Aldehyde hydrogenation catalyst

Abstract

The present invention provides a catalyst that has a high selectivity for alcohol in a reaction for hydrogenating an aldehyde to synthesize an alcohol. The aldehyde is hydrogenated using a catalyst that contains nickel, molybdenum, and sulfur, the nickel content being 5% by mass or more and 40% by mass or less in terms of NiO, the molybdenum content being 0.05% by mass or more and 5% by mass or less in terms of MoO3, the sulfur content being 0.01% by mass or more and 1% by mass or less in terms of SO3, and the number of cations in the molybdenum is 2 or less and the standard deviation of the number of cations is 0.7 or less.

Description

[Technical field]

[0001] The present invention relates to a catalyst for the hydrogenation of aldehydes to synthesize alcohols. [Background technology]

[0002] Catalysts for hydrogenating aldehydes to synthesize alcohols have been known for a long time. For example, Patent Document 1 discloses a reduced nickel catalyst containing one or more selected from magnesium, calcium, barium, strontium, and zirconium in an amount of 3 to 15% as a metal content relative to nickel in a nickel diatomaceous earth catalyst. This document 1 discloses a method for hydrogenating saturated or unsaturated aldehydes using this reduced nickel catalyst to produce the corresponding alcohol. Furthermore, this document 1 describes that in the hydrogenation reaction of aldehydes using a nickel catalyst, side reactions that produce ethers and acetals are a major problem. Furthermore, it is described that these side reactions are promoted by the acid present in the catalyst, and that the side reactions are significantly suppressed by including a basic metal salt in the catalyst. In addition, Patent Document 2 describes that the side reactions are suppressed and the selectivity of alcohol is increased by highly dispersing silica with an alkali metal component fixed on the surface in the catalyst.

[0003] Methods that do not use basic metal components are also known. For example, Patent Document 3 describes that the selectivity to alcohols is improved by using a catalyst in which catalytically active components are supported with a gentle concentration gradient from the surface to the center.

[0004] Thus, in the reaction of synthesizing alcohols by hydrogenating aldehydes, it has been known that the selectivity of alcohols can be increased by changing the acidic properties of the catalyst used or the supported state of the active metal. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 44-17127 [Patent Document 2] JP 2020-163334 A [Patent Document 3] JP 2005-279587 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention solves the problem that in the reaction of hydrogenating an aldehyde to synthesize an alcohol, side reactions occur when using conventional catalysts, resulting in low alcohol selectivity. [Means for solving the problem]

[0007] The present inventors have focused on a catalyst containing nickel, molybdenum, and sulfur, and have discovered that by controlling the number of molybdenum cations to a certain level or less and reducing the variation in this number of cations, a catalyst can be obtained that suppresses side reactions in the reaction of hydrogenating aldehyde to synthesize alcohol, thereby achieving high alcohol selectivity.

[0008] More specifically, the selectivity of alcohol can be increased by hydrogenating an aldehyde using a catalyst that contains nickel, molybdenum, and sulfur, the nickel content being 5% by mass or more and 40% by mass or less, calculated as NiO, the molybdenum content being 0.05% by mass or more and 5% by mass or less, calculated as MoO3, the sulfur content being 0.01% by mass or more and 1% by mass or less, calculated as SO3, and the number of molybdenum cations being 2 or less and the standard deviation of the number of cations being 0.7 or less. Effect of the Invention

[0009] According to the present invention, a catalyst having high selectivity for alcohol in a reaction for synthesizing alcohol by hydrogenating an aldehyde can be provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention includes an invention relating to a catalyst used in a reaction for hydrogenating an aldehyde to synthesize an alcohol (hereinafter, also referred to as "the catalyst of the present invention"). The catalyst of the present invention will be described in detail below.

[0011] [Catalyst of the present invention] The catalyst of the present invention contains nickel, molybdenum, and sulfur. Nickel acts as an active component in the reaction of hydrogenating aldehyde to synthesize alcohol. Molybdenum and sulfur are believed to have the effect of increasing the selectivity of alcohol.

