NL1039506C2 - METHOD FOR PRODUCING A PRECIOUS METAL CATALYST - Google Patents

Description

Process for producing a precious metal catalyst

Technical area

The present application has been filed and claims priority based on Japanese Patent Application No. 2011-078750 (filed March 31, 2011), the entire contents of which are incorporated herein for reference.

The present invention relates to a process for producing a noble metal catalyst. The present invention also relates to a process for producing an alkylene oxide in which the noble metal catalyst is used.

10 Background of the field

A noble metal catalyst and a titanosilicate catalyst are used in a process in which hydrogen, oxygen and propylene react to produce propylene oxide. As such, a noble metal catalyst, a catalyst obtained by supporting palladium on activated carbon, and then calcining the result, is known from JP 2010-168358 A, for example.

Summary of the invention Problem to be solved by the invention There was a demand for a catalyst that can produce an alkylene oxide with a high yield.

Means for Solving the Problem The present invention provides the following: [1] A method for producing a noble metal catalyst, comprising the steps of: 1) mixing a carbon material with a resin in a solvent to form a mixture to prepare; 2) removing a carbon treated with the resin from the mixture prepared in step 1; 1039506 2 3) heating the resin-treated carbon material removed in step 2 to obtain a support; and 4) supporting a noble metal on the support obtained in step 3.

[2] The method according to the item [1] above, wherein the resin is at least one resin selected from the group consisting of polyvinyl alcohol, polyvinyl acetate, polymethyl methacrylate and polystyrene.

[3] The method according to item [1] or [2] above, wherein the noble metal is at least one metal selected from the group consisting of palladium, ruthenium, rhodium, iridium, osmium and gold.

[4] A catalyst for producing an alkylene oxide comprising a titanosilicate catalyst and a noble metal catalyst produced by the process according to any of the items [1] to [3] above.

[5] A process for producing an alkylene oxide comprising reacting hydrogen, oxygen, and an olefin in the presence of the catalyst produced by the process of the above item [4] [6] The process of the above item ([5], wherein the olefin is propylene.

[7] The method according to item [5] or [6] above, wherein the titanosilicate catalyst is at least one catalyst selected from the group consisting of titanosilicate with an MWW structure and a precursor thereof.

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Effect of the invention

According to the present invention, a catalyst can be provided that can produce an alkylene oxide in high yield.

Methods for carrying out the invention

The process of the present invention is a process for producing a noble metal catalyst, comprising the steps of: 1) mixing a carbon material with a resin in a solvent to prepare a mixture; 2) removing a carbon-treated resin material from the mixture prepared in step 1; 3) heating the resin-treated carbon material removed in step 2 to obtain a support; and 4) supporting a noble metal on the support obtained in step 3.

The noble metal catalyst produced by the present process can generate hydrogen peroxide from oxygen and hydrogen. In addition, by using the noble metal catalyst in combination with a titanosilicate catalyst, the noble metal catalyst is suitable as a catalyst for use in the production of an alkylene oxide (hereinafter, the production of an alkylene oxide is sometimes described as the present production ').

Step 1 is a step in which a carbon material and a resin are mixed in a solvent to prepare a mixture.

The carbon material is a material that mainly consists of carbon. Examples of carbon material include activated carbon, carbon black, graphite and carbon nanotube. Of these, the activated carbon is preferred because it has a larger surface area.

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The raw materials of the activated carbon and the asset method thereof are not specifically limited, and the activated carbon with a large pore volume is preferred. Examples of raw materials of activated carbon include wood, sawdust, palm shell, coal and petroleum materials. Activated carbon obtained by a method in which charcoal obtained from the above-mentioned raw materials is activated by subjecting to a high temperature treatment by means of water vapor, carbon dioxide, air or the like, or a method in which charcoal is activated by means of chemical substances such as zinc chloride is preferred. The activated carbons that have been activated by the above-mentioned methods are preferred because their pore volume and average pore size become larger. The shape of the activated carbon is not specifically limited, and powdered activated carbon, granular activated carbon, milled activated carbon, fibrous activated carbon, honeycomb activated carbon or the like can be used.

The resin used in the method of the present invention is not specifically limited and any known resin can be used. It is preferable to use a resin that is soluble in a solvent used in step 1.

Examples of the resin include polyethylene, polypropylene, polybutadiene, polystyrene, polymethyl methacrylate, polyacrylonitrile, polyacrylic acid, polyethylene glycol, polyvinylpyrrolidone, polyurea, polyester, polyurethane, polyimide, polyethyleneimine, polyvinyl alcohol, polyvinyl chloride, polyvinyl polyfluorate, polyvinyl acetate, polyvinyl polyfluorate, nylon 6 , Nylon 66 and a silicone resin. Of these, polyvinyl alcohol, polyvinyl acetate, and polymethyl methacrylate are preferred, and polyvinyl is more preferred. These resins are easily available. When the noble metal catalyst produced by means of such a resin is used in the present production, the yield of an alkylene oxide tends to increase and the generation of an alkane as a by-product tends to decrease.

