JP5966244B2 - Hydrogenation catalyst, method for producing the same, and use thereof - Google Patents

Description

  The present invention relates to a catalyst used for hydrogenation of organic compounds. Specifically, the present invention relates to a useful catalyst used for hydrogenation of aldehydes, ketones, carboxylic acids, carboxylic acid esters, aromatic nitro compounds and the like.

  As a useful catalyst used in the hydrogenation reaction, conventionally, a copper / chromium oxide catalyst is widely known as a copper chromite catalyst (see, for example, Non-Patent Document 1).

  As a specific example thereof, gaseous nitrobenzene is hydrogenated using a copper / chromium oxide catalyst under conditions of a reaction temperature of 180 to 370 ° C., a pressure of 0.1 to 0.5 MPa, and a nitrobenzene concentration of 2 to 14% by volume. A method for producing aniline by reduction is known (for example, see Patent Document 1). However, since such a catalyst containing chromium oxide may cause health damage or environmental pollution due to chromium, careful handling is required for its handling, and a great deal of effort is required to treat and recover the used catalyst. And cost was necessary.

  Furthermore, a method for producing an aromatic amine by hydrogenation of an aromatic nitro compound using a modified Raney copper catalyst containing copper, iron and aluminum as basic components has been proposed (for example, see Patent Document 2). However, in general, Raney metal catalysts are prone to decrease in activity due to surface oxidation, so they must be stored in water or in an inert gas atmosphere, and careful handling is required. Moreover, although activity is high, there exists a problem that it is not enough in durability.

  Recently, a molded hydrogenation catalyst made of natural clay minerals such as copper, calcium silicate, and attapulgite has been proposed (see, for example, Patent Document 3). However, although this molded catalyst is excellent in strength and durability, it contains a natural material as a raw material, so that the composition and particle size of the produced catalyst are not reproducible due to variations in its composition and physical properties. Have.

  Moreover, the shaping | molding catalyst which consists of copper, a calcium silicate, and a hydrotalcite is proposed (for example, refer patent document 4). However, since this molded catalyst uses hydrotalcite or petal-like calcium silicate whose composition is controlled, it has an economic problem that it must be relatively expensive.

JP-A-49-231 Japanese Patent Laid-Open No. 9-124562 Japanese National Patent Publication No. 11-507867 JP 2007-289855 A

Catalysis Engineering Lecture 10 “Handbook of Catalysts by Elements” (page 80)

  Unlike the conventional copper / chromium oxide, the present invention does not cause any environmental pollution or health hazard by not containing chromium oxide, and moreover, the activity is equal to or higher than that of the conventional copper / chromium oxide catalyst. An object of the present invention is to provide a catalyst exhibiting selectivity and durability.

As a result of intensive studies, the present inventors have found that the hydrogenation catalyst mainly composed of copper and calcium silicate contains 20 to 60% by weight of copper, and preferably contains 30 to 60% by weight of copper. It has been found that a hydrogenation catalyst having a molar ratio of calcium oxide (CaO) to silicon oxide (SiO ₂ ) in calcium silicate in the range of 0.1 to 0.7 solves the above problem.

In the present invention, the copper oxide is contained in an amount of 30 to 75% by weight, preferably 40 to 75% by weight, and the molar amount of calcium oxide (CaO) with respect to silicon oxide (SiO ₂ ) in calcium silicate. The hydrogenation catalyst of the present invention can be produced by reducing a hydrogenation catalyst precursor having a ratio in the range of 0.1 to 0.7.

  Further, according to the present invention, a compound selected from aldehydes, ketones, carboxylic acids, carboxylic acid esters and aromatic nitro compounds and hydrogen in the temperature range of 100 to 350 ° C. using the hydrogenation catalyst. To produce a hydrogenated compound.

  Hereinafter, the present invention will be described in detail.

