JP6314411B2 - Hydrogenation catalyst for aromatic carboxylic acids and process for producing the same - Google Patents

Description

The present invention relates to a hydrogenation catalyst for an aromatic ring of an aromatic carboxylic acid. Specifically, the present invention relates to a catalyst in which the hydrogenation catalyst is a catalyst in which ruthenium and palladium are co-supported, and ruthenium and palladium coexist in the same particle on the support surface.

Many noble metal catalysts for hydrogenating an aromatic ring of an aromatic carboxylic acid have been studied so far. As a catalyst for directly hydrogenating an aromatic ring of an aromatic carboxylic acid, many rhodium catalysts that undergo a hydrogenation reaction under mild conditions are currently being studied (Non-Patent Document 1, Non-Patent Document 2, and Patent Document 1). Patent Document 2). The rhodium catalyst is highly active as a hydrogenation catalyst for aromatic carboxylic acids, and has the advantage that the side reaction does not proceed and the selectivity of the product increases. Although rhodium has such excellent catalytic ability, there are several problems in industrialization. The first point is that it is very expensive, and the burden of initial investment for the catalyst becomes large during industrialization. The second point is that the rate of decrease in the activity of the catalyst is fast, and the activation operation must be frequently performed in order to use the catalyst for a long period of time. Although it is possible to construct a process incorporating activation, a catalyst capable of adopting a simpler process is required for industrialization (Patent Document 1).

Ruthenium is an example of a noble metal that can hydrogenate aromatic carboxylic acids and is inexpensive. In general, when a ruthenium catalyst is used for hydrogenation of an aromatic carboxylic acid, it is known that not only hydrogenation of the aromatic ring but also reduction of the side chain carboxyl group occurs (Non-patent Document 3). The selectivity of the formula carboxylic acid is low. In order to use a ruthenium catalyst having such an activity for hydrogenation of an aromatic carboxylic acid, it is known that it is necessary to convert the carboxylic acid into an ester. Two processes, such as hydrolysis of alicyclic carboxylic acid ester, will increase (Patent Document 3 and Patent Document 4). Alternatively, it is known that a ruthenium catalyst can be used for hydrogenation of an aromatic carboxylic acid by converting a carboxylic acid into an inorganic salt such as a sodium salt (Patent Document 5). In particular, the two steps of derivatization of aromatic carboxylic acid into inorganic salt and desalting of alicyclic carboxylic acid inorganic salt are increased.

As a catalyst that uses ruthenium, which is a relatively inexpensive noble metal, and does not cause the same activity as the rhodium catalyst and the decrease in activity seen in the rhodium catalyst, there is a catalyst in which ruthenium and palladium are co-supported on a carrier. It is known that when a supported catalyst is used, an alicyclic carboxylic acid can be produced by an industrially simple method (Patent Document 6).

In general, inexpensive chlorides are used when producing noble metal catalysts. When a catalyst is produced using chloride as a raw material, depending on the production method, chlorine gas or hydrogen chloride gas may be generated, which may corrode the catalyst production apparatus. Therefore, the maintenance cost of a calcination furnace and a reduction device is required, and the catalyst manufacturing cost increases. In order to prevent corrosion of the catalyst production apparatus, a method is known in which a ruthenium-tin-based supported catalyst is treated with an inorganic alkali to remove halogen contained in the catalyst (Patent Document 7).

JP 2008-63263 A Japanese Patent No. 4622406 Japanese Patent No. 3834836 JP 2006-045166 A U.S. Pat. No. 3,444,237 International Publication No. 2012-117976 JP 2001-9277 A

Journal of Organic Chemistry, 1966, 31, p.3438-3439 Chemistry a European Journal, 2009, Vol. 15, p.6953-6963 Handbook of Heterogeneous Catalytic Hydrogenation for Organic Synthesis, p.387-391, Sigeo NISHIMURA, JOHN WILEY & SONS, INC.

