WO2016140358A1

WO2016140358A1 - Catalyst composite body

Info

Publication number: WO2016140358A1
Application number: PCT/JP2016/056879
Authority: WO
Inventors: 隆志大橋; 貴正小野; 泰也門口; 善成澤間; 弘尚佐治木
Original assignee: 株式会社クレハ
Priority date: 2015-03-04
Filing date: 2016-03-04
Publication date: 2016-09-09
Also published as: JP2016159256A

Abstract

The purpose of the present invention is to provide a catalyst composite body which has an excellent reducing action. The above-described problem is able to be solved by a catalyst composite body according to the present invention, which is obtained by having a spherical activated carbon support a platinum group metal, and which is characterized by having a bulk density of 0.54 g/cm³ or less. This catalyst composite body according to the present invention is capable of efficiently reducing various compounds.

Description

Catalyst complex

The present invention relates to a catalyst composite in which a platinum group metal is supported on activated carbon and a reduction method using the same. According to the catalyst composite of the present invention, various compounds can be efficiently reduced.

Metal-supported catalysts in which a metal is supported on a carrier are used in a wide range of fields such as automobile exhaust gas purification, chemical synthesis, or fuel cells. Since the metal-supported catalyst is used in a solid phase, it is called a heterogeneous catalyst and catalyzes a reaction of a compound contained in a liquid phase or a gas phase.
As the carrier used for the metal-supported catalyst, activated carbon, ceramics such as alumina, zeolite, or silica gel is mainly used. For example, as a metal-supported catalyst using activated carbon as a carrier, a carboxylic acid hydrogenation catalyst in which ruthenium or the like is supported on zinc chloride activated charcoal (Patent Document 1), it has a pore distribution in the pore diameter range of 20 to 200 nanometers. A hydrocracking catalyst in which a metal is supported on molded activated carbon (Patent Document 2), a catalyst composite in which a metal catalyst is supported on activated carbon produced by extrusion granulation (Patent Document 3), and the like are disclosed. Furthermore, a dehalogenation catalyst in which palladium is supported on granulated charcoal (Patent Document 4) and a catalyst for hydrogenation in which palladium is supported on crushed charcoal (Patent Document 5) are disclosed. In various reaction systems, A metal-supported catalyst using activated carbon as a carrier is used.

JP 2001-157840 A JP 2005-154664 A JP 2005-514191 A JP 2008-183558 A JP 11-137997 A

The present inventors made a catalyst composite in which a platinum group metal is supported on spherical activated carbon, and studied the effect as a reduction catalyst. However, as described in Comparative Examples 1 and 2, the obtained catalyst composite did not exhibit sufficient activity.
Accordingly, an object of the present invention is to provide a catalyst composite exhibiting an excellent reducing action.

As a result of diligent research on a catalyst composite exhibiting an excellent reduction action, the present inventors have surprisingly found that a catalyst composite having a platinum group catalyst supported on a spherical activated carbon exhibiting a specific bulk density has an excellent reduction action. It was found to show.
The present invention is based on these findings.
Therefore, the present invention
[1] A catalyst composite in which a platinum group metal is supported on spherical activated carbon, wherein the bulk density is 0.54 g / cm ³ or less,
[2] The carbon source of the spherical activated carbon is a carbon source selected from the group consisting of petroleum pitch, petroleum tar, coal pitch, coal tar, hot melt resin, and heat infusible resin. The catalyst composite described,
[3] The catalyst composite according to [1] or [2], wherein the supported amount of platinum group metal is 30% by weight or less,
[4] The catalyst composite according to any one of [1] to [3], wherein the bulk density is 0.45 to 0.54 g / cm ³ ;
[5] The catalyst composite according to any one of [1] to [4], wherein the crushing strength is 800 g / piece,
[6] The catalyst composite according to any one of [1] to [5], wherein the sulfur content is 0.05% by weight or less,
[7] The catalyst composite according to any one of [1] to [6], wherein the pore volume having a pore diameter of 100 to 500 nm is 0.03 to 0.10 cm ³ / g,
[8] The catalyst composite according to any one of [1] to [7], wherein the total acidic group is 0.3 mmol / g or more,
[9] The catalyst composite according to any one of [1] to [8] and the amount according to any one of [10] [1] to [9], wherein the amount of pulverization by the carbon dust method is 800 ppm or less A crushed catalyst composite, characterized by crushing the catalyst composite;
[11] A reduction method comprising mixing the catalyst complex according to any one of [1] to [10] with a compound to be reduced,
About.

The catalyst composite of the present invention has an excellent reducing action and can efficiently reduce compounds such as aromatic ketones. Moreover, since the catalyst composite of the present invention is a spherical activated carbon obtained using pitch, tar, or resin as a carbon source, it can be molded into a true sphere. Therefore, it exhibits superior strength (abrasion resistance) as compared with that formed by granulation. Therefore, the lifetime as a catalyst can be extended and long-term utilization is possible. Furthermore, since the catalyst composite of the present invention exhibits high fluidity and excellent operability, it can be used in various reactors. Moreover, according to the catalyst composite of the present invention, since the impurity content, particularly the sulfur content, is low, excellent catalytic activity is exhibited. Furthermore, the catalyst composite of the present invention has a specific pore structure, and it is considered that a further excellent reducing action is exhibited by supporting a platinum group catalyst in this pore structure. Furthermore, the catalyst composite using oxidized spherical activated carbon has an improved reaction rate and exhibits an excellent reducing action.

The catalyst composite obtained in Example 7 was supported on palladium particles at (A) near the surface, (B) 55.4 μm deep, (C) 113.5 μm deep, and (D) 185.2 μm deep. It is the photograph shown. The catalyst composite obtained in Comparative Example 5 was supported on palladium particles at (A) near the surface, (B) at a depth of 60.8 μm, (C) at a depth of 110.2 μm, and (D) at a depth of 187.6 μm. It is the photograph shown. FIG. 3 is a graph showing the pore volume distribution of the spherical activated carbons produced in Examples 1 to 3 and Comparative Examples 1 and 2.

[1] Catalyst Composite The catalyst composite of the present invention is a catalyst composite in which a platinum group metal is supported on spherical activated carbon, and has a bulk density of 0.54 g / cm ³ or less.