[0012] The nickel contained in the catalyst of the present invention may be any of metal, nickel oxide, or a mixture thereof. Metallic nickel is active in the aldehyde hydrogenation reaction, but metallic nickel is easily oxidized in air to form nickel oxide. Therefore, the nickel contained in the nickel catalyst exists partially or entirely in the form of nickel oxide, and is reduced to metallic nickel with hydrogen or the like before the hydrogenation reaction before use. In addition, metallic nickel can be stably handled even in air by forming an oxide film on its surface or by adsorbing carbon dioxide or the like.

[0013] The nickel content of the catalyst of the present invention is 5 mass % or more and 40 mass % or less in terms of NiO. The nickel content in the present invention is calculated from the following formula. Nickel content [mass%] = (mass of Ni converted to NiO / total mass of catalyst) x 100 The nickel content is preferably 5% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less. The catalyst of the present invention having a nickel content in the above range is likely to have a high alcohol selectivity.

[0014] The molybdenum contained in the catalyst of the present invention may be any of metal, molybdenum oxide, or a mixture thereof. It is believed that molybdenum has the function of increasing the selectivity of alcohol when it exists in a state where a part or all of it coexists with sulfur. In addition, the molybdenum that exists in a state where it coexists with sulfur may exist alone or in the form of a compound.

[0015] The molybdenum content of the catalyst of the present invention is 0.05 mass % or more and 5 mass % or less in terms of MoO3. The molybdenum content in the present invention is calculated by the following formula. Molybdenum content [mass%] = (mass of molybdenum converted to MoO3 / total mass of catalyst) x 100 The molybdenum content is preferably 0.05% by mass or more and 4% by mass or less, and more preferably 0.1% by mass or more and 3% by mass or less. The catalyst of the present invention having a molybdenum content in the above range is likely to have a high alcohol selectivity.

[0016] The sulfur contained in the catalyst of the present invention may be any of molybdenum sulfide, sulfur oxide, or a mixture thereof. Generally, sulfur is known to be a poisonous substance of nickel-containing catalysts. However, in the catalyst of the present invention, it is believed that the presence of part or all of sulfur in a state of coexistence with molybdenum increases the selectivity of alcohol.

[0017] The sulfur content of the catalyst of the present invention is 0.01 mass % or more and 1 mass % or less in terms of SO3. The sulfur content in the present invention is calculated by the following formula. Sulfur content [mass%] = (mass of sulfur converted to SO3 / total mass of catalyst) x 100 The sulfur content is preferably 0.01% by mass or more and 0.5% by mass or less, and more preferably 0.01% by mass or more and less than 0.1% by mass. The catalyst of the present invention having a sulfur content in the above range is likely to have a high alcohol selectivity.

[0018] The catalyst of the present invention has a molybdenum cation number of 2 or less. In the present invention, the molybdenum cation number is an index representing the valence of molybdenum. The molybdenum cation number varies depending on the state of molybdenum and the state of sulfur bonding to the surface of molybdenum. The molybdenum cation number can be measured by energy dispersive X-ray analysis (EDS). The molybdenum cation number in the present invention is determined by observing the surface of the catalyst using a scanning electron microscope energy dispersive X-ray analysis device (SEM-EDS), detecting multiple spots where molybdenum is detected, and averaging the number of molybdenum cations at 15 points. The catalyst of the present invention exists in a state where molybdenum and sulfur coexist, and as a result, the number of cations is 2 or less. The catalyst of the present invention preferably has a molybdenum cation number of 1.75 or less, more preferably 1.5 or less. The lower limit of the molybdenum cation number is not particularly limited, but may be 0 or more, or may be 0.1 or more. In the catalyst of the present invention in which the number of cations is within the above-mentioned range, molybdenum and sulfur are present in large amounts in a coexisting state, and therefore the selectivity for alcohol tends to be high.