That is, the present invention provides a hydrogenation catalyst comprising copper and calcium silicate, wherein the molar ratio of calcium oxide (CaO) to silicon oxide (SiO ₂ ) in calcium silicate is in the range of 0.1 to 0.7. The present invention relates to a hydrogenation catalyst.

  Copper, the hydrogenation catalyst component, reduces the hydrogenation catalyst precursor as copper oxide, hydroxide, carbonate or nitrate that can be easily converted into copper oxide form upon firing, or a mixture of two or more. To be prepared. The hydrogenation catalyst of the present invention contains 20 to 60% by weight of copper, preferably 30 to 60% by weight, and more preferably 30 to 55% by weight. When the copper concentration is less than 20% by weight, the reaction load (raw material feed amount) becomes insufficient in activity, coking increases and the catalyst life is shortened. On the other hand, when the copper concentration exceeds 60% by weight, the copper is loaded. The dispersibility of the copper tends to decrease, and the activity per supported copper tends to decrease. Further, it is preferable that the copper concentration is in the range of 30 to 60% by weight, more preferably 30 to 55% by weight, because improvement of the catalyst life can be expected.

  The concentration of copper in the hydrogenation catalyst is a value calculated by the ICP analysis method described in JIS K0400-52-30 as copper ions.

The molar ratio of calcium oxide (CaO) to silicon oxide (SiO ₂ ) in the calcium silicate used in the present invention is in the range of 0.1 to 0.7, preferably 0.2 to 0.4. is there. When the molar ratio of calcium oxide (CaO) to silicon oxide (SiO ₂ ) in calcium silicate is in the range of 0.1 to 0.7, the copper dispersibility is remarkably increased when the copper is supported. The particle diameter of the copper thus obtained becomes fine particles. As a result, there is an effect that the surface area of copper is increased and the activity of the catalyst is increased. In addition, the acid basicity of the catalyst is modified, and the effect of suppressing carbon deposition on the catalyst surface, so-called coking, is observed. Therefore, it is considered that the activity deterioration due to coking is suppressed and the catalyst life is remarkably increased. Further, it is preferable that the molar ratio of calcium oxide to silicon oxide is in the range of 0.2 to 0.4 because improvement of catalyst life can be expected.

In the present invention, silicon oxide (SiO ₂ ) in calcium silicate is calculated by a weight method analysis method described in JIS K0101, and calcium oxide (CaO) is converted into calcium ion in JIS K0400-52-30. It was calculated by the described ICP analysis method and converted as calcium oxide.

The surface area of the calcium silicate used in the present invention is preferably 100 m ² / g or more, and more preferably 150 m ² / g or more. When the surface area of the calcium silicate is 100 m ² / g or more, copper is highly dispersed and supported on the calcium silicate. Therefore, the particle diameter of copper becomes fine particles. As a result, the surface area of copper is increased, and the effect of increasing the activity of the catalyst is observed. Therefore, it is considered that coking is suppressed and the catalyst life is remarkably prolonged. Further, it is preferable that the surface area of the calcium silicate is 150 m ² / g or more because further improvement of the catalyst life can be expected.

  The surface area of calcium silicate was calculated by the gas adsorption method described in JIS Z8830.

  The calcium silicate used in the present invention may be a natural source or a synthetic source, but is preferably synthesized by controlling the calcium oxide to silicon oxide at a molar ratio of 0.1 to 0.7. Is used.

  More specifically, calcium sources such as quick lime (calcium oxide), slaked lime (calcium hydroxide), calcium chloride, and calcium carbonate that can react with silicon oxide are mixed under atmospheric pressure at room temperature or under warming. Obtain calcium acid. At this time, an alkali such as sodium hydroxide or sodium carbonate may be added to accelerate the reaction. The silicon oxide can be amorphous, crystalline, or a mixture thereof, but is preferably amorphous. The non-crystalline silicon oxide may be produced by either a dry synthesis method or a wet synthesis method, but it may be produced by an inexpensive wet synthesis method, for example, Nipsil “NS-K from Tosoh Silica Corporation. ”(Registered trademark) is commercially available.

