Hydrogenation catalyst

Abstract

The present invention provides a hydrogenation reaction catalyst, and more particularly, to a hydrogenation catalyst capable of achieving high selectivity and high conversion rate in a hydrogenation reaction for converting a carboxylic acid group, an aldehyde group or a ketone group into an alcohol group.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0187904 filed on December 28, 2022, and all contents disclosed in the above Korean patent application document constitute a part of this specification.

[0003] The present invention relates to a hydrogenation catalyst, and more particularly, to a hydrogenation catalyst having high selectivity and high conversion rate in a hydrogenation reaction of converting a carboxylic acid group, an aldehyde group or a ketone group into an alcohol group. Background Art

[0004] Generally, compounds containing an alcohol group correspond to organic compounds having a hydroxyl group, and many alcohol compounds are very important compounds widely used in various industrial fields.

[0005] Examples of alcohols containing one hydroxyl group (monohydric alcohols) include methanol, ethanol, and n-propanol. Many monohydric alcohols are commonly used as raw materials for chemical synthesis or as solvents. Furthermore, examples of alcohols containing two hydroxyl groups (dihydric alcohols or glycols) include ethylene glycol, propylene glycol, and 1,4-butanediol. These glycol compounds are widely used as basic industrial raw materials for various products, including polyesters, polyurethanes, varnishes, adhesives, and pharmaceuticals.

[0006] Many of these important alcohol compounds have already been industrialized and mass-produced. Specifically, the olefin hydration method is known as a method for industrially producing primary alcohols (alcohols containing a hydroxymethyl group, -CH2OH), primarily used in the production of ethanol. Furthermore, for the production of alcohols other than ethanol with three or more carbon atoms (such as n-propanol, n-butanol, or 1,4-butanediol), methods are known that involve hydrogenating carboxylic acid esters in the presence of a copper-containing catalyst under high temperature and high pressure conditions. However, in existing hydrogenation reactions, after the esterified compound is generated from the carboxylic acid, the resulting esterified compound must then be hydrogenated, which inevitably complicates the production process for the primary alcohol.

[0007] In addition, in recent years, the demand for environmentally friendly and biodegradable diol compounds has grown significantly. These diol compounds can be converted from dicarboxylic acids or their derivatives using hydrogenation catalysts. Currently, the existing catalytic processes to achieve this goal are mostly based on Cu-Cr or Zr-Cr catalytic processes, or catalytic processes based on ruthenium oxide, ruthenium-carbon composites, etc., but these catalytic processes require high pressure (200-300 bar) operating conditions.

[0008] Mitsubishi Chemical Corporation (MCC) and Asahi Kasei Corporation have obtained patents for RuPtSn / C catalysts for converting dicarboxylic acids to diols (US6294703 and US6495730). However, Pt suffers from greater price volatility and higher costs compared to Ru. Lotte Chemical has also filed a patent (WO 2015-156582) for supporting the same metal (RuPtSn) on Y-type zeolite. However, this technology also results in high catalyst costs and requires an additional layering process for hydrothermal reactions, which is inconvenient.

[0009] Therefore, there is a need to develop a catalyst that can efficiently carry out the hydrogenation reaction of carboxylic acids or carboxylic esters under relatively low pressure conditions without requiring excessively long reaction times or high temperature conditions, even without using expensive precious metals such as platinum (Pt).

[0010] [Prior art literature]

[0011] [Patent Document]

[0012] Japanese Patent Publication No. 1995-165644

[0013] China Patent Publication No. 001911504

[0014] U.S. Patent Publication No. 6,294,703

[0015] U.S. Patent Publication No. 6,495,730

[0016] International Patent Publication No. WO 2015-156582 Summary of the Invention

[0017] [Technical Issues]

[0018] The present invention provides a hydrogenation catalyst that can achieve high selectivity and high conversion rate in the hydrogenation reaction of converting carboxylic acid groups, aldehyde groups or ketone groups into alcohol groups under relatively low pressure conditions without requiring excessively long reaction times or high temperature conditions.

[0019] The present invention also provides a method for preparing the hydrogenation catalyst.

[0020] [Technical solution]

[0021] According to one embodiment of the present invention, there is provided a hydrogenation catalyst comprising ruthenium and tin as catalytically active metals,

[0022] wherein, based on the total weight of ruthenium and tin, the content of ruthenium is greater than 30 weight % and less than 55 weight %, and the content of tin is greater than 45 weight % and less than 70 weight %;

[0023] The hydrogen adsorption ratio (A2 / A1) of the hydrogenation catalyst is 70 mol% to 99 mol%, and the hydrogen adsorption ratio (A2 / A1) is measured by hydrogen temperature-programmed reduction (H2-TPR) analysis, which is the ratio of the hydrogen adsorption amount (A2) of the hydrogenation catalyst at a temperature below 523K to the total hydrogen adsorption amount (A1) of the hydrogenation catalyst.

[0024] According to another embodiment of the present invention, a method for preparing the hydrogenation catalyst is provided.

[0025] According to yet another embodiment of the present invention, a hydrogenation method is provided for carrying out a hydrogenation reaction using the above catalyst.

[0026] [Beneficial Effects]

[0027] According to the present invention, the hydrogenation catalyst shows the excellent effect of achieving high selectivity and high conversion rate in the hydrogenation reaction of converting carboxylic acid groups, aldehyde groups or ketone groups into alcohol groups under relatively low pressure conditions without excessively long reaction time or high temperature conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Shown are hydrogen adsorption curves of the passivation layers of Examples 1 to 2 and Comparative Examples 1 to 3 according to embodiments of the present disclosure, which are based on hydrogen temperature-programmed reduction (H2-TPR) analysis. DETAILED DESCRIPTION

[0029] The terms used in this specification are only used to explain exemplary embodiments and are not intended to limit the present invention. Unless the context indicates otherwise, a singular expression may include a plural expression.

[0030] In this specification, terms such as "comprising", "having" or "including" are used to describe the implemented features, quantities, steps, components or their combinations, and do not exclude the possibility of one or more other features, quantities, steps, components, their combinations or additional items.

[0031] In addition, the terms of degree such as "approximately" and "substantially" used in this specification, when expressing inherent manufacturing and material tolerances, have a meaning equal to or close to a numerical value and are used to prevent unlawful infringers from improperly exploiting the disclosed content. The accurate or absolute numerical values mentioned therein are helpful for understanding this application.

[0032] For reference, "parts by weight" herein refers to a relative concept of the ratio of the weight of the remaining materials based on the weight of a specific material. For example, in a mixture containing 50 g of material A, 20 g of material B, and 30 g of material C, based on 100 parts by weight of material A, the amounts of material B and material C are 40 parts by weight and 60 parts by weight, respectively.

[0033] At the same time, "wt% (percentage by weight)" refers to an absolute concept expressing the weight of a specific material as a percentage of the total weight. In the above example mixture, based on the total weight of the mixture being 100%, the contents of Material A, Material B, and Material C are 50 wt%, 20 wt%, and 30 wt%, respectively. In this case, the total content of each component does not exceed 100 wt%.

[0034] The present invention can be modified in various ways and has various forms, and specific embodiments will be described in detail below. However, it should be understood that this description is not intended to limit the invention to the specific forms disclosed, but rather is intended to cover all modifications, equivalents, and alternatives that are consistent with the spirit and scope of the invention.

