MXPA98007078A - Nob metal catalyst composition - Google Patents

Abstract

The present invention relates to a catalyst composition without noble metals that is obtained by: a) the preparation of an aqueous mixture containing: i) a salt of at least one base metal that is selected from the elements having atomic numbers 21-32, 39-42, 48-51, 57-75 and 81-83, ii) phosphate ions, and iii) at least one source of nitrogen, and b) evaporation of the aqueous solution obtained and drying of the composition of catalyst so formed. The prepared catalyst composition can be used to produce hydrogen peroxide and for olefin epoxidation

Description

COMPOSITION OF CATALYST WITHOUT NOBLE METALS The present invention relates to a solid catalyst composition, without noble metals, its preparation, its use to produce hydrogen peroxide and its use in the epoxidation of olefins. Nowadays hydrogen peroxide is widely used as a cleaning oxidant, for example, for bleaching paper and cellulose, to remove S02 from waste gases, in the electronics industry in the manufacture of semiconductors and for sterilization, deodorization or disinfection of packaging materials. In organic chemistry, hydrogen peroxide is used particularly in epoxidation and hydroxylation reactions where hydrogen peroxide can also be generated in situ. According to the prior art, hydrogen peroxide is currently widely prepared by the anthraquinone process (see, Ullmann's Encyclopedia of Industrial Chemistry, 5th edition, vol.A13, pp. 443 ff). The hydrogenation sub-step is usually carried out in the presence of a metallic catalyst such as palladium black or Raney nickel. In addition, heterogeneously catalyzed preparation processes have been described in which the noble metals in different supports are used as catalysts. Thus, in US 5,320,821, Pd / heteropolyacid is used as a catalyst to prepare hydrogen peroxide from the elements. In addition, JP5017106-A describes the use of silica or zeolites together with platinum metals and EP 0 537 836 describes the use of zirconium oxides together with Pd. However, these processes often require the use of halogen compounds as promoters and stabilizers, as described, for example in US 5,320,821. In organic oxidation reactions it is possible to use hydrogen peroxide catalytically formed in situ directly or in combination with peroxo-oxygen transfer agents (see, G. Goor in G. Strukul, "Catalytic Oxidations with Hydrogen Peroxide as Oxidant", pp. 13 -43, 1992 Kluwer Academic Publishers). In particular, the heterogeneous oxidation catalysts are titanium containing zeolites whose preparation is described, for example, in DE 3047798. Zeolites of this type are used to transfer oxygen to the monoolefins and diolefins (see, EP 100 119 and EP 0 190,609). Compared with industrial oxidation by the chlorohydrin process (see K. eissermel, H.-J. Arpe, "Industrielle Organische Chemie", 3rd edition, VCH Verlag (1988) pp. 284-289), the process in accordance with EP 0 100 119 has the advantage of producing, for example, propylene oxide obtainable in high selectivity from propene. In J. Chem. Soc. Commun. (1992) 1446-7), Tatsu i describes the hydrophilization of benzene and the oxidation of hexane using hydrogen / oxygen on palladium metal in silicalite TS-1, but low reaction rates are observed in comparison with hydrogen peroxide. In addition, DE-A 44 25 672 discloses improved noble metal catalysts containing titanium zeolites and processes for preparing propylene oxide from hydrogen, oxygen and propene. The catalyst systems described herein are very satisfactory, for example, in terms of reactivity, selectivity and stability. However, these have the disadvantage, like other heterogeneous catalysts for oxidation known from the prior art, of containing an expensive noble metal as a catalytically active constituent. This is a significant economic disadvantage, particularly for the large-scale industrial production of oxidation products such as propylene oxide. An object of the present invention is to provide a heterogeneous catalyst without noble metals that is also essentially free of halogen atoms and can be used in the preparation of hydrogen peroxide and also in the catalytic oxidation of organic molecules, such as, in particular,, the epoxidation of olefins. We have found that this objective is achieved by a solid catalyst composition containing a base metal component, phosphate and a nitrogen component as essential constituents. The suitable metals according to the present invention are the elements d and f, that is, the elements from the 4th to the 6th period of groups IIIB, IVB, VB, VIB, VTIB, IB, IIB, IIIA, IVA, and VA of the table Periodic, that is, Se, Ti, V, Cr, Mn, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, Cd, In, Sn, Sb, The, Ce, Pr, Nd, Sm, Eu , Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, TI, Pb, Bi, plus Fe, Co, and Ni. The present invention therefore provides a catalyst composition (hereinafter referred to as metal phosphate) which is obtained by: a) preparing an aqueous mixture containing: i) a salt of at least one base metal selected from among the elements that have atomic numbers 21-32, 39-42, 48-51, 57-75 and 81-83; ii) at least one phosphate ion; and iii) at least one nitrogen source; and b) evaporating the obtained aqueous solution and drying the catalyst composition thus formed, with or without slight heating, to maintain its catalytic activity. The aqueous mixture of step a) is preferably obtained by dissolving the components i), ii) and iii) in an aqueous solvent such as water or an aqueous alcoholic, for example, an aqueous ethanolic solvent. However, the preferred solvent is water. The components can be dissolved together or separately from each other. However, preference