space velocity) is the gas volume / catalyst volume per hour. The composition of the gas stream is determined by the concentration to o-xylene, oxygen and water vapor defined. The difference to 100 vol.% was nitrogen. The analysis of the product gas flow was carried out by a gas chromatographic analysis (GC 6890, Fa. Agilent).

Example 1:

The example describes the preparation of the multimetal oxides A-H of the general composition Cu _a Mo _b M _c O _d · eH ₂ O with c = 0 in various synthetic and calcination variants.

Example A

Synthesis of a freeze-dried precursor for the preparation of multimetal oxides having the composition Cu _0.5 Mo _0.5 O ₂ :

you put aqueous ammonium heptamolybdate solution (1010 ml; 0.15 mol / l; 1.06 mol Mo) in a 2 l beaker and dripped with vigorous stirring, aqueous copper nitrate solution (265 ml, 4 mol / l, 1.06 mol of Cu) through a 1-liter dropping funnel slowly too. The dripping rate was between 50-60 Drops per minute. After complete addition stirred reflux the mixture for an additional 12 hours. The solution was slowly added using a 1 ml pipette a dewar with liquid nitrogen enlisted, using a magnetic stir bar touched. The frozen pellets were placed on metal dishes of 15 cm diameter (maximum bed height 0.5 cm) and in a freeze-drying plant of the company Christ at -30 ° C. heated. The main drying took place over several Stages. First, a drying at -25 ° C and 2.565 bar over 24 h, followed by drying over 24 h at -10 ° C and 2.565 bar and subsequent heating at 0 ° C.

To the removal of the pellets from the freeze-drying were these in Petri dishes at 80 ° C in a drying oven after-dried in air for 12 h.

The dried pellets were prepared by means of a compact (Powtec) compacted, to a fraction between 500 and 1000 microns classified.

Example Al

Synthesis of a multimetal oxide with the composition Cu _0.5 Mo _0.5 O ₂ (variant with calcination under air / nitrogen):

The precursor from Example A was calcined in a rotary kiln as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of air was adjusted to provide a 10-fold volume exchange per hour. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 250 ° C was 2 hours. This was followed by switching to inert conditions (nitrogen) at a 10-fold volume exchange per hour. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a Cu molybdate with the CuMoO ₄ structure (medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) was detected.

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 2000 1 7 5 15,851 8113 51182 330 1500 1 7 5 25074 7873 31399 330 2000 1 7 10 19088 7717 40429 330 2000 1 13 5 14653 6992 47719 330 2000 1 7 20 22723 6728 29608 330 2000 1 7 0 20224 5946 29340 330 2500 1 7 5 16564 5245 31667 310 2000 1 7 5 12259 3679 30013 310 2000 1 7 0 15806 3332 21079 290 2000 1 7 10 13106 2362 18018

Example A2

Synthesis of a multimetal oxide with the composition Cu _0.5 Mo _0.5 O ₂ (variant with calcination under air):

The precursor from Example A was calcined in a rotary kiln as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of air was adjusted to provide a 10-fold volume exchange per hour. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 250 ° C was 2 hours. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a Cu molybdate with the CuMoO ₄ structure (medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) was detected.

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 1500 1 7 5 17887 8571 47918 330 2000 1 7 5 18004 7814 43403 330 2000 1 7 10 19039 7746 40686 330 2000 1 7 20 18059 7242 40104 330 2000 1 13 5 20546 6803 33112 330 2000 1 7 0 20907 5779 27641 330 2500 1 7 5 10376 5068 48847 310 2000 1 7 5 11636 3606 30988 310 2000 1 7 20 9918 3602 36322 310 2000 1 7 10 9617 3524 36643 310 2000 1 7 0 13113 3442 26,250 310 2000 1 13 10 12604 3303 26202 310 1500 1 7 5 8833 3029 34295 310 2000 1 13 0 12882 2494 19357

Example A3

Synthesis of a Muitimetal Oxide with the Composition Cu _0.5 Mo _0.5 O ₂ (Variant with Calcination under Nitrogen):

The precursor of Example A was subjected in a rotary kiln to a subsequent calcination program. The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of nitrogen was adjusted. that a 10-fold volume exchange per hour was guaranteed. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 240 ° C was 2 hours. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a Cu molybdate with the CuMoO ₄ structure (medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) was detected.

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 2000 1 7 5 33361 10913 32713 330 2000 1 7 10 29319 9771 33327 330 1500 1 7 5 26154 9767 37343 330 2000 1 13 5 30281 9448 31201 330 2000 1 7 0 34981 8640 24698 330 2000 1 7 20 27010 7046 26086 330 2500 1 7 5 16243 6674 41090 310 2000 1 7 5 21026 5096 24236 310 2000 1 13 5 15589 4944 31717 310 2000 1 7 0 19457 4485 23052 310 2000 1 13 10 16457 4415 26826 310 2000 1 7 10 15913 4401 27654 310 2000 1 13 0 21306 3783 17754 310 2000 1 7 20 14013 3747 26741 290 2000 1 7 0 9946 2230 22426 275 2000 1 7 5 6566 1891 28795

Example B

Synthesis of a freeze-dried precursor for the preparation of multimetal oxides having the composition Cu _0.5 Mo _0.5 O ₂ :

you put aqueous ammonium heptamolybdate solution (1010 mL; 0.15 mol / l; 1.06 moles Mo) in a 2 liter beaker and dripped with vigorous stirring, aqueous copper nitrate solution (265 ml, 4 mol / l, 1.06 mol of Cu) through a 1-liter dropping funnel slowly too. The dripping rate was between 50-60 Drops per minute. After complete addition stirred the mixture for another 30 minutes. The solution was with Using a 1 ml pipette, slowly place in a dewar with liquid nitrogen, adding with a Magnetic stir bar touched. The frozen pellets were placed on metal dishes of 15 cm diameter (maximum bed height 0.5 cm) and in a freeze-drying plant of the company Christ at -30 ° C. heated. The main drying took place over several Stages. First, it was dried at -25 ° C. and 2.565 bar for 24 h, followed by drying over 24 h at -10 ° C and 2.565 bar and then Warming to 0 ° C.

To the removal of the pellets from the freeze-drying were these in Petri dishes at 80 ° C in a drying oven after-dried in air for 12 h.

The dried pellets were prepared by means of a compact (Powtec) compacted, to a fraction between 500 and 1000 microns classified.

Example B1

Synthesis of a multimetal oxide with the composition Cu _0.5 Mo _0.5 O ₂ (variant with calcination under air / nitrogen):

The precursor from Example B was subjected in a rotary kiln to a subsequent calcination program. The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of air was adjusted to provide a 10-fold volume exchange per hour. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 250 ° C was 2 hours. This was followed by switching to inert conditions (nitrogen) at a 10-fold volume exchange per hour. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination was again on a Fraction classified between 500 and 1000 microns. By XRD analysis, the formation of a Cu molybdate with the CuMoO ₄ structure (medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) was detected.

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 1500 1 7 5 30803 10764 34944 330 2000 1 7 10 32198 10222 31747 330 2000 1 7 5 36087 9981 27658 330 2000 1 13 5 33635 9287 27613 330 2000 1 7 20 37551 8802 23441 330 2000 1 7 0 38779 8086 20852 330 2500 1 7 5 20328 6944 34160 310 2000 1 7 10 15813 5311 33589 310 2000 1 13 5 18356 5176 28199 310 2000 1 7 5 15429 5165 33479 310 2000 1 13 10 20242 4918 24294 310 2000 1 7 0 14841 4809 32404 310 1500 1 7 5 13834 4615 33355 310 2000 1 7 20 15271 4601 30131 310 2000 1 13 0 16567 4028 24316 290 2000 1 7 10 10896 2377 21818

Example B2

Synthesis of a multimetal oxide with the composition Cu _0.5 Mo _0.5 O ₂ (variant with calcination under air):

The precursor from Example B was calcined in a rotary kiln as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of air was adjusted to provide a 10-fold volume exchange per hour. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 230 ° C was 2 hours. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a Cu molybdate with the CuMoO ₄ structure (medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) was detected.

