CN119585044A

CN119585044A - Metal-supported catalyst, method for producing alcohol, and hydrogenation method

Info

Publication number: CN119585044A
Application number: CN202380055325.7A
Authority: CN
Inventors: 远藤浩悦; 下川隆一
Original assignee: Mitsubishi Chemical Corp
Current assignee: Mitsubishi Chemical Corp
Priority date: 2022-07-25
Filing date: 2023-07-24
Publication date: 2025-03-07
Also published as: KR20250041124A; WO2024024750A1; JPWO2024024750A1

Abstract

一种金属负载催化剂，是将钌、锡以及铂负载于载体的、用于羧酸和/或羧酸酯的氢化的金属负载催化剂，所述金属负载催化剂还负载有铁、以及铬和/或钼。能提供在维持高的催化活性的状态下副产物产率更低的催化剂、以及使用该催化剂的由羧酸和/或羧酸酯来制造醇的醇的制造方法、以及羧酸和/或羧酸酯的氢化方法。A metal-supported catalyst is a metal-supported catalyst for hydrogenating carboxylic acid and/or carboxylic acid ester, wherein ruthenium, tin and platinum are supported on a carrier, and the metal-supported catalyst is also supported with iron, chromium and/or molybdenum. A catalyst having a lower by-product yield while maintaining high catalytic activity, a method for producing alcohol from carboxylic acid and/or carboxylic acid ester using the catalyst, and a method for hydrogenating carboxylic acid and/or carboxylic acid ester can be provided.

Description

Metal-supported catalyst, process for producing alcohol, and hydrogenation process

Technical Field

The present invention relates to a metal-supported catalyst, and more particularly, to a metal-supported catalyst capable of hydrogenating carboxylic acid and/or carboxylic acid ester with high selectivity, a process for producing alcohol using the metal-supported catalyst, and a hydrogenation process.

Background

As a catalyst for reducing carboxylic acid and/or carboxylic ester to the corresponding alcohol, a catalyst obtained by supporting ruthenium, tin, and platinum on a carrier and subjecting the supported ruthenium, tin, and platinum to a reduction treatment with hydrogen or the like has been proposed (for example, patent documents 1 and 2). The catalyst shows high reactivity and reaction selectivity in the hydrogenation of carboxylic acid and/or carboxylic acid ester, and is a good catalyst.

Patent document 3 discloses a catalyst in which iron is also supported on a reduction catalyst. More specifically, a supported catalyst in which nitrates of iron, cobalt and nickel are added to a reduction catalyst in which ruthenium, platinum and tin are supported as main component metals is disclosed, and a process for producing 1, 4-cyclohexanedimethanol is disclosed.

Prior art literature

Patent literature

Patent document 1 Japanese patent application laid-open No. 2001-9277

Patent document 2 International publication No. 2015/178459

Patent document 3 specification No. 104722321 of Chinese patent

Disclosure of Invention

Problems to be solved by the invention

When the hydrogenation reaction of carboxylic acid and/or carboxylic acid ester is carried out using the catalysts described in patent documents 1 and 2 known heretofore, although the hydrogenation activity is high, by-products accompanied by cleavage of c—c bond and c—o bond are produced, the yield of the target product is lowered, and a precise operation for removing the by-products is sometimes required.

The catalyst disclosed in patent document 3 suppresses the formation of by-products, but the catalyst is insufficient in extent, and further improvement is desired, as compared with the catalysts described in patent documents 1 and 2.

In view of the above-described circumstances, the technical problem of the present invention is to provide a catalyst having a lower by-product yield in a state where a high catalytic activity is maintained.

Solution for solving the problem

The present inventors have found that a metal-supported catalyst in which ruthenium, tin, and platinum are supported on a carrier and iron, chromium, and/or molybdenum are also supported can greatly reduce the yield of byproducts while maintaining high catalytic activity.

The details thereof are not clear, but it is presumed that iron, chromium and molybdenum exhibit an effect of selectively inhibiting active sites that break c—c bonds and c—o bonds but not inhibiting active sites that reduce carbonyl groups on the catalyst, and particularly, it is found that the above-mentioned effects can be remarkably exhibited by a combination of iron and chromium, a combination of iron and molybdenum, and a combination of three components of iron, chromium and molybdenum.

The gist of the present invention is as follows.

[1] A metal-supported catalyst for hydrogenation of carboxylic acids and/or carboxylic acid esters, wherein ruthenium, tin and platinum are supported on a carrier, and wherein iron, chromium and/or molybdenum are also supported on the metal-supported catalyst.

[2] The metal-supported catalyst according to the above [1], wherein the iron content is 0.01 mass% or more and 4 mass% or less, and the total content of chromium and/or molybdenum is 0.01 mass% or more and 2 mass% or less, based on the total mass of the metal-supported catalyst.

[3] The metal-supported catalyst according to the above [1] or [2], wherein the carrier is a carbonaceous carrier.

[4] The metal-supported catalyst according to any one of the above [1] to [3], wherein the total loading amount of ruthenium, tin, platinum, iron, molybdenum and chromium is 5 mass% or more with respect to the total mass of the metal-supported catalyst.

[5] The metal-supported catalyst according to any one of the above [1] to [4], wherein the metal-supported catalyst is produced by hydrogen reduction.

[6] A process for producing an alcohol, wherein the metal-supported catalyst of any one of [1] to [5] is brought into contact with a carboxylic acid and/or a carboxylic acid ester and the carboxylic acid and/or the carboxylic acid ester is reduced to obtain an alcohol corresponding to each of the carboxylic acid and/or the carboxylic acid ester.

[7] A method for hydrogenating carboxylic acid and/or carboxylic acid ester, comprising contacting the metal-supported catalyst of any one of the above [1] to [5] with carboxylic acid and/or carboxylic acid ester.

[8] The method for producing an alcohol according to the above [6], wherein the carboxylic acid is 1, 4-cyclohexanedicarboxylic acid and the carboxylic acid ester is 1, 4-cyclohexanedicarboxylic acid ester.

Effects of the invention

According to the present invention, a catalyst having a lower byproduct yield while maintaining a high catalytic activity, a method for producing an alcohol from a carboxylic acid and/or a carboxylic acid ester using the catalyst, and a method for hydrogenating a carboxylic acid and/or a carboxylic acid ester can be provided.

Detailed Description

The following description will be given in detail of the embodiments of the present invention, but the following description of the constituent elements is an example (representative example) of the embodiments of the present invention, and the present invention is not limited to these matters, and can be implemented by various modifications within the scope of the gist thereof.

In the present application, metals used as a support (metals such as ruthenium, tin, platinum, and other iron used as needed) may be collectively referred to as "metal components". The metal-supported catalyst is generally referred to as "a metal-supported catalyst" as a material obtained by supporting the metal component on a carrier, a material obtained by subjecting the metal component to a reduction treatment, and a material obtained by further subjecting the metal component to an oxidation stabilization treatment. The catalyst in which a metal component is further supported in the "metal-supported catalyst" subjected to the oxidation stabilization treatment is also referred to as a "metal-supported catalyst". The catalyst at a stage prior to the reduction treatment in the metal-supported catalyst may be referred to as a "metal support".

[ Metal Supported catalyst ]

The metal-supported catalyst of the present invention (hereinafter, may be simply referred to as "the present catalyst") is usually obtained by subjecting a metal-supported material having the above metal component supported on a carrier to a reduction treatment with a reducing gas. The metal-supported catalyst of the present invention is also a material obtained by oxidizing the metal-supported catalyst subjected to the reduction treatment. Further, a substance to which a metal component is further added after these treatments is also included in the metal-supported catalyst.

