JP5517407B2 - Method for producing multi-metal oxide material - Google Patents

Description

The present invention provides the following general stoichiometry I:
^{_{Mo 1 V a M 1 b M}} 2 c M 3 d M 4 e O n (I)
[Wherein M ¹ = at least one element selected from the group consisting of Al, Ga, In, Ge, Sn, Pb, As, Bi, Se, Te and Sb;
M ² = at least one element selected from the group consisting of Sc, Y, La, Ti, Zr, Hf, Nb, Ta, Cr, W, Mn, Fe, Co, Ni, Zn, Cd and lanthanoids;
M ³ = At least one element selected from the group consisting of Re, Ru, Rh, Pd, Os, Ir, Pt, Cu, Ag, Au;
M ⁴ = at least one element selected from the group consisting of Li, Na, K, Rb, Cr, Be, Mg, Ca, Sr, Ba, NH ₄ and Tl;
a = 0.01-1;
b = ≧ 0-1;
c = ≧ 0-1;
d = ≧ 0 to 0.5;
e = ≧ 0 to 0.5 and n = the number determined by the valence and frequency of appearance of elements other than oxygen in (I)]. And
Here, the mixture G of the raw material of the elemental component of the multimetal oxide material M is subjected to a hydrothermal treatment, whereby a newly formed solid is separated.

Multi-metal oxide materials M of general stoichiometry I and processes for their preparation are known (EP-A 318295, EP-A 512846, EP-A 767164, EP-A 865809, EP-A 529853, EP-A 608838, EP-A 962533, DE -A10248584, DE-A101199933, DE-A10118814, DE-A10029338, DE-A10359027, DE-A10321398, EP-A1407819, Applied Catalysis A: General 194-195 (2000) pages 479-485; Pages 135-143; Chem. Commun. 1999, pages 517-518; termed.26 (2) (2000), pages 137-144; Topics Cat.15 (2001) pages 153-160; Catalysis Surveys from Japan6 (1/2) (2992) 33-44 and Appl. Catal.A: General 251 (2003) See pages 411-424).

  Also, from the above prior art, such multi-metal oxide materials M are of saturated and unsaturated hydrocarbons, such as alcohols and aldehydes (for example having 3 to 8, in particular having 2 or 3 and / or 4 carbon atoms). For hybrid catalyzed partial gas phase oxidation and for hybrid catalyzed partial gas phase ammoxidation (which is substantially different from direct partial gas phase oxidation through the presence of additional ammonia) It is known to be suitable as an active substance for the catalyst. The resulting partial oxidation products are in particular α, β-monoethylenically unsaturated aldehydes (eg acrolein and metaacrolein) and α, β-monoethylenically unsaturated carboxylic acids (eg acrylic acid and methacrylic acid). And its nitriles (eg, acrylonitrile and methacrylonitrile). The target compounds acrolein, acrylic acid and / or acrylonitrile can be obtained, for example, from the hydrocarbon propane and / or propene by the method described. Acrolein may also itself be a starting material for the production of the latter two compounds. These target compounds form, for example, important intermediates that can be used as adhesives, for example used for the production of polymers.

  In a corresponding manner, methacrolein and methacrylic acid can be obtained from isobutane and isobutene. Methacrolein may also be a starting material for the production of methacrylic acid.

  Furthermore, it is recognized from the prior art that the multi-metal oxide material M is different from each other and appears mainly in the two crystalline phases referred to in the writing as “i-phase” and “k-phase”. Known.

  Because of its characteristics and its crystalline structure characteristics, the associated X-ray diffractogram is used as a fingerprint for each crystalline phase.

  The X-ray diffraction diagram of the crystalline i-phase includes the following X-ray diffraction pattern RMi reproduced in the shape of the lattice spacing d [Å] independently of the wavelength of the X-ray used.

d [Å]
3.06 ± 0.2
3.17 ± 0.2
3.28 ± 0.2
3.99 ± 0.2
9.82 ± 0.4
11.24 ± 0.4
13.28 ± 0.5
The X-ray diffraction diagram of the crystalline k-phase includes the following X-ray diffraction pattern RMi reproduced in the shape of the lattice spacing d [Å] independently of the X-ray wavelength used.

d [Å]
4.02 ± 0.2
3.16 ± 0.2
2.48 ± 0.2
2.01 ± 0.2
1.82 ± 0.1
The i-phase and the k-phase are similar to each other, except that the k-phase diffractogram usually has no reflection of d ≧ 4.2４. Usually, the k-phase also does not contain reflections in the range of 3.8Å ≧ d ≧ 3.35Å. Furthermore, the k-phase in principle does not contain reflections in the range 2.95Å ≧ d ≧ 2.68Å.

  Furthermore, the catalytic effect (activity, selectivity of the target product structure) of the multi-metal oxide material having an i-phase structure should in principle be superior to that of other (eg k-phase) structures. Known from the above prior art.

  However, it is known from the prior art that it is very difficult to produce an i-phase structured multi-metal oxide material M.

  Thus, in principle, a solid solution system is obtained, which has only a certain i-phase part (in addition to the k-phase, for example), from which a suitable liquid is obtained in view of optimum catalyst performance. The i-phase portion is isolated by washing away the other phases (eg k-phase). (For example, WO02 / 06199, JP-A7-232011, DE-A10254279 and EP-A1407819).

  The production of a multi-metal oxide material of general stoichiometry I is generally achieved by a process in which an intimate dry mixture is produced from a starting material (raw material) containing its elemental components and the dry mixture is subjected to a heat treatment at high temperature. To be achieved.

  When a raw material mixture of elemental constituents of the multimetal oxide material M is subjected to hydrothermal treatment to separate a newly formed solid, a high i-phase portion up to an exclusive i-phase is obtained in principle. (See US-A2003 / 0187299A1, DE-A10029338, EP-A1270068, EP-A1346766 and EP-A1407819).

  In accordance with the prior art statement, suitable raw materials for elemental components are almost all possible compounds containing elemental components in chemically bonded form.

However, a disadvantage of the hydrothermal production process carried out in the present method is that the reproducibility is not completely satisfied, especially in the case of industrial production. For example, the i-phase portion obtained in such production varies within a relatively wide range of average values over repeated production. Often this average value is in the relatively lower i-phase part. Furthermore, the catalytic performance of products obtained directly with hydrothermal heat is often unsatisfactory and, in principle, requires a subsequent heat treatment to improve it.
Accordingly, it was an object of the present invention to provide a method for hydrothermal production of multi-metal oxide material M of general stoichiometry I which has an improved method with respect to the above mentioned drawbacks.

Thus, the following general stoichiometry I:
^{_{Mo 1 V a M 1 b M}} 2 c M 3 d M 4 e O n (I)
[Wherein M ¹ = Al (+3), Ga (+3), In (+3), Ge (+4), Sn (+4), Pb (+4), As (+5), Bi (+5), Se (+6 ), Te (+6) and Sb (+5) at least one element selected from the group consisting of;
M ² = Sc (+3), Y (+3), La (+3), Ti (+4), Zr (+4), Hf (+4), Nb (+5), Ta (+5), Cr (+5), W ( +6), Mn (+7), Fe (+3), Co (+3), Ni (+3), Zn (+2), Cd (+2) and lanthanoids (Ce (+4), Pr (+3), Nd (+3) , Pm (+3), Sm (+3), Eu (+3), Gd (+3), Tb (+4), Dy (+3), Ho (+3), Er (+3), Tm (+3), Yb (+3) And at least one element selected from the group consisting of Lu (+3));
M ³ = Re (+7), Ru (+8), Rh (+8), Pd (+8), Os (+8), Ir (+8+), Pt (+8), Cu (+2), Ag (+1), Au ( +1) at least one element selected from the group consisting of;
M ⁴ = Li (+1), Na (+1), K (+1), Rb (+1), Cs (+1), Be (+2), Mg (+2), Ca (+2), Ir (+2), Ba ( +2), at least one element selected from the group consisting of NH ₄ (+1) and Tl (+1);
a = 0.01-1 (preferably 0.01-0.5);
b = ≧ 0 to 1 (preferably> 0 to 0.5);
c = ≧ 0 to 1 (preferably> 0 to 0.5);
d = ≧ 0 to 0.5 (preferably ≧ 0 to 0.1);
e = ≧ 0 to 0.5 (preferably ≧ 0 to 0.1 or 0) and n = number determined by the valence and frequency of occurrence of elements other than oxygen in (I)] A method for producing a multi-metal oxide material M was invented. Here, a mixture G of raw materials of elemental constituents of the multi-metal oxide material M was subjected to hydrothermal treatment, and a newly formed solid was separated, The elemental component of the multimetal oxide material M and the elemental component of water (O, H, OH), the elemental component of the multimetal oxide material M itself of the element shape, and the elemental composition of the multimetal oxide material M Ammonium salts containing components (eg, elemental component oxides, hydrated oxides, oxyacids, hydroxides, hydroxide oxides, elemental component metal elements, and ammonium metavanadate or ammonium heptamolybdate) Compound) only Raw materials exclusively selected from the group consisting more is a mixture NH ₄ and mixture NH 4 _/ Mo molar ratio part of the raw material of the MV ≦ 0.5 and at least the elemental constituents of Mo contained in the G contained in G Is an oxidation number lower than the maximum oxidation number of each elemental component (this is a number that is displayed in parentheses after the independently listed elements M ¹ , M ² , M ³ and M ⁴ and has a positive sign) Is used as a raw material for the elemental constituents of the multi-metal oxide material M on the condition that the constituent elements contained in these raw materials are included.

  It is preferred according to the invention if at least part of the raw material of the elemental constituent V (present in the mixture G) contains vanadium with an oxidation number <+5 (for example +4 or +3 or +2 or 0).