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 360 4000 1 11 5 60789 23818 39182 340 2000 1 7 5 45641 20322 44526 350 2000 1 7 5 76272 19721 25857 330 2000 1 11 5 39561 15698 39681 350 2000 1 11 5 33991 15648 46036 330 2000 1 15 5 41183 14378 34912 330 2000 1 7 5 32224 12730 39505 340 2000 1 11 5 26472 12511 47263 360 4000 1 11 5 25823 11568 44798 340 2000 3 7 5 22996 10198 44344 330 2000 1 11 5 25021 9961 39810 350 4000 1 11 5 13473 9669 71768 310 2000 1 7 5 23961 9366 39089 350 8000 1 11 5 17429 9348 53636 340 4000 1 11 5 12,602 8946 70989 330 2000 1 15 5 24445 7545 30866 360 8000 1 11 5 9628 7534 78258 340 4000 1 7 5 14407 7102 49292 290 2000 1 7 5 21193 6957 32829 330 4000 1 7 5 14091 6078 43131 330 2000 3 11 5 13471 5678 42150 330 2000 3 7 5 12330 5427 44018 310 4000 1 7 5 15425 5364 34777 330 4000 1 11 5 10365 4934 47598 330 2000 3 4 5 10433 4911 47068 330 4000 1 15 5 13033 4822 36997 340 8000 1 11 5 9189 4705 51205 340 8000 1 7 5 10194 4363 42,800

Example B3

Synthesis of a multimetal oxide with the composition Cu _0.5 Mo _0.5 O ₂ (variant with calcination under nitrogen):

The precursor from Example B was calcined in a rotary kiln as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of nitrogen was adjusted. that a 10-fold volume exchange per hour was guaranteed. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 230 ° C was 2 hours. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a Cu molybdate with the CuMoO ₄ structure (medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) was detected.

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 2000 1 7 5 36356 11660 32073 330 2000 1 13 5 38451 10338 26886 330 2000 1 7 10 40163 10,200 25396 330 2000 1 7 0 43445 9178 21126 330 2000 1 7 20 31384 8734 27830 330 1500 1 7 5 41469 8449 20375 330 2500 1 7 5 23824 8212 34470 310 2000 1 7 5 24451 6068 24818 310 2000 1 13 10 21546 5619 26078 310 2000 1 13 5 24275 5583 22999 310 2000 1 7 10 20,333 5550 27294 310 1500 1 7 5 14139 5162 36508 310 2000 1 7 0 27965 5132 18350 310 2000 1 13 0 23,184 4591 19802 310 2000 1 7 20 21023 4374 20805 290 2000 1 7 10 11141 2616 23484

Example C

Synthesis of a spray-dried precursor for the preparation of multimetal oxides having the composition Cu _0.5 Mo _0.5 O ₂ :

you put aqueous ammonium heptamolybdate solution (1010 ml; 0.15 mol / l; 1.06 moles Mo) in a 2 liter beaker and dripped with vigorous stirring, aqueous copper nitrate solution (265 mL, 4 mol / L, 1.06 moles of Cu) through a 1 L dropping funnel slowly too. The dripping rate was between 50-60 Drops per minute. After complete addition stirred the mixture for another 30 min.

The Solution was in a with the help of a peristaltic pump Spray tower initiated. The spray tower inlet temperature was 350 ° C and the tower exit temperature 120 ° C. The pumping speed was adjusted so that an exit temperature of 105 ° C was not exceeded. The powder was in Petri dishes at 80 ° C in a drying oven for 12 h in air dried.

The obtained powder was compacted to a fraction between 500 and 1000 μm classified.

Example C1

Synthesis of a multimetal oxide with the composition Cu _0.5 Mo _0.5 O ₂ (variant with calcination under air / nitrogen):

The precursor from Example C was calcined in a rotary kiln as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of air was adjusted to provide a 10-fold volume exchange per hour. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 250 ° C was 2 hours. This was followed by switching to inert conditions (nitrogen) at a 10-fold volume exchange per hour. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a Cu molybdate with the CuMoO ₄ structure (medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) was detected.

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 2000 1 7 5 55697 14716 26421 330 1500 1 7 5 40381 13510 33455 330 2000 1 7 10 45559 12805 28107 330 2000 1 7 0 67294 12004 17838 330 2000 1 13 5 35894 11540 32150 310 2000 1 7 5 49725 11063 22248 330 2000 1 7 20 31668 9866 31154 310 2000 1 7 0 54642 9815 17962 310 2000 1 7 10 43409 9644 22216 310 2000 1 13 5 30914 9146 29587 330 2500 1 7 5 18846 8610 45685 310 2000 1 13 10 29223 8419 28810 290 2000 1 7 5 30732 7522 24477 310 2000 1 13 0 32692 7438 22753 310 2000 1 7 20 37226 7404 19889 290 2000 1 7 10 27333 6618 24212 290 2000 1 7 0 36159 6322 17483 250 2000 1 7 5 12039 1507 12519

Example C2

Synthesis of a multimetal oxide with the composition Cu _0.5 Mo _0.5 O ₂ (variant with calcination under air):

The precursor from Example C was calcined in a rotary ball furnace as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of air was adjusted. that a 10-fold volume exchange per hour was guaranteed. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 240 ° C was 2 hours. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a Cu molybdate with the CuMoO ₄ structure (medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) was detected.

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 2000 1 7 5 59471 14467 24325 330 1500 1 7 5 33849 13554 40042 330 2000 1 7 10 47715 13162 27584 330 2000 1 7 0 71615 11974 16720 330 2000 1 13 5 35074 11948 34,066 310 2000 1 7 5 45585 11440 25096 330 2000 1 7 20 35121 10478 29833 310 2000 1 13 5 40668 10180 25031 310 2000 1 7 0 54370 9840 18099 310 2000 1 7 10 40568 9664 23822 330 2500 1 7 5 19253 8889 46172 310 2000 1 13 10 31684 8849 27929 310 2000 1 13 0 33022 8062 24414 310 2000 1 7 20 37444 7658 20,452 290 2000 1 7 5 24139 7369 30,528 290 2000 1 7 10 25,194 5783 22955 290 2000 1 7 0 19277 5604 29,072 275 2000 1 7 5 9623 4735 49212

Example C3

Synthesis of a multimetal oxide with the composition Cu _0.5 Mo _0.5 O ₂ (variant with calcination under nitrogen):

The precursor from Example C was calcined in a rotary ball furnace as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of nitrogen was adjusted. that a 10-fold volume exchange per hour was guaranteed. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 240 ° C was 2 hours. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a Cu molybdate with the CuMoO ₄ structure (medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) was detected.

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 2000 1 7 5 61189 14893 24339 330 2000 1 7 10 50045 13499 26974 330 1500 1 7 5 43027 13227 30740 330 2000 1 7 0 69998 12837 18339 330 2000 1 13 5 39797 12064 30314 330 2000 1 7 20 42856 11457 26734 310 2000 1 7 5 48236 11268 23359 310 2000 1 7 10 43837 10555 24078 310 2000 1 13 5 33672 10253 30449 310 2000 1 7 0 59757 9894 16556 310 2000 1 13 10 32286 9480 29362 330 2500 1 7 5 23671 9430 39836 310 2000 1 7 20 39754 9159 23039 310 2000 1 13 0 35265 7938 22510 290 2000 1 7 5 32693 7302 22335 290 2000 1 7 10 28783 6753 23463 290 2000 1 7 0 31665 5977 18877 310 1500 1 7 5 14319 5882 41079 275 2000 1 7 5 14284 5108 35763

Example D

Synthesis of a freeze-dried precursor for the preparation of multimetal oxides with the composition Cu _0.55 Mo _0.45 O _1.9 :

you put aqueous ammonium heptamolybdate solution (184 ml; 0.15 mol / l; 0.19 mol Mo) in a 1 L beaker and dripped with vigorous stirring, aqueous copper nitrate solution (59 ml, 4 mol / L, 0.236 mol Cu) through a 1 L dropping funnel slowly too. The dripping rate was between 50-60 Drops per minute. After complete addition stirred the mixture for another 30 minutes. The solution was with Using a 1 ml pipette, slowly place in a dewar with liquid nitrogen, adding with a Magnetic stir bar touched. The frozen pellets were placed on metal dishes of 15 cm diameter (maximum bed height 0.5 cm) and in a freeze-drying plant of the company Christ at -30 ° C. heated. The main drying took place over several Stages. First, it was dried at -25 ° C. and 2.565 bar for 24 h, followed by drying over 24 h at -10 ° C and 2.565 bar and then Warming to 0 ° C.