  At the time of producing the catalyst of the present invention, at least one or more of copper, which is a hydrogenation catalyst component, or copper oxide, or hydroxide, carbonate or nitrate which can be easily changed into a copper oxide form by firing The means for mixing the copper compound and calcium silicate is not particularly limited, and any means can be used as long as these can be mixed uniformly. For example, when the composition in the appropriate range is charged into a mixing apparatus and dry-mixed or wet-mixed, the resulting mixture is dried and calcined to obtain the precursor powder of the hydrogenation catalyst of the present invention. Can do.

  In addition, an aqueous solution of copper nitrate, copper chloride or the like is added to the aqueous slurry of calcium silicate wet-synthesized from the above-mentioned silicon oxide and calcium oxide, continuously or collectively or dividedly, and an aqueous sodium hydroxide solution, sodium carbonate Neutralize with an aqueous solution, an aqueous solution of sodium hydrogen carbonate, etc., and carry copper on calcium silicate and filter to obtain a catalyst wet cake. The obtained wet cake can be dried to obtain the hydrogenation catalyst precursor powder of the present invention.

  If necessary, flow control agents, pore imparting agents, reinforcing agents, binders such as clay are used as auxiliary agents, and powdered catalysts are extruded or compression molded to form molded bodies of various structures and forms. After being obtained, the molded body of the hydrogenation catalyst precursor can be obtained by firing.

  In the present invention, the hydrogenation catalyst precursor is preferably reduced in the reactor before the intended hydrogenation reaction and activated to form a hydrogenation catalyst. As a method for reducing the hydrogenation catalyst precursor, for example, when hydrogen gas is used as a reducing agent in a gas phase or a liquid phase, the gas phase reduction may be performed at a temperature of 100 to 500 ° C., preferably 150 to 300 ° C. desirable. If the temperature is lower than 100 ° C., the reduction reaction is difficult to proceed. Moreover, since reaction advances stably in the temperature range of 150-300 degreeC, it is preferable. In this case, a hydrogen gas diluted with an inert gas such as nitrogen, helium, or argon may be used.

  The hydrogenation catalyst of the present invention thus obtained is suitably used for a hydrogenation reaction targeting aldehydes, ketones, carboxylic acids, carboxylic acid esters and aromatic nitro compounds.

  Examples of aldehydes that can be hydrogenated to produce alcohol using the catalyst of the present invention include formaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, 2-methylbutyraldehyde, 3-methyl Butyraldehyde, 2,2-dimethylpropionaldehyde, capronaldehyde, 2-methylvaleraldehyde, 3-methylvaleraldehyde, 4-methylvaleraldehyde, 2-ethylbutyraldehyde, 2,2-dimethylbutyraldehyde, 3,3- Examples include dimethylbutyraldehyde, caprylaldehyde, caprinaldehyde, glutardialdehyde. Examples of ketones include acetone, butanone, pentanone, hexanone, cyclohexanone, acetophenone, and the like.

  Carboxylic acids and carboxylic acid esters that can be produced by hydrogenation using the catalyst of the present invention include formic acid, acetic acid, caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, Examples include isostearyl acid, oleic acid, oxalic acid, maleic acid, adipic acid, sebacic acid, cyclohexanecarboxylic acid, benzoic acid, phthalic acid, and esters thereof.

