Method for producing heterometal hydrogenation catalysts

Abstract

The present invention relates to a method for producing a heterogeneous metal hydrogenation catalyst, and more specifically, is characterized in that the hydrogenation reaction of the catalyst is improved when the hydrogenation catalyst is reduced under appropriate reduction conditions using a specific reducing gas.

Description

【Technical Field】 【0001】 The present invention relates to a method for manufacturing a heterogeneous metal hydrogenation catalyst. More specifically, when reducing the hydrogenation catalyst under appropriate reduction conditions using a specific reducing gas, the hydrogenation reaction of the catalyst is improved. 【Background Art】 【0002】 A heterogeneous hydrogenation catalyst can be manufactured in the order of supporting an active metal, reducing and passivating after drying. In order to have catalytic activity, catalytic activation in which the active metal component in the form of a supported metal compound is reduced to a metal must be involved. The activation of the catalyst can be carried out by reducing the active metal component before the reaction using a slurry reduction method and a thermal reduction method. 【0003】 Wet reduction has the advantage that it can reduce metals in a relatively short time at a relatively low temperature using reducing agents such as N2H4·H2O (hydrazine hydrate) and NaBH4 having a high hydrogen content. N2H4·H2O (hydrazine hydrate) as a reducing agent for the catalyst has a high reduction potential and a high reduction effect can be obtained even with a small amount, but it has the disadvantage that it can induce respiratory toxicity and environmental pollution problems. In Patent Document 1 (Beijing University of Chemical Technology), Ru-Pt-Sn / Al2O3 is presented as a dicarboxylic acid conversion catalyst, and a wet reduction method using NaBH4 was used for the reduction of the catalyst. NaBH4 having a high hydrogen content is hydrolyzed in an aqueous solution to generate hydrogen, and the metal compound is reduced through this. However, Na, B, etc. generated after the hydrolysis of NaBH4 act as catalyst poisons because they have a strong binding force with the metal and can reduce the activity of the catalyst. 【0004】 On the other hand, dry reduction is a method of reducing metal salts back into metals by supplying a reducing gas to a sample, mainly under heated conditions. Hydrogen, carbon dioxide, carbon monoxide, and methane are used as reducing agents, with hydrogen gas being the most commonly used. Hydrogen concentrated with air at specific mixing ratios carries the risk of deflagration or explosion. Therefore, for safe operation in commercial processes, it is common to use a mixture of hydrogen and an inactive gas with a composition of approximately 2% to 10% hydrogen as the base. 【0005】 In the case of dissimilar metal catalysts, the thermodynamic properties of the two metals differ, so appropriate reduction conditions are necessary when applying a dry reduction method. According to prior literature, the degree of reduction of dissimilar metals differs depending on the reduction temperature and the composition of the reducing gas, and when the two metals form an alloy, alloy phases with different ratios are formed depending on the reduction conditions, which affects the performance of the catalyst (Non-Patent Literature 1). 【0006】 Therefore, in order to solve the above-mentioned problems, the present inventors discovered that when a hydrogenation catalyst of a different metal is reduced using a specific reducing gas under appropriate reduction conditions, the hydrogenation catalyst can be used to efficiently convert dicarboxylic acid groups to dialcohol groups, thus completing the present invention. [Prior art documents] [Patent Documents] 【0007】 [Patent Document 1] Chinese Patent No. 102580732 Specification [Non-patent literature] 【0008】 [Non-Patent Document 1] Appl.Catal.A-Gen 315(2006)58-67 [Overview of the project] [Problems that the invention aims to solve] 【0009】 The present invention has been made to solve the problems of the prior art described above, and aims to provide a method for reducing heterogeneous metal hydrogenation catalysts. 【0010】 Furthermore, the objective is to provide a method for producing cyclohexanedimethanol (CHDM) using the activated heterometal hydrogenation catalyst. [Means for solving the problem] 【0011】 As a technical means for achieving the above-mentioned technical problems, one aspect of the present invention is: The present invention provides a method for reducing a heterometal hydrogenation catalyst, comprising the steps of: filling a reactor with a catalyst precursor on which heterometal compounds are supported; and simultaneously raising the temperature of the reactor and reducing the catalyst precursor while supplying a reducing gas. 【0012】 The aforementioned heterogeneous metal compound comprises a first metal and a second metal, wherein the first metal may comprise a compound of a metal selected from the group consisting of Ru, Pt, Pd, Rh, and combinations thereof, and the second metal may comprise a compound of a metal selected from the group consisting of Sn, Fe, Ga, Re, and combinations thereof. 【0013】 The molar ratio of the first metal and the second metal may be 1:0.5 to 3. 【0014】 The support may contain a substance selected from the group consisting of silica (SiO2), alumina (Al2O3), zirconia (ZrO2), titania (TiO2), carbon, and combinations thereof. 【0015】 The carbon may include a substance selected from the group consisting of activated carbon, carbon black, graphite, graphene, OMC (ordered mesoporous carbon), carbon nanotubes (CNT), and combinations thereof. 