MXPA99010810A - Moulded activated metallic fixed-bed catalyst - Google Patents

Abstract

The invention relates to a moulded, activated metallic fixed-bed catalyst having a pore volume of 0.05-1 ml/g and an outer, activated shell consisting of a sintered, small-particle catalyst alloy as well as optional catalyst promoters. The catalyst alloy has metallurgical phase domains resulting from the production of the alloy. The phase with the greatest volume has a specific interfacial density of more than 0.5&mgr;m-1.

Description

MOLDED CATALYST DB SOLID LIGHT ACTIVATED. DESCRIPTION OF THE INVENTION: The invention relates to a solid molded metal catalyst and activated in the outer layer according to Raney. Activated metal catalysts are known in the chemical art as Raney catalysts. It was used primarily in the form of powders in a large number of hydratations, dehydrations, isomerations and hydrogenation in organic compounds. These po-shaped catalysts are prepared from an alloy of a catalytically active metal, hereinafter referred to as the catalyst, with another alloying component soluble in alkaline material. Nickel, cobalt, copper, or iron are considered as metal catalysts. For component of soluble alloy in alkaline materials it uses predominantly aluminum but also ot other components are usable, especially zinc and silicon its mixtures with suitable aluminum eon. The preparation of these alloys called Ran is carried out especially after the bar glue process. Here first a mixture of the catalytic metal is melted, for example aluminum and then it is squeezed in bar Typical alloy contents in the production scale RE17-: 32124 from 10 to 100 kg per bar or ingot. According to DE-05 2 59 736 the cooling times achievable here are about 2 hours. This corresponds to an average cooling speed of about 0.2 K / s. In contrast, in procedures with rapid cooling (for example, in a dispersion process speeds of 102 to 10ß K / s are achieved.) The cooling rate is particularly influenced by the particle size and the cooling medium (see Materials Science and Technology, RWCHSAN Editor, P.Haasen EJ Krame, Volume 15 (Processing of Meta and Alloys) 1991 VCH Verlag Weinheim, pages 57 to 110) Such a process is used in EP 0 437 788, to prepare powder Raney alloy Here the melt of the alloy volatilizes and cools at a temperature of 50 to 500 ° C above the melting point with water and / or a gas For the manufacture of a catalyst the Raney alloy is firstly ground, Do not precipitate already in the production in the desired powder form Then the aluminum by a bleach treatment or alkaline materials, such as caustic soda, is completely or partially removed. of alloy By leaching from aluminum presents the dust of the alloy a specific surface high between 20 and 100mVg and is in hydrogen adsorbed. The pyrophorous activated catalyst powder and is stored under water, organic solvents op embedded in organic compounds at ambient temperature The powder catalysts have the disadvantage, which can only be put in a bathing process after the catalytic reaction have to be separated by means of a sedimentation and / or complicated filtration of the reaction medium. This is why there are different methods for manufacturing molded bodies, which after leaching from aluminum lead to activated soleil catalytic catalysts. Thus, for example, there are rough pieces, that is, obtainable roughly ground Raney alloys, which can be activated by caustic soda. The leaching activation takes place only in an upper surface layer, whose thickness is adjustable by the leaching conditions. An essential disadvantage of the catalysts produced with this system is the poor mechanical stability of the activated outer layer, since only that outer ca of the catalyst is also catalytically active, it leads the friction wear to a rapid deactivation, then at the best of the cases can only be recovered by a new activation of the deeper layers of the alloy with caustic soda. In the patent application EP 0 648 534 A1, casting Raney metal catalyzed solid bed catalysts are described., which avoids the disadvantages presented above, as for example the poor mechanical stability in an activation in the form of layers. For the manufacture of these catalysts, a mixture of powders of a catalyst alloy and an agglutination agent is used, where the catalyst alloys each contain at least one catalytically active catalyst metal and an alloying component capable of leaching. The metals are used as binder. pure catalyst or mixtures of them, which do not contain any lexiviable compounds. The application of the binding agent in an amount of 0.5-20% by weight is essential, in order to achieve sufficient mechanical stability, after activation After the modeling of the catalyst alloy and the binder with customary modeling aids, pore-forming bodies raw obtained calcined at temperatures lower than 850 ° C Here enters sintering process of finely divided binder medium for the formation of fixed junctions between the individual large of the catalyst alloy. These compounds, in contrast to non-lexivable catalyst alloys, are only on a very small scale, so that a stable mechanical structure remains after activation. However, the aggregate binder has a disadvantage that it is essentially inactive catalytically and with this the number of active centers in activated cap decreases. Furthermore, only the necessarily necessary application of the binding agent only allows a limited variation in the amount of pore formers, and does not endanger the mechanical strength of the molded