Aromatic nitro compounds that can be produced by hydrogenation using the catalyst of the present invention include nitrobenzene, alkyl-substituted nitrobenzenes, nitronaphthalenes, 4-nitrodiphenyl, nitroanthraquinones, nitro Phenanthros, 2-nitrofuran, 2-nitrothiophene, 3-nitropyridine, 2-nitrodiphenyl ether, 5-nitro-1H-benzotriazole, isomeric dinitrobenzenes, isomeric nitroanilines, p-nitrobenzoic acid Examples include acids, m-nitrobenzoic acid, o-nitrobenzoic acid, isomeric nitrophenols, o-nitrochlorobenzene, m-nitrochlorobenzene, p-nitrochlorobenzene, 3,4-dinitrochlorobenzene. In particular, nitrobenzene is a suitable nitro compound for applying the hydrogenation reaction of the present invention. This hydrogenation of nitrobenzene is effective because it can suppress side reactions and prolong the catalyst life by performing it under a temperature of 100 to 350 ° C. and a pressure of 0.1 to 0.5 MPa. is there. The molar ratio of hydrogen / nitrobenzene is preferably 10 to 20 times, and an inert gas such as nitrogen can be mixed from the viewpoint of removal of reaction heat and catalyst deterioration. The range of 1000 to 2000 h ⁻¹ is suitable for GHSV (raw material gas inflow rate per unit volume).

  The hydrogenation catalyst according to the present invention does not contain harmful chromium as a component, and has excellent activity and selection for hydrogenation reactions such as aldehydes, ketones, carboxylic acids, carboxylic acid esters and aromatic nitro compounds. With high rate and long catalyst life.

A molar ratio of CaO / SiO ₂ of calcium silicate and the estimated catalyst life relationship.

  The present invention will be described in detail by the following examples, but the present invention is not limited by these examples.

Example 1
(Preparation of hydrogenation catalyst precursor)
Add 225 mL of ion-exchanged water to a 2 L glass container, and then add silica powder (Tosoh) so that the molar ratio of calcium oxide to silica (silicon oxide) (CaO / SiO ₂ molar ratio) is 0.25. A silica silicate carrier was prepared by charging 30.0 g of silica (Nipsil “NS-K”) and 7.0 g of quicklime powder (manufactured by Kanto Chemical Co., Ltd., reagent grade 1) and stirring at 25 ° C. for 24 hours. While maintaining the prepared calcium silicate slurry aqueous solution at 25 ° C. with stirring, 382.7 g of 39 wt% aqueous copper nitrate solution (manufactured by Kansai Catalysts Chemical) was added at a constant rate over 3 hours. At that time, the slurry aqueous solution was controlled to pH 6.5 to 7.5 with a 20 wt% sodium carbonate aqueous solution. After completion of the addition of the aqueous copper nitrate solution, the mixture was aged with stirring at 25 ° C. for 2 hours. The precipitate was then filtered and the wet cake was washed with 3 L of ion exchange water.

  The resulting wet cake was dried in air at 110 ° C. overnight, and the dried solid was coarsely ground and calcined at 450 ° C. for 3 hours. After adding 2.0 g of graphite as a lubricant to the obtained fired powder and mixing it, it was molded into a cylindrical shape of 5 mmΦ × 5 mm with a rotary tableting machine. The obtained molded product was fired again at 450 ° C. for 3 hours to obtain a hydrogenation catalyst precursor.

(Nitrobenzene hydrogenation reaction)
The hydrogenation catalyst precursor was crushed with a mortar, and the catalyst was sieved to 2.8 to 1.0 mm particles using 2.8 mm and 1.0 mm sieves. 30 mL of the sieved catalyst particles were charged into a SUS fixed bed reactor, and reduced and activated at 215 ° C. for 24 hours under hydrogen flow. The catalyst performance was evaluated under the conditions of a hydrogen pressure of 0.14 MPa, a reaction temperature of 175 ° C., GHSV 1500 h ⁻¹ , LHSV (feed rate of raw material liquid per unit volume) 0.4 h ⁻¹ , and a hydrogen / nitrobenzene molar ratio of 15. The hydrogenation reaction of nitrobenzene was carried out continuously for 800 hours. The obtained reaction product was analyzed by gas chromatography (device is GC-14A manufactured by Shimadzu Corporation, column is DB170). The aniline selectivity after 800 hours of the reaction was 99.8%. Further, the estimated catalyst life calculated from the moving speed of the maximum temperature position in the catalyst layer during the 800 hours of the reaction was about 17,000 hours.