The catalyst described in Patent Document 6 is useful as a hydrogenation catalyst for an aromatic ring of an aromatic carboxylic acid, but further improvement in activity is also desired. Further, according to the study by the present inventors, when the catalyst is produced using chloride as a raw material, chlorine gas is generated in the calcination step and hydrogen chloride gas is generated in the reduction step, and the calcination furnace and the reduction device may be corroded. I understood that. As described above, Patent Document 7 introduces a method of treating a catalyst with an inorganic alkali and removing a halogen contained in the catalyst. However, when a ruthenium-palladium co-supported catalyst is treated with an inorganic alkali, catalytic activity is obtained. Turned out to be lower.
An object of the present invention is to provide a more active ruthenium-palladium co-supported catalyst, and further to prevent generation of chlorine gas when preparing the catalyst using chloride, thereby producing a catalyst production apparatus. Is to reduce the maintenance cost of the manufacturing apparatus and reduce the catalyst manufacturing cost. If the catalytic activity increases, the amount of catalyst used can be reduced, leading to a reduction in the production cost of the alicyclic carboxylic acid, and a more dominant production process can be constructed.

As a result of diligent investigations to increase the activity of the ruthenium-palladium co-supported catalyst, the present inventors made contact with an organic alkali after supporting the ruthenium compound and the palladium compound on the support, and thereby the particles containing ruthenium and palladium were supported. It has been found that the metal dispersibility is increased, the catalytic activity is improved, and that the generation of chlorine gas during the preparation of the catalyst can be prevented according to this method, and the present invention has been completed.

That is, the present invention relates to the following co-supported catalysts [1] to [7].
[1] A catalyst in which ruthenium and palladium are co-supported on a carrier, wherein the ruthenium and palladium are present in the form of particles containing both on the carrier surface, and the metal dispersion is 46% or more. Ruthenium-palladium co-supported catalyst.
[2] The co-supported catalyst according to [1], wherein the carrier is one or a combination of two or more selected from the group consisting of activated carbon, alumina, zirconia, ceria, titania and silica.
[3] The co-supported catalyst according to [1], wherein the support is silica.
[4] The co-supported catalyst according to [1] to [3], which is used as a hydrogenation catalyst.
[5] The co-supported catalyst according to [4], which is a hydrogenation catalyst for an aromatic ring of an aromatic carboxylic acid.
[6] The co-supported catalyst according to [5], wherein the aromatic carboxylic acid is a compound represented by the general formula (1), (2) or (3).

(In formula (1), R _{1 to} R ₆ are each COOH, CH ₂ OH, CH ₃ , OH or H, and at least one of R _{1 to} R ₆ is COOH)

(In formula (2), R _{1 to} R ₈ are each COOH, CH ₂ OH, CH ₃ , OH or H, and at least one of R _{1 to} R ₈ is COOH)

(In formula (3), R _{1 to} R ₁₀ are each COOH, CH ₂ OH, CH ₃ , OH or H, and at least one of R _{1 to} R ₁₀ is COOH)
[7] The co-supported catalyst according to [5], wherein the aromatic carboxylic acid is trimellitic acid, trimesic acid or pyromellitic acid.

Since the ruthenium-palladium co-supported catalyst in the present invention has high catalytic activity, the aromatic ring of the aromatic carboxylic acid can be efficiently hydrogenated to produce an alicyclic carboxylic acid.

The ruthenium-palladium co-supported catalyst of the present invention (hereinafter sometimes referred to as “co-supported catalyst of the present invention”) is a catalyst in which ruthenium and palladium are co-supported on a support, and both of ruthenium and palladium are supported on the support surface. It is a co-supported catalyst that exists in the form of contained particles and has a metal dispersity of 46% or more.

The support used in the co-supported catalyst of the present invention is not particularly limited as long as it can support ruthenium and palladium. The shape of the support (for example, powder or molded product) and the physical properties of the support (for example, specific surface area, average pore diameter, etc.) ) Is not limited. Specific examples include activated carbon, alumina, zirconia, ceria, titania, silica, silica alumina, zeolite, chromium oxide, tungsten oxide, ion exchange resin, and synthetic adsorbent. These may be used alone or in admixture of two or more. Among these, activated carbon, alumina, zirconia, ceria, titania, and silica are preferable, and silica is particularly preferable. The particle size (average particle size) of the carrier is preferably 1 μm to 300 μm when the reaction is carried out in a suspended bed and 0.3 mm to 10 mm when the reaction is carried out in a fixed bed.

The co-supported catalyst of the present invention is a catalyst that exists in the form of particles containing ruthenium and palladium on the support surface, that is, the ruthenium and palladium coexist in the same particle. Ruthenium and palladium coexist in the same particle and are close to each other, thereby exhibiting high activity and selectivity for hydrogenation of aromatic rings of aromatic compounds.