"The bulk density"
The bulk density of the catalyst composite of the present invention is not particularly limited as long as it is 0.54 g / cm ³ or less. However, the bulk limit of the density is preferably at 0.53 g / cm ³ or less, more preferably 0.52 g / cm ³ or less, further preferably 0.51 g / cm ³ or less. When the true density is 0.54 g / cm ³ or less, the diffusion rate of the metal is increased in supporting the platinum group metal, and thus the platinum group metal is uniformly supported on the spherical activated carbon. Also in the catalytic reaction, the diffusion rate of the compound to be catalyzed to the platinum group metal is increased, thus increasing the rate of the catalytic reaction. That is, excellent catalytic action can be shown in the reduction reaction. The lower limit of the bulk density is not particularly limited, but is preferably 0.35 g / cm ³ or more, more preferably 0.40 g / cm ³ or more, and further preferably 0.43 g / cm ^3. Or more, and most preferably 0.44 g / cm ³ or more. If the bulk density is too small, the strength of the catalyst composite is reduced, and therefore fine powder may be generated during the catalytic reaction.

"Specific surface area"
The specific surface area of the catalyst composite of the present invention is not particularly limited, but is preferably 500 to 2500 m ² / g, more preferably 1000 to 2200 m ² / g, and still more preferably 1300 to 2000 m ^2. / G. When the specific surface area is less than 500 m ² / g, the adsorption point of the active metal is reduced and the catalytic activity is lowered.

<< pore volume >>
The total pore volume of the catalyst composite of the present invention is not limited, but is preferably 0.250 to 1.000 cm ³ / g. The lower limit of the total pore volume is more preferably 0.300 cm ³ / g or more, further preferably 0.350 cm ³ / g or more, and most preferably 0.400 cm ³ / g or more. The upper limit of the total pore volume is more preferably 0.950 cm ³ / g or less, still more preferably 0.900 cm ³ / g or less, and most preferably 0.850 cm ³ / g or less.
The pore volume of the catalyst composite of the present invention having a pore diameter of 10 nm or less is not limited, but is preferably 0.100 to 0.550 cm ³ / g. The lower limit of the pore volume with a pore diameter of 10 nm or less is more preferably 0.150 cm ³ / g or more, still more preferably 0.180 cm ³ / g or more, and most preferably 0.200 cm ³ / g or more. is there. The upper limit of the pore volume having a pore diameter of 10 nm or less is more preferably 0.500 cm ³ / g or less, still more preferably 0.450 cm ³ / g or less, and most preferably 0.400 cm ³ / g or less. is there.
The pore volume of the pore diameter of 10 to 100 nm of the catalyst composite of the present invention is not limited, but is preferably 0.060 to 0.350 cm ³ / g. The lower limit of the pore volume having a pore diameter of 10 to 100 nm is more preferably 0.070 cm ³ / g or more, still more preferably 0.080 cm ³ / g or more, and most preferably 0.090 cm ³ / g or more. It is. The upper limit of the pore volume with a pore diameter of 10 to 100 nm is more preferably 0.320 cm ³ / g or less, still more preferably 0.290 cm ³ / g or less, and most preferably 0.260 cm ³ / g or less. It is.
The pore volume of the pore diameter of 100 to 500 nm of the catalyst composite of the present invention is not limited, but is preferably 0.030 to 0.100 cm ³ / g. The lower limit of the pore volume of pores having a pore diameter of 100 ~ 500 nm is more preferably 0.033 cm ³ / g or more, further preferably 0.035cm ³ / g or more, most preferably 0.038 cm ³ / g or more It is. The upper limit of the pore volume with a pore diameter of 100 to 500 nm is more preferably 0.085 cm ³ / g or less, still more preferably 0.070 cm ³ / g or less, and most preferably 0.060 cm ³ / g or less. It is.

The ratio (a / d) of the pore volume (a) having a pore diameter of 10 nm or less to the total pore volume (d) of the catalyst composite of the present invention is not limited, but preferably 43 to 65. %. The lower limit is more preferably 45% or more, and the upper limit is more preferably 60% or less.
The ratio (b / d) of the pore volume (b) having a pore diameter of 10 to 100 nm to the total pore volume (d) of the catalyst composite of the present invention is not limited, but preferably 15 to 45%. The lower limit is more preferably 20% or more, and the upper limit is more preferably 35% or less.
The ratio (c / d) of the pore volume (c) having a pore diameter of 100 to 500 nm to the total pore volume (d) of the catalyst composite of the present invention is not limited, but preferably 2 to 20%. The lower limit is more preferably 3% or more, and the upper limit is more preferably 15% or less.
When the pore volume of the catalyst composite of the present invention is in the above range, the diffusion rate of the metal is increased in supporting the platinum group metal, and therefore the platinum group metal is uniformly supported on the spherical activated carbon. Also in the catalytic reaction, the diffusion rate of the compound to be catalyzed to the platinum group metal is increased, thus increasing the rate of the catalytic reaction. That is, excellent catalytic action can be shown in the reduction reaction.
Further, although not limited, the pore volume having a pore diameter of 2 to 200 nm with respect to the total pore volume of the catalyst composite of the present invention is preferably 30% or less or less than 30%. Furthermore, the pore volume having a pore diameter of 20 nm or more with respect to the total pore volume of the catalyst composite of the present invention is preferably 40% or less, or less than 40%. Furthermore, the pore volume of the pore diameter of 2 to 20 nm of the catalyst composite of the present invention is preferably 0.5 cm ³ / g or less, or less than 0.5 cm ³ / g.

《Average particle size》
The average particle size of the catalyst composite of the present invention is not particularly limited, but is preferably 0.02 to 2 mm, more preferably 0.03 to 1.5 mm, and still more preferably 0.05. ~ 1 mm. The range of the particle size (diameter) of the catalyst composite is not limited, but is preferably 0.01 to 3 mm, more preferably 0.02 to 2.5 mm, and still more preferably 0. 0.03 to 2 mm. When the average particle size and the particle size range are within the above ranges, good operability is ensured.

《Crushing power》
The crushing strength of the catalyst composite of the present invention is not particularly limited, but is preferably 500 g / piece or more, more preferably 600 g / piece or more, further preferably 700 g / piece or more, and most preferably 800 g / piece or more. is there. Although an upper limit is not specifically limited, For example, about 1300 g / piece or more is enough. When the crushing strength is less than 500 g / piece, the strength of the catalyst composite is insufficient, and fine powder may be generated during the catalytic reaction.