As the solvent used in the process of the present invention, a solvent capable of dissolving the aforementioned resin is preferred. The solvent can be selected correctly depending on the type of resin to be used. Examples of such a solvent include water, alcohol solvents, ketone solvents, nitrile solvents, ether solvents, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, ester solvents, glycol solvents, and amide solvents.

Examples of the alcohol solvent include methanol, ethanol, isopropanol, tert-butanol, 1-hexanol, cyclohexanol, and 2-ethylhexanol.

Examples of the ketone solvent include acetone, 2-butanone, 2-heptanone and cyclohexanone.

Examples of the nitrile solvent include acetonitrile and benzonitrile.

Examples of the ether solvent include diethyl ether, tetrahydrofuran and anisole.

Examples of the aliphatic hydrocarbon solvent include pentane, hexane, heptane, and cyclohexane.

Examples of the aromatic hydrocarbon solvent include benzene, toluene and xylene.

Examples of the halogenated hydrocarbon solvent include dichloromethane, chloroform, carbon tetrachloride and dichloroethane.

Examples of the ester solvent include ethyl acetate, propyl acetate, butyl acetate, ethyl propionate, ethyl lactate, and ethyl pyruvate.

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Examples of the glycol solvent include ethylene glycol, diethylene glycol, and propylene glycol.

Examples of the amide solvent include formamide, acetamide, N, N-dimethylformamide, N, N-dimethylacetamide.

These solvents can be used alone or as a mixture of two or more types thereof.

In step 1, a carbon material and a resin are mixed in a solution to prepare a mixture.

In the blend, the amount of carbon material in the blend is preferably from 1 to 10,000 parts per mass, more preferably from 2 to 1,000 parts per mass, based on one part per mass of the resin. The amount of the resin in the mixture is preferably from 0.001 to 50 mass%, more preferably from 0.01 to 20 mass%, based on the total amount of the resin and the solvent.

The temperature for mixing the carbon material with the resin is preferably from 10 ° C to 200 ° C, more preferably from 20 ° C to 150 ° C. The mixing time is preferably from 10 minutes to 30 hours, more preferably from 1 hour to 24 hours. The order of mixing is not specifically limited, but it is preferred that the resin is dissolved in the solvent and then the carbon material is added thereto. The mixing can be carried out under a nitrogen atmosphere or in the air.

Step 2 is a step in which a resin-treated carbon material is removed from the mixture prepared in step 1.

The mixture prepared in step 1 is preferably cooled (i.e., a cooling process is performed). Cooling of the mixture tends to increase adhesion of the carbon material to the resin even when an affinity between the carbon material and the resin is low.

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The mixture is preferably cooled to a temperature of 0 ° C to 50 ° C, more preferably of 0 ° C to 30 ° C. In addition, the mixture is preferably cooled to a temperature which is preferably 10 ° C to 200 ° C, more preferably 20 ° C to 150 ° C, and even more preferably 30 ° C to 120 ° C lower than the mixing temperature of step 1. The time for cooling the mixture is preferably from 30 minutes to 36 hours, more preferably from 1 hour to 24 hours. The cooling can be carried out under a nitrogen atmosphere or air.

In step 2, a carbon-treated carbon material can be removed from the mixture by filtration, for example.

The carbon material treated with the resin can be dried if necessary. When the carbon material is dried, the temperature is preferably from 30 ° C to 200 ° C. It is preferable to dry the mixture under a reduced pressure or under an atmosphere or an inert gas.

Step 3 is a step in which the resin-treated carbon material obtained in step 2 is heated to obtain a support.

The heating temperature is preferably from 250 ° C to 800 ° C, more preferably from 250 ° C to 600 ° C. The heating time is preferably from 30 minutes to 24 hours, more preferably from 1 hour to 12 hours.

The heating can be carried out under an atmosphere of an inert gas or air. The heating is preferably carried out under an atmosphere of an inert gas. Examples of the inert gas include nitrogen gas and a noble gas such as argon gas.

Step 4 is a step in which a noble metal is supported on the support obtained in step 3 (hereinafter the support is obtained in step 3 sometimes described as a "support (A)").

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As noble metal, for example, palladium, platinum, ruthenium, osmium, rhodium, iridium and gold can be used. The noble metal can be used alone or as an alloy or mixture of two or more kinds thereof. More specifically, the noble metal is preferably palladium, platinum, gold and an alloy or mixture thereof, more preferably palladium, an alloy or mixture of palladium and gold, or an alloy or mixture of palladium and platinum, with an even more preferred palladium. When the noble metal catalyst produced by means of such a noble metal is used in the present production, generation of hydrogen peroxide in the system tends to increase and the yield of an alkylene oxide tends to increase in the present production.

Examples of the method of supporting a noble metal on the support (A) include a method of supporting a noble metal compound on the support (A) and then reducing the noble metal, and a method of mixing a noble metal colloidal noble metal and the support (A).

In the method for supporting a noble metal compound on the support (A) and then reducing the noble metal compound, for example, a noble metal compound is first supported on the support (A) by an impregnation method and, subsequently, the noble metal compound is reduced to form zero-valent precious metal.