The size of the particles in which ruthenium and palladium coexist on the support surface of the co-supported catalyst of the present invention is not particularly limited as long as ruthenium and palladium coexist. However, if the size of the particles in which ruthenium and palladium coexist is large, the outer surface area of the particles decreases, and the supported ruthenium and palladium are not efficiently used in the reaction, so the ruthenium and palladium are efficiently hydrogenated. For use in the reaction, a smaller particle size is suitable, preferably 1-50 nm, more preferably 1-15 nm. This particle size can be easily measured by a method such as a transmission electron microscope.

There is no limitation on the amount of ruthenium and palladium supported in the co-supported catalyst of the present invention. Specifically, the total supported amount of ruthenium and palladium is preferably 0.5 to 10% by mass, more preferably 0.5 to 5% by mass, based on the entire co-supported catalyst. The total supported amount of ruthenium and palladium can be measured by fluorescent X-ray analysis or the like.

The ratio of ruthenium and palladium in the co-supported catalyst of the present invention is not limited as long as ruthenium and palladium coexist in the particles on the support surface. The specific ratio of ruthenium and palladium to the total amount of ruthenium and palladium is preferably 1 to 99% by mass, more preferably 10 to 90% by mass, and still more preferably 20 to 80% by mass.

Since the co-supported catalyst of the present invention has a large metal dispersion and a large metal surface area (external surface area of metal particles), the supported metal is efficiently used for the reaction, and thus the reaction rate is increased. Metal dispersion can be measured by the CO pulse method. After pretreatment of the catalyst under a hydrogen stream at 250 ° C for 15 minutes, the amount of CO adsorbed on the catalyst at 50 ° C was calculated, and assuming that two molecules of CO adsorb on one metal molecule, the metal surface area and metal dispersion degree were Can be calculated. Specifically, the CO adsorption amount, the metal surface area, and the metal dispersion degree can be determined by the methods described in the examples. The metal dispersion degree of a preferable catalyst is 46% or more, more preferably 47% or more. When the metal dispersity is smaller than this value, the metal surface area becomes small, and the supported metal is not efficiently used for the reaction, so that the catalyst does not exhibit high activity. The metal surface area is preferably 190 m ² / g-metal or more.

The co-supported catalyst of the present invention is produced by preparing a catalyst precursor by supporting a ruthenium compound and a palladium compound on a carrier and then bringing the catalyst precursor into contact with an organic alkali.
The method of supporting the ruthenium compound and the palladium compound on the support is not limited as long as ruthenium and palladium can coexist on the same particle on the support surface of the co-supported catalyst, and a third metal component is added in addition to ruthenium and palladium. It is also possible. Specific examples of the preparation method include an ion exchange method, an impregnation method, and a deposition method, and an impregnation method and a deposition method are preferable.
The order in which the ruthenium compound and the palladium compound are supported on the carrier is not particularly limited. Specifically, a method of simultaneously supporting, a method of sequentially supporting, and the like can be mentioned.
As a method for preparing a catalyst precursor in which a ruthenium compound and a palladium compound are supported on a support, the method for preparing a catalyst disclosed in Patent Document 6 can be suitably used.

As the ruthenium compound or palladium compound serving as a supply source of ruthenium and palladium, known salts or complexes such as chlorides, nitrates and acetates can be used. Of these, inexpensive chlorides are used.

In the present invention, after preparing a catalyst precursor by supporting ruthenium chloride and palladium chloride on a carrier, it is preferable to contact the catalyst precursor with an organic alkali (hereinafter sometimes referred to as “alkali treatment”). As a result, chlorine (atoms) in the catalyst precursor is removed, and further, the metal dispersion degree of the particles containing ruthenium and palladium is increased, and the catalytic activity is improved.

The type of organic alkali used for the alkali treatment is not particularly limited as long as it is an alkali that forms a hydroxide by reacting with ruthenium chloride and palladium chloride (hereinafter sometimes collectively referred to as “metal chloride”). Specific examples include quaternary ammonium salts and amines. Among these, tetraalkylammonium hydroxide is preferable, and tetramethylammonium hydroxide and tetraethylammonium hydroxide are particularly preferable.

The amount of the organic alkali substance added during the alkali treatment is preferably 1 or more and 10 or less as the ratio of the chlorine atom in the catalyst precursor to the substance amount. If it is less than 1, metal chloride remains even after alkali treatment, and chlorine gas and hydrogen chloride gas are generated during firing and reduction, which may cause corrosion of the device. On the other hand, if it is larger than 10, not only removal from the catalyst becomes difficult, but also the excess organic alkali and the silica as the carrier may react to dissolve the silica.