  Hydrothermal production of multimetal oxide actives is known to those skilled in the art (eg, Applied Catalysis A: 194-195 (2000) 479-485; Kinetics and Catalysis; Vol. 40, No. 3, 1999, pp 401-404; Chem. Commun., 1999, 517-518; see also JP-A6 / 227819 and JP-A2000 / 26123).

  In the present description, the operating method according to the invention is preferably carried out at a temperature of> 100 ° C. to 600 ° C., in the presence of water vapor at superatmospheric pressure, in a vessel under superatmospheric pressure (autoclave), in the desired manner. It is understood in the sense of a heat treatment of a preferably intimate mixture G of the raw materials of the elemental constituents of the multimetal oxide material M. The pressure range is typically extended to (> 1 bar) up to 500 bar, preferably up to 250. According to the invention, temperatures above 600 ° C. and water vapor pressures above 500 bar can of course also be used, but are not very suitable for the purpose of application technology.

  Particularly advantageously, the hydrothermal treatment according to the invention is achieved under conditions in which water vapor and a liquid aqueous phase coexist. This is possible in the temperature range> 100-374.15 ° C. (critical temperature of water) using corresponding pressures. Suitably the amount of water is such that the liquid aqueous phase can dissolve the total amount of elemental constituent starting compounds in the suspension and / or solution.

  However, according to the invention, a hydrothermal process is also possible in which a preferably intimate mixture G of elemental constituent starting compounds completely absorbs the amount of liquid water that is in equilibrium with water vapor.

  According to the invention, the hydrothermal treatment according to the invention is conveniently achieved at temperatures> 100 ° C. to 300 ° C., preferably 120 ° C. or 150 ° C. to 250 ° C. (eg 160 ° C. to 180 ° C.).

  Based on the total amount of water and the mixture G (or the raw material of the elemental constituents of the multimetal oxide material M contained therein), the latter weight ratio in the autoclave is in principle at least 1% by weight according to the invention. is there. In general, the above-mentioned weight ratio should not exceed 90% by weight. The weight ratio is preferably 5 to 60 or 10 to 50% by weight, particularly preferably 20 to or 30 to 50% by weight.

Apart from the raw materials according to the invention of the multi-metal oxide material M and the elemental constituents of water, preferably no further substances are required for the hydrothermal operating method according to the invention. The weight ratio of further substances should usually be ≦ 10% by weight, conveniently ≦ 5% by weight and more preferably ≦ 3% by weight, based on the mixture G. For example, all substances described in DE-A1003338 and EP-A1407819 other than H ₂ O ₂ (taking into account preferred redox conditions) are suitable as possible foreign substances of this type.

  The hydrothermal treatment according to the invention can be carried out with (preferred) or without stirring.

  Conveniently, in the process according to the invention, the molar ratio MV is ≦ 0.3, particularly preferably ≦ 0.1 and very particularly preferably 0.

  Based on the total amount of raw materials of the elemental constituents contained in the mixture G and the total molar amount of V contained in these raw materials, it is preferably contained in these raw materials in the process according to the invention, preferably at least 5 mol% or at least 10 mol%, preferably at least 20 mol% or at least 30 mol%, very particularly preferably at least 40 mol% or 50 mol% and most preferably at least 60 mol% or at least 70 mol% or 80 mol% or at least 90 mol% % Or more (particularly advantageously total) V is included as vanadium with an oxidation number <+5.

  The mathematical average oxidation number of V obtained by averaging the total molar amount of V of the vanadium raw material contained in the mixture G is preferably +3.5 to +4.5, particularly preferably +3.8 to +4.2 and particularly preferably +4. is there.

  Very generally (especially when V is included in at least part of its raw material at its maximum oxidation number), the composition of the mixture G of the process according to the invention is preferably the raw material for the mixture G Is selected with respect to the oxidation number of the elemental constituents contained in the mixture G, so that all elemental constituents other than V (+5) not included in the maximum oxidation number in the mixture G raw material (including V (<+ 5)) are maximized respectively. When changed to the oxidation number (in the case of V, the second highest oxidation number +4), the available reduction capacity is that the average oxidation number of V contained in the raw material of the mixture G is 3.5-4. .5, particularly preferably from 3.8 to 4.2, very particularly preferably to a value of 4.

  If the hydrothermal treatment according to the present invention is achieved under an oxidizing atmosphere containing oxygen molecules (for example under static and sealed air), the above-mentioned reducing ability may be considerably higher.

  In general, the conditions of the hydrothermal treatment according to the present invention are preferably selected so that the reducing capacity is actually implemented in the manner described during hydrothermal treatment.

For the determination of the oxidation number of V or another elemental component in the raw material, essentially known laws are applied according to the fact that the oxidation number of an element in a chemical compound is obtained as follows.
1. The oxidation number of atoms in free elements is zero.
2. The oxidation number of a single atom ion is equal to its charge.
3. In a covalently bonded compound of known structure, when the bonding electron pair is completely distributed to more electronegative atoms, the oxidation number corresponds to the charge that each atom contains. In the case of an electron pair between two identical atoms, each atom receives one electron.
(Grundgen der allgemeinen und organischen Chemie [Principles of general and organic chemistry], Verlag Sauerlander, Aarau, Diesterweig.
Accordingly, suitable raw materials for element V for the process according to the invention are in particular vanadium such as VO ₂ , V ₂ O ₃ , V ₆ O ₁₃ , V ₃ O ₇ , V ₄ O ₉ and VO. The same applies to oxides, elemental vanadium and compounds such as V ₂ O ₅ and ammonium metavanadate, taking into account the quantity limits according to the invention.

Ingredients for elemental Mo suitable according to the present invention include, for example, ammonium heptamolybdate and its hydration in view of oxides of molybdenum such as MoO ₃ and MoO ₂ , elemental Mo and the amount restrictions according to the present invention. The same applies to compounds such as products.

According to the present invention, suitable raw materials for elemental tellurium are, for example, tellurium oxides such as TeO ₂ , metal tellurium and telluric acid such as orthotelluric acid H ₆ TeO ₆ .

Antimony starting compounds that are advantageous according to the invention are, for example, antimony oxides such as Sb ₂ O ₃ , element Sb and antimonic acid such as HSb (OH) ₆ .

A suitable niobium source in accordance with the present invention is a niobium oxide such as Nb ₂ O ₅ or the element Nb.

A convenient bismuth source in accordance with the present invention is Bi ₂ O ₃ . A convenient gold source is gold hydroxide. Further convenient starting compounds for the process according to the invention are, for example, silver oxide, copper hydroxide, copper oxide, alkali and alkaline earth metal oxides and hydroxides, scandium oxide, iridium oxide, zinc oxide. , Ga ₂ O, Ga ₂ O _{3 and the} like. Of course, one or more elemental constituents are included and, if appropriate, mixed oxides obtained by hydrothermal methods, for example hydrothermal methods according to the invention, are also suitable as raw materials for elemental constituents. Furthermore, suitable elemental constituent materials in accordance with the present invention are described in the cited prior art publications.

The hydrothermal treatment itself according to the present invention generally lasts minutes or hours to days. A period of 48 hours is typical. If the autoclave used for hydrothermal treatment is internally coated with Teflon, it is suitable for the purpose of applied technology. Prior to the hydrothermal treatment, the autoclave contains an aqueous mixture optionally contained and can be expelled conveniently. Thereafter, the autoclave before the temperature rises can preferably be filled with an inert gas (N _2, the He, noble gases such as Ne and / or argon). Both measures can be excluded, but this is not very convenient. In order to create convenient inert conditions, the aqueous mixture can of course be flushed with an inert gas instead of or before the hydrothermal treatment according to the invention. Even before the hydrothermal treatment, the above-mentioned inert gas can also be used appropriately for the purpose of applied technology in order to establish a superatmospheric pressure in the autoclave.

  After completion of the hydrothermal treatment, the autoclave can be quenched at room temperature or can be slowly returned to room temperature, for example over a relatively long period of time (eg, left to stand).

  An important aspect according to the present invention is that the solid that is newly formed in the hydrothermal treatment according to the present invention and separated after completion of the hydrothermal treatment usually has a high i-phase part or exclusively i-phase. A multi-metal oxide M that is obtained with improved reproducibility according to the present invention.

  Further, the importance according to the present invention is that the multimetal oxide M obtained by the method according to the present invention exhibits a desired catalytic activity even when the heat treatment after the hydrothermal treatment is not used.

  Of course, the multimetal oxide M obtained according to the invention can be conveniently subjected to an additional thermal workup before it is used as an active material for the hybrid catalyzed process described at the outset. . This thermal aftertreatment can be carried out at a temperature of 200 to 1200 ° C., preferably 350 to 700 ° C., often 400 to 650 ° C., often 400 to 600 ° C.

  In principle, it can be achieved in an oxidizing, reducing or inert (preferred according to the invention) atmosphere. Suitable oxidizing atmospheres are, for example, air, oxygen molecule rich air or oxygen depleted air.

  Preferably, the heat treatment is performed under an inert atmosphere, for example, with nitrogen molecules and / or noble gases (He, Ar and / or Ne) (in this specification, the inert atmosphere always has a content of oxygen molecules usually ≦ 5 volumes). %, Preferably ≦ 3% by volume, particularly preferably ≦ 1% by volume or ≦ 0.1% by volume, most preferably 0% by volume). Of course, thermal aftertreatment can also be achieved under reduced pressure.

