WO2024024750A1 - Metal-loaded catalyst, method for producing alcohol and hydrogenation method - Google Patents

Abstract

The present invention provides a metal-loaded catalyst which is obtained by loading a carrier with ruthenium, tin and platinum, and which is used for hydrogenation of a carboxylic acid and/or a carboxylic acid ester; and this metal-loaded catalyst is additionally loaded with iron and chromium and/or molybdenum.　The present invention also provides: a catalyst which has a further lower by-product yield, while maintaining a high catalytic activity; a method for producing an alcohol from a carboxylic acid and/or a carboxylic acid ester with use of this catalyst; and a hydrogenation method for a carboxylic acid and/or a carboxylic acid ester.

Description

Metal-supported catalyst, alcohol production method and hydrogenation method

The present invention relates to a supported metal catalyst, and specifically relates to a supported metal catalyst that can hydrogenate carboxylic acids and/or carboxylic esters with high selectivity, a method for producing alcohol using the supported metal catalyst, and a method for hydrogenation.

As catalysts for reducing carboxylic acids and/or carboxylic acid esters to the corresponding alcohols, catalysts have been proposed in which ruthenium, tin, and platinum are supported on a carrier and this is reduced with hydrogen or the like (for example, a patent References 1, 2). This catalyst exhibits high reaction activity and reaction selectivity in the hydrogenation of carboxylic acids and/or carboxylic acid esters, and is a good catalyst.
Further, Patent Document 3 discloses a catalyst in which iron is further supported on a reduction catalyst. More specifically, a supported catalyst is disclosed 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, and 1,4-cyclohexanedimethanol is produced. is disclosed.

Japanese Patent Application Publication No. 2001-9277 International Publication No. 2015/178459 Chinese Patent No. 104722321

When the hydrogenation reaction of carboxylic acid and/or carboxylic acid ester is carried out using the conventionally known catalysts described in Patent Documents 1 and 2, although the hydrogenation activity is high, C-C bonds and C-O bonds By-products are generated due to the cleavage of the target product, which lowers the yield of the desired product and requires precise operations to remove the by-products.
Although the catalyst disclosed in Patent Document 3 suppresses the production of by-products compared to the catalysts described in Patent Documents 1 and 2, the degree of this is insufficient, and further improvement has been desired. .
In view of the above-mentioned circumstances, the present invention aims to provide a catalyst that maintains high catalytic activity and has a lower yield of by-products.

The present inventors have discovered that a metal-supported catalyst in which ruthenium, tin, and platinum are supported on a carrier, and in which iron, chromium, and/or molybdenum are further supported, maintains high catalytic activity. , it was found that the yield of by-products could be significantly reduced.
Although the details are not clear, iron, chromium, and molybdenum have the effect of selectively suppressing active sites that cleave C-C bonds and C-O bonds, rather than active sites that reduce carbonyls on the catalyst. It has been found that the above effects can be particularly exhibited by a combination of iron and chromium, a combination of iron and molybdenum, and a combination of the three components of iron, chromium, and molybdenum.

The gist of the invention is as follows.
[1] A metal-supported catalyst used for the hydrogenation of carboxylic acids and/or carboxylic acid esters, in which ruthenium, tin, and platinum are supported on a carrier, wherein the metal-supported catalyst further supports iron, chromium, and/or A metal-supported catalyst that supports molybdenum.
[2] The amount of iron supported is 0.01% by mass or more and 4% by mass or less with respect to the total mass of the metal supported catalyst, and the total amount of chromium and/or molybdenum supported is 0.01% by mass or more and 2% by mass. % or less, the metal-supported catalyst according to [1] above.
[3] The metal-supported catalyst according to [1] or [2] above, wherein the carrier is a carbonaceous carrier.
[4] The supported metal according to any one of [1] to [3] above, wherein the total supported amount of ruthenium, tin, platinum, iron, molybdenum, and chromium based on the total mass of the metal supported catalyst is 5% by mass or more. catalyst.
[5] The metal-supported catalyst according to any one of [1] to [4] above, wherein the metal-supported catalyst is prepared through hydrogen reduction.
[6] A carboxylic acid and/or a carboxylic ester is brought into contact with the metal-supported catalyst according to any one of [1] to [5] above to reduce the carboxylic acid and/or the carboxylic ester, respectively. A method for producing alcohol, obtaining the corresponding alcohol.
[7] A method for hydrogenating carboxylic acids and/or carboxylic esters, which comprises contacting the carboxylic acids and/or carboxylic esters with the metal-supported catalyst according to any one of [1] to [5] above.
[8] The method for producing alcohol according to [6] above, wherein the carboxylic acid is 1,4-cyclohexanedicarboxylic acid, and the carboxylic acid ester is an ester of 1,4-cyclohexanedicarboxylic acid.

According to the present invention, a catalyst with a lower by-product yield while maintaining high catalytic activity, a method for producing alcohol from a carboxylic acid and/or a carboxylic acid ester using the catalyst, and a method for producing alcohol from a carboxylic acid and/or a carboxylic acid ester, and A method for hydrogenating acids and/or carboxylic esters can be provided.

The embodiments of the present invention will be described in detail below, but the explanation of the constituent elements described below is an example (representative example) of the embodiments of the present invention, and the present invention is limited to these contents. Rather, it can be implemented with various modifications within the scope of the gist.
In this application, the metals (ruthenium, tin, platinum, and other metals such as iron used as necessary) supported on a carrier may be collectively referred to as "metal components." Further, catalysts in which the metal component is supported on a carrier, catalysts subjected to reduction treatment, and catalysts subjected to oxidation stabilization treatment are collectively referred to as "metal-supported catalysts." Furthermore, a "metal-supported catalyst" that has been subjected to such oxidation stabilization treatment and further supports a metal component is also referred to as a "metal-supported catalyst." In addition, in the metal-supported catalyst, the catalyst at a stage before reduction treatment is sometimes referred to as a "metal-supported material".

[Metal supported catalyst]
The metal-supported catalyst of the present invention (hereinafter sometimes simply referred to as "the present catalyst") is obtained by reducing a metal-supported material in which the metal component is supported on a carrier, usually with a reducing gas. . Moreover, those obtained by oxidizing the reduced metal supported catalyst are also included in the metal supported catalyst of the present invention. Metal-supported catalysts also include catalysts to which a metal component is added after these treatments.

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 further contains iron, chromium, and/or platinum. Or it is supported by molybdenum. Specifically, there are embodiments of combinations of iron and chromium, combinations of iron and molybdenum, and combinations of the three components of iron, chromium, and molybdenum. By using a metal-supported catalyst having such a configuration, the yield of by-products accompanied by the cleavage of C--C bonds and C--O bonds can be further suppressed while maintaining the hydrogenation activity.
For example, when 1,4-cyclohexanedicarboxylic acid is hydrogenated as a carboxylic acid, cyclohexanemethanol with C-C cleavage and 4-methylcyclohexanemethanol with C-O cleavage are produced together with the target product 1,4-cyclohexanedimethanol. It is produced as a by-product, and the yield of the target product decreases. On the other hand, by using the catalyst of the present invention, the generation 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 polyester and polyurethane, but in that case, monoalcohols such as cyclohexanemethanol and 4-methylcyclohexanemethanol are used as polymerization terminators. Therefore, contamination must be avoided during resin synthesis, and removal operations are required. On the other hand, when the amount of by-products produced in the hydrogenation reaction is reduced, there is an advantage that the purification operation for removing monoalcohol can be simplified or skipped.