[0019] The catalyst of the present invention has a standard deviation of the number of molybdenum cations of 0.7 or less. The standard deviation of the number of molybdenum cations is an index showing the variation in the number of molybdenum cations, and the smaller the value, the smaller the variation. Since the catalyst of the present invention has a small variation in the number of molybdenum cations, the selectivity of alcohol is high. Moreover, the catalyst of the present invention has a number of molybdenum cations of preferably 0.6 or less, more preferably 0.5 or less.

[0020] The specific surface area of ​​the catalyst of the present invention is 50 m 2 / g or more, 250m 2 / g or less, and 2 / g or more, 225m 2 / g or less is more preferable, and 2 / g or more, 200m 2In the catalyst of the present invention having a specific surface area in the above-mentioned range, molybdenum and sulfur tend to coexist, and the selectivity for alcohol tends to be higher.

[0021] When the catalyst of the present invention contains metallic nickel, the crystallite size of the nickel is preferably 10 nm or less, more preferably 2 nm or more and 9 nm or less, and particularly preferably 3 nm or more and 8 nm or less. The catalyst of the present invention having a nickel crystallite size in the above-mentioned range is likely to have a higher alcohol selectivity and is less likely to lose catalytic activity when used continuously.

[0022] The catalyst of the present invention preferably contains a carrier. The catalyst of the present invention, in which nickel, molybdenum, and sulfur are dispersed and supported on the carrier, tends to have a higher alcohol selectivity. The carrier contained in the catalyst of the present invention is preferably at least one or more selected from silica, alumina, silica alumina, and diatomaceous earth.

[0023] The catalyst of the present invention is preferably a molded body. The catalyst of the present invention can be used in the form of a powder in the method for producing alcohol by hydrogenating aldehyde, but the molded body is preferable because it is easy to separate and recover after the reaction. The shape of the molded body may be any shape known in the art. For example, it may be a spherical shape, a cylindrical shape, or a shape similar thereto. The shape of the catalyst of the present invention is preferably a cylindrical shape or a shape similar thereto. The cylindrical shape also includes shapes such as a cylindrical shape, a three-lobed shape, and a four-lobed shape. The shape of the nickel catalyst of the present invention is preferably a cylindrical shape, and the diameter is in the range of 0.5 mm or more and 7 mm or less, and the length is in the range of 1 mm or more and 10 mm or less.

[0024] [Method of producing the catalyst of the present invention] The catalyst of the present invention can be produced, for example, by using a production method including the following steps (1) to (4). (1) A mother liquor preparation step in which nickel and sulfur are dissolved in water to prepare a mother liquor. (2) a precipitation step of adding a precipitant to the mother liquor to form a precipitate containing nickel and sulfur; (3) a molybdenum supporting step of mixing the precipitate with a molybdenum impregnation solution in which molybdenum is dissolved to prepare a catalyst precursor containing nickel, molybdenum and sulfur; (4) A catalysis step of calcining the catalyst precursor to obtain a catalyst. The method for producing the catalyst of the present invention will be described in detail using this production method as an example, but the production method for the catalyst of the present invention is not limited to this production method.

[0025] [Mother liquor preparation process] This step is a step of preparing a mother liquor in which nickel and sulfur are dissolved in water. For example, it can be prepared by a conventionally known method such as a method of dissolving nickel sulfate in water or a method of dissolving nickel in sulfuric acid. The nickel content of this mother liquor is preferably 1% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 15% by mass or less, and particularly preferably 5% by mass or more and 10% by mass or less, calculated as NiO based on the total mass of the mother liquor. The sulfur content of this mother liquor is preferably 1% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 15% by mass or less, and particularly preferably 5% by mass or more and 10% by mass or less, calculated as SO3 based on the total mass of the mother liquor.

[0026] The mother liquor obtained in this step preferably contains a carrier in addition to nickel and sulfur. The carrier is preferably contained in the mother liquor, because nickel and sulfur are dispersed and supported on the surface of the carrier in the precipitation step described later. The carrier that can be used in this step is preferably at least one or more selected from silica, alumina, silica alumina, and diatomaceous earth. The carrier content of this mother liquor is preferably 1% by mass or more and 20% by mass or less, more preferably 1% by mass or more and 10% by mass or less, and particularly preferably 1% by mass or more and 5% by mass or less, calculated as the mass of the carrier when added to the mother liquor relative to the total mass of the mother liquor. By adjusting the carrier content to the above range, the handleability of the mother liquor can be maintained, which is preferable from the viewpoint of productivity.