To the removal of the pellets from the freeze-drying were these in Petri dishes at 80 ° C in a drying oven after-dried in air for 12 h.

The dried pellets were prepared by means of a compact (Powtec) compacted, to a fraction between 500 and 1000 microns classified

Example D1

Synthesis of a multimetal oxide with the composition Cu _0.55 Mo _0.45 O _1.9 (variant with calcination under air / nitrogen):

The precursor from Example D was calcined in a rotary kiln as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of air was adjusted to provide a 10-fold volume exchange per hour. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 250 ° C was 2 hours. This was followed by switching to inert conditions (nitrogen) at a 10-fold volume exchange per hour. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a mixture of Cu-Molybdaten with the CuMoO ₄ structure (main product, medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) and with the Cu ₃ Mo ₂ O ₉ - Structure (by-product, index card 00-024-0055 of the ICDD PDF-2 Index, Release 2006).

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 2500 1 7 5 51930 11551 22243 310 2000 1 7 20 42903 10159 23680 310 2000 1 13 10 32589 9960 30564 310 2000 1 7 10 44555 9699 21770 310 1500 1 7 5 24315 9657 39718 330 2000 1 7 20 65430 9353 14295 310 2000 1 13 5 37632 9093 24162 330 2000 1 7 10 64276 8759 13627 310 2000 1 7 5 45404 8755 19283 330 2000 1 7 5 68614 8058 11744 330 1500 1 7 5 68295 7540 .11.040 330 2000 1 13 5 67350 7317 10864 310 2000 1 13 0 34416 7229 21004 310 2000 1 7 0 49561 7148 14423 290 2000 1 7 10 30403 6,897 22686 330 2000 1 7 0 66781 6895 10325 290 2000 1 7 5 35220 6635 18840 290 2000 1 7 0 35688 5296 14841 275 2000 1 7 5 16087 4963 30848

Example D2

Synthesis of a multimetal oxide with the composition Cu _0.55 Mo _0.45 O _1.9 (variant with calcination in air):

The precursor from Example D was calcined in a rotary kiln as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of air was adjusted. that a 10-fold volume exchange per hour was guaranteed. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 240 ° C was 2 hours. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a mixture of Cu-Molybdaten with the CuMoO ₄ structure (main product, medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) and with the Cu ₃ Mo ₂ O ₉ - Structure (by-product, index card 00-024-0055 of the ICDD PDF-2 Index, Release 2006).

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 2500 1 7 5 69658 15021 21564 310 2000 1 13 5 51244 11869 23161 310 1500 1 7 5 48591 11744 24170 310 2000 1 7 5 65448 10856 16587 310 2000 1 13 10 48819 10837 22198 310 2000 1 7 10 63799 10232 16038 310 2000 1 13 0 46620 9520 20421 310 2000 1 7 0 62987 9498 15,079 330 2000 1 7 5 88628 9477 10693 330 2000 1 7 10 87523 8753 10001 330 2000 1 13 5 87179 8710 9991 310 2000 1 7 20 58341 8616 14768 290 2000 1 7 5 50148 8097 16147 330 2000 1 7 20 85609 7967 9307 290 2000 1 7 10 47728 7865 16478 330 2000 1 7 0 89590 7250 8092 290 2000 1 7 0 47329 7138 15083 275 2000 1 7 5 29690 6934 23354 330 1500 1 7 5 91198 6798 7454

Example D3

Synthesis of a multimetal oxide with the composition Cu _0.55 Mo _0.45 O _1.9 (variant with calcination under nitrogen):

The precursor from Example D was calcined in a rotary kiln as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of nitrogen was adjusted. that a 10-fold volume exchange per hour was guaranteed. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 230 ° C was 2 hours. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a mixture of Cu-Molybdaten with the CuMoO ₄ structure (main product, medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) and with the Cu ₃ Mo ₂ O ₉ - Structure (by-product, index card 00-024-0055 of the ICDD PDF-2 Index, Release 2006).

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 2500 1 7 5 66182 15872 23983 310 2000 1 13 10 48433 12798 26424 310 1500 1 7 5 43640 12371 28347 310 2000 1 13 5 48918 12152 24842 310 2000 1 7 5 62635 12021 19192 310 2000 1 7 10 56632 11514 20332 310 2000 1 7 20 57844 11103 19195 330 2000 1 13 5 85990 11093 12,900 330 2000 1 7 5 88690 10472 11807 310 2000 1 7 0 60010 10398 17326 330 2000 1 7 20 86746 10044 11579 330 2000 1 7 10 88705 9781 11027 310 2000 1 13 0 44357 9129 20581 330 2000 1 7 0 89435 8663 9687 290 2000 1 7 5 51279 8210 16010 290 2000 1 7 10 46106 8206 17798 275 2000 1 7 5 29941 6815 22762 290 2000 1 7 0 48172 6798 14112 330 1500 1 7 5 93380 6298 6745

Example E

Synthesis of a freeze-dried precursor for the preparation of multimetal oxides having the composition Cu _0.4 Mo _0.6 O _2.2 :

you put aqueous ammonium heptamolybdate solution (224 ml; 0.15 mol / l; 0.235 mol Mo) in a 1 liter beaker and dripped with vigorous stirring, aqueous copper nitrate solution (40 ml, 4 mol / L, 0.16 mol of Cu) through a 1-liter dropping funnel slowly too. The dripping rate was between 50-60 Drops per minute. After complete addition stirred the mixture for another 30 minutes. The solution was with Using a 1 ml pipette, slowly place in a dewar with liquid nitrogen, adding with a Magnetic stir bar touched. The frozen pellets were placed on metal dishes of 15 cm diameter (maximum bed height 0.5 cm) and in a freeze-drying plant of the company Christ at -30 ° C. heated. The main drying took place over several Stages. First, it was dried at -25 ° C. and 2.565 bar for 24 h, followed by drying over 24 h at -10 ° C and 2.565 bar and then Warming to 0 ° C.

To the removal of the pellets from the freeze-drying were these in Petri dishes at 80 ° C in a drying oven after-dried in air for 12 h.

The dried pellets were prepared by means of a compact (Powtec) compacted, to a fraction between 500 and 1000 microns classified

Example E1

Synthesis of a Muitimetal Oxide with the Composition Cu _0.4 Mo _0.6 O _2.2 (Variant with Calcination Under Air / Nitrogen):

The precursor from Example E was calcined in a rotary kiln as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of air was adjusted to provide a 10-fold volume exchange per hour. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 250 ° C was 2 hours. This was followed by switching to inert conditions (nitrogen) at a 10-fold volume exchange per hour. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a mixture of a Cu molybdate with the CuMoO ₄ structure (main product, medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) and MoO ₃ (by-product, index card 00- 005-0508 of the ICDD PDF-2 file, release 2006).

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 2000 1 7 10 46880 12926 27573 330 1500 1 7 5 46727 12680 27135 330 2000 1 13 5 41811 12370 29586 330 2000 1 7 5 56159 12262 21835 330 2000 1 7 20 48632 11960 24592 330 2000 1 7 0 58196 11120 19107 330 2500 1 7 5 29381 9827 33446 310 2000 1 7 5 28421 8575 30170 310 2000 1 13 5 31031 8,524 27469 310 2000 1 13 10 29817 8486 28458 310 2000 1 7 10 35792 8293 23169 310 2000 1 7 20 27344 7896 28877 310 2000 1 7 0 29986 7408 24703 310 2000 1 13 0 31417 6589 20974 310 1500 1 7 5 18282 6042 33050 290 2000 1 7 5 13060 4804 36781 290 2000 1 7 10 15761 4268 27079 290 2000 1 7 0 13702 3945 28789

Example E2

Synthesis of a multimetal oxide with the composition Cu _0.4 Mo _0.6 O _2.2 (variant with calcination under air):

The precursor from Example E was calcined in a rotary kiln as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of air was adjusted. that a 10-fold volume exchange per hour was guaranteed. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 230 ° C was 2 hours. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a mixture of a Cu molybdate with the CuMoO ₄ structure (main product, medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) and MoO ₃ (by-product, index card 00- 005-0508 of the ICDD PDF-2 file, release 2006).