<Carrier>
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, such as carbonaceous carriers such as activated carbon and carbon black; alumina, silica, diatomaceous earth, zirconia, titania, Inorganic porous carriers such as hafnia; silicon carbide, gallium nitride, etc. are used. Among these, carbonaceous supports such as activated carbon, graphite, and graphite, titania, and zirconia are preferable, and carbonaceous supports are more preferable because they have excellent stability and are easy to obtain industrially, and have a high surface area and excellent metal dispersibility. Activated carbon is more preferably used since it is easy to increase the reaction activity. Note that one type of carrier may be used or two or more types may be used in combination.

The carrier may be used as it is or may be pretreated into a form suitable for supporting. For example, if a carbonaceous carrier is used, the carbonaceous carrier can be heat-treated with nitric acid before use, as described in JP-A-10-71332. By the method described above, the dispersibility of the metal component on the carrier can be improved, and the activity of the resulting catalyst can be improved.
The shape and size of the carrier used in the present invention are not particularly limited, but when the shape is converted into a sphere, the average primary particle diameter is usually 50 μm or more and 5 mm or less, preferably 4 mm or less. It is. Note that the particle size is measured by the sieving test method described in the JIS standard JIS Z8815.

Since the suitable particle size of the carrier varies depending on the reaction using the present catalyst, it is preferable to adjust it depending on the reaction. Specifically, when the reaction using the present catalyst is a completely mixed reaction, the particle size of the carrier is usually 50 μm or more, preferably 100 μm or more, and usually 3 mm or less, preferably 2 mm or less. The smaller the particle size of the carrier, the higher the activity per unit mass of the obtained catalyst, which is preferable, but if the particle size is too small, it may become difficult to separate the reaction liquid and the catalyst. That is, it is preferable in terms of reaction activity that the particle diameter of the carrier is at least the above-mentioned lower limit, and it is preferable that it is below the above-mentioned upper limit because separation from the reaction liquid is easy.
Note that when the shape of the carrier is not spherical, the volume of the carrier is determined and converted to the diameter of a spherical particle having the same volume.

Furthermore, when the reaction using the present catalyst is a fixed bed reaction, the particle size of the carrier is usually 0.5 mm or more and 5 mm or less, preferably 4 mm or less, and more preferably 3 mm or less. When it is above the lower limit, operation will not become difficult due to differential pressure, and when it is below the upper limit, sufficient reaction activity can be obtained.

<Metal component>
The metal-supported catalyst of the present invention is a catalyst in which ruthenium, tin, and platinum are supported as essential elements on a carrier, and the catalyst further includes iron, chromium, and/or molybdenum (hereinafter referred to as "other metals such as iron"). It is a metal-supported catalyst formed by supporting a metal. By additionally supporting iron, chromium and/or molybdenum, the generation of by-products can be further suppressed. A higher effect of suppressing the production of by-products can be obtained by supporting iron, chromium and/or molybdenum.
Furthermore, in addition to ruthenium, tin, platinum, iron, chromium, and molybdenum, other metals may be included as necessary, and preferably, as long as they do not adversely affect reactions such as reduction reactions using this catalyst. It can contain at least one metal selected from metal species such as rhodium, tungsten, rhenium, barium, and boron, and more preferably contains rhenium.
Note that the raw materials for each metal component will be described later.

(Amount of metal component supported)
The amount of metal component supported in the present catalyst is not particularly limited, and is determined for each metal. The amount of ruthenium supported is usually 1% by mass or more, preferably 3% by mass or more, and usually 10% by mass or less, preferably 8% by mass or less, as a mass ratio to the total mass of the metal-supported catalyst. Similarly, the amount of tin supported is usually 1% by mass or more, preferably 2% by mass or more, and usually 15% by mass or less, preferably 10% by mass or less, as a mass ratio to the total mass of the metal-supported catalyst. Similarly, the amount of platinum supported is usually 0.5% by mass or more, usually 7% by mass or less, and preferably 5% by mass or less, as a mass ratio to the total mass of the metal-supported catalyst. Setting the content within these ranges is preferable because the ability as a hydrogenation catalyst increases. The supported amounts of iron, chromium and/or molybdenum are each preferably 0.01% by mass or more and 4% by mass or less, more preferably 2% by mass or less. By setting it within this range, the generation of by-products can be significantly reduced. That is, the supported amount of iron is preferably 0.01% by mass or more and 4% by mass or less, and more preferably 0.01% by mass or more and 2% by mass or less. When either one of chromium and/or molybdenum is supported, the preferred range of supported amount of each metal is 0.01% by mass or more and 4% by mass or less, and more preferably 0.01% by mass or less. It is at least 2% by mass and not more than 2% by mass. When both chromium and molybdenum are supported, the total amount of both supported is preferably within the above range. In addition, in order to sufficiently obtain the effect of suppressing by-products by using iron and chromium in combination, the composition ratio is not particularly limited as long as it is within the above-mentioned range, but for example, 100:1 to 1:100 is used, and more preferably The ratio is 10:1 to 1:10, more preferably 10:1 to 1:5. The same range is also preferred when iron and molybdenum are used together. On the other hand, in terms of cost, chromium and molybdenum are more expensive than iron, so in this sense it is preferable to use less than iron.

The total supported amount of other metals such as ruthenium, tin, platinum, and iron based on the total mass of the metal-supported catalyst is not particularly limited, but is usually 5% by mass or more, preferably 8% by mass or more, and more preferably 10% by mass. The above amount is usually 40% by mass or less, preferably 30% by mass or less, and more preferably 20% by mass or less.
Note that the amount of supported metal is a value calculated assuming that all supported metals are metal atoms. Further, the size of the metal-supported catalyst after reduction of the present invention is not particularly limited, but is basically the same as the size of the support described above.
Note that the amount of supported metal (hereinafter sometimes referred to as "metal") can be measured, for example, by the following method. The catalyst can be powdered and stirred to a uniform state, and if necessary, formed into a disk and analyzed in its solid state by fluorescent X-ray analysis. Alternatively, it can be made into a homogeneous solution after alkali melt decomposition or pressure decomposition using microwaves, and then analyzed by ICP emission spectroscopy (high-frequency inductively coupled plasma emission spectroscopy).
Among these, ICP optical emission spectrometry (high frequency inductively coupled plasma optical emission spectrometry) is preferred, since more accurate measurement results can be obtained by forming a homogeneous solution.

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

<<Metal support process>>
The metal supporting step is a step in which the above-described metal component is supported on the above-described carrier to obtain a metal-supported material. The method of supporting the metal component is not particularly limited, and any known method can be used. For supporting, solutions or dispersions of various metal compounds that serve as raw materials for the metal components can be used.