is given to the separate preparation of the two solutions, one of which contains the salt of the base metal and the other contains the phosphate component, and the subsequent combination of the two solutions. The necessary nitrogen source may be present in one or both solutions. In the preparation of the metal phosphate catalysts of the present invention it is advantageous first to dissolve the metal component in the form of the readily soluble salts in aqueous solution and then to add the phosphate in the dissolved form with constant stirring. The most suitable method of pH selection and temperature range for the preparation of a specific catalyst composition is known to those skilled in the art. In the preparation of the solutions of the component or the aqueous mixture it is usually sufficient to work from 10 to 60 ° C, preferably from approximately 20 to 30 ° C. However, depending on the behavior of the solution of the components that are used, it is possible to use heating of a component solution or of the aqueous mixture above the mentioned value. During the preparation of the component solutions or the mixture, particular measures to adjust the pH usually are not necessary. However, depending on the behavior of the solution of the individual components, the addition of pH adjusting substances, such as customary acids or bases, or customary buffer substances, can be advantageous. The aqueous mixture produced as described in step a) preferably contains the basic metal ions (M) such as metal cations, phosphate (P) and nitrogen source (N) in a molar ratio in the range of about 1: 0.8-1.4: 0-8-4.0, for example, 1: 1: 1 or 1: 1: 4. The respective concentration of the individual components present in the aqueous mixture of the present invention can vary within a wide range and is determined essentially by the solubility of the compounds that are used. However, it is advantageous to prepare aqueous solutions which are as concentrated as possible to save time and the energy requirements for the evaporation of the aqueous mixture as low as possible, as long as the formation of the catalytically active metal phosphate of the present invention is not damaged by this. In this way, for example, the metal component and the phosphate component can be present, independent of each other, in a concentration in the range of about 0.1 to about 1.5 mol / 1, for example, from about 0.25 to about 0.85 mol / 1. . The nitrogen source (s) may be present, for example, in a concentration in the range of about 0.1 to about 5 mol / 1, for example, from about 0.25 to about 3.5 M. When ammonium ions are used as a source of nitrogen, the metal, phosphate and ammonium component will preferably be present in the mixture in approximately equimolar amounts, it being possible for the concentration of each of the three components to be from about 0.25 to about 0.85 mol / l, during the evaporation and drying of the aqueous mixture, the conditions of preference are selected so that the complete loss of the nitrogen component of the catalyst composition is essentially avoided. In particular, the conditions must be selected such that the ratio of nitrogen in the catalyst composition after the end of drying is reduced to no more than about 20-90 mol%, preferably about 50-80 mol%, based on the nitrogen that is used. The method of selecting the most suitable drying conditions for the particular catalyst material is known to those skilled in the art. As shown in the appended examples, it is possible, for example, that the drying of the catalyst composition at a temperature that is too high resulting in complete loss of nitrogen. This loss can be detected by means of a change in the characteristics in the X-ray diffraction patterns of the solid composition, as shown by the comparison of the attached X-ray diffractograms (Figure 1 and Figure 3). In particular, the structure in the diffractogram that is evident for the catalytically active phosphates of the present invention is no longer detected. However, the most important effect of nitrogen loss is a decrease or complete loss of catalytic activity. The catalytically active metal phosphate of the present invention is obtained, for example, when the aqueous mixture is first evaporated to dryness in a pressure range from about 10 to 1000 mbar, for example, about 15-50 mbar, from about 10 to about 200 ° C, for example, approximately 100-140 ° C, and the residue obtained in this way is dried in air at atmospheric pressure from about 30 to about 200 ° C, preferably from about 50 to about 150 ° C, in particular from about 60 to about 140 ° C, for example, 120 ° C. The drying time can be from about 5 to 20 hours, for example, from about 8 to 12 hours. This provides solid phases which are capable of forming hydrogen peroxide from hydrogen and oxygen by heterogeneous catalysis without noble metals and promoters containing halogen. In the catalyst composition thus prepared, the base metal (M), phosphate (P) and nitrogen (N) may be present in a molar ratio of M: P: N: = 1: 0.9-1.3: 0.9-1.7, for example, in a ratio of 1: 1-1.3: 1.1-1.5 or approximately 1: 1.1-1.2: 1.1-1.5. To prepare the aqueous mixture as described in step a), it gives specific preference to the use of water-soluble base metal salts, such as halides, for example, fluorides, bromides, or chlorides, hydroxides, nitrates, sulfates, cyanides or other salts soluble in water. The use of nitrates is particularly preferred. The base metals used are particularly elements that have atomic numbers 21-32, 39-42 and 48-51. The oxidation state of the metal ion can vary and be, for example, +1, +2, +3, +4, +5, +6, or +7. However, preference is given to the oxidation states in which there are water soluble salts.