The organic alkali can be used in the form of a solution, and the solvent used in the solution is not particularly limited as long as part or all of the organic alkali is dissolved, but it is preferably dissolved in water to form an aqueous solution. The concentration of the organic alkali at this time is not limited as long as it is completely dissolved in water. When the concentration is low, the amount of the required organic alkali aqueous solution increases, and the time required for the alkali treatment increases. Conversely, when the concentration is high, the organic alkali and the silica that is the carrier react with each other, and the silica is easily dissolved. Specifically, it is preferable to perform the treatment in the range of the organic alkali concentration in the range of 1 to 50% by mass.

The alkali treatment is preferably performed by adding an organic alkali to a catalyst precursor supporting ruthenium chloride and palladium chloride. Specifically, an organic alkali aqueous solution is added to the catalyst precursor to form ruthenium hydroxide and palladium hydroxide. The hydroxide is supported on the carrier by evaporating water in the added aqueous organic alkali solution. This operation may be performed a plurality of times. In that case, it is preferable to wash the resulting catalyst with water to remove the produced organic alkali chloride and excess organic alkali from the catalyst. The treated catalyst can be appropriately dried, calcined and reduced.

If the temperature at the time of performing an alkali treatment is more than the temperature which an organic alkali and a metal chloride react, there will be no restriction | limiting. If the temperature is too low, the reaction rate between the organic alkali and the metal chloride is slow, the time required for the alkali treatment becomes long, and unreacted metal chloride tends to remain. Conversely, increasing the temperature too much does not improve the effect. Specifically, the treatment can be performed in the range of 40 to 100 ° C.

When an organic alkali is added to the catalyst precursor to perform the alkali treatment, a capacity equal to or less than the pore volume of the catalyst precursor is added. When the volume of the organic alkali to be added is larger than the pore volume, the reaction between the metal chloride and the organic alkali does not occur on the support, and there is a possibility that metal particles not supported on the support are generated.

The co-supported catalyst of the present invention is useful as a catalyst for hydrogenating an aromatic ring of an aromatic compound, and is particularly suitable as a catalyst for producing an alicyclic carboxylic acid by hydrogenating an aromatic ring of an aromatic carboxylic acid. The aromatic carboxylic acid is not particularly limited as long as it is a compound having a carboxyl group in the aromatic ring, and a known aromatic carboxylic acid can be used. As such an aromatic carboxylic acid, those represented by the general formula (1), (2) or (3) can be used.

Specifically, aromatic monocarboxylic acids such as benzoic acid; phthalic acid, isophthalic acid, terephthalic acid, 1,2-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2, 3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,2'-biphenyldicarboxylic acid, 3,3'-biphenyldicarboxylic acid, 4, Aromatic dicarboxylic acids such as 4'-biphenyldicarboxylic acid; aromatic tricarboxylic acids such as hemimellitic acid, trimellitic acid, trimesic acid, 1,2,4-naphthalenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid; Melofuanic acid, planitic acid, pyromellitic acid, 3,3'4,4'-biphenyltetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, etc. The aromatic tetraca Bon acid; aromatic penta carboxylic acids such as benzene penta carboxylic acid; and aromatic hexacarboxylic acids, such as benzene hexacarboxylic acid. These may be used alone or in appropriate combination of two or more.

Among them, aromatic dicarboxylic acids having 2 to 4 carboxyl groups in the benzene ring, aromatic tricarboxylic acids, and aromatic tetracarboxylic acids are preferable, and specifically, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, Trimesic acid and pyromellitic acid are preferable, and trimellitic acid, trimesic acid, and pyromellitic acid are more preferable. These may be used alone or in appropriate combination of two or more.

A reaction solvent is preferably used for the hydrogenation reaction. The hydrogenation reaction solvent is not particularly limited as long as it dissolves the aromatic carboxylic acid and does not inhibit the reaction.
Specifically, alcohols such as water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol; diethyl ether, diisopropyl ether, n-butyl ether, cyclopentyl methyl ether And ethers such as tert-butyl methyl ether and THF; esters such as methyl acetate and ethyl acetate; ketones such as acetone and methyl ethyl ketone.
Of these, water, methanol, ethanol, 1-propanol and 2-propanol are preferable, and water is more preferable. These may be used alone or in admixture of two or more.

