Method for producing oxides and method for producing Pt / Bi composite catalysts

Abstract

The present invention relates to a method for producing an oxide with which an oxide of an organic compound can be obtained efficiently in the presence of a raw material for a Pt / Bi composite catalyst, and a method for producing a Pt / Bi composite catalyst with which it is possible to produce a catalyst exhibiting high activity in a dehydrogenation oxidation reaction of an organic compound, even in the present of an organic compound which is the raw material of an oxide.　Provided is a method for producing an oxide, wherein an organic compound that has one primary hydroxyl group is subjected to a dehydrogenation oxidation reaction in the presence of water and a Pt, Bi ion source supported by a carrier, in conditions such that the minimum pH value during the reaction is less than 7, so as to obtain an oxide of the organic compound.

Description

[Technical Field]

[0001] The present invention relates to a method for producing an oxide and a method for producing a Pt / Bi composite catalyst. [Background technology]

[0002] Conventionally, a method has been known in which a noble metal catalyst, Pt, is used in combination with Bi as a promoter to catalytically dehydrogenate and oxidize hydroxy compounds and aldehyde compounds to convert them into the corresponding carboxy compounds and ketone compounds. Japanese Patent Laid-Open Publication No. 2016-120484 (Patent Document 1) discloses a method for preparing a catalyst by adding an aqueous dispersion of a catalyst in which Pt is supported on activated carbon to an aqueous solution containing Bi in an ionic state, and a method for producing an oxide by dehydrogenating alcohol or the like in the presence of the catalyst obtained by the preparation method. Furthermore, Japanese Patent Laid-Open Publication No. 1-146840 (Patent Document 2) discloses a method for producing an ethercarboxylic acid, in which a polyalkoxy alcohol or an aliphatic alcohol alkoxylate is oxidized in an alkaline aqueous phase in the presence of a catalyst containing a noble metal of Group VIII of the periodic table, such as Pd or Pt. Summary of the Invention

[0003] The present invention relates to a method for producing an oxide, which comprises subjecting an organic compound having one primary hydroxyl group to a dehydrogenative oxidation reaction in the presence of Pt supported on a carrier, a Bi ion source, and water, under conditions where the minimum pH during the reaction is less than 7, to obtain an oxide of the organic compound. The present invention also relates to a method for producing a Pt / Bi composite catalyst, which comprises mixing Pt supported on a carrier with a Bi ion source in the presence of an organic compound having one primary hydroxyl group and water, and reacting the resulting mixture under conditions where the minimum pH during the reaction is less than 7. DETAILED DESCRIPTION OF THE INVENTION

[0004] The catalyst preparation method described in Patent Document 1 involves a separate process from the production process of an oxide such as an alcohol, and therefore requires the preparation of a catalyst production facility separate from the production facility for the oxide such as an alcohol. Furthermore, the catalyst preparation process requires a process for separating and purifying the catalyst in addition to a process for preparing raw materials for the catalyst. Furthermore, the prepared catalyst must be stored under appropriate storage conditions until it is used to produce an oxide such as an alcohol. Therefore, there is a problem in that the preparation of the catalyst requires significant cost and labor, separate from the production of the oxide such as an alcohol. Furthermore, the method for producing an ethercarboxylic acid described in Patent Document 2 has a problem in that the productivity of ethercarboxylic acid is low.

[0005] The present invention relates to a method for producing an oxide, which can efficiently produce an oxide of an organic compound in the presence of a raw material for the Pt / Bi composite catalyst, and a method for producing a Pt / Bi composite catalyst, which can produce a catalyst that exhibits high activity in the dehydrogenation reaction of an organic compound even in the presence of the organic compound that serves as the raw material for the oxide.

[0006] The present inventors have found that, even in the presence of raw materials for the Pt / Bi composite catalyst, oxides of organic compounds can be efficiently obtained by maintaining the pH during the reaction at less than 7, and further, that, even in the presence of organic compounds that serve as raw materials for the oxides, a catalyst that exhibits high activity in the dehydrogenative oxidation reaction of organic compounds can be produced by maintaining the pH during the reaction at less than 7. The present invention relates to the following [1] and [2]. [1] A method for producing an oxide, comprising dehydrogenating an organic compound having one primary hydroxyl group in the presence of Pt supported on a carrier, a Bi ion source, and water, under conditions where the minimum pH during the reaction is less than 7, to obtain an oxide of the organic compound. [2] A method for producing a Pt / Bi composite catalyst, which comprises mixing Pt supported on a carrier and a Bi ion source in the presence of an organic compound having one primary hydroxyl group and water, and reacting the mixture under conditions where the minimum pH during the reaction is less than 7.

[0007] The present invention provides a method for producing an oxide, which can efficiently produce an oxide of an organic compound in the presence of a raw material for the Pt / Bi composite catalyst, and a method for producing a Pt / Bi composite catalyst, which can produce a catalyst that exhibits high activity in the dehydrogenation reaction of an organic compound even in the presence of the organic compound that serves as the raw material for the oxide.

[0008] The present invention will be described in detail below.

[0009] [Method of producing oxides] The method for producing an oxide of the present invention comprises dehydrogenating an organic compound having one primary hydroxyl group (hereinafter simply referred to as "organic compound") in the presence of Pt supported on a carrier, a Bi ion source, and water under conditions where the minimum pH during the reaction is less than 7, thereby obtaining an oxide of the organic compound.

[0010] According to the method for producing an oxide of the present invention, an oxide of an organic compound can be obtained efficiently. The reason why the above effect is obtained is not clear, but is presumed as follows. In the method for producing an oxide of the present invention, when a dehydrogenation oxidation reaction of an organic compound is carried out, the Pt / Bi composite catalyst used in the reaction is charged together with the raw material, and the organic compound is dehydrogenated while the Pt / Bi composite catalyst is produced in the reaction system. When preparing catalysts such as the Pt / Bi composite catalyst used in conventional dehydrogenation reactions of organic compounds, a Pt and Bi composite catalyst is usually prepared by adding a reducing agent to a Pt ion source and a Bi ion source under alkaline conditions to precipitate Pt and Bi. However, since Bi segregates during this process, it is thought that there are few active structures that are effective in the dehydrogenation reactions of organic compounds, resulting in low catalytic activity. On the other hand, in the present invention, when Pt supported on a carrier is brought into contact with a Bi ion source under conditions where the minimum pH during the reaction is less than 7, Bi can be reduced and precipitated uniformly on the Pt even without a reducing agent, and many active structures effective in the dehydrogenative oxidation reaction of organic compounds can be formed, which is thought to be the reason for the high activity of the catalyst, although the reason is unclear. Furthermore, in the past, when the catalytic activity in the dehydrogenation oxidation reaction of organic compounds having hydroxyl groups or aldehyde groups was low, alkaline conditions were sometimes used to improve reactivity. However, in the method for producing an oxide of the present invention, the minimum pH during the reaction is less than 7, and the catalytic activity can be increased as described above, so that the production rate of the oxide of the organic compound can be improved without adding an alkaline agent. Furthermore, when performing dehydrogenation oxidation reactions under conventional alkaline conditions, as described above, an alkaline agent or the like is added to create alkaline conditions in the system, resulting in the by-production of a neutralized salt of the oxide. When a neutralized salt of the oxide is formed in the reaction system, the viscosity of the reaction solution increases and the reaction solution gels at a high oxide / water ratio compared to when only the oxide is present. Therefore, in conventional oxidation reactions under alkaline conditions, the reaction must be performed at a low oxide / water ratio and a low active ingredient concentration, making it difficult to increase productivity. In contrast, the oxide production method of the present invention can suppress the by-production of a neutralized salt of the oxide and inhibit the increase in viscosity and gelation of the reaction solution. This allows for efficient dehydrogenation oxidation reactions of organic compounds at a high active ingredient concentration and a high oxide / water ratio, thereby improving productivity. Furthermore, the generation of salt generated when extracting the oxide from the by-produced neutralized salt of the oxide can be suppressed, thereby reducing wastewater generation and environmental impact.

[0011] Furthermore, in the method for producing an oxide of the present invention, from the viewpoint of obtaining an oxide of an organic compound at a high production rate, it is preferable to accompany the preparation of a Pt / Bi composite catalyst. The reason why the preparation of a Pt / Bi composite catalyst is preferably accompanied is not clear, but is thought to be as follows. By mixing an organic compound in the presence of the Pt supported on the carrier and the Bi ion source, a dehydrogenation-oxidation reaction of the organic compound occurs. This generates a small amount of oxide of the organic compound, forming an oxide-containing solution. It is presumed that the Bi ion source dissolves, generating Bi ions, and Bi is reduced and precipitated on the Pt, thereby preparing a Pt / Bi composite catalyst in the system, which is more active than a Pt catalyst. It is also presumed that the preparation of the Pt / Bi composite catalyst promotes the dehydrogenation reaction of the organic compound, resulting in a high yield of the oxide of the organic compound. As described above, the method for producing an oxide of the present invention can prepare a catalyst simultaneously in the process for producing an oxide, and therefore does not require any separate equipment or process for producing the catalyst, making it possible to efficiently produce an oxide of an organic compound, and is therefore very advantageous in terms of production efficiency and production costs.