(Metal support method)
The method of supporting the metal component on the carrier is not particularly limited, but various impregnation methods are usually applicable. For example, an adsorption method that utilizes the adsorption power of metal ions to a carrier to adsorb metal ions below the saturated adsorption amount, an equilibrium adsorption method that immerses the carrier in a solution of metal ions that exceeds the saturated adsorption amount and removes the excess solution; The pore-filling method involves adding a solution of metal ions in an amount equal to the pore volume of the carrier and adsorbing all of the metal ions to the carrier.The pore-filling method involves adding a solution of metal ions in an amount equal to the pore volume of the carrier, and adding a solution of metal ions to match the amount of water absorbed by the carrier. There are the incipient wetness method, which completes the process in the absence of a solution, the evaporation dryness method, which impregnates a carrier with a solution of metal ions and evaporates the solvent while stirring, and the spraying method, which sprays the solution onto the carrier while it is in a dry state.
Among the above methods, the pore filling method, the incipient wetness method, the evaporation to dryness method, and the spraying method are preferred, and the pore filling method, the incipient wetness method, and the evaporation to dryness method are more preferred. By the method described above, ruthenium, tin, platinum, and other metal components such as iron can be supported in a relatively uniformly dispersed state.

For supporting, all the metal solutions to be supported may be prepared and then supported at once, or each metal may be supported separately. Further, in the case of carrying the metal separately, it may be carried separately for each type, or it may be carried separately by a plurality of metal solutions. From the viewpoint of shortening the supporting process, it is preferable to support the entire metal solution at once or to support the metals in divided manner. The timing of split-supporting is not particularly limited, and multiple types of metals may be simply supported in several steps, or after the process up to hydrogen reduction is carried out, split-supporting may be carried out, or hydrogen It may be supported in parts on the metal-supported catalyst after reduction.

(metal compound)
The metal compound used for supporting is not particularly limited, and can be appropriately selected depending on the supporting method. For example, halides such as chlorides, bromides, and iodides; mineral acid salts such as nitrates and sulfates; organic acid salts such as acetates; metal hydroxides, metal oxides, organometallic compounds, metal complexes, etc. Can be done. Among these, halides, mineral acid salts, organic acid salts, etc. are preferable, halides and mineral acid salts are more preferable, it is even more preferable to use halides, and among the halides, chlorides such as hydrochloride are particularly preferable. . Further, it is preferable that at least one kind of the above-mentioned metal compound is a chloride, and it is more preferable that all of them are chlorides. It is thought that by using a chloride, the metals are complexed in a solution state, and the dispersion state of each metal on the supported carrier becomes uniform, so that the metals are stably supported. In addition, the growth of alloy particles due to other metal components such as ruthenium, tin, platinum, and iron in the resulting catalyst is suppressed, and the activity and selectivity are improved, as well as the stability of the catalyst during the reaction.

More specifically, examples of ruthenium include ruthenium chloride, ruthenium nitrosyl nitrate, tris(acetylacetonate)ruthenium, and the like. These ruthenium salts may be used alone or in combination of two or more.
In the case of tin, specific examples include tin compounds such as tin (II) chloride, tin (IV) chloride, tin (II) acetate, tin (IV) acetate, dibutyltin dilaurate, dibutyltin oxide, and dibutyltin dimethoxide. . One type of tin compound may be used alone, or two or more types may be used in combination.
In the case of platinum, a platinum precursor compound is used, and platinum precursor compounds include hexachloroplatinic (IV) acid (hexahydrate, etc.), potassium tetrachloroplatinate (II), hexachloroplatinic (IV) acid. Potassium, potassium tetracyanoplatinate(II), sodium hexachloroplatinate(IV) (hexahydrate), hydrogen hexahydroxyplatinate(IV), potassium tetracyanoplatinate(II) (hydrate), hexachloroplatinate ( IV) Tetrabutylammonium and the like. One type of platinum precursor compound may be used alone, or two or more types may be used in combination.

As other metal compounds such as iron, specifically, iron salts, chromium compounds, and molybdenum compounds illustrated below can be used.
As the iron salt, it is preferable to use one selected from the group consisting of iron chloride, iron nitrate, iron sulfate and iron acetylacetonate.
Examples of chromium compounds include 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 types known to be used in the production of chromium oxide catalysts. can be used.
As the molybdenum compound, a molybdenum compound containing a molybdenum element in an oxidized state is preferable, and examples thereof include molybdenum trioxide, molybdic acid, molybdate salts, and heteropolyacids. Among these, molybdenum trioxide and molybdate are more preferred. Examples of molybdates include ammonium paramolybdate, ammonium dimolybdate, and ammonium tetramolybdate. One type of molybdenum raw material may be used, or two or more types may be used in combination.

(solvent)
When supporting the metal compound on a carrier, the metal compound can be dissolved or dispersed using various solvents and used in various supporting methods. The type of solvent used at this time is not particularly limited as long as it can dissolve or disperse the metal compound and does not adversely affect the subsequent calcination and hydrogen reduction of the metal support, as well as the hydrogenation reaction using the present catalyst. Examples 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 invention, as described above, a halide, more preferably a chloride is used as the metal compound, and since these halides have high solubility, water is preferably used.
Moreover, when dissolving or dispersing the metal compound, various additives may be added in addition to the solvent. For example, as described in JP-A-10-15388, by adding a carboxylic acid and/or carbonyl compound solution, the dispersibility of each metal component on the carrier can be improved when supported on the carrier. Can be done.

<Metal support>
The metal-supported material in which the metal component is supported on a carrier can be used after being dried, if necessary, and preferably used after being dried. If the metal support is subjected to the subsequent reduction treatment without drying, the reaction activity may be lowered, and especially when the dehalogenation treatment described below is subsequently performed, the metal support is Drying is preferable in that it can suppress salt elution.
The drying method is not particularly limited as long as it removes the solvent used during support. Usually, it is carried out in the presence or flow of an inert gas.
The pressure for drying is not particularly limited, but it is usually carried out under normal pressure or reduced pressure conditions.
The drying temperature is not particularly limited, but is usually 300°C or lower, preferably 250°C or lower, more preferably 200°C or lower, and usually 80°C or higher.

<Dehalogenation treatment and cleaning>
The metal support can be subjected to a dehalogenation treatment, if necessary, before the reduction step described below. Particularly when a halide such as a chloride is used as a raw material for a metal component during the metal supporting step described above, a halogen compound may be generated in the reduction apparatus in the reduction step described below. This is not a problem at laboratory-scale throughput, but when reducing industrially in large quantities, a large amount of halogen compounds are generated in the reduction equipment, which may require exhaust gas treatment and may cause problems with the equipment. Corrosion may occur. Therefore, it is preferable to carry out dehalogenation treatment before carrying out the reduction step.
The method for dehalogenation treatment is not particularly limited, but usually the metal support is brought into contact with an alkaline compound in the gas phase or liquid phase to react with the halide in the metal support, followed by gas phase treatment. Or it can be removed by washing. Among these, from the viewpoint of ease of operation and high efficiency of removing halides from the metal support, it is preferable to treat the halides by bringing them into contact with an alkaline compound in a liquid phase, and then remove them by washing. Specifically, it is more preferable to wash with water after contacting with an alkaline aqueous solution.

The dehalogenation treatment temperature is not particularly limited, but is usually carried out at 10°C or higher, preferably 20°C or higher, and usually 150°C or lower, preferably 100°C or lower, more preferably 80°C or lower. When it is above the lower limit, dehalogenation treatment can be performed efficiently, and when it is below the upper limit, volatilization, thermal decomposition, etc. of the solvent and the alkali compound used in the treatment do not occur.