In the hydrogenation reaction, the aromatic carboxylic acid may be dissolved or suspended in a solvent, and the concentration is not particularly limited. The specific concentration of the aromatic carboxylic acid is preferably 1 to 50% by mass, more preferably 2 to 40% by mass, and still more preferably as the aromatic carboxylic acid with respect to the total of the aromatic carboxylic acid and the solvent. 2 to 20% by mass.

There is no limitation on the amount of catalyst used in the hydrogenation reaction, and it may be appropriately determined so as to achieve the desired reaction time in consideration of the content of ruthenium and palladium and the amount of aromatic carboxylic acid used in the reaction.

There is no restriction on the temperature of the hydrogenation reaction. If the temperature is too low, the reaction rate decreases, and the time required for completion of the hydrogenation reaction increases. Conversely, if the temperature is too high, the reaction rate increases and the hydrogenation reaction increases. Although the time required for completion of the reaction is shortened, the selectivity of the desired alicyclic carboxylic acid is lowered. The reaction can be carried out in the temperature range of 40 to 150 ° C, preferably in the temperature range of 40 to 100 ° C.

The hydrogen pressure of the hydrogenation reaction is not particularly limited. If the hydrogen pressure is low, the reaction rate decreases, and the time required for completing the hydrogenation reaction increases. Conversely, if the hydrogen pressure is high, the hydrogenation reaction is completed. Although the time required is shortened, the investment in the apparatus such as the breakdown voltage specification of the apparatus increases. Specifically, the hydrogenation reaction can be carried out in the range of 0.5 to 15 MPa, preferably 1 to 10 MPa.

The hydrogenation reaction is not limited to batch, semi-batch and continuous reaction modes. If the target production amount is small, a batch or semi-batch production process may be constructed, and if the production amount is large, a continuous production process may be constructed.

The hydrogenation reaction can be carried out by appropriately combining the amount of the aromatic carboxylic acid, the amount of the catalyst, the reaction temperature, the hydrogen pressure, and the reaction type to produce an alicyclic carboxylic acid having a desired selectivity in a desired reaction time. It becomes possible.

The co-supported catalyst of the present invention is pretreated by contacting with hydrogen before the hydrogenation reaction, in particular before contacting with a hydrogenation raw material such as aromatic carboxylic acid, thereby reducing the catalytic activity when the hydrogenation reaction is performed. Can be suppressed. Although the mechanism for suppressing the decrease in activity is not clear, it is conceivable that when the catalyst is brought into contact with hydrogen, hydrogen is adsorbed on ruthenium or palladium in the catalyst, thereby reducing the action of the aromatic carboxylic acid on these catalyst metals.

The co-supported catalyst of the present invention can be reused without performing an activation operation in a batch-type or semi-batch-type hydrogenation reaction because no significant decrease in activity is observed for each reaction. By carrying out the pretreatment in step 1, it is possible to further suppress the decrease in activity. Since the frequency | count that a catalyst can be reused increases, the replacement frequency of a catalyst can be reduced and alicyclic carboxylic acid can be produced more efficiently. Even in the continuous system, when the reaction is started after the hydrogen pretreatment is performed, the catalyst is not greatly reduced in activity over time, and the alicyclic carboxylic acid can be more efficiently produced.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
<Chlorine content>
The chlorine content in the catalyst precursor was calculated from the amounts of ruthenium chloride and palladium chloride charged.
The chlorine content in the catalyst other than the catalyst precursor was measured by energy dispersive X-ray spectroscopy (EDX, Hitachi S-3400N).
<CO adsorption amount, metal surface area, metal dispersion degree>
The amount of CO adsorption, metal surface area, and metal dispersion of the catalyst used were determined by the following methods.
Analyzing device: Nippon Bell Co., Ltd. Metal surface area measuring device
Before the measurement, the catalyst was pretreated at 250 ° C. for 15 minutes under a hydrogen stream, and then CO was adsorbed at 50 ° C. to determine the amount of adsorption. Moreover, the metal surface area and the metal dispersity were determined according to the following equations. The stoichiometric ratio was calculated as 2.
Metal dispersity (%) = CO adsorption (cm ³ ) x SF / 22414 x MW / C x 100
Metal surface area (m ² / g-metal) = CO adsorption (cm ³ ) × SF / 22414 × 6.02 × 10 ²³ × σ _m × 10 ^-18 / C
MW: Metal atomic weight (g / mol)
MW = (MW _Ru x wt% _Ru / MW _Ru + MW _Pd x wt% _Pd / MW _Pd ) / (wt% _Ru / MW _Ru + wt% _Pd / MW _Pd )
MW _Ru , MW _Pd : atomic weight of ruthenium, palladium (g / mol)
wt% _Ru , wt% _Pd : Ruthenium, palladium loading (mass%)
SF: Stoichiometric ratio
C: Metal weight in the measurement sample (g)
σ _m : cross section of one metal atom (nm ² )
<Conversion rate / selectivity>
The conversion rate of the aromatic carboxylic acid and the selectivity of the alicyclic carboxylic acid were obtained by derivatizing the reaction product into a methyl ester and analyzing it by gas chromatography.
<Reaction rate constant>
The reaction rate constant k was determined according to the following formula.
k = 1 / reaction time (hr) x ln (1 / (1-conversion (%) / 100))