[0012] In this specification, unless otherwise specified, Pt means platinum, Bi means bismuth, and C means activated carbon. In addition, in this specification, unless otherwise specified, "%" means "mass %."

[0013] <Organic compounds with one primary hydroxyl group> The method for producing an oxide of the present invention is carried out by subjecting an organic compound having one primary hydroxyl group (hereinafter also simply referred to as an organic compound) to a dehydrogenation oxidation reaction. Examples of organic compounds having one primary hydroxyl group include aliphatic alcohols, polyoxyalkylene alkyl ethers, amide alcohols, and aromatic alcohols. From the viewpoint of hydrophilicity, at least one selected from aliphatic alcohols, polyoxyalkylene alkyl ethers, and amide alcohols is preferred, and at least one selected from aliphatic alcohols and polyoxyalkylene alkyl ethers is more preferred. The aliphatic alcohol or polyoxyalkylene alkyl ether is preferably one or more of those represented by the following general formula (1) or general formula (2).

[0014] R 1 OH (1) In general formula (1), R 1 is a monovalent aliphatic hydrocarbon group having 2 to 40 carbon atoms.

[0015] R 2 O-(AO) n -H (2) In general formula (2), R 2 represents a monovalent aliphatic hydrocarbon group having 2 to 40 carbon atoms, A represents an alkanediyl group having 2 to 4 carbon atoms, AO represents an alkyleneoxy group, and n is the average number of moles of alkyleneoxy groups added, which is 1 to 30.

[0016] R 1 From the viewpoint of reactivity, is preferably a linear or branched primary monovalent aliphatic hydrocarbon group, more preferably a linear or branched primary alkyl group or alkenyl group, and even more preferably a linear primary alkyl group.

[0017] R 1 The number of carbon atoms is not particularly limited, but may be 6 or more, 8 or more, 10 or more, or 12 or more, and from the viewpoint of reactivity, is preferably 36 or less, more preferably 22 or less, even more preferably 18 or less, and still more preferably 14 or less.

[0018] R 2 From the viewpoint of reactivity, is preferably a linear or branched primary aliphatic hydrocarbon group, more preferably a linear or branched primary alkyl group or alkenyl group, and even more preferably a linear primary alkyl group.

[0019] R 2 The number of carbon atoms is not particularly limited, but may be 6 or more, 8 or more, 10 or more, or 12 or more, and from the viewpoint of reactivity, is preferably 36 or less, more preferably 22 or less, even more preferably 18 or less, and still more preferably 14 or less.

[0020] From the viewpoint of reactivity, A is preferably an ethylene group or a propylene group, more preferably an ethylene group. Similarly, from the viewpoint of reactivity, AO is preferably an ethyleneoxy group (EO) or a propyleneoxy group (PO), more preferably an ethyleneoxy group (EO).

[0021] From the viewpoint of reactivity, n is preferably 3 or more, and preferably 25 or less, more preferably 20 or less, even more preferably 16 or less, and still more preferably 12 or less.

[0022] In the oxide manufacturing method of the present invention, the hydrophilicity of the organic compound affects reactivity, and the higher the hydrophilicity, the higher the reactivity between the Pt / Bi composite catalyst and the organic compound. That is, the higher the IOB value (Inorganic-Organic Balance Value) IV / OV, calculated from the Inorganic Value IV and the Organic Value OV of the organic conceptual diagram of the organic compound, the higher the reactivity. Therefore, from the viewpoint of high hydrophilicity, the organic compound is preferably a polyoxyalkylene alkyl ether, more preferably a polyoxyalkylene alkyl ether represented by the above general formula (2). From the viewpoint of reactivity, the IOB value based on the organic conceptual diagram of the organic compound is preferably 0.3 or more, more preferably 1 or more, and even more preferably 4 or more. The IOB value of the organic compound may be less than 5.

[0023] In the method for producing an oxide of the present invention, a carboxylic acid compound or a salt of a carboxylic acid compound can be obtained as an oxide by subjecting the organic compound to a dehydrogenation oxidation reaction. Carboxylic acid compounds or carboxylic acids compound Examples of the salts include carboxylic acid compounds or salts of carboxylic acid compounds obtained by subjecting the above-mentioned aliphatic alcohols or polyoxyalkylene alkyl ethers to a dehydrogenative oxidation reaction, and examples thereof include so-called ether carboxylates or salts thereof obtained by subjecting polyoxyalkylene alkyl ethers to an oxidation reaction.

[0024] <Pt supported on a carrier> The carrier used for the Pt supported on a carrier is preferably a carrier selected from titania, zirconia and activated carbon, from the viewpoint of carrying out the reaction under conditions of a pH of less than 7, and more preferably activated carbon. There are no particular limitations on the activated carbon, and any type of activated carbon can be used as long as it can adsorb and support Pt. Examples of activated carbon include vegetable activated carbon such as coconut shell activated carbon, mineral activated carbon such as coal-based activated carbon, and activated carbon made from pulp waste liquor, synthetic resin, and organic waste. There are also no particular limitations on the activation method, pore distribution, shape, etc. However, reactivity differs. Coal-based activated carbon is more highly active than vegetable activated carbon and is therefore preferable. On the other hand, vegetable activated carbon is more preferable than coal-based activated carbon in terms of strength to prevent crushing during filtration.

[0025] There are no particular restrictions on the particle size of Pt supported on the support, but from the viewpoint of increasing the amount of Pt supported, it is preferably 1 nm or more, more preferably 3 nm or more, and from the viewpoint of increasing the dispersibility of Pt on the support surface, it is preferably 20 nm or less, more preferably 15 nm or less, and even more preferably 10 nm or less.

[0026] The amount of Pt supported on the carrier, i.e., the amount of Pt supported relative to the total amount of carrier and Pt, is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, still more preferably 3% by mass or more, and even more preferably 5% by mass or more, from the viewpoint of the reactivity of the dehydrogenation reaction of organic compounds, and is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, from the viewpoint of improving the dispersibility of Pt on the carrier surface. Furthermore, Pt supported on a carrier can be prepared by known impregnation methods or precipitation methods, but commercially available products can also be used.

[0027] The charged amount of Pt supported on the carrier can be arbitrarily selected within the range in which a practical reaction rate can be obtained according to the reaction temperature or reaction pressure. However, when the reaction is carried out batchwise, from the viewpoint of reactivity, it is preferably 1 part by mass or more, more preferably 3 parts by mass or more, still more preferably 4 parts by mass or more, and preferably 10 parts by mass or less, more preferably 8 parts by mass or less, still more preferably 6 parts by mass or less, based on 100 parts by mass of the organic compound.

[0028] <Bi ion source> The Bi ion source is preferably water-insoluble from the viewpoint of improving the catalytic activity of the produced Pt / Bi composite catalyst and efficiently obtaining the oxide. The Bi ion source is preferably at least one selected from bismuth nitrate pentahydrate (Bi(NO3)3·5H2O), bismuth oxide (Bi2O3), basic bismuth carbonate ((BiO)2CO3), and bismuth hydroxide (Bi(OH)3). Depending on the Bi ion source used, the catalytic activity of the obtained Pt / Bi composite catalyst varies. In the present invention, when bismuth oxide is used as the Bi ion source, a Pt / Bi composite catalyst with high catalytic activity can be obtained, and the oxide of the organic compound can be efficiently obtained. Therefore, bismuth oxide is suitable as the Bi ion source.

[0029] The charged amount of the Bi ion source is preferably 0.01 part by mass or more, more preferably 0.03 part by mass or more, still more preferably 0.05 part by mass or more, and preferably 1 part by mass or less, more preferably 0.5 part by mass or less, still more preferably 0.3 part by mass or less, based on 100 parts by mass of the organic compound, from the viewpoints of the production efficiency of the catalyst and the production efficiency of the oxide of the organic compound.

[0030] In the method for producing an oxide of the present invention, the mass ratio (atomic ratio) of the amount of Bi charged to Pt, Bi / Pt, is preferably 0.05 or more, more preferably 0.1 or more, from the viewpoint of improving the productivity of the oxidation reaction product, and is preferably 2.0 or less, more preferably 1.8 or less, even more preferably 1.5 or less, still more preferably 1.4 or less, still more preferably 1.2 or less, and still more preferably 1.0 or less.