【0016】 The content of the different metal may be 1 part to 20 parts by weight based on 100 parts by weight of the carrier. 【0017】 The temperature increase may be carried out at a rate of 1 °C / min to 15 °C / min. 【0018】 The reduction may be carried out in a fixed bed type, fluidized bed type, moving bed type or static box type kiln, furnace or reactor. 【0019】 The reducing gas may include a gas selected from the group consisting of hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), ammonia (NH3), hydrogen sulfide (H2S), and combinations thereof. 【0020】 The supply amount of the reducing gas during the temperature increase may be not less than the number of moles of the metal compound contained per unit mass of the catalyst precursor. 【0021】 The reduction method of the different metal hydrogenation catalyst may further include a step of reducing the catalyst precursor while raising the temperature of the reactor; and a step of maintaining the temperature of the reactor thereafter. 【0022】 The temperature of the reactor to be maintained may be 200 °C to 500 °C. 【0023】 The temperature increase and maintenance of the reactor may be carried out over 30 minutes to 24 hours. 【0024】 The aforementioned dissimilar metal catalyst may be one used in hydrogenation reactions. 【0025】 The hydrogenation reaction may involve reducing a carboxylic acid functional group, an aldehyde functional group, or a ketone functional group to an alcohol functional group. 【0026】 The hydrogenation reaction described above may involve reducing a dicarboxylic acid functional group to a dialcohol functional group. 【0027】 Another aspect of the present invention is, The present invention provides a method for producing cyclohexanedimethanol (CHDM) by carrying out the hydrogenation reaction of cyclohexanedicarboxylic acid (CHDA) using the activated heterometal catalyst. 【0028】 The yield of the cyclohexanedimethanol (CHDM) produced may be 70% or more. [Effects of the Invention] 【0029】 According to the reduction method for heterometal hydrogenation catalysts of the present invention described above, it is possible to control the segregation, sintering, and leaching out of the active metal that may occur during the process of reducing heterometal compounds to metals, and a heterometal hydrogenation catalyst with an active metal supported in a uniform alloy status can be obtained. 【0030】 Furthermore, the catalyst reduced through the aforementioned reduction method for dissimilar metal catalysts may efficiently reduce dicarboxylic acid functional groups to dialcohol functional groups. [Brief explanation of the drawing] 【0031】 [Figure 1] This is a photograph showing the STEM-EDX analysis results of a heterogeneous metal catalyst according to an embodiment of the present invention. [Figure 2] This is a photograph showing the STEM-EDX analysis results of a heterogeneous metal catalyst according to a comparative example of the present invention. [Modes for carrying out the invention] 【0032】 The present invention will be described in further detail below. However, the present invention can be embodied in various different forms, and the present invention is not limited by the embodiments described herein; rather, the present invention is defined solely by the claims described later. 【0033】 Furthermore, the terminology used in this invention is used solely to describe specific embodiments and is not intended to limit the invention. A singular expression includes plural expressions unless the context clearly indicates otherwise. Throughout this specification, "including" a component means, unless otherwise stated, that it may include other components rather than excluding them. 【0034】 The first aspect of this application is, The present invention provides a method for reducing a heterometal hydrogenation catalyst, comprising the steps of: filling a reactor with a catalyst precursor in which heterometal compounds are supported on a carrier; and simultaneously raising the temperature of the reactor and supplying a reducing gas to reduce the heterometal compounds contained in the catalyst precursor to metal. 【0035】 Before providing a detailed explanation of the present invention, it should be noted that in bimetallic hydrogenation catalysts, the morphology, ratio, and dispersion of the active metals are closely correlated with the catalytic activity, depending on the purpose (Appl. Catal. A-Gen. 318 (2007) 70-78). Bimetallic hydrogenation catalysts are bifunctional catalysts in which the roles of the different active metals are distinct. They intentionally alloy metals with high oxygen affinity (e.g., Sn, Re, Ga, Fe, etc.) with noble metals to induce electronic ensemble effects, thereby effectively carrying out the hydrogenation reaction of carboxylic acid or carbonyl groups. Therefore, in order to obtain a catalyst with excellent catalytic activity, appropriate design of the active metals is necessary (Appl. Catal. A-Gen. 318 (2007) 70-78). 【0036】 On the other hand, for a supported catalyst precursor to have activity in the hydrogenation reaction, a reduction process is necessary in which a different metal compound is reduced to a metal. In the case of supported catalysts, a dry reduction method is usually used in which the temperature is raised while flowing a hydrogen-containing gas mixture to the desired reduction temperature. However, if insufficient reduction conditions are used during the heating process, the designed catalyst properties and performance cannot be obtained. If the temperature is raised too rapidly to the desired reduction temperature, or if the desired reduction temperature is excessively high, the metal particles may move or solidify on the surface during reduction, resulting in particle growth (sintering), which can reduce the effective reaction surface area of ​​the active metal participating in the reaction. Therefore, appropriate reduction conditions depending on the type of metal are essential (JA Anderson et al. "Supported Metals in Catalysis", Imperial College Press). 