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 1500 1 7 5 56497 12981 22977 330 2000 1 7 10 45180 12825 28387 330 2000 1 7 5 52052 12435 23890 330 2000 1 13 5 52813 12266 23226 330 2000 1 7 20 50741 11339 22347 330 2000 1 7 0 46620 10898 23376 330 2500 1 7 5 28231 10526 37285 310 1500 1 7 5 27206 7105 26117 310 2000 1 13 10 21866 6366 29116 310 2000 1 13 5 20961 6165 29412 310 2000 1 7 5 20313 5837 28737 310 2000 1 7 10 16194 5681 35084 310 2000 1 7 20 18303 5504 30071 310 2000 1 13 0 16925 5127 30294 310 2000 1 7 0 15613 5083 32558

Example E3

Synthesis of a multimetal oxide with the composition Cu _0.4 Mo _0.6 O _2.2 (variant with calcination under nitrogen):

The precursor from Example E was calcined in a rotary kiln as follows: The heating rate 1 was 1 K / min. The target temperature 1 was 120 ° C. The breakpoint at target temperature 120 ° C was 2 hours. The flow of nitrogen was adjusted. that a 10-fold volume exchange per hour was guaranteed. The heating rate to the target temperature 2 was 1 K / min. The breakpoint at target temperature 230 ° C was 2 hours. The heating rate to the final temperature was 1 K / min. The final temperature was 330 ° C with a breakpoint of 2 h. After calcination, the mixture was again classified to a fraction between 500 and 1000 μm. By XRD analysis, the formation of a mixture of a Cu molybdate with the CuMoO ₄ structure (main product, medium pressure modification, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) and MoO ₃ (by-product, index card 00- 005-0508 of the ICDD PDF-2 file, release 2006).

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 330 1500 1 7 5 49798 12960 26025 330 2000 1 7 5 51001 12518 24,544 330 2000 1 7 10 48495 11928 24597 330 2000 1 13 5 46403 11819 25470 330 2000 1 7 20 44927 11201 24932 330 2000 1 7 0 55530 10593 19076 330 2500 1 7 5 29502 9127 30938 310 2000 1 7 5 16802 7108 42305 310 2000 1 13 5 25801 6955 26956 310 2000 1 7 10 21904 6952 31738 310 2000 1 13 10 26442 6919 26166 310 2000 1 7 20 26510 6561 24748 310 2000 1 13 0 20728 5850 28223 310 2000 1 7 0 19297 5619 29,120 250 2000 1 7 5 15458 0683 4420

Example F

Hydrothermal synthesis of a multimetal oxide with the composition Cu _0.4 Mo _0.6 O ₂ :

Was placed in a 2.5 liter autoclave (Material HC-4, material no .: 2.4610) 28.6 g of Cu ₂ O (0.4 mole Cu), 90.7 g MoO ₃ (0.63 mol Mo ) and 1200 g of deionized water. The autoclave was purged five times with nitrogen (20 bar), heated with stirring (700 rpm) to 300 ° C and kept at this temperature for 12 hours under nitrogen. The autogenous pressure was 133 bar. After 12 hours, the autoclave was cooled to room temperature and depressurized. The product was filtered off with suction through a glass filter funnel and dried in a muffle furnace at 80 ° C. for 5 hours. By XRD analysis, the formation of a Cu molybdate was detected with the Cu ₄ Mo ₆ O ₂₀ structure (tab 01-078-0380 of the ICDD PDF-2 file, release 2006).

The dried product was compacted by means of a compact (Paul-Otto Weber GmbH) and classified to a fraction between 500 and 1000 μm. The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 270 2000 1 7 5 16.2 3.1 19.2 290 2000 1 7 5 16.5 5.2 31.2 300 2000 1 7 5 23.1 7.3 31.5 310 2000 1 7 5 19.6 8.8 44.7 330 1500 1 7 5 42.9 9.6 22.3 330 2000 1 7 5 53.5 12.0 22.4 330 2000 1 7 5 28.4 9.6 33.9 330 2000 1 11 5 49.7 12.4 24.9 330 2000 1 15 5 49.0 11.8 24.1 330 2000 2 7 5 26.6 4.8 18.1 330 2000 3 7 5 12.3 3.6 29.0 330 2500 1 7 5 21.9 8.4 38.2 340 1500 1 7 5 59.3 13.4 22.5 340 1500 3 7 5 23.3 5.5 23.5 340 1750 1 7 5 53.0 12.2 22.9 340 2000 1 7 5 52.2 12.5 24.0 340 2000 1 7 10 51.2 12.3 24.0 340 2000 1 11 5 59.3 13.5 22.8 340 2000 1 15 5 64.3 14.0 21.7 340 2000 2 7 5 11.0 3.6 32.7 340 2000 3 7 5 16.4 4.7 28.6 340 2250 1 7 5 44.2 11.6 26.3 340 2500 1 7 5 44.3 10.6 23.8 340 2500 3 7 5 14.2 3.9 27.8 350 1500 1 7 5 83.8 9.7 11.6 350 2000 1 7 5 67.5 12.3 18.3 350 2500 1 7 5 51.7 13.8 26.7

Example G

Hydrothermal synthesis of a multimetal _oxide with the composition Cu _0.44 Mo _0.56 O _1.9 :

36.1 g of Cu ₂ O (0.50 mol of Cu), 90.7 g of MoO ₃ (0.63 mol Mo.) Were placed in a 2.5 l autoclave (material HC-4, material no .: 2.4610) ) and 1200 g of deionized water. The autoclave was purged five times with nitrogen (20 bar), heated with stirring (700 rpm) to 300 ° C and kept at this temperature for 12 hours under nitrogen. The autogenous pressure was 90 bar. After 12 hours, the autoclave was cooled to room temperature and depressurized. The product was filtered off with suction through a glass filter funnel and dried in a muffle furnace at 80 ° C. for 5 hours. By XRD analysis, the formation of a Cu molybdate with the Cu ₄ Mo ₅ O ₁₇ structure (tab 01-084-1106 of the ICDD PDF-2 file, release 2006) was detected.

The dried product was compacted by means of a compact (Paul-Otto Weber GmbH) and classified to a fraction between 500 and 1000 μm. The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 270 2000 1 7 5 11.8 6.5 53.7 290 2000 1 7 5 20.9 6.1 29.2 300 2000 1 7 5 25.9 7.6 29.5 310 2000 1 7 5 33.9 10.7 31.7 330 1500 1 7 5 50.1 7.0 14.0 330 2000 1 7 5 82.0 11.0 13.4 330 2000 1 7 5 41.7 8.9 21.4 330 2000 1 11 5 72.5 11.7 16.1 330 2000 1 15 5 70.6 10.4 14.8 330 2000 2 7 5 32.1 6.7 21.0 330 2000 3 7 5 24.9 4.7 19.0 330 2500 1 7 5 34.6 10.9 31.4 340 1500 1 7 5 63.6 4.4 6.9 340 1500 3 7 5 22.5 6.3 28.0 340 1750 1 7 5 61.5 5.9 9.6 340 2000 1 7 5 51.1 8.8 17.3 340 2000 1 7 10 69.6 6.6 9.5 340 2000 1 11 5 58.9 7.0 11.9 340 2000 1 15 5 71.0 3.9 5.4 340 2000 2 7 5 23.8 4.8 20.1 340 2000 3 7 5 28.2 8.4 29.8 340 2250 1 7 5 69.3 7.9 11.5 340 2500 1 7 5 62.5 9.8 15.7 340 2500 3 7 5 22.7 7.1 31.5 350 1500 1 7 5 67.3 3.9 5.8 350 2000 1 7 5 70.6 4.4 6.3 350 2500 1 7 5 68.7 7.0 10.3

Example H

Hydrothermal synthesis of a multimetal oxide with the composition Cu _0.55 Mo _0.45 O _1.63 :

51.5 g of Cu ₂ O (0.72 mol of Cu), 90.7 g of MoO ₃ (0.63 mol of Mo) and, in a 2.5 liter autoclave (material HC-4, material no .: 2.4610) 1200 g of demineralized water. The autoclave was purged five times with nitrogen (20 bar), heated with stirring (700 rpm) to 300 ° C and kept at this temperature for 12 hours under nitrogen. The autogenous pressure was 90 bar. After 12 hours, the autoclave was cooled to room temperature and depressurized. The product was filtered off with suction through a glass filter funnel and dried in a muffle furnace at 80 ° C. for 5 hours. By XRD analysis, the formation of a Cu molybdate was detected with the Cu ₆ Mo ₅ O ₁₈ structure (tab 01-084-0842 of the ICDD PDF-2 file, release 2006).