<Preparation example>
0.647 g of ruthenium chloride n hydrate (manufactured by Wako Pure Chemical Industries) and 0.417 g of palladium chloride (manufactured by Wako Pure Chemical Industries) were dissolved in water. An aqueous solution in which ruthenium chloride and palladium chloride are dissolved in 10 g of silica gel (Fuji Silysia Chemical Caractect Q-6, particle size 75-150 μm) was added to a total weight of 60 g. Heating was carried out in a water bath under reduced pressure of the aspirator to evaporate the water, and ruthenium chloride and palladium chloride were supported on the carrier. Then, it was made to dry in air atmosphere and the catalyst precursor X was prepared. The chlorine content in the catalyst precursor X was 4.4%.

<Example 1>
1 g of catalyst precursor X was placed in a flask and heated to 60 ° C. in a water bath. To this, 0.5 ml of 15 wt% tetramethylammonium hydroxide aqueous solution (TMAH, manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the water was evaporated by reducing the pressure with an aspirator. This operation was repeated 6 times to react the metal chloride with TMAH. The water was completely evaporated by heating under reduced pressure of the aspirator. The obtained catalyst was washed with water to remove chlorine atoms and TMAH. It was dried at 150 ° C. for 2 hours in an air atmosphere (the chlorine content was below the detection limit). Thereafter, a ruthenium-palladium co-supported catalyst (2.5 wt% Ru-2.5 wt% Pd / SiO2, hereinafter referred to as “catalyst A”) was prepared by performing gas phase hydrogen reduction at 250 ° C. for 4 hours. Catalyst A had a CO adsorption amount of 3.8 cm ³ / g (STP), a metal surface area of 286 m ² / g-metal, and a metal dispersity of 70%.

A 200 ml SUS316 autoclave was charged with 0.4 g of catalyst A and 40 g of water. After replacing the gas phase part 3 times with nitrogen 1 MPa, the gas phase part was replaced 3 times with hydrogen 1 MPa to form a hydrogen atmosphere. The mixture was stirred at room temperature for 30 minutes with a magnetic stirring blade in a hydrogen atmosphere. Thereafter, the flange was opened, and 4 g of trimellitic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and 8 g of water were charged into the autoclave. After replacing the gas phase part 3 times with 1 MPa of nitrogen, the gas phase part was replaced 3 times with 1 MPa of hydrogen. The pressure was increased to 9 MPa with hydrogen, the temperature was raised to 50 ° C. while stirring with an electromagnetic stirring blade, and the reaction was stopped 60 minutes after the start of the temperature increase. When the reaction product is derivatized to a methyl ester and analyzed by gas chromatography, the conversion of trimellitic acid is 100% and the selectivity for hydrogenated trimellitic acid (1,2,4-cyclohexanetricarboxylic acid) is 97.7. %. The reaction rate constant at 30 minutes from the start of temperature increase was 4.6 hr ⁻¹ .

<Example 2>
1 g of catalyst precursor X was placed in a flask and heated to 60 ° C. in a water bath. 0.5 ml of 5 wt% tetraethylammonium hydroxide aqueous solution (TEAH) was added thereto, and the water was evaporated by reducing the pressure with an aspirator. This operation was repeated 12 times to react the metal chloride with TEAH. The water was completely evaporated by heating under reduced pressure of the aspirator. The obtained catalyst was washed with water to remove chlorine atoms and TEAH. It was dried at 150 ° C. for 2 hours in an air atmosphere (the chlorine content was below the detection limit). Thereafter, a ruthenium-palladium co-supported catalyst (2.5 wt% Ru-2.5 wt% Pd / SiO2, hereinafter referred to as “catalyst B”) was prepared by performing gas phase hydrogen reduction at 250 ° C. for 4 hours. Catalyst B had a CO adsorption amount of 3.4 cm ³ / g (STP), a metal surface area of 256 m ² / g-metal, and a metal dispersity of 63%.