According to a particularly preferred embodiment, use is made of the iron salts in the oxidation states +2, +3, +4, +5 or +6, in particular +2 or +3, and tin salts in the oxidation states +2 or +4, in particular +2. It is more preferred to use water soluble iron salts such as iron (III) nitrate and water soluble tin salts such as tin (II) chloride. The phosphate components which can be used according to the present invention are metaphosphoric and orthophosphoric acid and the water-soluble noble metal salts thereof. Particular preference is given to the use of the water-soluble salts of orthophosphoric acid which forms phosphate, acid phosphate or diacid phosphate in aqueous solution. The nitrogen sources which may be employed in accordance with the present invention are nitric acid and noble metal salts, soluble in water thereof. Preferred examples that may be mentioned are water-soluble nitrate salts of the above-mentioned base metals. It is also possible to use ammonia and the noble metal-free salts soluble in water thereof. Primary, secondary or tertiary amines or salts thereof, which are soluble in the solvent used according to the present invention, are also usable. Examples that may be mentioned are lower alkyl amines having up to 3 lower alkyl groups and lower alkyl ammonium salts having up to four lower alkyl groups. Lower alkyl groups are preferably C 1 -C 4 alkyl groups such as methyl, ethyl, n-propyl and n-butyl. The preparation of the metal-containing phosphates containing nitrogen of the present invention is preferably carried out using ammonium or lower alkyl ammonium phosphates. Specific preference is given to the use of diacid ammonium phosphate. According to a specific embodiment of the present invention, iron (III) nitrate and diacid ammonium phosphate produce, after drying, a catalyst composition showing an X-ray diffractogram containing the following characteristic diffraction lines. 2-Theta d 9.37 9.429 18.37 4.824 28.01 3.183 28.78 3.099 35.05 2.558 37.87 2.373 According to another preferred embodiment of the invention, the tin (II) chloride and the diacid ammonium phosphate give, after drying, a catalyst composition which shows an X-ray diffractogram consisting of the following characteristic diffraction lines: 2-theta d 12.79 6.915 13.04 6.784 19.09 4.645 20.21 4.389 23.01 3.861 23.90 3.720 26.18 3.400 30.33 2.944 The previous 2-theta values were determined using copper K (a) radiation (wavelength 1: 1.54056 Angstrom; wavelength 2: 1.54439 Anglestrom).