The dried product was compacted by means of a compact (Paul-Otto Weber GmbH) and classified to a fraction between 500 and 1000 μm. The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 270 2000 1 7 5 4.7 2.4 50.3 290 2000 1 7 5 9.2 5.6 60.7 300 2000 1 7 5 16.7 7.2 43.5 310 2000 1 7 5 29.9 8.2 27.3 330 1500 1 7 5 54.4 9.8 18.0 330 2000 1 7 5 42.4 10.9 25.7 330 2000 1 7 5 57.9 8.4 14.5 330 2000 1 11 5 51.4 6.5 12.6 330 2000 1 15 5 52.5 5.8 11.0 330 2000 2 7 5 28.0 6.9 24.5 330 2000 3 7 5 25.0 6.5 25.9 330 2500 1 7 5 30.2 11.9 39.3 340 1500 1 7 5 73.3 7.2 9.8 340 1500 3 7 5 33.2 10.7 32.2 340 1750 1 7 5 64.0 9.6 15.0 340 2000 1 7 5 59.6 8.7 14.5 340 2000 1 7 10 64.1 8.4 13.0 340 2000 1 11 5 67.0 6.6 9.9 340 2000 1 15 5 64.3 6.7 10.5 340 2000 2 7 5 24.0 6.6 27.4 340 2000 3 7 5 29.3 9.2 31.5 340 2250 1 7 5 61.5 9.2 15.0 340 2500 1 7 5 54.9 9.3 16.9 340 2500 3 7 5 27.1 9.3 34.4 350 1500 1 7 5 91.8 4.9 5.4 350 2000 1 7 5 88.1 6.4 7.2 350 2500 1 7 5 67.4 12.6 18.7

Example 2:

Examples 2.1-2.3 describe the preparation of multimetal oxides having the general composition Cu _a Mo _b M _c O _d

Example 2.1

Synthesis of a multimetal _oxide with the composition Cu _0.495 Mo _0.5 Bi _0.005 O _d

Three aqueous solutions of metal sources were first prepared. Solution 1 contained 176.6 g of ammonium heptamolybdate (MoO ₃ content = 81.53% by weight, 1.0 mol of Mo) in 3 l of demineralized water at 60 ° C., solution 2 contained 196.6 g of copper acetate ( Cu content = 32 wt%, 0.99 mol Cu) in 3 L of deionized water, and the solution 3 contained 4.86 g of bismuth nitrate (Bi content = 43 wt%, 0.01 mol) in 12 , 5 g HNO ₃ (65 wt .-%) and 12.5 g of deionized water. Solution 1 was introduced into an 8 l glass reactor and the solutions 2 and 3 were slowly added dropwise with vigorous stirring. Further, 87.1 g of ammonia solution (25 wt%) was added. The resulting suspension was heated to 80 ° C, held for 4 hours at this temperature and cooled to room temperature. The suspension was then spray-dried in a spray tower (Niro Inc., Mobile Minor 2000). The resulting powder was calcined in air in a rotary kiln at 300 ° C for 12 hours. By means of XRD analysis, the medium-pressure modification of the CuMoO ₄ structure (index card 01-085-1530 of the ICDD PDF-2 file, release 2006).

The calcined product was compacted by means of a compact (Paul-Otto Weber GmbH) and classified to a fraction between 500 and 1000 μm. The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 270 2000 1 7 5 3.1 2.3 75.2 290 2000 1 7 5 14.1 4.8 34.0 310 2000 1 7 5 24.8 7.8 31.6 320 2000 1 7 5 34.6 9.7 28.0 330 2000 1 7 5 52.0 13.0 24.9 330 2000 1 4 5 52.3 15.1 28.8 330 2000 1 11 5 64.0 16.8 26.2 330 2000 1 7 10 54.6 17.2 31.5 330 2500 1 7 5 38.7 16.9 43.6 330 2500 1 11 5 45.2 17.4 38.6 330 3000 1 11 5 35.3 16.8 47.7 320 2000 1 4 5 29.8 13.6 45.6 320 2000 1 11 5 32.0 14.3 44.5 320 2000 1 7 10 26.6 15.1 56.9 320 2500 1 7 5 25.5 11.9 46.7 320 2500 1 11 5 29.0 13.3 45.9 340 2000 1 7 5 63.5 19.1 30.1 350 2000 1 7 5 82.1 15.3 18.7 330 2000 2 7 5 19.4 9.9 51.0 330 2000 2 11 5 20.4 10.5 51.6 330 2000 3 7 5 10.0 7.4 74.2 330 2000 3 11 5 14.6 7.6 52.3 320 2000 2 7 5 13.3 6.2 46.8

The XRD analysis of the powder after removal of the sample from the reactor showed the conversion of the medium-pressure modification of the CuMoO ₄ structure into the high-pressure modification of the CuMoO ₄ structure (tab 01-077-0699 of the ICDD PDF-2 file, release 2006).

Example 2.2

Synthesis of a multimetal _oxide with the composition Cu _0.475 Mo _0.5 Bi _0.025 O _d

Three aqueous solutions of metal sources were first prepared. Solution 1 contained 176.6 g of ammonium heptamolybdate (MoO ₃ content = 81.53% by weight, 1.0 mol of Mo) in 3 l of deionized water at 60 ° C., solution 2 contained 188.7 g of copper acetate ( Cu content = 32 wt%, 0.95 mol Cu) in 3 L of deionized water, and the solution 3 contained 24.3 g of bismuth nitrate (Bi content = 43 wt%, 0.05 mol) in 50 g g HNO ₃ (65 wt .-%) and 50 g of deionized water. Solution 1 was introduced into an 8 l glass reactor and the solutions 2 and 3 were slowly added dropwise with vigorous stirring. Further, 116.4 g of ammonia solution (25 wt%) was added. The resulting suspension was heated to 80 ° C, held for 4 hours at this temperature and cooled to room temperature. The suspension was then spray-dried in a spray tower (Niro Inc., Mobile Minor 2000). The resulting powder was calcined in air in a rotary kiln at 300 ° C for 12 hours. By means of XRD analysis, the medium-pressure modification of the CuMoO ₄ structure (main product, index card 01-085-1530 of the ICDD PDF-2 Index, Release 2006) and Bi ₂ Mo ₃ O ₁₂ (by-product, index card 00-021-0103 of the ICDD PDF-2 Index, Release 2006).