A 200 ml SUS316 autoclave was charged with 0.5 g of catalyst B and 50 g of water. After replacing the gas phase part 3 times with nitrogen 1 MPa, the gas phase part was replaced 3 times with hydrogen 1 MPa to form a hydrogen atmosphere. The mixture was stirred at room temperature for 30 minutes with a magnetic stirring blade in a hydrogen atmosphere. Thereafter, the flange was opened, and 5 g of trimellitic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and 10 g of water were charged into the autoclave. After replacing the gas phase part 3 times with 1 MPa of nitrogen, the gas phase part was replaced 3 times with 1 MPa of hydrogen. The pressure was increased to 9 MPa with hydrogen, the temperature was raised to 50 ° C. while stirring with an electromagnetic stirring blade, and the reaction was stopped 60 minutes after the start of the temperature increase. When the reaction product is derivatized to a methyl ester and analyzed by gas chromatography, the conversion of trimellitic acid is 100%, and the selectivity for hydrogenated trimellitic acid (1,2,4-cyclohexanetricarboxylic acid) is 97.5. %. The reaction rate constant at 30 minutes from the start of temperature increase was 2.5 hr ⁻¹ .

<Example 3>
1 g of catalyst precursor X was placed in a flask and heated to 60 ° C. in a water bath. To this, 0.5 ml of 15 wt% tetraethylammonium hydroxide aqueous solution (TEAH) was added, and the pressure was reduced with an aspirator to evaporate water. This operation was repeated 6 times to react the metal chloride with TEAH. The water was completely evaporated by heating under reduced pressure of the aspirator. The obtained catalyst was washed with water to remove chlorine atoms and TEAH. It was dried at 150 ° C. for 2 hours in an air atmosphere (the chlorine content was below the detection limit). Thereafter, a ruthenium-palladium co-supported catalyst (2.5 wt% Ru-2.5 wt% Pd / SiO2, hereinafter referred to as “catalyst C”) was prepared by performing gas phase hydrogen reduction at 250 ° C. for 4 hours. The CO adsorption amount of catalyst C was 2.6 cm ³ / g (STP), the metal surface area was 192 m ² / g-metal, and the metal dispersion degree was 47%.

A 200 ml SUS316 autoclave was charged with 0.5 g of catalyst C and 50 g of water. After replacing the gas phase part 3 times with nitrogen 1 MPa, the gas phase part was replaced 3 times with hydrogen 1 MPa to form a hydrogen atmosphere. The mixture was stirred at room temperature for 30 minutes with a magnetic stirring blade in a hydrogen atmosphere. Thereafter, the flange was opened, and 5 g of trimellitic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and 10 g of water were charged into the autoclave. After replacing the gas phase part 3 times with 1 MPa of nitrogen, the gas phase part was replaced 3 times with 1 MPa of hydrogen. The pressure was increased to 9 MPa with hydrogen, the temperature was raised to 50 ° C. while stirring with an electromagnetic stirring blade, and the reaction was stopped 60 minutes after the start of the temperature increase. When the reaction product is derivatized to a methyl ester and analyzed by gas chromatography, the conversion of trimellitic acid is 100% and the selectivity for hydrogenated trimellitic acid (1,2,4-cyclohexanetricarboxylic acid) is 96.8. %. The reaction rate constant at 30 minutes from the start of temperature increase was 2.2 hr ⁻¹ .

<Comparative Example 1>
The catalyst precursor X 1g was calcined at 400 ° C. for 4 hours in an air atmosphere and subjected to gas phase hydrogen reduction at 250 ° C. for 4 hours, whereby a ruthenium-palladium co-supported catalyst (2.5 wt% Ru-2.5 wt% Pd / SiO2, (Hereinafter referred to as “Catalyst D”) was prepared. The generation of chlorine gas was confirmed at the time of firing. The CO adsorption amount of catalyst D was 1.8 cm ³ / g (STP), the metal surface area was 138 m ² / g-metal, and the metal dispersity was 34%.

