Method for producing aliphatic aldehydes

Abstract

This invention provides a method for efficiently producing aliphatic aldehydes by oxidizing aliphatic primary alcohols having four or more carbon atoms. [Solution] A method for producing an aliphatic aldehyde, comprising the step of oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a ruthenium-supported catalyst, The ruthenium-supported catalyst comprises ruthenium supported on a carrier, The aforementioned support is a porous oxide, The surface area per unit mass of ruthenium is 60 m². 2 / g or more The mesopore volume of the ruthenium-supported catalyst is 0.15 mL / g or more. A method for producing aliphatic aldehydes.

Description

Technical Field

[0001] The present invention relates to a method for producing aliphatic aldehydes.

Background Art

[0002] Conventionally, as a method for producing carbonyl compounds, a method of oxidizing alcohols in the presence of a metal catalyst to obtain carbonyl compounds is known.

[0003] For example, Patent Document 1 discloses a paper catalyst structure containing metal oxide fibers, alumina, and ruthenium. In this paper catalyst structure, a coating layer containing alumina having a γ structure is formed on the surface of the metal oxide fibers, and ruthenium is held by the coating layer containing alumina having a γ structure. This paper catalyst structure is reported to have high catalytic activity and to be suitable as an oxidation catalyst for alcohols.

[0004] Patent Document 2 discloses a method for producing a carbonyl compound, which comprises oxidizing a specific alcohol in the presence of a catalyst in which at least one metal selected from ruthenium and platinum is supported on an activated carbon carrier and oxygen to produce a carbonyl compound composed of an aldehyde compound or a ketone compound. According to this method, it is reported that carbonyl compounds can be produced from various alcohols in a higher yield.

[0005] Patent Document 3 discloses a method for producing ruthenium-supported alumina, which comprises suspending alumina in a solution containing trivalent ruthenium and then adding a base. According to the method for oxidizing an alcohol using this ruthenium-supported alumina, it is reported that an alcohol can be oxidized at a high conversion rate to produce ketones, aldehydes, carboxylic acids, etc. with good productivity.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] However, the methods described in Patent Documents 1 and 2 are suitable for oxidizing aromatic alcohols and aliphatic secondary alcohols from the viewpoint of reactivity, but are not necessarily suitable for oxidizing aliphatic primary alcohols. Further, in the method described in Patent Document 3, the reaction efficiency of the catalyst is not sufficient.

[0008] Therefore, an object of the present invention is to provide a method for efficiently producing an aliphatic aldehyde by oxidizing an aliphatic primary alcohol having 4 or more carbon atoms. [Means for Solving the Problems]

[0009] The present invention is a method for producing an aliphatic aldehyde, comprising a step of oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a ruthenium-supported catalyst, wherein the ruthenium-supported catalyst contains ruthenium supported on a carrier, the carrier is a porous oxide, the surface area per unit mass of ruthenium is 60 m 2 / g or more, the mesopore volume of the ruthenium-supported catalyst is 0.15 mL / g or more, which is a method for producing an aliphatic aldehyde. [Effects of the Invention]

[0010] The method of the present invention has an advantage that an aliphatic aldehyde can be efficiently produced by oxidizing an aliphatic primary alcohol having 4 or more carbon atoms (hereinafter, also simply referred to as an aliphatic primary alcohol). [Modes for Carrying Out the Invention]

[0011] The present inventors have discovered that by using a ruthenium-supported catalyst containing ruthenium supported on a carrier, wherein the ruthenium has a specific metallic specific surface area and the catalyst has a specific mesopore volume, it is possible to efficiently produce aliphatic aldehydes by oxidizing aliphatic primary alcohols having 4 or more carbon atoms, thus completing the present invention.

[0012] [Method for producing aliphatic aldehydes] The present invention is a method for producing aliphatic aldehydes, comprising the step of oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a ruthenium-supported catalyst, The ruthenium-supported catalyst comprises ruthenium supported on a carrier, The aforementioned support is a porous oxide, The surface area per unit mass of ruthenium is 60 m². 2 / g or more The mesopore volume of the ruthenium-supported catalyst is 0.15 mL / g or more. This is a method for producing aliphatic aldehydes.

[0013] The present invention is characterized by the use of a specific ruthenium-supported catalyst in its manufacturing method. This method allows for the efficient production of aliphatic aldehydes by oxidizing aliphatic primary alcohols having four or more carbon atoms. This is presumed to be because the hydroxyl group, which is the active site of aliphatic primary alcohols having four or more carbon atoms, is suitable for the catalyst structure described above.

[0014] Furthermore, according to the manufacturing method of the present invention, aliphatic aldehydes can be produced in a short time by oxidizing aliphatic primary alcohols having 4 or more carbon atoms. Therefore, it is believed that the side reaction of further oxidation of aliphatic aldehydes to carboxylic acids can be suppressed.