Examples of the noble metal compound include noble metal chlorides. When palladium is used as a noble metal compound, examples of the palladium compound include tetravalent palladium compounds such as sodium hexachloropalladate (IV) tetrahydrate and potassium hexachloropalladate (IV); and divalent palladium compounds such as palladium (II) chloride, palladium (II) bromide, palladium (II) acetate, palladium (II) acetylacetonate, dichlorobis (benzonitrile) palladium (II), dichlorobis (acetonirtil) palladium (II), dichloro-9 ro (bis (diphenylphosphine) ethane) palladium (II), dichloro bis (triphenylphosphine) palladium (II), dichlorotetraamine palladium (II), dibromotetraamine palladium (II), dichloro (cycloocta-1,5-diene) palladium (II) , and palladium (II) trifluoroacetate.

The impregnation process can be carried out, for example, by impregnating a solution of the noble metal compound (e.g., an aqueous solution of the above-mentioned noble metal compound) with the support (A) at room temperature for 10 minutes to 30 hours.

A noble metal catalyst can be obtained by reducing the noble metal compound containing the support (A) that supports the noble metal. For example, the noble metal compound can be reduced by a method of reducing by means of a reducing agent in a liquid phase or a gas phase. As a gas phase reduction, a method can be used in which hydrogen is used as a reducing agent and the reduction is carried out at a temperature of 0 ° C to 500 ° C.

When a noble metal compound that generates ammonia gas at the time of thermal decomposition under an inert gas atmosphere is used as a noble metal compound, the noble metal compound supported on a support can be subjected to a thermal treatment under an inert gas atmosphere. In this case, ammonia gas generated from the noble metal compound serves as a reducing agent. The temperature of the thermal treatment can vary depending on the type of noble metal compound used and the like. When dichlorotetraamine palladium (II) is used as a noble metal compound, the temperature is preferably from 100 ° C to 500 ° C, more preferably from 200 ° C to 350 ° C.

When the reduction is carried out in a liquid phase (liquid phase reduction), hydrogen, hydrazine monohydrate, formaldehyde and sodium borohydride can be used as a reducing agent.

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When hydrazine monohydrate or formaldehyde is used, it can be used in combination with an alkali. Conditions for the liquid phase reduction can be suitably adjusted, depending on the type and amount of the noble metal compound, the carrier and the reducing agent to be used.

When a noble metal catalyst is prepared by a process in which a colloidal noble metal and the support (A) are mixed, for example, the colloidal noble metal and the support (A) are mixed in a solvent (e.g. water), and then the mixed 10 filtered to obtain a solid. As a solvent, a dispersion medium of the colloidal noble metal can be used per se.

The temperature for mixing is not specifically limited, and is preferably from 0 ° C to 100 ° C, more preferably from 15 ° C to 40 ° C. The time for mixing is not specifically limited, and is preferably from 10 minutes to 30 hours, more preferably from 30 minutes to 18 hours.

As a colloidal noble metal, a commercially available product can be used, and also a colloidal noble metal prepared by dispersing noble metal particles with a dispersing agent, such as citric acid, polyvinyl alcohol, polyvinyl pyrrolidone and sodium hexametaphosphate.

In the noble metal catalyst prepared by the present process, the noble metal content is preferably 0.01 to 20 mass%, more preferably 0.1 to 10 mass%, based on the mass of the carbon material it contains precious metal supports.

The catalyst of the present invention comprising the noble metal catalyst produced by the process of the present invention and titanosilicate catalyst is suitable for producing an alkylene oxide.

An alkylene oxide can be produced by reacting hydrogen, oxygen, and an olefin in the presence of a titanium silicate catalyst and the noble metal catalyst prepared by the process of the present invention.

The titanosilicate catalyst is a catalyst consisting essentially of titanosilicate and has a potential for olefin epoxidation.

In the following, the titanosilicate from which the titanosilicate catalyst is composed is described in detail.

Titanosilicate is a generic name for a silicate comprising tetra-coordinated Ti (titanium atom), and has a porous configuration. The titanosilicate of which the titanosilicate catalyst is composed refers to a titanosilicate essentially comprising tetra-coordinated Ti, wherein a maximum absorption peak of an ultraviolet-visible absorption spectrum occurs in a wavelength range of 200 nm to 400 nm in a wavelength range of 210 nm to 230 nm (see, for example, "Chemical Communications" 1026-1027, (2002), Figures 2 (d) and (e). The ultraviolet-visible absorption spectrum can be measured by means of an ultraviolet-visible spectrophotometer equipped with a diffuse reflector according to a diffuse reflection method.