The calcined product was compacted by means of a compact (Paul-Otto Weber GmbH) and classified to a fraction between 500 and 1000 μm. The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 290 2000 1 7 5 24.3 6.6 27.2 310 2000 1 7 5 44.2 10.9 24.6 320 2000 1 7 5 43.2 15.0 34.8 330 2000 1 7 5 67.7 17.7 26.1 330 2000 1 4 5 47.1 19.3 41.0 330 2000 1 11 5 63.2 17.7 28.0 330 2000 1 7 10 61.6 17.7 28.7 330 2500 1 7 5 52.0 19.6 37.7 330 2500 1 11 5 52.1 18.6 35.8 330 3000 1 11 5 41.2 17.5 42.6 320 2000 1 4 5 31.9 16.5 51.7 320 2000 1 11 5 45.4 15.8 34.8 320 2000 1 7 10 31.0 16.4 52.8 320 2500 1 7 5 38.5 14.0 36.4 320 2500 1 11 5 32.5 14.8 45.7 340 2000 1 7 5 79.4 16.0 20.1 350 2000 1 7 5 92.7 9.8 10.5 330 2000 2 7 5 39.2 14.3 36.5 330 2000 2 11 5 36.2 14.9 41.1 330 2000 3 7 5 25.0 11.1 44.5 330 2000 3 11 5 26.7 11.3 42.3 320 2000 2 7 5 19.7 9.5 48.2

The XRD analysis of the powder after removal of the sample from the reactor showed the conversion of the medium-pressure modification of the CuMoO ₄ structure into the high-pressure modification of the CuMoO ₄ structure (main product, tab 01-077-0699 of the ICDD PDF-2 file, release 2006 ). As by-product Bi ₂ Mo ₃ O ₁₂ (tab 00-021-0103 of the ICDD PDF-2 file, release 2006) has been detected

Example 2.3

Synthesis of a multimetal oxide with the composition Cu _0.45 Mo _0.5 Bi _0.05 O _d

Three aqueous solutions of metal sources were first prepared. Solution 1 contained 176.6 g of ammonium heptamolybdate (MoO ₃ content = 81.53% by weight, 1.0 mol of Mo) in 3 l of demineralized water at 60 ° C., solution 2 contained 178.7 g of copper acetate ( Cu content = 32 wt .-%, 0.9 mol of Cu) in 3 l of deionized water and the solution 3 contained 48.6 g of bismuth nitrate (Bi content = 43 wt .-%, 0.1 mol of Bi) in 100 g of HNO ₃ (65 wt .-%) and 100 g of deionized water. Solution 1 was introduced into an 8 l glass reactor and the solutions 2 and 3 were slowly added dropwise with vigorous stirring. Further, 154.6 g of ammonia solution (25 wt%) was added. The resulting suspension was heated to 80 ° C, held for 4 hours at this temperature and cooled to room temperature. The suspension was then spray-dried in a spray tower (Niro Inc., Mobile Minor 2000). The resulting powder was calcined in air in a rotary kiln at 300 ° C for 12 hours. By means of XRD analysis, the medium-pressure modification of the CuMoO ₄ structure (main product, index card 01-085-1530 of the ICDD PDF-2 file, release 2006) and Bi ₂ Mo ₃ O ₁₂ (by-product, index card 00-021-0103 of the ICDD PDF -2 file, release 2006).

The calcined product was compacted by means of a compact (Paul-Otto Weber GmbH) and classified to a fraction between 500 and 1000 μm. The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 270 2000 1 7 5 4.9 3.2 65.3 290 2000 1 7 5 16.1 7.6 47.0 310 2000 1 7 5 32.4 13.4 41.5 320 2000 1 7 5 45.5 16.9 37.1 330 2000 1 7 5 61.1 18.0 29.5 330 2000 1 4 5 57.9 19.6 33.9 330 2000 1 11 5 66.9 18.5 27.7 330 2000 1 7 10 65.1 19.6 30.1 330 2500 1 7 5 56.6 19.1 33.7 330 2500 1 11 5 50.3 20.0 39.7 330 3000 1 11 5 42.2 17.7 42.1 320 2000 1 4 5 35.7 17.1 47.9 320 2000 1 11 5 44.6 16.4 36.8 320 2000 1 7 10 39.1 17.0 43.6 320 2500 1 7 5 32.0 15.1 47.3 320 2500 1 11 5 31.4 15.9 50.6 340 2000 1 7 5 83.7 16.0 19.2 350 2000 1 7 5 94.9 9.1 9.6 330 2000 2 7 5 44.6 14.7 32.9 330 2000 2 11 5 34.4 16.0 46.6 330 2000 3 7 5 21.8 12.4 56.7 330 2000 3 11 5 26.3 12.3 46.9 320 2000 2 7 5 20.8 9.7 46.9

The XRD analysis of the powder after removal of the sample from the reactor showed the conversion of the medium-pressure modification of the CuMoO ₄ structure into the high-pressure modification of the CuMoO ₄ structure (main product, tab 01-077-0699 of the ICDD PDF-2 file, release 2006 ). Bi ₂ Mo ₃ O ₁₂ (tab: 00-021-0103 of the ICDD PDF-2 file, release 2006) and Bi ₂ MoO ₆ (tab 01-084-0787 of the ICDD PDF-2 file, release 2006) were detected as by-products

Example 3:

Examples 3.1-3.7 describe the impregnation of multimetal oxides of the general composition Cu _a Mo _b M _c O _d · eH ₂ O where c = 0 with metal salt solutions. The resulting masses decompose to multimetal oxides during the catalytic tests. The water uptake capacity of the starting multimetal oxide was first determined on an aliquot and then the multimetal oxide was impregnated with a corresponding volume of metal salt solution.

Example 3.1: Precursor for the preparation of a multimetal _{oxide of} the composition Cu _0.495 Mo _0.495 Bi _0.01 O _d (impregnation of Cu _0.5 Mo _0.5 O ₂ with 1.210% by weight antimony):

The Fraction between 500 and 1000 microns from the example Al was with aqueous antimony acetate solution (containing 12.1 mg Sb / 1 g fraction Al) on a shaker in a Porcelain bowl soaked. Subsequently, the Sample dried at 80 ° C under air, to 500 to 1000 microns classified.

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 340 2250 1 7 5 53.278 16535 31036 350 2500 1 7 5 76330 16481 21591 340 1500 1 7 5 68965 16096 23339 340 2500 1 7 5 52314 15411 29459 330 1500 1 7 5 47009 15365 32687 340 1750 1 7 5 68478 15037 21958 340 2000 1 7 10 74578 13728 18408 330 2000 1 7 5 39774 13284 33398 330 2500 1 7 5 14178 13281 93669 350 2000 1 7 5 86263 12943 15004 340 2000 1 7 5 80024 12843 16049 330 2000 1 11 5 82417 12196 14798 330 2000 1 15 5 85674 11561 13494 340 2000 1 11 5 87480 11396 13027 310 2000 1 7 5 30158 10097 33481 340 1500 3 7 5 30519 10,000 32,768 330 2000 2 7 5 33708 9735 28880 340 2000 3 7 5 21511 8602 39988 340 2000 1 15 5 94722 8055 8504 300 2000 1 7 5 25971 7981 30731 350 1500 1 7 5 94748 7450 7863 340 2500 3 7 5 17178 7192 41866 290 2000 1 7 5 22371 6973 31171 270 2000 1 7 5 18765 5963 31779 250 2000 1 7 5 10237 3364 32865

Example 3.2: Precursor for the preparation of multimetal _oxide of composition Cu _0.52 Mo _0.48 O ₂ (impregnation of Cu _0.5 Mo _0.5 O ₂ with 2.37 wt% copper):

The Fraction between 500 and 1000 microns from Example C2 was with aqueous copper nitrate solution (containing 23.7 mg Cu / 1 g fraction C2) on a shaker in a Porcelain bowl soaked. Subsequently, the Sample dried at 80 ° C under air, to 500 to 1000 microns classified.