【0037】 Therefore, the present invention aims to solve the above-mentioned problems by reducing a heterometal hydrogenation catalyst under appropriate reduction conditions using a specific reducing gas. 【0038】 The reduction method of a heterometal hydrogenation catalyst relating to the first aspect of this application will be described in detail step by step below. 【0039】 First, in one embodiment of the present invention, the reduction method for the heterometal hydrogenation catalyst may include the step of filling a reactor with a catalyst precursor in which heterometal compounds are supported on a carrier. 【0040】 In one embodiment of the present application, the heterogeneous metal compound may include a first metal and a second metal. In this case, the first metal may include a compound of a metal selected from the group consisting of Ru, Pt, Pd, Rh and combinations thereof, and the second metal may include a compound of a metal selected from the group consisting of Sn, Fe, Ga, Re and combinations thereof. In this case, the molar ratio of the first metal and the second metal may be 1:0.5 to 3, preferably the same molar ratio, and more preferably they may be provided in the same molar ratio after reduction. In this case, if the molar ratio of the second metal to 1 mole of the first metal is less than 0.5 moles, the activation of the carboxylic acid functional group may be suppressed, making it difficult to obtain the selectivity of the desired product. On the other hand, if it exceeds 3 moles, the generation of metal-hydrides that participate in the hydrogenation reaction may be suppressed, and the catalyst may not be suitable for use in hydrogenation reaction applications. 【0041】 In one embodiment of the present invention, the first and second metals are active metals, and their metal crystallite size may be 1 nm to 20 nm, preferably 1 nm to 15 nm. In this case, if the crystallite size exceeds 20 nm, a high conversion rate is unlikely to be expected. 【0042】 In one embodiment of the present application, the support may contain a substance selected from the group consisting of silica (SiO2), alumina (Al2O3), zirconia (ZrO2), titania (TiO2), carbon, and combinations thereof, and preferably contains carbon. On the other hand, the carbon may contain a substance selected from the group consisting of activated carbon, carbon black, graphite, graphene, OMC (ordered mesoporous carbon), carbon nanotubes (CNTs), and combinations thereof. 【0043】 In one embodiment of the present invention, the carbon in the carbon support may have a volume ratio of 50% or more of mesopores, where the pore size is between 2 nm and 50 nm, within the total pores. Preferably, the carbon in the carbon support may have a volume ratio of 70% or more of mesopores within the total pores, and more preferably, the carbon in the carbon support may have a volume ratio of 75% or more of mesopores within the total pores. In this case, if the volume ratio of mesopores is less than 50%, there may be problems with the microscopic mass transfer rate of reactants and products within the carbon support, while if the average size of the pores exceeds 50 nm, there may be problems with the physical strength of the support being weakened, so the above range may be appropriate. 【0044】 In one embodiment of the present invention, the carbon has a specific surface area (BET) of 100 m². 2 / g~1,500m 2 It may also contain activated carbon in the range of / g. Preferably, the carbon has a specific surface area (BET) of 200m 2 / g~1,000m 2 It may also contain activated carbon in the range of / g. In this case, the specific surface area of ​​the carbon is 100m². 2 If the amount is less than / g, there may be a problem in that high dispersion of the active metal is difficult, whereas the specific surface area of ​​the carbon is 1,500 m². 2 If the value exceeds / g, there is a possibility of a problem with a low mesostomatal ratio, so the above range may be appropriate. 【0045】 In one embodiment of the present invention, the carbon support may contain micropores in an appropriate ratio in addition to being of intermediate size mesoporous properties, preferably with a volume ratio of 0% to 25% of the total pores. In this case, if the volume ratio of micropores exceeds 25%, there may be problems with the microscopic mass transfer rate of reactants and products within the carbon support, so the above range may be appropriate. 【0046】 In one embodiment of the present application, the content of the different metals may be 1 to 20 parts by weight per 100 parts by weight of the carrier. Specifically, the content of the first metal may be 1 to 10 parts by weight per 100 parts by weight of the carrier, preferably 3 to 7 parts by weight. If the content of the different metals is less than 1 part by weight per 100 parts by weight of the carrier, the conversion efficiency of the reaction may decrease, the selectivity of the target product may decrease, and excessive separation and recovery costs may be incurred during the process. On the other hand, if it exceeds 20 parts by weight, problems may arise inefficiency due to the generation of a large amount of by-products. 【0047】 In one embodiment of the present invention, the hydrogenation catalyst has an average particle size (d 50 The particle size may be between 3 μm and 50 μm. If the catalyst particle size is smaller than the above range, catalyst loss may occur as the catalyst passes through the filtration membrane, potentially leading to problems with product purity and cost due to catalyst loss. On the other hand, if it exceeds the above range, the degree of dispersion in the reaction medium will be low, potentially leading to problems such as a decrease in the efficiency of the hydrogenation reaction. 