As the titanosilicate from which the titanosilicate catalyst is composed, fine-pore titanosilicate with no less than 10-membered oxygen ring is preferred because such a titanosilicate has a high potential for olefin epoxidation. If the fine pores are too small, contact between olefins fed into the fine pores and active points in the fine pores can be prevented, or mass transfer of olefins into the fine pores can be reduced. The fine pore herein refers to a pore formed with an Si-0 bond and / or a Ti-0 bond. The fine pore can take the form of a half-bowl, called a side pocket, and does not have to penetrate the primary particle of titanosilicate. The term "no less than 10 membered oxygen ring" means that the number of oxygen atoms is 10 or more in either (a) a cross section of the narrowest part of the fine pore, or (b) a ring structure on the 12 entrance of the fine pore. The fact that a titanosilicate catalyst has fine pores of no less than 10-membered oxygen ring is generally confirmed by an analysis of an X-ray diffraction pattern. In addition, if the catalyst has a known structure, the structure can be easily confirmed by comparing its X-ray diffraction pattern with the known X-ray diffraction pattern.

Examples of the titanosilicate of which the titanosilicate catalyst is composed include the titanosilicates described below [1] to [7], [1] Crystalline fine pore titanosilicate with a 10-membered oxygen ring: TS-1 comprising the MFI structure (e.g., US 4,410,501), TS-2 comprising the MEL structure (e.g., Journal of Catalysis 130, 440-446, (1991)), Ti-ZSM-48 comprising the MRE structure (e.g., Zeolites 15 , 164-170, (1995)), Ti-FER comprising the FER structure (e.g., Journal of Materials Chemistry 8, 1685-1686 (1998)), and the like, in terms of the IZA (International Zeolite Association) structure code.

[2] Crystalline fine pore titanosilicate with a 12-membered oxygen ring:

Ti-Beta comprising a BEA structure (e.g., Journal of Catalysis 199, 41-47, (2001)), Ti-ZSM-12 comprising an MTW structure (e.g., Zeolites 15, 236-242), (1995)) , Ti-MOR comprising an MOR structure (e.g., The Journal of Physical Chemistry B 102, 9297-9303, (1998)), Ti-ITQ-7 comprising an ISV structure (e.g., Chemical Communications 761-762 (2000)), Ti-MCM-68 comprising an MSE structure (for example, Chemical Communications 6224-6226, (2008)), Ti-MWW comprising an MWW structure (for example, Chemistry Letters 774-775, (2000)), and the like.

13 [3] Crystalline fine pore titanosilicate with a 14-membered oxygen ring:

Ti-UTD-1 comprising a DON structure (for example, Studies in Surface Science and Catalysis 15, 519-525, (1995)), and the like.

[4] Fine pore layered titanosilicate with a 10-membered oxygen ring:

Ti-ITQ-6 (for example, Angewandte Chemie International Edition 39, 1499-1501, (2000)), and the like.

10 [5] Fine pore layered titanosilicate with a 12-membered oxygen ring:

A Ti-MWW precursor (e.g., EP-1731515-A &), Ti-YNU-1 (e.g., Angewandte Chemie International Edition 43, 236-240), (2004)), Ti-MCM-36 (e.g., Catalysis Letters 113 , 160-164, 15 (2007)), Ti-MCM-56 (e.g., Microporous and Mesoporous Materials 113, 435-444, (2008)), and the like.

[6] Mesoporous titanosilicate:

Ti-MCM-41 (e.g., Microporous Materials 10, 259-271, (1997)), Ti-MCM-48 (e.g., Chemical Communications 145-20 145, (1996)), Ti-SBA-15 (e.g., Chemistry of Materials 14, 1657-1664, (2002)), and the like.

14 [7] Silylated titanosilicate;

Compounds obtained by silylation of the above-described titanosilicates [1] to [4], such as silylated Ti-MWW.

The term "12-membered oxygen ring" means a ring structure comprising 12 oxygen atoms in region (a) or in region (b) mentioned in the description with regard to "10-membered oxygen ring". Similarly, the term "14-membered oxygen ring" means a ring structure comprising 14 oxygen atoms in the aforementioned region (a) or in region (b).

The titanosilicate can be a titanosilicate with a layered structure such as a layered precursor of a crystalline titanosilicate, a titanosilicate with gaps between layers in a crystalline titanosilicate. Whether or not a titanosilicate has a layered structure can be confirmed by electron microscopy or measurement of an X-ray diffraction pattern. The layered precursor refers to a titanosilicate that forms a crystalline titanosilicate by a treatment such as dehydration condensation. It can easily be determined from the structure of a corresponding crystalline titanosilicate that a layered titanosilicate has fine pores of no less than 12-membered oxygen ring.

The Ti-MWW precursor refers to a titanosilicate with a layered structure that forms a Ti-MWW through a dehydration condensation. The dehydration condensation can be carried out by heating the Ti-MWW precursor, usually at a temperature of more than 200 ° C to 1000 ° C or less, preferably a temperature in the range of 300 ° C to 650 ° C.

The titanosilicates from [1] to [5] and [7] have fine pores with a pore size of 0.5 to 1.0 nm. The pore size refers to the longest distance of (a) a cross-section of the narrowest part of the fine pore and (b) a fine pore entrance. The pore size preferably refers to a diameter in the aforementioned regions (a) and (b).

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The pore size can be determined by an analysis of an X-ray diffraction pattern.

Among the above-mentioned titanosilicates, a mesoporous titanosilicate having regular mesophinic pores is preferred. The regular mesophine pore refers to a structure in which mesopores have been regularly and repeatedly applied. When the titanosilicate is a mesoporous titanosilicate, the mesoporous titanosilicate having mesophine pores with an average pore size of 2 nm to 10 nm is more preferred.