[0035] Hereinafter, the hydrogenation catalyst of the present invention, the preparation method thereof, and the hydrogenation method using the catalyst will be described in more detail.

[0036] Hydrogenation catalyst

[0037] According to one embodiment of the present invention, a hydrogenation catalyst is provided that can achieve high selectivity and high conversion rate in the hydrogenation reaction of converting carboxylic acid groups, aldehyde groups or ketone groups into alcohol groups under relatively low pressure conditions without excessive reaction time or high temperature conditions.

[0038] The hydrogenation catalyst according to one embodiment of the present invention contains ruthenium and tin as catalytically active metals.

[0039] Specifically, the hydrogenation catalyst is characterized in that the content of ruthenium is greater than 30% by weight and less than 55% by weight, based on the total weight of ruthenium and tin, and the content of tin is greater than 45% by weight and less than 70% by weight, based on the total weight of ruthenium and tin. In addition, the hydrogenation catalyst has a hydrogen adsorption ratio (A2 / A1) of 70 mol% to 99 mol%, and the hydrogen adsorption ratio (A2 / A1) is measured by hydrogen temperature programmed reduction (H2-TPR) analysis, which is the ratio of the hydrogen adsorption amount (A2) of the hydrogenation catalyst at a temperature below 523K (Kelvin temperature) to the total hydrogen adsorption amount (A1) of the hydrogenation catalyst.

[0040] Specifically, the hydrogenation catalyst according to one embodiment of the present disclosure is a catalyst that is intended to form a homogeneous alloy state of catalytically active metals ruthenium and tin, and the content is controlled within a specific range. Generally, platinum (Pt) among precious metals is used as a hydrogenation catalyst because it has a high hydrogen adsorption capacity, promotes the reduction of tin (Sn) species, and improves catalyst performance and stability by preventing the leaching of tin (Sn) that occurs in the hydrothermal reaction. However, the above-mentioned hydrogenation catalyst can show a better hydrogenation reaction effect without the use of expensive platinum (Pt), and has the characteristic that tin (Sn) leaching does not occur during the reaction process.

[0041] Specifically, the reduction mechanism of carboxylic acid groups on the composite metal (Ru-Sn) phase in the hydrogenation catalyst is as follows: Ruthenium (Ru) metal absorbs hydrogen to form a metal-hydrogen compound (metal hydride), while tin (Sn) acts as a Lewis acid site to activate the carboxylic acid groups. Subsequently, the metal-hydrogen compound (metal hydride) binds to the activated carboxylic acid, aldehyde, or ketone groups, converting them into alcohol groups.

[0042] At the same time, as in the selective hydrogenation reaction disclosed in the present invention to convert a carboxylic acid group (-(C=O)OH), an aldehyde group (-(C=O)H), or a ketone group (-(C=O)-) into an alcohol group (-OH), the properties of the metal will vary with the change in the metal composition, resulting in differences in hydrogen adsorption strength, adsorption amount, etc. In fact, when comparing Ru-Sn and Ni-Sn metals for similar carboxylic acid group reduction reactions, the use of Ni metal may lead to the problem of requiring longer reaction times and higher reaction temperatures under similar conditions. This is because Ru metal has a superior hydrogen adsorption capacity than Ni metal.

[0043] Specifically, in the hydrogenation catalyst, the content of ruthenium is 30% by weight or more and less than 55% by weight, based on the total weight of ruthenium and tin, and the content of tin is greater than 45% by weight and less than 70% by weight, based on the total weight of ruthenium and tin. More specifically, the content of ruthenium can be 30.5% by weight or more, or 30.8% by weight or more, and 54.5% by weight or less, or 53% by weight or less, or 50% by weight or less, or 47% by weight or less. The content of tin can be 45.5% by weight or more, or 47% by weight or more, or 50% by weight or more, or 53% by weight or more, and 69.5% by weight or less, or 69.2% by weight or less.

[0044] In addition, the hydrogenation catalyst according to one embodiment of the present disclosure is characterized in that the content of ruthenium as a catalytically active metal is within the range of effectively exerting a catalytic effect. Specifically, based on the total weight of the catalyst, the content of ruthenium as a catalytically active metal can be more than 1 part by weight and less than 11 parts by weight. More specifically, based on the total weight of the catalyst, the content of ruthenium as a catalytically active metal can be more than 1.5 parts by weight and less than 10.5 parts by weight, or more than 2 parts by weight and less than 10 parts by weight, or more than 3.5 parts by weight and less than 9.5 parts by weight, or more than 4.5 parts by weight and less than 9 parts by weight, or more than 4.8 parts by weight and less than 8 parts by weight, or more than 5.0 parts by weight and less than 7.5 parts by weight, or more than 5.1 parts by weight and less than 7 parts by weight. Especially when the content of ruthenium is high, that is, when the content of ruthenium exceeds 11 parts by weight, there is a disadvantage of rising catalyst prices. In addition, as the size of the active metals (including ruthenium and tin) constituting the catalyst increases, the selectivity of the target product decreases, which may bring the problem of additional process costs. In addition, when the content of ruthenium is less than 1 part by weight, there may be a problem of reducing conversion efficiency, thereby reducing the production efficiency of alcohol compounds (such as 1,4-butanediol (1,4-BDO)) in the hydrogenation reaction.

[0045] Meanwhile, the content of tin as a catalytically active metal may be 1 to 12 parts by weight, or 1.5 to 11 parts by weight, or 2 to 10.8 parts by weight, or 4.5 to 10.5 parts by weight, or 5 to 10.2 parts by weight, or 5.5 to 10 parts by weight, or 5.9 to 9.8 parts by weight, based on the total weight of the catalyst.

[0046] Furthermore, the weight ratio of tin to ruthenium in the catalytically active metal may be from 0.1 to 3.0, or from 0.5 to 2.8, or from 0.8 to 2.67, or from 0.9 to 2.5, or from 1.0 to 2.4, or from 1.1 to 2.3 by weight.

[0047] The hydrogenation catalyst according to one embodiment of the present disclosure preferably contains ruthenium and tin as catalytically active metals, with their contents within the above-mentioned ranges. If the contents are below the above-mentioned ranges, the reaction conversion efficiency or selectivity of the target product may be reduced, resulting in excessive separation and recovery costs during the process. In other words, if the ruthenium content of the catalytically active metals in the hydrogenation catalyst is less than 1 part by weight, the conversion efficiency of compounds containing alcohol groups (such as 1,4-butanediol (BDO)) may be reduced during the hydrogenation reaction of carboxylic acid groups, aldehyde groups, or ketone groups to alcohol groups. On the other hand, if the content exceeds the above-mentioned ranges, the metal's dispersibility may be reduced and the crystal size may increase, which may also lead to reduced conversion efficiency.