【0048】 In one embodiment of the present invention, the active metal of the hydrogenation catalyst may form a homogeneous mixed phase. In this case, if the heterogeneous active metals are, for example, ruthenium (Ru) and tin (Sn), the Ru and Sn may not exist independently but form a homogeneous mixed phase. 【0049】 In this regard, there is a literature report that in heterometal hydrogenation catalysts, the uniformity of the metal composition correlates with catalytic activity (J.Mol.Catal A Chem 2015, 410, 184). Therefore, in order to obtain excellent catalytic activity with the same amount of metal loading, high uniformity between the two metals is essential. On a heterometal hydrogenation catalyst, the first metal plays a role in generating a metal-hydrogen compound while adsorbing hydrogen, and the second metal acts as a Lewis acid site, polarizing the carbonyl group. Subsequently, the metal-hydrogen compound is adsorbed onto the activated carbonyl group and converted to an alcohol, so uniformity of the heterometal active phase is absolutely required for efficient reduction of the carbonyl group. Therefore, the catalyst according to the present invention may provide a heterometal active phase with a uniform composition and improve the efficiency of the reaction. 【0050】 Next, in one embodiment of the present invention, the method for reducing the hydrogenation catalyst may include the step of supplying a reducing gas at the same time as raising the temperature of the reactor to reduce the heterogeneous metal compounds contained in the catalyst to a metal. 【0051】 In one embodiment of the present application, the reducing gas may include a gas selected from the group consisting of hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), ammonia (NH3), hydrogen sulfide (H2S), and combinations thereof, and preferably includes hydrogen (H2) which has a high reducing potential. 【0052】 In one embodiment of the present invention, the heating may be carried out at a rate of 1°C / min to 15°C / min, and preferably at a rate of 1°C / min to 5°C / min. If the heating rate is less than 1°C / min, the heat treatment time to reach the target temperature is long, which is inefficient. On the other hand, if it exceeds 15°C / min, a problem may arise in which the sintering phenomenon of the metal is accelerated due to the rapid supply of heat under insufficient reduction conditions. 【0053】 In one embodiment of the present invention, the reduction must be carried out in a fixed-bed, fluidized-bed, moving-bed, or static-box type kiln, furnace, or reactor, as it must be possible to easily inflow and outflow the reducing gas and to supply the reducing gas simultaneously with the heating. 【0054】 In one embodiment of the present invention, the amount of reducing gas supplied during the heating process may be equal to or greater than the number of moles of the metal compound contained per unit mass of the heterometal hydrogenation catalyst. If the amount of reducing gas supplied is less than the number of moles of the metal compound contained per unit mass of the heterometal hydrogenation catalyst, or if no reducing gas is supplied, the heterometal alloy may not be formed during the heat treatment process during heating, resulting in segregation, or metal leaching may occur, and the catalyst of the desired design may not be obtained. Furthermore, insufficient reduction conditions may not effectively remove ligands of the metal compound, thus reducing reaction efficiency and potentially causing side reactions. 【0055】 Next, in one embodiment of the present invention, the method for reducing the hydrogenation catalyst may further include the steps of reducing the dissimilar metal compound while raising the temperature of the reactor, and maintaining the temperature of the reactor thereafter. 【0056】 In one embodiment of the present invention, the maintained reactor temperature may be 200°C to 500°C, preferably 350°C to 450°C. In this case, the step of maintaining the reactor temperature after the heating may be performed to complete the reduction of the heterometal hydrogenation catalyst. On the other hand, if the reduction temperature is below 200°C, the ligands of the heterometal compounds may not be sufficiently removed, and the metal may not be completely reduced, which may lead to side reactions. On the other hand, if it exceeds 500°C, the problem of accelerating the sintering phenomenon of the metal may occur. 【0057】 In one embodiment of the present invention, the heating and maintenance of the reactor may be carried out over a period of 30 minutes to 24 hours. In this case, if the heating and maintenance of the reactor, i.e., the heat treatment time, is less than 30 minutes, the reduction of the dissimilar metal hydrogenation catalyst will not occur smoothly, while if it exceeds 24 hours, an improved reduction effect cannot be obtained, which is economically disadvantageous. 【0058】 In one embodiment of the present invention, the heterometal hydrogenation catalyst may be used in a hydrogenation reaction. In this case, the hydrogenation reaction may reduce a carboxylic acid functional group, an aldehyde functional group, or a ketone functional group to an alcohol functional group, preferably a dicarboxylic acid functional group to a dialcohol functional group, and more preferably a cyclohexane dicarboxylic acid (CHDA) to cyclohexane dimethanol (CHDM). 