Silylation of the titanosilicates can be carried out by a method in which the titanosilicate is contacted with a silylating agent or a method described in EP 1488853 A1. Examples of the silylating agent include 1,1,1,3,3,3-hexamethyldisilazane and trimethylchlorosilane.

Of the above-mentioned titanosilicates from [1] to [7], Ti-MWW and Ti-MWW precursor are preferably used, and Ti-MWW precursor is more preferably used as a titanosilicate from which the titanosilicate catalyst is composed. The silylated Ti-MWW or Ti-MWW precursor can be used for a titanosilicate catalyst. The Ti-MWW or Ti-MWW precursor formed by a known method can be used for a titanosilicate catalyst.

In the titanosilicate catalyst used in the present production, the titanium atom content is preferably from 0.001 to 0.1 mole, more preferably from 0.005 to 0.05 mole, based on one mole of incorporated silicone atoms.

In the present production, the noble metal catalyst obtained by the process of the present invention is preferably used at a level of 0.01 to 100 parts per mass, more preferably 0.1 to 100 parts per mass, based on one part per mass of the titanosilicate catalyst used.

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The present production is preferably carried out in a solvent. Water, an organic solvent and mixtures thereof are preferred as the solvent. Examples of the organic solvent include alcohol solvents, ketone solvents, nitrile solvents, ether solvents, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, ester solvents, glycol solvents and mixtures thereof . Of these, nitrile solvents are preferred.

Examples of the nitrile solvent include linear or branched saturated aliphatic nitriles and aromatic nitriles. The specific examples of the nitrile solvent include acetonitrile, propionitrile, isobutyronitrile and benzonitrile. Acetonitrile is preferred.

The solvent is preferably a mixed solvent of water and nitrile. In the mixed solvent, a mass ratio of water and nitrile (water: nitrile) is preferably from 90: 10 to 0.01: 99.99, more preferably from 50: 50 to 0.1: 99.9, with a even more preferably 40: 60 to 5: 95.

In the present production, oxygen can be a molecular oxygen, such as an oxygen gas. The oxygen gas can be an oxygen gas produced by a pressure change method or an oxygen gas of high purity produced by cryogenic separation. Alternatively, air can be used as oxygen.

In the present production, a hydrogen gas is usually used as hydrogen.

The oxygen gas and / or hydrogen gas used in the present production can be diluted with an inert gas that does not interfere with the progress of the present production. Examples of the inert gas include nitrogen, argon, carbon dioxide, methane, ethane and propane.

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The amounts of oxygen gas and hydrogen gas applied to the present production and the concentration of the inert gas used to dilute the gases can be appropriately adjusted according to an amount of the olefin to be used, the scale of the reaction, and the like.

The molar ratio of oxygen and hydrogen applied to the reactor (oxygen: hydrogen) is, for example, preferably from 1: 50 to 50: 1, more preferably from 1: 5 to 5: 1.

Examples of an olefin used in the present production include linear or branched olefins with 2 to 10 carbon atoms and cyclic olefins with 4 to 10 carbon atoms.

Examples of the linear and branched olefin with 2 to 10 carbon atoms include ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, 2-butene, isobutene, 2-15 pentene, 3-pentene, 2-hexene, 3-hexene, 4-methyl-1-pentene, 2-heptene, 3-heptene, 2-octene, 3-octene, 2-nonene, 3-nonene, 2-decene, and 3-decene.

Examples of the cyclic olefin having 4 to 10 carbon atoms include cyclobutene, cyclopentene, cyclohexane, cyclohepene, cyclooctene, cyclononene, and cyclodecene.

A preferred olefin is a linear or branched olefin with 2 to 6 carbon atoms, and more preferably, the olefin is propylene.

In the present production, the olefin is preferably used at a level of 0.2 to 5 moles based on one mole of oxygen. When the present production is carried out in the continuous manner, the olefin is preferably used at a level of 0.01 to 1000 g, based on 1 kg of the solvent used in the present production.

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Examples of the reactor used in the present production include a flow-through fixed-bed reactor and a flow-through slurry complete mixer.

The reaction temperature of the present production is preferably from 0 ° C to 150 ° C, more preferably from 40 ° C to 90 ° C.

In the present production, the pressure is preferably 0.1 MPa to 20 MPa, more preferably 1 MPa to 10 MPa as an overpressure.

After completion of the present production, the alkylene oxide can be removed by distillation to separate a substance from the liquid phase or gas phase that was withdrawn from the reactor.

It is preferable to carry out the present production in the presence of a polycyclic compound as an additive. It is preferable to use the polycyclic compound in the present production because generation of propane as a by-product tends to be suppressed and hydrogen efficiency tends to improve. The hydrogen efficiency herein refers to a product amount of propylene oxide relative to the amount of hydrogen consumed.