body. For these reasons also the bulk density d these catalysts, without loss of mechanical strength can hardly be reduced to a value of 1.9 kg / l. This meant a very important economic disadvantage when applying this catalysts in technical process. Especially when using expensive catalyst alloys, for example d-cobalt alloys, the high bulk density leads to an important capital expenditure for each reactor filling, which however is partially compensated by the high and prolonged stabilized activity of these catalysts. In certain cases, the high bulk density of the catalysts also required a reinforced reactor construction. It is therefore the task of the present invention to provide a modeled activated solid metal bed catalyst, which largely avoids the disadvantages indicated by known solid-bed catalysts. This problem is solved by a molten activated solid metal lech catalyst, with a pore volume of 0.05 to 1 ml / g and an external activated layer, consisting of a sintered fine particle catalyst alloy, as well as optionally promoters, where the Catalyst alloy presents metallurgical phase domains resulting from the manufacture of the alloy, whose large phase m volume has a surface area density greater than 0.5 μm '1. In the specific boundary surface density Sv is a characteristic metallographic size, which describes the grain fineness of the alloy phase aggregate and is defined by the following ratio Sv = á. . P.ferjferia (phase) E / m "1] TT Surface (phase) This grain size is introduced for example in US 3, 337, 334 as the complexity index Cl. The specific surface density Sv, defined here, is differentiated of the complexity index given in US 3, 337, 334 only by the proportionality constant 4 / p.The bigger the smaller the corresponding phase domains, a volumetric phase structure is essential for the catalyst according to the invention. As small as possible, such a fae structure occurs when the fa with the largest volume fraction in the alloy has a specific boundary surface density of more than 0. μm -, The limit surface density can be according to US 3, 33 334 obtained by means of a quantitative metalographic investigation. For this purpose, a transverse cutting of a grain of the catalyst alloy was prepared and investigated microscopically. The different phases of the catalyst alloys show in the light microscope already in the polishing especially in corroded or macerated state it contrasts different gray tones. by means of different gray values the structure can be evaluated with the help of an image analysis system supported by automatic PC. The phases that are presented can be identified, by compositional analysis by means of energy dispersive X-ray analysis. For example for a nickel / aluminum alloy with composition of approximately 50% by weight of nickel and 50% by weight of aluminum corresponding to the phase diagram (see A Specialty Handbook "Aluminum and Aluminum Alloys" Editors J. Davis, 3. Edition page 522, 1994) the fas Al3Ni2, Al3Ni as well as Al-Al3Ni2 eutectium were observed. For the characterization of the catalyst alloy, the phase with the largest volume fraction in the alloy was first determined. The specific limit surface density was then preferably obtained by means of modern image analysis procedures for this phase. It was surprisingly found that the application of catalyst alloys with a small volume phase structure, whose maximum in relation to the volume, has a phase surface density of more than 0.5 μm'1, can be prepared according to the invention s addition of a binder. Despite the lack of agglutinate, a stable mechanical structure is built with resistance to carving. In the manufacture of the catalyst, pore formers can be added in larger amounts due to the lack of the binder, than in the catalyst known from the current state of the art. This allows the manufacture of catalyst bodies with a larger pore volume. binder or binder which is largely inert, which does not present at present, and the high pore volume leads catalysts with a high specific volumetric activity. Depending on the kind and speed of the melt cooling, they can, in spite of identical macroscopic compositions, produce different phase structures. When casting into bars, a cough phase structure with large surface domains forms as a rule due to the low cooling rates. If, on the contrary, a rapid cooling is sought, an essentially fine structure is achieved, the cooling speeds required can be easily determined by the technician by corresponding tests. Only small amounts of alloy can be prepared in the bar casting process. For the cooling speeds required, cooling times of the melt temperature to below 700 ° C in less than 2 minutes can be mentioned. Est corresponds to a cooling speed of when 5K / s. It is preferred to apply cooling speeds of plus 10, especially of more than 50 k / s. The powder manufacturing process according to EP 0 437 788 generally provides alloy powder with a suitable phase structure. For the manufacture of the catalyst according to the invention, alloy powders with an average particle size of 10 μm can be used. Furthermore, the bulk density of alloy powder is important for highly active catalysts. Must be in the range between 1.0 and 3 Kg / l. In bulk densities greater than 3.0 kg / l, they become too compact and contain less active catalyst. Bulk densities less than 1.0 Kg / l lead to a failure in the mechanical stability of the catalyst body. U especially high activity of the catalysts can search if the alloy powder has an average grain size greater than 100 