[0031] When bismuth oxide is used as a Bi ion source, the reactivity of the Pt / Bi composite catalyst prepared varies depending on the amount of bismuth oxide added. Adding even a small amount of bismuth oxide improves the reactivity of the Pt / Bi composite catalyst prepared. The preferred amount of bismuth oxide added per 100 parts by mass of the organic compound is the same as the preferred amount of the Bi ion source described above.

[0032] <Water> The method for producing an oxide of the present invention is carried out in the presence of water, and preferred examples of water include ion-exchanged water, distilled water, and pure water.

[0033] The amount of water used is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and preferably 35 parts by mass or less, more preferably 30 parts by mass or less, per 100 parts by mass of the organic compound, from the viewpoints of improving productivity of the oxide of the organic compound and suppressing an increase in viscosity of the liquid phase.

[0034] The amount of water used is the total amount of the water charged, the water content of the Pt supported on the carrier, and the water content of the Bi ion source.

[0035] <Reaction conditions> (pH during reaction) In the oxide production method of the present invention, the minimum pH during the reaction is less than 7. By keeping the minimum pH during the reaction less than 7, the reaction system can be made acidic, the Bi ion source dissolves, Bi ions are easily produced, and Bi is prevented from precipitating independently from the Bi ions on a carrier such as activated carbon, allowing Bi to be reduced and precipitated near Pt, creating a highly active structure. This is thought to significantly improve the reactivity of the reaction for producing a highly active Pt / Bi composite catalyst and the dehydrogenative oxidation reaction of organic compounds.

[0036] In the method for producing an oxide of the present invention, the minimum pH during the reaction can be adjusted to less than 7 by not adding an alkaline agent or the like to the reaction system, since the organic compound undergoes a dehydrogenation oxidation reaction to produce the oxide.

[0037] In the method for producing an oxide of the present invention, when Bi oxide is used as the Bi ion source, the pH is alkaline when the raw materials are charged, but as the reaction progresses and the amount of oxide of the organic compound in the reaction system increases, it changes to an acidic pH. The minimum pH at the end of the reaction is preferably 6 or less, more preferably 5 or less, and even more preferably 4 or less, from the viewpoint of improving the production efficiency of the Pt / Bi composite catalyst and the production efficiency of the oxide of the organic compound, and is preferably 1 or more, more preferably 1.5 or more, and even more preferably 2 or more.

[0038] (Reaction temperature) The reaction temperature in the oxide production method of the present invention is preferably 50°C or higher, more preferably 60°C or higher, from the viewpoint of the reactivity of the reaction for producing a Pt / Bi composite catalyst and the dehydrogenative oxidation reaction of organic compounds, and is preferably 100°C or lower, more preferably 90°C or lower, and even more preferably 85°C or lower, from the viewpoint of the equipment load.

[0039] (oxygen-containing gas) In the method for producing an oxide of the present invention, it is preferable to supply oxygen into the reaction system from the viewpoint of causing the organic compound to undergo a dehydrogenation oxidation reaction. Oxygen can be supplied by passing an oxygen-containing gas through the liquid phase. Examples of the oxygen-containing gas include oxygen gas and air. When a mixed gas containing oxygen is used, the gas used in combination with oxygen is preferably an inert gas such as helium, argon, or nitrogen, from the viewpoint of not affecting the activity. From the viewpoint of productivity of the oxide, the oxygen concentration in the oxygen-containing gas is preferably 10% by volume or more, more preferably 50% by volume or more, even more preferably 70% by volume or more, still more preferably 90% by volume or more, and even more preferably 100% by volume.

[0040] (reaction pressure) In the method for producing an oxide of the present invention, the reaction may be carried out under normal pressure or under increased pressure. From the viewpoint of reactivity, the reaction pressure is preferably 0.09 MPa or more, more preferably 0.10 MPa or more, in terms of absolute pressure, and from the viewpoint of equipment load, it is preferably 0.5 MPa or less, more preferably 0.2 MPa or less, and even more preferably 0.11 MPa or less. The reaction is preferably carried out under normal pressure.

[0041] <Oxide purification> The method for producing an oxide of the present invention may further include a step of purifying the oxide obtained after the completion of the dehydrogenation reaction of the organic compound. In the method for producing an oxide of the present invention, after the oxidation reaction of the organic compound is completed, for example, pressure filtration, reduced pressure filtration, etc. can be performed. Yes The Pt / Bi composite catalyst can be removed from the reaction solution containing the oxides of the organic compounds. In the method for producing an oxide of the present invention, an oxide of an organic compound can be obtained at a high production rate, and therefore, the reaction solution containing the oxide of the organic compound can be used as it is as a raw material for producing a cleaning agent, etc. If necessary, the reaction solution containing the oxide of the organic compound can be extracted, distilled, etc. to extract the organic compound. oxide of can also be obtained in high concentrations.

[0042] [Other methods for producing oxides] Another method for producing an oxide of the present invention is a method for producing an oxide, which comprises dehydrogenating an organic compound having one primary hydroxyl group in the presence of a Pt / Bi composite catalyst, a Bi ion source, and water under conditions where the minimum pH during the reaction is less than 7, to obtain an oxide of the organic compound. According to another method for producing an oxide of the present invention, an oxide of an organic compound can be obtained at a high production rate. In the other method for producing an oxide of the present invention, the Pt / Bi composite catalyst is the same as the Pt / Bi composite catalyst obtained by the above-mentioned method for producing an oxide or the Pt / Bi composite catalyst obtained by the method for producing a Pt / Bi catalyst described below.

[0043] Another method for producing the oxide of the present invention preferably involves the regeneration of the Pt / Bi composite catalyst. The reason why regeneration of the Pt / Bi composite catalyst is preferably accompanied is not clear, but is thought to be as follows. It is believed that when a Pt / Bi composite catalyst is repeatedly used in a method for producing an oxide of an organic compound, Bi gradually dissolves out, causing a change in the structure of the catalyst and a decrease in catalytic activity. In the other oxide production method of the present invention, by adding a Bi ion source together with the Pt / Bi composite catalyst, Bi is reduced and precipitated on the Pt / Bi composite catalyst, which is presumably responsible for regenerating the Pt / Bi composite catalyst. Furthermore, it is presumed that the regeneration of the Pt / Bi composite catalyst promotes the dehydrogenation reaction of the organic compound, resulting in the production of the oxide of the organic compound in high yield. As described above, the other method for producing an oxide of the present invention can accompany the regeneration of the Pt / Bi composite catalyst within the oxide production process, and therefore does not require any separate equipment or process for catalyst regeneration, making it possible to efficiently produce an oxide of an organic compound, which has significant advantages in terms of production efficiency and production costs.

[0044] Furthermore, in the oxide production method of the present invention and other oxide production methods, from the viewpoint of efficiently regenerating the Pt / Bi composite catalyst and improving the yield of the oxide of the organic compound, it is preferable to add a Bi ion source at the start of or during the dehydrogenative oxidation reaction of the organic compound, and it is more preferable to add the Bi ion source during the reaction. Adding a Bi ion source to the system at the start of the reaction can help to suppress deterioration of the Pt / Bi composite catalyst and improve the yield of the oxide of the organic compound. Furthermore, by adding a Bi ion source to the system during the reaction in accordance with the deterioration status of the Pt / Bi composite catalyst, the Pt / Bi composite catalyst can be regenerated. This makes it possible to suppress a decrease in the efficiency of the dehydrogenation oxidation reaction of organic compounds and to easily improve the yield of oxides of organic compounds. Furthermore, this could be a method for regenerating high-performance Pt / Bi composite catalysts without the need to re-prepare them, addressing the issue of Bi elution and reduced catalytic activity when catalysts are recycled.

[0045] [Method for producing Pt / Bi composite catalyst] The method for producing a Pt / Bi composite catalyst of the present invention involves mixing Pt supported on a carrier with a Bi ion source in the presence of an organic compound having one primary hydroxyl group and water, and reacting them under conditions where the minimum pH during the reaction is less than 7.

[0046] According to the method for producing a Pt / Bi composite catalyst of the present invention, it is possible to produce a catalyst that exhibits high activity in the dehydrogenation reaction of organic compounds. The reason why the above effect is obtained is not clear, but is presumed as follows. Conventional catalysts, such as Pt / Bi composite catalysts, are typically prepared by precipitating Pt and Bi by adding a reducing agent to Pt and Bi ion sources under alkaline conditions. However, this method results in segregation of Bi, and the resulting composite catalyst has few active structures effective in the dehydrogenation of organic compounds, resulting in low catalytic activity. On the other hand, in the method for producing the Pt / Bi composite catalyst of the present invention, Pt supported on a carrier such as a Pt / C catalyst is brought into contact with Bi ions under conditions where the minimum pH during the reaction is less than 7, and Bi is uniformly reduced and precipitated on the Pt without the addition of a reducing agent, forming many active structures that are effective in the dehydrogenation oxidation reaction of organic compounds. As a result, it is presumed that the activity of the catalyst can be increased.