  In general, the thermal aftertreatment may last for 24 hours or longer. Thermal post-treatment is preferably first achieved at temperatures of 150 ° C. to 400 ° C. or 250 ° C. to 350 ° C. under oxidation (oxygen-containing atmosphere) (eg, under air). Thereafter, the heat treatment is suitably continued under inert gas at a temperature of 350 ° C. to 700 ° C. or 400 ° C. to 650 ° C. or 400 ° C. to 600 ° C. Of course, the thermal post-treatment of the hydrothermally generated multimetal oxide M is also the same as the hydrothermally generated multimetal oxide M is first pelletized and then subjected to thermal post-treatment, followed by Can be achieved in such a way as to be converted into a chip.

  However, if the multi-metal oxide M obtained in the hydrothermal method according to the invention is converted into chips for its thermal aftertreatment, it is appropriate for the purpose of applied technology.

  Furthermore, both the multi-metal oxide material M obtained according to the invention by the hydrothermal method and the subsequent or successor multi-metal oxide material which has been heat-treated as described are for example DE-A 10254279 and EP-A 140 7819. Can be further processed in a convenient manner by washing them with a suitable liquid as described in. Suitable such liquids include, for example, organic acids and aqueous solutions thereof (eg, oxalic acid, formic acid, acetic acid, citric acid and tartaric acid) and inorganic acids and aqueous solutions thereof (sulfuric acid, perchloric acid, hydrochloric acid, nitric acid, boric acid and (Or telluric acid), alcohols, alcoholic solutions of the above-mentioned acids or hydrogen peroxide and aqueous solutions thereof. Of course, mixtures of the above-mentioned cleaning liquids can also be used for cleaning. Furthermore, JP-A7-231201 or DE-A10321398 also discloses suitable cleaning methods. In such washing, pure i-phase (or increased i-phase portion) usually remains in the washed state and usually also has further improved catalytic performance.

  Intimate mixing of the starting components of the elemental constituents for the hydrothermal treatment of the mixture G can be achieved in dry or wet form. If achieved in the dry state, the starting compound is suitably used in the form of a finely divided powder. However, intimate mixing is preferably achieved in wet aqueous form. The starting compounds are preferably mixed with one another in the form of an aqueous solution (optionally accompanied by a small amount of complexing agent) and / or a finely divided suspension.

  Above and above the reflection already described at the beginning, the multi-metal oxide material M obtained hydrothermally according to the invention or the subsequent substance obtained by thermal post-treatment and / or cleaning carried out as described (or X-ray diffraction patterns RMi of (subsequent materials) often have additional characteristic reflection intensities (depending on the elements contained and the crystal geometry (eg, acicular or table shape)).

Based on the reflection intensity represented by the lattice spacing d [Å] = 3.99 ± 0.2, these (relative) reflection intensities I (%) are as follows:
d [Å] I (%)
3.06 ± 0.2 (preferably ± 0.1) 5 to 65
3.17 ± 0.2 (preferably ± 0.1) 5 to 65
3.28 ± 0.2 (preferably ± 0.1) 15-130, often 15-95
3.99 ± 0.2 (preferably ± 0.1) 100
9.82 ± 0.4 (preferably ± 0.2) 1-50, often 1-30
11.24 ± 0.4 (preferably ± 0.2) 1-45, often 1-30
13.28 ± 0.5 (preferably ± 0.3) 1-35, often 1-15
In addition to the above, the following reflection, which is a particularly characteristic reflection that is further reproduced in the shape of the lattice spacing d [Å] independently of the X-ray wavelength used, is also often detected by the X-ray diffraction pattern RMi described above. Is possible.

d [Å]
8.19 ± 0.3 (preferably ± 0.15)
3.51 ± 0.2 (preferably ± 0.1)
3.42 ± 0.2 (preferably ± 0.1)
3.34 ± 0.2 (preferably ± 0.1)
2.94 ± 0.2 (preferably ± 0.1)
2.86 ± 0.2 (preferably ± 0.1)
Based on the intensity of the reflection expressed as the lattice spacing d [Å] = 3.99 ± 0.2, the (relative) intensity I (%) of the reflection is often as follows:
d [Å] I (%)
8.19 ± 0.3 (or ± 0.15) 0-25
3.51 ± 0.2 (or ± 0.1) 2-50
3.42 ± 0.2 (or ± 0.1) 5 to 75
3.34 ± 0.2 (or ± 0.1) 5-80
2.94 ± 0.2 (or ± 0.1) 5-55
2.86 ± 0.2 (or ± 0.1) 5-60
Often, the following reflections also supplement the X-ray diffraction pattern RMi described above:
d [Å]
2.54 ± 0.2 (preferably ± 0.1)
2.01 ± 0.2 (preferably ± 0.1)
For these reflections, the (relative) reflection intensity with the same criteria as above is often as follows:
d [Å] I (%)
2.54 ± 0.2 (or ± 0.1) 0.5-40
2.01 ± 0.2 (or ± 0.1) 5-60
In accordance with the present invention, a preferred X-ray diffraction pattern among the above-described X-ray diffraction patterns RMi (or multi-metal oxide materials or successors related to the patterns) has a lattice spacing d [Å] = 3.99 Reflection represented by ± 0.2 (or ± 0.1) or lattice spacing d [Å] = 3.28 ± 0.2 (or ± 0.1) is the strongest reflection (strongest) It has a strength of

  Furthermore, the preferred X-ray diffraction pattern RMi (or a multi-metal oxide material or successor related to the above pattern) is half the reflection d [Å] = 3.99 ± 0.2 (or ± 0.1). The total 2θ width at a height of ≦ 1 °, preferably ≦ 0.5 °. The 2θ full width at half height of the other reflections described is usually ≦ 3 °, preferably ≦ 1.5 °, particularly preferably ≦ 1 °.

All data in this specification relating to X-ray diffractograms is based on X-ray diffractograms generated using CuKα radiation (λ = 1.54178Å) as X-rays. (Siemens diffractometer Theta-Theta D-5000, tube voltage: 40 kV, tube current: 40 mA, aperture diameter V20 (variable), collimator V20 (variable), second monochromator aperture diameter (0.1 mm), detector aperture Diameter (0.6 mm), measurement interval (2θ): 0.02 °, measurement time per step: 2.4 s, detector: scintillation counter; in this specification, the definition of the reflection intensity of the X-ray diffraction diagram is DE− A19835247, DE-A10122027 and DE-A10051419 and DE-A10046672 are hereby incorporated by reference in this application; the definition of half height 2θ full width applies as well)
The X-ray wavelength λ used for diffraction and diffraction angle θ (here, the vertex of reflection in the 2θ plot is used as the position of reflection) is related to each other via the Bragg relationship as follows: .

2 sin θ = λ / d
Here, d is a lattice plane interval of a three-dimensional atomic arrangement related to each reflection.

Preferred multi-metal oxide materials of general stoichiometry I obtained according to the present invention (and their successors) are those to which:
M ¹ = at least one element selected from the group consisting of Sb, Bi, Se, and Te;
M ² = at least one element selected from the group consisting of Ti, Zr, Nb, Cr, W, Fe, Co, Ni and Zn;
At least one element selected from the group consisting of M ³ = Re, Pd and Pt;
M ⁴ = at least one element selected from the group consisting of Rb, Cs, Sr and Ba;
a = 0.01-1 (preferably 0.01-0.5);
b = ≧ 0 to 1 (preferably> 0 to 0.5);
c = ≧ 0 to 1 (preferably> 0 to 0.5);
d = ≧ 0 to 0.5 (preferably ≧ 0 to 0.1);
e = ≧ 0 to 0.5 (preferably ≧ 0 to 0.1 or 0) and n = a number determined by the valence and appearance frequency of elements other than oxygen in (I).

  Independent of the preferred range for the multi-metal oxide material M and other stoichiometric factors of the selected elemental composition, the multi-metal oxide material M (and its related successors) obtained according to the present invention A stoichiometric coefficient a of 0.05 to 0.5, particularly preferably 0.1 to 0.5 is preferred according to the invention.

  Independent of the preferred range for the multi-metal oxide material M and other stoichiometric coefficients of the selected elemental composition, the stoichiometric coefficient b is preferably> 0 or 0.01 to 0.5, in particular 0.1 to 0.5 or 0.4.

  Independent of the preferred range for the multi-metal oxide material M and other stoichiometric coefficients of the selected elemental composition, the stoichiometric coefficient c of the multi-metal oxide material M obtained according to the present invention is advantageous. Is from 0.01 to 0.5 and particularly preferably from 0.1 to 0.5 or 0.4. Independent of the preferred range due to other stoichiometric coefficients of the multi-metal oxide material M obtained according to the present invention, the chemistry that can be combined in this specification and all other preferred ranges of all selected elemental compositions. A very particularly preferred range for the stoichiometric coefficient c is in the range of 0.05 to 0.2.

  Independent of the preferred range for the multi-metal oxide material M and other stoichiometric coefficients of the selected elemental composition, the stoichiometric coefficient d of the multi-metal oxide material M obtained according to the invention is preferably > 0 or 0.00005 or 0.0005 to 0.5, particularly preferably 0.001 to 0.5, often 0.002 to 0.3 and often 0.005 or 0.01 to 0.1 .

  Independent of the preferred range for the multi-metal oxide material M and other stoichiometric coefficients of the selected elemental composition, the coefficient e can also be ≧ 0 to 0.1, conveniently 0.

Multi-metal oxide materials M obtained according to the invention and whose stoichiometric coefficients a, b, c and d are simultaneously in the following range are particularly advantageous:
a = 0.05-0.5;
b = 0.01-1 (or 0.01-0.5);
c = 0.01-1 (or 0.01-0.5);
d = 0.005-0.5; and e = ≧ 0-0.5
Multi-metal oxide materials M obtained according to the invention and whose stoichiometric coefficients a, b, c and d are simultaneously in the following range are particularly advantageous:
a = 0.1-0.5;
b = 0.1-0.5;
c = 0.1-0.5;
d = 0.001 to 0.5 or 0.001 to 0.3 or 0.001 to 0.1; and e = ≧ 0 to 0.2 or 0.1.
M ¹ is preferably Bi, Se, Te and / or Sb, very particularly preferably Te.