μm and a bulk weight less than 1.6 Kg / l. The weight ratio between the fraction of the catalyst and that of the component of the alloy capable of lexivitation the catalyst alloy, as is usual in the Raney alloys, it remains in the region of 20:80 and 80:20. The catalysts according to the invention can influence the catalytic properties to be impregnated with other metals. Objective such impregnation is for example the improvement of the selectivid in a given reaction. Impregnation metals often point as promoters. The impregnation promotion of the Raney catalysts is described by for example in US 4,153,578, in DE-AS 21 01 856, in DE-OS 21 00 and in DE-AS 20 53 799. In principle all alloys can be used. known metal with leachable elements such as aluminum zinc and silicon for the present invention. Suitable promoters are the transition metals of groups Illb to VII VIII and Group Ib of the periodic system of elements such as rare earth metals. They are applied in a quantity of up to 20% in reference to the total weight of the catalyst. Chromium, manganese, cobalt, vanadium, tantalum, titanium, tungsten and / or molybdenum are preferably used. Preferably for the purpose pursued, the constituent fraction of the alloy of the catalyst alloy. On this, promoters with a metallic alloy capable of leaching can be applied. in the form of a separate metallic pol or subsequently added to the catalyst body. The subsequent addition of promoters can be carried out both after calcination and also after activation. In this way an optimal determination of the catalytic properties in the corresponding catalytic process is possible. The catalyst alloy and, where appropriate, the promoter are prepared in the form of powders with the addition of wetting agents and / or flow materials as molding aids, glidants, plasticizers and in the form of pores in a moldable mass. As the slip agents, plasticizers or pore formers, all the usual materials can be used. In the US Pat. Nos. 4, 826,799; US 3,404,551 and US 3,351,495 s mention a multitude of suitable materials. Preferentially waxes are used, such as Wax C mikropulver Pm d Hoechst AG, fats such as magnesium stearate or aluminum polymers containing carbohydrates such as Tylos (methylcellulose). The solid materials of the mixture, in necessary case, are homogenized, with the addition of a moisturizing agent, carefully in suitable kneading mixers. Wetting agents may be water alcohols, glycols, polyether glycols or mixtures thereof. The objective of the homogenization is the preparation of the mixture for the following molding process. It is applicable for example, extrusion, tabletting and compaction. The kind and sequence of the steps of adding the additional materials depends on the molding process to be used. Thus, the extrusion requires a plastic mass with a specific viscosity, while the rattle requires a material that can run and can easily be dosed. The technique for this use, such as for example an agglomeration for the formation of a powder capable of running or pouring or the adjustment of the correct viscosity for the extrusion, is routinely determined by the person skilled in the art. Moldings can all be used in the usual manner of the catalysts. For example, depending on the requirements of the application case, they can be extruded, spheres, rings, feeding rings, tablets. The finished molding bodies are dried as long as it is necessary for the constancy of weight at temperatures between 80 and 120 ° and then they are calcined at temperatures below 850 ° C, preferably 200 between and 700 °, in furnaces that work continuously or discontinuous such as rotary tube furnaces, stationary furnace or furnace calciners. Thus the organic addition materials are burned and a corresponding pore system is left in place. The pore structure and pore volume of the catalysts can be varied over wide ranges by a suitable selection and amount of pore-forming additive materials. The final structure that is formed and the volume of pores are also influenced by the particle size of the catalyst alloy powder used and the class of compaction. By a corresponding selection of the mentioned parameters the structure of the mold body can be adjusted to the requirements of the catalytic process considered. In the calcination of the molding body, the particles of the alloy powder are sintered together and provide the molding bodies with a high mechanical stability. and good resistance to carving. Typically the hardness of cylindrical shaped tablets after calcination is between 50 and 400 N (medi radially according to ASTM D-4179-82). In this way, due to the specific limit surface density and with this high reactivity for the reactions of solid bodies, the selected calcining conditions arrive at the formation of a stable porous structure. By comparing the phase structure before and after the calcination, it is captured that the desired solid body reaction only occurs with a negligible decrease in the specific limit surface density. However, the specific limit density remains, however, also in the catalytic bodies d, which are still higher than 0.5 μm 1. For the economical use of the invention, the catalytic pre-steps resulting after the calcination also have great significance. They are still not pyrophoric and can therefore be handled without difficulty as well as transported. The activation can then be performed by the user shortly before use. Storage under water or in organic solvents or inlays and organic compounds is not necessary for the catalyst pre-stages.