《Sulfur content》
The spherical activated carbon used in the present invention usually has a small content of impurities contained in the activated carbon. In particular, since the sulfur content is small, it is considered that the catalytic activity is excellent. The sulfur content of the catalyst composite of the present invention is not particularly limited, but is preferably 0.05% by weight or less, more preferably 0.04% by weight, still more preferably 0.03% by weight. %.

《Carbon dust》
The spherical activated carbon used in the catalyst composite of the present invention is obtained by melting a carbon source such as petroleum pitch and molding it into a spherical shape, or emulsion polymerization, bulk polymerization, or solution of a resin such as a thermosetting resin or a thermoplastic resin. It can be obtained by forming a spherical polymer by polymerization or the like. That is, it is not a spherical granulated coal produced by granulating powdered or particulate activated carbon using a binder. Spherical activated carbon used in the present invention and granulated coal can be distinguished by the amount of pulverization measured by the carbon dust method.
The pulverization amount of the catalyst composite of the present invention by the carbon dust method is not limited, but is preferably 800 ppm or less, more preferably 750 ppm or less, still more preferably 700 ppm or less, and still more preferably. 650 ppm or less, and most preferably 600 ppm or less. When the pulverization amount is 800 ppm or less, the catalyst composite of the present invention has high strength and excellent wear resistance.

《Totally acidic group》
Even if the spherical activated carbon used for the catalyst composite of the present invention has few acidic groups, it can support palladium and show the effect of the present invention. However, by using the spherical activated carbon whose total acidic groups are increased by oxidation, the catalyst composite of the present invention can exhibit a further excellent reducing action. In this case, the total acidic group of the catalyst composite of the present invention is preferably 0.1 mmol / g or more, more preferably 0.2 mmol / g or more, and further preferably 0.03 mmol / g or more.

<Crushed catalyst composite>
The pulverized catalyst composite of the present invention can be obtained by pulverizing the catalyst composite. Grinding increases contact between the compound of interest and the platinum group metal. Therefore, the reaction rate can be improved and the reaction time can be shortened.

The catalyst composite can be pulverized according to a known pulverization method. The pulverizer used for pulverization is not particularly limited, and for example, a jet mill, a rod mill, a vibration ball mill, or a hammer mill can be used.
The average particle size of the pulverized catalyst composite of the present invention is not particularly limited as long as the effect is obtained, but is preferably 0.01 to 100 μm, more preferably 0.05 to 50 μm, More preferably, it is 0.1 to 30 μm.
The true density and sulfur content of the pulverized catalyst composite of the present invention are the same as the catalyst composite before pulverization.

《Spherical activated carbon》
The catalyst composite of the present invention uses spherical activated carbon as a carrier. The spherical activated carbon used in the present invention is not granulated charcoal produced by granulating powdered or particulate activated carbon with a binder. Specifically, it can be obtained by melting a carbon source such as petroleum pitch and forming it into a spherical shape. Moreover, it can obtain by making resin, such as a thermosetting resin or a thermoplastic resin, into a spherical polymer by emulsion polymerization, block polymerization, or solution polymerization. The spherical activated carbon used in the present invention has higher strength and less generation of fine powder compared to granulated activated carbon or powdered activated carbon. Therefore, a catalyst composite having excellent wear resistance can be obtained by using the spherical activated carbon.

Examples of the carbon source of the spherical activated carbon include tar, pitch, heat-meltable resin, and heat-infusible resin. The catalyst composite of the present invention can exhibit high strength and excellent wear resistance by using the carbon source.
As tar or pitch, petroleum-based tar or pitch by-produced during ethylene production, coal tar produced during coal dry distillation, heavy component or pitch obtained by distilling off low boiling components of coal tar, tar obtained by coal liquefaction And pitch. Two or more of these tars or pitches may be mixed and used.
The heat-meltable resin is a resin that melts when heat is applied, and examples thereof include a thermoplastic resin. Thermoplastic resins include cross-linked vinyl resin, ketone resin, polyvinyl alcohol, polyethylene terephthalate, polyacetal, polyacrylonitrile, styrene / divinylbenzene copolymer, polyimide, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, polyarylate, polysulfone, polyphenylene. Mention may be made of sulfides, polyimide resins, fluororesins, polyamideimides, amide resins (for example nylon resins or aramid resins) or polyether ether ketones.
Tar, pitch, or heat-meltable resin is infusible by infusibilization treatment (oxidation treatment) without melting even when heat is applied. By performing the infusibilization treatment, heat treatment can be performed while maintaining the spherical shape.

The heat infusible resin is a resin that does not melt even when heat is applied, and spherical activated carbon can be produced without oxidation treatment (infusibilization treatment). For example, a thermosetting resin can be mentioned as a thermofusible resin. Examples of the thermosetting resin include epoxy resin, urethane resin, urea resin, diallyl phthalate resin, polyester resin, silicon resin, furan resin, phenol resin, melamine resin, and amino resin. An ion exchange resin can also be used as the thermosetting resin. An ion exchange resin is generally composed of a copolymer of divinylbenzene and styrene, acrylonitrile, acrylic acid, or methacrylic acid (that is, a thermosetting resin), and is basically a copolymer having a three-dimensional network skeleton. It has a structure in which an ion exchange group is bonded to a polymer matrix. Depending on the type of ion exchange group, the ion exchange resin is a strongly acidic ion exchange resin having a sulfonic acid group, a weak acid ion exchange resin having a carboxylic acid group or a sulfonic acid group, and a strong basic ion exchange having a quaternary ammonium salt. Resins, broadly divided into weakly basic ion exchange resins having primary or tertiary amines, and other special resins include so-called hybrid ion exchange resins having both acid and base ion exchange groups. it can. Furthermore, it is also possible to use an ion exchange resin produced by adding a functional group to the crosslinked vinyl resin. The cross-linked vinyl resin is a heat-meltable resin, but is considered to obtain a function of a thermosetting resin that is cured by heating by a functional group imparting treatment or an introduced functional group.