The metal-supported catalyst of the present invention is a catalyst containing ruthenium, tin, and platinum as essential elements (hereinafter, sometimes referred to as a "reduction catalyst"), and the reduction catalyst is also supported with iron, chromium, and/or molybdenum. Specifically, there are combinations of iron and chromium, combinations of iron and molybdenum, and combinations of three components of iron, chromium and molybdenum. By producing the metal-supported catalyst having such a constitution, the yield of by-products accompanied by cleavage of C-C bonds and C-O bonds can be suppressed to be lower while maintaining the hydrogenation activity.

For example, when 1, 4-cyclohexanedicarboxylic acid is hydrogenated as a carboxylic acid, cyclohexane methanol accompanied by C-C cleavage and 4-methylcyclohexane methanol accompanied by C-O cleavage are produced together with 1, 4-cyclohexanedimethanol as a target product, and the yield of the target product is lowered. In contrast, by using the catalyst of the present invention, the formation of by-products can be effectively suppressed.

In addition, 1, 4-cyclohexanedimethanol, which is a diol compound, is often used as a raw material for resins such as polyesters and polyurethanes, and in this case, monohydric alcohols such as cyclohexanedimethanol and 4-methylcyclohexanemethanol act as polymerization inhibitors, and therefore, it is necessary to avoid mixing during resin synthesis and to perform a removal operation. On the other hand, when the amount of by-product produced in the hydrogenation reaction becomes small, there is an advantage that the purification operation for removing the monohydric alcohol can be simplified or skipped.

< Vector >

The carrier used in the present invention is not particularly limited as long as it has a large surface area and can support a metal component, and examples thereof include carbonaceous carriers such as activated carbon and carbon black, inorganic porous carriers such as alumina, silica, diatomaceous earth, zirconium dioxide, titanium dioxide and hafnium dioxide, and silicon carbide and gallium nitride. Among them, the carbonaceous carrier such as activated carbon, graphite, black lead, etc., titanium dioxide, zirconium dioxide are preferable, and the carbonaceous carrier is more preferable from the viewpoint of excellent stability and easy industrial availability, and the activated carbon is more preferable from the viewpoint of high surface area, excellent dispersibility of metal, and easy improvement of reactivity. The carrier may be used alone or in combination of two or more.

The carrier may be used as it is or may be pretreated to a form suitable for loading. For example, in the case of using a carbonaceous carrier, the carbonaceous carrier may be heat-treated with nitric acid as described in Japanese patent application laid-open No. 10-71332. By the above method, the dispersibility of the metal component on the carrier can be improved, and the activity of the obtained catalyst can be improved.

The shape of the support and the size of the support used in the present invention are not particularly limited, and when the shape is converted into a spherical shape, the average primary particle diameter is usually 50 μm or more and 5mm or less, preferably 4mm or less. The particle size was measured by the screening test method described in JIS standard JIS Z8815.

The appropriate particle diameter of the carrier varies depending on the reaction using the catalyst, and is therefore preferably adjusted according to the reaction. Specifically, in the case where the reaction using the present catalyst is a complete mixing reaction, the particle diameter of the carrier is usually 50 μm or more, preferably 100 μm or more, usually 3mm or less, preferably 2mm or less. The smaller the particle diameter of the carrier, the higher the activity per unit mass of the resulting catalyst is, which is preferable in this respect, but when the particle diameter of the carrier is too small, the reaction solution may be difficult to separate from the catalyst. That is, when the particle diameter of the carrier is not less than the above-mentioned lower limit, it is preferable in terms of reactivity, and when the particle diameter of the carrier is not more than the above-mentioned upper limit, it is preferable that it is easy to separate from the reaction liquid.

When the shape of the support is not a spherical shape, the volume of the support is obtained, and the volume is converted into the diameter of spherical particles of the same volume.

In the case where the reaction using the present catalyst is a fixed bed reaction, the particle diameter of the carrier is usually 0.5mm or more and 5mm or less, preferably 4mm or less, and more preferably 3mm or less. When the particle diameter of the carrier is not less than the above-mentioned lower limit, the operation is not difficult due to the differential pressure, and when the particle diameter of the carrier is not more than the above-mentioned upper limit, the sufficient reactivity can be obtained.

< Metal component >

The metal-supported catalyst of the present invention is a catalyst in which ruthenium, tin, and platinum are supported on a carrier as essential elements, and iron, chromium, and/or molybdenum (hereinafter, sometimes referred to as "other metals such as iron") are also supported on the catalyst. By additionally loading iron and chromium and/or molybdenum, the formation of by-products can be further suppressed. In terms of the by-product formation inhibitory effect, a higher effect can be obtained by loading iron, and chromium and/or molybdenum.

Further, as long as the reaction such as the reduction reaction using the catalyst is not adversely affected, other metals may be further contained as needed, in addition to ruthenium, tin, platinum, iron, chromium, and molybdenum, and at least one metal selected from the group consisting of rhodium, tungsten, rhenium, barium, and boron may be preferably contained, and rhenium is more preferably contained.

The raw materials for each metal component are described below.

(Loading of Metal component)

The loading of the metal component of the catalyst is not particularly limited, and is determined for each metal. The ruthenium loading is usually 1 mass% or more, preferably 3 mass% or more, usually 10 mass% or less, preferably 8 mass% or less, based on the mass ratio of the total mass of the metal-supported catalyst. Similarly, the tin loading is usually 1 mass% or more, preferably 2 mass% or more, and usually 15 mass% or less, preferably 10 mass% or less, based on the mass ratio of the total mass of the metal-supported catalyst. In addition, similarly, the platinum loading is usually 0.5 mass% or more, usually 7 mass% or less, preferably 5 mass% or less, in terms of mass ratio relative to the total mass of the metal-supported catalyst. When the content is within these ranges, the ability as a hydrogenation catalyst is improved, and thus it is preferable. The loading of iron, chromium and/or molybdenum is preferably 0.01 mass% or more and4 mass% or less, more preferably 2 mass% or less, respectively. By setting the range to this level, the production of by-products can be significantly reduced. That is, the iron loading is preferably 0.01 mass% or more and4 mass% or less, and more preferably 0.01 mass% or more and 2 mass% or less. In the case of supporting chromium and/or molybdenum, the suitable supporting amount of each metal is in the range of 0.01 mass% or more and4 mass% or less, more preferably 0.01 mass% or more and 2 mass% or less. In the case of supporting both chromium and molybdenum, the total supporting amount of both is preferably in the above range. In order to sufficiently obtain the effect of suppressing by-products by the combination of iron and chromium, the composition ratio is not particularly limited as long as it is the above-mentioned range, and for example, 100:1 to 1:100, more preferably 10:1 to 1:10, still more preferably 10:1 to 1:5 is used. In addition, the same range is preferable in the case of using iron and molybdenum in combination. On the other hand, chromium and molybdenum are more expensive than iron in terms of cost, and therefore are preferably less than iron in this sense.

The total amount of the other metals such as ruthenium, tin, platinum, and iron is not particularly limited, but is usually 5 mass% or more, preferably 8 mass% or more, more preferably 10 mass% or more, and is usually 40 mass% or less, preferably 30 mass% or less, more preferably 20 mass% or less, based on the total mass of the metal-supported catalyst.

The metal loading is a value obtained by converting all of the loaded metal into metal atoms. The size of the reduced metal-supported catalyst of the present invention is not particularly limited, and is substantially the same as the size of the above-mentioned carrier.

The amount of the supported metal (hereinafter, sometimes referred to as "metal") can be measured by, for example, the following method. The catalyst may be pulverized and stirred to form a uniform state, and if necessary, the catalyst may be made into a disk, and the catalyst may be analyzed by fluorescent X-ray analysis while maintaining a solid state. Alternatively, the alkali may be decomposed by melting or by pressure decomposition using microwaves to prepare a homogeneous solution, and the solution may be analyzed by ICP emission spectrometry (high-frequency inductively coupled plasma emission spectrometry).