[0047] Furthermore, in the method for producing a Pt / Bi composite catalyst of the present invention, from the viewpoint of producing a catalyst exhibiting high activity, the dehydrogenation-oxidation reaction of an organic compound having one primary hydroxyl group is preferably accompanied in the reaction system, and more preferably the dehydrogenation-oxidation reaction of the organic compound is promoted. The reason why the dehydrogenation reaction of the organic compound is preferably accompanied, and more preferably the reaction is accelerated, is not clear, but is thought to be as follows. By mixing Pt supported on a carrier with a Bi ion source in the presence of the organic compound, a dehydrogenation-oxidation reaction of the organic compound occurs. This generates a small amount of oxide of the organic compound, forming an oxide-containing solution. The Bi ion source dissolves, generating Bi ions. Bi is reduced and precipitated on the Pt, producing a Pt / Bi composite catalyst in the system, which is more active than a Pt catalyst. It is presumed that this accelerates the dehydrogenation reaction of the organic compound, resulting in a high yield of the oxide of the organic compound. From the above, it is believed that it is possible to produce a catalyst simultaneously in the process of producing an oxide, which does not require any separate equipment or process for producing a catalyst, and it is possible to efficiently produce an oxide of an organic compound, which has great advantages in terms of production efficiency and production costs.

[0048] According to the method for producing a Pt / Bi composite catalyst of the present invention, a carboxylic acid compound or a salt of a carboxylic acid compound, which is an oxide of the organic compound, can be obtained during the production of the Pt / Bi composite catalyst. Examples of the carboxylic acid compound or the salt of the carboxylic acid compound include the carboxylic acid compound or the salt of the carboxylic acid compound obtained by subjecting the above-mentioned aliphatic alcohol or polyoxyalkylene alkyl ether to a dehydrogenative oxidation reaction. Examples of the carboxylic acid compound include fatty acids obtained by dehydrogenation oxidation of aliphatic alcohols, and ether carboxylates obtained by dehydrogenation oxidation of polyoxyalkylene alkyl ethers. Examples of the salts of carboxylic acid compounds include neutral salts of the above fatty acids or ether carboxylates with alkali metal hydroxides such as sodium and potassium.

[0049] In the method for producing a Pt / Bi composite catalyst of the present invention, preferred examples of the organic compound having one primary hydroxyl group include aliphatic alcohols and polyoxyalkylene alkyl ethers, and those listed as organic compounds having one primary hydroxyl group in the above-mentioned method for producing an oxide of the present invention can be suitably used. The organic compound having one primary hydroxyl group is preferably a highly hydrophilic organic compound from the viewpoint of the rate of oxide production. The organic compound having one primary hydroxyl group is preferably a polyoxyalkylene alkyl ether, more preferably a polyoxyalkylene alkyl ether represented by the above general formula (2).

[0050] In the method for producing a Pt / Bi composite catalyst of the present invention, the reaction may be carried out in the presence of an oxide of the organic compound. Examples of the oxide of the organic compound include carboxylic acid compounds or salts of carboxylic acid compounds in which the hydroxyl groups of the organic compounds exemplified in the method for producing an oxide of the present invention are oxidized.

[0051] Examples of Pt supported on a carrier used in the method for producing a Pt / Bi composite catalyst of the present invention include the same Pt ​​supported on a carrier used in the method for producing an oxide of the present invention, and the preferred ranges are also the same. The Pt carrier used in the method for producing a Pt / Bi composite catalyst of the present invention is preferably activated carbon. Examples of activated carbon include the same activated carbons as those used in the method for producing an oxide of the present invention, and the preferred ranges are also the same.

[0052] In the method for producing a Pt / Bi composite catalyst of the present invention, the Bi ion source is preferably water-insoluble, from the viewpoint of improving the catalytic activity of the produced Pt / Bi composite catalyst. Examples of the Bi ion source include the same Bi ion source as that used in the method for producing an oxide of the present invention.

[0053] The method for producing a Pt / Bi composite catalyst of the present invention is carried out in the presence of water. Examples of water include the same water as used in the method for producing an oxide of the present invention, and the preferred ranges are also the same.

[0054] In the method for producing a Pt / Bi composite catalyst of the present invention, the minimum pH during the reaction is less than 7. By keeping the minimum pH during the reaction less than 7, the reaction system can be made acidic, the Bi ion source dissolves, Bi ions are easily produced, and the precipitation of Bi alone from the Bi ions onto a support such as activated carbon is suppressed, allowing Bi to be reduced and precipitated near Pt, creating a highly active structure. This is thought to significantly improve the reactivity of the reaction for producing a highly active Pt / Bi composite catalyst and the dehydrogenative oxidation reaction of organic compounds. The pH conditions during the reaction are the same as the preferred range of pH during the reaction in the method for producing an oxide of the present invention.

[0055] The reaction temperature in the method for producing a Pt / Bi composite catalyst of the present invention is the same as that in the method for producing an oxide of the present invention.

[0056] In the method for producing a Pt / Bi composite catalyst of the present invention, it is preferable to supply oxygen into the reaction system from the viewpoint of dehydrogenation oxidation of organic compounds. The supply of oxygen can be carried out by passing an oxygen-containing gas through the liquid phase. Examples of the oxygen-containing gas include the same oxygen-containing gases as those used in the method for producing an oxide of the present invention, and the preferred ranges are also the same.

[0057] The reaction pressure in the method for producing a Pt / Bi composite catalyst of the present invention is the same as that in the method for producing an oxide of the present invention.

[0058] <Catalyst recovery> The catalyst produced by the method for producing a Pt / Bi composite catalyst of the present invention can be recovered by separating it from the reaction solution, for example, by pressure filtration, vacuum filtration, or the like. The recovered Pt / Bi composite catalyst may be washed, but can be used as a catalyst for the dehydrogenation oxidation reaction of organic compounds without washing. The catalyst produced by the method for producing a Pt / Bi composite catalyst of the present invention can be recovered and reused as a catalyst for the dehydrogenation oxidation reaction of the above-mentioned organic compounds.

[0059] [Other methods for producing Pt / Bi composite catalyst] Another method for producing the Pt / Bi composite catalyst of the present invention is a method for producing the Pt / Bi composite catalyst by mixing the Pt / Bi composite catalyst and a Bi ion source in the presence of an organic compound having one primary hydroxyl group and water, and reacting them under conditions where the minimum pH during the reaction is less than 7. According to another method for producing a Pt / Bi composite catalyst of the present invention, a catalyst exhibiting high activity in the dehydrogenation reaction of organic compounds can be produced. In the other method for producing a Pt / Bi composite catalyst of the present invention, the Pt / Bi composite catalyst is the same as the Pt / Bi composite catalyst described above or the Pt / Bi composite catalyst obtained by the oxide production method described below.

[0060] In another method for producing the Pt / Bi composite catalyst of the present invention, a Bi ion source is preferably added at the start of the reaction or during the reaction to regenerate the Pt / Bi composite catalyst, and more preferably a Bi ion source is added during the reaction to regenerate the Pt / Bi composite catalyst. Adding a Bi ion source to the system at the start of the reaction can suppress the deterioration of the Pt / Bi composite catalyst and improve the yield of the oxide of the organic compound. Furthermore, by adding a Bi ion source to the system during the reaction, the Pt / Bi composite catalyst can be regenerated, which prevents a decrease in the efficiency of the dehydrogenation reaction of organic compounds and improves the yield of the oxides of the organic compounds.

[0061] The reason why the addition of a Bi ion source at the start of or during the reaction is accompanied by regeneration of the Pt / Bi composite catalyst is not clear, but is thought to be as follows. It is believed that when a Pt / Bi composite catalyst is repeatedly used in a method for producing an oxide of an organic compound, Bi gradually dissolves out, causing a change in the structure of the catalyst and a decrease in catalytic activity. In another method for producing the Pt / Bi composite catalyst of the present invention, adding a Bi ion source together with the Pt / Bi composite catalyst reduces and deposits Bi on the Pt / Bi composite catalyst, presumably regenerating the Pt / Bi composite catalyst. Furthermore, it is presumed that the regeneration of the Pt / Bi composite catalyst promotes the dehydrogenation reaction of the organic compound, resulting in a high yield of the oxide of the organic compound. As described above, the other method for producing a Pt / Bi composite catalyst of the present invention can regenerate the Pt / Bi composite catalyst during the oxide production process, so that no separate equipment or process for catalyst regeneration is required, and the Pt / Bi composite catalyst can be produced efficiently, which has significant advantages in terms of production efficiency and production costs.