[0015] <Aliphatic primary alcohols with 4 or more carbon atoms> In the present invention, the aliphatic primary alcohol having 4 or more carbon atoms may be linear or branched, and may be saturated or unsaturated. From the viewpoint of high reactivity in a short time, the aliphatic primary alcohol is preferably a linear saturated primary alcohol, and more preferably a linear saturated primary alcohol having 8 to 14 carbon atoms.

[0016] From the viewpoint of reactivity, the number of carbon atoms in the aliphatic primary alcohol is preferably 4 or more, more preferably 6 or more, even more preferably 7 or more, and even more preferably 8 or more. Similarly, it is preferably 30 or less, more preferably 22 or less, even more preferably 14 or less, and even more preferably 12 or less. From the viewpoint of reactivity, the number of carbon atoms in the aliphatic primary alcohol is preferably 4 to 30, more preferably 6 to 22, even more preferably 6 to 14, even more preferably 8 to 14, and even more preferably 8 to 12.

[0017] Specifically, the aliphatic primary alcohols include: C4 alcohols such as n-butyl alcohol and iso-butyl alcohol; C6 alcohols such as hexyl alcohol and isohexyl alcohol; C8 alcohols such as n-octyl alcohol (octanol), isooctyl alcohol, and 2-ethylhexyl alcohol; C9 alcohols such as n-nonyl alcohol, isononyl alcohol, and 3,5,5-trimethylhexyl alcohol; C10 alcohols such as n-decyl alcohol, 3,7-dimethyloctyl alcohol, and 2-propylheptyl alcohol; and n-undecyl alcohol. Examples include C11 alcohols such as kohl and 2-methyldecanol; C12 alcohols such as n-dodecyl alcohol (lauryl alcohol), 2-methylundecanol, and 2-butyloctanol; C14 alcohols such as myristyl alcohol (1-tetradecanol); C18 alcohols such as hexadecyl alcohols, oleyl alcohol, and stearyl alcohol; and behenyl alcohol, eicosyl alcohols, geraniol, nerol, citronellol, cyclopentylmethanol, cyclopentenylmethanol, cyclohexylmethanol, and cyclohexenylmethanol. The aliphatic primary alcohol is preferably aliphatic linear saturated primary alcohol having 4 to 30 carbon atoms, more preferably 6 to 22 carbon atoms, even more preferably 6 to 14 carbon atoms, even more preferably 8 to 14 carbon atoms, and even more preferably 8 to 12 carbon atoms.

[0018] <Ruthenium-supported catalyst> In the manufacturing method of the present invention, the ruthenium-supported catalyst has ruthenium supported on a carrier.

[0019] The ruthenium-supported catalyst has a surface area of ​​60 m² per unit mass of ruthenium. 2is 60 m² / g or more. A large surface area per unit mass of ruthenium means that the particle size of ruthenium is small and ruthenium is widely dispersed on the carrier, that is, dispersed on a carrier with a large pore volume. The surface area per unit mass of ruthenium can be measured by the pulse method, particularly the CO pulse method.

[0020] The surface area per unit mass of ruthenium is 60 m 2 / g or more, preferably 65 m 2 / g or more, preferably 70 m 2 / g or more, more preferably 100 m 2 / g or more, even more preferably 130 m 2 / g or less, and from the same perspective, 250 m 2 / g or less, preferably 200 m 2 / g or less, more preferably 190 m 2 / g or less, still more preferably 180 m 2 / g or less, still more preferably 170 m 2 / g or less, still more preferably 160 m 2 / g or less. The ruthenium surface area per unit mass of ruthenium is 60 m 2 / g or more and 250 m 2 / g or less, preferably 65 m 2 / g or more and 250 m 2 / g or less, more preferably 65 m 2 / g or more and 200 m 2 / g or less, more preferably 70 m 2 / g or more and 200 m 2 / g or less, still more preferably 70 m 2 / g or more and 190 m 2 / g or less, even more preferably 70 m 2 / g or more and 180 m 2 / g or less, more preferably 70 m 2 / g or more and 170 m 2 / g or less, still more preferably 100 m 2 / g or more and 170 m 2 / g or less, even more preferably 130 m 2 / g or more and 160 m 2 / g or less.

[0021] From the viewpoint of reactivity, the particle size of ruthenium is preferably 1 nm or more, more preferably 2 nm or more, and even more preferably 2.5 nm or more. Similarly, from the same viewpoint, it is preferably 20 nm or less, more preferably 10 nm or less, and even more preferably 5 nm or less. This particle size was calculated using the metal surface area and the ratio of the volume when the particle is assumed to be perfectly spherical to the surface area per unit mass of ruthenium. From the viewpoint of reactivity, the particle size of ruthenium is preferably 1 nm or more and 20 nm or less, more preferably 2 nm or more and 10 nm or less, and even more preferably 2.5 nm or more and 5 nm or less.

[0022] The surface area per unit mass of ruthenium can be adjusted during catalyst preparation by increasing the amount of ruthenium compound relative to the raw material carrier, or by using a carrier with a large surface area, i.e., a highly porous carrier. In this case, as will be described later, in order to increase catalytic activity and the surface area per unit mass of ruthenium, it is preferable to reduce the macropores of the carrier and increase the mesopore volume.