Among them, ICP emission spectrometry (high-frequency inductively coupled plasma emission spectrometry) is preferable in terms of obtaining a measurement result with higher accuracy by preparing a uniform solution.

< Method for producing catalyst >

In the present invention, the method for producing a catalyst includes a step of supporting the metal component on a carrier (hereinafter referred to as a metal supporting step), and a step of reducing the obtained metal support with a reducing gas. Each step will be described below in order.

Metal loading procedure ]

The metal loading step is a step of loading the metal component on the carrier to obtain a metal loaded product. The method for supporting the metal component is not particularly limited, and a known method can be used. At the time of loading, a solution or dispersion of various metal compounds as raw materials of the above-mentioned metal components may be used.

(Metal loading method)

The method for supporting the metal component on the support is not particularly limited, and various impregnation methods can be generally applied. For example, there are an adsorption method of adsorbing a metal ion having a saturation adsorption amount or less by using the adsorption force of the metal ion to the carrier, an equilibrium adsorption method of immersing the carrier in a solution having a saturation adsorption amount or more of the metal ion to remove an excess solution, a pore-filling method of adding a solution having the same amount of the metal ion as the pore volume of the carrier to adsorb the whole solution to the carrier, a incipient wetness impregnation (INCIPIENT WETNESS) method of adding the solution of the metal ion until the solution is commensurate with the water absorption amount of the carrier and ending in a state where the surface of the carrier is uniformly wetted and the excess solution is not present, an evaporation dry solid method of impregnating the solution of the metal ion to the carrier and evaporating the solvent while stirring, a spray method of drying the carrier and spraying the solution.

Among the above methods, the pore filling method, the incipient wetness impregnation method, the evaporation dry solidification method, and the spray method are preferable, and the pore filling method, the incipient wetness impregnation method, and the evaporation dry solidification method are more preferable. By the above method, other metal components such as ruthenium, tin, platinum, and iron can be supported in a relatively uniformly dispersed state.

The load may be carried out at once after the whole metal solution to be carried is prepared, or may be carried separately for each metal. In the case of the split load, the load may be split for each type, or may be split with a plurality of metal solutions. In order to shorten the loading step, it is preferable to load all the metal solutions at once or to load the metal solutions separately from each other with a plurality of metals. The time point of the split loading is not particularly limited, and the multiple metals may be loaded only several times, may be split loaded after the middle of the process from the loading to the hydrogen reduction, or may be split loaded on the metal-supported catalyst after the hydrogen reduction.

(Metal Compound)

The metal compound to be used for the loading is not particularly limited, and may be appropriately selected according to the loading method. For example, halides such as chlorides, bromides and iodides, inorganic acid salts such as nitrates and sulfates, organic acid salts such as acetates, metal hydroxides, metal oxides, organometallic compounds, metal complexes and the like can be used. Among them, halides, inorganic acid salts, organic acid salts, and the like are preferable, halides and inorganic acid salts are more preferable, halides are further preferable, and chlorides such as hydrochloride are particularly preferable among the halides. Further, at least one of the above metal compounds is preferably a chloride, and more preferably all of it is a chloride. It is considered that by using the chloride, the metal is complexed in a solution state, and the dispersion state of each metal on the supported carrier becomes uniform, thereby stably supporting. In addition, the growth of alloy particles based on ruthenium, tin, platinum, iron and other metal components in the obtained catalyst is inhibited, the activity and selectivity are improved, and the stability of the catalyst in the reaction is improved.

More specifically, ruthenium is exemplified by ruthenium chloride, ruthenium nitrosylnitrate, ruthenium tris (acetylacetonate), and the like. These ruthenium salts may be used singly or in combination of two or more.

In the case of tin, specific examples thereof include tin compounds such as tin (II) chloride, tin (IV) chloride, tin (II) acetate, tin (IV) acetate, dibutyltin dilaurate, dibutyltin oxide, and dibutyldimethoxy tin. The tin compound may be used alone or in combination of two or more.

In the case of platinum, a platinum precursor compound is used, and examples of the platinum precursor compound include hexachloroplatinic acid (such as hexahydrate), potassium tetrachloroplatinate (II), potassium hexachloroplatinate (IV), potassium tetracyanopylatinate (II), sodium hexachloroplatinate (hexahydrate), platinum (IV) hexahydroxide acid, potassium tetracyanopylatinate (II) (hydrate), and tetrabutylammonium hexachloroplatinate (IV). The platinum precursor compound may be used alone or in combination of two or more.

As other metal compounds such as iron, specifically, iron salts, chromium compounds, and molybdenum compounds exemplified below can be used.

As the iron salt, an iron salt selected from the group consisting of ferric chloride, ferric nitrate, ferric sulfate, and ferric acetylacetonate is preferably used.

As the chromium compound, inorganic acid salts such as chromium nitrate, chromium sulfate and chromium chloride, organic acid salts such as chromium acetate, chromium oxalate and chromium acetylacetonate, and various chromium compounds known for use in the production of chromium oxide catalysts can be used.

The molybdenum compound is preferably a molybdenum compound containing molybdenum element in an oxidized state, and examples thereof include molybdenum trioxide, molybdic acid, molybdate, and heteropolyacid. Among them, molybdenum trioxide and molybdate are more preferable. Examples of the molybdate include ammonium paramolybdate, ammonium dimolybdate, and ammonium tetramolybdate. One kind of molybdenum material may be used, or two or more kinds may be used in combination.

(Solvent)

When the above metal compound is supported on a carrier, the metal compound can be dissolved or dispersed using various solvents for various supporting methods. The type of the solvent to be used in this case is not particularly limited as long as the metal compound can be dissolved or dispersed, and the firing and hydrogen reduction of the metal support to be carried out later and the hydrogenation reaction using the catalyst of the present application are not adversely affected, and examples thereof include ketone solvents such as acetone, alcohol solvents such as methanol and ethanol, ether solvents such as tetrahydrofuran and ethylene glycol dimethyl ether, and water. These solvents may be used alone or as a mixed solvent. In the present application, as described above, as the metal compound, a halide is preferably used, a chloride is more preferably used, and water is preferably used in order to make the solubility of these halides high.

In addition, various additives may be added in addition to the solvent when dissolving or dispersing the metal compound. For example, as described in JP-A-10-15388, the dispersibility of each metal component on the carrier can be improved when the carrier is loaded by adding a carboxylic acid and/or carbonyl compound solution.

< Metal Supports >

The metal support having the metal component supported thereon may be dried as needed, and is preferably dried. In the case where the metal support is subjected to the subsequent reduction treatment in an undried state, the reactivity may be reduced, and particularly in the case where the dehalogenation treatment described later is performed subsequently, drying is preferable in view of suppressing elution of the metal salt in the presence of a base that is generally used for the dehalogenation treatment.

The drying method is not particularly limited as long as the solvent or the like used in the removal of the load can be removed. Usually in the presence or flow-through of an inert gas.

The pressure at which the drying is carried out is not particularly limited, and is usually carried out under normal pressure or reduced pressure.

The temperature at which the drying is performed is not particularly limited, and is usually 300 ℃ or less, preferably 250 ℃ or less, more preferably 200 ℃ or less, and usually 80 ℃ or more.

< Dehalogenation treatment and cleaning >

The metal support may be dehalogenated, if necessary, before the reduction step described below. In the metal loading step, particularly when a halide such as a chloride is used as a raw material of the metal component, a halogen compound may be generated in a reduction apparatus in a reduction step described later. Although this is not a problem in terms of the laboratory-scale throughput, in the case of reduction treatment in a large amount in industry, a large amount of halogen compounds are generated in the reduction device, and it is sometimes necessary to treat the exhaust gas, and corrosion of the device may occur. Therefore, it is preferable to perform the dehalogenation treatment before the reduction step.