[0048] At the same time, the particle size of the active metal in the hydrogenation catalyst can be about 3nm to about 15nm, specifically, about 3.5nm to about 14nm, or about 4nm to about 13nm, or about 4.2nm to about 12nm, or about 4.3nm to about 11nm, or about 4.4nm to about 10nm. The particle size of the metal can be the average value of the measured particle size, for example, it can be the particle size value of 100 samples measured by transmission electron microscopy. Specifically, the average particle size of the active metal can be about 3.8nm to about 12nm, or about 4.0nm to about 10nm, or about 4.2nm to about 9nm, or about 4.3nm to about 8nm, or about 4.5nm to about 7.5nm. For example, the particle size of the active metal in the hydrogenation catalyst can be about 3nm to about 6nm, and the average particle size of the active metal can be about 4nm to about 5nm; alternatively, the particle size of the active metal in the hydrogenation catalyst can be about 4nm to about 12nm, and the average particle size of the active metal can be about 7nm to about 8nm.

[0049] Specifically, a hydrogenation reaction using the catalyst disclosed herein is, for example, a reaction in which a dicarboxylic acid is converted into a linear alcohol by selective hydrogenation. In such a hydrogenation reaction, the catalyst serves as a medium to absorb hydrogen as a reducing agent and provide it to the reactants. If hydrogen transfer is not smooth, a reverse reaction (oxidation reaction) of the conversion product may occur. Therefore, in order to efficiently carry out the forward hydrogenation reaction, the content of ruthenium and tin as catalytically active metals is preferably within the above-mentioned content range.

[0050] Meanwhile, the hydrogenation catalyst according to one embodiment of the present disclosure is characterized in that, as described above, the contents of ruthenium and tin as catalytically active metals are within a specific range, and ruthenium and tin form a homogeneous alloy state, and the ratio (A2 / A1) of the hydrogen adsorption amount (A2) of the catalyst at a temperature of 523 K or less to the total hydrogen adsorption amount (A1) measured by H2-TPR (hydrogen temperature-programmed reduction) analysis is 70 mol% to 99 mol%.

[0051] H2-TPR (temperature-programmed reduction) analysis is a method that measures the desorption / adsorption behavior of gases as the catalyst temperature changes. The adsorption behavior can vary depending on the type of metal, loading, and distribution. In particular, even if ruthenium and tin meet a specific weight ratio in the catalyst, if the metals segregate rather than form an alloy, catalytic activity can drop dramatically.

[0052] Specifically, for the hydrogenation catalyst, the ratio (A2 / A1) of the hydrogen adsorption amount (A2) at temperatures below 523 K measured by H2-TPR (Hydrogen Temperature Programmed Reduction) analysis to the total hydrogen adsorption amount (A1) of the catalyst can be 75 mol% or more, or 80 mol% or more, or 82 mol% or more, or 85 mol% or more, or 87 mol% or more, and 98 mol% or less, or 97 mol% or less, or 96 mol% or less, or 95 mol% or less, or 94.5 mol% or less.

[0053] The specific method for H2-TPR (Hydrogen Temperature Programmed Reduction) analysis of the hydrogenation catalyst according to an embodiment of the present disclosure is shown in Example 1 and will be described in detail later.

[0054] For example, Hydrogen Temperature Programmed Reduction (H2-TPR) analysis is an analytical method for evaluating the amount of hydrogen adsorbed by a metal at a specific reaction temperature, and its specific measurement method is as follows.

[0055] <H2-TPR Analysis Method>

[0056] - Pretreatment: Catalyst pretreatment and TCD signal stabilization

[0057] ① Pass an inert gas (Ar or N2) through the layer containing the catalyst and heat it to 373 K at a rate of 5 K / min;

[0058] ② Keep the inert gas flowing through the catalyst layer at 373 K for 30 minutes;

[0059] ③ Cool to 323 K while passing the inert gas through the catalyst layer;

[0060] ④ Stabilize the TCD signal by passing a mixed gas of an inert gas and hydrogen through the catalyst layer for 60 minutes. At this time, the volume ratio of the inert gas to H2 is fixed at 1:0.05.

[0061] [[ID=2Z]]- H2-TPR Analysis

[0062] ① Analysis gas: 5% H2 / Ar mixed gas, at 30 sccm (standard cubic centimeters per minute).

[0063] ② Heat to 1073 K at a rate of 5 K per minute.

[0064] More specifically, in the present disclosure, the area bounded by the H2-TPR curve and the baseline, corresponding to the total amount of hydrogen adsorbed (in moles) by the passivation layer containing the catalyst, from the initial temperature of 333 K to the metal reduction temperature of 973 K, can be defined as A1. The area bounded by the H2-TPR curve and the baseline, corresponding to the amount of hydrogen adsorbed (in moles) by the passivation layer containing the catalyst within the hydrogenation reaction temperature range, from the initial temperature of 333 K to the hydrogenation reaction temperature of 523 K, can be defined as A2. The ratio (mol %) of A2 to A1 can then be measured.

[0065] By performing H2-TPR analysis according to the above method, the ratio of the amount of hydrogen adsorbed at temperatures below 523 K to the total amount of hydrogen adsorbed on the catalyst can be measured.

[0066] Specifically, during hydrogenation reactions to convert carboxylic acid, aldehyde, or ketone groups into alcohols, the catalyst absorbs hydrogen. Hydrogen adsorbed on the catalyst above the reaction temperature does not participate in the reaction, so the amount of hydrogen adsorbed / desorbed at temperatures below 523 K significantly affects the reaction activity. Therefore, for hydrogenation catalysts, the amount of hydrogen adsorbed at temperatures below 523 K must fall within the above range in the H2-TPR spectrum.

[0067] For example, the hydrogen adsorption curve of the hydrogenation catalyst passivation layer can be used to predict the performance of the catalyst during hydrogenation reaction.

[0068] Specifically, the catalyst performance in the present disclosure is measured in a batch reactor for liquid-phase hydrothermal reactions, so catalyst reduction prior to activity evaluation can be performed ex situ. Specifically, since metallic catalysts are flammable, they can be treated after reduction and then stabilized by passivation. Specifically, the catalyst according to one embodiment of the present disclosure converts reactants into target products through a hydrogenation reaction. In this case, the most important role is the hydrogen adsorption behavior characteristics.

[0069] For example, since the passivated catalyst is introduced into the reactor before the catalytic reaction, and the hydrogen is pressurized after being heated to the reaction temperature (503 K, Kelvin temperature), hydrogen adsorbed at temperatures above approximately 523 K cannot participate in the reaction. Furthermore, in the catalytic reaction mechanism, hydrogenation occurs on the Ru-Sn metal surface. In other words, if Ru-Sn forms a separate metallic phase instead of an alloy, byproducts such as γ-butyrolactone or byproducts from the gasification reaction will be produced instead of being converted into the desired product, 1,4-butanediol.

[0070] Therefore, when the Ru–Sn metals are fully mixed, a single hydrogen adsorption peak appears in the H2-TPR analysis, and its peak width is determined by the difference in heating rate (5 °C / min) and the size of the Ru–Sn metals.

[0071] Therefore, the hydrogen adsorption curve of the passivation layer of the hydrogenation reaction catalyst according to one embodiment of the present disclosure can predict the hydrogen adsorption curve of the ruthenium-tin composite metal (Ru—Sn alloy) participating in the actual catalytic reaction.