When using the tar, pitch, or hot-melt resin as a carbon source, an infusibilization treatment is performed. The method of infusibilization treatment is not particularly limited, and can be performed using, for example, an oxidizing agent. The oxidizing agent is not particularly limited, but as the gas, O ₂ , O ₃ , SO ₃ , NO ₂ , a mixed gas obtained by diluting these with air, nitrogen or the like, or an oxidizing gas such as air is used. Can do. As the liquid, an oxidizing liquid such as sulfuric acid, nitric acid, or hydrogen peroxide, or a mixture thereof can be used. The oxidation temperature is not particularly limited, but is preferably 120 to 400 ° C, and more preferably 150 to 350 ° C. If the temperature is lower than 120 ° C., a sufficient crosslinked structure cannot be formed and the particles are fused in the heat treatment step. On the other hand, when the temperature exceeds 400 ° C., the decomposition reaction is more than the crosslinking reaction, and the yield of the obtained carbon material is lowered.
Moreover, a crosslinking agent can be used as an infusible treatment. In the case of using a crosslinking agent, a crosslinking agent is added to petroleum tar or pitch, coal tar or pitch, and the mixture is heated and mixed to proceed a crosslinking reaction to obtain a carbon precursor. For example, as the crosslinking agent, polyfunctional vinyl monomers such as divinylbenzene, trivinylbenzene, diallyl phthalate, ethylene glycol dimethacrylate, or N, N-methylenebisacrylamide that undergo a crosslinking reaction by radical reaction can be used. The crosslinking reaction with the polyfunctional vinyl monomer is started by adding a radical initiator. As radical initiators, α, α ′ azobisisobutyronitrile (AIBN), benzoyl peroxide (BPO), lauroyl peroxide, cumene hydroperoxide, dicumyl peroxide, 1-butyl hydroperoxide, or hydrogen peroxide Etc. can be used.

When using a petroleum-based or coal-based pitch and proceeding with a crosslinking reaction by treatment with an oxidizing agent such as air, the carbon precursor can be obtained by the following method, although not limited thereto. That is, to a petroleum-based or coal-based pitch or the like, a bicyclic to tricyclic aromatic compound having a boiling point of 200 ° C. or higher or a mixture thereof is added as an additive, heated and mixed, and then molded to obtain a pitch molded body. Next, the solvent having a low solubility with respect to the pitch and a high solubility with respect to the additive is extracted and removed from the pitch molded body to form a porous pitch, and then oxidized with an oxidizing agent. A carbon precursor is obtained. The purpose of the aromatic additive is to extract and remove the additive from the molded pitch molded body to make the molded body porous, to facilitate crosslinking treatment by oxidation, and to obtain a carbonaceous material obtained after carbonization. To make it porous. Such additives can be selected from one or a mixture of two or more such as naphthalene, methylnaphthalene, phenylnaphthalene, benzylnaphthalene, methylanthracene, phenanthrene, or biphenyl. The amount added to the pitch is preferably in the range of 30 to 70 parts by weight with respect to 100 parts by weight of the pitch. The pitch and additive are mixed in a molten state by heating in order to achieve uniform mixing. The mixture of pitch and additive is preferably formed into particles having a particle size of 1 mm or less so that the additive can be easily extracted from the mixture. Molding may be performed in a molten state, or may be performed by pulverizing the mixture after cooling. Solvents for extracting and removing the additive from the mixture of pitch and additive include aliphatic hydrocarbons such as butane, pentane, hexane, or heptane, mixtures mainly composed of aliphatic hydrocarbons such as naphtha or kerosene, methanol, Aliphatic alcohols such as ethanol, propanol or butanol are preferred. By extracting the additive from the pitch and additive mixture molded body with such a solvent, the additive can be removed from the molded body while maintaining the shape of the molded body. At this time, it is presumed that a through hole for the additive is formed in the molded body, and a pitch molded body having uniform porosity is obtained.

As the heat-meltable resin and the heat-infusible resin, a spherical polymer obtained by emulsion polymerization, bulk polymerization, or solution polymerization can be used as a solid carbon precursor, but a spherical polymer obtained by suspension polymerization is preferable. . As described above, the spherical polymer obtained from the heat-meltable resin can be infusibilized, and then activated to prepare spherical activated carbon. Since the spherical polymer obtained from the heat infusible resin is not melted by heating, it can be activated as it is to obtain spherical activated carbon.

The spherical activated carbon used for the catalyst composite of the present invention is not limited, but preferably has an appropriate amount of all acidic groups. The total amount of acidic groups can be adjusted by oxidation treatment. The oxidation treatment method is not particularly limited, but for example, 300 to 800 ° C. (preferably in an atmosphere having an oxygen content of 0.1 to 50 vol% (preferably 1 to 30 vol%, particularly preferably 3 to 20 vol%). Can be performed by heat treatment at a temperature of 320 to 600 ° C. By this oxidation treatment, an acid point is added to the surface of the spherical activated carbon, whereby the reducing action of the resulting catalyst complex can be improved.

The physical properties of spherical activated carbon are basically the same as those of the catalyst composite of the present invention.

《Platinum group metal》
The catalyst composite of the present invention uses a platinum group metal as a catalyst. Examples of platinum group metals include ruthenium, rhodium, palladium, osmium, iridium, or platinum. The catalyst composite of the present invention may carry these platinum group metals alone or in combination.
The amount of platinum group metal supported in the catalyst composite of the present invention is not particularly limited as long as the effects of the present invention are obtained, but is preferably 0.1 to 30% by weight, more preferably 0. .2 to 20% by weight, more preferably 0.3 to 10% by weight.

<Manufacture of catalyst composite>
The catalyst composite of the present invention can be produced according to a known supported catalyst production method such as an immersion method, an ion exchange method, or an impregnation method, except that the spherical activated carbon having the physical properties described above is used.
For example, the dipping method can be performed as follows. A compound containing a platinum group metal to be supported (platinum group metal compound) is dissolved in a solvent such as water or an organic solvent to prepare a metal compound solution. Spherical activated carbon is immersed in this solution to carry platinum metal.
As the platinum group metal compound, for example, a mineral acid salt (for example, nitrate, sulfate, or hydrochloride), an organic acid salt (for example, acetate), a hydroxide, an oxide, or an organic metal compound can be used. More specifically, as the platinum group metal compound, palladium nitrate, iridium nitrate, rhodium nitrate, tetraammine palladium nitrate, pentaammine aquadium nitrate, hexaammine iridium hydroxide, chloropalladium acid, chloroiridate, or rhodium chloride Etc.) can be used. These platinum group metal compounds are often water-soluble and can be used alone or in combination of two or more.