The method of dehalogenation is not particularly limited, and the metal support may be generally contacted with an alkaline compound in a gas phase or a liquid phase to react a halide in the metal support, and then removed by gas phase treatment or washing. Among them, from the viewpoint of ease of handling and good efficiency of halide removal from the metal support, it is preferable to perform the treatment by contacting with the basic compound in the liquid phase and then remove it by washing. Specifically, it is more preferable to conduct water washing after contact with an alkaline aqueous solution.

The dehalogenation treatment temperature is not particularly limited, and is usually 10 ℃ or higher, preferably 20 ℃ or higher, and is usually 150 ℃ or lower, preferably 100 ℃ or lower, and more preferably 80 ℃ or lower. When the dehalogenation temperature is not lower than the above-mentioned lower limit, dehalogenation can be efficiently performed, and when the dehalogenation temperature is not higher than the above-mentioned upper limit, volatilization, thermal decomposition, etc. of a solvent or an alkali compound used for the treatment do not occur.

When an alkaline aqueous solution is used in the dehalogenation treatment, the pH of the alkaline aqueous solution is not particularly limited, and is usually 7.5 or more, preferably 8.0 or more, usually 13.0 or less, preferably 12.5 or less. When the pH of the alkaline aqueous solution is equal to or lower than the upper limit, there is no concern that the supported metal will deteriorate due to an excessively high pH, and elution of the supported metal is not likely to occur in a washing process described later. When the pH of the alkaline aqueous solution is equal to or higher than the lower limit, sufficient dehalogenation can be performed.

Examples of the alkali compound include alkali metal carbonates, hydrogencarbonates, ammonia, ammonium carbonate, and ammonium hydrogencarbonate. These may be used alone or in combination of two or more. Among them, a weakly basic alkali compound is preferable. The use of a weakly basic alkali compound such as ammonia or an ammonium salt tends to give a catalyst having high activity as compared with the use of a strongly basic alkali compound.

The amount of the alkali compound is usually 0.1 to 50 equivalents, preferably 1 to 20 equivalents, and more preferably 1 to 10 equivalents, based on the halogen ions contained in the carrier. The alkali compound is usually used in the form of an aqueous solution, but a water-soluble solvent such as methanol, ethanol, acetone, and ethylene glycol dimethyl ether, and a mixed solvent of these solvents with water may be used. The alkaline aqueous solution is preferably used in an amount of completely filling pores of the metal-supported carrier of the metal support, that is, in an amount of not less than the pore volume of the carrier. The amount of the alkaline aqueous solution to be used is not particularly limited, since it depends on the concentration of the alkaline aqueous solution, and is usually 0.8 to 20 times, preferably 1 to 10 times, more preferably 1 to 5 times, the pore volume of the support of the metal support to be used.

The metal support subjected to the treatment with the alkali compound is preferably washed to remove the excess alkali compound and the halide formed. In the washing, any solution in which an excessive alkali compound or a generated halide is dissolved may be used, and among them, water is preferable. In this case, the cleaning temperature is not particularly limited, and the cleaning is usually performed at 10 ℃ or higher and 100 ℃ or lower, but is preferably 40 ℃ or higher, more preferably 50 ℃ or higher, in view of good cleaning efficiency in warm water.

Further drying may be performed as needed after the alkali treatment or after the washing. As the drying conditions, the same conditions as those for drying the above-mentioned metal support can be used.

< Reduction treatment and reducing gas >

The metal support is preferably subjected to a reduction treatment with a reducing gas to prepare a metal-supported catalyst. The reducing gas in the present application is not particularly limited as long as it is a substance having reducing property, and for example, hydrogen, methanol, hydrazine, or the like is used, and hydrogen is preferable. That is, the metal-supported catalyst of the present application is preferably prepared by hydrogen reduction.

In the reduction treatment in the present invention, a reduction reaction occurs regardless of the type of the reducing gas, and the metal-supported catalyst is obtained. The amount of the reducing gas required for the reduction treatment is described as "hydrogen absorption amount".

In the present invention, the reduction treatment of the metal load may be performed in one stage, or may be performed in a plurality of stages.

(Reduction treatment temperature)

In the production of the metal-supported catalyst of the present invention, the reduction treatment is preferably performed by controlling the treatment temperature range.

The reduction treatment temperature is not particularly limited, and may be a constant temperature or may be a temperature that varies. Typically 80 ℃ or more, preferably 100 ℃ or more, more preferably 150 ℃ or more, typically 650 ℃ or less, preferably 600 ℃ or less, more preferably 580 ℃ or less. When the reduction treatment temperature is not higher than the upper limit temperature, the metal component is not sintered and the carrier is not adversely affected, whereas when the reduction treatment temperature is not lower than the lower limit temperature, the reduction reaction proceeds sufficiently.

Specifically, the reduction treatment may be performed at a specific temperature in a preferable temperature range for a predetermined period of time, or may be performed at a temperature in a preferable temperature range while raising the temperature for a predetermined period of time. In view of the efficiency of the reaction time, the reduction treatment is preferably performed while the temperature of the reaction system is raised for a predetermined period of time, because the metal load generates heat due to the reduction treatment. On the other hand, in the case of involving intense heat generation, a method of holding at a constant temperature is preferable in order to accurately control the reaction.

(Concentration of reducing gas)

The concentration of the reducing gas in the reduction treatment of the catalyst is not particularly limited, and may be 100% by volume of the reducing gas or may be diluted with an inert gas. The inert gas as used herein refers to a gas that does not react with the metal carrier or the reducing gas, and includes nitrogen, water vapor, and the like, and nitrogen is generally used. The concentration of the reducing gas in the case of dilution with the inert gas is usually 5% by volume or more, preferably 15% by volume or more, more preferably 30% by volume or more, and still more preferably 50% by volume or more, relative to the total gas components. In addition, the reduction treatment may be performed by using a low concentration of the reducing gas at the initial stage of the reduction and then gradually increasing the concentration of the reducing gas.

(Flow rate)

In order to determine the flow rate of the reducing gas, it is preferable to grasp the hydrogen absorption amount at the time of catalyst reduction in advance. The method for measuring the hydrogen absorption amount is not particularly limited, and it is generally preferable to perform the reduction by a temperature programmed reduction (Temperature Programmed Reduction) method (hereinafter referred to as TPR method) which is a method of adjusting the hydrogen supply amount per unit time and the temperature increase time per unit time. By using this method, the hydrogen absorption amount and the absorption temperature of the present catalyst can be precisely measured.

In the TPR method, a catalyst to be measured is placed in a vessel, the vessel is heated while a constant flow rate of hydrogen is flowing, and the amounts of hydrogen at an inlet and an outlet of the vessel are continuously measured. By such a method, the hydrogen absorption amount at the time of reduction of the metal-supported catalyst can be grasped. Specifically, the measurement can be performed by the method described in the examples.

In the reduction treatment of the catalyst, the reducing gas may be used in a closed state in the reactor, or may be used in a flow-through state in the reactor, and preferably, the reducing gas is circulated in the reactor. By the reduction treatment, raw water, ammonium chloride, etc. are by-produced in the reactor, and these by-products may adversely affect the metal load before the reduction treatment, the metal load after the reduction treatment, and the catalyst obtained, and the flow of the reducing gas through the reactor may prevent this. That is, by flowing the reducing gas, the by-product can be discharged to the outside of the reaction system.