The specific examples of the polycyclic compound include anthracene, tetracene, 9-methyl anthracene, naphthalene, diphenyl ether, anthraquinone, 9.10-phenanthraquinone, benzoquinone, 2-25 ethyl anthraquinone, as well as the compounds described in JP 2009- 23998 A and JP 2008 -106030 A. Of these, a condensed polycyclic aromatic compound such as anthracene, tetracene, 9-methyl anthracene, naphthalene, anthraquinone, 9,10-phenanthraquinone and 2-ethyl anthraquinin is preferable, more preferably anthra-quinone.

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In the present production, the polycyclic compound is preferably used at a level of 0.001 to 500 mmol, more preferably 0.01 to 50 mmol, based on 1 kg of the solvent used in the present production.

In the present production, a salt with an ammonium ion, an alkylammonium ion or an alkylarylammonium ion (hereinafter the salt is sometimes collectively defined as "ammonium salt") can be used as an additive. When the ammonium salt is used in the present production, the hydrogen efficiency tends to be improved.

Examples of the ammonium salt include ammonium salts of an inorganic acid, such as ammonium sulfate, ammonium hydrogen sulfate, ammonium hydrogen carbonate, ammonium phosphate, ammonium hydrogen phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium hydrogen pyrophosphate, ammonium pyrophosphate, ammonium halides, ammonium halides and ammonium halides; and ammonium salts of an organic acid, such as ammonium acetate. Among them, diammonium hydrogen phosphate is preferred.

In the present production, the ammonium salt is preferably used at a level of 0.001 to 100 mmol based on 1 kg of the solvent used in the present production.

The reaction mixture obtained by reacting hydrogen, oxygen and an olefin in the presence of a noble metal catalyst prepared by the process of the present invention and a titanosilicate catalyst contains an objective alkylene oxide, an unreacted olefin and an alkane as a by-product . The objective alkylene oxide can be taken from the reaction mixture by a known purifying agent, such as separation by distillation.

Examples 20

In the following, the present invention is described in more detail with reference to Examples. Analytical instruments and analysis methods used in the following examples are as follows.

(Elemental analysis) 5 (1) Content of Pd (palladium atoms) in the activated carbon supporting Pd or the noble metal catalyst was measured by the microwave deposit / ICP emission spectrometry (the observation limit is 0.01 mass% or less) .

(2) Content of Ti (titanium atoms) and Si (Silicone atoms) in the titanosilicate catalyst were measured by the alkali solution / solution in nitric acid / ICP emission spectrometry.

(Powder X-ray diffractometry)

A powder X-ray diffraction pattern of the steel was determined by the following device under the following conditions.

Device: RINT 2500 V manufactured by Rigaku Denki Co., Ltd.

Radiation source: Cu K-a radiation

Output voltage: 40 kV - 300 mA 20 Scan area: 29 = 0.75 ° to 30 °

Scan speed: 1 "/ minute

When the measured X-ray diffraction pattern was the same as that described in FIG. 1 of EP 1731515, it was decided that the measured steel was Ti-MWW precursor. When the measured X-ray diffraction pattern was the same as that described in FIG. 2 of EP 1731515, it was decided that the measured steel was Ti-MWW.

(Ultraviolet-visible absorption spectrum)

The steel was thoroughly pulverized in an agate mortar and formed into pellets (7 mm diameter) to prepare a sample for measurement. An ultraviolet / visible absorption spectrum of the steel was determined by the following device under the following conditions.

Device: a diffusion reflector (Praying Mantis manufactured by HARRICK) 5 Device accessory: an ultraviolet-visible spectrophotometer (V-7100 manufactured by JASCO Corporation)

Pressure: atmospheric pressure Measured value: coefficient of reflection Time data retrieval: 0.1 second 10 Bandwidth: 2 nm

Measuring wavelength: 200 to 900 nm Gap height: half open Data retrieval interval: 1 nm

Baseline correction (reference): BaS04 pellets (7 mm diameter)

When the maximum absorption in a wavelength range of 200 nm to 400 nm occurred in a wavelength range of 210 nm to 230 nm, it was decided that the measured sample was titanosilicate. Example 1 20 (Production of carrier)

A 1 liter eggplant vial was loaded with 1.8 g of polyvinyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., degree of polymerization: 500) and 600 ml of water under a nitrogen atmosphere, and the temperature of the mixture was raised to 90 ° C with continuous stirring. After the mixture was maintained at that temperature for 1 hour, 9.0 g of activated carbon (manufactured by Japan Enviro Chemicals, Ltd., Special Order Shirasagi) and 50 ml of water were added to obtain a suspension, after which the suspension was added for 4 was held at that temperature for one hour. The heat was then removed and the suspension was cooled to room temperature. After the suspension was filtered, the resulting solid was washed with 200 ml of water, and then dried in vacuo at 80 ° C for 10 hours to obtain 10.3 g of resin-activated activated carbon.

3.5 g of the resultant resin treated activated carbon was heated to 300 ° C over 2 hours under a nitrogen atmosphere, and then kept at 300 ° C for 6 hours. The heat was then removed and the resin-treated activated carbon cooled to room temperature to obtain 3.0 g of carrier A.