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-Tolylaldehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 360 4000 1 11 5 32746 22063 67376 350 2000 1 7 5 72504 21686 29910 340 2000 1 7 5 52182 19922 38178 340 2000 1 11 5 56329 19862 35261 350 4000 1 11 5 38284 18962 49530 330 2000 1 15 5 38959 17695 45420 340 4000 1 11 5 27292 16745 61353 330 2000 1 11 5 57261 16636 29053 340 4000 1 7 5 29813 15770 52897 360 8000 1 11 5 21790 15523 71237 330 2000 1 7 5 79275 15437 19472 310 2000 1 7 5 51495 14315 27799 330 4000 1 7 5 46273 13703 29613 330 4000 1 15 5 19728 13624 69060 350 8000 1 11 5 14503 13526 93269 360 4000 3 15 5 22942 12526 54596 330 4000 1 11 5 35733 12287 34385 340 2000 3 15 5 28145 11906 42303 340 2000 3 7 5 25146 11852 47134 330 2000 3 7 5 29599 10983 37106 350 400 3 11 5 23051 10098 43806 340 8000 1 11 5 18525 10089 54462 340 8000 1 7 5 17134 9785 57111 330 2000 3 11 5 26884 9512 35382 330 2000 3 4 5 21939 9476 43192 330 1500 3 7 5 34146 9378 27465 310 4000 1 7 5 20,874 8945 42854 290 2000 1 7 5 31489 8887 28223 330 2000 3.5 7 5 19581 8840 45145 330 8000 1 7 5 20540 8411 40951 340 4000 3 15 5 19,554 8377 42840 330 8000 1 11 5 14736 8355 56697 330 2000 3.5 4 5 16346 7900 48331 330 2000 3.5 11 5 15981 7659 47928 330 8000 1 15 5 17368 7564 43549 330 2500 3 7 5 13372 7478 55922 330 2000 4 7 5 13903 7285 52399 330 4000 3 11 5 18870 6827 36180 330 2000 4 4 5 12574 6585 52375 330 10000 1 11 5 25732 6574 25549 330 2500 3.5 11 5 10387 6344 61076 310 2000 3 11 5 16153 6192 38332 330 2000 5 11 5 12167 6003 49340 330 2000 6 11 5 10208 5122 50176 270 2000 1 7 5 16193 4692 28977

Example 3.3: Precursor for the preparation of multimetal _{oxide of} the composition Cu _0.499 Mo _0.499 Bi _0.002 O _d (impregnation of Cu _0.5 Mo _0.5 O ₂ with 0.48 wt .-% bismuth):

The Fraction between 500 and 1000 microns from Example A3 was with aqueous bismuth nitrate solution (containing 4.8 mg Bi / 1 g fraction A3) on a shaker in a Porcelain bowl soaked. Subsequently, the Sample dried at 80 ° C under air, to 500 to 100 microns classified.

The following results were obtained in the reaction of o-xylene. An XRD analysis confirmed the presence of a Cu molybdate with the CuMoO ₄ structure (medium-pressure modification, index card 01-085-1530 of the ICDD PDF-2 Index, Release 2006) on an expansion sample of the catalyst. reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-Tolylaldehyde [° C] [h ^-1 ] [%] [%] [%] [%] [%] [%] 350 2000 1 11 5 69249 20,306 29324 360 4000 1 11 5 52727 18627 35328 350 2500 1 7 5 19872 18298 92077 340 2000 1 7 5 44185 16856 38148 350 1500 1 7 5 64122 16791 26186 350 2000 1 7 5 44492 15644 35162 340 1500 1 7 5 38815 15297 39411 340 2000 1 11 5 35079 14642 41740 350 4000 1 11 5 27362 14305 52281 340 2000 1 15 5 43718 14041 32117 330 2000 1 7 5 38734 13648 35237 340 1750 1 7 5 35452 13378 37735 330 2000 1 15 5 41839 12870 30760 340 2000 1 7 10 38235 12659 33109 360 8000 1 11 5 21698 12001 55312 330 2000 1 11 5 34490 11688 33887 340 2250 1 7 5 32504 10878 33468 340 2500 1 7 5 22132 10475 47330 340 4000 1 7 5 15135 9879 65272 340 4000 1 11 5 21376 9672 45249 330 1500 1 7 5 24144 9292 38487 330 4000 1 7 5 16618 7702 46345 350 8000 1 11 5 18961 7676 40482 330 4000 1 15 5 20292 6943 34213 360 4000 3 15 5 18813 6694 35579 330 4000 1 11 5 12967 6689 51588 340 2000 3 15 5 12450 5856 47038 330 2000 2 7 5 14051 5582 39728 330 2500 1 7 5 19517 5349 27407 310 2000 1 7 5 14726 5147 34955 350 4000 3 15 5 20496 4927 24038 340 8000 1 11 5 10902 4909 45027 350 4000 3 11 5 11549 4675 40477 340 8000 1 7 5 14836 4568 30787 330 2000 3 11 5 10993 4505 40982 340 2000 3 7 5 9739 4353 44701 330 2000 3 7 5 9795 4154 42408 330 8000 1 7 5 14,656 3770 25722 330 8000 1 15 5 13280 3350 25229 330 8000 1 11 5 14145 3258 23030 340 4000 3 15 5 12193 3022 24784 310 4000 1 7 5 8139 2994 36791 330 10000 1 11 5 16471 2,756 16733 330 10000 1 15 5 18764 2623 13978 290 2000 1 7 5 13094 2205 16840 310 8000 1 7 5 24161 1124 4653

Example 3.4 (ex 6): Precursor for the preparation of multimetal _{oxide of} the composition Cu _0.548 Mo _0.448 P _0.004 O _d (impregnation of Cu _0.55 Mo _0.45 O _1.9 with 0.1 wt% phosphorus):

The Fraction between 500 and 1000 microns from Example D2 was with aqueous phosphoric acid (containing 1.1 mg P / 1 g fraction D2) on a shaker in a porcelain dish soaked. Subsequently, the sample was at 80 ° C dried under air, classified to 500 to 1000 microns.

The following results were obtained in the reaction of o-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [h ^-1 ] [%] [%] [%] [%] [%] [%] 330 2000 3 11 5 60371 15453 25597 330 2000 3 7 5 44477 13501 30355 330 2000 1 11 5 72391 12189 16837 330 2000 1 15 5 76657 11669 15223 330 1500 3 7 5 13786 11405 82726 330 2500 3 11 5 43484 11203 25764 330 2500 3 7 5 35862 11059 30837 310 2000 1 7 5 70.052 10777 15,385 300 2000 1 7 5 45222 10574 23382 330 2750 3 7 5 32,900 10282 31252 330 2500 3 15 5 34308 9328 27190 330 2000 3.5 7 5 26409 8923 33789 340 2000 1 7 5 88425 8840 9998 290 2000 1 7 5 22434 8327 37115 330 2000 1 7 5 98163 3459 3523

Example 3.5: Precursor for the preparation of multimetal _oxide of composition Cu _0.4987 Mo _0.4987 Nb _0.0026 O _d (impregnation of Cu _0.5 Mo _0.5 O ₂ with 0.215 wt .-% niobium):

The Fraction between 500 and 1000 microns from Example A2 was with aqueous niobium ammonium oxalate solution (containing 2.15 mg Nb / 1 g fraction A2) on a shaker in a Porcelain bowl soaked. Subsequently, the Sample dried at 80 ° C under air, to 500 to 1000 microns classified.

The following results were obtained in the reaction of o.-xylene: reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 360 4000 1 11 5 51946 19675 37877 350 2000 1 11 5 77760 18952 24373 350 2500 1 7 5 34963 17812 50944 340 2000 1 11 5 54743 17,504 31975 350 4000 1 11 5 30945 15254 49294 340 2000 1 7 5 47818 14953 31269 350 1500 1 7 5 72394 14940 20637 350 2000 1 7 5 57429 14384 25048 340 1750 1 7 5 35518 14339 40371 340 2000 1 11 5 51179 14307 27955 340 2000 1 15 5 51487 13765 26735 340 1500 1 7 5 45454 13557 29826 330 2000 1 11 5 44186 13507 30567 340 2000 1 7 10 44660 13370 29937 330 2000 1 15 5 40351 13213 32745 330 2000 1 7 5 37838 12795 33815 360 8000 1 11 5 15531 12730 81964 340 2250 1 7 5 38389 11629 30292 340 4000 1 11 5 20594 10884 52849 340 1500 1 7 5 24024 10555 43935 340 4000 1 7 5 22442 10355 46143 340 2500 1 7 5 42216 9423 22322 350 8000 1 11 5 17852 8450 47330 330 4000 1 15 5 16589 8362 50406 360 4000 3 15 5 15230 8018 52645 330 4000 1 11 5 25694 7523 29278 330 4000 1 7 5 13740 7053 51333 340 2000 3 15 5 16833 6453 38333 310 2000 1 7 5 16713 6206 37131 340 1500 3 7 5 26,100 5647 21636 330 2000 2 7 5 40269 5632 13985 350 4000 3 15 5 19388 5592 28840 350 4000 3 11 5 10684 5262 49254 330 2000 3 11 5 10766 5098 47355 340 8000 1 11 5 20920 5057 24174 340 8000 1 7 5 21576 4844 22450 340 2000 3 7 5 11838 4794 40499 340 2000 2 7 5 9956 4325 43441 330 2000 3 7 5 11189 4266 38125 330 8000 1 15 5 16918 3963 23423 340 2500 3 7 5 9148 3932 42976 300 2000 1 7 5 12272 3930 32021 340 4000 3 15 5 13910 3570 25663 330 8000 1 7 5 12406 3551 28625 310 4000 1 7 5 12040 3496 29036 330 10000 1 15 5 18172 3139 17274

Example 3.6: Precursor for the preparation of multimetal _oxide of composition Cu _0.3998 Mo _0.5997 Cs _0.0005 O _d (impregnation of Cu _0.4 Mo _0.6 O _2.2 with 0.058 wt% cesium):

The Fraction between 500 and 1000 microns from Example E3 was with aqueous cesium nitrate solution (containing 0.58 mg Cs / 1 g fraction E3) on a shaker in a Porcelain bowl soaked. Subsequently, the Sample dried at 80 ° C under air, to 500 to 1000 microns classified.