The amount of the reducing gas required for the reduction treatment is not particularly limited as long as the object of the present invention is achieved, and may be appropriately set according to the apparatus in which the reduction is performed, the size of the reactor in the reduction, and the flow conditions. In general, the amount of the reducing gas required for the reduction treatment is set to a flow rate of 1.5 times or more, preferably 2 times or more, more preferably 3 times or more, and particularly preferably 5 times or more the amount of hydrogen required for each reduction treatment under the condition that the contact efficiency of hydrogen with respect to the amount of hydrogen absorption obtained by the above-described TPR method is high such that the hydrogen flows through the catalyst layer. When the amount of the reducing gas required for the reduction treatment is not less than the above lower limit, the reduction proceeds sufficiently, particularly when the contact efficiency with hydrogen is sufficient. The upper limit is not particularly limited, but is usually 500 times or less, preferably 200 times or less, from the viewpoints of no problem of exhaust gas treatment, no scattering of metal carriers or produced catalysts due to the reducing gas, and avoidance of waste of excessive reducing gas.

(Reduction treatment time)

The time required for the reduction treatment varies depending on the amount of the metal load or the like to be treated, the apparatus to be used, and the like, and is usually 7 minutes or more, preferably 15 minutes or more, more preferably 30 minutes or more, still more preferably 1 hour or more, most preferably 2 hours or more, and usually 40 hours or less, preferably 30 hours or less.

The degree of reduction of the metal support can be determined by the halogen concentration in the oxidation-stabilized metal-supported catalyst after the reduction treatment described later. The halogen concentration in the metal-supported catalyst is not particularly limited, but is usually 0.8 mass% or less, more preferably 0.7 mass% or less, and still more preferably 0.5 mass% or less. When the halogen concentration is low, the dissolution of halogen into the reaction solution can be suppressed in the reduction reaction using the catalyst, and thus it is preferable. The lower limit of the halogen concentration is not particularly limited, but is usually 0.005 mass% or more, preferably 0.01 mass% or more. When the halogen concentration is within the above range, the reduction treatment of the metal carrier is sufficiently performed, and the elution of halogen into the reaction liquid can be suppressed to be low, and the activity of the reduction reaction using the catalyst is improved, the reaction selectivity is also improved, and the stability of the catalyst is also improved.

< Preferred embodiment of the production method >

The method for producing the catalyst of the present invention is preferably a method in which a reducing gas is passed through a catalyst on a stationary bed in a reduction step, a method in which a reducing gas is circulated through a catalyst placed on a tray (tray) or belt (belt), and a method in which a reducing gas is circulated through a flowing catalyst, as described above, after a metal loading step, a dehalogenation step, a cleaning step, and a reduction step. Among them, it is preferable to perform the reduction treatment while flowing the metal load in the reduction treatment. By performing the reduction treatment while flowing, the surface area of the metal carrier in contact with the reducing gas during the reduction treatment increases, and therefore the efficiency of the reduction treatment increases.

The method for carrying out the flow is not particularly limited as long as the operation of increasing the contact surface area with the reducing gas of the metal load or the like to be subjected to the reduction treatment is carried out, and examples thereof include a method of rotating a reactor to which the metal load or the like to be subjected to the reduction treatment is added and a method of introducing a device for stirring the metal load or the like in the reactor or moving the metal load in the reactor up and down.

Specific examples of the flow method include a method of treating the steel by using various kilns (heating furnaces).

Specifically, a preferable production method includes, for example, a continuous kiln and a batch kiln.

(Continuous kiln)

The continuous kiln is a kiln capable of continuously supplying a metal carrier to effect reduction and continuously discharging a reduced catalyst. Specifically, there are continuous rotary kilns, roller kilns, belt kilns, tunnel kilns, and the like, and among them, in the production method of the present invention, continuous rotary kilns are preferable in terms of high fluidity of the metal load and high contact efficiency with the reducing gas.

The operation conditions of the continuous kiln are not particularly limited as long as the conditions of the reduction treatment are satisfied, and may be appropriately set according to the apparatus used. In general, in a continuous kiln, the reducing gas is operated so as to satisfy the above-described reduction conditions by controlling the flow rate and temperature of the reducing gas.

Since the continuous kiln can continuously supply the metal load and the reducing gas, the supply method for supplying the metal load into the continuous kiln and the flow rate of the reducing gas can be controlled.

The flow rate of the reducing gas in the continuous kiln is not particularly limited, and when the amount of hydrogen required for reduction calculated by the TPR measurement of the metal load is "hydrogen absorption amount a (m ³/kg)", and the amount of metal load to be charged into the continuous kiln is B (kg/h), the hydrogen flow rate is usually (1.5×a×b) m ³/h or more, preferably (2×a×b) m ³/h or more, and more preferably (5×a×b) m ³/h or more. When the hydrogen flow rate is not less than the lower limit, a sufficient amount of hydrogen to be absorbed by the catalyst can be ensured, and the performance of the obtained catalyst can be maintained at a high level. The upper limit is not particularly limited, but in order to reduce the amount of hydrogen wasted, the upper limit is (1000 XA. Times.B) m ³/h or less, preferably (500 XA. Times.B) m ³/h or less, more preferably (300 XA. Times.B) m ³/h or less.

The flow direction of the metal load subjected to the reduction treatment in the continuous kiln and the flow direction of the reducing gas such as hydrogen can be appropriately adjusted according to the condition of the reduction treatment, and the reduction treatment can be performed in a state where the flow direction of the reducing gas and the flow direction of the metal load are parallel and countercurrent. Among them, from the viewpoint that the catalyst reaching the outlet of the continuous kiln can be contacted with high purity hydrogen, it is preferable that the flow direction of hydrogen and the flow direction of the metal load are countercurrent (opposite directions to each other).

The rotation speed of the continuous rotary kiln is not particularly limited. If the rotation speed is high, the contact efficiency between the metal support and hydrogen is good, but the catalyst is worn out, so that the rotation speed is usually 0.5rpm or more and 10rpm or less, preferably 5rpm or less.

(Intermittent kiln)

The intermittent kiln is a kiln in which a predetermined amount of a metal load can be charged into the kiln, and the temperature is sequentially raised to a target reduction temperature under the flow of a reducing gas, and reduction is performed at a predetermined temperature, and specifically, a fixed bed type heating furnace in which the metal load is charged and treated, a plate type heating furnace in which the metal load is placed on a tray and heated, a shuttle kiln in which a firing carriage is moved into and out of an electric furnace, an intermittent rotary kiln, and the like can be exemplified.

In terms of the contact efficiency between the metal carrier and the reducing gas, a fixed bed type heating furnace and a batch type rotary kiln for treating the metal carrier by filling are preferable, and in terms of uniform reduction, a batch type rotary kiln having a device for flowing the catalyst is preferable.

The continuous kiln is usually operated with a constant flow rate when introducing the reducing gas due to restrictions on the apparatus, whereas the intermittent kiln has reaction tanks for each batch, and therefore the temperature raising method, the flow rate, the concentration, and the like of the reducing gas can be changed for each batch.

(Operating conditions of intermittent kiln)

The operation conditions of the intermittent kiln are not particularly limited, and may be appropriately set according to the configuration of the apparatus and the like.

Since the batch rotary kiln preferably used in the present invention starts to rise in temperature after a predetermined amount of metal load is previously charged, the temperature rise time up to the final reduction temperature can be controlled in more detail than in the continuous rotary kiln.

The time of the reduction treatment is not particularly limited, and is usually 1 hour or more, preferably 2 hours or more, usually 40 hours or less, preferably 30 hours or less, more preferably 10 hours or less. When the time of the reduction treatment is too short of the above lower limit, a large amount of the metal load is reduced at once in the case where rapid hydrogen absorption occurs, so that the rapid heat generation may be accompanied by the occurrence of large hydrogen absorption, sintering of the catalyst may be performed, and stable operation may be difficult. When the time of the reduction treatment is not less than the lower limit, the reduction time can be ensured, the reduction is sufficient, and the sufficient reactivity and selectivity as a catalyst can be obtained.