[0062] [Oxides of organic compounds] The oxides of organic compounds obtained by the oxide production method and Pt / Bi composite catalyst production method of the present invention can be used in a wide range of fields, such as detergents, fabric softeners, wetting agents, dyeing aids, etc. Furthermore, because they have excellent foaming and detergency properties and low skin irritation, they can be suitably used in products that come into prolonged contact with human skin, such as shampoos, body washes, kitchen detergents, cosmetic compositions, and fragrances.

[0063] According to the method for producing an oxide and the method for producing a Pt / Bi composite catalyst of the present invention, an oxide of an organic compound can be obtained at a high production rate. In the method for producing an oxide and the method for producing a Pt / Bi composite catalyst of the present invention, the production rate of an oxide of an organic compound after 24 hours of reaction is preferably 75% or more, more preferably 77% or more, even more preferably 80% or more, and still more preferably 83% or more. Furthermore, the production rate of the oxide of the organic compound after 3 hours of reaction is preferably 20% or more, more preferably 25% or more, and even more preferably 30% or more. In the present invention, the production rate of an oxide of an organic compound can be determined in the same manner as the calculation method for the production rate of a carboxylic acid compound in the examples described later.

[0064] [Pt / Bi composite catalyst] The Pt / Bi composite catalyst of the present invention can be obtained by the above-mentioned method for producing an oxide and method for producing a Pt / Bi composite catalyst of the present invention. The Pt / Bi composite catalyst of the present invention is suitable for use in a reaction for producing an oxide of an organic compound by dehydrogenating an organic compound having one primary hydroxyl group as described above. Specifically, the present invention also relates to a method for producing an oxide, in which an organic compound having one primary hydroxyl group is dehydrogenated in the presence of the Pt / Bi composite catalyst to obtain an oxide of the organic compound. The method for producing an oxide of the present invention preferably includes water as a solvent, and supplies oxygen to a composition containing an organic compound having one primary hydroxyl group in the presence of the Pt / Bi composite catalyst to dehydrogenate the organic compound having one primary hydroxyl group.

[0065] From the viewpoint of improving the productivity of the oxidation reaction product, the amount of Bi supported in the Pt / Bi composite catalyst is preferably 0.01 mass% or more, more preferably 0.5 mass% or more, and preferably 10 mass% or less, more preferably 5 mass% or less, even more preferably 3.5 mass% or less, and still more preferably 2.5 mass% or less.

[0066] In the Pt / Bi composite catalyst of the present invention, the mass ratio (atomic ratio) of Bi to Pt, Bi / Pt, is preferably 0.05 or more, more preferably 0.1 or more, from the viewpoint of improving the productivity of the oxidation reaction product, and is preferably 2.0 or less, more preferably 1.5 or less, even more preferably 1.0 or less, and still more preferably 0.5 or less.

[0067] In relation to the above-described embodiments, the present invention further discloses the following methods for producing oxides and Pt / Bi composite catalysts. <1> A method for producing an oxide, comprising dehydrogenating an organic compound having one primary hydroxyl group in the presence of Pt supported on a carrier, a Bi ion source, and water, under conditions where the minimum pH during the reaction is less than 7, to obtain an oxide of the organic compound. <2> A method for producing an oxide, comprising dehydrogenating an organic compound having one primary hydroxyl group in the presence of a Pt / Bi composite catalyst, a Bi ion source, and water under conditions where the minimum pH during the reaction is less than 7, to obtain an oxide of the organic compound. <3> This involves the preparation of a Pt / Bi composite catalyst. <1> or <2> A method for producing the oxide described in <4> The Bi ion source is water-insoluble. <1> ~ <3> 1. A method for producing an oxide according to any one of the preceding claims. <5> The Bi ion source is bismuth oxide. <1> ~ <4> 1. A method for producing an oxide according to any one of the preceding claims. <6> the amount of the Bi ion source charged is preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, even more preferably 0.05 parts by mass or more, and is preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, even more preferably 0.3 parts by mass or less, relative to 100 parts by mass of the organic compound; <1> ~ <5> 1. A method for producing an oxide according to any one of the preceding claims. <7> The mass ratio (atomic ratio) of the amount of Bi charged to the amount of Pt charged, Bi / Pt, is preferably 0.05 or more, more preferably 0.1 or more, and is preferably 2.0 or less, more preferably 1.8 or less, even more preferably 1.5 or less, still more preferably 1.4 or less, still more preferably 1.2 or less, and still more preferably 1.0 or less. <1> ~ <6> 1. A method for producing an oxide according to any one of the preceding claims.

[0068] <8> The organic compound is an aliphatic alcohol or a polyoxyalkylene alkyl ether. <1> ~ <7> 1. A method for producing an oxide according to any one of the preceding claims. <9> The aliphatic alcohol or polyoxyalkylene alkyl ether is preferably one or more of those represented by the following general formula (1) or (2): <8> A method for producing the oxide described in R 1OH (1) In general formula (1), R 1 is a monovalent aliphatic hydrocarbon group having 2 to 40 carbon atoms. R 2 O-(AO) n -H (2) In general formula (2), R 2 represents a monovalent aliphatic hydrocarbon group having 2 to 40 carbon atoms, A represents an alkanediyl group having 2 to 4 carbon atoms, AO represents an alkyleneoxy group, and n is the average number of moles of alkyleneoxy groups added, which is 1 to 30. <10> R in the general formula (1) 1 is preferably a linear or branched primary monovalent aliphatic hydrocarbon group, more preferably a linear or branched primary alkyl or alkenyl group, and even more preferably a linear primary alkyl group; <9> A method for producing the oxide described in <11> R in the general formula (1) 1 has preferably 6 or more, more preferably 8 or more, even more preferably 10 or more, still more preferably 12 or more carbon atoms, and is preferably 36 or less, more preferably 22 or less, even more preferably 18 or less, still more preferably 14 or less carbon atoms. <9> or <10> A method for producing the oxide described in <12> R in the general formula (2) 2 is preferably a linear or branched primary aliphatic hydrocarbon group, more preferably a linear or branched primary alkyl or alkenyl group, even more preferably a linear primary alkyl group; <9> ~ <11> 1. A method for producing an oxide according to any one of the preceding claims. <13> R in the general formula (2) 2 has preferably 6 or more, more preferably 8 or more, even more preferably 10 or more, still more preferably 12 or more carbon atoms, and is preferably 36 or less, more preferably 22 or less, even more preferably 18 or less, still more preferably 14 or less carbon atoms; <9> ~ <12> 1. A method for producing an oxide according to any one of the preceding claims. <14> In the general formula (2), A is preferably an ethylene group or a propylene group, more preferably an ethylene group. <9> ~ <13> 1. A method for producing an oxide according to any one of the preceding claims. <15> AO in the general formula (2) is preferably an ethyleneoxy group (EO) or a propyleneoxy group (PO), more preferably an ethyleneoxy group (EO). <9> ~ <14> 1. A method for producing an oxide according to any one of the preceding claims. <16> n in the general formula (2) is preferably 3 or more, and preferably 25 or less, more preferably 20 or less, even more preferably 16 or less, and still more preferably 12 or less. <9> ~ <15> 1. A method for producing an oxide according to any one of the preceding claims. <17> The organic compound is preferably a polyoxyalkylene alkyl ether, more preferably a polyoxyalkylene alkyl ether represented by the general formula (2). <9> ~ <16> 1. A method for producing an oxide according to any one of the preceding claims.

[0069] <18> the oxide of the organic compound is a carboxylic acid compound or a salt of a carboxylic acid compound; <1> ~ <17> 1. A method for producing an oxide according to any one of the preceding claims. <19> The carboxylic acid compound or the carboxylic acid compound is an ether carboxylate or a salt thereof obtained by subjecting a polyoxyalkylene alkyl ether to an oxidation reaction, <18> A method for producing the oxide described in <20> The carrier is activated carbon. <1> ~ <19> 1. A method for producing an oxide according to any one of the preceding claims. <21> The particle size of the Pt supported on the carrier is preferably 1 nm or more, more preferably 3 nm or more, and is preferably 20 nm or less, more preferably 15 nm or less, and even more preferably 10 nm or less. <1> ~ <20> 1. A method for producing an oxide according to any one of the preceding claims. <22> The amount of Pt supported on the support, i.e., the amount of Pt supported relative to the total amount of the support and Pt, is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, still more preferably 3% by mass or more, still more preferably 5% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, and still more preferably 10% by mass or less. <1> ~ <21> 1. A method for producing an oxide according to any one of the preceding claims. <23> The amount of Pt supported on the carrier is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and even more preferably 4 parts by mass or more, and is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 6 parts by mass or less, relative to 100 parts by mass of the organic compound. <1> ~ <22> 1. A method for producing an oxide according to any one of the preceding claims. <24> The amount of water is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and preferably 35 parts by mass or less, more preferably 30 parts by mass or less, relative to 100 parts by mass of the organic compound. <1> ~ <23> 1. A method for producing an oxide according to any one of the preceding claims.