[0027] The mother liquor obtained in this step is preferably acidic, with a pH of preferably not more than 6. By making the mother liquor acidic, nickel and sulfur can be stably present in a dissolved state in the mother liquor.

[0028] [Precipitation process] This step is a step of forming a precipitate containing nickel and sulfur by adding a precipitant to the mother liquor obtained in the previous step. In this step, a precipitate containing nickel and sulfur is formed in the mother liquor by adding a precipitant to the mother liquor. The mother liquor in which the precipitate is formed is also called a precipitate slurry.

[0029] The precipitant added to the mother liquor in this step can be appropriately selected from among common precipitants depending on the pH of the mother liquor. When the mother liquor is acidic, a basic compound such as sodium carbonate, sodium hydroxide, potassium carbonate, sodium hydroxide, ammonia, or an aqueous solution in which these compounds are dissolved can be used as the precipitant. In this step, the precipitant is preferably added to the mother liquor until the pH of the precipitation slurry obtained by adding the precipitant to the mother liquor is 8.0 or more and 10.5 or less, and more preferably, the precipitant is added to the mother liquor until the pH of the precipitation slurry obtained by adding the precipitant to the mother liquor is 8.0 or more and 10.0 or less.

[0030] In this step, the temperature of the mother liquor is preferably adjusted to a range of 50° C. to 90° C., more preferably 60° C. to 85° C. If the temperature of the mother liquor is adjusted to the above range and a precipitating agent is added, a precipitate in which nickel and sulfur are more dispersed can be formed.

[0031] In this step, it is preferable to age the precipitation slurry. Specifically, it is preferable to age the mother liquor until the pH is -0.20 or less, more preferably until the pH is in the range of -0.20 or less and -0.50 or more, and particularly preferably until the pH is in the range of -0.20 or less and -0.40 or more. This aging can reduce unreacted nickel and sulfur. It is also preferable to adjust the temperature of the precipitation slurry to a range of 50°C or more and 90°C or less, and more preferably to a range of 60°C or more and 85°C or less. If the temperature of the precipitation slurry is adjusted to the above range and aged, the pore volume and specific surface area of ​​the finally obtained catalyst are likely to increase.

[0032] In this step, it is preferable to remove the solvent contained in the precipitation slurry to separate the precipitate. When separating the precipitate from the precipitation slurry, the separation conditions are adjusted so as not to remove too much sulfur. For example, when the solvent is removed by evaporation to dryness or spray drying to separate the precipitate, or when the precipitate is separated by filtration, the washing conditions are adjusted so as not to remove too much sulfur. Sulfur is known to be a poisonous substance for catalysts containing nickel. Therefore, in general, in the manufacturing method of a catalyst containing nickel, careful washing is performed to remove sulfur. However, in this manufacturing method, sulfur is left in the precipitate. If sulfur is removed by separation or washing, it is preferable to support sulfur on the precipitate using an aqueous solution containing a sulfate such as sulfuric acid or ammonium sulfate.

[0033] [Molybdenum loading process] This step is a step of preparing a catalyst precursor containing nickel, molybdenum and sulfur by mixing the precipitate obtained in the above-mentioned precipitation step with a molybdenum impregnation solution in which molybdenum is dissolved.

[0034] In this step, it is preferable to prepare a molybdenum impregnating solution by dissolving a molybdenum compound in water. For example, the molybdenum impregnating solution can be prepared by dissolving a soluble molybdenum compound such as ammonium molybdate or sodium molybdate in water, or by dissolving a poorly soluble molybdenum compound such as molybdenum oxide with an acid. The molybdenum content of the molybdenum impregnating solution is preferably 0.1% by mass or more and 15.0% by mass or less, more preferably 0.5% by mass or more and 10.0% by mass or less, and particularly preferably 1.0% by mass or more and 5.0% by mass or less, calculated as MoO3 mass based on the total amount of the molybdenum impregnating solution.

