Catalyst system and method for producing higher alcohols from methanol and ethanol

Abstract

The invention relates to a method for producing C3-C10 monoalcohols from methanol and ethanol using a metal catalyst in the presence of a base, wherein a mixture at least comprising methanol and ethanol is reacted on a carbon-supported metal catalyst at least comprising an alloy of the metals nickel and platinum at a temperature of more than or equal to 100 °C and less than or equal to 200 °C, wherein the molar ratio of nickel to platinum is greater than or equal to 4 and less than or equal to 100,000. The invention additionally relates to a supported metal catalyst and to the use of the catalyst in order to produce C4-C8 monoalcohols from methanol and ethanol.

Description

[0001] Catalyst system and process for the production of higher alcohols from methanol and ethanol

[0002] The present invention relates to a process for the preparation of C3-C10 monoalcohols from methanol and ethanol by means of a metal catalyst in the presence of a base, wherein a mixture at least comprising methanol and ethanol is reacted on a carbon-supported metal catalyst at least comprising an alloy of the metals nickel and platinum at a temperature of greater than or equal to 100 °C and less than or equal to 200 °C, wherein the molar ratio of nickel to platinum is greater than or equal to 4 and less than or equal to 100,000. Furthermore, the present invention relates to a supported metal catalyst and the use of the catalyst for the preparation of C4-C8 monoalcohols from methanol and ethanol.

[0003] Straight-chain or branched alcohols with medium C numbers are important basic chemicals and reactants in the chemical industry, with the increasingly discussed use as fuel or fuel component in gasoline (e.g. i-butanol, 2-butanol, 1-butanol) and / or diesel fuels (1-octanol) making an expansion of capacities seem likely. Based on the availability of relatively short-chain alcohols from biological sources, reactions that synthesize medium-chain alcohols from short-chain alcohols have regained importance in recent years. A well-known reaction is the Guerbet condensation, in which primary or secondary alcohols are converted to longer-chain alcohols via aldehydes and aldol products at high temperatures and high pressure in the presence of alkali metal hydroxides or alkoxides.For this basic reaction, there are a variety of different proposals for the process in the scientific and patent literature.

[0004] For example, US Patent US 2,457,866A describes the synthesis of Guerbet alcohols starting from primary alcohols with at least 4 C atoms in the presence of a base and a hydrogenation catalyst at 120°C to 300°C with azeotropic distillation to remove water of reaction.

[0005] CN 108 043 403 A discloses a synthesis process for a CuO / MgO / M catalyst for the Guerbet reaction. M are oxides selected from the group consisting of Al2O3, ZrO2, TiO2, CeOx, and SiO2. The MgO:CuO:M ratio can be between 100:1-8:5-25. The synthesis involves the preparation of mesoporous MgO using cetylammonium bromide doped with Cu.

[0006] US Pat. No. 2,050,788 A discloses a process for the synthesis of i-butanol by passing methanol and ethanol vapor over an MgO catalyst at atmospheric and superatmospheric pressure and 200-400°C. Increased magnesium oxide activity can be achieved by using Th, Pb, Ag, U, Cd, Sn, Cr, Mn, Zn, Fe, Ni, Co, Cu, their oxides, or mixtures of the aforementioned components. Different mixing ratios of methanol, ethanol, and hydrogen in the reaction are described.

[0007] Such solutions known from the state of the art may offer further potential for improvement, in particular with regard to process control at relatively low temperatures and with regard to a cost-effective and long-lasting catalyst.

[0008] It is therefore the object of the present invention to at least partially overcome the disadvantages known from the prior art. In particular, the object of the present invention is to provide a process that delivers high conversions and selectivities at relatively low temperatures.

[0009] The object is achieved by the features of the respective independent claims, directed to the process according to the invention, the catalyst according to the invention, and the use of the catalyst according to the invention for the synthesis of longer-chain alcohols. Preferred embodiments of the invention are specified in the subclaims, in the description, or in the figures. Further features described or shown in the subclaims or in the description or in the figures may constitute an object of the invention, individually or in any combination, unless the context clearly indicates otherwise.

[0010] According to the invention, a process is accordingly provided for the preparation of C3-C10 monoalcohols from methanol and ethanol by means of a metal catalyst in the presence of a base, wherein a mixture at least comprising methanol and ethanol is reacted on a carbon-supported metal catalyst at least comprising an alloy of the metals nickel and platinum at a temperature of greater than or equal to 100 °C and less than or equal to 200 °C, wherein the molar ratio of nickel to platinum, expressed as molar amount of nickel divided by molar amount of platinum, is greater than or equal to 4 and less than or equal to 100,000.

[0011] Surprisingly, it was found that the reaction according to the invention is characterized by high conversions and selectivities even at low catalyst concentrations. Without being bound by theory, the temperature range in particular appears to be suitable for preventing the formation of unwanted by-products at all or only in small amounts. The process can be operated with widely varying alcohol reactants and ratios and is characterized by long catalyst lifetimes and high space-time yields. Another advantage is that the additional use of hydrogen can be completely dispensed with. It was also found that, in contrast to the mixed metal oxide catalyst systems, which are complex to produce and require high pressures of up to 100 bar during the reaction, an elevated pressure range in the reaction can be dispensed with.In contrast to the previously mentioned state of the art, no expensive rare earths, such as lanthanide oxide, are required. The carbon-rich support material is sufficiently mechanically stable, and this catalyst design results in the catalyst exhibiting a good product formation rate even in the presence of water and producing higher alcohols with high efficiency.