10 (Production of precious metal catalyst)

A 500 ml eggplant vial was loaded with 2.7 g of carrier A and 270 ml of water under a nitrogen atmosphere, and the mixture was stirred at room temperature. Then, 50 ml of an aqueous dispersion containing 0.27 mmol of colloidal palladium (Pd) (manufactured by JGC Catalysts and Chemicals, Ltd.) was slowly added dropwise to the resulting suspension at room temperature under a nitrogen atmosphere. After completion of the dropwise addition, the suspension was stirred at room temperature for an additional 6 hours under a nitrogen atmosphere. Water was then removed from the suspension by means of a rotary evaporator and the residue was dried in vacuo at 80 ° C for 10 hours to obtain 2.9 g of noble metal catalyst A. The palladium (Pd) content in the noble metal catalyst A, measured by ICP emission spectrometry, was 0.80 mass%.

Preparation Example 1 (Preparation of noble metal catalyst)

A 1 liter eggplant vial was loaded with 9.5 g of activated carbon (manufactured by Japan Enviro Chemicals, Ltd., Special Order Shirasagi) and 900 ml of water under an air atmosphere, and the mixture was stirred at room temperature to prepare a suspension. -30. Then 80 ml of aqueous dispersion containing 0.90 mmol of colloidal palladium (Pd) (manufactured by JGC) was slowly added dropwise.

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Catalysts and Chemicals, Ltd.) added to the resulting suspension at room temperature under an air atmosphere. After completion of the dropwise addition, the suspension was stirred at room temperature for an additional 6 hours under an air atmosphere. The water was then removed from the suspension by means of a rotary evaporator and the residue was dried in vacuo at 80 ° C for 10 hours to obtain 9.5 g of Pd / AC catalyst. The palladium (Pd) content in the Pd / AC catalyst, measured by ICP emission spectrometry, was 0.95 mass%.

Preparation Example 2 (Preparation of calcined Pd / AC catalyst)

Under a nitrogen atmosphere, 2.4 g of the Pd / AC catalyst obtained in Preparation Example 1 was calcined at 300 ° C for 6 hours to obtain 2.4 g of calcined Pd / AC catalyst. The palladium (Pd) content in the calcined Pd / AC catalyst, measured by ICP emission spectrometry, was 1.03 mass%.

Preparation Example 3 (Preparation of titanosilicate catalyst)

In an autoclave, 899 g of piperidine, 2402 g of pure water, 112 g of tetra-n-butyl orthotitanate, 565 g of boric acid, and 410 g of smoked silica (cab-o-sil M7D) were stirred under an air atmosphere to gel. to gain. After the resulting gel had rested for 1.5 hours, the autoclave was sealed. Subsequently, the temperature of the gel was raised to 160 ° C over 8 hours with continuous stirring, and the gel was kept at that temperature for 120 hours to obtain a suspension.

After the resulting suspension was filtered, the filtrate was washed with water until its pH was about 10. The resulting solid was dried at 50 ° C until no more weight loss was observed to obtain 515 g of solid (a). To 75 g of the resulting solid (a) was added 3750 ml of 2 M nitric acid to obtain a mixture, and then the mixture was placed under reflux for 20 hours.

The mixture was then filtered and the resulting solid was washed with water until its pH was nearly neutral, after which the resulting product was tolerated in vacuo at 150 ° C until no more weight loss was observed to yield 61 g of a white powder. (a). The X-ray diffraction pattern and the ultraviolet-visible absorption spectrum of the white powder (a) were measured. As a result, it was confirmed that the white powder (a) was a Ti-MWW precursor 10.

60 g of the obtained white powder (a) was calcined at 530 ° C for 6 hours to obtain 54 g of powder (t). It was confirmed that the powder (t) obtained was a Ti-MWW of the X-ray diffraction pattern, and that the powder (t) was titanosilicate with tetra-coordinated Ti from the ultraviolet-visible absorption center. The same process was repeated twice to obtain a total of 162 g of powder (t).

An autoclave was charged with 135 g of the resulting powder (t) at room temperature under an air atmosphere, and 300 g of pi-peridine and 600 g of pure water were added thereto, after which the mixture was stirred to obtain a gel. After the resulting gel had rested for 1.5 hours, the autoclave was sealed. Subsequently, the temperature of the gel was raised to 160 ° C over 4 hours with continuous stirring, and the gel was kept at that temperature for 24 hours to obtain a suspension.

After the resulting suspension was filtered, the filtrate was washed with water until its pH was about 9. The resulting solid was dried at 150 ° C until no more weight loss was observed to obtain 141 g of white powder (b). The X-ray diffraction pattern and the ultraviolet-visible absorption spectrum of the white powder (b) were measured. As a result, the X-ray diffraction pattern of powder (b) exhibited a pattern similar to that of Ti-MWW precursor, and it was confirmed that the white powder (b) had a fine pore structure of 12-membered oxygen ring. Furthermore, from the ul-traviolet-visible absorption spectrum, it was confirmed that the white powder (b) was titanosilicate. The titanium (Ti) content, measured by ECP emission spectrometry, was 1.61 mass%.