Copper concentration in Table 1 (wt%), indicating CaO / SiO ₂ molar ratio, aniline selectivity after the reaction 800 hours (%) and the estimated catalyst life (time).

  The copper concentration was quantified by ICP Optima 5300 DV manufactured by PerkinElmer. The surface area of the carrier was measured with Flow Soap II2300 manufactured by Shimadzu Corporation.

Examples 2-5
The same operation as in Example 1 was performed except that the predetermined copper concentration (% by weight) shown in Table 1 and the predetermined CaO / SiO ₂ molar ratio were obtained. Table 1 shows the results of aniline selectivity and estimated catalyst life after 800 hours of reaction.

Example 6
(Preparation of hydrogenation catalyst precursor)
Add 225 mL of ion-exchanged water to a 2 L glass container, and then add silica powder (Tosoh) so that the molar ratio of calcium oxide to silica (silicon oxide) (CaO / SiO ₂ molar ratio) is 0.25. 36.0 g made of silica (Nippil “NS-K”) and 11.1 g slaked lime powder (manufactured by Kanto Chemical Co., Ltd., reagent grade 1) were charged and stirred at 40 ° C. for 6 hours to prepare a calcium silicate carrier. While maintaining the prepared calcium silicate slurry aqueous solution at 40 ° C. with stirring, 305.5 g of 39 wt% aqueous copper nitrate solution (manufactured by Kansai Catalyst Chemical) was added at a constant rate over 4 hours. At that time, the slurry aqueous solution was controlled to pH 6.5 to 7.5 with a 20 wt% sodium carbonate aqueous solution. After completion of the addition of the copper nitrate aqueous solution, the mixture was aged and stirred at 40 ° C. for 2 hours. The precipitate was then filtered and the wet cake was washed with 3 L of ion exchange water.

  The resulting wet cake was dried in air at 110 ° C. overnight. After adding 2.0 g of graphite as a lubricant to the obtained dry powder and mixing, it was molded into a cylindrical shape of 5 mmΦ × 5 mm with a rotary tableting machine. The obtained molded product was fired again at 450 ° C. for 3 hours to obtain a hydrogenation catalyst precursor.

(Nitrobenzene hydrogenation reaction)
The same operation as in Example 1 was performed except that the obtained hydrogenation catalyst precursor was used. Table 1 shows the results of aniline selectivity and estimated catalyst life after 800 hours of reaction.

Examples 7-8
The same operation as in Example 6 was performed except that the predetermined copper concentration (% by weight) shown in Table 1 and the predetermined CaO / SiO ₂ molar ratio were obtained. Table 1 shows the results of aniline selectivity and estimated catalyst life after 800 hours of reaction.

Example 9
Using silica powder (Nippel “CX-200”, manufactured by Tosoh Silica) as the silica component, the predetermined copper concentration (wt%) shown in Table 1 and the predetermined CaO / SiO ₂ molar ratio were obtained. Except for this, the same procedure as in Example 6 was performed. Table 1 shows the results of aniline selectivity and estimated catalyst life after 800 hours of reaction.

Comparative Example 1
This was carried out in the same manner as in Example 6 except that calcium silicate having a surface area of 130 m ² / g (made by Tokuyama, Fluorite) was used to achieve the predetermined copper concentration (weight%) shown in Table 1. . Table 1 shows the results of aniline selectivity and estimated catalyst life after 800 hours of reaction.

Comparative Examples 2 to 4
The same operation as in Example 1 was performed except that the predetermined copper concentration (% by weight) shown in Table 1 and the predetermined CaO / SiO ₂ molar ratio were obtained. Table 1 shows the results of aniline selectivity and estimated catalyst life after 800 hours of reaction.