[0012] The process according to the invention is a process for the preparation of C3-C10 monoalcohols from methanol and ethanol. In the process according to the invention, mixtures of short-chain monoalcohols with one or two carbon atoms are converted to monoalcohols with more than two carbon atoms. The medium-chain alcohols can be straight-chain or branched. The reactant mixture used for the synthesis can have varying proportions of ethanol and methanol. The molar ratio of methanol to ethanol can preferably be between 20:1 and 0.5:1, further preferably between 14:1 and 1:1. In principle, the conversion of pure ethanol or pure higher alcohols or mixtures of at least two components of the higher alcohols is also possible using the process according to the invention.Depending on the mixture used, the reaction temperature, and, for example, the residence time, a mixture of alcohols with different C numbers is usually obtained. The isolated pure alcohols are obtainable via conventional separation operations. Products available include propanol, n-butanol, and even decanol. Alcohols with even longer C chains can also be formed, but the selectivity and yield of these even higher alcohols are rather unsatisfactory.

[0013] The reaction mixture comprises at least methanol and ethanol, and the mixture is reacted over a carbon-supported metal catalyst. The reaction of the short-chain alcohols takes place over a metal catalyst, which is not present as such but is bound to a support material. The actual metal catalyst or metal alloy is preferably chemically or physically bonded to the surface or within the support material. The support material can be used in the form of powders or shaped bodies. A suitable shaped body geometry is, for example, spherical or ellipsoidal. The supports can, for example, be present in a single size, monodispersely distributed, or as polydisperse particles.Examples of suitable carbon-containing carrier materials include powdered activated carbon, granulated activated carbon, ordered and disordered mesoporous carbon, carbon black or single- and multi-walled carbon nanotubes or mixtures of at least two components thereof.

[0014] The reaction takes place in the presence of a base. Bases known to those skilled in the art can be used for the catalytic reaction. For example, alkali or alkaline earth hydroxides are possible.

[0015] The metal catalyst comprises an alloy of the metals nickel and platinum. The metal catalyst used does not consist of individual metals, but rather of an alloy comprising at least the metals nickel and platinum. The alloy of these two metals can be produced from the individual metals in different compositions using methods known to those skilled in the art, for example, by thermal treatment. Preferably, the alloy can also consist of nickel and platinum.

[0016] The temperature during the reaction is greater than or equal to 100°C and less than or equal to 200°C. The reaction according to the invention can therefore be carried out within a relatively narrow temperature window and at relatively low temperatures compared to the processes known from the prior art. In particular, this temperature selection can result in a low amount of unwanted by-products and a long catalyst service life. The molar ratio of nickel to platinum in the catalyst, expressed as the molar amount of nickel divided by the molar amount of platinum, is greater than or equal to 4 and less than or equal to 100,000. Within these ratios in the composition of the alloy, very efficient catalysts can be obtained which are characterized by high conversions and good selectivities. The catalysts are mechanically stable and show only a slight loss of activity even after long service times under reaction conditions.Preferably, the molar ratio can also be greater than or equal to 10 and less than or equal to 75,000, and further preferably greater than or equal to 15 and less than or equal to 50,000. The alloy of the metal catalyst can preferably consist of the components nickel and platinum.

[0017] In a preferred embodiment of the process, the molar ratio of nickel to platinum can be greater than or equal to 20 and less than or equal to 100. In the reaction according to the invention, it has proven particularly advantageous for the ratio of the metals used in the alloy to be within the range specified above. Long catalyst lifetimes can be achieved with high selectivity to the longer-chain alcohols and high space-time yields. This composition also has the advantage that the proportion of relatively expensive platinum in the catalyst is very small. This can reduce the process costs of the reaction.

[0018] In a further preferred embodiment of the process, the support material of the carbon-supported metal catalyst can consist of greater than or equal to 75 wt.% amorphous carbon. It has proven very advantageous for the reaction that the support material contains a very high proportion of carbon. This can positively influence the efficiency of the reaction. In particular, the support material of the catalyst can consist of carbon. Surprisingly, it has also been shown that the use of amorphous carbon, without short-range order of the individual carbon atoms to one another, can contribute to improved reactions. A carbon is amorphous carbon if no crystalline phases can be detected in the carbon phase in an XRD measurement with Cu-alpha wavelength under Bragg-Brentano geometry.Crystalline phases for the different carbon materials arise, for example, from significant reflections of graphite (26.6°, 42.3°, 44.5°, 50.7°, 54.7°), diamond (44.0°), C60 (21.0°, 22.0°, 27.7°, 28.4°, 31.2°, 33.1°) and are known to the person skilled in the art.

[0019] Within a further preferred aspect of the process, the support material of the carbon-supported metal catalyst may have an internal surface area, determined by static physisorption of N2, of greater than or equal to 500 m 2 / g and less than or equal to 1300 m 2 / g. The surface area range specified above has proven particularly suitable for conversion efficiency and a long catalyst life under reaction conditions. The surface area of ​​the support can be determined by static physisorption of N2 in a range of p / po = 0.01 to 0.99 at 77.15 K on a Gemini VII from Micromeritics. It is advisable to degas the sample for 1 h at 150°C and 0.007 mbar prior to measurement. Larger surface areas can be detrimental to the catalyst life. Smaller surface areas can lead to insufficient conversion of the starting alcohols.

[0020] According to a preferred process characteristic, the temperature can be greater than or equal to 130 °C and less than or equal to 170 °C. Within this very limited temperature range, a wide variety of methanol / ethanol reactant mixtures can be converted with high conversions and very good selectivity. In addition to the flexibility in the use ratio, the catalyst shows only slight deactivation or deactivation over the reaction time, resulting in very constant space-time yields throughout the conversion.

[0021] In a further preferred embodiment of the process, the mass fraction of the metal alloy in the total mass of the catalyst can be greater than or equal to 3 wt.% and less than or equal to 15 wt.%. Within this mass ratio between active catalyst-metal alloy and carbon-containing support material, mechanically very stable and extremely efficient catalysts can be provided. The catalysts are characterized by high conversions and very good selectivity and exhibit a long service life under reaction conditions. Furthermore, the mass ratio between active catalyst-metal alloy and carbon-containing support material can be greater than or equal to 2.0 wt.% and less than or equal to 14.0 wt.%, further preferably greater than or equal to 3.0 wt.% and less than or equal to 12.5 wt.%.