In particular, at least 50 mol% of the total amount of M ² is Nb, Ti, Zr, Cr, W, Fe, Co, Ni, Zn and / or Ta, very particularly preferably at least 50 mol% of the total amount of M ² or at least 75 mole%, or 100 mole% of the total amount of ^{M 2} is Nb, and at least one element, Ti, Zr, Cr, Ta , W, Fe, Co, in Ni and Zn or Nb and / or Ta In some cases, all of the above apply.

However, independently of the meaning of M ^2, even if M ³ is at least one element selected from at least Re, the group consisting of Pd or Pt also apply.

However, in particular at least 50 mol% of the total amount of ^{M 2,} or 75 mol% or 100 mol% is Nb, if at least one ^{element M 3} is selected Re, from the group consisting of Pd and Pt, above All of this also applies.

However, in particular at least 50 mol% or at least 75 mole%, or 100 mol% Nb of the total amount of ^{M 2,} and at least one element but is Co, Ni, Ta, W, Fe, and ^{M 3} is Re, All of the above apply when it is at least one element selected from the group consisting of Pd and Pt.

Very particularly preferably, M ¹ is Te, M ² is Nb, and at least one of the elements is Ni, Co, Fe, and M ³ is at least selected from the group consisting of Pd, Re and Pt In the case of one element, all statements regarding stoichiometric coefficients apply.

Convenient multimetal oxide materials M obtained according to the invention are those with e = 0 (and in particular all those mentioned above). If e> 0, M ⁴ is preferably Cs.

  Further, suitable stoichiometry I according to the present invention is that disclosed herein for the cited prior art stoichiometric (I) multi-metal oxide materials.

  The general stoichiometric I multi-metal oxide material obtained according to the invention by the hydrothermal method as described or the substances following the multi-metal oxide material (in principle they have a further stoichiometry I) are Catalytically for all partial gas phase oxidation and / or ammoxidation of itself (for example as powder or chips) or after being molded into, for example, saturated and unsaturated hydrocarbons or low aldehydes and / or alcohols It can be used as an active substance and this oxidation or ammoxidation is described in the introduction of the present invention. The catalyst bed may be a fixed bed, a moving bed or a fluid bed. As described in DE-A 10118814 or PCT / EP / 02/04073 or DE-A 10051419, for example by molding or pelletizing in the case of unsupported catalysts or by application to the support (production of coated catalysts) Can be achieved.

  The support used in the case of the coated catalyst for the multimetal oxide material M obtained according to the invention and its successors is preferably chemically inert, for example the multimetal oxide obtained according to the invention Essentially absent from the partially catalyzed gas phase oxidation or ammoxidation of hydrocarbons (eg propane and / or propene to acrylic acid), alcohols or aldehydes catalyzed by material M and its successors.

  In accordance with the present invention, suitable materials for the support are in particular alumina, silica, clay, kaolin, steatite (preferably steatite from C-220 type CeramTec (Germany), preferably having a low water-soluble alkaline component. ), Silicates such as pumice, aluminum silicate and magnesium silicate, silicon carbide, zirconium dioxide and thorium dioxide.

  The surface of the support may be smooth or rough. In general, the surface of the support is rough because the roughness of the surface generally increases the adhesion strength of the applied active substance coating.

Often the surface roughness R _z of the support is in the range of 5-200 μm, often in the range of 20-100 μm (determined according to DIN 4768 sheet 1 using “Hommel Tester for DIN-ISO surface parameters” from Hommelwerke, Germany) .

  Furthermore, the support material may be porous or non-porous. Suitably the support material is non-porous (total volume of ≦ 1% by volume, based on the volume of the support).

  The thickness of the active oxide material coating present in the coated catalyst according to the invention is usually between 10 and 1000 μm. However, it may be 50 to 700 μm, 100 to 600 μm, or 150 to 400 μm. Other possible coating thicknesses are 10-500 μm, 100-500 μm or 150-300 μm.

  In principle, any desired geometric structure of the support is suitable for the method according to the invention. The longest size is in principle 1 to 10 mm. However, spheres or cylinders, in particular hollow cylinders, are preferably used as the support. A convenient diameter of the spherical support is 1.5-4 mm. When a cylinder is used as the support, this length is preferably 2 to 10 mm and its diameter is preferably 4 to 10 mm. In the case of an annular shape, the wall thickness is usually 1 to 4 mm. An annular support suitable according to the invention may also have a length of 3-6 mm, an outer diameter of 4-8 mm and a wall thickness of 1-2 mm. However, the annular support may also be 7 mm x 3 mm x 4 mm or 5 mm x 3 mm x 2 mm (outer diameter x length x inner diameter) dimensions.

  The production of the coated catalyst, according to the invention, pre-forms the multi-metal oxide material M or subsequent substance, converts it into a finely divided shape, and finally converts them to the surface of the support with the aid of a liquid binder. By applying, it can be achieved most easily. For this purpose, the surface of the support is most easily moistened with a liquid binder, and the active substance coating is followed by a finely divided active multimetal oxide material M obtained according to the invention or finely divided. By contacting with a substance, it is adhered to a moist surface. Finally, the coated substrate is dried. Of course, the procedure is repeated periodically to achieve a thicker coating thickness. In this case, the coated basic body becomes a new “support” or the like.

  The fineness of the catalytically active multi-metal oxide material M of general formula (I) or its successor applied to the surface of the support is of course adapted to the desired coating thickness. For coating thicknesses in the range of 100-500 μm, for example, at least 50% of the total number of powder particles pass through a mesh size screen of 1-20 μm and the numerical proportion of particles with the longest size exceeding 50 μm An active substance powder of less than 10% is suitable. In principle, the longest size distribution of the powder particles corresponds to a Gaussian distribution as a result of the product. Often the particle size distribution is as follows:

here:
D = particle diameter;
x = percentage of particles with diameter ≧ D; and y = percentage of particles with diameter <D.

  In order to carry out the coating process described on an industrial scale, it is advisable to use, for example, the operating principle disclosed in DE-A 2909671 and the one described in DE-A 10051419, for example the support to be coated The body is preferably tilted (tilt angles are in principle ≧ 0 ° and ≦ 90 °, generally ≧ 30 ° and ≦ 90 °, the tilt angle is the angle between the central axis of the rotating container and the horizontal plane) For example, first put in a rotating pan or coating drum). Under two metering devices arranged at a distance in succession, the rotating container transports, for example, a spherical or cylindrical support. The first of the two metering devices suitably corresponds to a nozzle (eg a spray nozzle for treating compressed air), whereby the support rotating in the rotating pan is sprayed with a liquid binder and in a controlled manner. Moistened. The second metering device is located outside the spray cone of the liquid binder to be sprayed and serves to supply finely divided oxidizing actives (for example via a shaking trough or powder screw). A spherical support wetted in a controlled manner is dissolved in the supplied active substance powder and compressed by a rotational movement on the outer surface of the support, for example cylindrical or spherical, to obtain a coherent coating.

  If necessary, the support supplied again in this way with the base coating passes through the spray nozzle during the subsequent rotation, is wetted thereby in a controlled manner, and is therefore finely divided during additional movements etc. Additional coatings of oxidatively active substances can be dissolved (in principle no intermediate drying is necessary). The finely divided oxidizing active substance and the liquid binder are in principle supplied continuously and simultaneously.

After the coating is finished, the liquid bonding agent can be removed by the action of a hot gas such as N ₂ or air. Surprisingly, the described coating operation method gives fully satisfactory adhesion of both the continuous coating to each other and the base coating to the surface of the support.

  An important aspect of the coating method described above is that the wetting of the coated support surface is performed in a controlled manner. That is, this means that the support surface is adequately wetted in such a way that it has absorbed liquid binder but the liquid phase itself is not visible on the support surface. If the support surface is too wet, the finely divided catalytically active oxide material is absorbed on the surface or solidifies to form individual lumps. Detailed information on this content is described in DE-A 2909671 and DE-A 10051419.

  The above-mentioned final removal of the used liquid binder can be carried out in a controlled manner, for example by evaporation and / or sublimation. In the simplest case, it can be achieved by the action of hot gas at the corresponding temperature (often 50-300 ° C, often 150 ° C). However, only pre-drying can be achieved by the action of hot gas. Thereafter, final drying can be accomplished, for example, in any type of drying oven (eg, belt dryer) or in a reactor. The applied temperature must not exceed the calcination temperature used for the production of the oxidation active substance. Drying can of course be achieved exclusively in a drying oven.

  Independent of the type and geometry of the support, the following may be used as binders for the coating process: water, monohydric alcohols such as ethanol, methanol, propanol and butanol, ethylene glycol, 1,4-butane. Polyhydric alcohols such as diol, 1,6-hexanediol or glycerol, monovalent or polybasic organic carboxylic acids such as propionic acid, oxalic acid, malonic acid, glutaric acid or maleic acid, ethanolamine or Amino alcohols such as diethanolamine, and mono- or polyfunctional organic amides such as formamide. Convenient binders are also from 10 to 80% by weight of organic compounds which are soluble in 20 to 90% by weight of water and water and have a boiling point or sublimation temperature of> 100 ° C., preferably> 250 ° C. at atmospheric pressure (1 atm). Is a solution. Conveniently, the organic compound is selected from the above list of possible organic binders. Preferably, the organic part of the aqueous binder solution described above is 10-50, particularly preferably 20-30% by weight. Thereby, suitable organic components are also mono- and oligosaccharides such as glucose, fructose, sucrose or lactose and polyethylene oxides and polyacrylates.