When using an alkaline aqueous solution for dehalogenation treatment, the pH of the alkaline aqueous solution is not particularly limited, but is usually 7.5 or higher, preferably 8.0 or higher, and usually 13.0 or lower, preferably 12.5 or lower. It is. When the pH is below the upper limit, there is no risk of deterioration of the supported metal due to too high pH, and elution of the supported metal is less likely to occur during the cleaning process described below. Further, when the amount is equal to or higher than the lower limit, sufficient dehalogenation is carried out.

As the type of alkali compound, for example, alkali metal carbonate, bicarbonate, ammonia, ammonium carbonate, ammonium bicarbonate, etc. can be used. These may be used alone or in combination of two or more. Among these, weakly basic alkaline compounds are preferred. The use of a weakly basic alkali compound such as ammonia or ammonium salt tends to yield a catalyst with higher activity than the use of a strongly basic alkali compound.

The amount of the alkali compound used is usually 0.1 to 50 equivalents, preferably 1 to 20 equivalents, and more preferably 1 to 10 equivalents relative to the halogen ions contained in the carrier. The alkaline compound is usually used as an aqueous solution, but a water-soluble solvent such as methanol, ethanol, acetone, or even ethylene glycol dimethyl ether, or a mixed solvent of these and water may also be used. It is preferable to use the alkaline aqueous solution in an amount that completely fills the pores of the carrier supporting the metal component of the metal support, that is, an amount equal to or greater than the pore capacity of the carrier. The amount of the alkaline aqueous solution to be used is not particularly limited as it depends on the concentration of the alkaline aqueous solution, but is usually 0.8 times or more and 20 times or less, preferably 1 time, the pore volume of the metal carrier used. It is not less than 1 times and not more than 10 times, more preferably not less than 1 time and not more than 5 times.

It is preferable to wash and remove excess alkali compounds and generated halides from the metal support that has been treated with an alkali compound. For cleaning, any solution that dissolves excess alkaline compounds and generated halides can be used, but water is preferred among these. In that case, the washing temperature is not particularly limited, and is usually carried out at a temperature of 10°C or higher and 100°C or lower, but is preferably 40°C or higher, more preferably 50°C or higher, since cleaning efficiency with hot water is good.
After the alkali treatment or the washing, drying may be further performed if necessary. As the drying conditions, the same conditions as those for drying the metal-supported material described above are used.

<Reduction treatment and reducing gas>
It is preferable that the metal support is subjected to a reduction treatment using a reducing gas to form a metal support catalyst. The reducing gas in the present invention is not particularly limited as long as it has reducing properties; for example, hydrogen, methanol, hydrazine, etc. are used, and hydrogen is preferred. That is, the metal-supported catalyst of the present invention is preferably prepared through hydrogen reduction.
In addition, in the reduction treatment in the present invention, a reduction reaction occurs regardless of the type of reducing gas, resulting in a metal-supported catalyst. The amount of reducing gas required for reduction treatment is expressed as "hydrogen absorption amount."
In the present invention, although not particularly limited, the reduction treatment of the metal support may be carried out in one stage or may be carried out in multiple stages.

(Reduction treatment temperature)
When manufacturing the metal-supported catalyst of the present invention, it is preferable to control the treatment temperature range and carry out the reduction treatment.
The reduction treatment temperature is not particularly limited, and may be a constant temperature or may be varied. The temperature is usually 80°C or higher, preferably 100°C or higher, more preferably 150°C or higher, and usually 650°C or lower, preferably 600°C or lower, and more preferably 580°C or lower. When the temperature is below the upper limit, there is no sintering of the metal component and no adverse effect on the carrier, while when it is above the lower limit, the reduction reaction proceeds sufficiently.
Specifically, the reduction treatment may be performed while maintaining a specific temperature within a preferred temperature range for a certain period of time, or may be performed while increasing the temperature within a preferred temperature range for a certain period of time. From the viewpoint of increasing the efficiency of the reaction time, it is preferable to perform the reduction treatment while increasing the temperature over a certain period of time, since the metal support generates heat and the temperature of the reaction system increases due to the reduction treatment. On the other hand, if severe heat generation is involved, it is preferable to maintain the temperature at a constant temperature so that the reaction can be accurately controlled.

(reducing gas concentration)
The concentration of the reducing gas during the reduction treatment of the present catalyst is not particularly limited, but may be 100% by volume or diluted with an inert gas. The inert gas mentioned here is a gas that does not react with the metal support or the reducing gas, and includes nitrogen, water vapor, etc., and nitrogen is usually used. The concentration of the reducing gas when diluted with an inert gas is usually 5% by volume or more, preferably 15% by volume or more, more preferably 30% by volume or more, and even more preferably 50% by volume, based on the total gas components. % or more. Alternatively, reduction treatment may be performed by using a low concentration of reducing gas at the initial stage of 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 know in advance the amount of hydrogen absorbed by the catalyst during reduction. The method for measuring the amount of hydrogen absorbed is not particularly limited, but the usual method is to perform reduction while adjusting the amount of hydrogen supplied per unit time and the heating time per unit time, that is, the Temperature Programmed Reduction method (hereinafter referred to as TPR). It is preferable to do so using the law. By using this method, the hydrogen absorption amount and absorption temperature of the present catalyst can be precisely measured.
In the TPR method, a catalyst to be measured is placed in a container, the temperature of the container is raised while a constant flow of hydrogen is supplied, and the amount of hydrogen at the inlet and outlet of the container is continuously measured. By such a method, it is possible to grasp the amount of hydrogen absorbed during reduction of the metal-supported catalyst. Specifically, it can be measured by the method described in Examples.

During the reduction treatment of the present catalyst, the reducing gas may be used while being sealed in the reactor or may be used while being circulated through the reactor, but it is preferable that the reducing gas is circulated through the reactor. Water, ammonium chloride, etc. are produced as by-products in the reactor during the reduction process, and these by-products may have an adverse effect on the metal support before the reduction process, the metal support after the reduction process, and the obtained catalyst. Yes, this can be prevented. That is, by circulating the reducing gas, byproducts can be discharged out of the reaction system.

The amount of reducing gas required for the reduction treatment is not particularly limited as long as the purpose of the present invention is achieved, and it depends on the reduction equipment, the size of the reactor during reduction, and the flow conditions. , can be set as appropriate. Normally, the amount of hydrogen required for each reduction treatment is 1.5 times or more, preferably 2 times or more, under conditions of high contact efficiency such that hydrogen flows through the catalyst layer, relative to the amount of hydrogen absorbed as determined by the TPR method. The flow rate is set to be at least twice as high, more preferably at least 3 times, particularly preferably at least 5 times. When the amount is at least the lower limit, reduction is sufficiently carried out especially when the contact efficiency with hydrogen is sufficient. There is no particular upper limit, but from the viewpoints of no problem with exhaust gas treatment, no scattering of metal supports or manufactured catalysts by reducing gases, and furthermore, avoidance of waste of excess reducing gases, It is usually 500 times or less, preferably 200 times or less.