On the other hand, when the reduction treatment time is not more than the upper limit, productivity of the catalyst can be ensured, and hydrogen is not lost, which is industrially advantageous.

In the case of using the batch rotary kiln, the concentration, flow rate, and the like of the reducing gas may be appropriately changed for each batch according to the condition of the reduction treatment.

The concentration of the reducing gas preferable in the operation of the batch rotary kiln is the same as described above.

The flow rate of the reducing gas is not particularly limited, and may be appropriately set according to the condition of the reduction reaction, and the amount of hydrogen required until the completion of the reduction is calculated by the TPR analysis of the unreduced catalyst, and is usually 5 times or more, preferably 10 times or more, and more preferably 20 times or more the amount of hydrogen required. In addition, the ratio is usually 5000 times or less, preferably 1000 times or less. If the flow rate of the reducing gas is equal to or higher than the lower limit, no hydrogen deficiency occurs, and if the flow rate of the reducing gas is equal to or lower than the upper limit, no excessive reducing gas is consumed, which is economically advantageous.

The rotation speed of the batch rotary kiln is not particularly limited, and if the rotation speed is high, the contact efficiency with hydrogen is good, but the catalyst is worn out, so that the operation is usually performed at 0.5 to 10rpm, preferably at 0.5 to 5 rpm.

(Oxidative stabilization of catalyst)

In the production of the metal-supported catalyst of the present invention, the oxidation state of the metal-supported catalyst obtained by reducing the metal-supported material is generally controlled. In particular, in the case of mass production of a catalyst, oxidation stabilization of the catalyst is preferably performed. The metal supported catalyst obtained by the reduction is in a state in which the metal component is reduced and highly dispersed. The oxidation stabilization is preferable because the possibility of metal sintering due to rapid heat generation can be reduced and the possibility of ignition (ignition of itself and ignition of surrounding combustibles in the case of a combustible carrier) can be reduced as compared with the case of taking out directly into the air. By stabilizing under controlled conditions, high dispersibility can be maintained and high activity can be exhibited in the subsequent hydrogenation reaction.

The method of the oxidation stabilization is not particularly limited, and there are a method of adding water to the catalyst or a method of adding the catalyst to water, a method of oxidation stabilization by a gas of low oxygen concentration diluted with an inert gas while flowing, a method of stabilization by carbon dioxide, and the like. Among them, the method of adding water to the catalyst or the method of adding the catalyst to water and the method of oxidation stabilization with a low oxygen concentration gas are preferable, the method of oxidation stabilization with a low oxygen concentration gas is more preferable (hereinafter referred to as "slow oxidation method"), and oxidation stabilization by flowing a low oxygen concentration gas is more preferable.

The oxygen concentration at the time of oxidation stabilization with a low oxygen concentration gas is not particularly limited, but is usually 0.2% by volume or more, preferably 0.5% by volume or more, and 10% by volume or less, preferably 8% by volume or less, and more preferably 7% by volume or less, as the oxygen concentration at the time of start of slow oxidation. When the oxygen concentration is equal to or higher than the lower limit, the time for complete oxidation stabilization can be shortened and stabilization can be sufficient. On the other hand, when the oxygen concentration is not more than the above-mentioned upper limit, the catalyst does not reach a high temperature, and therefore there is no fear of deactivation. In order to prepare a gas having a low oxygen concentration, air is preferably diluted with an inert gas, and nitrogen is preferably used as the inert gas.

The oxygen concentration at the time of slow oxidation may be maintained at the time of starting the slow oxidation, but if the catalyst internal temperature is high, the oxygen concentration may be increased slowly after starting the slow oxidation without causing deterioration of the catalyst.

The temperature of the catalyst is preferably controlled to not more than 130 ℃ when the slow oxidation at low oxygen concentration stabilizes. When the temperature of the catalyst is 130 ℃ or less, rapid oxidation does not proceed, and thus sintering of the catalyst does not proceed, and the strength of the carrier is not lowered, and is maintained. From the above point of view, the oxygen concentration and flow rate are preferably controlled so that the temperature of the catalyst is more preferably not more than 120 ℃, and still more preferably not more than 110 ℃.

Examples of the method for oxidation stabilization with a low oxygen concentration gas include a method of passing a low oxygen concentration gas through a catalyst on a fixed bed, a method of passing a low oxygen concentration gas through a catalyst placed on a tray or a belt, and a method of passing a low oxygen concentration gas through a catalyst.

The more excellent the dispersibility of the supported metal on the metal-supported catalyst is, the more rapidly the oxidation stabilization proceeds and the more the oxygen reacts, and therefore, among the above methods, a method of passing a gas having a low oxygen concentration through the catalyst on a fixed bed, a method of passing a gas having a low oxygen concentration through a flowing catalyst are preferable, and a method of passing a gas having a low oxygen concentration through a flowing catalyst is more preferable.

(Method for preserving catalyst)

When the metal-supported catalyst of the present invention is stored, it is preferable to store the catalyst in an atmosphere having an oxygen concentration of 15% by volume or less. When the oxidation proceeds slowly even after the oxidation stabilization by storing in such an atmosphere, the oxidation can proceed slowly in the closed container. The lower limit of the oxygen concentration is not particularly limited, but is usually preferably 0.2% by volume or more for oxidation.

In addition, the catalyst stabilized with a gas is extremely high in hygroscopicity, and causes serious problems in a nonaqueous reaction, and therefore, it is preferable to store in a closed container.

< Use >

The catalyst of the present invention is suitable as a catalyst for reduction reactions, for example, for hydrogenation of carboxylic acids and/or carboxylic acid esters. That is, the metal-supported catalyst of the present invention is preferably used in a process for producing an alcohol by bringing a carboxylic acid and/or a carboxylic acid ester into contact with the catalyst and reducing the carboxylic acid and/or the carboxylic acid ester to obtain an alcohol corresponding to each of the carboxylic acid and/or the carboxylic acid ester. The carboxylic acid or carboxylic acid ester to be subjected to the reduction reaction may be any carboxylic acid or carboxylic acid ester that is industrially easily available.

Examples of carboxylic acids which can be supplied to the reduction reaction using the catalyst of the present invention include aliphatic chain carboxylic acids such as acetic acid, butyric acid, lauric acid, oleic acid, linoleic acid, linolenic acid, stearic acid, and palmitic acid, aliphatic cyclic carboxylic acids such as cyclohexane carboxylic acid, naphthenic acid, and cyclopentane carboxylic acid, aliphatic polycarboxylic acids such as oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, cyclohexane dicarboxylic acid, 1,2, 4-butane tricarboxylic acid, 1,3, 4-cyclohexane tricarboxylic acid, dicyclohexyldicarboxylic acid, and decalin dicarboxylic acid, and aromatic carboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, and trimesic acid.

The carboxylic acid is not particularly limited, but is preferably a chain or cyclic saturated aliphatic carboxylic acid, more preferably a carboxylic acid having 20 or less carbon atoms and containing no functional group other than a carboxyl group, and still more preferably a dicarboxylic acid having 20 or less carbon atoms and containing no functional group other than a carboxyl group and represented by the formula (2).

HOOC-R¹-COOH(2)

(Wherein R ¹ is an aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms other than the substituent, and optionally has a substituent)

Particularly preferred is an aliphatic or alicyclic polycarboxylic acid having 4 to 14 carbon atoms or an ester thereof, which has a high activity in the reduction reaction and a high selectivity, and thus is suitable.

In the present invention, 1, 4-cyclohexanedicarboxylic acid or an ester thereof is particularly preferably used as a reactant to produce the corresponding alcohol by a reduction reaction. That is, a method for producing an alcohol by contacting a raw material of 1, 4-cyclohexanedicarboxylic acid or 1, 4-cyclohexanedicarboxylic acid ester (diester) with the catalyst of the present invention and reducing the raw material is preferable.