[0072] Specifically, even if similar hydrogen adsorption curves are shown by H2-TPR (hydrogen temperature programmed reduction) analysis, there may be limitations in the metal systems that can participate in hydrogenation reactions as hydrogenation catalysts. Typically, noble metal systems such as Pd, Ru, Ni, and Pt exhibit similar hydrogen adsorption behavior ranges in a single catalyst, but their activation ability for carbonyls (C=O) in reactants is poor, resulting in decreased catalytic activity. That is, in order to carry out an effective reduction reaction through the hydrogenation reaction pathway of the carbonyl, as described above, it is necessary to carry out an activation reaction by an oxophilic metal (such as tin) to promote hydrogen adsorption onto the carbonyl (C=O) within the optimal range by a composite metal catalyst (Ru-Sn) of ruthenium and tin containing ruthenium and tin as catalytically active metals.

[0073] However, in order to enhance overall process stability or reaction efficiency, the hydrogenation catalyst according to one embodiment of the present disclosure may further include, in addition to the ruthenium and tin mentioned above as catalytically active metals, one or more metals selected from palladium (Pd), rhodium (Rh), platinum (Pt), iron (Fe), rhenium (Re), and gallium (Ga). When such additional catalytically active metals are included, for example, when Pt is additionally included, higher performance can be achieved by promoting the reduction of tin species and preventing tin leaching during the reaction.

[0074] When one or more additional transition metals selected from palladium (Pd), rhodium (Rh), platinum (Pt), iron (Fe), rhenium (Re) and gallium (Ga) are contained as catalytically active metals in addition to ruthenium and tin, the amount of the one or more metals (in terms of their atomic ratio to ruthenium) is preferably 5 or less, or 0.1 to 5, more preferably 2 or less, or 0.2 to 2. For example, the atomic ratio of the one or more additional transition metals from palladium (Pd), rhodium (Rh), platinum (Pt), iron (Fe), rhenium (Re) and gallium (Ga) (ruthenium:additional transition metal atomic ratio) based on the ruthenium (Ru) atomic ratio may be 1:5 or less, or 1:0.001 to 1:5, preferably 1:0.1 to 1:5, more preferably 1:2 or less, or 1:0.2 to 1:2.

[0075] However, when such additional metals are included, there is a disadvantage of increasing the overall manufacturing cost of the catalyst. Specifically, a hydrogenation catalyst according to one embodiment of the present disclosure is characterized in that it contains ruthenium and tin as catalytically active metals within a specific range, optimizes the hydrogen adsorption amount according to H2-TPR (hydrogen temperature-programmed reduction) analysis, and forms a homogeneous alloy state, thereby achieving better hydrogenation reaction performance without using the above-mentioned expensive Pt (which is about twice the price of Ru), as described above, and does not cause Sn leaching during the reaction.

[0076] Therefore, the hydrogenation catalyst according to one embodiment of the present disclosure preferably contains only ruthenium and tin as catalytically active metals.

[0077] Meanwhile, the catalytically active metals are supported on a porous carbon-based support.

[0078] According to one embodiment of the present disclosure, a ruthenium and tin composite metal catalyst (Ru-Sn), containing ruthenium and tin as catalytically active metals within an optimal range, is suitable for use on a porous carbon-based support, particularly a carbon-based support, because in practical applications, hydrogenation reactions are carried out under high-temperature hydrothermal reaction conditions. Conventional alumina- or silica-based supports are unstable under hydrothermal reaction conditions and undergo phase transitions, significantly reducing catalytic activity when used as a catalyst support.

[0079] The porous carbon-based carrier is not particularly limited, but at least one selected from activated carbon, carbon black, graphite, graphene, ordered mesoporous carbon (OMC) and carbon nanotubes can be used. Preferably, carbon black having a high proportion of mesopores in all pores can be used. In specific examples, activated carbon can be SX ULTRA, CGSP, PK1-3, SX 1G, DRACO S51HF, CA-1, A-51, GAS1240PLUS, KBG, CASP and SX PLUS, etc., and carbon black can be BLACK and etc., but not limited to.

[0080] For example, a porous carbon-based support may have a pore volume of 0.1 cm 3 / g to 1.5cm 3 / g, or 0.3cm 3 / g to 1.5cm 3 / g, or 0.6cm 3 / g to 1.5cm 3 / g.

[0081] Here, in the carbon-based support, the proportion of the volume of mesopores having a pore diameter of 2 nm to 50 nm in the total pore volume may be 50% or more. Preferably, in the carbon support, the proportion of the volume of mesopores of carbon in the total pore volume may be 70% or more; more preferably, in the carbon support, the proportion of the volume of mesopores of carbon in the total pore volume may be 75% or more.

[0082] At this time, if the mesopore volume ratio is lower than 50%, there may be problems with the microscopic mass transfer rate of reactants and products within the carbon support; if the average pore size is greater than 50 nm, there may be a problem of low physical strength of the support, so the above range is appropriate.

[0083] In addition, the carbon-based supports include ordered mesoporous carbon (OMC) with a BET surface area of 100 m 2 / g to 1500m 2 Preferably, the carbon may comprise ordered mesoporous carbon (OMC) having a BET specific surface area of 200 m 2 / g to 1000m 2 / g range.

[0084] At this time, if the specific surface area of the carbon-based support is less than 100 m 2 / g, it may be difficult to achieve high dispersion of active metals (Ru, Sn), and if the specific surface area of carbon exceeds 1500m 2 / g, there may be a problem of reduced mesopore ratio, so the above range is appropriate.

[0085] At the same time, the BET specific surface area of the hydrogenation catalyst can be 100m 2 / g to 1500m 2 / g, or 200m 2 / g to 1,500m 2 / g, or 350m 2 / g to 800m 2 / g, or 550m 2 / g to 670m 2 / g.

[0086] In addition, the average pore size of the hydrogenation catalyst may be from 2.0 nm to 5.5 nm, or from 2.5 nm to 5.0 nm, or from 3.0 nm to 4.8 nm, or from 4.0 nm to 4.5 nm.

[0087] According to the hydrogenation catalyst of one embodiment of the present disclosure, by containing catalytically active metals ruthenium and tin within a specific range and forming a homogeneous alloy state of ruthenium and tin, carboxylic acid groups, aldehyde groups or ketone groups can be effectively hydrogenated directly into alcohol groups (e.g., primary alcohols) without the need for esterification reaction, and in this hydrogenation reaction, it can achieve high selectivity and conversion rate under relatively low pressure conditions without the need for excessively long reaction time or high temperature conditions.

[0088] Preparation method of hydrogenation catalyst

[0089] Therefore, according to another embodiment of the present disclosure, a method for preparing the above-mentioned hydrogenation catalyst is provided.

[0090] Specifically, the method for preparing the hydrogenation catalyst comprises:

[0091] preparing a metal precursor solution by dissolving one or more precursor compounds comprising ruthenium as a catalytically active metal and one or more precursor compounds comprising tin as a catalytically active metal in an acidic aqueous solution; and

[0092] After drying the metal precursor solution or the mixture comprising the metal precursor solution, performing a reduction treatment in the presence of hydrogen;

[0093] Wherein, in the metal precursor solution, based on the total weight of ruthenium and tin, the content of ruthenium is greater than 30 weight % and less than 55 weight %, and the content of tin is greater than 45 weight % and less than 70 weight %.

[0094] Specifically, the precursor compound containing ruthenium as the catalytically active metal is at least one selected from metallic ruthenium, ruthenium chloride, ruthenium nitrate, ruthenium acetylacetonate, ruthenium carbonyl, ruthenium oxalate, and ruthenium nitrosyl nitrate.