Comparative Example 5
(Preparation of hydrogenation catalyst precursor)
Into a 2 L glass container, 400 mL of ion-exchanged water is charged, and under stirring, 286 mL of sodium silicate solution No. 3 having a silica content of 6.76 mol / L (manufactured by Kishida Chemical) and an aqueous solution of 0.16 mol / L aluminum sulfate 302 mL (manufactured by Kanto Chemical Co., Inc.) was introduced at a constant rate in 1 hour using a metering pump. The reaction operation was carried out at 25 ° C., and the pH was 4 after completion of the reaction.

  Subsequently, the resulting reaction solution was aged by heating at 95 ° C. for 1 hour.

  After that, suction filtration was performed using a Nutsche, and the wet cake was washed with 500 mL of ion-exchanged water. The obtained wet cake was dried in air at 75 ° C. overnight, and the obtained solid was coarsely pulverized to obtain an aluminum silicate carrier.

  To a 2 L glass container, 400 mL of ion exchange water was added, and then 32 g of the above aluminum silicate support was added and heated to 60 ° C. While maintaining the prepared carrier slurry aqueous solution at 60 ° C. with stirring, 382.7 g of 39 wt% aqueous copper nitrate solution (manufactured by Kanto Chemical) was added at a constant rate over 3 hours. At that time, the slurry aqueous solution was controlled to pH 6.5 to 7.5 with a 20 wt% sodium carbonate aqueous solution. After completion of the addition of the copper nitrate aqueous solution, aging was performed at 60 ° C. for 2 hours. The precipitate was then filtered and the wet cake was washed with 3 L of ion exchange water.

  The resulting wet cake was dried in air at 110 ° C. overnight, and the dried solid was coarsely ground and calcined at 450 ° C. for 3 hours. 5 g of silica sol (manufactured by Nissan Chemical Co., Snowtex 40) was added to the obtained fired powder as a binder, mixed, and then molded into a cylindrical shape of 5 mmΦ × 5 mm with a rotary tableting machine. The obtained molded product was fired again at 450 ° C. for 3 hours to obtain a hydrogenation catalyst precursor.

(Nitrobenzene hydrogenation reaction)
The same operation as in Example 1 was performed except that the obtained hydrogenation catalyst precursor was used. Table 1 shows the results of aniline selectivity and estimated catalyst life after 800 hours of reaction.

Comparative Example 6
(Preparation of hydrogenation catalyst precursor)
Add 1 L of ion-exchanged water to a 2 L glass container, then add 111.2 g of copper nitrate trihydrate (manufactured by Kanto Chemical Co., Ltd., reagent grade), raise the temperature to 80 ° C. with stirring, and add a copper nitrate aqueous solution. Was prepared. Separately, 45 g of sodium hydroxide (manufactured by Kanto Chemical Co., Ltd., reagent grade 1) was added to 0.8 L of ion-exchanged water and dissolved to prepare an aqueous sodium hydroxide solution. While maintaining the copper nitrate aqueous solution at 80 ° C., the sodium hydroxide aqueous solution was added while stirring. After completion of the addition, the mixture was stirred at 80 ° C. for 30 minutes, and then the slurry was cooled to 50 ° C., the precipitate was filtered, and the wet cake was washed with 366 mL of ion-exchanged water.

  Next, 1 L of ion exchange water is added to a 2 L glass container, the above precipitate is added, repulped, and hydrotalcite (Kyowa Chemical Industry) containing 40.2 g of calcium silicate (made by Tokuyama, Florite) and magnesium. (Manufactured by Alkamak) was added and stirred for 1 hour. The slurry was filtered to obtain a wet cake.

  The resulting wet cake was dried in air at 110 ° C. overnight, and the dried solid was coarsely ground. 1.5 g of graphite was added to the obtained dry powder as a lubricant, mixed, and then molded with a press molding machine. This molded product was calcined at 400 ° C. for 6 hours to obtain a hydrogenation catalyst precursor.