Other diffraction lines are shown in the attached Figures 1 and 2. According to another preferred embodiment, the catalytically active metal phosphate of the present invention is combined with the oxygen transferrs as another catalytically active component. For this purpose, for example, the generally solid oxygen transfer agent can be suspended in the solution of the aqueous metal salt prepared as described in step a) above and the suspension obtained in this way can, as described above, be evaporated and dried. Although the metal phosphate of the present invention is suitable, in particular, for use in processes for the preparation of hydrogen peroxide, the metal phosphate combined with the oxygen transfer agent is preferably used as a heterogeneous catalyst in organic oxidation reactions, for example , in the epoxidation of olefins. The invention therefore also provides a process for preparing hydrogen peroxide in which hydrogen and oxygen are reacted under conventional conditions in the presence of the metal phosphate of the present invention, and the hydrogen peroxide formed is separated from the catalyst composition. . The invention further provides a process for the epoxidation of olefins, which comprises the reaction of the olefin catalytically in the presence of hydrogen and oxygen. The olefin used can be any organic compound containing at least one ethylenically unsaturated double bond. This may be aliphatic, aromatic or cycloaliphatic in nature, and may have a linear or branched structure. The olefin preferably contains from 2 to 30 carbon atoms. More than one ethylenically unsaturated double bond may be present, for example, as in dienes or threes. The olefin may further comprise functional groups such as halogen atoms, carboxyl groups, carboxylic ester functions, hydroxyl groups, ether bridges, sulfide bridges, carbonyl functions, cyano groups, nitro groups or amino groups. Common examples of these olefins are: ethylene, propene, 1-butene, cis- and trans-2-butene, 1,3-butadiene, pentenes, isoprene, hexenes, octenes, nonenes, tens, undecenes, dodecenes, cyclopentene, cyclohexene, dicyclopentadiene, methylenecyclopropane, vinylcyclohexane, vinylcyclohexene, allyl chloride, acrylic acid, methacrylic acid, crotonic acid, vinyl acetic acid, allyl alcohol, alkyl acrylates, alkyl methacrylates, oleic acid, linoleic acid, linolenic acid, esters and glycerides of these unsaturated fatty acids, styrene, α-methylstyrene, divinylbenzene, indene and stilbene. Mixtures of these olefins can also be epoxidized by the process of the present invention. The process of the present invention is particularly suitable for epoxidation of propene to give propylene oxide. For this purpose, the metal phosphate of the present invention combined with the oxygen transfer agent is advantageously used as a catalyst. Although the metal phosphate component catalyzes the in situ production of hydrogen peroxide, the olefin is epoxidized with the aid of the transfer component. It is economically advantageous to allow the reaction to be carried out only in a pressure range from about 1-20 bar to about 5-70 ° C, in particular at about 20-55 ° C. The molar ratio of H2: 02 can vary in the range from about 1: 1 to about 1:20, in particular from about 1: 1 to about 1:10. Oxygen transfer agents that can be used in the catalysts of the present invention are, for example, titanium silicates having a petasyl structure. As examples of silicates, specific mention is made of those that are crystallographically assigned by X-rays to the MFI or MEL structures or mixed structure MFI / MEL. Zeolites of this type are described, for example, in W.M. Meier, D.H. Olson, "Atlas of Zeolite Structure Types", Butterworths, 2nd edition, 1987. It is also possible to use zeolites containing titanium with the structure of ZSM-48, ferrierite, ZSM-12 or β-zeolite. Instead of titanium, it is also possible, for example, that vanadium is present in the bound form in the zeolite. In the same way, mesoporous oxides containing titanium, vanadium, molybdenum, rhenium or tungsten as described in US 5057296 or DE-A 4407326 can also be used. The above-mentioned particularly preferred titanium silicates having an MFS petasyl structure are prepared by crystallizing a gel for synthesis containing water, a source of titanium and