(Reduction processing time)
The time required for the reduction treatment varies depending on the amount of metal support to be treated and the equipment used, but is usually 7 minutes or more, preferably 15 minutes or more, more preferably 30 minutes or more, and even more preferably 1 hour. The time period is 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 support catalyst after the reduction treatment described below. The halogen concentration in the metal supported catalyst is not particularly limited, but is usually 0.8% by mass or less, more preferably 0.7% by mass or less, still more preferably 0.5% by mass or less. It is preferable that the halogen concentration is lower because elution of the halogen into the reaction solution can be suppressed during the reduction reaction using the present catalyst. The lower limit of the halogen concentration is not particularly limited, but is usually 0.005% by mass or more, preferably 0.01% by mass or more. When the halogen concentration is within the above range, the metal support is sufficiently reduced, the elution of halogen into the reaction solution is suppressed to a low level, and the activity of the reduction reaction using the present catalyst is improved. Reaction selectivity is also improved, and catalyst stability is also improved.

<Aspects of preferred manufacturing method>
As mentioned above, the method for producing the catalyst of the present invention includes a metal supporting step, a dehalogenation step, a washing step, and a reduction step. In a preferred embodiment of the production method, a reducing gas is removed in a fixed bed in the reduction step. There are a method of passing the reducing gas through a catalyst, a method of passing the reducing gas through a catalyst placed on a tray or a belt, and a method of passing the reducing gas through the fluidized catalyst. Among these, it is preferable to carry out the reduction treatment while fluidizing the metal support in the reduction treatment. By performing the reduction treatment while flowing, the surface area in which the metal support and the reducing gas come into contact during the reduction treatment increases, so that the efficiency of the reduction treatment is improved.

The specific method of fluidizing is not particularly limited, as long as the metal support to be reduced undergoes a movement that increases the contact surface area with the reducing gas, for example, the metal to be reduced There are methods such as rotating a reactor containing a supported material, and methods of incorporating an apparatus configuration in which the metal supported material in the reactor is stirred or moved up and down.
Specific flow methods include methods using various types of kilns (heating furnaces).
Specifically preferred manufacturing methods include, for example, modes using a continuous kiln or a batch kiln.

(continuous kiln)
A continuous kiln is one that can continuously supply a metal support to carry out reduction and continuously discharge the reduced catalyst. Specifically, there are continuous rotary kilns, roller hearth kilns, belt kilns, tunnel kilns, etc. Among them, the production method of the present invention has high fluidity of the metal support and high contact efficiency with the reducing gas. Therefore, a continuous rotary kiln is preferred.

The operating conditions of the continuous kiln are not particularly limited as long as they satisfy the conditions for the reduction treatment described above, and can be set as appropriate depending on the equipment used. Normally, if a continuous kiln is used, it can be operated to satisfy the above-mentioned reduction processing conditions by controlling the flow rate and temperature of the reducing gas.
Since a continuous kiln can continuously supply a metal support and a reducing gas, it is possible to control the method of supplying a metal support into the continuous kiln and the flow rate of the reducing gas.

The flow rate of the reducing gas in the continuous kiln is not particularly limited, but the amount of hydrogen required for reduction, which is calculated by TPR measurement of the metal support, is the "hydrogen absorption amount A (m ³ / kg)", and the flow rate of the reducing gas in the continuous kiln is When the amount of metal support introduced into the kiln is B (kg/h), the hydrogen flow rate is usually at least (1.5×A×B) m ³ /h, preferably (2× A×B) m ³ /h or more, more preferably (5×A×B) m ³ /h or more. When the hydrogen flow rate is at least the lower limit, a sufficient amount of hydrogen is absorbed by the catalyst, and the performance of the resulting catalyst is maintained at a high level. The upper limit is not particularly limited, but in order to reduce the amount of wasted hydrogen, it is less than (1000 x A x B) m ³ /h, preferably less than (500 x A x B) m ^{3 /h, more preferably less than (500 x A x B) m 3} /h. (300×A×B) m ³ /h or less.

The flow direction of the metal support to be subjected to reduction treatment in a continuous kiln and the flow direction of reducing gas such as hydrogen can be adjusted as appropriate depending on the situation of the reduction treatment. It can be carried out either in co-current or counter-current to the flow direction. Above all, the catalyst that has reached the outlet of the continuous kiln can come into contact with high-purity hydrogen, and the flow direction of hydrogen is countercurrent to the flow direction of the metal support (they are opposite to each other). preferable.

The rotational speed of the continuous rotary kiln is not particularly limited. The higher the rotation speed, the better the contact efficiency between the metal support and hydrogen, but since the catalyst wears out, the rotation speed is usually 0.5 rpm or more and 10 rpm or less, preferably 5 rpm or less.

(Batch type kiln)
A batch type kiln is one in which a predetermined amount of metal support is charged into the kiln in advance, and the temperature is gradually raised to the desired reduction temperature under the flow of reducing gas, allowing reduction to be carried out at a predetermined temperature. Specifically, it refers to fixed-bed heating furnaces that are filled with metal supports for processing, tray-type heating furnaces that are heated on shelves, shuttle kilns in which a firing cart moves in and out of the electric furnace, and batch-type rotary kilns. etc.
Considering the efficiency of contacting the metal support with the reducing gas, a fixed bed heating furnace or a batch rotary kiln, in which the metal support is filled and processed, is preferable, and in order to achieve uniform reduction, it has a device for fluidizing the catalyst. Preferably, a batch rotary kiln is used.
Continuous kilns usually operate at a constant flow rate when introducing reducing gas due to equipment constraints, whereas batch kilns have a reaction tank for each batch, so there is no need to raise the temperature. , the flow rate, concentration, etc. of the reducing gas can be changed for each batch.

(Operating conditions for batch kiln)
The operating conditions of the batch kiln are not particularly limited, and can be set as appropriate depending on the configuration of the apparatus.
The batch-type rotary kiln that is preferably used in the present invention starts raising the temperature after charging a predetermined amount of metal support in advance, so the heating time to the final reduction temperature can be controlled more precisely than the continuous rotary kiln. It is possible to do so.
The time for the reduction treatment is not particularly limited, but is usually 1 hour or more, preferably 2 hours or more, and usually 40 hours or less, preferably 30 hours or less, and more preferably 10 hours or less. If it is too short than the above lower limit, if rapid hydrogen absorption occurs, a large amount of metal support is reduced at once, so intense heat generation and enormous hydrogen absorption occur, causing sintering of the catalyst and progressing. , stable operation may become difficult. Moreover, when it is more than the said lower limit, reduction time will be ensured, reduction will be sufficient, and sufficient reaction activity and selectivity as a catalyst will be obtained.
On the other hand, when the reduction treatment time is below the above-mentioned upper limit, the productivity of the catalyst can be ensured and there is no loss of hydrogen, which is industrially advantageous.

When a batch type rotary kiln is used, the concentration, flow rate, etc. of the reducing gas can be appropriately changed for each batch depending on the situation of the reduction process.
The preferred reducing gas concentration in the operation of a batch rotary kiln is the same as described above.

The flow rate of the reducing gas is not particularly limited and can be set as appropriate depending on the situation of the reduction reaction, but the amount of hydrogen required until the reduction is completed is calculated by TPR analysis of the unreduced catalyst, and usually the amount of hydrogen required is calculated by TPR analysis of the unreduced catalyst. 5 times or more, preferably 10 times or more, more preferably 20 times or more. Further, it is usually 5000 times or less, preferably 1000 times or less. If it is above the lower limit, hydrogen deficiency will not occur, and if it is below the upper limit, unnecessary reducing gas will not be consumed, which will be economically advantageous.
The rotation speed of the batch type rotary kiln is not particularly limited, but the faster the rotation speed, the better the contact efficiency with hydrogen, but the wear of the catalyst will occur, so it is usually carried out at 0.5 to 10 rpm, preferably 0.5 to 5 rpm. .