[0022] Within a preferred aspect of the process, the carbon-supported metal catalyst can have a size distribution with a number-average D05 quantile determined via TEM of greater than or equal to 0.5 nm and less than or equal to 5 nm. Surprisingly, it has been shown that particulate supported catalysts with the above-mentioned size specification contribute to particularly efficient conversions of a large number of different methanol / ethanol mixtures. The supported catalysts show high conversions even at relatively low temperatures and are characterized by long service lives. The D05 quantile can preferably be greater than or equal to 1.0 nm and less than or equal to 4.5 nm, furthermore preferably greater than or equal to 1.5 nm and less than or equal to 4.0 nm. Further preferably, the D09 quantile can be greater than or equal to 5.0 nm and less than or equal to 12.0 nm, furthermore preferably greater than or equal to 6.0 nm and less than or equal to 10.0 nm.

[0023] In a further embodiment of the process, the catalyst concentration can preferably be greater than or equal to 0.7 g / L and less than or equal to 14.5 g / L, preferably greater than or equal to 1.4 g / L and less than or equal to 10.7 g / L, further preferably greater than or equal to 1.42 g / L and less than or equal to 7.5 g / L.

[0024] Furthermore, the invention relates to a metal catalyst, wherein the metal catalyst comprises at least: a) a carbon-containing support material in a weight fraction of greater than or equal to 80 wt.% and less than or equal to 95 wt.%; b) a metal alloy comprising nickel and platinum, wherein the molar nickel fraction of the alloy is greater than or equal to 80% and less than or equal to 99.99% and the molar platinum fraction of the alloy is greater than or equal to 0.01% and less than or equal to 20%; wherein the carbon is amorphous.

[0025] This catalyst is characterized by particularly favorable mechanical properties and high conversion efficiency, particularly for the conversion of ethanol and methanol to longer-chain monoalcohols. For further advantages of the catalyst, particular reference is made to the advantages of the catalyst in the process according to the invention.

[0026] Within a further preferred embodiment of the metal catalyst, the catalyst can have an internal surface, determined by means of static physisorption of N2, of greater than or equal to 500 m 2 / g and less than or equal to 1300 m 2 / g. The surface area range specified above has proven particularly suitable for a particularly balanced catalyst with high conversion efficiency and high mechanical strength. The catalyst is characterized by particularly low mechanical abrasion and minimal catalyst losses during the conversion.

[0027] Furthermore, the invention relates to the use of a metal catalyst according to the invention for the production of C4-C8 monoalcohols from methanol and ethanol. The catalyst claimed according to the invention can be used particularly advantageously in processes in which alcohols with smaller C numbers are converted to alcohols with higher C numbers. For the advantages of using the catalyst, explicit reference is made to the advantages of the process according to the invention. In principle, the reaction can also be carried out with pure ethanol or pure higher alcohols (>C2) or mixtures of the higher alcohols over the catalyst according to the invention by means of the process according to the invention. In a preferred embodiment of the use, the process can be used for the synthesis of i-butanol.For high selectivity to i-butanol in the process according to the invention, a concentration of 0.1 to 2.5 mol / L, but preferably 0.5 to 1.7 mol / L, of ethanol in a methanolic solution can be maintained. At higher ethanol concentrations, more products may be obtained that unintentionally contain a mixture of higher alcohols.

[0028] Examples

[0029] I. Preparation of supported catalysts according to the invention

[0030] Ia Impregnation of a carrier

[0031] To prepare a precursor solution, precursor compounds of nickel and platinum are dissolved in deionized water. Nickel salts in the form of chlorides, nitrates, sulfates, and acetates are suitable for nickel. Free hexachloroplatinic(IV) acid and its sodium and potassium salts, as well as [Pt(NH3)4](NO3)2, are suitable for platinum. The volume of the solution is diluted to match the water absorption capacity of the carbon-rich support material. Approximately 5 g of the carbon-rich support material is mixed with the precursor solution in a vessel and mechanically homogenized. The catalyst precursor is then pre-dried at an elevated temperature of 30–100°C under reduced pressure of 1000–10 mbar for 0.1–4 hours with continuous mechanical mixing.Calcination takes place in an inert gas stream, for example, nitrogen, at a mass flow rate of 0.1-2 g / min and a duration of 1-7 hours at a temperature of 400-700°C. The temperature is then reduced to 100-300°C. At this temperature, a maximum of 50 vol% H2 is added to the inert gas stream for 0.5-2 hours, and the catalyst precursor is treated. After this treatment, an alloy of the metals is formed, and the catalyst precursor is referred to as the catalyst. Lb Impregnation of a carbonaceous support.