silicon dioxide in a suitable form with the addition of organic, low nitrogen containing compounds. hydrothermal conditions, with or without the addition of a solution of ammonia, alkali or fluoride as a mineralizer. Suitable nitrogen-containing compounds are, for example, 1,6-diaminohexane (see EP 0 007 081) or, preferably, the salts, or the free hydroxide of the tetraalkylammonium salts, such as, in particular, tetrapropylammonium (TPA). ) (see DE-A 3047798). As described in DE-A 4138155, it is possible to avoid the use of expensive TPAOH if TPABr together with ammonia is used instead. This last method in particular avoids the contamination of the silicate of the titanium by alkalis; the alkali content of < 100 ppm is desirable to subsequently obtain a catalyst for sufficiently active epoxidation. The crystallization of the single-phase titanium silicate having the MFI structure is preferably carried out at 140-190 ° C, particularly advantageously at 715 ° C, for a period of about 2 to 7 days, obtaining the product Well crystallized after only about 4 days. Vigorous agitation and a high pH of about 12-14 during crystallization may reduce the synthesis time and the crystallite size differently. The advantageous obtain, for example, primary crystallites having a particle size from 0.05 to 0.5 μ, but in particular less than 0.2 μ. After crystallization, the titanium silicate can be filtered, washed and dried at 100-120 ° C by methods known per se. To remove the amine or the tetraalkylammonium compound still present in the pores, the material can be subjected to another heat treatment in air or with nitrogen. Here it is advantageous to limit the temperature increase to < 550 ° C. The presence of the catalyst functions necessary for the oxidation of the olefin can be verified by IR spectroscopy; at 550 cm "1 and 960 cm" 1 there are significant bands that indicate the presence of the crystallinity in the desired solid state and also the necessary activity of the epoxidation. The titanium zeolites prepared in this manner can, according to a preferred embodiment, be added to the metal phosphates of the present invention. For this purpose, for example, the solution of a metal nitrate and ammonium phosphate can be initially charged and the freshly calcined titanium zeolite can then be added in portions while the stirring is carried out. The zeolite suspension can then be evaporated at about 30-200 ° C, in particular about 50 to 100 ° C, at atmospheric or reduced pressure. To modify the catalyst compositions of the present invention it is possible to employ the methods known from the prior art. Examples that may be mentioned are those formed with the aid of a binder, ion exchange, and / or impregnation with metals, surface modification, for example, by means of DVQ (deposition of chemical vapors) or formation of chemical derivatives, by example, silylation. It can also be considered to deposit the catalyst composition of the present invention on a solid and inert support. Suitable inert supports are, for example, spheres, granules, or extruded aluminum oxide or silicon dioxide. To prepare the supported catalyst composition of the present invention, it is possible, for example, to add the support particles to the aforementioned aqueous metal salt solution before evaporation, if desired together with the above described oxygen transfer agent. and evaporate and dry the mixture as already described. Depending on the organic molecule to be reacted, the catalysts of the present invention can be used in the liquid or gas phase or even in the supercritical phase. In the case of liquid phases, it is preferred that the catalyst be used as a suspension, while in the gas phase or supercritical process a fixed-bed arrangement is advantageous. The deactivated catalysts can be recovered in an active form by controlled combustion of carbon deposits and subsequent reduction, for example, using hydrogen. In the case of a low level of deposits, the catalyst can also be regenerated by a simple washing process. The washing process can be carried out when required at neutral, acid or basic pH. It may also be possible to restore the activity of the catalyst by means of a solution of hydrogen peroxide acidified with mineral acid. The present invention is illustrated by the following examples.