【0059】 In one embodiment of the present application, the carboxylic acids having a carboxylic acid functional group may include, for example, substances selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isopthalic acid, terephthalic acid, formic acid, acetic acid, caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, maleic acid, adipic acid, sebacic acid, cyclohexanecarboxylic acid, benzoic acid, and combinations thereof. 【0060】 In one embodiment of the present application, the aldehydes having an aldehyde functional group may include, for example, substances selected from the group consisting of formaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, 2-methylbutyraldehyde, 3-methylbutyraldehyde, 2,2-dimethylpropionaldehyde, caproaldehyde, 2-methylvaleraldehyde, 3-methylvaleraldehyde, 4-methylvaleraldehyde, 2-ethylbutyraldehyde, 2,2-dimethylbutyraldehyde, 3,3-dimethylbutyraldehyde, caprylaldehyde, caprinaldehyde, glutardialdehyde, and combinations thereof. 【0061】 In one embodiment of the present application, the ketones having a ketone functional group may include, for example, substances selected from the group consisting of acetone, butanone, pentanone, hexanone, cyclohexanone, acetophenone, and combinations thereof. 【0062】 The second aspect of this application is, The present invention provides a method for producing cyclohexanedimethanol (CHDM) by carrying out the hydrogenation reaction of cyclohexane dicarboxylic acid (CHDA) using a reduced heterometal hydrogenation catalyst according to the first aspect of the present invention. 【0063】 Although detailed explanations of the parts that overlap with the first aspect of this application have been omitted, the content explained for the first aspect of this application can be applied in the same way to the second aspect, even if the explanation is omitted. 【0064】 The following describes in detail a method for producing cyclohexanedimethanol (CHDM) according to the second aspect of this application. 【0065】 In one embodiment of the present invention, the hydrogenation reaction may be carried out at a temperature of 200°C to 300°C for 2 to 24 hours, and the pressure may be in the range of 50 bar to 150 bar. Preferably, the hydrogenation reaction temperature of CHDA may be in the range of 200°C to 270°C, and the pressure may be in the range of 70 bar to 130 bar. In this case, if the temperature is less than 180°C, the reaction rate is insufficient, and the yield may be lower than the target CHDM yield, while if it exceeds 300°C, side reactions such as decomposition of reactants and products may occur. On the other hand, if the pressure is less than 50 bar, there may be a problem in that the reaction rate decreases because there is not enough hydrogen in the solvent to participate in the reaction during the hydrogenation reaction of CHDA, while if the hydrogenation reaction pressure exceeds 150 bar, no further improvement in the reaction rate can be obtained, which may be economically disadvantageous. Most preferably, the hydrogenation reaction temperature is 200°C to 250°C, the reaction pressure is in the range of 80 bar to 110 bar, and the reaction time is 2 hours to 6 hours. 【0066】 In one embodiment of the present application, the yield of the cyclohexanedimethanol (CHDM) produced may be 70% or more, preferably 85% or more, and most preferably 95% or more. 【0067】 Hereinafter, embodiments of the present invention will be described in detail so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. However, the present invention can be embodied in a variety of different forms and is not limited to the embodiments described herein. 【0068】 Manufacturing example: Production of catalyst precursors 【0069】 The catalyst precursor was prepared by supporting Ru and Sn metals on a carbon support using the incipient-wetness impregnation method. After quantitatively dissolving a ruthenium compound (RuCl3·3H2O) and a tin compound (SnCl2·2H2O) in ultrapure water, the solutions were simultaneously dropped onto the carbon support in a drop-wise manner and co-impregnated by stirring with a mortar and pestle. Of the dissimilar active metals, Ru was supported at a rate of 5 parts by weight per 100 parts by weight of the carbon support, and Sn was supported at the same molar amount as Ru. Subsequently, the supported samples were dried in a drying oven at 100°C for 12 hours to produce catalyst precursors in which the dissimilar metals Ru and Sn were supported on carbon. 【0070】 Example 1. Reduction of catalyst precursor (using 5% H2) 【0071】 The catalyst precursor produced in the above manufacturing example was reduced in a fixed-bed reactor. The reduction equipment consisted of a reactor to which the catalyst was installed, a reactor heater to adjust the sample temperature, and a Mass Flow Controller (MFC) to adjust the gas flow rate. The catalyst reduction was carried out by using a PID controller to programmatically raise the sample temperature to the target reduction temperature, while simultaneously flowing a reducing gas to the reduction temperature for heat treatment. At this time, 5% hydrogen gas (N2 balance) was used as the reducing gas, and the temperature was raised to the reduction temperature of 350°C at a rate of 5°C / min and maintained for 3 hours. The flow rate (F / W: H2-ml / min.g-Cat.) of hydrogen per unit mass of catalyst precursor introduced during the heating stage of the reduction process was adjusted, and the total amount of hydrogen introduced is shown in Table 1 below. The catalyst, after reduction was complete, was cooled to room temperature while flowing nitrogen (F / W: 20 ml-N2 / min.g-Cat.), and the catalyst was passivated while flowing a 3% oxygen / nitrogen mixed gas (F / W: 20 ml / min.g-Cat.) at room temperature for 2 hours. 【0072】 Example 2. Reduction of catalyst precursor (using 100% H2) 【0073】 The catalyst precursor was reduced using the same method as in Example 1, except that 100% pure hydrogen gas was used as the reducing gas instead of 5% hydrogen gas. 