[0032] An alternative method for preparing the catalysts is nickel precipitation, followed by impregnation and alloying of Pt onto activated carbon. For this purpose, a 1-0.05 mol / L aqueous solution is prepared using suitable nickel compounds, in which the carbon-rich support material is suspended. Compounds of nickel chlorides, nitrates, sulfates, and acetates are suitable for this purpose. The solution concentration, solution volume, and amount of carbon-rich support material are determined to achieve the desired loading upon complete precipitation. Precipitation is carried out using an aqueous solution of a suitable base such as ammonia, KOH, K2O, BaOH, Ca(OH)2, CaO, Na2O, the sodium, potassium, or ammonium salts of bicarbonate and carbonate, or NaOH. The solution contains a concentration of OH ions of 0.8-0.02mol / L and is added at 0.1-5mL / min while continuously mixing the suspension.During precipitation, the temperature of the suspension is maintained at 20–80°C. The end of precipitation is monitored using a pH electrode and determined at a maximum pH of 12. The suspension is then aged at room temperature with continuous stirring for 0.5–4 hours and filtered. The filter cake is washed with deionized water until the filtrate has a conductivity of <400 pS / cm. The catalyst precursor is then pre-dried at an elevated temperature of 30–100°C under reduced pressure of 1000–10 mbar for 0.1–4 hours with continuous mechanical mixing. The dried catalyst precursor is impregnated with an aqueous precursor solution containing suitable platinum compounds to achieve the desired Ni:Pt ratio. Suitable precursors for this purpose are free hexachloroplatinic(IV) acid and its sodium and potassium salts, as well as [Pt(NH3)4](NO3)2.The catalyst precursor is then pre-dried at an elevated temperature of 30-100°C under reduced pressure of 1000-10 mbar for 0.1-4 hours with continuous mechanical mixing. Calcination is carried out under an inert gas stream at a mass flow of 0.1-2 g / min and a duration of 1-7 hours at a temperature of 400-700°C, and the temperature is then reduced to 100-300°C. At this temperature, a maximum of 50 vol% H2 is added to the inert gas stream for 0.5-2 hours, and the catalyst precursor is treated. After this treatment, the catalyst precursor is referred to as a nickel-platinum alloy catalyst.

[0033] Ic Testing of catalyst activity

[0034] The chemical reaction for testing the catalysts is carried out in an autoclave reactor. The autoclave walls and internals are made of Inconell 600. The autoclave is equipped with an impeller stirrer. The autoclave is loaded with, for example, 0.05–5 g of catalyst with a particle size fraction of d<500 pm, but preferably d<75 pm, and sealed. The atmosphere is exchanged with one or more of the inert gases helium, nitrogen, or argon. 70 mL of the reaction solution is added via a septum. The reaction solution consists of a mixture of methanol (ultrapure, Merck KGaA) and ethanol (ultrapure, Merck KGaA) and deionized water in various concentration ratios, as well as NaOH (ACS, >97%) with a concentration of 0.2–2 mol / L, but preferably 0.4–0.8 mol / L, and n-decane as an internal standard. The reaction is carried out at 150 to 200°C for 4h with a stirrer speed of 1000 rpm and autogenous pressure under nitrogen atmosphere.The time at which the target temperature is reached defines the start of the reaction time. At 30-minute intervals, 3 pL of the reaction solution are quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer.

[0035] II. Examples of implementation

[0036] II.1 Example 1

[0037] 0.25 g of a classified (particle size d<75 pm) commercial platinum catalyst (5% Pt / C, reduced, Alfa Aesar) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is purged with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 120°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 1.

[0038] 11.2 Example 2

[0039] 0.25 g of a classified (particle size d<75 pm) commercial platinum catalyst (5% Pt / C, reduced, Alfa Aesar) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 150°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 1.

[0040] 11.3 Example 3

[0041] 0.25 g of a classified (particle size d<75 pm) commercial platinum catalyst (5% Pt / C, reduced, Alfa Aesar) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 180°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 1.

[0042] 11.4 Example 4

[0043] 0.25 g of a classified (particle size d<75 pm) commercial platinum catalyst (5% Pt / C, reduced, Alfa Aesar) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is purged with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 200°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 1.

[0044] 11.5 Example 5

[0045] 1.2264 g of Ni(NO3)26H2O (>98%, Thermo Scientific) and 0.0049 g of [Pt(NH3)4](NO3)2 (Alfa Aesar) are dissolved in 2.350 g of deionized water. 4.8766 g of activated carbon (Merck KgGaA) are added to the precursor solution in a tightly sealed vessel and homogenized. The catalyst precursor is then pre-dried in a rotary evaporator at 40°C, 6 rpm, and 40 mbar. It is calcined in a tube furnace at 500°C in a nitrogen flow of 0.5 g / min for 4 hours, and the temperature is then reduced to 250°C. At this temperature, 2 vol% H2 is added for 60 minutes, and the catalyst precursor is treated. After this treatment, the catalyst precursor is referred to as the catalyst.

[0046] 0.25 g of the prepared 5% Ni99Pti / C catalyst (particle size d<75 pm) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is purged with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 150°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 1.

[0047] II.6 Example 6

[0048] 0.25 g of the 5% Ni99Pti / C catalyst (particle size d<75 pm) prepared in Example 5 is weighed into the autoclave reactor, and the autoclave is sealed. The atmosphere is purged with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 1.

[0049] No. Catalyst Temperature X(EtOH) / % S(i-Butanol) / %

[0050] 1 5% Pt / C 120 °C 3.89 3.68

[0051] 2 5% Pt / C 150 °C 2,76 88,93

[0052] 3 5% Pt / C 180 °C 3,44 97,70

[0053] 4 5% Pt / C 200 °C 4,85 96,45

[0054] 5 5% Ni99Pti / C 150°C 1,67 99,90

[0055] 6 5% Ni99Pti / C 165°C 4,91 99,90

[0056] Tabelle 1

[0057] Examples 1-6 show that the platinum catalyst (Example 1-4) has a strong tendency toward deactivation, particularly at temperatures above 150°C. This is clearly evident in Table 1, where the i-butanol concentration initially rises sharply but decreases as the reaction progresses. At 180°C (No. 3), the catalyst is inactive for the formation of further i-butanol after just two hours. A comparison of Nos. 2 and 5 shows that the 5% Ni99Pti / C catalyst produces a lower conversion of ethanol. At the same time, the selectivity to i-butanol is increased by 8%. The increase in i-butanol concentration is linear for the 5% Ni99Pti / C catalyst at 150°C, while the Pt / C catalyst already shows a slight decrease in the concentration increase. With No.6, higher ethanol conversions are already achieved than with the 5% Pt / C catalyst at 200°C (No.4).This shows that the 5% Ni99Pti / C catalyst has a higher stability and therefore achieves higher conversions in the same period.