[0035] In this step, it is preferable to mix a molding aid together with the molybdenum impregnation liquid. In this step, a conventionally known molding aid can be used. For example, inorganic compound binders such as diatomaceous earth, powdered silica, alumina, etc., and sols in which these are dispersed can be used. In addition, organic binders such as polyvinyl alcohol, cellulose, and acrylic can also be used. The type and amount of binder added are appropriately adjusted to conditions suitable for various molding methods. Thereafter, it can be molded by a conventionally known molding method. For example, it is preferable to mold into an optimal shape as a catalyst using a method such as extrusion molding or compression molding.

[0036] [Catalytization process] This step is a step of obtaining a catalyst by calcining the catalyst precursor obtained in the above step. In this step, the nickel compound contained in the catalyst precursor is decomposed by calcination to generate nickel oxide. The calcination temperature required for the decomposition of the nickel compound varies depending on the type of nickel compound. However, if the catalyst is calcined at a temperature of 300°C or higher and 450°C or lower, nickel oxide is generally obtained. However, if the catalyst is calcined at a high temperature, nickel oxide will aggregate and grow. The catalyst with nickel oxide aggregated in this way has a reduced catalytic activity in the reaction of hydrogenating aldehyde to synthesize alcohol. In this step, the catalyst precursor is preferably calcined at a temperature in the range of 350°C or higher and 400°C or lower. In addition, the calcination time is preferably in the range of approximately 1 hour or higher and 24 hours or lower.

[0037] In this step, reduction stabilization treatment may be further performed after the calcination. This reduction stabilization treatment refers to a method in which nickel oxide contained in the catalyst is reduced to metallic nickel and then the surface is covered with an oxide film. By using such a method, even a catalyst containing metallic nickel can be safely handled in air. In addition, pretreatment performed before the reaction of hydrogenating aldehyde to synthesize alcohol becomes easy. For example, a method of reducing nickel oxide to metallic nickel is a method of heating until nickel oxide is reduced while a reducing gas is circulating. However, if the catalyst is heated too much, metallic nickel aggregates and grows, and the crystallite size of metallic nickel becomes large. Therefore, such reduction treatment is preferably performed at a temperature range of 350°C or more and 500°C or less, and more preferably at a temperature range of 380°C or more and 450°C or less. The time required for the reduction treatment varies depending on the amount of catalyst charged. To determine the end of the reduction treatment, the water content of the gas after the reaction may be analyzed. As the reduction treatment approaches the end, the amount of water produced by reduction decreases.

[0038] Since the catalyst after reduction treatment contains metallic nickel, it will oxidize rapidly if it is taken out into the air as it is. In some cases, it may catch fire due to the heat of oxidation. Therefore, it is preferable to slowly oxidize the surface of the catalyst after reduction treatment in an inert gas with a very small amount of oxygen. This type of treatment is also called stabilization treatment. By carrying out this treatment, the catalyst containing metallic nickel can be safely handled even in air. EXAMPLES

[0039] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. [Measurement method or evaluation method] The various measurements and evaluations were carried out as follows.

[0040] [pH measurement] The pH was measured at a liquid temperature of 40° C. using a pH meter (manufactured by Yamagata Toa DKK Co., Ltd., "MM43-X") and a pH electrode (manufactured by Yamagata Toa DKK Co., Ltd., "GST-5841C").

[0041] [Composition Analysis] (Ni, Mo and S) The sample was dissolved in acid and diluted with water to an appropriate concentration, and then the Ni and Mo contents were measured using an ICP optical emission spectrometer (Agilent Technologies, 730ICP-OES, inductively coupled plasma optical emission spectrometry). S was measured by a combustion method. Each content was calculated based on the total amount of catalyst, with Ni calculated as NiO, Mo calculated as MoO3, and S calculated as SO3.