[0095] Furthermore, the precursor compound containing tin as a catalytically active metal is at least one selected from tin(II) chloride, sodium stannate, tin(II) acetate, tin fluoride, and tin iodide.

[0096] In the method for preparing a hydrogenation catalyst according to the present disclosure, a precursor compound containing ruthenium and tin or a mixture thereof is completely dissolved using an acidic aqueous solution, thereby completely ionizing the precursor compound to prepare a metal precursor solution. By using this acidic aqueous solution, ruthenium and tin do not solidify in a separate state, but can form an alloy in the form of a solid solution. Due to this characteristic, a broad and symmetrical hydrogen adsorption peak can be confirmed in the hydrogen adsorption curve of the hydrogenation catalyst according to an embodiment of the present disclosure. Therefore, the hydrogenation catalyst according to an embodiment of the present disclosure can achieve excellent hydrogenation reaction performance without the additional use of expensive Pt or the like, and also has the excellent effect of no Sn leaching during the reaction process.

[0097] However, if an acidic aqueous solution is not used when preparing the metal precursor solution, Sn and Ru will be loaded in a segregated state, which can lead to decreased catalytic activity even when using the same amount of metal precursor compounds. The hydrogen adsorption curve of the final catalyst will show independent hydrogen adsorption peaks for Ru and Sn, and the reduction mechanism of the carboxylic acid groups on the composite metal (Ru-Sn) phase will not proceed normally, resulting in low efficiency of this type of catalytic reaction.

[0098] Such acidic aqueous solutions may comprise one or more of hydrochloric acid, nitric acid and acetic acid, and an acidic aqueous solution having a concentration of 0.1% to 10% by weight may be used to fully dissolve the precursor compound or a mixture thereof. For example, deionized water comprising 1% to 5% by weight of hydrochloric acid may be used as the acidic aqueous solution. In the method for preparing a hydrogenation catalyst, if an excessive amount of an acidic aqueous solution is used, corrosive gases such as HCl may be excessively produced during the subsequent reduction treatment, thereby causing corrosion of the reactor or process and possibly poisoning the catalyst. Therefore, it is preferred to use the minimum content within the above range.

[0099] Furthermore, in the metal precursor solution, the ruthenium content is 30 wt% or more and less than 55 wt% based on the total weight of ruthenium and tin, and the tin content is greater than 45 wt% and less than 70 wt% based on the total weight of ruthenium and tin.

[0100] In the metal precursor solution, the goal is to form a homogeneous alloy state of ruthenium and tin in the final composite metal catalyst while containing the catalytically active metals ruthenium and tin within a specific optimized range.

[0101] Specifically, based on the gross weight of the prepared catalyst, the ruthenium content in the metal precursor solution can be more than 1 part by weight and less than 11 parts by weight. More specifically, based on the gross weight of the prepared catalyst, the ruthenium content in the metal precursor solution can be more than 1.5 parts by weight and less than 10.5 parts by weight, or more than 2 parts by weight and less than 10 parts by weight, or more than 3.5 parts by weight and less than 9.5 parts by weight, or more than 4.5 parts by weight and less than 9 parts by weight, or more than 4.8 parts by weight and less than 8 parts by weight, or more than 5.0 parts by weight and less than 7.5 parts by weight, or more than 5.1 parts by weight and less than 7 parts by weight. Especially, when ruthenium content is high, for example, when ruthenium content exceeds 11 parts by weight, there is a problem of increased catalyst price. In addition, due to the increase in size of the active metal (including ruthenium and tin) constituting the catalyst, the selectivity of the target product can be reduced, and therefore there may be a problem of increased process cost. In addition, when the ruthenium content is less than 1 part by weight, there is a problem in that conversion efficiency in a hydrogenation reaction may be reduced, resulting in reduced production efficiency of a compound containing an alcohol group, such as 1,4-butanediol (BDO).

[0102] Also, the tin content in the metal precursor solution may be 1 to 11 parts by weight, or 2 to 10.8 parts by weight, or 4.5 to 10.5 parts by weight, or 5 to 10.2 parts by weight, or 5.5 to 10 parts by weight, or 5.9 to 9.8 parts by weight, based on the total weight of the prepared catalyst.

[0103] In addition, the weight ratio of the tin content to the ruthenium content in the metal precursor solution may be 0.8 to 2.67, or 0.9 to 2.5, or 1.0 to 2.4, or 1.1 to 2.3. If the weight ratio is higher than the above range, an alloy of ruthenium and tin is not formed, but exists as independent metals, which reduces the efficiency of the carbonyl selective reduction reaction and may lead to a decrease in conversion efficiency because the conversion proceeds to an intermediate esterified compound such as γ-butyrolactone (GBL) or an ether compound such as tetrahydrofuran (THF) instead of the target product, that is, a compound containing an alcohol group such as 1,4-butanediol (BDO).

[0104] In the metal precursor solution, more specific content ranges and weight ratios of ruthenium and tin as catalytically active metals can be used so that the final prepared composite metal catalyst reaches the level within the aforementioned range for the hydrogenation catalyst, and the specific details are omitted here.

[0105] Meanwhile, the method for preparing a hydrogenation catalyst according to the present disclosure is characterized in that, in order to make the content of ruthenium and tin contained in the catalyst reach the specific optimized range as described above, ruthenium and tin precursors are loaded by an impregnation method (e.g., incipient wetness impregnation method), and then dried and reduced to prepare the ruthenium and tin precursors.

[0106] Specifically, the method for preparing a hydrogenation catalyst may further include, after preparing the metal precursor solution as described above, mixing the metal precursor solution with a porous carbon-based support. This mixing step may be part of the step of loading ruthenium and tin as catalytically active metals on the porous carbon-based support.

[0107] The specific types and physical property ranges of the porous carbon-based support may be as described above, and thus a detailed description thereof is omitted.

[0108] Specifically, the metal precursor solution or the mixture comprising the metal precursor solution may be dried at a temperature of 323K to 473K and then subjected to a reduction treatment, ie, a reduction reaction may be performed at a temperature of 473K to 773K in the presence of hydrogen.

[0109] In addition, the method for preparing a hydrogenation catalyst disclosed herein may further include, after the reduction treatment, a step of passivating a reduced product obtained by the reduction treatment to form a passivation layer.

[0110] The passivation step is to passivate the reduction product with a nitrogen mixed gas containing 0.1 to 20 volume percent of oxygen.

[0111] Hydrogenation method

[0112] According to yet another embodiment of the present disclosure, a hydrogenation method is provided for performing a hydrogenation reaction using the above catalyst.

[0113] The hydrogenation method according to the present disclosure is characterized in that a hydrogenation reaction of converting a carboxylic acid group, an aldehyde group, or a ketone group into an alcohol group is performed in the presence of the aforementioned hydrogenation catalyst.

[0114] Specifically, in the hydrogenation reaction, the reaction pressure may be 50 bar to 150 bar, the reaction temperature may be 410 K to 560 K, and the reaction time may be 0.5 hour to 10 hours.