The spherical activated carbon carrying a platinum group metal compound can be dried and used as a catalyst. Drying can be usually performed at a temperature of less than 100 ° C. under reduced pressure or by circulating a dry gas such as nitrogen or air. The dried supported catalyst may be used as a catalyst after calcination and reduction.

<< Mechanism of the Present Invention >>
The reason why the reduction effect of the catalyst composite of the present invention is excellent has not been completely clarified, but is considered as follows. However, the present invention is not limited by the following description.
The spherical activated carbon used in the catalyst composite of the present invention has a specific bulk density or a specific pore structure. Since the spherical activated carbon has a specific bulk density or a specific pore structure, palladium is uniformly diffused into the pores of the spherical activated carbon and the palladium particles are uniformly supported in the process of producing the catalyst composite. It is thought that. In addition, even during the reduction reaction using the catalyst complex, the compound to be reduced diffuses uniformly into the pores of the spherical activated carbon due to the specific bulk density or the specific pore structure, and the reaction with the palladium particles takes a short time. It is thought that it progresses with.

[2] Reduction Method The catalyst complex of the present invention can be used in a compound reduction method. The reduction reaction that can be used in the catalyst composite of the present invention is not particularly limited as long as it is a reduction reaction in which a platinum group metal can be used as a catalyst. For example, triple bond reduction, aromatic ketone A reduction reaction such as reduction, reduction of a nitro group, or coupling reaction can be mentioned.

《Reduction reaction》
As the reduction reaction of the triple bond, for example, as shown in the following chemical formula (1), a reaction of reducing diphenylacetylene to 1,2-diphenylethylene and 1,2-diphenylethane by the catalyst complex of the present invention is performed. Can be mentioned.

Examples of the reduction reaction of the aromatic ketone include a reaction in which benzophenone is reduced to diphenylmethanol and diphenylmethane by the catalyst complex of the present invention as shown in the following chemical formula (2).

Examples of the reduction reaction of the nitro group include a reaction in which 4-methoxy 1-nitrobenzene is reduced to 4-methoxy 1-aminobenzene as shown in the following chemical formula (3).

Examples of the reduction reaction further include a reaction represented by the following chemical formula (4).

Examples of the coupling reaction include the Suzuki-Miyaura reaction as shown in the following chemical formula (5).

The reaction temperature of the reduction reaction can be appropriately determined depending on the type and atmosphere of the reduction reaction. For example, the reaction can be carried out at 800 ° C. or lower in a nitrogen atmosphere and 500 ° C. or lower in an oxygen atmosphere, but those skilled in the art can appropriately select the reaction temperature according to the common general technical knowledge of the field to which the present invention belongs. Further, the reaction time of the reduction reaction is not particularly limited, but the reaction is completed in a relatively short time because the catalyst complex of the present invention has a high reaction rate. Although it is not limited, the reaction rate can be improved by using a relatively large amount of a catalyst complex having a small amount of platinum group metal supported for reaction.

Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.

The physical property values of the carbonaceous material for non-aqueous electrolyte secondary batteries of the present invention (“specific surface area”, “true density by butanol method”, “average particle diameter by laser diffraction method”, “pore volume by mercury intrusion method) ”,“ Crushing strength ”,“ carbon dust ”,“ total acid group ”and“ sulfur content ”), the physical property values described in this specification including the examples are as follows: This is based on the value obtained by the above method.

"Specific surface area"
The specific surface area was measured according to the method defined in JIS Z8830. The outline is described below.
Using an approximate expression derived from equation _{BET v m = 1 / (v} (1-x)) at the liquid nitrogen temperature, determine the _{v m} by 1-point method by nitrogen adsorption (relative pressure x = 0.2) The specific surface area of the sample was calculated by the following formula: Specific surface area = 4.35 × v _m (m ² / g)
(Here, v _m is the amount of adsorption (cm ³ / g) required to form a monomolecular layer on the sample surface, v is the amount of adsorption actually measured (cm ³ / g), and x is the relative pressure.)
Specifically, using a “Flow Sorb II2300” manufactured by MICROMERITICS, the amount of nitrogen adsorbed on the carbonaceous material at the liquid nitrogen temperature was measured as follows.
The sample tube is filled with a carbon material, and the sample tube is cooled to −196 ° C. while flowing a helium gas containing nitrogen gas at a concentration of 20 mol%, and nitrogen is adsorbed on the carbon material. The test tube is then returned to room temperature. At this time, the amount of nitrogen desorbed from the sample was measured with a thermal conductivity detector, and the amount of adsorbed gas v was obtained.

《True density by butanol method》
In accordance with the method defined in JIS R7212, measurement was performed using butanol. The outline is described below. In addition, both the carbonaceous material obtained by heat-processing a carbonaceous precursor at 1100 degreeC, and the carbonaceous material of this invention were measured with the same measuring method.
The mass (m ₁ ) of the specific gravity bottle with a side tube having an internal volume of about 40 cm ³ is accurately measured. Next, the sample is put flat on the bottom so as to have a thickness of about 10 mm, and then its mass (m ₂ ) is accurately measured. Gently add 1-butanol to this to a depth of about 20 mm from the bottom. Next, light vibration is applied to the specific gravity bottle, and it is confirmed that large bubbles are not generated. Then, the bottle is put in a vacuum desiccator and gradually exhausted to 2.0 to 2.7 kPa. Keep at that pressure for 20 minutes or more, take out after bubble generation stops, fill with 1-butanol, plug and immerse in a constant temperature water bath (adjusted to 30 ± 0.03 ° C) for 15 minutes or more. Adjust the liquid level of 1-butanol to the marked line. Next, this is taken out, the outside is well wiped off and cooled to room temperature, and then the mass (m ₄ ) is accurately measured. Next, the same specific gravity bottle is filled with only 1-butanol, immersed in a constant temperature water bath in the same manner as described above, and after aligning the marked lines, the mass (m ₃ ) is measured. Moreover, distilled water excluding the gas that has been boiled and dissolved immediately before use is placed in a specific gravity bottle, immersed in a constant temperature water bath as before, and the mass (m ₅ ) is measured after aligning the marked lines. The true density (ρ _Bt ) is calculated by the following formula.