[0042] [Crystallite size measurement] X-ray diffraction measurements were performed on the samples using an X-ray diffractometer (Rigaku MultiFlex) manufactured by Rigaku Corporation. First, the sample to be measured was crushed and packed into a sample plate, and X-ray diffraction (Cu-Kα radiation source) measurements were performed under the following conditions: tube voltage 40 kV, tube current 20 mA, scanning range 10-70°, divergence slit 1.0 mm, scattering slit 1.0 mm, receiving slit 0.3 mm, and scan speed 4° / min. The crystallite size of Ni was calculated by the Scherrer formula using analysis software (JADE Version 5.0) after detecting a diffraction peak with a peak top at 2θ = 44° by X-ray diffraction measurement.

[0043] [Specific surface area measurement] The specific surface area was calculated by the nitrogen adsorption method (BET method). Specifically, using a specific surface area measuring device (Macsorb1220, manufactured by Mountech), about 0.1 g of the sample was placed in a measurement cell, and degassed for 40 minutes at 250°C in a nitrogen gas flow. The sample was then kept at liquid nitrogen temperature in a mixed gas flow of 30% by volume of nitrogen and 70% by volume of helium, and nitrogen was adsorbed into the sample at equilibrium. The temperature of the sample was then gradually raised to room temperature while the mixed gas was being passed through, and the amount of nitrogen desorbed during this period was measured, and the specific surface area of ​​the sample was calculated by dividing the amount by the weight of the sample after measurement.

[0044] <Measurement of the number of molybdenum cations> For SEM measurement, JEOL's JSM6010LA was used, and W was used as the X-ray source. The catalyst obtained in the example was crushed into powder, and these were attached on a carbon tape so as not to overlap, and the catalyst surface was measured. The acceleration voltage was adjusted to 20 kV-15 kV, and SS was set to 4 nm. Then, the image was magnified 2500 to 10000 times, and the analysis position was probe tracked to perform EDS analysis so that the measurement position could be traced, and then composition conversion was performed by the ZAF method. The particle diameter of Mo was calculated from the peak obtained there. After adjusting the beam diameter to this particle diameter, the image was magnified 500 to 10000 times, and the analysis position was probe tracked to adjust so that the measurement position could be traced, and point analysis of S and Mo was measured at 30 points. <Calculation method> From the obtained data, 15 points where Mo was detected were randomly selected, and the number of Mo cations was calculated for each point. The average and standard deviation were calculated using these values. Here, the number of cations was calculated based on the number of oxygen in the fully oxidized state (MoO3 in the case of Mo) being 24, and the number is 0 in the fully oxidized state.

[0045] [Activity evaluation: hydrogenation reaction of aldehydes] <Pretreatment> After 12.0 g of a sample was placed in a glass tube, it was kept at 150° C. for 60 minutes under a hydrogen flow. Then, the atmosphere in the glass tube was replaced with nitrogen and it was cooled to room temperature. Then, the sample was placed in an autoclave in a nitrogen atmosphere. <Hydrogenation test> 50 g of n-butyl aldehyde and 50 g of n-butyl alcohol were injected into the autoclave. After injection, the temperature was raised to 100°C while stirring at 400 rpm. After heating, hydrogen was injected until the pressure inside the autoclave reached 5 MPa, and the pressure was maintained at 5 MPa. During the holding period, the amount of hydrogen absorption was checked every 5 minutes, and the reaction was terminated when no hydrogen absorption was confirmed for 5 minutes. After holding, the reaction liquid was cooled to room temperature to obtain a reaction liquid. <Analysis> The reaction solution obtained was analyzed by gas chromatography (Shimadzu Corporation, GC-14B) to measure the contents of n-butylaldehyde (NBD) and n-butanol (NBA). The NBA selectivity was calculated from the following formula. [NBA selection rate] NBA selectivity (%) = (number of moles of NBA after reaction - number of moles of NBA before reaction) / (number of moles of NBD after reaction - number of moles of NBD before reaction) x 100

[0046] [Example 1] <Mother liquor preparation process> 900 g of nickel sulfate hydrate (NiSO4·6H2O, Fujifilm Wako Pure Chemical Industries, Ltd.) was dissolved in 3,200 g of tap water. Next, 110 g of diatomaceous earth was dispersed therein to prepare a mother liquor. The temperature of this mother liquor was adjusted to 72.5°C. The nickel content of this mother liquor was 6.1% by mass, the sulfur content was 6.5% by mass, and the diatomaceous earth content was 2.6% by mass. The pH of the mother liquor was 5.3.