[0115] At the same time, the hydrogenation reaction can be carried out using a carboxylic acid compound containing a carboxylic acid group, wherein the carboxylic acid compound is at least one selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic 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, cyclohexanecarboxylic acid, benzoic acid and anhydrides thereof. Specifically, the carboxylic acid compound containing a carboxylic acid functional group can be one or more selected from succinic acid, succinic anhydride, maleic acid and maleic anhydride, or two or more.

[0116] In addition, the hydrogenation reaction can be carried out using an aldehyde compound containing an aldehyde group, wherein the aldehyde compound is at least one selected from the group consisting of formaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, 2-methylbutyraldehyde, 3-methylbutyraldehyde, 2,2-dimethylpropionaldehyde, hexanal, 2-methylvaleraldehyde, 3-methylvaleraldehyde, 4-methylvaleraldehyde, 2-ethylbutyraldehyde, 2,2-dimethylbutyraldehyde, 3,3-dimethylbutyraldehyde, octanal, decanal, and glutaraldehyde. Specifically, the aldehyde compound containing an aldehyde group can be n-butyraldehyde.

[0117] In addition, the hydrogenation reaction can be carried out using a ketone compound containing a ketone group, wherein the ketone compound is at least one selected from acetone, butanone, pentanone, hexanone, cyclohexanone and acetophenone. Specifically, the ketone compound containing a ketone group can be butanone.

[0118] Meanwhile, the hydrogenation reaction may have a conversion rate represented by the following Formula 1 of 70% or more, or 70% or more to 100%.

[0119] [Formula 1]

[0120] Conversion (%) = moles of reactants consumed / moles of reactants supplied × 100.

[0121] In Formula 1, the number of moles of reactant supplied represents the number of moles of the compound containing a carboxylic acid group, an aldehyde group, or a ketone group supplied to the hydrogenation reaction, and the number of moles of reactant consumed represents the number of moles of the compound containing a carboxylic acid group, an aldehyde group, or a ketone group consumed in the hydrogenation reaction.

[0122] The conversion rate is a value calculated as the molar ratio of the reactant consumed in the hydrogenation reaction to the reactant containing a carboxylic acid group, an aldehyde group, or a ketone group supplied to the hydrogenation reaction when a compound containing an alcohol group is obtained through a hydrogenation reaction. The conversion rate is preferably 90% or higher, or 90% or higher to 99.9%.

[0123] In addition, the hydrogenation reaction may have a selectivity expressed by the following Formula 2 of 50% or more, or 50% or more to 90%.

[0124] [Formula 2]

[0125] Selectivity (%) = number of moles of the compound containing an alcohol group / total number of moles of the product × 100.

[0126] In Formula 2, the total molar number of products represents the total molar number of products generated by the hydrogenation reaction, and the molar number of compounds containing alcohol groups represents the molar number of compounds containing alcohol groups converted from carboxylic acid groups, aldehyde groups or ketone groups in the products generated by the hydrogenation reaction.

[0127] The selectivity is a value calculated from the molar ratio of the alcohol group-containing compound corresponding to the target compound of the present disclosure in the product produced by the hydrogenation reaction. The selectivity is preferably 55% or more, or 55% or more to 70%.

[0128] In addition, the hydrogenation reaction may have a yield represented by the following Formula 3 of 50% or more, or 50% or more to 90%.

[0129] [Formula 3]

[0130] Yield (%) = Conversion rate (%) of formula 1 × Selectivity (%) of formula 2 / 100

[0131] The yield is a value calculated from the yield of the compound containing an alcohol group produced by the hydrogenation reaction. The yield is preferably 55% or more, or 55% or more to 70%.

[0132] Specifically, the hydrogenation catalyst according to one embodiment of the present disclosure can achieve the high selectivity and conversion rate as described above in the hydrogenation reaction of converting carboxylic acid groups, aldehyde groups or ketone groups into alcohol groups under relatively low pressure conditions without excessive reaction time or high temperature conditions, and ensure a high yield of alcohol compounds, with excellent results.

[0133] The present invention will be described in more detail below by way of examples. However, the following examples are only used to illustrate the present invention, and the scope of the present invention is not limited to these examples.

[0134] [Example]

[0135] Example 1

[0136] Activated carbon (pore volume: 0.65 cm 3 Here, the porous carbon support was prepared by drying the porous carbon support in a drying oven at 373 K (Kelvin temperature) for 24 hours to remove residual moisture absorbed in the carbon support.

[0137] In addition, about 0.65 g of tin (II) chloride (SnCl2·2H2O) was completely dissolved using an acidic aqueous solution containing hydrochloric acid. At this time, the acidic aqueous solution was prepared by adjusting the total concentration to 1 weight % using 35% hydrochloric acid (reagent grade product). About 0.03 g of ruthenium chloride (RuCl3·3H2O, wherein ruthenium metal is equivalent to about 80 weight % of tin metal) was mixed with the tin precursor solution and completely dissolved for about 3 hours. At this time, the weight ratio of ruthenium / (ruthenium + tin) in the metal precursor solution was 44.4 weight %.

[0138] The metal precursor solution prepared above was evenly mixed with the porous carbon support using a mortar and pestle. The evenly mixed metal-carbon mixture was then placed in a drying oven set at a temperature of 373K and dried for 12 hours or longer. The dried metal-carbon mixture was then reduced at a temperature of 623K under a hydrogen flow for about 3 hours to prepare a powdered phase hydrogenation catalyst. After reduction, the powdered catalyst was passivated for 3 hours using a nitrogen mixed gas containing 1% oxygen to prepare a passivated catalyst. The resulting powdered hydrogenation catalyst (i.e., the passivated catalyst) was then used to perform a catalyst activity test.

[0139] For the powdered hydrogenation catalyst (ie, passivated catalyst) prepared in Example 1, the ratio of the hydrogen adsorption amount below 523 K to the total hydrogen adsorption amount of the passivated catalyst was measured by H2-TPR analysis according to the following method.

[0140] Specifically, hydrogen temperature-programmed reduction (H2-TPR) analysis is an analytical method for evaluating the amount of hydrogen adsorbed by a metal at a specific reaction temperature, and its detailed measurement method is as follows.

[0141] <H2-TPR Analysis Method>

[0142] -Pretreatment: Catalyst pretreatment and TCD signal stabilization

[0143] ①Let an inert gas (Ar or N2) flow through the layer containing the catalyst and heat it to 373K at a rate of 5K / min;

[0144] ②Keep the inert gas flowing through the catalyst layer at 373K for 30 minutes;

[0145] ③Cool to 323K while allowing the inert gas to flow through the catalyst layer;

[0146] ④Stabilize the TCD signal by allowing a mixed gas of inert gas and hydrogen to flow through the catalyst layer for 60 minutes. At this time, the volume ratio of the inert gas to H2 is fixed at 1:0.05.

[0147] -H2-TPR Analysis

[0148] ①Analysis gas: 5% H2 / Ar mixed gas, at 30 sccm (standard cubic centimeters per minute).

[0149] ②Heat to 1073K at a rate of 5K per minute.

[0150] As described above, Figure 1 shows the hydrogen adsorption curve of the passivation layer containing the powdered hydrogenation catalyst (i.e., the passivated catalyst) of Example 1, which was obtained by performing H2-TPR analysis on the powdered hydrogenation catalyst (i.e., the passivated catalyst) of Example 1.