Example 1 Preparation of an iron phosphate catalyst (catalyst A) In a polypropylene beaker, 116 g (0.33 mol) of iron (III) nitrate hexahydrate (Riedel de Haen) were dissolved at room temperature in 250 ml of deionized water and transferred to a one liter glass flask provided with stirring. Separately, 38.3 g (0.33 mol) of ammonium diacid phosphate (NH4H2P04) (Merck) were dissolved at room temperature in 150 ml of deionized water and the phosphate solution formed was added dropwise with vigorous stirring to the nitrogen solution. of iron. The solution thus formed is stirred for another hour at room temperature. The reddish solution is then transferred to a rotary evaporator and evaporated at 90 ° C and 15-20 mbar. The solid obtained is dried overnight at 120 ° C in air in a convection drying oven. The product shows the X-ray diffractogram as shown in Figure 1. The 2-theta values obtained and the associated d-values and the relative intensities for the determined diffraction lines are summarized in Table 1 below.

Peak number = peak number The aforementioned 2-theta values were determined using copper K (a) radiation (wavelength 1: 1.54056 Anglestrdm, wavelength 2: 1.54439 Anglestrom). The catalyst contains 22.2% by weight of iron, 14.0% by weight of phosphorus and 8.3% by weight of nitrogen, which corresponds to a molar ratio of Fe: P: N: of approximately 1: 1.13: 1.5.

Example 2 Use of catalyst A according to the present invention for the catalytic production of hydrogen peroxide from the elements.

A steel autoclave adapted with a glass insert (capacity 25 ml) is charged with the catalyst of Example 1 (100 mg) in 10 ml of methanol and the autoclave is closed. In an explosion-protected facility, hydrogen is fed at 27 ° C with stirring (30 min, 10 ml / min). The pressure is then increased to 40 bar using nitrogen and, finally, oxygen is dosed (100 ml / min). After a reaction time of 4 hours, the autoclave is slowly vented and the content is analyzed. 0.70% by weight of hydrogen peroxide is found by means of iodometric titration. The water content of the reaction product is 3.2% by weight.

Example 3 Preparation of a tin phosphate catalyst (catalyst B) In polypropylene beaker, 54.5 g (0.29 mol) of tin (II) chloride (Merck) are dissolved at room temperature in 250 ml of deionized water and transferred to a 2 1 glass flask provided with stirring. In addition, 38.3 of (0.33 mol) of diacid ammonium phosphate (Merck) are dissolved at room temperature in 950 ml of deionized water and the phosphate solution is added dropwise with vigorous stirring to the tin chloride solution. The suspension formed is adjusted to room temperature for another period of one hour. The mixture is then transferred to a rotary evaporator and evaporated at 90 ° C and 20 mbar and subsequently washed to free it of chlorides using H20. The solid obtained is dried overnight at 120 ° C in air in a convection drying oven. The product shows the X-ray diffractogram as seen in Figure 2. The determined 2-theta values, and the associated d values and relative intensities for the determined diffraction lines are summarized in Table II below.

Table II Peak number = peak number the 2-theta values indicated above were determined using copper K (a) radiation (wavelength 1: 1.54056 Angles, wavelength 2: 1.54439 Angles).

The catalyst contains 37.0% by weight of tin, 11.2% by weight of phosphorus and 5.1% by weight of nitrogen, which corresponds to a molar ratio of Sn: P: N of approximately 1: 1.16: 1.16.

Example 4 Use of catalyst B according to the present invention for the catalytic production of hydrogen peroxide from the elements.

A steel autoclave fitted with a glass insert (capacity 25 ml) is charged with the catalyst of Example 3 (100 mg) in 10 ml of methanol and the autoclave is closed. In an explosion-protected installation, the hydrogen is fed at 27 ° C with stirring (30 min, 10 ml / min). Then the pressure is increased to 40 bar using nitrogen 'and, finally, oxygen is dosed (100 ml / min). After a reaction time of 4 hours, the autoclave is slowly vented and the content is analyzed. 0.38% by weight of hydrogen peroxide is found by means of iodometric titration. The water content of the reaction product is 1.1% by weight.

Example 5 Preparation of a titanium zeolite usable in accordance with the present invention.

A four-necked flask (capacity 2 1) is charged with 455 g of tetraethyl orthosilicate (Merck) at room temperature and 15 g of tetraisopropyl orthotitanate are added with stirring (250 rpm, blade agitator) from the separating funnel. a period of 30 minutes. A clear, colorless mixture is formed. Subsequently, 800 g of a solution of tetrapropylammonium hydroxide (40% TPAOH, alpha, diluted to 20% by weight with deionized water, alkali metal content <10 ppm) is subsequently added and the mixture is stirred for an additional hour. Subsequently, the alcoholic mixture (approximately 460 g) formed by hydrolysis is distilled from 90 ° to 100 ° C. 1.5 l of deionized water are added and the now slightly opaque solution is placed in an autoclave with 2.5 liter capacity. The closed autoclave (200 rpm anchor stirrer) is heated at 3 ° C / min up to a reaction temperature of 175 ° C. After 92 hours the reaction is terminated by cooling. The cooled reaction mixture (white suspension) is centrifuged and the solid is washed several times with water until neutral pH. The solid obtained is dried for 24 hours at 110 ° C (yield 149 g). Subsequently, the template [sic] still present in the zeolite is burned in air by heating at 500 ° C for 5 hours (loss by calcination: 14% by weight). The pure white product has, according to the wet chemical analysis, a titanium content of 1.5% by weight and a residual alkali metal (potassium) content of < 0.01% by weight. The yield is 97% based on the Si02 used. The crystallite size is approximately 0.1-0.15 μ and the product shows typical bands at 960 cm "x and 550 cm -1 in the IR spectrum.