Against the finished catalysts, in the pre-stages of the catalyst, a body with a homogeneous composition made from an intimate mixture of particles of the catalyst alloy and optionally one or more promoters which are sintered in a body is treated. porous and mechanically stable mold. Its density depends on the composition of the catalyst alloy depending on the pore volume between 1.0 and 2.5 kg / l. Advantageous are pore volumes between 0.05 to lm / g. Since the catalyst pre-caps are not yet activated, s specific surface is less than 20, as a rule less than 10 m2 / g. The pre-stages of the catalyst consist of more than 99% by weight of the catalyst alloy and the promoters which it may contain. When calcining the previous stage temperatures below 850 ° c negligible fractions of superficial oxides can be formed, which however by the activation of lexiviation are removed and therefore have no influence on the subsequent catalytic properties. After calcination by the leaching of aluminum, the molding bodies are activated with the help of caustic sol. For this, for example, a caustic soda solution at 20% heated to 80 is used. A treatment duration of two hours leads according to the porosity of the calcined molding body to an active layer of approximately 0.1 to mm thick. It has been especially shown that the hardness of the compacted molding body at low pressure is clearly increased by leaching. The following examples serve to further understand the invention. Although only a preferred form of embodiment is exemplified in the examples, it already allows the present invention to the technician to manufacture widely varying activated metal solid catalyst catalysts of the Raney type and to adjust to the corresponding application requirements. As a scale of measurement for the amount of catalytic active centils of the catalysts in some samples, its oxygen uptake was obtained by means of an oxidation programmed at the temperature (TPO). In the case of nickel catalysts, for example, each activated nickel atom accepts an oxygen atom by oxidation. To carry out the TPO, dry from 5 to 10 g d activated catalyst body moistened with water in a U-shaped quartz glass tube (internal diameter); lcm, length of branch 15cm) in a current of nitrogen of 12 with a duration of 17 hours. The furnace was then cooled cautiously with liquid nitrogen at -190 ° C. After reaching a constant reaction temperature, a stream of nitrogen was blown and a nitrogen gas containing 4% by volume of oxygen with an intensity of 101 was conducted on the wheel. h. The analysis of the oxygen content of the sample was carried out with an "Oxinos 100" from Leybold Heraeus, which is based on a paramagnetic measuring principle. After reaching a constant oxygen content of approximately -120 ° C, a temperature ramp was established. 6o / minute. The profile of the oxygen intake was captured in the temperature range from -100 ° to + 550 ° C. The amount of oxygen accepted or absorbed was obtained from the surface under the profile of the oxygen intake. The amount of oxygen absorbed is given in mmol 02 / g of catalyst. For the manufacture of catalysts according to the invention, the alloys A to E indicated in Table 1 are used. These alloy powders were cooled in melt-making, in a particularly fast manner and therefore have a phase structure of a very small volum. In the preparation of a comparative catalyst, an alloy powder V was used, where it is used as a standard material for the fabrication of metal activated catalyst catalysts and metallic solid-bed catalysts. The determination of the specific limi surface density Sv is very complicated and only the alloy powders V and A and in a reference sample were obtained exactly here. The surface density of the alloy powder B to E was determined qualitatively by comparison with the reference sample. For the manufacture of the reference sample, 100 g of coarsely cracked pieces of NiAl-V alloy (Table 1) were melted and 4 barrels with a diameter of 7 cm and a length of 15 cm were cast. A high cooling speed could be achieved by the gr surface of the bars. The cooling time of these bars from the melt temperature to less than 700 ° C for about 1 minute. With the quantitative metallography already described, it measured for the Ni2Al3 phase of this reference sample a volumetric fraction of 67.4% and a specific limit surface density of 0.5 μm. "1 For the estimation of the deficits euperficialee limit of alloys B to E prepared intakes microscopic light transverse beam with an increase of 200 to 500 times and compared with corresponding reference shots of the reference sample.