The resulting white powder (b) was stirred in 80 g of a mixed solvent of water / acetonitrile (mass ratio = 20/80) containing 0.1 mass% hydrogen peroxide for 1 hour, and then the mixture was filtered and the filtrate was washed with 80 g of water to obtain titanosilicate catalyst A.

Example 2 (Production of propylene oxide)

A 0.3 l autoclave was used as a reactor. The reactor was charged with 2.28 g of titanosilicate catalyst A and 0.75 g of noble metal catalyst A, after which the autoclave was sealed. A mixed gas of oxygen / hydrogen / nitrogen (volume ratio = 3.4 / 3.8 / 92.8), 135 g / h solution of water / acetonitrile (mass ratio = 30/70) was added to the autoclave at 339 l / h ) containing 0.7 mmol / kg of anthraquinone, 3.0 mmol / kg of diammonium hydrogen phosphate, and 54 g / hour of propylene added, and the continuous reaction (retention time: 40 minutes), in which a solution containing a reaction product (ie liquid phase) and a produced gas (ie gas phase) was withdrawn from the reaction mixture and removed from the reactor through a filter, was carried out. During the reaction, the temperature of the mixture was adjusted to 50 ° C, and the internal pressure of the reactor was adjusted to 6.0 MPa (excess pressure).

The liquid phase and the gas phase removed after four hours after the start of the reaction were analyzed by gas chromatography. As a result, propylene oxide was produced at a level of 30 219.7 mmol / hour, and selectivity of by-product propane was 6.3%.

Comparative Example 1 26

The procedure of Example 2 was repeated with the exception that 0.63 g of Pd / AC catalyst obtained in Preparation Example 1 was used instead of 0.75 g of noble metal catalyst A. An amount of propylene oxide product and side-by-side selectivity Product propane was analyzed in the same manner as in Example 2. As a result, the product content of propylene oxide was 137.1 mmol / hour and selectivity of by-product propane was 9.5%.

Comparative example 2

The procedure of Example 6 was repeated, with the exception that 0.63 g of calcined Pd / AC catalyst obtained in Preparation Example 2 was used instead of 0.75 g of noble metal catalyst A. An amount of propylene oxide and selectivity of by-product propane were analyzed in the same manner as in Example 2. As a result, the product content of propylene oxide was 139.7 mmol / hr and selectivity of by-product propane was 18.5%.

Comparative Example 3

A 0.3 l autoclave was used as a reactor. The reactor was charged with 2.28 g of titanosilicate catalyst A and 1.06 calcined Pd / AC catalyst obtained in Preparation Example 2, after which the autoclave was sealed. A mixed gas of oxygen / hydrogen / nitrogen (volume ratio = 3.3 / 3.6 / 93.1), 90 g / hour solution of water / acetonitrile (mass ratio = 30/70) was added to the autoclave at 281 l / hour 0.7 mmol / kg anthraquinone, 3.0 mmol / kg diammonium hydrogen-phosphate, and 36 g / hour propylene added, and the continuous reaction (retention time: 60 minutes), in which a solution containing a reaction product (ie liquid phase ) and a produced gas (ie gas phase) was withdrawn from the reaction mixture and removed from the reactor through a filter, was carried out. During the reaction, the temperature of the mixture was adjusted to 50 ° C, and the internal pressure of the reactor was adjusted to 4.0 MPa (excess pressure).

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The liquid phase and the gas phase, taken away 6 hours after the start of the reaction, were analyzed by gas chromatography. As a result, propylene oxide was produced at a level of 167.7 mmol / hour, and selectivity of by-product propane was 7.6%.

It was confirmed that a high product content of propylene oxide was obtained by the noble metal catalysts of Example 1 produced by the process of the present invention.

Industrial applicability According to the present process, a catalyst can be provided that can produce an alkylene oxide in high yield.

15 20 25 1039506 30

Claims (7)

A method for producing a noble metal catalyst, comprising the steps of: 1. mixing a carbon material with a resin in a solvent to prepare a mixture; 2) removing a carbon treated with the resin from the mixture prepared in step 1; 3. heating the resin-treated carbon material removed in step 2 to obtain a support; and; 4. supporting a noble metal on the support 10 obtained in step 3. The method of claim 1, wherein the resin is at least one resin selected from the group consisting of polyvinyl alcohol, polyvinyl acetate, polymethyl methacrylate. 3. A method according to claim 1 or 2, wherein the noble metal is at least one metal selected from the group consisting of palladium, platinum, ruthenium, rhodium, iridium, osmium and gold. 4. A process for producing an alkylene oxide comprising reacting hydrogen, oxygen, and an olefin in the presence of a titanosilicate catalyst and a noble metal catalyst produced by the process of any one of claims 1 to 3. 5. A process for producing an alkylene oxide comprising reacting hydrogen, oxygen, and an olefin in the presence of the catalyst produced by the process of claim 4. The method of claim 5, wherein the olefin is propylene. The method according to claim 5 or 6, wherein the titanosilicate catalyst is at least one catalyst selected from the group consisting of a titanosilicate with an MWW structure and a precursor thereof. 5 1039506