[0047] <Precipitation process> A precipitant was prepared by dissolving 717 g of sodium carbonate (Na2CO3, Kanto Chemical Co., Ltd.) in 2,780 g of tap water. The temperature of this precipitant was adjusted to 72.5°C. The precipitant was added to the mother liquor obtained in the above-mentioned process at a constant rate over 80 minutes to obtain a precipitation slurry. At this time, the pH of the precipitation slurry was 9.5. After that, the precipitation slurry was aged by stirring for 120 minutes while maintaining the temperature of the precipitation slurry at 72.5°C. At this time, the pH of the precipitation slurry was 9.2. The aged precipitation slurry was filtered under reduced pressure using a Nutsche filter to obtain a cake-like precipitate. The entire amount of the obtained cake-like precipitate was poured into 7 L of warm water adjusted to 40°C, and the precipitate was made into a slurry, and suspension washing and filtration were performed. The same process was repeated, and the sulfur content of the precipitate was adjusted to 0.10 mass% in terms of SO3 based on the mass of the precipitate after drying at 120°C. The precipitate was then dried in a tray dryer for 12 hours at 120° C. After drying, the precipitate was crushed using a hammer crusher mill.

[0048] <Molybdenum Supporting Process> 22.5g of ammonium molybdate tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was dissolved in 800ml of ion-exchanged water to obtain a molybdenum impregnation solution. 341g of the precipitate obtained in the above process, the entire amount of the molybdenum impregnation solution, 1,500g of silica sol (primary particle size 5nm, pH 10, SiO2 content 20.5%, stabilized with sodium hydroxide) as a molding aid, and 1,020g of powdered silica were mixed and kneaded using a twin-arm kneader. Then, 10g of carboxymethylcellulose was added as a molding aid and further kneaded. The clay obtained by kneading was molded into a cylindrical shape of 5.0mmφ using a twin-screw auger extruder. This was dried at 120°C to obtain a catalyst precursor.