TABLE 1: alloy powder.

EXAMPLE OF COMPARISON 1: According to the proposition of EP 0 648 534 A for a comparison catalyst, from 1000 gd alloy powder V, 150 g Ni powder (more than 99% Ni; ds0 = 21 μm; 5 by weight in reference to the alloy powder used) and 25 g Ethylenebis stearoylamide (2.13 5 by weight in reference to the total metal content) with addition of about 150 gd water a catalyst mixture capable of forming tablets that easily runs, From this mixture, tablets were made by pressure with a diameter of 4 mm and a height of 4 mm. The calcination of the mold bodies was carried out for 2 h at 700 ° C. After calcination the average weight of one tablet was 193.4 mg. The tablets were after l calcification activated in caustic soda at 20% 2 h at 80 ° C. The average thickness of the activated layer, determined with a light microscope, was 0.2 m. The oxygen uptake of the catalyst determined as a measure for the number of active nickel centers was determined by means of TPO and remained at 1.04 mmol of 02 / g in the catalyst. EXAMPLE 1 From 1000 g of alloy powder A and 21.3 g of Ethylene glycosteroyl amide (2.13% in peeo in reference to the total metal content) ee manufactured a tabletable catalyst mixture and capable of running easily. From this mixture, 1 tablet were activated analogously to the comparison example. The average weight of a tablet after the calcination was only 157.3 mg. In a duration d activation equal the average thickness of the activated layer was 0.47 mm. The oxygen uptake of the finished catalyst was 2.16 mmol of catalyst 02 / g. EXAMPLE 2: From a lOOOg of powder of alloy B and 21. ethylene bis stearoyl amide (2.13% by weight with reference to total metal content), a tablettable catalyst mixture capable of running or flowing easily was obtained. From this mixture they manufactured analogously to the tablet comparison example activated. The average weight of a tablet after calcination was 185.5 mg. With equal duration of activation, the average thickness of the activated layer was 0.65mm. With the same grain fraction of the alloy powder, after the addition of aglutinant no stable molded bodies can not be obtained after activation EXAMPLE 3: From 1000 g powder of alloy C and 21.3 gd of ethyl bis stearoyl amide a Tableteable catalyzed mixture able to run easily. From this mixture, analized tablets were prepared analogously to the comparison example. The average weight of a tablet was 167.7 mg. With equal duration of activation was the average thickness of the activated layer of 0.3mm.