  Suitable geometries (both non-supported and coated catalysts) are spheres, non-hollow cylinders and hollow cylinders (annular). The longest size of the above-described geometric structure is in principle 1 to 10 mm. In the case of a cylinder, its length is preferably 2 to 10 mm, and its outer diameter is preferably 4 to 10 mm. In the case of an annular shape, the wall thickness is usually 1 to 4 mm. A suitable annular unsupported catalyst may also have a length of 3-6 mm, an outer diameter of 4-8 mm and a wall thickness of 1-2 mm. However, annular unsupported catalysts with dimensions of 7 mm x 3 mm x 4 mm or 5 mm x 3 mm x 2 mm (outer diameter x length x inner diameter) are also possible. Suitable geometries of the multimetal oxide active substance M obtained in accordance with the invention and its successors are of course also all those in DE-A 10101695.

Special surface area of the multimetal oxide material M obtained according to the invention (and its successor materials) often 1~80m ² / g or ^{40 m} 2 / g, often 11 or 12~40m ² / g, often 15 or 20 it is 40 or ^30m 2 / g (BET method, determined by nitrogen).

  In all other cases, the statements made in DE-A 10303526 are applicable to the multi-metal oxide material M obtained according to the invention and its subsequent substances.

  This means that the multi-metal oxide material M obtained according to the invention and its subsequent substances also have, of course, essentially only diluent effects such as silica, titanium dioxide, alumina, zirconium oxide and niobium oxide, It means that it can be used as catalytically active material in a finely divided, eg colloidal, diluted form.

  The dilution mass ratio may be up to 9 (diluent): 1 (active substance), for example possible dilution mass ratios are for example 6 (diluent): 1 (active substance) and 3 (diluent substance): 1. (Active substance). Diluent mixing can be accomplished before and / or after heat treatment.

  The multi-metal oxide material M and its successors obtained according to the invention are a mixture of saturated and / or unsaturated hydrocarbons and alcohols and aldehydes, either as such or in diluted form as described above (as already described). Suitable as active substances for partially catalyzed partial gas phase oxidation (including oxygen dehydrogenation) and / or ammoxidation (for example during the process according to DE-A 10316465).

  Such saturated and / or unsaturated hydrocarbons are in particular ethane, ethylene, propane, propylene, n-butane, isobutane or isobutene. The end products thus obtained are in particular acrolein, acrylic acid, methacryloline, methacrylic acid, acrylonitrile and methacrylonitrile. However, they are also suitable for partial gas phase oxidation and / or ammoxidation catalyzed by the hybridisation of compounds such as acrolein and metaacrolein.

  However, ethylene, propylene and acetic acid can also be target products.

In this specification, complete oxidation of hydrocarbons, alcohols and / or aldehydes means that all the carbon contained in the hydrocarbons, alcohols and / or aldehydes is converted to carbon oxides (CO, CO ₂ ). It is understood.

  All other reactions of hydrocarbons that add oxygen molecules during the reaction are incorporated herein under the term partial oxidation. Additional addition of ammonia during the reaction is considered partial ammoxidation.

  The multi-metal oxide material M and its successors obtained according to the present specification are preferably propane to acrolein and / or acrylic acid, propane to acrylic acid and / or acrylonitrile, propylene to acrolein and / or acrylic acid. , Propylene to acrylonitrile, isobutane to methacrylolein and / or methacrylic acid, isobutane to methacrylic acid and / or methacrylonitrile, ethane to ethylene, ethane to acetic acid, and ethylene Suitable as catalytically active material for conversion to acetic acid.

  Such partial oxidation and / or ammoxidation (depending on the choice of the ammonia content in the reaction gas mixture controlled in a manner known per se, the reaction is either exclusively as partial oxidation or exclusively as partial ammoxidation or Can be designed essentially as a superposition of two reactions; see eg WO 98/22421), which is known per se from prior art general stoichiometric I multi-metal oxide materials and is quite comparable It can be implemented by the method.

  If the hydrocarbon used is crude propane or crude propene, this preferably has a composition as described in DE-A 10246119 or DE-A 10118814 or PCT / EP / 02/04073. The operating methods are also preferably as described therein.

  The partial oxidation of propane to acrylic acid carried out using a catalyst comprising a multimetal oxide M active substance (or successor active substance) is, for example, EP-A 608838, EP-A 1407819, WO 00/29106, JP-A10. -36311 and EP-A 1192987.

  For example, air, oxygen-rich air, oxygen-depleted air, or pure oxygen can be used as a source of the desired oxygen molecules.

Such a process is advantageous even when the reaction gas starting mixture does not contain a noble gas, in particular helium, as an inert diluent gas. Otherwise, the reaction gas starting mixture can of course contain inert diluent gases such as N ₂ , CO and CO ₂ in addition to propane and oxygen molecules. As a component of the reaction gas mixture, water vapor is advantageous according to the invention.

  This is because the multimetal oxide active substance M obtained according to the invention or its successor is at a reaction temperature of, for example, 200 to 550 ° C. or 230 to 480 ° C. or 300 to 440 ° C. and 1 to 10 bar or 2 to 5 bar. It means that the charged reaction gas starting mixture may have, for example, the following composition:

Propane 1-15, preferably 1-7% by volume,
44-99% by volume of air and 0-55% by volume of water vapor.

  A reaction gas starting mixture containing water vapor is preferred.

  The following are suitable as other possible compositions of the reaction gas starting mixture.

70-95% by volume of propane,
5-30% by volume of oxygen molecules and 0-25% by volume of water vapor.

Naturally, product gas mixtures which are not exclusively composed of acrylic acid are also obtained in this way. Rather, in addition to propane unconverted, the product gas mixture contains propene to be separated from acrylic acid, _{acrolein, CO 2, CO, H 2} O, acetic acid, a secondary component such as propionic acid.

  This can be achieved in a known manner from the gas phase oxidation catalyzed by the hybridisation of propene to acrylic acid.

  This is because the acrylic acid contained is absorbed by water or absorbed by a high boiling inert hydrophobic organic solvent (for example, a mixture of diphenyl ether and difil, which may optionally contain additives such as dimethyl phthalate). Means that it can be removed from the product gas mixture. The resulting mixture of absorbent and acrylic acid can then be worked up by rectification, extraction and / or crystallization in a manner known per se to obtain pure acrylic acid. Alternatively, the initial isolation of acrylic acid from the product gas mixture can also be achieved by fractional condensation, for example as described in DE-A 19924532.

  The resulting aqueous acrylic acid condensate can then be further purified, for example, by fractional crystallization (eg, suspension crystallization and / or hierarchical crystallization).

  The residual gas mixture remaining from the initial isolation of acrylic acid contains in particular unconverted propane and is preferably recycled for gas phase oxidation. For this purpose, it may be partly or completely separated from the residual gas, for example by fractional rectification under pressure, and then reused for gas phase oxidation. However, it is more convenient to contact the residual gas with a hydrophobic organic solvent that can selectively absorb propane in the extraction device (eg, by passing the gas through).

  By subsequent desorption and / or removal of air, the absorbed propane may be released again and can be reused in the process according to the invention. In this way, inexpensive total propane conversion can be accomplished. As with other separation methods, propene formed as a secondary component cannot in principle be separated from propane or cannot be separated completely and circulates with them. This also applies in the case of other homologous saturated and olefinic hydrocarbons. In particular, it is very generally true for the partial oxidation and / or ammoxidation catalyzed by the hybridisation of saturated hydrocarbons according to the invention.

  The multi-metal oxide material M obtained in accordance with the present invention and its successors can also catalyze the partial oxidation and / or ammoxidation of homologous olefinic hydrocarbons to similar target products. Thus, using the multi-metal oxide material M obtained according to the invention and its successors as active substances, acrylic acid is as described in DE-A 10118814 or PCT / EP / 02/04073 or JP-A 7-53448, It can be produced by partial gas phase oxidation catalyzed by the hybrid of propene as oxygen molecules.

  This means that a single reaction zone A is sufficient to carry out the process. In this reaction zone, a catalyst containing the multimetal oxide material A obtained according to the invention exclusively or containing a successor substance is present as a catalytically active substance.

  This is unusual because the gas phase oxidation catalyzed by the hybridization of propene to acrylic acid is very commonly performed in two steps in continuous time. In the first stage, usually propene is essentially oxidized to acrolein, and in the second stage, usually acrolein formed in the first stage is oxidized to acrylic acid.

  Thus, conventional methods of gas phase oxidation catalyzed by hybridization of propene to acrylic acid typically use a special catalyst type tailored to the oxidation stage of each of the two above mentioned oxidation stages.

  This means that the conventional method of gas phase oxidation catalyzed by the hybridisation of propene to acrylic acid is treated in two reaction zones, in contrast to the method according to the invention.

  In the process of partial oxidation of propene, it is of course possible that only one or more catalysts comprising a multi-metal oxide M obtained according to the invention or containing a successor are present in one reaction zone A. is there. Of course, the catalyst used may be diluted with an inert material as recommended, for example, as a support material herein.

  In the method of partial oxidation of propene, only one temperature of the heating medium for heating the reaction zone A or one temperature changing along the reaction zone A can be distributed along one reaction zone A . This temperature change may be an increase or a decrease.

  When the propene partial oxidation process according to the present invention is carried out as fixed bed oxidation, it is suitably achieved in a tube built-in reactor whose catalyst tubes are packed with catalyst. Usually a liquid, in principle a salt bath, is passed as a heating medium around the catalyst tube.

  Next, multiple temperature zones along the reaction zone A can be realized in a simple manner by passing one or more salt baths around the catalyst tube for each section along the catalyst tube.