[0151] Figure 1 In, corresponding to the temperature range from the initial temperature of 333K to the metal reduction temperature of 973K, the area of the total hydrogen adsorption amount (in moles) adsorbed by the passivation layer enclosed by the H2-TPR curve and the baseline is defined as A1. Corresponding to the temperature range from the starting temperature of 333K to the hydrogenation reaction temperature of 523K, the area of the hydrogen adsorption amount (in moles) within the hydrogenation reaction temperature range enclosed by the H2-TPR curve and the baseline is defined as A2. Then, the ratio of A2 to A1 (mol%) is shown in Table 1. That is, A2 / A1 measured in Example 1 is 94.5 mol%.

[0152] In addition, the metal content in the catalyst was analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). The specific surface area and average pore diameter of the catalyst were measured by nitrogen adsorption-desorption analysis.

[0153] Therefore, in the powdered hydrogenation catalyst of Example 1 (i.e., the passivated catalyst), the ruthenium content was measured to be 51,600 ppm by weight of the total catalyst, and the tin content was measured to be 59,120 ppm by weight of the total catalyst. Furthermore, the size of the catalytically active metal particles was measured by transmission electron microscopy (TEM) to be approximately 3.5 nm to 5.5 nm, with an average particle size of approximately 4.5 nm. Furthermore, the BET specific surface area of the powdered hydrogenation catalyst was measured to be 603 m 2 The measured average pore size of the powdered hydrogenation catalyst was 4.1 nm. The specific physical property measurement results of the powdered hydrogenation catalyst of Example 1 are shown in Table 1 below.

[0154] Example 2

[0155] The powdered hydrogenation catalyst of Example 2 was prepared by performing the same drying, reduction, and passivation processes as in Example 1, except that the weight ratio of ruthenium / (ruthenium + tin) (i.e., Ru / Ru + Sn) in the metal precursor solution was changed to 31 wt % and uniformly mixed with the porous carbon support.

[0156] Figure 1 3 shows the hydrogen adsorption curve of the passivation layer comprising the powdered hydrogenation catalyst (ie, the passivated catalyst) prepared in Example 2, analyzed by H2-TPR using the above method.

[0157] In addition, the physical properties of the powdered hydrogenation catalyst (i.e., passivated catalyst) of Example 2 were evaluated using the same method as in Example 1. Specifically, in the powdered hydrogenation catalyst of Example 2, the ruthenium content was measured to be 52,480 ppm by weight of the total catalyst, and the tin content was 117,700 ppm by weight of the total catalyst. Transmission electron microscopy (TEM) measurement showed that the size of the catalytically active metal was approximately 5 nm to 10 nm, with an average particle size of approximately 7.5 nm. In addition, the BET specific surface area of the powdered hydrogenation catalyst was measured to be 573 m 2 The measured average pore size of the powdered hydrogenation catalyst was 4.3 nm. The specific physical property measurement results of the powdered hydrogenation catalyst of Example 2 are shown in Table 1 below.

[0158] Comparative Example 1

[0159] The powdered hydrogenation catalyst of Comparative Example 1 was prepared by performing the same drying, reduction, and passivation processes as in Example 1, except that the weight ratio of ruthenium / (ruthenium + tin) (i.e., Ru / Ru + Sn) in the metal precursor solution was changed to 24 wt % and uniformly mixed with the porous carbon support.

[0160] Figure 1 3 shows the hydrogen adsorption curve of the passivation layer comprising the powdered hydrogenation catalyst (ie, the passivated catalyst) prepared in Comparative Example 1, which was analyzed by H2-TPR using the above method.

[0161] In addition, the physical properties of the powdered hydrogenation catalyst (ie, passivated catalyst) of Comparative Example 1 were evaluated using the same method as in Example 1. The measurement results are shown in Table 1 below.

[0162] Comparative Example 2

[0163] The powdered hydrogenation catalyst of Comparative Example 2 was prepared by performing the same drying, reduction, and passivation processes as in Example 1, except that the weight ratio of ruthenium / (ruthenium + tin) (Ru / Ru+Sn) in the metal precursor solution in Example 1 was changed to 100 wt % and uniformly mixed with the porous carbon support.

[0164] Figure 1 3 shows the hydrogen adsorption curve of the passivation layer comprising the powdered hydrogenation catalyst (ie, the passivated catalyst) prepared in Comparative Example 2, which was analyzed by H2-TPR using the above method.

[0165] In addition, the physical properties of the powdered hydrogenation catalyst (ie, passivated catalyst) of Comparative Example 2 were evaluated using the same method as in Example 1. The measurement results are shown in Table 1 below.

[0166] Comparative Example 3

[0167] The powdered hydrogenation catalyst of Comparative Example 3 was prepared by performing the same drying, reduction, and passivation processes as in Example 1, except that ruthenium metal was added to the metal precursor solution to achieve a ruthenium / (ruthenium + tin) weight ratio (i.e., Ru / Ru + Sn) of 47 wt %. The metal precursor solution was prepared using an aqueous solution (i.e., deionized water) without hydrochloric acid, instead of the acidic aqueous solution of Example 1. This solution was then uniformly mixed with a porous carbon support to prepare the powdered hydrogenation catalyst of Comparative Example 3.

[0168] Figure 1 3 shows the hydrogen adsorption curve of the passivation layer comprising the powdered hydrogenation catalyst (ie, the passivated catalyst) prepared in Comparative Example 3, which was analyzed by H2-TPR using the above method.

[0169] In addition, the physical properties of the powdered hydrogenation catalyst (ie, passivated catalyst) of Comparative Example 3 were evaluated using the same method as in Example 1. The measurement results are shown in Table 1 below.

[0170] Table 1 lists the weight ratios of the metal components Ru and Sn in the metal precursor solutions in Examples 1 to 2 and Comparative Examples 1 to 3, and the physical properties of the powdered hydrogenation catalysts.

[0171] [Table 1]

[0172]

[0173]

[0174] In Table 1, the ratio A2 / A1 is the ratio of the amount of hydrogen adsorbed within the hydrogenation reaction temperature (A2) to the total amount of hydrogen adsorbed on the hydrogenation catalyst (A1). Specifically, the total amount of hydrogen adsorbed (A1) is calculated from the area corresponding to the amount of hydrogen adsorbed (in moles) in the range of 333K to 973K measured by TPR analysis. The amount of hydrogen adsorbed within the hydrogenation reaction temperature (A2) is calculated from the area corresponding to the amount of hydrogen adsorbed (in moles) in the range of 333K to 523K measured by TPR analysis. A2 / A1 is the percentage of A2 to A1.

[0175] <Experimental Example 1>

[0176] Using each of the powdered hydrogenation catalysts of Examples 1 and 2 and Comparative Examples 1 to 3, a succinic acid hydrogenation reaction was conducted according to the following method. During the succinic acid hydrogenation reaction, the succinic acid conversion (mol %), selectivity for the main compound in the product (mol %), and yield (%) of 1,4-butanediol for each catalyst were measured using the following methods. The measurement results are shown in Table 2 below.

[0177] Specifically, the hydrogenation reaction of succinic acid was carried out using a batch reactor. First, 0.75 g of a powdered hydrogenation catalyst was placed in an autoclave reactor, and succinic acid having a concentration of 2 wt% mixed with 150 mL of 1,4-dioxane solvent was added thereto.