(Where d is the specific gravity of water at 30 ° C. (0.9946))

《Average particle size》
Three drops of a dispersing agent (cationic surfactant “SN Wet 366” (manufactured by San Nopco)) are added to about 0.1 g of the sample, and the sample is made to conform to the dispersing agent. Next, after adding 30 cm ³ of pure water and dispersing with an ultrasonic cleaner for about 2 minutes, a particle size distribution measuring device (“SALD-3000J” manufactured by Shimadzu Corporation) has a particle size in the range of 0.05 to 3000 μm. The particle size distribution was determined.
From the obtained particle size distribution, the average particle size D _v50 (μm) was _{defined as the} particle size with a cumulative volume of 50%.

(3) Pore volume by mercury porosimetry The pore volume can be measured using a mercury porosimeter (for example, “AUTOPORE 9200” manufactured by MICROMERITICS). Spherical activated carbon as a sample is put in a sample container and deaerated at a pressure of 2.67 Pa or less for 30 minutes. Next, mercury is introduced into the sample container and gradually pressurized to press the mercury into the pores of the spherical activated carbon sample (maximum pressure = 414 MPa). From the relationship between the pressure at this time and the amount of mercury injected, the pore volume distribution of the spherical activated carbon sample is measured using the following equations.
Specifically, the volume of mercury injected into the spherical activated carbon sample from a pressure corresponding to a pore diameter of 15 μm (0.07 MPa) to a maximum pressure (414 MPa: corresponding to a pore diameter of 3 nm) is measured. The pore diameter is calculated when mercury is pressed into a cylindrical pore having a diameter (D) at a pressure (P), where the surface tension of mercury is “γ” and the contact angle between the mercury and the pore wall is “ θ ”, from the balance between the surface tension and the pressure acting on the pore cross section, the following formula:
−πDγcos θ = π (D / 2) ² · P
Holds. Accordingly, D = (− 4γcos θ) / P
It becomes.
In this specification, the surface tension of mercury is 484 dyne / cm, the contact angle between mercury and carbon is 130 degrees, the pressure P is MPa, and the pore diameter D is expressed in μm.
D = 1.27 / P
To obtain the relationship between the pressure P and the pore diameter D. The pore volume in the range of the pore diameter of 20 to 15000 nm in the present invention corresponds to the volume of mercury that is injected from a mercury intrusion pressure of 0.07 MPa to 63.5 MPa. The pore volume distribution is shown in FIG.

《Crushing power》
Using a powder hardness tester (for example, a simple powder hardness tester manufactured by Tsutsui Rika Kikai Co., Ltd.), the force required to crush one spherical activated carbon sample is measured. Specifically, one spherical activated carbon sample is sandwiched between two plates (sample particles are fixed with double-sided tape if necessary), and the force at which the sample particles break is measured while applying a load. The measurement was performed 30 times, and the average value was taken as the crushing strength of the sample.

《Sulfur content》
The sulfur content was measured in accordance with the method defined in JIS K0127. The outline is described below.
The sample was combusted and decomposed by the quartz tube combustion method, and the generated gas was absorbed in the absorption liquid, and quantified by the ion chromatography method.

(Measurement of each element content)
In order to measure the potassium element content and the content of each element such as iron, a carbon sample containing each element group element such as a predetermined potassium element and iron is prepared in advance, and using a fluorescent X-ray analyzer, potassium Kα ray A calibration curve was created for the relationship between the strength of each element and the potassium content, and the relationship between the intensity of each element Kα ray such as iron and the content of each element such as iron. Subsequently, the intensity | strength of each element K alpha rays, such as potassium K alpha ray and iron in a fluorescent X ray analysis, was measured about the sample, and each element content, such as potassium content and iron, was calculated | required from the analytical curve created previously. Table 3 shows the particle size, specific surface area, and metal content. X-ray fluorescence analysis was performed using LAB CENTER XRF-1700 manufactured by Shimadzu Corporation under the following conditions. Using the upper irradiation system holder, the sample measurement area was within the circumference of 20 mm in diameter. The sample to be measured was placed by placing 0.5 g of the sample to be measured in a polyethylene container having an inner diameter of 25 mm, pressing the back with a plankton net, and covering the measurement surface with a polypropylene film for measurement. The X-ray source was set to 40 kV and 60 mA. For potassium, LiF (200) was used as the spectroscopic crystal and a gas flow proportional coefficient tube was used as the detector, and 2θ was measured in the range of 90 to 140 ° at a scanning speed of 8 ° / min. For iron, LiF (200) was used for the spectroscopic crystal, and a scintillation counter was used for the detector, and 2θ was measured in the range of 56 to 60 ° at a scanning speed of 8 ° / min.
Table 3 shows the content of impurities.

(All acidic groups)
Add 1 g of spherical activated carbon sample or surface modified spherical activated carbon sample crushed to 200 mesh or less into 50 cm ^{3 of} 0.05 normal NaOH solution, shake for 24 hours, filter off the spherical activated carbon sample, and neutralize The consumption of NaOH determined by titration was measured.

(Measurement of carbon dust)
A sample (5 g) and pure water (100 cm ³ ) were added to a 100 cm ³ Erlenmeyer flask, and the mixture was shaken with an ultrasonic cleaner for 3 minutes. The supernatant was collected and suction filtered through a membrane filter having an opening of 1 μm. Shaking and filtration were repeated three times, the filtrate on the filter was dried, the weight was measured, and the amount of carbon dust was measured. The results are shown in Table 4.