(Oxidation 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 support is usually controlled. Particularly when producing a large amount of catalyst, it is preferable that the catalyst be stabilized by oxidation. The metal-supported catalyst obtained by reduction is in a state in which the metal components are reduced and highly dispersed. By performing oxidation stabilization, compared to taking it out into the air as it is, the possibility of metal sintering due to sudden heat generation is reduced, and ignition (if it is a combustible carrier, it will ignite itself, and it will also cause the surrounding combustibles to ignite). This is preferable because it can also reduce the possibility of ignition. By stabilizing it under controlled conditions, it is possible to maintain high dispersibility and exhibit high activity in the subsequent hydrogenation reaction.
The method of oxidation stabilization is not particularly limited, but includes a method of adding water to the catalyst, a method of pouring the catalyst into water, a method of oxidation stabilization with a low oxygen concentration gas diluted with an inert gas under circulation, and a method of oxidation stabilization. There are methods such as stabilization with carbon dioxide. Among these, the method of adding water to the catalyst, the method of pouring the catalyst into water, the method of oxidation stabilization with a gas with a low oxygen concentration, and the method of oxidation stabilization with a gas with a low oxygen concentration are more preferable (hereinafter referred to as (referred to as "slow oxidation method"), and it is particularly preferable to oxidize and stabilize a gas with a low oxygen concentration under circulation.

The oxygen concentration during oxidation stabilization with a gas with a low oxygen concentration is not particularly limited, but the oxygen concentration at the start of slow oxidation is usually 0.2% by volume or more, preferably 0.5% by volume or more, while 10% by volume. The content is preferably 8% by volume or less, more preferably 7% by volume or less. When it is at least the lower limit, the time required for complete oxidation stabilization can be shortened and stabilization is sufficient. On the other hand, if it is below the upper limit, the catalyst will not reach a high temperature, so there is no risk of deactivation. Note that in order to create a gas with a low oxygen concentration, it is preferable to dilute air with an inert gas, and nitrogen is more preferable as the inert gas.

The oxygen concentration during gradual oxidation may be carried out as it was at the start of gradual oxidation, but if the internal temperature of the catalyst becomes high and the catalyst does not deteriorate, the oxygen concentration may be changed gradually after starting gradual oxidation. The oxygen concentration may be increased.
When slow oxidation is stable at a low oxygen concentration, it is preferable to control the catalyst temperature so that it does not exceed 130°C. When the temperature of the catalyst is 130° C. or lower, rapid oxidation does not proceed, so sintering of the catalyst does not proceed, and the strength of the carrier is maintained without decreasing. From the above point of view, it is preferable to control the oxygen concentration and flow rate so that the temperature of the catalyst does not exceed 120°C, and even more preferably does not exceed 110°C.

Methods for oxidation stabilization using low oxygen concentration gas include passing low oxygen concentration gas through a catalyst in a fixed bed, and passing low oxygen concentration gas through a catalyst that is left stationary on a tray or belt. There is a method in which gas with a low oxygen concentration is passed through a fluidized catalyst.
The better the dispersibility of the supported metal on the supported metal catalyst, the more rapid the oxidation stabilization will be, and the more oxygen will be reacted. A method of flowing a gas with a low oxygen concentration through a fluidized catalyst is preferred, and a method of flowing a gas with a low oxygen concentration through a fluidized catalyst is particularly preferred.

(How to store catalyst)
When storing the metal-supported catalyst of the present invention, it is preferable to store it in an atmosphere with an oxygen concentration of 15% by volume or less. By storing in such an atmosphere, if oxidation proceeds slowly even after oxidation stabilization, oxidation can proceed slowly in a closed container. Although the lower limit of the oxygen concentration is not particularly limited, it is usually preferably 0.2% by volume or more in order to promote oxidation.
In addition, since the gas-stabilized catalyst is highly hygroscopic, which poses a major problem in non-aqueous reactions, it is preferable to store it in a closed container.

<Application>
The catalyst of the present invention is suitable as a catalyst for reduction reactions, and is preferably used, for example, in the hydrogenation of carboxylic acids and/or carboxylic esters. In other words, it is suitable for an alcohol production method in which a carboxylic acid and/or a carboxylic ester is brought into contact with the metal-supported catalyst of the present invention and reduced to obtain an alcohol corresponding to each of the carboxylic acid and/or the carboxylic ester. used for. As the carboxylic acid or carboxylic ester to be subjected to the reduction reaction, any industrially easily available carboxylic acid or carboxylic ester can be used.
Examples of carboxylic acids and/or carboxylic acid esters that can be subjected to the reduction reaction using the catalyst of the present invention include acetic acid, butyric acid, lauric acid, oleic acid, linoleic acid, linolenic acid, stearic acid, palmitic acid, etc. Aliphatic chain carboxylic acids such as cyclohexanecarboxylic acid, naphthenic acid, cyclopentanecarboxylic acid; oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid , aliphatic polycarboxylic acids such as sebacic acid, cyclohexanedicarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,3,4-cyclohexanetricarboxylic acid, bicyclohexyldicarboxylic acid, decahydronaphthalene dicarboxylic acid; phthalic acid, isophthalic acid Examples include aromatic carboxylic acids such as 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 that does not contain any functional group other than a carboxyl group, and even more preferably is a dicarboxylic acid represented by formula (2), which contains no functional groups other than carboxyl groups, and has 20 or less carbon atoms.
HOOC-R ¹ -COOH (2)
(In the formula, R ¹ may have a substituent and is an aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms other than the substituent.)
Particularly preferred are aliphatic or alicyclic polycarboxylic acids having 4 to 14 carbon atoms, or esters thereof, since they have high activity and high selectivity in the reduction reaction.
In the present invention, it is particularly preferable to use 1,4-cyclohexanedicarboxylic acid or an ester thereof as a reactant to produce the corresponding alcohol through a reduction reaction. That is, it is preferable to use a method for producing alcohol in which 1,4-cyclohexanedicarboxylic acid or an ester (diester) of 1,4-cyclohexanedicarboxylic acid is used as a raw material, and this is brought into contact with the catalyst of the present invention and reduced.

When esters of these carboxylic acids are used, lower alcohols such as methanol, ethanol, i-propanol, and n-butanol can be used as the alcohol component.
It is also possible to esterify with the same alcohol as the alcohol obtained by reduction. In this case, there is an advantage that it is not necessary to separate the alcohol produced in the subsequent hydrogenation reaction.

Although the reduction reaction using the catalyst of the present invention can be carried out without a solvent or in the presence of a solvent, it is usually carried out in the presence of a solvent.
As a solvent, usually water, lower alcohols such as methanol and ethanol, alcohols of reaction products, ethers such as tetrahydrofuran, dioxane, and ethylene glycol dimethyl ether, and hydrocarbons such as hexane and decalin can be used. . These solvents can be used alone or in combination of two or more.
Particularly when reducing carboxylic acid, it is preferable to use a solvent containing water for reasons such as solubility.
The amount of the solvent used is not particularly limited, but it is usually about 0.1 to 20 times the mass of the carboxylic acid or carboxylic acid ester used as the raw material, preferably 0.5 to 10 times the mass, more preferably 1 It is preferable to use about 10 to 10 times the amount by mass.