(Nitrobenzene hydrogenation reaction)
The same operation as in Example 1 was performed except that the obtained hydrogenation catalyst precursor was used. Table 1 shows the results of aniline selectivity and estimated catalyst life after 800 hours of reaction.

Comparative Example 7
(Preparation of hydrogenation catalyst precursor)
Add 1 L of ion-exchanged water to a 2 L glass container, then add 111.2 g of copper nitrate trihydrate (manufactured by Kanto Chemical Co., Ltd., reagent grade), raise the temperature to 80 ° C. with stirring, and add a copper nitrate aqueous solution. Was prepared. Separately, 45 g of sodium hydroxide (manufactured by Kanto Chemical Co., Ltd., reagent grade 1) was added to 0.8 L of ion-exchanged water and dissolved to prepare an aqueous sodium hydroxide solution. While maintaining the copper nitrate aqueous solution at 80 ° C., the sodium hydroxide aqueous solution was added while stirring. After completion of the addition, the mixture was stirred at 80 ° C. for 30 minutes, and then the slurry was cooled to 50 ° C., the precipitate was filtered, and the wet cake was washed with 366 mL of ion-exchanged water. The obtained wet cake was dried at 110 ° C. overnight to obtain cupric oxide powder.

  To the mortar, 25.7 g of this cupric oxide powder, 9.1 g of calcium hydroxide (manufactured by Kanto Chemical Co., Ltd., reagent grade 1), and 2.1 g of attapulgite clay (manufactured by BASF, Attage 40) were added and kneaded for 5 minutes. Next, 28.9 g of 40 wt% colloidal silica (Nissan Chemical, Snowtex 40) was added and kneaded for 27 minutes. Further, kneading was continued for 34 minutes while adding 9.0 mL of ion-exchanged water.

  The obtained kneaded product was molded by a press molding machine and dried in air at 125 ° C. overnight. The dried molded product was calcined at 600 ° C. for 2 hours to obtain a hydrogenation catalyst precursor.

(Nitrobenzene hydrogenation reaction)
The same operation as in Example 1 was performed except that the obtained hydrogenation catalyst precursor was used. Table 1 shows the results of aniline selectivity and estimated catalyst life after 800 hours of reaction.

FIG. 1 shows the relationship between the CaO / SiO ₂ molar ratio of calcium silicate and the estimated life of the catalyst. As is apparent from FIG. 1, when the hydrogenation catalyst of the present invention is used, the hydrogenation reaction takes a very long time. Can continue over to.

  The hydrogenation catalyst according to the present invention does not contain harmful chromium as a component, and has excellent activity and selection for hydrogenation reactions such as aldehydes, ketones, carboxylic acids, carboxylic acid esters and aromatic nitro compounds. Since it has a high rate and a long catalyst life, it can be used in a wide range of hydrogenation reactions such as aldehydes, ketones, carboxylic acids, carboxylic acid esters and aromatic nitro compounds.

Claims (3)

In the hydrogenation catalyst comprising copper and calcium silicate, the molar ratio of calcium oxide (CaO) to silicon oxide (SiO ₂ ) in calcium silicate is 0.1 to 0. A nitrobenzene hydrogenation catalyst, characterized in that it is in a range of 33 , the surface area of calcium silicate is 150 m ² / g or more, and the concentration of copper is 20 to 60% by weight. It contains 30 to 75% by weight of copper oxide, and the molar ratio of calcium oxide (CaO) to silicon oxide (SiO ₂ ) in calcium silicate is 0.1 to 0.00. The method for producing a nitrobenzene hydrogenation catalyst according to claim 1, wherein the hydrogenation catalyst precursor in the range of 33 is reduced. A method for producing aniline , wherein the nitrobenzene hydrogenation catalyst according to claim 1 is used, and nitrobenzene and hydrogen are contacted in a temperature range of 100 to 350 ° C.

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