[0070] <25> No alkaline agents are added to the reaction system. <1> ~ <24> 1. A method for producing an oxide according to any one of the preceding claims. <26> The minimum pH value at the end of the reaction in the method for producing an oxide is preferably 6 or less, more preferably 5 or less, even more preferably 4 or less, and is preferably 1 or more, more preferably 1.5 or more, even more preferably 2 or more. <1> ~ <25> 1. A method for producing an oxide according to any one of the preceding claims. <27> The reaction temperature in the method for producing the oxide is preferably 50°C or higher, more preferably 60°C or higher, and preferably 100°C or lower, more preferably 90°C or lower, and even more preferably 85°C or lower. <1> ~ <26> 1. A method for producing an oxide according to any one of the preceding claims. <28> In the method for producing an oxide, it is preferable to supply oxygen into the reaction system. <1> ~ <27> 1. A method for producing an oxide according to any one of the preceding claims. <29> The supply of oxygen is carried out by passing an oxygen-containing gas through the liquid phase; <28> A method for producing the oxide described in <30> The oxygen-containing gas is oxygen gas or air. <29> A method for producing the oxide described in <31> The oxygen concentration in the oxygen-containing gas is preferably 10% by volume or more, more preferably 50% by volume or more, even more preferably 70% by volume or more, still more preferably 90% by volume or more, and even more preferably 100% by volume. <30> or <31> A method for producing the oxide described in <32> In the method for producing an oxide, the reaction pressure is, in absolute pressure, preferably 0.09 MPa or more, more preferably 0.10 MPa or more, and preferably 0.5 MPa or less, more preferably 0.2 MPa or less, and even more preferably 0.11 MPa or less. <1> ~ <31> 1. A method for producing an oxide according to any one of the preceding claims. <33> In the method for producing an oxide, the reaction is preferably carried out under normal pressure. <1> ~ <32> 1. A method for producing an oxide according to any one of the preceding claims.

[0071] <34> adding a Bi ion source at the start of or during the dehydrogenation oxidation reaction; <1> ~ <33> 1. A method for producing an oxide according to any one of the preceding claims. <35> After the dehydrogenation oxidation reaction of the organic compound is completed, the obtained oxide is further purified. <1> ~ <34> 1. A method for producing an oxide according to any one of the preceding claims. <36> In the step of purifying the obtained oxide, after the oxidation reaction of the organic compound is completed, the Pt / Bi composite catalyst is removed from the reaction solution containing the oxide of the organic compound by pressure filtration or vacuum filtration. <35> A method for producing the oxide described in

[0072] <37> A method for producing a Pt / Bi composite catalyst is described, in which Pt supported on a carrier and a Bi ion source are mixed in the presence of an organic compound having one primary hydroxyl group and water, and the mixture is reacted under conditions where the minimum pH during the reaction is less than 7. <38> a Pt / Bi composite catalyst and a Bi ion source are mixed in the presence of an organic compound having one primary hydroxyl group and water, and the mixture is reacted under conditions where the minimum pH during the reaction is less than 7; Method for producing Pt / Bi composite catalyst. <39> A Bi ion source is added at the start of the reaction or during the reaction to regenerate the Pt / Bi composite catalyst. <38> 2. A method for producing a Pt / Bi composite catalyst according to claim 1. <40> The dehydrogenation reaction of the organic compound is accompanied by <37> ~ <39> 2. A method for producing the Pt / Bi composite catalyst according to claim 1.

[0073] <41> The organic compound is an aliphatic alcohol or a polyoxyalkylene alkyl ether. <37> ~ <40> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <42> The aliphatic alcohol or polyoxyalkylene alkyl ether is preferably one or more of those represented by the following general formula (1) or (2): <37> ~ <41> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. R 1 OH (1) In general formula (1), R 1 is a monovalent aliphatic hydrocarbon group having 2 to 40 carbon atoms. R 2 O-(AO) n -H (2) In general formula (2), R 2 represents a monovalent aliphatic hydrocarbon group having 2 to 40 carbon atoms, A represents an alkanediyl group having 2 to 4 carbon atoms, AO represents an alkyleneoxy group, and n is the average number of moles of alkyleneoxy groups added, which is 1 to 30. <43> R in the above general formula (1) 1 is preferably a linear or branched primary monovalent aliphatic hydrocarbon group, more preferably a linear or branched primary alkyl or alkenyl group, and even more preferably a linear primary alkyl group; <42> A method for producing a Pt / Bi composite catalyst using the oxide described in 1. <44> R in the general formula (1) 1 has preferably 6 or more, more preferably 8 or more, even more preferably 10 or more, still more preferably 12 or more carbon atoms, and is preferably 36 or less, more preferably 22 or less, even more preferably 18 or less, still more preferably 14 or less carbon atoms. <42> or <43> 2. A method for producing the Pt / Bi composite catalyst according to claim 1. <45> R in the general formula (2) 2 is preferably a linear or branched primary aliphatic hydrocarbon group, more preferably a linear or branched primary alkyl or alkenyl group, even more preferably a linear primary alkyl group; <42> ~ <44> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <46> R in the general formula (2) 2 has preferably 6 or more, more preferably 8 or more, even more preferably 10 or more, still more preferably 12 or more carbon atoms, and is preferably 36 or less, more preferably 22 or less, even more preferably 18 or less, still more preferably 14 or less carbon atoms; <42> ~ <45> 2. A method for producing the Pt / Bi composite catalyst according to claim 1. <47> In the general formula (2), A is preferably an ethylene group or a propylene group, more preferably an ethylene group. <42> ~ <46> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <48> AO in the general formula (2) is preferably an ethyleneoxy group (EO) or a propyleneoxy group (PO), more preferably an ethyleneoxy group (EO). <42> ~ <47> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <49> In the general formula (2), n is preferably 3 or more and preferably 25 or less, more preferably 20 or less, even more preferably 16 or less, and still more preferably 12 or less. <42> ~ <48> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <50> The organic compound is preferably a polyoxyalkylene alkyl ether, more preferably a polyoxyalkylene alkyl ether represented by the general formula (2). <42> ~ <49> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims.

[0074] <51> The reaction is further carried out in the presence of an oxide of the organic compound. <37> ~ <50> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <52> the oxide of the organic compound is a carboxylic acid compound or a salt of a carboxylic acid compound; <51> 2. A method for producing the Pt / Bi composite catalyst according to claim 1. <53> the carboxylic acid compound or the salt of the carboxylic acid compound is any one of a fatty acid obtained by dehydrogenative oxidation of an aliphatic alcohol, an ether carboxylate obtained by dehydrogenative oxidation of a polyoxyalkylene alkyl ether, and a neutral salt of any one of these with an alkali metal hydroxide such as sodium or potassium; <52> 2. A method for producing the Pt / Bi composite catalyst according to claim 1.

[0075] <54> The Bi ion source is water-insoluble. <37> ~ <53> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <55> The Bi ion source is bismuth oxide. <37> ~ <54> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <56> the amount of the Bi ion source charged is preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, even more preferably 0.05 parts by mass or more, and is preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, even more preferably 0.3 parts by mass or less, relative to 100 parts by mass of the organic compound; <37> ~ <55> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <57> The mass ratio (atomic ratio) of the amount of Bi charged to the amount of Pt charged, Bi / Pt, is preferably 0.05 or more, more preferably 0.1 or more, and is preferably 2.0 or less, more preferably 1.8 or less, even more preferably 1.5 or less, still more preferably 1.4 or less, still more preferably 1.2 or less, and still more preferably 1.0 or less. <37> ~ <56> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims.

[0076] <58> The carrier is activated carbon. <37> ~ <57> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <59> The particle size of the Pt supported on the carrier is preferably 1 nm or more, more preferably 3 nm or more, and is preferably 20 nm or less, more preferably 15 nm or less, and even more preferably 10 nm or less. <37> ~ <58> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <60> The amount of Pt supported on the support, i.e., the amount of Pt supported relative to the total amount of the support and Pt, is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, still more preferably 3% by mass or more, still more preferably 5% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, and still more preferably 10% by mass or less. <37> ~ <59> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <61> The amount of Pt supported on the carrier is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and even more preferably 4 parts by mass or more, and is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 6 parts by mass or less, relative to 100 parts by mass of the organic compound. <37> ~ <60> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims.