COMPARATIVE EXAMPLE 2: For a comparison catalyst according to EP 0 648 534 A1, 100 g of powder of alloy C, 15 g of Ni powder (more than 99% Ni, d 50 = 21 μm, 15% by weight) were prepared. reference to the alloy powder used) and 25 g etielenbis ethearoyl amide (2.13% by weight in reference to the total metal content) a catalyst mixture capable of flowing easily. Activated tablets were manufactured from this mixture analogously to comparison example l. The average weight of a tablet was 167.7 mg. With the same duration of activation, the average thickness of the activated layer was 0. mm. EXAMPLE 4: From 1000 g of powder of alloy D and 43 g of ethylenebisenetearoyl amide 9 4.3% by weight with reference to total metal content), a tabletable catalyst mixture easy to flow or run was manufactured. From this mixture, analogously to the comparison example 1 activated tablet was prepared. The average weight of a tablet after the calcination was 168.9 mg. With the same duration of activity was the average thickness of the activated layer of 0. 3mm. From an alloying powder with an identical macroscopic composition, but with a specific surface density of less than 0.5μm.1, they can not have the same amount of ethylenebis stearoyl amide obtained no stable molding bodies after activation. EXAMPLE 5: From 1000 g of C-alloy powder and 43 gd ethylene bis-stearoyl amide 9 4.3 wt.% With reference to total metal content) a tabletable catalyst mixture capable of flowing easily was obtained. From this mixture they were manufactured analogously to the example of comparison 1 tablet activated. The average weight of a tablet after the calcination was only 186.5 mg. With the same duration of activation, the average thickness of the activated layer was 0.35mm. EXAMPLE OF APPLICATION 1; The catalysts of the comparison examples 1 2 as well as of the examples 1 to 3, were compared as regards their catalytic activity with each other, in the hydrogenation of nitrobenzene. For this, they were put in an agitació autoclave with a gasification stirrer with a capacity of 0. 1, 100 g of nitrobenzene and 100 g of ethanol. In the agitation autoclave, 10 g of catalyst that had been investigated was suspended in such a manner by means of a catalyst canister that the molded body of the catalyst was rinsed well by the educt / solvent mixture and applied with hydrogen. . The hydrogenation was carried out with a hydrogen pressure of 40 bar and a temperature of 150 °. The starting temperature of the ignition spark and the speed of absorption of the hydrogen were obtained. For the control they extracted each time after 1, 2, 3, 4 and 5 hours of reaction samples and were analyzed by gas chromatographs TABLE 2. Hydration of nitrobenzene to aniline The results shown in Table 2 indicate that the catalysts B 1 and B2 (examples 1 and 2) or B3 show comparison with the examples VB 1 or VB 2 (examples d comparison 1 and 2) an essentially increased activity in the hydrogenation from nitrobenzene to aniline. The small activity of the comparison catalyst can be attributed to the low metal content activated by the application of largely inert binder. EXAMPLE OF APPLICATION 2: In a tubular reactor (d = 25.4 mm, 1 = 295 mm) and hydrogen with 25 ml of the catalyst of Comparative Example 1 or Example 1, isopropanol in flowing phase acetone. hydrogenation started with a hydrogen pressure of 5 bar, 70 ° C and an LHSV of 0.2 h'1. In the course of the investigation, LHSV rose by 0.2 to 1.2 h "1, the temperature was exotherm to approximately 80 ° C. After 20 h, a sample was taken and the reaction and the selectivity of the isopropanol were investigated ( Table 3): Table 3: Hydration of acetone to isopropanol The catalyst according to the invention has under the same reaction conditions an insignificantly higher activity when compared or a slightly better selectivity. From the examples of application 1 and 2, catalyst according to the invention is suitable for hydrogenation of nitro group, hydrogenation of imines, hydrogenation of nitriles, hydrogenation of CC double bond, triple bond, hydrogenation of compounds carbonyl hydrogenation of CO, C02 and dream mixtures, the hydrogenation of sugars and the hydrogenation of aromatic rings.

It is obtainable by the manufacture of a mixture from the powders at least one catalyzed alloy with a phase structure of small volume, which because a quantitative metallographic investigation has a surface density of the volumetric phase greater than 0.5μm and if necessary contains one or more promoters, wherein the catalyst alloys each time contain a catalytically active catalyst and at least one alloy component capable of being treated by leaching. By addition of wetting agents and / or flow materials, pre-casting agents, glidants, pore-forming plasticizers, a homogenized mixture is produced and the desired bodies are molded. After calcination of the molding body and activation of the catalyst pre-stages by partial leaching of the alloying components capable of undergoing leaching, as well as final washing, the finished catalyst is obtained.

It is noted that in relation to this date, the best method known by the applicant to carry out the invention, is the conventional one for the manufacture of the objects to which it refers.

Having described the invention as above, the content of the following is claimed as property.

Claims (4)

1. CLAIMS 1.- Catalyst of solid metallic bed ractiva moldead) with a pore volume of 0.05 to lml / g and an external active ca consisting of a finely divided catalytic alloy as well as if necessary promoters, where alloy of the catalyst presents metallurgical domains resulting from the preparation of the alloy whose larger phase according to the volume has a specific limit surface density of more than 0.5μm.
2. 2. - Metallic solid bed catalyst according to claim 1, characterized in that, it is treated in an alloy of the catalyst or catalyst of an alloy of the metal catalysts nickel, cobalt, copper or iron mixtures thereof with a component that can be subject leaching of the group of aluminum, zinc, eylium or mixtures thereof, especially mixtures of aluminum with zinc silicon, where the catalytic metals and the component are lexiviable to each other in a weight ratio of 80: haeta 20: 80.
3. 3. Catalyst of metal oxide bed according to claim 1, characterized by, as promoter, the transition metals of the groups Illb has VIIb and group VIII and those of group IB of the periodic system of the elements as well as the earth metals are preened. rare in a quantity of up to 20 by weight in reference to the total weight of the catalyst.
4. 4. Use of the catalyst according to one of the preceding claims for the hydrogenation of the nitro groups, the hydrogenation of imines, the hydrogenation of nitrile, the hydrogenation of CC double bonds and CC triple bonds, the hydrogenation of carbonyl compounds, hydrogenation of CO, C02 and their mixtures, 1a hydrogenation of sugars and the hydrogenation of aromatic rings.