【0074】 Example 3. Reduction of catalyst precursor (100% H2 used only during the heating stage) 【0075】 In Example 1, the catalyst precursor was reduced using the same method, except that 100% pure hydrogen gas was used as the reducing gas instead of 5% hydrogen gas, and it was supplied only during the heating stage. 【0076】 Specifically, the catalyst precursor produced in the above production example was heated to 350°C at a rate of 5°C / min and reduced for 3 hours. During this time, pure hydrogen was supplied only during the heating phase (approximately 70 minutes) of the reduction process, and replaced with nitrogen gas during the maintenance phase. After the reduction was complete, the catalyst was cooled to room temperature while flowing nitrogen (F / W: 20 ml-N2 / min.g-Cat.), and the catalyst was passivated at room temperature while flowing a 3% oxygen / nitrogen mixed gas (F / W: 20 ml / min.g-Cat.) for 2 hours. 【0077】 Comparative Example 1. Reduction of catalyst precursor (using 100% N2) 【0078】 The catalyst precursor was reduced using the same method as in Example 1, except that 100% pure nitrogen (N2) gas was used as the reducing gas instead of 5% hydrogen gas. 【0079】 Comparative Example 2. Reduction of Catalyst Precursor (using 100% N2 / 100% H2) 【0080】 The catalyst precursor produced in the above production example was heated to 350°C at a rate of 5°C / min and reduced for 3 hours. During this time, nitrogen was supplied during the heating phase of the reduction process, and after reaching 350°C, the gas was replaced with hydrogen and supplied for 180 minutes. The catalyst, after reduction was complete, was cooled to room temperature while flowing nitrogen (F / W = 0.05 g - Cat.min / ml), and the catalyst was passivated at room temperature while flowing a 3% oxygen / nitrogen mixed gas (flow rate: F / W = 0.05 g - Cat.min / ml) for 2 hours. 【0081】 Experimental example: Hydrogenation reaction of cyclohexane dicarboxylic acid (CHDA) 【0082】 Experiments were conducted to produce cyclohexanedimethanol (CHDM) through the hydrogenation reaction of cyclohexanedicarboxlyic acid (CHDA), a representative dicarboxylic acid. This reaction was carried out in a batch reactor made of acid-resistant titanium-lined stainless steel with a maximum operating pressure of 100 bar. CHDA and the heterometal hydrogenation catalysts reduced in the above examples and comparative examples were injected into the reactor in a weight ratio of 3.75:1, and distilled water was packed as the reaction solvent. At this time, the amount of reactants relative to the solvent was fixed at 1.6 wt%. Subsequently, hydrogen was pressurized to the reaction pressure of 90 bar, and after checking for leaks in the reactor using a hydrogen sensor, the pressure was reduced and the reactor was purged to remove all oxygen from inside the reactor. The hydrogenation reaction was carried out by heating the reactor to the reaction temperature (230°C), then pressurizing and maintaining a hydrogen atmosphere at a reaction pressure (90 bar), and stirring the reaction mixture at 1000 rpm for 6 hours using an overhead stirrer. The product was sampled at different reaction times through a metal filter, silylated with BSTFA (N,O-Bis(trimethylsilyl)trifluoroacetamide), and then analyzed for the product and residual reaction products using gas chromatography (DS-SCIENCE) equipped with an HP-1 column (Agilent). The results are shown in Figures 1 and 2 and Table 1 below. 【0083】 [Table 1] 【0084】 a)F / W:volumetric flow rate per catalyst precursor weight(ml / min.g-Cat.) 【0085】 We were able to clearly observe differences in the degree of metal dispersion, crystal size, and the composition of the active metal depending on the type of reducing gas introduced during the heating process. 【0086】 Specifically, Figure 1 shows the results of STEM-EDX (Energy Dispersive X-Ray spectroscopy) mapping analysis of each catalyst (Examples 1 to 3) after hydrogen was flowed through them during heating. Observed by electron imaging, each metal showed a uniform distribution of its active components on the carbon support, with a size of 5 nm or less. Table 1 shows the Sn / Ru atomic ratio of the active sites analyzed from the EDX mapping results. It was confirmed that the Sn / Ru composition was almost identical to that of the introduced metal, confirming that the catalyst was manufactured as originally planned. 【0087】 Figure 2 shows the results of STEM-EDX (Energy Dispersive X-Ray spectroscopy) mapping analysis of each catalyst (Comparative Examples 1 and 2) after nitrogen was flowed during heating. Observation from the electron images revealed that each metal formed partial agglomerates of 10 nm or more, which were predominantly Ru-dominant, confirming that phase segregation occurred during reduction. Analysis of the Sn / Ru ratio from the EDX mapping results also showed a low Sn ratio, indicating that the catalyst was not manufactured as designed. 【0088】 Finally, Table 1 shows the amount of hydrogen input and catalytic activity under catalytic reduction conditions, expressed as CHDM yield. Each catalyst with hydrogen input during reduction showed a high CHDM yield of over 70%, while each catalyst with nitrogen input during heating showed a low CHDM yield. The activity of heterogeneous metal catalysts is proportional to the appropriate Sn / Ru ratio of the active metals and the amount of hydrogen that can participate in the reaction. However, in catalysts where nitrogen was used during heating, the heat source was supplied under insufficient reduction conditions, resulting in segregation of the active site or elution of Sn metal. The reducing gas supplied during heating significantly affects the effective reaction surface area of ​​the active metal, including the size and dispersion of the active metal particles, and it was confirmed that this plays a crucial role in determining the catalyst's activity in the CHDA conversion reaction. 