  In view of the reactor, the reaction gas mixture passes through the catalyst tube in either forward or reverse flow with respect to the salt bath. The salt bath itself can perform a purely parallel flow to the catalyst tubes. Of course, the transverse flow may also be superimposed on it. In general, the salt bath may also provide a serpentine flow around the catalyst tube that is forward or reverse flow to the reaction gas mixture only in view of the reactor.

  In the propene partial oxidation method, the reaction temperature along the entire reaction area A may be 200-500 ° C. Usually 250 to 450 ° C. The reaction temperature is preferably 330 to 420 ° C, particularly preferably 350 to 400 ° C.

  In the propene partial oxidation process, the treatment pressure may be 1 bar, less than 1 bar, or more than 1 bar. In accordance with the present invention, typical process pressures are 1.5 to 10 bar, often 1.5 to 5 bar.

  The propene used in the propene partial oxidation process need not meet any special high requirements regarding its purity.

As already mentioned, the full one-stage or two-stage method of gas phase oxidation catalyzed by the hybridization of propene to acrolein and / or acrylic acid is very common, for example, propene having the following two specifications ( Can also be used perfectly as a propene in this way without problems:
a) Polymer grade propylene ≧ 99.6 wt% propene ≦ 0.4 wt% propane ≦ 300 wt ppm ethane and / or methane ≦ 5 wt ppm C ₄ -hydrocarbon ≦ 1 wt ppm acetylene ≦ 7 wt ppm ethylene ≦ 5 Weight ppm water ≦ 2 weight ppm O ₂
≦ 2 ppm by weight Sulfur-containing compounds (in terms of sulfur)
≦ 1 ppm by weight Chlorine-containing compound (chlorine conversion)
≦ 5 wt ppm CO ₂
≦ 5 ppm by weight CO
≦ 10 wt ppm cyclopropane ≦ 5 wt ppm propadiene and / or propyne ≦ 10 wt ppm C ₂₅ -hydrocarbon and ≦ 10 wt ppm carbonyl-containing compound (Ni (CO) ₄ conversion)
b) Chemical grade propylene ≧ 94 wt% propene ≦ 6 wt% propane ≦ 0.2 wt% methane and / or ethane ≦ 5 wt ppm ethylene ≦ 1 wt ppm acetylene ≦ 20 wt ppm propadiene and / or propyne ≦ 100 wt ppm cyclo Propane ≦ 50 ppm by weight Butene ≦ 50 ppm by weight Butadiene ≦ 200 ppm by weight C ₄ -hydrocarbon ≦ 10 ppm by weight C ₂₅ -hydrocarbon ≦ 2 ppm by weight Sulfur-containing compound (in terms of sulfur)
≦ 0.1 ppm by weight Sulfide-containing compound (H ₂ S conversion)
≦ 1 ppm by weight Chlorine-containing compound (chlorine conversion)
≦ 0.1 wt ppm Chloride-containing compound (Clθ conversion) and ≦ 30 wt ppm water However, a process for hybrid catalyzed gas phase oxidation of one or two stages of propene to acrolein and / or acrylic acid Or, the usefulness of crude propene to known methods does not very generally adversely affect all the above-mentioned possible impurities of propene, of course, in the individual amounts described in the crude propene. It can also be included 2 to 10 times each.

  In particular, in the case of saturated hydrocarbons, water vapor, carbon oxides and oxygen molecules, in any case these are compounds that are added to the reaction as either an inert diluent gas or a large amount of reactants in the above-described method, This applies. Typically, the crude propene itself is regenerated gas, air and / or oxygen molecules and / or diluted air and / or non-reacted due to the process of gas phase oxidation catalyzed by the hybridization of propene to acrolein and / or acrylic acid. Used as a mixture with active gas.

  However, another suitable propene feedstock for the process according to the invention is formed as a by-product in a process different from the process according to the invention, for example propene containing up to 40% by weight of propane. Furthermore, the propene may be accompanied by other impurities that do not essentially interfere with the process according to the invention.

  Both pure oxygen and air or oxygen rich air or oxygen depleted air may be used as oxygen feedstock for the propene partial oxidation process.

In addition to molecular oxygen and propene, the reaction gas starting mixture used in the propene partial oxidation process also typically contains at least one diluent gas. Nitrogen, carbon oxides, noble gases and lower hydrocarbons such as methane, ethane or propane are suitable per se (higher hydrocarbons such as C ₄ -hydrocarbons should be avoided). Often, water vapor is also used as the diluent gas. The gas mixture described above often forms a diluent gas for the partial propene oxidation process.

  The partial oxidation catalyzed by the hybrid of propene is advantageously achieved in the presence of propane.

Typically, the reaction gas starting mixture for the propene oxidation process has the following composition (molar ratio):
Propene: _{oxygen: H} 2 O: other diluent gases = 1: (0.1-1) :( 0-70) :( 0:20)
Preferably, the above ratio is 1: (1-5) :( 1-40) :( 0-10).

  When propane is used as the diluent gas, it can be more conveniently partially oxidized to acrylic acid as described.

According to the invention, the reaction gas starting mixture advantageously contains molecular nitrogen, CO, CO ₂ , water vapor and propane as diluent gas.

  The propane: propene molar ratio in the propene oxidation process may be assumed to be the following values: 0-15, often 0-10, often 0-5, suitably 0.01-3.

  The packing of the catalyst bed with propene during the partial propene oxidation process may be, for example, 40-250 l (STP) / l / h or more. The charge with the reaction gas starting mixture is often in the range of 500 to 15000 l (STP) / l / h, often in the range of 600 to 10000 l (STP) / l / h, often 700 to 5000 l (STP) / l / h.

Of course, during the process of partial oxidation of propene to acrylic acid, a product gas mixture is obtained which is not exclusively composed of acrylic acid. Rather, the product gas mixture, in addition to unconverted propene, propane, _{acrolein, CO 2, CO, H 2} O, acetic acid, a secondary compound that must be separated from acrylic acid such as propionic acid Contains.

  This can be achieved in a generally known manner from a two-stage gas phase oxidation (performed in two reaction zones) catalyzed by the hybridisation of propane to acrylic acid.

  This is because the acrylic acid contained is absorbed by water or by a high boiling inert hydrophobic organic solvent (for example, a mixture of diphenyl which may optionally contain additives such as diphenyl ether and dimethyl phthalate). Means that the product gas mixture can be removed. The resulting mixture of absorbent and acrylic acid can then be worked up in a manner known per se by rectification, extraction and / or crystallization to obtain pure acrylic acid. Alternatively, the initial separation of acrylic acid from the product gas mixture can also be achieved by fractional condensation, for example as described in DE-A 19924532.

  The resulting aqueous acrylic acid condensate can then be further purified, for example, by fractional crystallization (eg, suspension crystallization and / or hierarchical crystallization).

  The residual gas mixture remaining during the initial isolation of acrylic acid contains in particular unconverted propene (and possibly propane). This can be separated from the residual gas mixture, for example by fractional rectification under pressure, and reused for gas phase oxidation according to the invention. However, it is more convenient to contact the residual gas in the extraction apparatus with a hydrophobic organic solvent that can selectively absorb propene (and optionally propane) (eg, by passing the gas).

  Subsequent desorption and / or removal of air allows the absorbed propene (and optionally propane) to be released again and reused in the process according to the invention. In this way, an inexpensive total propene conversion can be accomplished. When propene is subjected to partial oxidation in the presence of propane, propene and propane are preferably separated and reused.

  In a completely corresponding manner, the multimetal oxide M and its successors obtained according to the invention can be used as catalysts for the partial oxidation of isobutane and / or isobutene to methacrylic acid.

Use for the ammoxidation of propane and / or propene can be achieved, for example, as described in EP-A 529853, DE-A 2351151, JP-A 6-166668 and JP-A 7-232011.
Use for the ammoxidation of n-butane and / or n-butene can be achieved, for example, as described in JP-A6-211767.

  Use of ethane or ethylene for oxygen dehydrogenation or additional reaction to acetic acid can be achieved as described in US-A 4,250,346 or EP-B 261264.

  The use for the partial oxidation of acrolein to acrylic acid can be achieved as described in DE-A 10261186.

  The multi-metal oxide material M and its successors obtained according to the present invention can, however, also be merged with other multi-metal oxide materials (for example mixing, compressing and firing the finely divided substances as appropriate) Or mixed, dried and fired as a slurry (preferably aqueous) (eg as described in EP-A 529853)). Calcination is preferably accomplished once more under inert gas.

  The resulting multi-metal oxide mixture (see below for the total material) is preferably ≧ 50% by weight, particularly preferably ≧ 75% by weight of the multi-metal oxide material M or its successor material obtained according to the invention. Particularly preferably ≧ 90 wt% or ≧ 95 wt%, which is more suitable for the partial oxidation and / or partial ammoxidation discussed herein.

  In the case of total materials, the geometric shaping is suitably achieved as described for the multi-metal oxide material M obtained according to the invention and its successors.

  Due to the hybrid gas-catalyzed partial gas phase oxidation of propane to acrylic acid, the multimetal oxide material M obtained in accordance with the present invention, its successor material and the multimetal oxide material or catalyst comprising such a material are: Preferably, it is put into the process as described in DE-A 10122027.

Finally, the excellent reproducibility using the method according to the invention is due to the fact that the desired multi-metal oxide M is obtained in an environment essentially containing only water and its constituents H, O and OH. Should be stated. In this way, the multimetal oxide M is obtained under the so-called natural pH, which clearly makes the operating procedure particularly robust.
Examples and Comparative Example A) Manufacture of multi-metal oxide material Example 1 Manufacture of multi-metal oxide material with stoichiometric Mo ₁ V _0.32 Te _0.027 O _x Introduced in finely divided form into an agitator and an autoclave with an internal volume of 2.5 l:
123.27 g of MoO ₃ (Riedel-de-Haen brand, 30926 Seelze; containing MoO ₃ >99.9%; Mo 0.86 mol);
23.06 g VO ₂ (from Alfa Aesar, 76057 Karlsruhe; VO ₂ content = 99.5%; VO ₂ 0.28 mol, V oxidation state = 4.03);
3.69 g of TeO ₂ (from Sigma Aldrich, 82018 Taufkirchen; TeO ₂ >99%; TeO ₂ 0.023 mol);
And 1500 ml of water.