[0178] To minimize oxidation and other side reactions, hydrogen was used as the reaction medium, and the air inside the reactor was purged. The reactor was then fixed and stirred at 300 rpm while the internal temperature was raised to 503 K. Once the reaction temperature was reached, the hydrogen was pressurized to 90 bar, and the stirring speed was increased to 1000 rpm. The hydrogenation reaction was then allowed to proceed for 6 hours. During this time, reactant samples were collected at various times using a sampling port on the reactor.

[0179] The products obtained after the reaction were analyzed using gas chromatography (GC) equipped with an Agilent DB-FFAP, HP-5 column. The conversion of succinic acid, product selectivity, and yield of 1,4-butanediol were calculated using the following equations 1a to 3a, respectively.

[0180] [Formula 1a]

[0181] Succinic acid conversion rate (%) = moles of succinic acid consumed / moles of succinic acid supplied×100.

[0182] [Formula 2a]

[0183] 1,4-Butanediol selectivity (%) = number of moles of 1,4-butanediol in the product / total number of moles of the product×100.

[0184] [Formula 3a]

[0185] 1,4-Butanediol yield (%) = succinic acid conversion (%) × 1,4-butanediol selectivity (%) / 100.

[0186] [Table 2]

[0187]

[0188] As shown in Table 2, when the hydrogenation reaction of succinic acid was carried out using the catalysts of Examples 1 to 2 according to the present disclosure, which contained ruthenium and tin within predetermined ranges as catalytically active metals and formed a homogeneous alloy state of ruthenium and tin, compared to Comparative Examples 1 to 3, 1,4-butanediol as an alcohol compound could be produced with high yield, high selectivity, and high conversion, while minimizing conversion to γ-butyrolactone (GBL) or tetrahydrofuran (THF).

Claims

1. A hydrogenation catalyst comprising ruthenium and tin as catalytically active metals, in, Based on the total weight of ruthenium and tin, the content of ruthenium is 30 weight % or more and less than 55 weight %, and the content of tin is greater than 45 weight % and less than 70 weight %; The hydrogen adsorption ratio (A2 / A1) of the hydrogenation catalyst is 70 mol% to 99 mol%, and the hydrogen adsorption ratio (A2 / A1) is measured by hydrogen temperature-programmed reduction (H2-TPR) analysis, which is the ratio of the hydrogen adsorption amount (A2) of the hydrogenation catalyst at a temperature below 523K to the total hydrogen adsorption amount (A1) of the hydrogenation catalyst.

2. The hydrogenation catalyst according to claim 1, in, The content of ruthenium as a catalytically active metal is 1 part by weight or more and 11 parts by weight or less based on the total weight of the hydrogenation catalyst; The content of tin as a catalytically active metal is 1 part by weight or more and 12 parts by weight or less based on the total weight of the hydrogenation catalyst; The weight ratio of tin to ruthenium in the catalytically active metal is 0.1 to 3.0 by weight.

3. The hydrogenation catalyst according to claim 1, wherein The catalytically active metal is supported on a porous carbon-based support.

4. The hydrogenation catalyst according to claim 3, wherein The porous carbon-based support includes at least one selected from activated carbon, carbon black, graphite, graphene, ordered mesoporous carbon (OMC), and carbon nanotubes.

5. The hydrogenation catalyst according to claim 3, wherein The pore volume of the porous carbon-based support is 0.1 cm 3 / g to 1.5cm 3 / g.

6. The hydrogenation catalyst according to claim 1, wherein The BET specific surface area of the hydrogenation catalyst is 100 m 2 / g to 1500m 2 / g.

7. The hydrogenation catalyst according to claim 1, wherein The average pore diameter of the hydrogenation catalyst is 2.0 nm to 5.5 nm.

8. A method for preparing a hydrogenation catalyst, comprising: preparing a metal precursor solution by dissolving one or more precursor compounds comprising ruthenium as a catalytically active metal and one or more precursor compounds comprising tin as a catalytically active metal in an acidic aqueous solution; as well as After drying the metal precursor solution or the mixture comprising the metal precursor solution, performing a reduction treatment in the presence of hydrogen; Wherein, in the metal precursor solution, based on the total weight of ruthenium and tin, the content of ruthenium is greater than 30 weight % and less than 55 weight %, and the content of tin is greater than 45 weight % and less than 70 weight %.

9. The method for preparing a hydrogenation catalyst according to claim 8, wherein The precursor compound containing ruthenium as a catalytically active metal is at least one selected from metallic ruthenium, ruthenium chloride, ruthenium nitrate, ruthenium acetylacetonate, carbonyl ruthenium, ruthenium oxalate and ruthenium nitrosyl nitrate.

10. The method for preparing a hydrogenation catalyst according to claim 8, wherein The precursor compound containing tin as a catalytically active metal is at least one selected from tin (II) chloride, sodium stannate, tin (II) acetate, tin fluoride and tin iodide.

11. The method for preparing a hydrogenation catalyst according to claim 8, further comprising the step of mixing the metal precursor solution with a porous carbon-based support after preparing the metal precursor solution.

12. The method for preparing a hydrogenation catalyst according to claim 8, wherein After the metal precursor solution or the mixture containing the metal precursor solution is dried at a temperature of 323K to 473K, a reduction treatment is performed at a temperature of 473K to 773K in the presence of hydrogen.

13. The method for preparing a hydrogenation catalyst according to claim 8, wherein: The method further includes the step of passivating a reduction product obtained by the reduction treatment to form a passivation layer after the reduction treatment.

14. The method for preparing a hydrogenation catalyst according to claim 13, wherein: The passivation step is to passivate the reduction product using a nitrogen mixed gas containing 0.1 to 20 volume percent of oxygen.

15. A hydrogenation method comprising: In the presence of the catalyst according to claim 1, a hydrogenation reaction is carried out to convert the carboxylic acid group, aldehyde group or ketone group into an alcohol group.

16. The hydrogenation method according to claim 15, wherein The hydrogenation reaction is carried out under the conditions of a reaction pressure of 50 bar to 150 bar and a reaction temperature of 410K to 560K, and the reaction time is 0.5 hour to 10 hours.

17. The hydrogenation method according to claim 15, wherein: The hydrogenation reaction is carried out using a carboxylic acid compound containing a carboxylic acid group, wherein the carboxylic acid compound is at least one selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic 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, cyclohexanecarboxylic acid, benzoic acid and its anhydride.

18. The hydrogenation method according to claim 15, wherein The hydrogenation reaction is carried out using an aldehyde compound containing an aldehyde group, wherein the aldehyde compound is at least one selected from formaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, 2-methylbutyraldehyde, 3-methylbutyraldehyde, 2,2-dimethylpropionaldehyde, hexanal, 2-methylvaleraldehyde, 3-methylvaleraldehyde, 4-methylvaleraldehyde, 2-ethylbutyraldehyde, 2,2-dimethylbutyraldehyde, 3,3-dimethylbutyraldehyde, octanal, decanal and glutaraldehyde.

19. The hydrogenation method according to claim 15, wherein: The hydrogenation reaction is carried out using a ketone compound containing a ketone group, wherein the ketone compound is at least one selected from acetone, butanone, pentanone, hexanone, cyclohexanone and acetophenone.

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