The following results were obtained in the reaction of o-xylene. An XRD analysis of an exhaust sample of the catalyst revealed the presence of a mixture of a Cu molybdate with the CuMoO ₄ structure (main product, medium-pressure modification, index card 01-085-1530 of the ICDD PDF 2 file, release 2006) and MoO ₃ ( By-product, index card 00-005-0508 of the ICDD PDF-2 Index, Release 2006). reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 350 2000 1 11 5 10553 8,009 75899 340 2000 1 11 5 17526 7029 40107 330 2000 1 7 5 19530 6572 33651 330 2000 1 11 5 18696 5820 31132 310 2000 1 7 5 9486 4030 42490 330 3000 1 11 5 10845 3643 33592

Example 3.7: Precursor for the preparation of multimetal _{oxide of} the composition Cu _0.4998 Mo _0.4998 La _0.0004 O _d (impregnation of Cu _0.5 Mo _0.5 O ₂ with 0.052 wt% lanthanum):

The Fraction between 500 and 1000 microns from the example Al was with aqueous lanthanum nitrate solution (containing 0.52 mg La / 1 g fraction Al) on a shaker in a Porcelain bowl soaked. Subsequently, the Sample dried at 80 ° C under air, to 500 to 1000 microns classified.

The following results were obtained in the reaction of o-xylene. An XRD analysis confirmed the presence of a Cu molybdate with the CuMoO ₄ structure (medium-pressure modification, index card 01-085-1530 of the ICDD PDF-2 Index, Release 2006) on an expansion sample of the catalyst. reactor GHSV o-xylene oxygen water sales Yield o-tolualdehyde Selectivity o-tolualdehyde [° C] [H-1] [%] [%] [%] [%] [%] [%] 350 2000 1 11 5 63773 18204 28546 360 4000 1 11 5 37776 17987 47615 340 2000 1 7 5 37888 14882 39279 340 2000 1 11 5 35185 14826 42137 350 1500 1 7 5 49550 13956 28164 350 2000 1 7 5 40354 13894 34432 330 2000 1 7 5 38683 13598 35152 350 2500 1 7 5 24398 13079 53605 350 4000 1 11 5 26619 12494 46937 340 2000 1 15 5 29776 12479 41910 340 1500 1 7 5 30929 12274 39685 340 2000 1 7 10 26483 11768 44435 330 2000 1 15 5 30,761 11,306 36752 340 1750 1 7 5 25696 10784 41968 330 2000 1 11 5 27866 10629 38144 360 8000 1 11 5 15171 10627 70045 340 4000 1 11 5 11697 8841 75580 340 2250 1 7 5 28757 8665 30133 340 2500 1 7 5 21679 8449 38975 340 4000 1 7 5 10888 8242 75696 330 1500 1 7 5 19123 7274 38038 330 4000 1 7 5 19852 7226 36401 350 8000 1 11 5 8716 7034 80.700 310 2000 1 7 5 16967 6652 39202 330 4000 1 15 5 24964 5819 23311 340 2000 3 15 5 14952 5636 37690 330 4000 1 11 5 18074 5495 30402 330 2000 2 7 5 42008 5299 12614 330 2000 3 11 5 10758 4879 45357 340 2000 2 7 5 14837 3517 23706 330 2000 3 7 5 16003 3469 21678 330 8000 1 7 5 12420 3418 27518 310 4000 1 7 5 10881 3000 27570 340 4000 3 15 5 13991 2921 20875 330 8000 1 15 5 12024 2878 23938 330 8000 1 11 5 9330 2701 28952 330 10000 1 15 5 21338 2165 10144 330 10000 1 11 5 17341 2159 12449

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0256352 [0005]
• WO 00/27753 [0006]
• EP 0756894 [0007]
• - NL 7209921 [0008]
• - US 4140722 [0009]
• US 5,324,402 [0010]
• - DE 10122027 A [0036, 0065]
• JP 8-57319A [0038]
• - EP 1254707 A [0038]
• - DE 19809477 [0066]

Claims (13)

Process for the partial oxidation of alkylaromatics in the gas phase using a catalyst whose catalytically active composition contains a multimetal oxide of the general formula I. Cu _a Mo _b M _c O _d · eH ₂ O (I) wherein M is at least one of Ti, Zr, V, Nb, Ta, Cr, W, Re, Mn, Fe, Co, Ni, Ag, Zn, Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, B, Al, Ga, Si, Sn, Pb, P, Sb, Bi, La, Ce, selected element, a / b has a value of 0.1 to 10, c has a value of less than 0.1 has, a + b + c is 1, d is a number determined by the valency and frequency of the non-oxygen elements in formula I, e has a value of 0 to 20. The method of claim 1, wherein a / b is a value from 0.2 to 5 has. The method of claim 2, wherein a / b is a value from .33 to 3 has. Method according to one of the preceding claims, in which c has a value of 0.001 to 0.05. Method according to one of the preceding claims, in which M for at least one among V, Nb, Cr, Re, Fe, Co, Ag, Zn, B, Al, Ga, Pb, P, Sb, Bi, La, Ce Element stands. The method of any one of the preceding claims wherein the multimetal oxide comprises crystallites having the structural type of one or more of the copper molybdate listed below: Cu ₄ Mo ₆ O ₂₀ Cu ₄ Mo ₅ O ₁₇ Cu ₆ Mo ₅ O ₁₈ Cu ₆ Mo ₄ O ₁₅ CuMoO ₄ (medium pressure modification) CuMoO ₄ (high pressure modification) Cu _3.85 Mo ₃ O ₁₂ Cu ₃ Mo ₂ O ₉ Cu _1.49 Mo ₈ O ₂₄ Method according to one of the preceding claims, wherein the multimetal oxide is a mixture of crystalline and / or amorphous phases of the compositions Cu _w Mo _x M _y O _z , Cu _w Mo _x O _z , Cu _w M _y O _z , Mo _x M _y O _z , Cu _w O _z , Mo _x O _z and / or M _y O _z , wherein w, x, y, z are each independently selected so that the sum composition of the mixture of formula I corresponds. Method according to one of the preceding claims, wherein the alkylaromatic is toluene, o-xylene, m-xylene and p-xylene is selected. Process according to Claim 8, for the preparation of o-tolualdehyde from o-xylene. Method according to one of the preceding claims, wherein the alkylaromatic on a catalyst whose catalytic active mass contains a multimetal oxide of the formula I, converts to an intermediate reaction mixture and the intermediate reaction mixture or fractions thereof one further converts at least one further catalyst. The method of claim 10, wherein the catalytic active mass of the further catalyst titanium dioxide and vanadium pentoxide includes. A gas phase oxidation catalyst comprising a catalytically active composition consisting essentially of a metal mixed oxide of the general formula I. Cu _a Mo _b M _c O _d · eH ₂ O (I) wherein M, a, b, c, d and e are as defined in claim 1. A gas phase oxidation catalyst according to claim 12, wherein the catalytically active material is an inert carrier is applied.