A 200 ml SUS316 autoclave was charged with 0.5 g of catalyst D and 50 g of water. After replacing the gas phase part 3 times with nitrogen 1 MPa, the gas phase part was replaced 3 times with hydrogen 1 MPa to form a hydrogen atmosphere. The mixture was stirred at room temperature for 30 minutes with a magnetic stirring blade in a hydrogen atmosphere. Thereafter, the flange was opened, and 5 g of trimellitic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and 10 g of water were charged into the autoclave. After replacing the gas phase part 3 times with 1 MPa of nitrogen, the gas phase part was replaced 3 times with 1 MPa of hydrogen. The pressure was increased to 9 MPa with hydrogen, the temperature was raised to 50 ° C. while stirring with an electromagnetic stirring blade, and the reaction was stopped 60 minutes after the start of the temperature increase. When the reaction product is derivatized to a methyl ester and analyzed by gas chromatography, the conversion of trimellitic acid is 97.7% and the selectivity for hydrogenated trimellitic acid (1,2,4-cyclohexanetricarboxylic acid) is 96.8%. %. The reaction rate constant at 30 minutes from the start of temperature increase was 2.1 hr ⁻¹ .

<Comparative example 2>
1 g of catalyst precursor X was placed in a flask and heated to 60 ° C. in a water bath. To this, 0.5 ml of 0.2N (0.8 wt%) aqueous sodium hydroxide solution (NaOH, manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the water was evaporated by reducing the pressure with an aspirator. This operation was repeated 13 times to react the metal chloride with NaOH. The water was completely evaporated by heating under reduced pressure of the aspirator. The obtained catalyst was washed with water to remove chlorine atoms and NaOH. It was dried at 150 ° C. for 2 hours in an air atmosphere (the chlorine content was below the detection limit). Thereafter, a ruthenium-palladium co-supported catalyst (2.5 wt% Ru-2.5 wt% Pd / SiO2, hereinafter referred to as “catalyst E”) was prepared by performing gas phase hydrogen reduction at 250 ° C. for 4 hours. The amount of CO adsorbed by catalyst E was 2.4 cm ³ / g (STP), the metal surface area was 183 m ² / g-metal, and the metal dispersion was 45%.

A 200 ml SUS316 autoclave was charged with 0.5 g of catalyst E and 50 g of water. After replacing the gas phase part 3 times with nitrogen 1 MPa, the gas phase part was replaced 3 times with hydrogen 1 MPa to form a hydrogen atmosphere. The mixture was stirred at room temperature for 30 minutes with a magnetic stirring blade in a hydrogen atmosphere. Thereafter, the flange was opened, and 5 g of trimellitic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) and 10 g of water were charged into the autoclave. After replacing the gas phase part 3 times with 1 MPa of nitrogen, the gas phase part was replaced 3 times with 1 MPa of hydrogen. The pressure was increased to 9 MPa with hydrogen, the temperature was raised to 50 ° C. while stirring with an electromagnetic stirring blade, and the reaction was stopped 60 minutes after the start of the temperature increase. When the reaction product is derivatized to a methyl ester form and analyzed by gas chromatography, the conversion of trimellitic acid is 84.3%, and the selectivity for trimellitic acid hydride (1,2,4-cyclohexanetricarboxylic acid) is 96.6. %. The reaction rate constant at 30 minutes from the start of temperature increase was 1.7 hr ⁻¹ .

In Examples 1 to 3, where the catalyst precursor was treated with an organic alkali when preparing the co-supported catalyst, the reaction rate was fast, the conversion rate reached 100% in 60 minutes, and the selectivity of the target product was also high. It was good. On the other hand, in Comparative Example 1 (metal dispersion degree 34%) corresponding to the catalyst disclosed in Patent Document 6, the reaction rate was insufficient. In Comparative Example 2 in which the catalyst precursor was treated with an inorganic alkali, the reaction results were inferior to those of Comparative Example 1.

Claims (3)

A method for producing a catalyst in which ruthenium and palladium are co-supported on a support, wherein ruthenium and palladium are present in the form of particles containing both on the support surface, the metal dispersion is 46% or more, The catalyst precursor is prepared by supporting ruthenium and palladium chloride on a support and then contacting the catalyst precursor with an organic alkali. Further, the catalyst is a fragrance of trimellitic acid, trimesic acid or pyromellitic acid. A method for producing a ruthenium-palladium co-supported catalyst, which is used as a catalyst for hydrogenating a ring. The method for producing a co-supported catalyst according to claim 1, wherein the support comprises one or a combination of two or more selected from the group consisting of activated carbon, alumina, zirconia, ceria, titania and silica. The method for producing a co-supported catalyst according to claim 1, wherein the support is silica.