The reduction reaction using the catalyst of the present invention is usually carried out under pressure of hydrogen gas. The reaction is usually carried out at a temperature of 100 to 300°C, preferably 150 to 300°C. The reaction pressure is 1 to 30 MPa, preferably 1 to 25 MPa, and more preferably 5 to 25 MPa.
The reduction reaction using the catalyst of the present invention can be carried out in both liquid phase and gas phase, but it requires huge equipment to vaporize the carboxylic acid/carboxylic acid ester and to carry out the reduction reaction while maintaining the gaseous state. However, it is preferable to carry out the process in a liquid phase since it requires even more energy.

Also included within the scope of the present invention is a method for hydrogenating carboxylic acids and/or carboxylic esters in which the catalyst of the present invention is brought into contact with the carboxylic acids and/or carboxylic esters.

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

<TPR measurement method>
0.1 g of the catalyst was placed in a narrow quartz tube, and 10% H ₂ /He was flowed at a rate of 20 ml/min, and the tube was maintained until hydrogen replacement in the system was completed and the H ₂ concentration became stable. Thereafter, the temperature was raised to 700° C. at a constant rate for 60 minutes. During that time, the amount of hydrogen at the outlet was continuously measured using a mass spectrometer, and the amount of absorbed hydrogen was calculated.

<How to check reaction activity of catalyst>
The reaction activity and selectivity of the catalyst obtained in the present invention were confirmed using a hydrogenation reaction of 1,4-cyclohexanedicarboxylic acid (CHDA) to produce 1,4-cyclohexanedimethanol (CHDM).
In a 200 mL induction stirring autoclave made of Hastelloy C (registered trademark) (hereinafter sometimes referred to as "reactor"), 40 g of water, CHDA (mixture of cis and trans forms: manufactured by Tokyo Chemical Industry Co., Ltd.) ) and 2 g of the catalyst to be evaluated, and after purging the inside of the reactor with hydrogen, the hydrogen partial pressure was set to 1 MPa, and under stirring at 1000 rpm (the rate of hydrogen supply was not limited by the rate of stirring being too slow, and the rate of stirring was too high). The reactor was heated to a predetermined temperature and reaction pressure of 8.5 MPa, and the reaction was started at 240°C. Hydrogen was continuously supplied into the reactor from a hydrogen pressure accumulator, and the reaction was carried out at 240° C. and a constant pressure of 8.5 MPa for 3 hours. After the reaction was completed, the presence or absence of cracks in the catalyst was visually confirmed. Reactions in which cracking of the catalyst occurred at this time were excluded because the apparent reaction rate would be high and the selectivity could not be accurately compared.
The resulting reaction solution was subjected to neutralization titration with NaOH to determine the conversion rate of carboxyl groups, and the product was analyzed using a gas chromatograph. The main product was the target product CHDM, and the two main by-products were cyclohexane methanol (CHM) and 4-methylcyclohexane methanol (MCHM). Since almost the entire amount was CHDM except for the two types of by-products mentioned above, the catalyst performance was compared based on the conversion rate of carboxyl groups and the yield of by-products.

(Comparative example 1)
A catalyst was prepared in accordance with Example 4 of JP-A No. 2001-9277 using a cylindrical activated carbon (R1 EXTRA manufactured by Cabot Norit) carrier having a diameter of 1 mm and a length of 2 to 5 mm. _Specifically , ruthenium _chloride hydrate _{( RuCl 3 .} SnCl ₂ .2H ₂ O) was dissolved in a dilute hydrochloric acid solution, and activated carbon treated with nitric acid was added thereto. The solvent was removed and dried, and the dried catalyst was treated in an ammonium bicarbonate solution, followed by filtration, washing, and drying to prepare a metal support. In the method for preparing the metal support, 1.1 ml of 0.3% dilute hydrochloric acid was used for each gram of activated carbon used as water for dissolving the metal chloride. The amount of metal chloride charged is such that when the entire amount is supported, hydrogen reduced, and stabilized by oxidation, the metal content in the supported catalyst is 5.5% by mass of Ru, 2.4% by mass of Pt, and 6.4% by mass of Sn. The amount was determined to be mass % (hereinafter, all supported amounts of metals are expressed in mass %). Further, the ammonium bicarbonate used was used as a 11% by mass aqueous solution in a molar amount 1.7 times that of chlorine in the metal chloride, and water at 90° C. was used for washing.
The obtained metal support was reduced at 500° C. in a hydrogen stream, and then oxidized and stabilized in a diluted oxygen atmosphere to obtain a catalyst. Hereinafter, it will be referred to as a "reduction catalyst."
The reaction was carried out with this catalyst. Table 1 shows the conversion rate and the yield of by-products.
Note that the metal type column in Table 1 displays the compounds used for metal types other than ruthenium, platinum, and tin.

(Comparative example 2)
Fe(III) acetylacetonate (Fe(acac) ₃ ) was supported on the reduction catalyst obtained in Comparative Example 1, and the catalyst was prepared so that after reduction, the supported amount of Fe was 0.1% by mass. . Specifically, using 0.86 ml of tetrahydrofuran solvent per 1 g of reduction catalyst, a predetermined amount of Fe(acac) ₃ was dissolved, approximately 10 g of the reduction catalyst obtained in Comparative Example 1 was added, and after stirring, the mixture was left for 1 hour. did. Thereafter, the mixture was evaporated at 80° C. for 1 hour under a reduced pressure of 1 kPa, and then placed in a glass tube, set in an electric furnace, and dried at 150° C. for 2 hours while flowing argon at 5 L/hour.
2.5 g of the dried catalyst was again charged into the glass tube, set in an electric furnace, and reduced at 500° C. for 2 hours while flowing hydrogen at 5 L/hour. Thereafter, it was cooled under argon flow, and stabilized under flow of 6 volume % oxygen/nitrogen at room temperature to obtain a 0.1% Fe-supported catalyst.
Using this catalyst (the amount of catalyst was such that the amount of reduction catalyst used in 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)
Except in Comparative Example 2, iron (III) chloride hexahydrate (FeCl ₃ .6H ₂ O) was used instead of Fe(III) acetylacetonate (Fe(acac) ₃ ) and water was used as the solvent. An Fe-supported catalyst was obtained in the same manner as in Example 1 so that the amount of Fe metal was 0.2% by mass. Using this catalyst, the same reaction as in Comparative Example 1 was carried out. The results are shown in Table 1.

(Comparative example 4)
In Comparative Example 2, a 0.5% Fe-supported catalyst was obtained in the same manner as in Comparative Example 2, except that Fe(acac) ₃ was used so that the amount of Fe metal was 0.5% by mass. A reaction similar to Comparative Example 1 was carried out using this catalyst. The results are shown in Table 1.

(Comparative example 5)
In Comparative Example 3, a 0.5% Fe-supported catalyst was obtained in the same manner as in Comparative Example 3, except that FeCl ₃ .6H ₂ O was used so that the amount of Fe metal was 0.5% by mass. A reaction similar to Comparative Example 1 was carried out using this catalyst. The results are shown in Table 1.