[0058] II.7 Example 7

[0059] 0.25 g of a classified (particle size d<75 pm) commercial platinum catalyst (5% Pt / C, reduced, Alfa Aesar) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 1.2 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 150°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 2.

[0060] 11.8 Example 8

[0061] 0.25 g of a classified (particle size d<75 pm) commercial platinum catalyst (5% Pt / C, reduced, Alfa Aesar) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is purged with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 1.60 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 150°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 2.

[0062] 11.9 Example 9

[0063] 0.25 g of a classified (particle size d<75 pm) commercial platinum catalyst (5% Pt / C, reduced, Alfa Aesar) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 1.96 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 150°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UIDB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 2.

[0064] II.10 Example 10

[0065] 0.25 g of a classified (particle size d<75 pm) commercial platinum catalyst (5% Pt / C, reduced, Alfa Aesar) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 3.02 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 150°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on an Agilent 5977 GC / MS mass spectrometer (Agilent 8890, 122-7032 UIDB-Wax column). The results are listed in Table 2.

[0066] II.11 Example 11

[0067] 0.25 g of a classified (particle size d<75 pm) commercial platinum catalyst (5% Pt / C, reduced, Alfa Aesar) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 3.84 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 150°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on an Agilent 5977 GC / MS mass spectrometer (Agilent 8890, 122-7032 UIDB-Wax column). The results are listed in Table 2.

[0068] 11.12 Example 12

[0069] 0.25 g of a classified (particle size d<75 pm) commercial platinum catalyst (5% Pt / C, reduced, Alfa Aesar) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is purged with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 5.95 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 150°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on an Agilent 5977 GC / MS mass spectrometer (Agilent 8890, 122-7032 UIDB-Wax column). The results are listed in Table 2.

[0070] 11.13 Example 13

[0071] 0.25 g of a classified (particle size d<75 pm) commercial platinum catalyst (5% Pt / C, reduced, Alfa Aesar) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 10.11 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 150°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 60-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UIDB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 2.

[0072] 11.14 Example 14

[0073] 1.0544 g of Ni(NO3)26H2O (>98%, Thermo Scientific) and 0.0739 g of [Pt(NH3)4](NO3)2 (Alfa Aesar) are dissolved in 2.0106 g of deionized water. 4.5000 g of activated carbon (Merck KgGaA) are added to the precursor solution in a tightly sealed vessel and homogenized. The catalyst precursor is then pre-dried in a rotary evaporator at 40°C, 6 rpm, and 40 mbar. Calcination is carried out in a tube furnace at 500°C in a nitrogen flow of 0.5 g / min for 4 hours, and the temperature is then reduced to 250°C. At this temperature, 2 vol% H2 is added for 60 minutes, and the catalyst precursor is treated. After this treatment, the catalyst precursor is referred to as the catalyst.

[0074] 0.25 g of the prepared 5% NigsPts / C catalyst (particle size d<75 pm) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is purged with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 2.0 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 μL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 2. 11.15 Example 15

[0075] 0.25 g of the 5% NigsPts / C catalyst (particle size d<75 pm) prepared in Example 14 is weighed into the autoclave reactor, and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The reaction solution contains ethanol (ultrapure, Merck KGaA) as the solvent, 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as the internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 2.

[0076] Table 2

[0077] Examples 7 to 15 demonstrate the dependence of the product distribution on the initial ethanol concentration. At low ethanol concentrations (a high methanol to ethanol ratio), the formation of i-butanol and 2-methyl-l-butanol predominates. Thus, in Examples 7 and 8, the selectivity for i-butanol is 52.91% and for 2-methyl-l-butanol is 25.03%. i-Butanol is formed by double methylation of ethanol with 1-propanol as an intermediate. 2-Methyl-l-butanol is formed from the cross-aldol addition of 1-propanol and ethanol or from the subsequent methylation of 1-butanol, which is formed by the homoaldol condensation and rehydrogenation of ethanol.

[0078] With increasing ethanol concentrations, the rate of homoaldol condensation and rehydrogenation of ethanol increases. Therefore, the selectivity to i-butanol decreases rapidly with slightly increasing ethanol concentrations, from 52.91% (No. 7) to 28.85% (No. 10), while the ethanol concentration has only increased by 0.76 mol / L (+63%). Therefore, 1-butanol and its homoaldol condensation product, 2-ethyl-1-butanol, are already formed in Example 9. Alternatively, 2-ethyl-1-butanol could also be formed from the heterocondensation of ethanol with 1-butanol. This trend is further illustrated in the following examples. So that finally at a concentration of 10 mol / L ethanol (Me- tOH:EthOH = 1 : 1) 1-octanol can already be formed.

[0079] For Examples 14 and 15, the 5% Ni 95 Pt 5 / C catalyst was used at 165°C. No. 14 is comparable to No. 10 in terms of ethanol concentration. It can be seen that the 5% Ni 95 Pt 5 / C catalyst exhibits a higher selectivity to i-butanol than the Pt / C catalyst at higher ethanol concentrations. At the same time, at ethanol concentrations of 2 mol / L, 1-hexanol is formed with a selectivity of 14.22%. 1-Hexanol can only be formed by the nucleophilic addition of ethanol (or acetaldehyde) to 1-butanol (or butanal). This is noteworthy because the more highly substituted alcohol normally represents the better nucleophile, and therefore the formation of 2-ethyl-1-butanol should occur preferentially. The 5% NigsPts / C catalyst thus shows a higher selectivity to linear coupling products than the commercially available 5%Pt / C catalyst.