In the case of using an ester of these carboxylic acids, examples of the alcohol component include lower alcohols such as methanol, ethanol, isopropanol, and n-butanol.

Further, the esterification may be performed with the same alcohol as that obtained by the reduction. In this case, there is an advantage in that it is not necessary to separate the alcohol generated in the subsequent hydrogenation reaction.

The reduction reaction using the catalyst of the present invention may be carried out in the absence of a solvent or in the presence of a solvent, and is usually carried out in the presence of a solvent.

As the solvent, there can be generally used solvents such as lower alcohols such as water, methanol and ethanol, alcohols as reaction products, ethers such as tetrahydrofuran, dioxane and ethylene glycol dimethyl ether, hydrocarbons such as hexane and decalin. These solvents may be used alone or in combination of two or more.

In particular, in the case of reducing carboxylic acid, a solvent containing water is preferably used for the reasons of solubility and the like.

The amount of the solvent to be used is not particularly limited, but is preferably about 0.1 to 20 mass times, preferably about 0.5 to 10 mass times, more preferably about 1 to 10 mass times, based on the carboxylic acid or carboxylic ester as the raw material.

The reduction reaction using the catalyst of the present invention is usually carried out under hydrogen pressure. The reaction is usually carried out at 100 to 300 ℃, preferably 150 to 300 ℃. The reaction pressure is 1 to 30MPa, preferably 1 to 25MPa, and more preferably 5 to 25MPa.

The reduction reaction using the catalyst of the present invention can be carried out in both liquid and gas phases, but it is preferable to carry out the reduction reaction in liquid phase because the reduction reaction is carried out while the carboxylic acid/carboxylic ester is gasified and the reduction reaction is carried out while maintaining the gaseous state, which makes the apparatus large and requires a large amount of energy.

In addition, the hydrogenation process of carboxylic acids and/or carboxylic acid esters by contacting the catalyst of the present application with carboxylic acids and/or carboxylic acid esters is also included within the scope of the present application.

Examples

The present invention will be described in further detail with reference to the following examples, but the present invention is not limited to the following examples unless the gist thereof is exceeded.

< Method for measuring TPR >

Catalyst (0.1 g) was charged into a fine quartz tube, 10% H ₂/He was flowed at 20ml/min, and the concentration of H ₂ was kept stable until the hydrogen substitution in the system ended. Thereafter, the temperature was raised to 700℃at a certain rate over 60 minutes. During this period, the amount of hydrogen absorbed was calculated by continuously measuring the amount of hydrogen at the outlet using a mass spectrometer. < method for confirming reactivity of catalyst >

The reactivity and selectivity of the catalyst obtained in the present invention were confirmed by using a reaction for producing 1, 4-Cyclohexanedimethanol (CHDM) based on a hydrogenation reaction of 1, 4-cyclohexanedicarboxylic acid (CHDA).

An induction stirring autoclave (hereinafter, sometimes referred to as "reactor") made of hastelloy C (registered trademark) was charged with 40g of water, 10g of CHDA (a mixture of cis and trans forms: manufactured by Tokyo chemical industry Co., ltd.) and 2g of a catalyst to be evaluated, and after hydrogen substitution in the reactor, the reaction was started at 240℃under stirring at 1000rpm with a hydrogen partial pressure of 1MPa (a stirring number that does not limit the hydrogen supply due to an excessively slow stirring number and does not cause cracking of the catalyst due to an excessively high stirring number), and the reactor was heated. Hydrogen was continuously supplied from a hydrogen accumulator into the reactor, and the reaction was carried out at 240 ℃ and 8.5MPa for 3 hours. After the completion of the reaction, the presence or absence of cracking of the catalyst was visually confirmed. At this time, the apparent reaction rate of the reaction in which the cracking of the catalyst occurs becomes high, and the selectivity cannot be accurately compared, and is therefore excluded.

The reaction solution obtained was subjected to neutralization titration with NaOH to determine the conversion of carboxyl groups, and analysis of the product was performed using a gas chromatograph. The main product is CHDM as a target, and the main byproducts are cyclohexane methanol (CHM) and 4-methylcyclohexane methanol (MCHM). In addition to the two byproducts described above, the CHDM was used in approximately the entire amount, so that the catalytic performance was compared by the conversion of carboxyl groups and the yield of byproducts.

Comparative example 1

A catalyst was prepared by the method of example 4 of Japanese patent application laid-open No. 2001-9277 using a cylindrical active carbon (R1 EXTRA manufactured by Cabot Norit Co., ltd.) carrier having a diameter of 1mm and a length of 2 to 5mm as a carrier. Specifically, ruthenium chloride hydrate (RuCl ₃·xH₂ O), hexachloroplatinic (IV) acid (hexahydrate, etc.) (H ₂PtCl₆·6H₂ O), and tin (II) chloride (SnCl ₂·2H₂ O) were dissolved in a dilute hydrochloric acid solution, and activated carbon treated with nitric acid was added thereto. And removing the solvent from the catalyst, drying, putting the dried catalyst into ammonium bicarbonate solution for treatment, and filtering, cleaning and drying to prepare the metal load. In the preparation of the metal support, 1.1ml of 0.3% dilute hydrochloric acid is used per 1g of activated carbon used, with respect to the dissolution water of the metal chloride. The amount of the metal chloride to be charged is such that when the oxidation stabilization is performed by hydrogen reduction in the entire amount of the charged amount, the metal content in the supported catalyst is such that Ru5.5 mass%, pt2.4 mass% and Sn6.4 mass% (hereinafter, the amount of the metal to be charged is all expressed as mass%). The ammonium bicarbonate used was in the form of an 11 mass% aqueous solution having a molar amount of 1.7 times that of chlorine in the metal chloride, and water at 90℃was used for washing.

The obtained metal support was reduced under a hydrogen stream at 500 ℃, and then subjected to oxidation stabilization under a diluted oxygen atmosphere to prepare a catalyst. Hereinafter, the catalyst is referred to as a "reduction catalyst".

The reaction is carried out with the catalyst. The conversion and the yield of by-products are shown in table 1.

In the columns of the metal species in table 1, the compounds used are shown for the metal species other than ruthenium, platinum, and tin.

Comparative example 2

Iron (III) acetylacetonate (Fe (acac) ₃) was supported on the reduction catalyst obtained in comparative example 1, and after reduction, the catalyst was prepared so that the Fe was supported at 0.1 mass%. Specifically, 0.86ml of tetrahydrofuran solvent was used for each 1g of the reduction catalyst, a predetermined amount of Fe (acac) ₃ was dissolved, about 10g of the reduction catalyst obtained in comparative example 1 was added, and the mixture was stirred and left for 1 hour. After that, the mixture was evaporated at 80℃for 1 hour under reduced pressure of 1kPa, and then placed in a glass tube, and dried at 150℃for 2 hours under a flow of argon of 5L/hour in an electric furnace.

The dried catalyst (2.5 g) was again placed in a glass tube, and placed in an electric furnace, and reduction treatment was performed at 500℃for 2 hours under a flow of hydrogen (5L/hr). Thereafter, the catalyst was cooled under argon flow and stabilized under 6 vol% oxygen/nitrogen flow at room temperature to obtain a 0.1% Fe-supported catalyst.

Using this catalyst (the amount of catalyst used: the amount of the reduction catalyst used for the preparation was 2 g), the same reaction as in comparative example 1 was carried out. The results are shown in Table 1.

Comparative example 3

An Fe-supported catalyst was obtained in the same manner as in example 1, except that iron (III) chloride hexahydrate (FeCl ₃·6H₂ O) was used instead of iron (III) acetylacetonate (Fe (acac) ₃) and water was used as a solvent in comparative example 2. Using this catalyst, the same reaction as in comparative example 1 was carried out. The results are shown in Table 1.