[0077] <62> The amount of water is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and preferably 35 parts by mass or less, more preferably 30 parts by mass or less, relative to 100 parts by mass of the organic compound. <37> ~ <61> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims.

[0078] <63> In the method for producing a Pt / Bi composite catalyst, the minimum pH at the end of the reaction is preferably 6 or less, more preferably 5 or less, and even more preferably 4 or less, and is preferably 1 or more, more preferably 1.5 or more, and even more preferably 2 or more. <37> ~ <62> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <64> No alkaline agents are added to the reaction system. <37> ~ <63> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <65> The reaction temperature in the method for producing the Pt / Bi composite catalyst is preferably 50°C or higher, more preferably 60°C or higher, and preferably 100°C or lower, more preferably 90°C or lower, and even more preferably 85°C or lower. <37> ~ <64> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <66> In the method for producing a Pt / Bi composite catalyst, it is preferable to supply oxygen into the reaction system. <37> ~ <65> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <67> The supply of oxygen is carried out by passing an oxygen-containing gas through the liquid phase; <66> 2. A method for producing the Pt / Bi composite catalyst according to claim 1. <68> The oxygen-containing gas is oxygen gas or air. <67> 2. A method for producing the Pt / Bi composite catalyst according to claim 1. <69> The oxygen concentration in the oxygen-containing gas is preferably 10% by volume or more, more preferably 50% by volume or more, even more preferably 70% by volume or more, still more preferably 90% by volume or more, and even more preferably 100% by volume. <67> or <68> 2. A method for producing the Pt / Bi composite catalyst according to claim 1. <70> In the method for producing a Pt / Bi composite catalyst, the reaction pressure is, in absolute pressure, preferably 0.09 MPa or more, more preferably 0.10 MPa or more, and preferably 0.5 MPa or less, more preferably 0.2 MPa or less, and even more preferably 0.11 MPa or less. <37> ~ <69> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <71> In the method for producing a Pt / Bi composite catalyst, the reaction is preferably carried out under normal pressure. <37> ~ <70> 1. A method for producing the Pt / Bi composite catalyst according to any one of the preceding claims. <72> <37> ~ <71> 1. A method for producing an oxide, comprising: subjecting an organic compound to a dehydrogenative oxidation reaction in the presence of a Pt / Bi composite catalyst obtained by the method for producing a Pt / Bi composite catalyst according to any one of 1 to 5, to obtain an oxide of the organic compound. [Example]

[0079] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Each property value was measured and evaluated by the following methods.

[0080] [Pt / Bi composite catalyst and production of carboxylic acid compounds] Example 1 A 500 mL five-neck flask equipped with a reflux tube, a dissolved oxygen concentration meter (METTLER TOLEDO), a mechanical stirrer (IWAKI, equipped with a glass stirring rod fitted with a crescent-shaped stirring blade (blade width 7.5 cm × height 2.2 cm × thickness 0.4 cm)), a glass temperature-controlling holder, and a glass tube for gas introduction was charged with the following raw materials. (raw materials, etc.) Organic compound: 100 parts by mass (200 g) of AE1 (polyoxyalkylene alkyl ether in which an average of 3.6 mol of ethylene oxide is added to 1 mol of lauryl alcohol) was charged. Pt supported on a carrier: 5% Pt / C (manufactured by Evonik, C: charcoal, moisture content: 59.9% by mass): 4.90 parts by mass (24.45 g) of solid content excluding moisture was charged. Bi ion source: 0.11 parts by mass (0.219 g) of bismuth oxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was charged. Water: Ion-exchanged water (35.35 g) was added so that the total weight of the water content of the 5% Pt / C was 25 parts by mass.

[0081] Next, under a nitrogen flow, the five-neck flask was immersed in a water bath, and the charged raw materials were heated to 80° C. while being stirred at 600 rpm. After the temperature reached 80° C., the nitrogen flow was stopped, and oxygen was bubbled through the charged raw materials at 60 mL / min., and the reaction was carried out under normal pressure for 24 hours.

[0082] The reaction was carried out in several divided intervals every few hours. When the reaction was temporarily stopped, the reaction temperature was lowered to room temperature, oxygen bubbling was stopped, nitrogen was introduced, and the reaction was stopped by maintaining the dissolved oxygen concentration at 0 ppm for 1 hour. When the reaction was restarted, the temperature was raised to 80°C while stirring at 600 rpm under nitrogen flow, then the nitrogen flow was stopped, and oxygen was introduced at 60 mL / min to start the reaction.

[0083] After 24 hours of reaction, the oxygen bubbling was stopped and nitrogen was circulated. The dissolved oxygen concentration was maintained at 0 ppm for 1 hour, and then the mixture was filtered using a pressure filter at 80°C with nitrogen at 4 kgf / cm. 2The reaction liquid was filtered under pressure by injecting the pressure into the reaction vessel, and the reaction liquid and the catalyst were separated.

[0084] During the reaction, the reaction solution was sampled every hour, and the carboxylic acid compound production rate was determined by the method described below. The carboxylic acid compound production rates are summarized in Tables 1 to 4, respectively. (Calculation of Carboxylic Acid Compound Production Rate) A mixed solution of 60 mL of acetone and 10 mL of ion-exchanged water was added to 0.3 g of the sampled reaction solution and stirred to prepare a measurement sample. The measurement sample was titrated with a 0.05 mol / L ethanolic potassium hydroxide aqueous solution to measure the neutralization point. The actual acid value of the reaction solution was calculated from the determined neutralization point, and the carboxylic acid compound production rate was calculated using the following formula. Carboxylic acid compound production rate (%) = (actual acid value / theoretical acid value) x 100 Here, the theoretical acid value and the actually measured acid value were as follows. (1) Calculation of theoretical acid value: The OHV (hydroxyl value) of the organic compound (AE1) was calculated to be 162 mg KOH / g. )but Based on the molecular weight of the carboxylic acid compound obtained by oxidation, the acid value (theoretical acid value) when 100% of the carboxylic acid compound is produced in the reaction is 156 mgKOH / g. (2) Calculation of the measured acid value: The measured acid value was calculated from the neutralization point using the following formula. Measured acid value (mgKOH / g) = titration volume of potassium hydroxide solution (mL) × 56.11 (g / mol) × 0.05 (mol / L) / sampling volume (g) / 0.7692 (mass ratio of raw materials in the reaction solution)