Example 1
(1) Production of spherical activated carbon Petroleum pitch (softening point = 210 ° C., quinoline insoluble content = 1 wt% or less, H / C atomic ratio = 0.63) 68 kg and naphthalene 32 kg with stirring blades The mixture was charged into a 300 L pressure vessel and melt-mixed at 180 ° C., then cooled to 80 to 90 ° C. and extruded to obtain a string-like molded body. Next, the string-like molded body was crushed so that the ratio of diameter to length was about 1-2. To this crushed material, 120 kg of 0.23% by weight aqueous solution of polyvinyl alcohol (saponification degree = 88%) was added and dispersed by stirring at 95 ° C. at a speed of 350 rpm, and then rapidly cooled to solidify the dispersed particles. A spherical pitch molded body was obtained.
Further, filtration was performed to remove moisture, and naphthalene in the spherical pitch molded body was extracted and removed with n-hexane about 6 times the weight of the spherical pitch molded body. Subsequently, oxidation treatment was performed in air at 260 ° C. for 1 hour to obtain an infusible porous spherical oxidation pitch.
Next, in the nitrogen gas containing the obtained infusible porous spherical oxide pitch and water vapor of 50 vol%, a pre-activation treatment is carried out until the bulk density becomes 0.6 g / cm ³ or more, and the spherical activated carbon precursor. Got. It can be confirmed that the bulk density is 0.6 g / cm ³ or more by taking a part of the spherical activated carbon precursor from the pre-baking furnace and measuring the bulk density during the pre-activation process.
Next, the spherical activated carbon precursor was calcined at 1450 ° C. for 4 hours in a nitrogen gas atmosphere. Furthermore, activation treatment was performed in a nitrogen gas at 850 ° C. containing 50 vol% and 0.5 vol% of water vapor until the bulk density became 0.383 g / cm ³ , and spherical activated carbon 1 was obtained.

(2) Loading of palladium 527 mg (2.35 mmol) of palladium acetate was dissolved in 50 cm ³ of methanol in a flask filled with argon as an inert gas. To this solution, 5 g of spherical activated carbon 1 was added so that the content of metal palladium was 5% by mass, and stirring was continued at room temperature under an argon atmosphere until the supernatant became transparent. The resulting black powder was filtered with suction, and then washed in the order of methanol (twice 30 cm ³ each time) and water (twice 30 cm ³ times). Subsequently, it dried at room temperature under reduced pressure in the desiccator, and the catalyst composite 1 was obtained. The physical properties of the resulting catalyst composite 1 are shown in Tables 1 and 2.

Example 2
In this example, a catalyst composite was produced using spherical activated carbon having a bulk density of 0.429 g / cm ³ .
Except that the activation treatment was performed until the bulk density of the spherical activated carbon reached 0.429 g / cm ³ , the operation of Example 1 was repeated to obtain a catalyst composite 2.

Example 3
In this example, a catalyst composite was produced using spherical activated carbon having a bulk density of 0.473 g / cm ³ .
Except that the activation treatment was performed until the bulk density of the spherical activated carbon reached 0.473 g / cm ³ , the operation of Example 1 was repeated to obtain a catalyst composite 3.

Example 4
In this example, the catalyst composite 1 obtained in Example 1 was pulverized to produce a pulverized catalyst composite. The pulverization was performed for 2 minutes using a rod mill, and pulverized to an average particle size of 7.5 μm to obtain catalyst composite 4.

Example 5
In this example, the catalyst composite 2 obtained in Example 2 was pulverized to produce a pulverized catalyst composite.
Except that the catalyst composite 2 was used, the operation of Example 4 was repeated to obtain a catalyst composite 5.

Example 6
In this example, the catalyst composite 3 obtained in Example 3 was pulverized to produce a pulverized catalyst composite.
Except that the catalyst composite 3 was used, the operation of Example 4 was repeated to obtain a catalyst composite 6.

Example 7
The operation of Example 3 was repeated to obtain catalyst composite 7. The support of palladium on the spherical activated carbon was observed with an electron microscope (FIG. 1). Binding of palladium particles of about 8 nm was observed at (A) near the surface, (B) 55.4 μm deep, (C) 113.5 μm deep, and (D) 185.2 μm deep. At any depth, there was no significant difference in the particle size and loading of the palladium particles, and the particles were uniformly loaded.

Example 8
In this example, the catalyst composite 7 obtained in Example 7 was pulverized to produce a pulverized catalyst composite.
Except that the catalyst composite 7 was used, the operation of Example 4 was repeated to obtain a catalyst composite 8.

Example 9
The spherical activated carbon obtained in Example 3 was further oxidized in a fluidized bed at 470 ° C. for 30 minutes in a mixed gas atmosphere of nitrogen and oxygen having an oxygen concentration of 16.6 vol% to obtain a catalyst composite 9. The characteristics of the resulting catalyst composite 9 are shown in Table 1.

Example 10
Except that the time for the oxidation treatment was 90 minutes, the operation of Example 9 was repeated to obtain a catalyst composite 10. The characteristics of the resulting catalyst composite 10 are shown in Table 1.

Example 11
In this example, an infusible porous spherical pitch was obtained by the same operation as in Example 1. Thereafter, in the nitrogen gas containing the obtained infusible porous spherical pitch and water vapor of 50 vol%, the catalyst composite 11 was prepared using spherical activated carbon prepared by performing activation treatment until the bulk density became 0.57 g / cm ^3. Obtained. The characteristics of the resulting catalyst composite 11 are shown in Table 1.

<< Comparative Example 1 >>
In this comparative example, a catalyst composite was produced using spherical activated carbon having a bulk density of 0.557 g / cm ³ .
A comparative catalyst composite 1 was obtained by repeating the operation of Example 1 except that the activation treatment was performed until the bulk density of the spherical activated carbon became 0.557 g / cm ³ .

<< Comparative Example 2 >>
In this comparative example, a catalyst composite was produced using spherical activated carbon having a bulk density of 0.605 g / cm ³ .
A comparative catalyst composite 2 was obtained by repeating the operation of Example 1 except that the activation treatment was performed until the bulk density of the spherical activated carbon became 0.605 g / cm ³ .

<< Comparative Example 3 >>
In this comparative example, a catalyst composite was prepared using commercially available crushed coal as a carrier.
The procedure of “(2) Palladium loading” in Example 1 was repeated except that crushed charcoal (granular white birch C2c: Nihon Envirochemicals) was used instead of the spherical activated carbon obtained in Example 1. Comparative catalyst composite 3 was obtained.

<< Comparative Example 4 >>
In this comparative example, a catalyst composite was produced using a commercially available cylindrical granulated coal as a carrier.
The procedure of “(2) Palladium loading” in Example 1 was repeated except that granulated coal (granular white birch C2x: Nihon Envirochemicals) was used instead of the spherical activated carbon obtained in Example 1. Thus, a comparative catalyst composite 4 was obtained.