Comparative example 4

A 0.5% Fe supported catalyst was obtained in the same manner as in comparative example 2, except that Fe (acac) ₃ was used in the amount of 0.5 mass% of Fe metal in comparative example 2. Using this catalyst, the same reaction as in comparative example 1 was carried out. The results are shown in Table 1.

Comparative example 5

A 0.5% Fe supported catalyst was obtained in the same manner as in comparative example 3, except that 0.5 mass% of FeCl ₃·6H₂ O was used as Fe metal in comparative example 3. Using this catalyst, the same reaction as in comparative example 1 was carried out. The results are shown in Table 1.

Reference example 1

A 0.2 mass% Cr-supported catalyst was obtained in the same manner as in comparative example 3, except that chromium (III) chloride hexahydrate (CrCl ₃·6H₂ O) was used instead of iron (III) chloride hexahydrate (FeCl ₃·6H₂ O) in comparative example 3. Using this catalyst, the same reaction as in comparative example 1 was carried out. The results are shown in Table 1.

Reference example 2

A0.5% Cr-supported catalyst was obtained in the same manner as in comparative example 2, except that chromium (III) acetylacetonate (Cr (acac) ₃) was used in place of iron (III) acetylacetonate (Fe (acac) ₃) in comparative example 2. Using this catalyst, the same reaction as in comparative example 1 was carried out. The results are shown in Table 1.

Comparative example 6

The same reaction as in comparative example 1 was carried out using this catalyst, except that ammonium paramolybdate (ammonium molybdenum (VI) acid tetrahydrate ((NH ₄)₆Mo₇O₂₄·4H₂ O)) was used instead of iron (III) acetylacetonate (Fe (acac) ₃) and water was used as a solvent in comparative example 2, to obtain a 0.5% mo-supported catalyst in the same manner as in comparative example 2.

Comparative example 7

RuCl ₃·xH₂ O (Ru content 41.9％)1.131g、H₂PtCl₆·6H₂O 0.547g、SnCl₂·2H₂O 0.883g、FeCl₃·6H₂O 1.196g) was dissolved in a 0.3% hydrochloric acid solution, 7.41g of the activated carbon after nitric acid treatment as in comparative example 1 was added to the solution, and after sufficient stirring, the solution was left for 3 hours and dried by an evaporator, and then transferred to a firing tube, and dried under argon flow at 150 ℃ for 2 hours, the catalyst was added to an aqueous solution of 1.7 equivalent of ammonium bicarbonate with a total chlorine content of the metal chloride used, treated for 1 hour and filtered, washed with 90 ℃ water, and dried by an evaporator, the dried catalyst was transferred to a firing tube, additional drying was performed under argon flow at 150 ℃, 2.5g of the additional dried catalyst was reduced under hydrogen flow at 500 ℃, and after cooling, stabilization was performed with 6% oxygen/nitrogen, 5.5% Ru-2.4% Pt-5.4% Sn-0.47% Fe/activated carbon was prepared (calculated on the basis of the calculated values of the total chlorine content of the metal chloride used, and calculated as "the catalyst in Table 1" ₃ ", and the catalyst was used in comparative example 1 and table 1.48 g of the catalyst was prepared.

Example 1

A0.2% Fe-0.2% Cr-supported catalyst was obtained in the same manner as in comparative example 2 except that FeCl ₃·6H₂O、CrCl₃·6H₂ O was used in an amount of 0.2% Fe metal and 0.2% Cr metal in the reduction catalyst obtained in comparative example 1 and water was used as a solvent. Using this catalyst, the same reaction as in comparative example 1 was carried out. The results are shown in Table 1.

Example 2

A catalyst supported by 0.4% Fe-0.1% Cr was obtained in the same manner as in comparative example 2 except that FeCl ₃·6H₂O、CrCl₃·6H₂ O was used in an amount of 0.4% Fe metal and 0.1% Cr metal in the reduction catalyst obtained in comparative example 1 and water was used as a solvent. Using this catalyst, the same reaction as in comparative example 1 was carried out. The results are shown in Table 1.

Example 3

A catalyst supported on 0.2% Fe-0.2% Mo was obtained in the same manner as in comparative example 2 except that FeCl ₃·6H₂O、(NH₄)₆Mo₇O₂₄·4H₂ O was used in an amount of 0.2% Fe metal and 0.2% Mo metal in the reduction catalyst obtained in comparative example 1 and water was used as a solvent. Using this catalyst, the same reaction as in comparative example 1 was carried out. The results are shown in Table 1.

Example 4

The same reaction as in comparative example 1 was carried out using the reduced catalyst obtained in comparative example 1 with the exception that 0.4% of Fe metal and 0.1% of Mo metal were used as FeCl ₃·6H₂ O and ammonium molybdenum (VI) acid tetrahydrate ((NH ₄)₆Mo₇O₂₄·4H₂ O) and 3% aqueous HCl was used as a solvent, and a catalyst supported by 0.4% Fe-0.1% Mo was obtained in the same manner as in comparative example 2.

TABLE 1

As is clear from table 1, according to the catalyst of the present invention on which Fe and Cr are supported and the catalyst of the present invention on which Fe and Mo are supported, the yields of cyclohexane methanol (CHM) and 4-methylcyclohexane methanol (MCHM) as main by-products can be reduced while maintaining a high conversion rate. In contrast, it was found that comparative examples 2 to 5, in which only iron was supported, and comparative example 6, in which only molybdenum was supported, were inferior to the catalyst of the present invention, although some effects were confirmed when compared with the unmodified catalyst, which was not modified with iron or the like.

As described above, it is found that the catalyst of the present invention can maintain a high conversion rate, and the by-product yield is suppressed to 60% or less compared with the case where the catalyst is not added, and shows excellent effects.

Industrial applicability

According to the present invention, by adding a plurality of new specific metals to the conventional reduction catalyst combination, the by-product yield is extremely reduced and the target yield is improved. The present invention is industrially extremely useful technology because the yield of by-products is extremely reduced, and thus, in the case of using the by-products as a raw material for a polymer later, a precise purification step can be omitted or simplified.

Claims

1. A metal-supported catalyst for hydrogenation of carboxylic acids and/or carboxylic acid esters, wherein ruthenium, tin and platinum are supported on a carrier, and wherein iron, chromium and/or molybdenum are also supported on the metal-supported catalyst.

2. The metal-supported catalyst according to claim 1, wherein,

The iron loading is 0.01 mass% or more and 4 mass% or less relative to the total mass of the metal-supported catalyst, and the total loading of chromium and/or molybdenum is 0.01 mass% or more and 2 mass% or less.

3. The metal-supported catalyst according to claim 1 or 2, wherein,

The carrier is a carbonaceous carrier.

4. The metal-supported catalyst according to claim 1 or 2, wherein,

The total loading of ruthenium, tin, platinum, iron, molybdenum and chromium is 5 mass% or more relative to the total mass of the metal-supported catalyst.

5. The metal-supported catalyst according to claim 1 or 2, wherein,

The metal supported catalyst is prepared by hydrogen reduction.

6. A process for producing an alcohol, comprising bringing the metal-supported catalyst according to claim 1 or 2 into contact with a carboxylic acid and/or a carboxylic acid ester and reducing the carboxylic acid and/or the carboxylic acid ester to obtain an alcohol corresponding to each of the carboxylic acid and/or the carboxylic acid ester.

7. A process for the hydrogenation of carboxylic acids and/or carboxylic acid esters by contacting the metal supported catalyst of claim 1 or 2 with carboxylic acids and/or carboxylic acid esters.

8. The method for producing an alcohol according to claim 6, wherein,

The carboxylic acid is 1, 4-cyclohexanedicarboxylic acid and the carboxylic acid ester is 1, 4-cyclohexanedicarboxylic acid ester.