Example 6 Preparation of a catalyst for iron phosphate epoxidation according to the present invention In a polypropylene beaker, 116 g (0.33 mol) of iron (III) nitrate (Riedel de Haen) are dissolved in 250 ml of deionized water as described in Example 1. Separately, 38.3 g (0.33 mol) ) of diacid ammonium phosphate are dissolved in water and the phosphate solution is added with stirring to the initially loaded iron nitrate solution. The pink solution formed is transferred to a rotary evaporator. In addition, a suspension of 7g of titanium silicalite from example 5, in 50 ml of deionized water is added, and the suspension is evaporated for a period of 5 hours as described in Example 1. The catalyst is subsequently dried overnight at 120 ° C. The catalyst contains 10.1% by weight of iron, 6.8% by weight of phosphorus,?% By weight of nitrogen and 1.1% by weight of titanium. Example 7 Preparation of propylene oxide In an explosion-protected facility, a pressurized glass autoclave is charged in 60 ml of an aqueous methanolic solution at 50% concentration. 1 g of the catalyst of example 6 is added thereto. After heating the suspension containing the catalyst in the closed autoclave at approximately 40-50 ° C, nitrogen (30 ml / min), oxygen (30 ml / min), hydrogen (60 ml / min), propene (20 ml / min), are dosed while maintaining a constant pressure of 1 bar. After two hours, the gas stream leaving the reactor contains, according to gas chromatography, a C3 fraction containing 101 ppm of propylene oxide as well as 17.7% by volume of propene and 0.11% by weight by volume of propane. These values are still observed after 6 hours.

After the end of the reaction, 260 ppm of propanediol are also detected in the liquid reaction product.

Comparative Example 1 Influence of the drying temperature on the catalytic activity of the catalysts of the present invention Example 1 was repeated, except that the solid obtained in addition was calcined at 550 ° C in air for 5 hours. The loss by calcination is 58% by weight based on the initial weight of the material. No nitrogen is detected. The product now shows the changed X-ray diffractogram as shown in Figure 3. The determined 2-theta values and the associated d values and the relative intensities of the determined diffraction lines are summarized in Table III below.

Table III Peak number = peak number The aforementioned 2-theta values were determined using copper K (a) radiation (wavelength 1: 1.54056 Angstrom, wavelength 2: 1.54439 Angstrom).

Comparative Example 2 Use of the comparative catalyst without nitrogen for the catalytic production of hydrogen peroxide from the elements.

Example 2 was repeated, but the catalyst of Comparative Example 1 (100 mg) is now initially charged. After a reaction time of 4 hours, the autoclave is slowly vented and the content is analyzed. Only 0.17% by weight of hydrogen peroxide is found by means of iodometric titration. The water content of the reaction product is 2.1% by weight.

Comparative Example 3 Preparation of a phosphate catalyst without a metal component according to the present invention In a polypropylene beaker, 18.9 g (0.3 mol) of boric acid (Merck) are dissolved at room temperature in 250 ml of deionized water and transferred to a 2 1 glass flask provided with stirring. Separately, 38.3 g (0.33 mol) of ammonium diacid phosphate (Merck) are dissolved at room temperature in 950 ml of deionized water and the phosphate solution is added dropwise with vigorous stirring to the boric acid solution. The formed suspension is stirred for another period of one hour at room temperature. The mixture is then transferred to a rotary evaporator and evaporated at 90 ° C / 20 mbar. The solid obtained is dried overnight in air at 120 ° C in a convection drying oven. The catalyst contains 6.1% by weight of boron, 20.7% by weight of phosphorus and 9.6% by weight of nitrogen.