[0085] <Examples 2 and 3> The reactions of Examples 2 and 3 were carried out in the same manner as in Example 1, except that the amount of bismuth oxide charged as the Bi ion source was changed as shown in Table 1. Table 1 shows the carboxylic acid compound production rate after 24 hours of reaction. Example 4 Example 4 was carried out in the same manner as Example 1, except that the Bi ion source was changed to 0.23 parts by mass of bismuth nitrate pentahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as shown in Table 1. ofThe reaction was carried out. Table 1 shows the carboxylic acid compound production rate after 24 hours of reaction. <Example 5> The reaction of Example 5 was carried out in the same manner as in Example 1, except that the type of organic compound was changed to K2098 (Kalcol 2098 (lauryl alcohol), manufactured by Kao Corporation) as shown in Table 2. The OHV of K2098 is 301 mg KOH / g, and the theoretical acid value of its oxidation product (carboxylic acid compound) is 280 mg KOH / g. Table 2 summarizes the carboxylic acid compound production rate after 7 hours of reaction. Example 6 The reaction of Example 6 was carried out in the same manner as in Example 1, except that the type of organic compound was changed to AE2 (a polyoxyalkylene alkyl ether in which an average of 9 moles of ethylene oxide was added to 1 mole of 1-octanol) as shown in Table 2, and the reaction time was changed to 7 hours. The OHV of AE2 was 107 mg KOH / g, and the theoretical acid value of its oxidation product (carboxylic acid compound) was 104 mg KOH / g. Table 2 summarizes the carboxylic acid compound production rate after 7 hours of reaction. <Comparative Example 1> As shown in Table 1, the reaction of Comparative Example 1 was carried out in the same manner as in Example 1, except that no Bi ion source was charged. Table 1 shows the carboxylic acid compound production rate after 24 hours of reaction. <Comparative Example 2> The reaction of Comparative Example 2 was carried out in the same manner as in Example 1, except that a pH meter (manufactured by Nisshin Rika Co., Ltd.) was attached to the reaction vessel, and a 48% aqueous solution of sodium hydroxide (manufactured by Kanto Chemical Co., Inc.) was added as an alkaline agent to maintain a constant pH of 7.0 during the reaction, while the reaction time was set to 9 hours. The carboxylic acid compound production rate was calculated by the following method, and the carboxylic acid compound production rate after 3 hours of reaction is summarized in Table 3. (Calculation of carboxylic acid compound generation rate when alkaline agent is added) 0.5 g of 6 M hydrochloric acid (Fujifilm Wako Pure Chemical Industries, Ltd.) was added to 1 g of the sampled reaction solution, mixed thoroughly, and then filtered with a syringe. After leaving it to stand, the oil and water were separated, and a methylation reagent (reagent name "TMSI-H", GL Science s1 mL of a soluble amine (manufactured by Co., Ltd.) was added, and the mixture was reacted at 70°C for 10 minutes, followed by syringe filtration and GC (gas chromatography) analysis. (GC measurement conditions) GC equipment: Agilent Technologies 6850 (Model number: Agilent 19091A-102E, manufactured by Agilent Technologies) Column: Ultra1 Methyl Siloxane (25.0 m x 200 μm x 0.33 μm) ·Injection temperature 300℃ Detector temperature 300℃ Temperature Program Hold at 100°C for 5 minutes, then raise the temperature to 300°C at a rate of 5°C / min (45 minutes in total), then hold at 300°C for another 40 minutes (90 minutes in total program) Injection volume 1.0μL Split ratio 25.0:1 Total flow 28.2mL / min. (Gas: He) <Comparative Example 3> The reaction was carried out in the same manner as in Comparative Example 2, except that the reaction time was set to 9 hours while adding a 48% aqueous sodium hydroxide solution (manufactured by Kanto Chemical Co., Inc.) as an alkaline agent so that the pH during the reaction was constant at 12.0. The carboxylic acid compound production rate was calculated by the method described in Comparative Example 2, and the carboxylic acid compound production rate after 3 hours of reaction is summarized in Table 3. <Reference example 1> The reaction of Reference Example 1 was carried out in the same manner as in Example 1, except that the catalyst separated and recovered from the reaction solution after completion of the reaction in Example 1 was charged instead of the Pt and Bi ion sources supported on a carrier, and the reaction time was 17 hours. The total amount of catalyst recovered in Example 1 was 17.80 g. The breakdown of the composition contained in the recovered catalyst was calculated from the charged amounts in Example 1 to be 10 g of 5% Pt / C and bismuth oxide in total, 1.56 g of water content, and 6.24 g of organic compounds (unreacted AE1 and carboxylic acid compounds). Table 4 summarizes the carboxylic acid compound production rate after 17 hours of reaction.

[0086] [Table 1]

[0087] [Table 2]

[0088] [Table 3]

[0089] [Table 4]

[0090] As can be seen from Tables 1 to 4, the Pt / Bi composite catalyst obtained by mixing Pt and Bi ion sources supported on a carrier in the presence of an organic compound having one primary hydroxyl group and reacting under conditions where the minimum pH during the reaction was less than 7 showed a high production rate of carboxylic acid compounds at all reaction times, and was able to efficiently obtain oxides of the target organic compounds. Furthermore, in Reference Example 1, in which the catalyst of Example 1 was separated and recovered and reused in the oxidation reaction of an organic compound, a high production rate of carboxylic acid compounds was also observed. On the other hand, with the Pt / Bi composite catalyst of Comparative Example 1, to which no Bi ion source was added, the amount of carboxylic acid compounds was about 74% after 24 hours, and the oxides of the target organic compounds could not be efficiently obtained. In addition, the Pt / Bi composite catalysts of Comparative Examples 2 and 3, in which an alkaline agent was added during the reaction and the minimum pH during the reaction was set to 7 or higher, had carboxylic acid compound production rates of 16.7% and 5.4%, respectively, after three hours of reaction, which were lower than the 37.9% production rate of carboxylic acid compounds after three hours of reaction in Example 1, resulting in poor reaction efficiency in the oxidation reaction of organic compounds. The production rate of carboxylic acid compounds after 17 hours of reaction in Reference Example 1 was 91.3%, which was higher than the production rate of 81.6% after 17 hours of reaction in Example 1. This is thought to be because the catalyst used in Reference Example 1 was a catalyst separated and recovered from the catalyst in Example 1, and therefore a highly active Pt-Bi / C catalyst was used that was presumed to have already been produced in the system. Therefore, there was no time for catalyst production in the system, and the oxidation reaction of the organic compounds began immediately after the start of the reaction in Reference Example 1. [Industrial Applicability]

[0091] The oxide production method of the present invention can efficiently produce an oxide of an organic compound in the presence of Pt and Bi ion sources supported on a carrier, and can also produce a Pt / Bi composite catalyst. Therefore, no additional facilities or processes for catalyst production are required, and the oxide of an organic compound can be efficiently produced. The obtained oxide of an organic compound can be used in a wide range of fields, such as detergents, fabric softeners, wetting agents, and dyeing aids. Furthermore, the method for producing a Pt / Bi composite catalyst of the present invention can produce a catalyst that exhibits high activity in the dehydrogenation reaction of organic compounds even in the presence of organic compounds that are raw materials for the oxides. Dehydrogenation oxidation Therefore, an oxide of an organic compound can be efficiently produced without requiring any additional facilities or processes for producing the catalyst, and the resulting Pt / Bi composite catalyst can be suitably used in a reaction for producing an oxide of the organic compound by dehydrogenating the organic compound.

Claims

1. In the presence of Pt supported on a support, a Bi ion source, and water, A method for producing an oxide, comprising: subjecting an organic compound having one primary hydroxyl group to a dehydrogenative oxidation reaction under conditions in which the minimum pH value during the reaction is less than 7, to obtain an oxide of the organic compound, adding a Bi ion source at the start of or during the dehydrogenation oxidation reaction; Method for producing oxides.

2. The method for producing the oxide according to claim 1 , which is accompanied by the preparation of a Pt / Bi composite catalyst.

3. The method for producing an oxide according to claim 1 or 2, wherein the Bi ion source is water-insoluble.

4. 4. The method for producing an oxide according to claim 1, wherein the Bi ion source is at least one selected from the group consisting of bismuth nitrate pentahydrate, bismuth oxide, basic bismuth carbonate, and bismuth hydroxide.

5. The method for producing an oxide according to any one of claims 1 to 4, wherein the organic compound is an aliphatic alcohol or a polyoxyalkylene alkyl ether.

6. The method for producing an oxide according to any one of claims 1 to 5, wherein the oxide of the organic compound is a carboxylic acid compound or a salt of a carboxylic acid compound.

7. The method for producing an oxide according to any one of claims 1 to 6, wherein the support is activated carbon.

8. A method for producing an oxide, comprising: subjecting an organic compound having one primary hydroxyl group to a dehydrogenative oxidation reaction in the presence of a Pt / Bi composite catalyst, a Bi ion source, and water under conditions where the minimum pH during the reaction is less than 7, to obtain an oxide of the organic compound, adding a Bi ion source at the start of or during the dehydrogenation oxidation reaction; Method for producing oxides.

9. The method for producing an oxide according to claim 8, which is accompanied by regeneration of the Pt / Bi composite catalyst.

10. In the presence of an organic compound having one primary hydroxyl group and water, Mixing Pt and Bi ion sources supported on a carrier; A method for producing a Pt / Bi composite catalyst, comprising reacting under conditions in which the minimum pH during the reaction is less than 7, Adding a Bi ion source at the start of or during the reaction; Method for producing Pt / Bi composite catalyst.

11. The method for producing a Pt / Bi composite catalyst according to claim 10, wherein the dehydrogenation reaction of the organic compound is accompanied.

12. 12. The method for producing a Pt / Bi composite catalyst according to claim 10, wherein the Bi ion source is water-insoluble.

13. 13. The method for producing a Pt / Bi composite catalyst according to claim 10, wherein the Bi ion source is at least one selected from the group consisting of bismuth nitrate pentahydrate, bismuth oxide, basic bismuth carbonate, and bismuth hydroxide.

14. The method for producing a Pt / Bi composite catalyst according to any one of claims 10 to 13, wherein the support is activated carbon.

15. In the presence of an organic compound having one primary hydroxyl group and water, Mixing a Pt / Bi composite catalyst and a Bi ion source; A method for producing a Pt / Bi composite catalyst, comprising reacting under conditions in which the minimum pH during the reaction is less than 7, Adding a Bi ion source at the start of or during the reaction to regenerate the Pt / Bi composite catalyst; Method for producing Pt / Bi composite catalyst.

16. A method for producing an oxide, comprising: subjecting an organic compound to a dehydrogenative oxidation reaction in the presence of the Pt / Bi composite catalyst obtained by the method for producing a Pt / Bi composite catalyst according to any one of claims 10 to 15, to obtain an oxide of the organic compound.

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