<< Comparative Example 5 >>
A comparative catalyst composite 5 was obtained by repeating the operation of Example 1 except that the steps after the firing treatment were not performed.
Fig. 2 shows the support of palladium on the spherical activated carbon. (A) In the vicinity of the surface, the palladium particles aggregated to form large secondary particles. However, as the distance from the surface increases, the particle size of palladium decreases and the loading amount also decreases. (C) At a depth of 110.2 μm, the particle size of palladium was about 3 nm. In addition, at a depth of (D) 187.6 μm, the supported amount of palladium particles was very small.

The catalyst composite using the spherical activated carbon of the present invention has a low impurity content, particularly a low sulfur content.

The catalyst composite using the spherical activated carbon of the present invention has a small amount of carbon dust and excellent wear resistance compared to the supported catalyst using granulated coal or crushed coal.

《Reduction test》
A reduction test was performed using the obtained catalyst composite and the comparative catalyst composite. Further, a commercially available powdery palladium-supported catalyst (palladium supported amount 5 wt%) was measured as Comparative Example 6.

(Triple bond reduction test)
Diphenylacetylene 0.5 mmol and methanol 1 cm ³ were added to a test tube, and a catalyst was added thereto so that the amount of metal Pd was 1 mol% with respect to the reaction substrate. Next, the test tube was capped and degassed repeatedly to replace the inside of the test tube with a hydrogen atmosphere. Then, it was made to react by stirring for a predetermined time at room temperature. After completion of the reaction, the catalyst was removed by filtration, the composition of the reaction solution was analyzed by NMR, and the reaction results were determined. The results are shown in Table 5.

(Reduction test of aromatic ketone)
An aromatic ketone reduction test was performed by repeating the operation of “triple bond reduction test” except that benzophenone was used instead of diphenylacetylene. The results are shown in Table 6.

(Nitro group reduction test)
The procedure of “triple bond reduction test” was repeated except that 4-nitroanisole was used in place of diphenylacetylene, and a nitro group reduction test was conducted. The results are shown in Table 7.

(Reduction test of coupling reaction)
A coupling reaction of Suzuki-Miyaura reaction was performed. The R group in the following formula (5) was examined for “NO ₂ ” and “MeO”.

4-Bromonitrobenzene or 4-bromoanisole 0.5 mmol, phenylboronic acid 0.55 mmol, sodium phosphate 3.5 equivalents 665 mg, 50 mol isopropanol 2 mol added to 0.5 mol% with respect to 4-bromonitrobenzene Reacted for hours. After completion of the reaction, the reaction solution was filtered to remove the catalyst, followed by extraction with 20 mL of ether and 15 mL of water, and then the aqueous layer was extracted again to collect the reaction product on the ether side. The extracted reaction product was washed with saturated brine and dried over magnesium sulfate to obtain a reaction product. The composition of the reaction product was analyzed by NMR after adding 0.5 mmol of 1,1,2,2-tetrachloroethane as an internal standard, and the reaction results were determined. The results are shown in Table 8.

As shown in Table 5, the catalyst composite of the present invention was able to efficiently reduce triple bonds.

As shown in Table 6, the low-density catalyst composites of Examples 1 to 3 have a higher reaction rate than the high-density catalyst composites of Comparative Examples 1 and 2, and the final product is produced in a short time. Product yield was 100%. Even when compared with the catalyst composites of Comparative Examples 3 and 4 using crushed coal or granulated coal and the commercially available supported catalyst of Example 6, excellent catalytic action was shown. The pulverized catalyst composites of Examples 4 to 6 in which the spherical catalyst composite was crushed further improved the reaction rate, and the reaction was completed in 3 hours. Furthermore, the reaction rates of the catalyst composites of Examples 9 and 10 using oxidized spherical activated carbon were improved.

As shown in Table 7, the catalyst composites of Examples 7 and 8 efficiently reduced nitro groups compared to the commercially available powdered palladium-supported catalyst of Comparative Example 6.

As shown in Table 8, when the R group is NO _2, reaction time of 3.5 hours and 24 hours, the final product 63% and 100% was obtained. When the R group was MeO, the reaction time was 21 hours and 24 hours, and 82% and 94% of final products were obtained, respectively. The catalyst composite of the present invention was able to efficiently catalyze the coupling reaction.

Since the catalyst composite of the present invention exhibits an excellent reduction action, it can be used as a reduction catalyst in various reduction reactions. In addition, the catalyst composite of the present invention is excellent in strength and exhibits high wear resistance, and thus can be used in various reaction systems. Moreover, since it is spherical, it has good fluidity and excellent operability.
As mentioned above, although this invention was demonstrated along the specific aspect, the deformation | transformation and improvement obvious to those skilled in the art are included in the scope of the present invention.

Claims

A catalyst composite in which a platinum group metal is supported on spherical activated carbon, wherein the bulk density is 0.54 g / cm 3 or less.
The catalyst according to claim 1, wherein the carbon source of the spherical activated carbon is a carbon source selected from the group consisting of petroleum pitch, petroleum tar, coal pitch, coal tar, hot melt resin, and heat infusible resin. Complex.
The catalyst composite according to claim 1 or 2, wherein the amount of platinum group metal supported is 30% by weight or less.
The catalyst composite according to any one of claims 1 to 3, having a bulk density of 0.45 to 0.54 g / cm 3 .
The catalyst composite according to any one of claims 1 to 4, wherein the crushing strength is 800 g / piece.
The catalyst composite according to any one of claims 1 to 5, wherein the sulfur content is 0.05% by weight or less.
The catalyst composite according to any one of claims 1 to 6, wherein the pore volume having a pore diameter of 100 to 500 nm is 0.03 to 0.10 cm 3 / g.
The catalyst composite according to any one of claims 1 to 7, wherein the total acidic groups are 0.3 mmol / g or more.
The catalyst composite according to any one of claims 1 to 8, wherein the pulverization amount by the carbon dust method is 800 ppm or less.
A crushed catalyst composite, characterized in that the catalyst composite according to any one of claims 1 to 9 is crushed.
A reduction method comprising mixing the catalyst complex according to any one of claims 1 to 10 with a compound to be reduced.