[0080] 11.16 Example 16

[0081] 1.2388 g of Ni(NO3)2 6H2O is dissolved in 42.59 g of deionized water and suspended in 4.75 g of activated carbon. Using a Metrohm Titrando 808, the solution is quantitatively precipitated with sodium hydroxide solution (0.1 mol / L, ACS, >97%, addition rate = 0.5 mL / min) while stirring at room temperature. The mixture is aged for one hour and filtered. The filter cake is washed with deionized water until the filtrate has a conductivity of <400 pS / cm. The catalyst precursor is then pre-dried in a rotary evaporator at 40°C, 6 rpm, and 40 mbar. 0.0049 g of [Pt(NH3)4](NO3)2 is dissolved in 0.8997 g of deionized water and impregnated onto the nickel-loaded catalyst precursor. The impregnated catalyst precursor is pre-dried in a rotary evaporator at 40°C, 6 rpm, and 40 mbar. It is calcined in a tube furnace at 500°C for 4 hours at a nitrogen flow of 0.5 g / min, and then the temperature is reduced to 250°C.At this temperature, 2 vol% H2 is added for 60 minutes, and the catalyst precursor is treated. After this treatment, the catalyst precursor is referred to as the catalyst.

[0082] 0.25 g of the prepared 5% Ni99Pti / C catalyst (particle size d<75 pm) is weighed into the autoclave reactor and the autoclave is sealed. The atmosphere is purged with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 1.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 150°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 3.

[0083] 11.17 Example 17

[0084] In contrast to Example 5, 0.25 g of the 5% Ni99Pti / C catalyst (particle size d<75 pm) prepared according to Example 5 is weighed into the autoclave reactor without prior treatment with hydrogen, and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 1.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 150°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 3.

[0085] 11.18 Example 18

[0086] 0.25 g of the 5% Ni99Pti / C catalyst (particle size d<75 pm) prepared according to Example 5 is weighed into the autoclave reactor after treatment with hydrogen, and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 1.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 150°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 3.

[0087] 11.19 Example 19

[0088] 0.25 g of the 5% Ni99Pti / C catalyst (particle size d<75 pm) prepared according to Example 5 is weighed into the autoclave reactor after treatment with hydrogen, and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 3.

[0089] 11.20 Example 20

[0090] 2.3972 g of Ni(NO3)26H2O (>98%, Thermo Scientific) and 0.0322 g of [Pt(NH3)4](NO3)2 (Alfa Aesar) are dissolved in 2.0257 g of deionized water. 4.4977 g of activated carbon (Merck KgGaA) are added to the precursor solution in a tightly sealed vessel and homogenized. The catalyst precursor is then pre-dried in a rotary evaporator at 40°C, 6 rpm, and 40 mbar. Calcination is carried out in a tube furnace at 500°C in a nitrogen flow of 0.5 g / min for 4 hours, and the temperature is then reduced to 250°C. At this temperature, 2 vol% H2 is added for 60 minutes, and the catalyst precursor is treated. After this treatment, the catalyst precursor is referred to as the catalyst.

[0091] After treatment with hydrogen, 0.25 g of the prepared 10% Ni99Pti / C catalyst (particle size d<75 pm) is weighed into the autoclave reactor, and the autoclave is sealed. The atmosphere is purged with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 3.

[0092] 11.21 Example 21 - TI -

[0093] 4.7944 g of Ni(NO3)26H2O (>98%, Thermo Scientific) and 0.0645 g of [Pt(NH3)4](NO3)2 (Alfa Aesar) are dissolved in 1.8006 g of deionized water. 4.0066 g of activated carbon (Merck KgGaA) are added to the precursor solution in a tightly sealed vessel and homogenized. The catalyst precursor is then pre-dried in a rotary evaporator at 40°C, 6 rpm, and 40 mbar. Calcination is carried out in a tube furnace at 500°C in a nitrogen flow of 0.5 g / min for 4 hours, and the temperature is then reduced to 250°C. At this temperature, 2 vol% H2 is added for 60 minutes, and the catalyst precursor is treated. After this treatment, the catalyst precursor is referred to as the catalyst.

[0094] After treatment with hydrogen, 0.25 g of the prepared 20% Ni99Pti / C catalyst (particle size d<75 pm) is weighed into the autoclave reactor, and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UIDB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 3.

[0095] 11.22 Example 22

[0096] 7.1916 g of Ni(NO3)26H2O (>98%, Thermo Scientific) and 0.0967 g of [Pt(NH3)4](NO3)2 (Alfa Aesar) are dissolved in 1.5756 g of deionized water. 3.5007 g of activated carbon (Merck KgGaA) are added to the precursor solution in a tightly sealed vessel and homogenized. The catalyst precursor is then pre-dried in a rotary evaporator at 40°C, 6 rpm, and 40 mbar. It is calcined in a tube furnace at 500°C in a nitrogen flow of 0.5 g / min for 4 hours, and the temperature is then reduced to 250°C. At this temperature, 2 vol% H2 is added for 60 minutes, and the catalyst precursor is treated. After this treatment, the catalyst precursor is referred to as the catalyst.

[0097] After treatment with hydrogen, 0.25 g of the prepared 30% Ni99Pti / C catalyst (particle size d<75 pm) is weighed into the autoclave reactor, and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UIDB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 3.

[0098] 11.23 Example 23

[0099] 2.1088 g of Ni(NO3)26H2O (>98%, Thermo Scientific) and 0.1478 g of [Pt(NH3)4](NO3)2 (Alfa Aesar) are dissolved in 2.0257 g of deionized water. 4.4948 g of activated carbon (Merck KgGaA) are added to the precursor solution in a tightly sealed vessel and homogenized. The catalyst precursor is then pre-dried in a rotary evaporator at 40°C, 6 rpm, and 40 mbar. It is calcined in a tube furnace at 500°C in a nitrogen flow of 0.5 g / min for 4 hours, and the temperature is then reduced to 250°C. At this temperature, 2 vol% H2 is added for 60 minutes, and the catalyst precursor is treated. After this treatment, the catalyst precursor is referred to as the catalyst. After treatment with hydrogen, 0.25 g of the prepared 10% NigsPts / C catalyst (particle size d<75 pm) is weighed into the autoclave reactor, and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum.The methanolic reaction solution contains 0.6 mol / L ethanol (pure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-min intervals, 3 μL of the reaction solution is quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UIDB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 3.