(Reference example 1)
Comparative Example 3 except that chromium (III) chloride hexahydrate (CrCl ₃ .6H ₂ O) was used instead of iron chloride (III) hexahydrate (FeCl ₃ .6H ₂ O). A 0.2% mass Cr-supported catalyst was obtained in the same manner as in 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)
The same method as Comparative Example 2 except that in Comparative Example 2, Cr(III) acetylacetonate (Cr(acac) ₃ ) was used instead of Fe(III) acetylacetonate (Fe(acac) ₃ ). A 0.5% Cr-supported catalyst was obtained. Using this catalyst, the same reaction as in Comparative Example 1 was carried out. The results are shown in Table 1.

(Comparative example 6)
In Comparative Example 2, ammonium paramolybdate (ammonium molybdate (VI) tetrahydrate ((NH ₄ ) ₆ Mo ₇ O _24.4H ) was used instead of Fe(III) acetylacetonate (Fe(acac) ₃ ). A 0.5% Mo-supported catalyst was obtained in the same manner as in Comparative Example 2, except that ₂ O)) was used and water was used as the solvent. Using this catalyst, the same reaction as in Comparative Example 1 was carried out. The results are shown in Table 1.

(Comparative example 7)
RuCl _{3.xH 2} O (Ru content 41.9%) 1.131 g, H ₂ PtCl _{6.6H 2} O 0.547 g, SnCl _{2.2H 2} O 0.883 g, FeCl _{3.6H 2} O 1.196 g. Dissolved in 0.3% hydrochloric acid solution. 7.41 g of activated carbon treated with nitric acid as in Comparative Example 1 was added to this solution, and after thorough stirring, it was left to stand for 3 hours. After 3 hours, it was dried in an evaporator, then transferred to a firing tube, and dried for 2 hours at 150°C under argon gas flow. This catalyst was added to an aqueous 11% by mass ammonium bicarbonate solution corresponding to 1.7 equivalents of the total chlorine amount of the metal chloride used, treated for 1 hour, filtered, washed with 90°C water, and dried in an evaporator. . The dried catalyst was transferred to a calcining tube and additionally dried at 150°C under argon gas flow. 2.5 g of the additionally dried catalyst was reduced at 500°C under hydrogen flow, and after cooling, it was stabilized with 6% oxygen/nitrogen. A catalyst with 5.5% Ru-2.4%Pt-5.4%Sn-0.47%Fe/activated carbon (calculated value on a charging basis) was prepared by carrying out four components at once (Table 1, it is written as “FeCl ₃ all at once”). A reaction similar to Comparative Example 1 was carried out using 2 g of this catalyst. The results are shown in Table 1.

(Example 1)
FeCl ₃ .6H ₂ O and CrCl ₃ .6H 2 O were used in the reduction catalyst obtained in Comparative Example 1 so that the Fe metal content was 0.2% and the Cr metal content was _0.2 %, and water was used as the solvent. A 0.2% Fe-0.2% Cr supported catalyst was obtained in the same manner as in Comparative Example 2 except that Using this catalyst, the same reaction as in Comparative Example 1 was carried out. The results are shown in Table 1.

(Example 2)
FeCl ₃ .6H ₂ O and CrCl ₃ .6H ₂ O were used in the reduction catalyst obtained in Comparative Example 1 so that the Fe metal content was 0.4% and the Cr metal content was 0.1%, and water was used as the solvent. A 0.4% Fe-0.1% Cr supported catalyst was obtained in the same manner as in Comparative Example 2 except that Using this catalyst, the same reaction as in Comparative Example 1 was carried out. The results are shown in Table 1.

(Example 3)
FeCl _{3.6H 2} O and (NH ₄ ) ₆ Mo ₇ O _{24.4H 2} O were added to the reduction catalyst obtained in Comparative Example 1 so that the Fe metal amount was 0.2% and the Mo metal amount was 0.2%. A 0.2% Fe-0.2% Mo supported catalyst was obtained in the same manner as in Comparative Example 2 except that water was used as the solvent. A reaction similar to Comparative Example 1 was carried out using this catalyst. The results are shown in Table 1.

(Example 4)
FeCl _{3.6H 2} O, ammonium molybdate (VI) tetrahydrate ((NH ₄ ) ₆ Mo ₇ O ₂₄ ·4H ₂ O) and a 0.4% Fe-0.1% Mo supported catalyst was obtained in the same manner as in Comparative Example 2, except that a 3% HCl aqueous solution was used as the solvent. Using this catalyst, the same reaction as in Comparative Example 1 was carried out. The results are shown in Table 1.

 

As is clear from Table 1, according to the catalyst of the present invention supporting Fe and Cr and the catalyst of the present invention supporting Fe and Mo, the main by-product cyclohexane methanol ( CHM), and the yield of 4-methylcyclohexanemethanol (MCHM) can be lowered. On the other hand, in Comparative Examples 2 to 5, in which only iron was supported, and Comparative Example 6, in which only molybdenum was supported, some effects were observed when compared with unmodified catalysts that did not modify iron, etc. It can be seen that the catalyst is inferior when compared to the catalyst of the invention.
As described above, it can be seen that the catalyst of the present invention maintains a high conversion rate and suppresses the yield of by-products to 60% or less compared to when no catalyst is added, showing excellent effects.

According to the present invention, by adding a plurality of new specific metals in combination to a conventional reduction catalyst, the yield of by-products is extremely reduced and the yield of the target product is improved. The present invention is an extremely useful technology industrially because the extremely low yield of by-products makes it possible to omit or simplify the precise purification process when subsequently used as a polymer raw material. .

Claims (8)

1. A metal-supported catalyst used for the hydrogenation of carboxylic acids and/or carboxylic acid esters, in which ruthenium, tin, and platinum are supported on a carrier, wherein the metal-supported catalyst further supports iron, and chromium and/or molybdenum. metal-supported catalyst.
2. The amount of iron supported is 0.01% by mass or more and 4% by mass or less, and the total amount of chromium and/or molybdenum supported is 0.01% by mass or more and 2% by mass or less with respect to the total mass of the metal supported catalyst. The metal-supported catalyst according to claim 1.
3. The metal-supported catalyst according to claim 1 or 2, wherein the support is a carbonaceous support.
4. The metal-supported catalyst according to claim 1 or 2, wherein the total supported amount of ruthenium, tin, platinum, iron, molybdenum, and chromium based on the total mass of the metal-supported catalyst is 5% by mass or more.
5. The metal-supported catalyst according to claim 1 or 2, wherein the metal-supported catalyst is prepared through hydrogen reduction.
6. Production of alcohol by contacting a carboxylic acid and/or a carboxylic acid ester with the metal-supported catalyst according to claim 1 or 2 and reducing the carboxylic acid and/or a carboxylic acid ester to obtain an alcohol corresponding to each of the carboxylic acid and/or the carboxylic acid ester. Method.
7. A method for hydrogenating a carboxylic acid and/or a carboxylic acid ester, which comprises bringing the metal-supported catalyst according to claim 1 or 2 into contact with the carboxylic acid and/or the carboxylic acid ester.
8. The method for producing alcohol according to claim 6, wherein the carboxylic acid is 1,4-cyclohexanedicarboxylic acid, and the carboxylic acid ester is an ester of 1,4-cyclohexanedicarboxylic acid.