The autoclave lid is closed and the air portion present at the top of the aqueous phase in the autoclave is exchanged for nitrogen by flushing with nitrogen. Thereafter, the autoclave was continuously heated (linearly) to 175 ° C. while continuously stirring (700 rpm) for 10 hours under a self-pressure, and this temperature was maintained while further stirring for 48 hours. Next, it was cooled to room temperature (25 ° C.). The autoclave was opened and the black powder formed was collected by filtration, washed 3 times with 200 ml of water at a temperature of 25 ° C., and then dried at 80 ° C. for 12 hours in a drying oven under reduced pressure.
Experiments performed in the manner described were repeated 10 times. In all cases, the same results were obtained as follows.

  The i-phase is obtained exclusively as shown by the powder X-ray diffraction diagram (XRD) shown in FIG. Related scanning electron micrographs (SEM) (FIG. 2, three different magnifications) show needle-like crystals having a high length-thickness ratio of about 50-100.

  The advantage of “needle” or “fibrous” is that the fact that the surface of other (additional) crystals is more accessible to the catalyst than isotropic materials is likely to be found.

Titration analysis shows that V in the formed i-phase has an oxidation state of 4.02 to 4.05. The specific surface area was 45 m ² / g. Chemical analysis gave satisfactory agreement on the stoichiometry to be metered.

Comparative Example 1 Production of multi-metal oxide material of stoichiometric Mo ₁ V _0.32 Te _0.027 O _x to be metered in The following from Example 1 in an autoclave in a finely divided shape Introduced in:
151,87 g of (NH ₄ ) ₆ Mo ₇ O ₂₄ 4H ₂ O (from HC Starck, 38642 Goslar; MoO ₃ containing 81.5%; Mo 0.86 mol);
Vanadyl sulfate hydrate VOSO ₄ (H ₂ O) _x 66.64 g (from Alfa Aesar, 76057 Karlsruhe; V content = 21.4 wt%; V 0.28 mol)
TeO ₂ 3.69 g (as in Example 1)
And 1500 ml of water.

  Next, the operation method was carried out as in Example 1 (hydrothermally). The experiment carried out in the manner described was repeated 10 times. For the two cases, an increased i-phase portion occurred in the formed multi-metal oxide powder. On the other hand, in the other 8 experiments, a phase mixture containing only a small portion of i-phase was obtained.

The following were identified among other phases: JPDS index 81-2414 (c) phase [(V _0.12 Mo _0.88 ) O _2.94 , hexagonal], JPDS index 05-0508 phase [ MoO ₃ , orthorhombic], JPDS index 47-0872 phase [NMo _5.35 O _15.75 (OH) _1.6 · 1.7 H ₂ O] and JPDS index 77-0649 (c) phase [(V _{0 .95} Mo _0.97 ) O ₅ , triclinic crystal].

Example 2 Production of a multi-metal oxide material of stoichiometric Mo ₁ V _0.32 Bi _0.027 O _x to be metered in The following from Example 1 in an autoclave in a finely divided shape: Introduced:
123.27 g of MoO ₃ (as in Example 1)
VO ₂ 23.06 g (as in Example 1)
Bi ₂ O ₃ 5.36 g (Riedel-de Haen brand, 30926 Seelze; Bi ₂ O ₃ ≧ 99.5%; Bi 0.023 mol)
And 1500 ml of water.

  Next, the operation method was carried out as in Example 1 (hydrothermally).

  Experiments performed in the manner described were repeated 10 times. In all cases, the same results were obtained as follows.

  A powder X-ray diffraction diagram (see FIG. 3) containing the i-phase exclusively in all cases was obtained for the black powder. The associated scanning electron micrographs (FIG. 4, three different magnifications) show needle-like crystals having a high length / thickness ratio of about 30-150.

Chemical analysis gave satisfactory agreement on the stoichiometry to be metered. According to titration analysis, V in the formed i-phase had an oxidation state of 4.02 to 4.07. The specific surface area was 38 m ² / g.

Comparative Example 2 Production of Multi-Metal Oxide Material with Stoichiometric Mo ₁ V _0.32 Bi _0.027 O _x The operating method was as in Example 2. However, 151.87 g of (NH ₄ ) ₆ Mo ₇ O ₂₄ · 4H ₂ O (as in Comparative Example 1) was used instead of MoO ₃ and vanadyl sulfate hydrate VOSO ₄ (H ₂ O) _x 66. 64 g (as Comparative example 1) was used instead of VO _2. The experiment was repeated 10 times. For the two cases, an increased proportion of i-phase was obtained in the black powder produced.

On the other hand, in the other 8 reproductions, a phase mixture containing only a small portion of i-phase was obtained. The remaining phases are as JPDS index 05-0508 phase [MoO ₃ , orthorhombic], and as JPDS index 47-0772 phase [HMo _5.35 O _15.75 (OH) _1.6 · 1.7 H ₂ O]. JPDS index 48-0744 phase (BiVO ₄ , tetragonal), JPDS index 85-0630 phase (Bi _0.88 Mo _0.37 V _0.63 O ₄ ), JPDS index 70-2321 (c) phase [ As the crystalline structure of Sb ₄ Mo ₁₀ O ₃₁ , orthorhombic], the crystalline structure of JPDS index 33-0104 phase (Sb ₄ Mo ₁₀ O ₃₁ , hexagonal crystal) and / or JPDS index 77-0649 (c) phase [(V _0.95 Mo _0.97 O ₅ , triclinic). In addition, it was present when there was an additional phase, but could not be additionally identified based on XRD reflection.

Example 3 Production of a multi-metal oxide material of stoichiometric Mo ₁ V _0.32 Bi _0.027 O _x to be metered in. The operating procedure was as in Example 2. However, the vanadium raw materials were 2.85 g V powder (from Chempur, 762304 Karlsruhe; V containing>99.5%; V 0.056 mol) and 20.36 g V ₂ O ₅ (Gesellschaff fur Elektrometallurgie (GfE), 90431 Nurnberg ₂ ; A mixture containing O ₅ = 99.97%; V 0.224 mol) was used.

  The autoclave was closed and replaced with nitrogen by flushing with nitrogen the portion of air present above the aqueous solution in the autoclave.

  Thereafter, the autoclave was continuously heated (linearly) to 90 ° C. while continuously stirring (700 rpm) over 3 hours under self-pressure, and stirred at this temperature for 10 hours.

  Thereafter, the mixture was continuously heated (linearly) to 175 ° C. with continuous stirring (700 rpm) under self-pressure for 8 hours, and this temperature was maintained while stirring for 24 hours. Thereafter, the mixture was cooled to room temperature (25 ° C.), and the formed black powder was collected by filtration, washed with water and dried as in Example 1.

  The experiment carried out in the manner described was repeated 10 times. The result similar to Example 2 was obtained in 6 times out of 10 operation methods.

  In 4 of the 10 operating procedures, a solid corresponding to that from Comparative Example 2 crystallized.

Example 4 Production of multi-metal oxide material with stoichiometric Mo ₁ V _0.25 O _x to be metered in The operating procedure was as in Example 1. _However, using only VO 2 18.0 g instead of _VO 2 23.06 g, were excluded Te compound.

Example 5 Preparation of a stoichiometric Mo ₁ V _0.25 Nb _0.098 Bi _0.042 O _x multimetal oxide material The procedure is as in Example 1, ie once again MoO ₃ 123. In accordance with 27 g and the desired stoichiometry, the required amounts of VO ₂ , Nb ₂ O ₅ and Bi ₂ O ₃ at this point were metered in.

Example 6 Preparation of a stoichiometric Mo ₁ V _0.3 Sb _0.25 Nb _0.12 O _x multimetal oxide material The operating procedure is as in Example 1, ie once again MoO ₃ 123. In accordance with 27 g and the desired stoichiometry, the required amounts of VO ₂ , Sb ₂ O ₃ and Nb ₂ O ₅ at this point were metered in.

Example 7 _Production of a stoichiometric Mo ₁ V _0.3 Nb _0.13 Sb _0.13 O _4.125 multimetal oxide material The procedure is as in Example 1, ie once again MoO ₃ According to 123.27 g and the desired stoichiometry, the required amounts of VO ₂ , Nb ₂ O ₅ and Sb ₂ O ₃ at this point were metered in.

Example 8 Production of multi-metal oxide material of stoichiometric Mo ₁ V _0.3 Nb _0.13 Ni _0.13 O _x to be metered in The procedure is as in Example 1, ie once again MoO ₃ 123. In accordance with 27 g and the desired stoichiometry, the required amounts of VO ₂ , Nb ₂ O ₅ and NiO at this point were metered in.

Example 9 Preparation of a stoichiometric Mo ₁ V _0.3 Nb _0.13 Co _0.13 O _x multimetal oxide material The operating procedure is as in Example 1, ie once again MoO ₃ 123. In accordance with 27 g and the desired stoichiometry, the required amounts of VO ₂ , Nb ₂ O ₅ and CoO at this point were metered in.

Example 10 Production of a multi-metal oxide material of stoichiometric Mo ₁ V _0.3 Nb _0.13 Cr _0.031 O _x to be metered in The operating procedure is as in Example 1, ie once again MoO ₃ 123. In accordance with 27 g and the desired stoichiometry, the required amounts of VO ₂ , Nb ₂ O ₅ and Cr ₂ O ₃ at this point were metered in.