【0089】 Although the present invention has been described in detail above with reference to the drawings and preferred embodiments, the scope of the technical idea of ​​the present invention is not limited by these drawings and embodiments. Therefore, various modifications or equivalent embodiments may exist within the scope of the technical idea of ​​the present invention. Accordingly, the scope of rights of the technical idea according to the present invention must be interpreted by the claims, and technical ideas within an equivalent or comparable scope should be interpreted as belonging to the scope of rights of the present invention. 【0090】 (Note) (Note 1) The step of filling a reactor with catalyst precursors on which different metal compounds are supported; and A step in which the reactor is heated, and at the same time a reducing gas is supplied to reduce the different metal compounds contained in the catalyst precursor; A method for reducing heterogeneous metal hydrogenation catalysts containing the following: 【0091】 (Note 2) The aforementioned heterogeneous metal compound includes a first metal and a second metal. The first metal comprises a compound of a metal selected from the group consisting of Ru, Pt, Pd, Rh, and combinations thereof. The second metal includes a compound of a metal selected from the group consisting of Sn, Fe, Ga, Re, and combinations thereof. A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 1. 【0092】 (Note 3) The molar ratio of the first metal and the second metal is 1:0.5 to 3. A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 2. 【0093】 (Note 4) The aforementioned support comprises a substance selected from the group consisting of silica (SiO2), alumina (Al2O3), zirconia (ZrO2), titania (TiO2), carbon, and combinations thereof. A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 1. 【0094】 (Note 5) The carbon in question includes substances selected from the group consisting of activated carbon, carbon black, graphite, graphene, OMC (Ordered Mesoporous Carbon), carbon nanotubes (CNTs), and combinations thereof. A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 4. 【0095】 (Note 6) The content of the aforementioned different metal compounds is 1 to 20 parts by weight per 100 parts by weight of the carrier. A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 1. 【0096】 (Note 7) The aforementioned heating is carried out at a rate of 1°C / min to 15°C / min. A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 1. 【0097】 (Note 8) The reduction is carried out in a fixed-bed, fluidized-bed, moving-bed, or static-box type kiln, furnace, or reactor. A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 1. 【0098】 (Note 9) The reducing gas includes gases selected from the group consisting of hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), ammonia (NH3), hydrogen sulfide (H2S), and combinations thereof. A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 1. 【0099】 (Note 10) The amount of reducing gas supplied during the heating process is equal to or greater than the number of moles of metal compound contained per unit mass of the catalyst precursor. A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 1. 【0100】 (Note 11) The reduction method for the aforementioned heterometal hydrogenation catalyst is: A step of reducing the dissimilar metal compounds while raising the temperature of the reactor; and The further step includes maintaining the temperature of the reactor thereafter; A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 1. 【0101】 (Note 12) The temperature of the reactor to be maintained is between 200°C and 500°C. A method for reducing a heterometal hydrogenation catalyst as described in Appendix 11. 【0102】 (Note 13) The heating and maintenance of the reactor is carried out over a period of 30 minutes to 24 hours. A method for reducing a heterometal hydrogenation catalyst as described in Appendix 11. 【0103】 (Note 14) The catalyst is used in the hydrogenation reaction. A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 1. 【0104】 (Note 15) The hydrogenation reaction described above reduces a carboxylic acid functional group, an aldehyde functional group, or a ketone functional group to an alcohol functional group. A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 14. 【0105】 (Note 16) The aforementioned hydrogenation reaction reduces the dicarboxylic acid functional group to a dialcohol functional group. A method for reducing heterogeneous metal hydrogenation catalysts as described in Appendix 14. 【0106】 (Note 17) A method for producing cyclohexanedimethanol (CHDM) by hydrogenating cyclohexanedicarboxylic acid (CHDA) using an activated heterometal hydrogenation catalyst as described in Appendix 1. 【0107】 (Note 18) The yield of the cyclohexanedimethanol (CHDM) produced is 70% or more. A method for producing cyclohexanedimethanol (CHDM) as described in Appendix 17. [Industrial applicability] 【0108】 According to the method for reducing heterometal hydrogenation catalysts according to the present invention described above, it is possible to control the segregation, sintering, and leaching of active metals that may occur during the process of reducing heterometal compounds to metals, and a heterometal hydrogenation catalyst on which active metals in a uniform alloy state are supported can be obtained. 【0109】 Furthermore, the catalyst reduced through the aforementioned reduction method for dissimilar metal catalysts may efficiently reduce dicarboxylic acid functional groups to dialcohol functional groups.