[0049] <Catalytic process> 500 g of the catalyst precursor obtained in the above step was heated in a muffle furnace at 380°C for 4.5 hours. The catalyst was obtained by calcining for 10 hours. 250 g of this catalyst was reduced in a hydrogen atmosphere at 430°C for 10 hours and then stabilized at 80°C to obtain a catalyst. This catalyst was used as a sample to carry out the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0050] [Example 2] A catalyst was obtained in the same manner as in Example 1, except that the amount of ammonium molybdate tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) in the molybdenum supporting step was 11.2 g. The catalyst obtained was subjected to the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0051] [Example 3] A catalyst was obtained in the same manner as in Example 1, except that in the molybdenum supporting step, the amount of ammonium molybdate tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was 45.1 g. The obtained catalyst was subjected to the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0052] [Example 4] A catalyst was obtained in the same manner as in Example 1, except that in the molybdenum supporting step, the amount of silica sol added was 1,190 g, the amount of precipitate added was 682 g, the amount of powdered silica added was 801 g, and the amount of ammonium molybdate tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was 45.1 g. The catalyst obtained was subjected to the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0053] [Comparative Example 1: No molybdenum] A catalyst was obtained in the same manner as in Example 1, except that the molybdenum impregnation solution was not added in the molybdenum supporting step. The catalyst obtained was subjected to the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0054] [Comparative Example 2: High Nickel Content, High Molybdenum Content] A catalyst was obtained in the same manner as in Example 1, except that in the molybdenum supporting step, the amount of silica sol added was 540 g, the amount of precipitate added was 1,370 g, the amount of powdered silica added was 364 g, and the amount of ammonium molybdate tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was 180.7 g. The catalyst obtained was subjected to the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0055] [Comparative Example 3: No molybdenum impregnation solution used] A catalyst was obtained in the same manner as in Example 1, except that in the molybdenum supporting step, no molybdenum impregnation liquid was added, and 18.4 g of powdered molybdenum trioxide was added. The obtained catalyst was subjected to the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0056] [Comparative Example 4: High molybdenum content] A catalyst was obtained in the same manner as in Example 1, except that in the molybdenum supporting step, the amount of ammonium molybdate tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was 135.2 g. The catalyst obtained was subjected to the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0057] [Comparative Example 5: No sulfur] A catalyst was obtained in the same manner as in Example 1, except that 1,000 g of nickel nitrate hydrate (Ni(NO3)2·6H2O, Fujifilm Wako Pure Chemical Industries, Ltd.) was added instead of nickel sulfate hydrate (NiSO4·6H2O, Fujifilm Wako Pure Chemical Industries, Ltd.) in the mother liquor preparation step. The obtained catalyst was subjected to the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0058] [Comparative Example 6: Medium nickel content, no molybdenum] A catalyst was obtained in the same manner as in Example 4, except that in the molybdenum supporting step, the amount of ammonium molybdate added was 0 g. The obtained catalyst was subjected to the above-mentioned measurements and evaluations. The results are shown in Table 1.

[0059] [Table 1]

[0060] When the catalyst of Comparative Example 1, which does not contain molybdenum, is compared with the catalyst of Example 1, it is confirmed that the inclusion of molybdenum increases the NBA selectivity. It is also confirmed that the catalyst of Example 1 has a shorter reaction time and higher activity than the catalyst of Comparative Example 1. It is also confirmed that the catalyst of Example 4, which has a higher nickel content than the catalyst of Example 1, and the catalyst of Comparative Example 6, which has the same nickel content, show the same tendency. Comparing the sulfur-free catalyst of Comparative Example 5 with the catalyst of Example 1, it was confirmed that the inclusion of sulfur increases the NBA selectivity. In addition, it was confirmed that the catalyst of Example 1 had a shorter reaction time and higher activity than the catalyst of Comparative Example 5. Comparing the catalyst of Comparative Example 3, in which the standard deviation of molybdenum cations is 0.7 or more, with the catalyst of Example 1, it was confirmed that the NBA selectivity was increased by reducing this standard deviation. In addition, it was confirmed that the catalyst of Example 1 had a shorter reaction time and higher activity than the catalyst of Comparative Example 3. When comparing the catalyst of Comparative Example 4, which has a molybdenum content of more than 5 mass%, with the catalyst of Example 1, it was confirmed that by lowering the molybdenum content, the number and standard deviation of molybdenum cations were reduced and the NBA selectivity was increased.

[0061] This application claims priority to Japanese Patent Application No. 2023-52589, filed on March 29, 2023, the disclosure of which is incorporated herein in its entirety.

Claims

1. A catalyst for hydrogenating an aldehyde to synthesize an alcohol, comprising: Contains nickel, molybdenum, and sulfur, The nickel content is 5% by mass or more and 40% by mass or less in terms of NiO, The molybdenum content is MoO 3 In terms of mass conversion, it is 0.05 mass% or more and 5 mass% or less, The sulfur content is SO 3 In terms of mass conversion, it is 0.01 mass% or more and 1 mass% or less, The number of molybdenum cations is 2 or less, and The standard deviation of the number of cations is 0.7 or less. catalyst.

2. The catalyst described in claim 1, having a specific surface area of ​​50 m 2 / g or more and 250 m 2 / g or less.

3. The catalyst described in claim 1, wherein the crystallite diameter of the nickel is 10 nm or less.

4. The catalyst described in claim 1, comprising a support which is at least one or more selected from silica, alumina, silica alumina and diatomaceous earth.