[0100] 11.24 Example 24

[0101] 4.2126 g of Ni(NO3)26H2O (>98%, Thermo Scientific) and 0.3008 g of [Pt(NH3)4](NO3)2 (Alfa Aesar) are dissolved in 1.8168 g of deionized water. 4.0049 g of activated carbon (Merck KgGaA) are added to the precursor solution in a tightly sealed vessel and homogenized. The catalyst precursor is then pre-dried in a rotary evaporator at 40°C, 6 rpm, and 40 mbar. It is calcined in a tube furnace at 500°C in a nitrogen flow of 0.5 g / min for 4 hours, and the temperature is then reduced to 250°C. At this temperature, 2 vol% H2 is added for 60 minutes, and the catalyst precursor is treated. After this treatment, the catalyst precursor is referred to as the catalyst.

[0102] After treatment with hydrogen, 0.25 g of the prepared 20% NigsPts / C catalyst (particle size d<75 pm) is weighed into the autoclave reactor, and the autoclave is sealed. The atmosphere is purged with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UIDB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 3.

[0103] 11.25 Example 25

[0104] 6.3339 g of Ni(NO3)26H2O (>98%, Thermo Scientific) and 0.4432 g of [Pt(NH3)4](NO3)2 (Alfa Aesar) are dissolved in 1.5710 g of deionized water. 3.5029 g of activated carbon (Merck KgGaA) are added to the precursor solution in a tightly sealed vessel and homogenized. The catalyst precursor is then pre-dried in a rotary evaporator at 40°C, 6 rpm, and 40 mbar. It is calcined in a tube furnace at 500°C in a nitrogen flow of 0.5 g / min for 4 hours, and the temperature is then reduced to 250°C. At this temperature, 2 vol% H2 is added for 60 minutes, and the catalyst precursor is treated. After this treatment, the catalyst precursor is referred to as the catalyst.

[0105] After treatment with hydrogen, 0.25 g of the prepared 30% NigsPts / C catalyst (particle size d<75 pm) is weighed into the autoclave reactor, and the autoclave is sealed. The atmosphere is purged with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution were quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UIDB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table S.

[0106] 11.26 Example 26 (blind test)

[0107] For a blind test, the autoclave reactor is sealed without a catalyst. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 0.6 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 3.

[0108] No. Catalyst c(EtOH) T(Reaction) X(EtOH) mol / L °C %

[0109] 16 5% Ni99Pti / Ckons 1.60 150 1.29

[0110] 17 5% Ni99Pti / C 1.60 150 0.60

[0111] 18 5% Ni99Pti / Cred 1,60 150 0,97

[0112] 19 5% Ni99Pti / C 0,60 165 6,13

[0113] 20 10% Ni99Pti / C 0,60 165 7,65

[0114] 21 20% Ni99Pti / C 0,60 165 9,13

[0115] 22 30% Ni99Pti / C 0,60 165 13,45

[0116] 23 10% Ni95Pt5 / C 0,60 165 18,67

[0117] 24 20% Ni95Pt5 / C 0,60 165 11,62

[0118] 25 30% Ni95Pt5 / C 0,60 165 8,63

[0119] 26 Blindtest 0,60 165 0,47

[0120] Tabelle 3 Nr. Selektivität in %

[0121] Acetal- Ace- 1-Pro- 2-Methyl- 1-Bu- 2-Methyl- 2-Ethyl- dehyd ton panol 1 -propanol tanol 1 -butanol 1 -butanol . pentanol

[0122] 16 - 1,11 1,89 85,88 - 11,12

[0123] 17 - - 4,37 52,95 5,90 21,74 15,03

[0124] 18 - 2,95 3,10 77,59 - 16,36

[0125] 19 - 1,66 1,14 97,20

[0126] 20 0,30 1,25 1,17 93,05 - 4,22

[0127] 21 - 0,67 1,63 90,66 - 5,18 - 1,86

[0128] 22 0,44 1,24 1,34 92,94 - 4,05

[0129] 23 -- -- 2,23 90,73 - 5,46 - 1,59

[0130] 24 -- 0,55 2,12 91,40 - 5,93

[0131] 25 -- -- 3,48 84,84 - 8,54 - 3,14

[0132] 26 - - - 27,88 - 72,12

[0133] Examples 16 to 18 demonstrate the influence of different pretreatment methods on catalyst activity under otherwise identical reaction conditions. Example 16 shows a catalyst obtained by precipitation and subsequent impregnation according to Method 2. Compared to Example 18, this results in 85% selectivity to i-butanol and 1.3% ethanol conversion. The 5% Ni99Pti / Cred catalyst from Example 18, in contrast, produces only 0.97% ethanol conversion with a selectivity of 77.59% to i-butanol. A comparison of Examples 17 and 18 clearly shows that reduction in a hydrogen stream has a beneficial effect on the catalyst in Example 18. Thus, the ethanol conversion can be increased by 0.37% and the selectivity to i-butanol by 24.64% compared to the catalyst not treated in the hydrogen stream (No. 17).

[0134] Increasing the reaction temperature results in an increase in ethanol conversion of 5.16% with identical catalysts (No. 18 and No. 19). More important, however, is the significant improvement in i-butanol selectivity by 20% to 97.2%. Examples 19 to 22 show that catalyst loading has a significant influence on ethanol conversion. For example, at 30% loading, an ethanol conversion of 13.45% can be achieved. However, the very good selectivity of 97.2% (No. 19) is slightly reduced by 4%.

[0135] In Examples 23 to 25, an equivalent catalyst with a Ni:Pt ratio of 95:5 is compared to Examples 20 to 22. The highest ethanol conversion is achieved with 10% Ni / Pt / C (No. 23). An ethanol conversion of 18.67% is accompanied by a selectivity of 90.73% to i-butanol. This catalyst thus exhibits a yield far superior to the Pt catalyst due to the higher catalyst stability and activity.