Claims

[Claim 1] The step of filling a reactor with catalyst precursors on which different metal compounds are supported; and A step in which the reactor is heated, and at the same time a reducing gas is supplied to reduce the different metal compounds contained in the catalyst precursor; The heating is carried out at a rate of 1°C / min to 5°C / min, The reducing gas is hydrogen (H ２ ) or hydrogen (H ２ ) and nitrogen (N ２ ) contains a mixed gas, The aforementioned heterogeneous metal compound includes a first metal and a second metal. The first metal contains a Ru compound, The second metal contains a compound of Sn. A method for producing a heterometal hydrogenation catalyst. [Claim 2] The molar ratio of the first metal and the second metal is 1:0.5 to 3. A method for producing a heterometal hydrogenation catalyst as described in claim 1. [Claim 3] The aforementioned carrier is silica (SiO ２ ), alumina (Al ２ O ３ ), Zirconia (ZrO ２ ), Titania (TiO ２ ), containing a substance selected from the group consisting of carbon and combinations thereof, A method for producing a heterometal hydrogenation catalyst as described in claim 1. [Claim 4] The carbon in question includes substances selected from the group consisting of activated carbon, carbon black, graphite, graphene, OMC (Ordered Mesoporous Carbon), carbon nanotubes (CNTs), and combinations thereof. A method for producing a heterometal hydrogenation catalyst according to claim 3. [Claim 5] The content of the aforementioned different metal compounds is 1 to 20 parts by weight per 100 parts by weight of the carrier. A method for producing a heterometal hydrogenation catalyst as described in claim 1. [Claim 6] The reduction is carried out in a fixed-bed, fluidized-bed, moving-bed, or static-box type kiln, furnace, or reactor. A method for producing a heterometal hydrogenation catalyst as described in claim 1. [Claim 7] The amount of reducing gas supplied during the heating process is equal to or greater than the number of moles of the metal compound contained per unit mass of the catalyst precursor. A method for producing a heterometal hydrogenation catalyst as described in claim 1. [Claim 8] The method for producing the aforementioned heterometal hydrogenation catalyst is as follows: A step of reducing the dissimilar metal compounds while raising the temperature of the reactor; and The process further includes the step of maintaining the temperature of the reactor thereafter; A method for producing a heterometal hydrogenation catalyst as described in claim 1. [Claim 9] The temperature of the reactor to be maintained is between 200°C and 500°C. A method for producing a heterometal hydrogenation catalyst according to claim 8. [Claim 10] The heating and maintenance of the reactor is carried out over a period of 30 minutes to 24 hours. A method for producing a heterometal hydrogenation catalyst according to claim 8. [Claim 11] The catalyst is used in the hydrogenation reaction. A method for producing a heterometal hydrogenation catalyst as described in claim 1. [Claim 12] The hydrogenation reaction described above reduces a carboxylic acid functional group, an aldehyde functional group, or a ketone functional group to an alcohol functional group. A method for producing a heterometal hydrogenation catalyst according to claim 11. [Claim 13] The aforementioned hydrogenation reaction reduces the dicarboxylic acid functional group to a dialcohol functional group. A method for producing a heterometal hydrogenation catalyst according to claim 11. [Claim 14] A method for producing cyclohexanedimethanol (CHDM) by performing a hydrogenation reaction of cyclohexanedicarboxylic acid (CHDA) using a heterometal hydrogenation catalyst produced by the manufacturing method described in claim 1. [Claim 15] The yield of the cyclohexanedimethanol (CHDM) produced is 70% or more. A method for producing cyclohexanedimethanol (CHDM) according to claim 14.

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