Example 11 Production of multi-metal oxide material of stoichiometric Mo ₁ V _0.32 Bi _0.027 O _x to be metered in The operating procedure was as in Example 2. 100 g of the resulting dried multi-metal oxide material was added to 500 g of 10% aqueous nitric acid concentration. The resulting aqueous suspension was stirred under reflux at 80 ° C. for 5 hours. Next, it was cooled to 25 ° C. The solid present in the black suspension was separated from the aqueous phase by filtration, washed to the nitrate free with water and then dried overnight at 120 ° C. in an air-permeable drying oven.

Example 12
The operating method was as in Example 2. 100 g of the resulting dried multimetal oxide material are placed in a rotating spherical furnace (internal volume 1 liter) according to FIG. 1 of DE-A1003338 under a stream of molecular nitrogen (10 l (STP) / l ) Heated from room temperature to 500 ° C. at a heating rate of 2 ° C./min and maintained this temperature for 6 hours while maintaining a nitrogen stream. Next, cooling to 25 ° C. was achieved by leaving it to stand while maintaining a nitrogen stream.

Example 13
As in Example 5, except that the thermal post-treatment is accomplished as in Example 12.

Example 14
As in Example 6, except that the thermal post-treatment is accomplished as in Example 12.

Example 15
As in Example 7, except that thermal post-treatment is achieved as in Example 12.

Example 16
As in Example 10, except that the thermal post-treatment is accomplished as in Example 12.
B) Production of coated catalyst from multimetal oxide material produced in A) Each active substance powder was ground in a Retsch grinder (Retsch, centrifugal grinder from Germany, type ZM100) ( Particle size ≦ 0.12 mm).

  In each case, 38 g of powder present after grinding, 150 g of spherical support having a diameter of 2.2 to 3.2 mm (Rz = 45 μm, support material = Ceramtec, steatite C220 from Germany, total pores of the support The volume was applied to ≦ 1% by volume based on the total support volume. For this purpose, the support was initially placed in a drum having an internal volume of 2 l (tilt angle of the central axis of the drum relative to the horizontal plane = 30 °). The drum was rotated at 25 revolutions per minute. About 25 ml of a mixture of glycerol and water (glycerol: water weight ratio = 1: 3) was sprayed onto the support through a sprayer nozzle treated with 300 l of compressed air (STP) / h. At the top of the inclined drum in the upper half of the rotating track, the nozzle was mounted in such a way that the spray cone wets the support transported in the drum by a metal driver plate. Finely divided active substance powder was introduced into the drum via a powder screw and the position of powder addition was in the rotating track or under the spray cone. By periodically repeating wetting and powder metering, the support supplied with the base coating itself became the support during the next.

  After coating was complete, the coated support was dried in air in a muffle furnace at 150 ° C. for 16 hours.

Coated catalysts SB1-SB16 and SVB1 and SVB2 were obtained, each containing 20% by weight of active substance. (B1 means that a multimetal oxide according to Example 1 from A) was used; SVB1 was therefore used as a multimetal oxide according to Comparative Example 1 from A) Means)
C) Tubular reactors (inner diameter: 8.5 mm, length: 140 cm, wall thickness: 2.5 cm) produced from the coated catalyst test steel produced in B) in each case B) Each with 35.0 g of each coated catalyst (in all cases the catalyst bed length was about 53 cm). Over the remaining length of the tubular reactor, a spare 30 cm bed of steatite beads (diameter: 2.2-3.2 mm, manufacturer: Ceramtec, Staatite C220) is placed in front of the catalyst bed and continues The same steasite bead bed was placed after the catalyst bed.

  The external temperature T of the filled reaction tube was set to a desired value externally over the entire length by an electrically heated heating mat.

The reaction tube is then fed with a reaction gas starting material having a molar composition of propane: air: H ₂ O = 1: 15: 14 (the inlet side is the next bed side). The residence time (based on the catalyst bed capacity) was 2.4 seconds. The introduction pressure was 2 bar absolute.

  The reaction tube bed was first run in each case at the external temperature T = 350 ° C. of the filled reaction tube for 24 hours before the external temperature was brought to its respective value.

The table below shows the propane conversion obtained (U ^PAN (mol%)), the selectivity of the resulting acrylic acid structure (S) as a function of the coated catalyst used and the set external temperature T (° C.). ₂ shows the structural selectivity (S _PEN (mol%)) of _ACS (mol%)) and propene byproduct.

  US Provisional Patent Application No. 60 / 577,929, filed June 9, 2004, incorporates this application by reference to the writing. Numerous modifications and departures from the present invention are possible in light of the foregoing description. Thus, within the scope of the appended claims, it may be envisaged that the invention may be practiced otherwise than as specifically described herein.

FIG. 1 is a powder X-ray diffraction diagram (XRD) showing that an i-phase is obtained exclusively. FIG. 2 is a related scanning electron micrograph (SEM) showing a needle-like crystal having a high length / thickness ratio of about 50-100. FIG. 3 is a powder X-ray diffraction diagram showing that the i-phase is exclusively contained in all cases with respect to the black powder. FIG. 4 is a related scanning electron micrograph showing an acicular crystal having a high length-thickness ratio of about 30-150.

Claims (18)

General stoichiometry I:
^{_{Mo 1 V a M 1 b M}} 2 c M 3 d M 4 e O n (I)
[Where:
M ¹ = at least one element selected from the group consisting of Al, Ga, In, Ge, Sn, Pb, As, Bi, Se, Te and Sb;
M ² = at least one element selected from the group consisting of Sc, Y, La, Ti, Zr, Hf, Nb, Ta, Cr, W, Mn, Fe, Co, Ni, Zn, Cd and lanthanoids;
M ³ = At least one element selected from the group consisting of Re, Ru, Rh, Pd, Os, Ir, Pt, Cu, Ag, Au;
M ⁴ = at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, and Tl;
a = 0.01-1;
b = ≧ 0-1;
c = ≧ 0-1;
d = ≧ 0 to 0.5;
e = ≧ 0 to 0.5 and n = the number determined by the valence and the frequency of appearance of elements other than oxygen in (I)] In the manufacturing method of subjecting a mixture G of raw materials of elemental constituents of material M to hydrothermal treatment, thereby separating a newly formed solid,
As a raw material of the element constituent component of the multimetal oxide material M, a compound composed of only the element constituent component of the multimetal oxide material M and the element constituent component of water, and those of the element constituent component itself of the multimetal oxide material M Using a raw material selected from the group consisting of elemental forms, and at least a portion of the raw material contains an elemental component contained in these raw materials having an oxidation number lower than the maximum oxidation number of the corresponding elemental component Feature method.   The process according to claim 1, wherein the process is carried out at a temperature of from 120 to 300C.   The process according to claim 1 or 2, wherein the process is carried out at a pressure of> 1 bar to 500 bar.   The method in any one of Claims 1-3 in which at least one part of the raw material of the elemental component V contains the vanadium whose oxidation number is +4 or +3 or +2 or 0. At least one compound selected from the group consisting of VO ₂ , V ₂ O ₃ , VO, V ₆ O ₁₃ , V ₃ O ₇ , V ₄ O ₉ and elemental vanadium is simultaneously used as a raw material for the elemental component V. The method in any one of Claims 1-4. At least 40 mole% of V contained in the mixture G is included as V is the oxidation number <+5 A method according to any one of claims 1-5. At least 70 mole% of V contained in the mixture G is included as V is the oxidation number <+5 A method according to any one of claims 1-5. The stoichiometric coefficients a, b, c and d are simultaneously in the following range:
a = 0.05-0.5
b = 0.01-0.5
c = 0.01-0.5
d = 0.005-0.5 and e = ≧ 0-0.5
The method according to any one of claims 1 to 7 , wherein The stoichiometric coefficients a, b, c and d are simultaneously in the following range:
a = 0.1-0.5
b = 0.1-0.5
c = 0.1-0.5
d = 0.001 to 0.1 and e = ≧ 0 to 0.1
The method according to any one of claims 1 to 7 , wherein At least one element M ¹ is Sb, Bi, selected from the group consisting of Se and Te, A method according to any one of claims 1-9. At least one element of at least 50 mol% of Nb and Ti, Zr, Cr, Ta, W, Fe, Co, is selected from the group consisting of Ni and Zn in a total amount of M ^2, any claim 1-10 The method of crab. At least one element M ³ is Re, it is selected from the group consisting of Pd and Pt, the method according to any one of claims 1 to 11. The method according to any one of claims 1 to 12 , wherein the stoichiometric coefficient e is 0. The method of manufacturing a multi-metal oxide material M of the general stoichiometry I according to claim 1, first out the method according to any one of claims 1 to 13, to separate the solid that is newly formed, heat A method characterized by subjecting to a post-treatment, and then appropriately washing with an organic acid or an aqueous solution thereof, an inorganic acid or an aqueous solution thereof, an alcohol, or hydrogen peroxide or an aqueous solution thereof. The method of manufacturing a multi-metal oxide material M of the general stoichiometry I according to claim 1, first out the method according to any one of claims 1 to 13, to separate the solid that is newly formed, following And washing with an organic acid or an aqueous solution thereof, an inorganic acid or an aqueous solution thereof, alcohol, hydrogen peroxide or an aqueous solution thereof. The method according to any one of claims 1 to 13 , which is carried out under an inert gas atmosphere. The method according to any one of claims 1 to 15 , wherein the thermal aftertreatment and cleaning are carried out under an inert gas atmosphere. The method according to any one of claims 1 to 13 , wherein the weight ratio of the latter during the hydrothermal treatment is 5 to 50% by weight based on the total amount of water and elemental constituent raw materials of the multimetal oxide material M.

Images