[0136] 11.27 Example 27

[0137] 0.25 g of the 5% NigsPts / C catalyst (particle size d<75 pm) prepared in Example 14 is weighed into the autoclave reactor, and the autoclave is sealed. The atmosphere is purged with nitrogen. 70 mL of the reaction solution is added via a septum. The aqueous reaction solution contains 12.0 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 4.

[0138] 11.28 Working Example 28: 0.25 g of the 5% NigsPts / C catalyst (particle size d<75 pm) prepared in Working Example 14 is weighed into the autoclave reactor, and the autoclave is sealed. The atmosphere is replaced with nitrogen. 70 mL of the reaction solution is added via a septum. The methanolic reaction solution contains 12.0 mol / L ethanol (ultrapure, Merck KGaA), 0.45 mol / L NaOH (>97%, Acros Organics), and 0.015 mol / L n-decane (99%, Acros Organics) as an internal standard. The reaction is carried out at 165°C for 4 h with a stirrer speed of 1000 rpm and autogenous pressure under a nitrogen atmosphere. At 30-minute intervals, 3 pL of the reaction solution was quantitatively analyzed using the headspace method (full evaporation) on a GC-MS (Agilent 8890, 122-7032 UI DB-Wax column) with an Agilent 5977GC / MSD mass spectrometer. The results are listed in Table 4.

[0139] No. Solvent X(EtOH) _ Selectivity in % _ n / Acetalde- , _ , 2-Methyl-l- . ,

[0140] % . . 1 -Propanol . 1 -Butanol hyd propanol

[0141] 27 Wasser 18,56 3,24 - 0,10 23,43

[0142] 28 Methanol 8,07 1,90 0,34 0,40 40,75

[0143] Tabelle 4

[0144] Nr. Selektivität in %

[0145] 2-Methyl-l- 2-Ethyl-l-bu- 2-Methyl-l- 1-Hexa- 2-Ethyl-l- 1-Oc- butanol tanol pentanol nol hexanol tanol

[0146] 27 - 13,78 - 1,44 7,31 4,15

[0147] 28 9,41 11,12 0,14 1,64 5,46 2,91

[0148] Examples 27 and 28 demonstrate the outstanding stability of the catalyst under aqueous conditions. Since no methanol is present in No. 27, no methylation products are formed, whereas in No. 28, these are formed to a lesser extent because, as already explained, the initial ethanol concentration is crucial for product selectivity. As can be seen from the good conversion of 18%, the catalyst is a water-tolerant catalyst. Thus, with the NiPt catalyst, yields of 18.67% i-butanol were obtained at 165°C in 4 h (optimized composition), while the maximum yield of i-butanol with the Pt catalyst was only 4.68% (at 200°C, 4 h, No. 4). Overall, the experiments demonstrate that a stable and economical catalyst is present, which delivers better results than the state-of-the-art catalysts. The catalyst shows a lower deactivation rate compared to 5% Pt / C catalysts.Furthermore, the catalyst is capable of generating good conversions even in aqueous solutions. The Pt content is drastically reduced compared to the 5% Pt / C catalyst, and the catalysts listed are easy to prepare. Furthermore, a process is proposed that, depending on the initial methanol / ethanol ratio, is capable of producing a wide range of products for the chemical industry or, after simple separation steps, a base fuel. This synthesis is highly tolerant to water, thus facilitating the purification of the process media.

Claims

Patent claims 1. A process for the production of C3-C10 monoalcohols from methanol and ethanol using a metal catalyst in the presence of a base, characterized in that a mixture comprising at least methanol and ethanol is reacted on a carbon-supported metal catalyst comprising at least an alloy of the metals nickel and platinum at a temperature greater than or equal to 100 °C and less than or equal to 200 °C, wherein the molar stoichiometric ratio of nickel to platinum, expressed as molar amount of nickel divided by molar amount of platinum, is greater than or equal to 4 and less than or equal to 100,000.

2. The method of claim 1, wherein the molar stoichiometric ratio of nickel to platinum is greater than or equal to 20 and less than or equal to 100.

3. A method according to any of the preceding claims, wherein the support material of the carbon-supported metal catalyst consists of amorphous carbon to a greater than or equal to 75 wt.%.

4. Method according to any of the preceding claims, wherein the support material of the carbon-supported metal catalyst has an internal surface area, determined by static physisorption of N2, of greater than or equal to 500 m² 2 / g and less than or equal to 1300 m 2 / g 5. Method according to any of the preceding claims, wherein the temperature is greater than or equal to 130 °C and less than or equal to 170 °C.

6. Method according to any of the preceding claims, wherein the mass fraction of the metal alloy in the total mass of the catalyst is greater than or equal to 3 wt.% and less than or equal to 15 wt.%.

7. A method according to any of the preceding claims, wherein the carbon-supported metal catalyst has a size distribution with a number-averaged D05 quantile determined by TEM of greater than or equal to 0.5 nm and less than or equal to 5 nm.

8. Metal catalyst comprising at least: a) a carbon-containing support material in a weight fraction greater than or equal to 80 wt.% and less than or equal to 95 wt.%; b) a metal alloy comprising nickel and platinum, wherein the molar nickel content of the alloy is greater than or equal to 80% and less than or equal to 99.99% and the molar platinum content of the alloy is greater than or equal to 0.01% and less than or equal to 20%; wherein the carbon is in an amorphous form.

9. Metal catalyst according to claim 8, wherein the catalyst has an internal surface area, determined by static physisorption of N2, of greater than or equal to 500 m² 2 / g and less than or equal to 1300 m 2 / g 10. Use of a metal catalyst according to any one of claims 8 to 9 for the production of C4-C8 monoalcohols from methanol and ethanol.

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