Comparative Example 4 Use of the catalyst for Comparative Example 3 for the catalytic production of hydrogen peroxide from the elements.

Example 2 was repeated, but the catalyst of Comparative Example 3 (100 mg) is now initially charged. After a reaction time of 4 hours, the autoclave is slowly vented and the content is analyzed. Only < 0.01% by weight of hydrogen peroxide is found by means of iodometric titration. The water content of the reaction product is 0.6% by weight.

Claims (2)

1. A noble metal-free catalyst composition obtainable by: a) preparing an aqueous mixture containing: i) a salt of at least one base metal selected from elements having atomic numbers 21-32, 39-42, 48 - 51, 57-75 and 81-83; ii) phosphate ions, and iii) at least one source of nitrogen; and b) evaporating the obtained aqueous solution and drying the catalyst composition thus formed at a temperature of about 30 to about 200 ° C. The composition of the catalyst as claimed in claim 1, wherein the aqueous solution contains metal ions (M), phosphate ions (P) and a nitrogen source (N) in a molar ratio of M: P: N = 1: 0.8-1.4: 0.6-4.0. The catalyst composition as claimed in any of the preceding claims, wherein the salt of the base metal is selected from the water soluble salts of the metals having atomic numbers 21-32, 39-42 and 48-51. The composition of the catalyst as claimed in any of the preceding claims, wherein the source of nitrogen is selected from nitric acid and water soluble salts free of noble metals thereof, ammonium, amines, ammonium or lower alkyl ammonium salts. The catalyst composition as claimed in any of the preceding claims, wherein the nitrogen source is selected from water-soluble ammonium and lower alkyl ammonium salts or a water-soluble nitrate salt of the base metal used and the phosphate component contains diacid phosphate ions. The composition of the catalyst as claimed in any of the preceding claims, wherein the salt of the base metal is selected from among the salts containing iron in the oxidation state +2, +3, +4, +5, and / or +6 and salts containing tin in the oxidation state +2 and / or +4. The composition of the catalyst as claimed in any of the preceding claims, obtainable by evaporation of the aqueous mixture obtained from step a) at a pressure of from about 15 to about 1000 mbar and from about 10 to about 200 ° C, and drying the residue thus obtained from about 30 to 200 ° C. The composition of the catalyst as claimed in any of the preceding claims, wherein the base metal (M), phosphate (P.) and nitrogen (N) are present in the catalytically active dry solid in a molar ratio of M: P: N = 1: 0.9-1.3: 0.9-1.7. The composition of the catalyst as claimed in any of the preceding claims, wherein the metal base component present contains iron ions and the composition shows an X-ray diffractogram containing the following diffraction lines: 2-Theta d 9.37 18.37 4.824 28.01 3.183 28.78 3.099 35.05 2.558 37.87 2.373 or where the metal base component present contains tin ions and the composition shows an X-ray diffractogram containing the following diffraction lines:
2. 2-theta d 12.79 6.919 13.04 6.784 19.09 4.645 20.21 4.389 23.01 3.861 23.90 3.720 26.18 3.400 30.33 2.944 A catalyst composition containing a noble metal-free catalyst component as claimed in any of the preceding claims, as well as an oxygen transfer agent as another catalytically active catalyst. The composition of the catalyst as claimed in claim 10, wherein the oxygen transfer agent is selected from the organometallic compounds, zeolites, zeolite analogues, aluminum phosphate or mesoporous metal oxides which each contain at least one metal that it is selected from among Ti, V, Mo, W, Re and Ru. 12. The composition of the catalyst as claimed in claim 11, wherein the oxygen transfer agent is a titanium or vanadium silicate having a pentasyl structure. 13. The composition of the catalyst as claimed in any of claims 1 to 12 on an inert solid support. 14. A process to prepare hydrogen peroxide, which comprises the reaction of hydrogen and oxygen in the presence of a catalyst composition, as claimed in any of claims 1 to 9. 15. A process for the epoxidation of olefins, which comprises the reaction of the olefin with hydrogen and oxygen in the presence of a catalyst composition as claimed in any of claims 10 to 13.