[0023] The support is a porous oxide. The porous oxide is preferably one or more selected from the group consisting of alumina, titania, zirconia, silica, silica-alumina, magnesia, zeolite, and activated carbon. From the viewpoint of high activity and high selectivity, the support is preferably alumina, activated carbon, titania, silica-alumina, or zeolite, with alumina and activated carbon being more preferred. In the present invention, the porous oxide may be used alone or in combination of two or more types.

[0024] The mesopore volume of the ruthenium-supported catalyst is 0.15 mL / g or more. The mesopore volume can be measured by mercury porosimetry according to ASTM D4284-83. Specifically, the measurement is performed by filling a measurement cell containing the sample with mercury and pressurizing the inside of the cell. Then, the amount of mercury that enters is detected by a capacitance detector and the pore volume is measured. Alternatively, the mesopore volume can be calculated by determining the pore distribution by modeling the pores as cylindrical. A catalyst having the aforementioned mesopore volume of 0.15 mL / g or more is considered to be a catalyst with a pore size suitable for the reaction field of the oxidation reaction of the aliphatic primary alcohol.

[0025] The mesopore volume of the ruthenium-supported catalyst is preferably 0.15 mL / g or more, preferably 0.2 mL / g or more, more preferably 0.25 mL / g or more, from the viewpoint of increasing the reactivity of aliphatic primary alcohols having 4 or more carbon atoms and suppressing further oxidation of aldehydes to carboxylic acids, and from the viewpoint of catalyst preparation, preferably 0.5 mL / g or less, more preferably 0.45 mL / g or less, and even more preferably 0.4 mL / g or less. The mesopore volume of the catalyst is preferably 0.15 mL / g or more and 0.5 mL / g or less, more preferably 0.2 mL / g or more and 0.5 mL / g or less, even more preferably 0.25 mL / g or more and 0.5 mL / g or less, even more preferably 0.25 mL / g or more and 0.45 mL / g or less, and even more preferably 0.25 mL / g or more and 0.4 mL / g or less, from the viewpoint of increasing the reactivity of aliphatic primary alcohols having 4 or more carbon atoms and suppressing further oxidation of aldehydes to carboxylic acids, and from the viewpoint of catalyst preparation.

[0026] The ruthenium metal content in the ruthenium-supported catalyst is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, relative to the entire catalyst, from the viewpoint of reactivity. Similarly, it is preferably 50% by mass or less, more preferably 30% by mass or less, even more preferably 10% by mass or less, and even more preferably less than 10% by mass. The ruthenium metal content in the ruthenium-supported catalyst is preferably 1% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 30% by mass or less, even more preferably 1% by mass or more and 10% by mass or less, even more preferably 1% by mass or more and less than 10% by mass, relative to the entire catalyst, from the viewpoint of reactivity.

[0027] <Method for producing ruthenium-supported catalysts> The ruthenium-supported catalyst used in this invention has ruthenium supported on a carrier, the carrier being a porous oxide, and the surface area per unit mass of ruthenium being 60 m². 2 A commercially available ruthenium-supported catalyst may be used, having a ruthenium content of 0.15 mL / g or more and a mesopore volume of 0.15 mL / g or more. Alternatively, such a ruthenium-supported catalyst may be manufactured in accordance with known technology or common technical knowledge. Examples of such manufacturing methods include impregnation methods in which ruthenium is impregnated into a support, and liquid-phase reduction methods in which a reducing agent is added.

[0028] An example of a method for producing the ruthenium-supported catalyst used in the present invention is described below. First, the porous oxide is added to a medium such as deionized water and suspended. Then, a solution of the ruthenium compound dissolved in an aqueous solvent such as deionized water is added to this suspension, and the mixture is heated while stirring as needed to adjust the temperature to about 20-95°C, preferably 40-80°C, to obtain a suspension containing the ruthenium compound. Examples of the ruthenium compound include ruthenium chloride, nitrate, formate, and ammonium salt.

[0029] Next, an alkali is added to the suspension containing the ruthenium compound to adjust the pH to 4-12, preferably 6-11, and hydrolysis is carried out, followed by aging to support the ruthenium component on a porous oxide. There are no particular restrictions on the type of alkali, but ammonia water, alkali metal carbonates such as sodium and potassium, hydroxides, etc., can be used. The time for adjusting the pH and aging is not particularly limited as long as sufficient time is provided for the ruthenium compound to hydrolyze.

[0030] Next, a reducing agent such as formaldehyde, hydrazine, or sodium borohydride is added to the reaction solution, and the mixture is heated as needed. After reduction treatment at a temperature of approximately 20-95°C, preferably 60-95°C, the solid-liquid separation is performed by filtration or the like. The obtained solid is thoroughly washed with water and then dried at a temperature of preferably 140°C or lower under atmospheric pressure or reduced pressure. The reducing agent may be used alone or in combination of two or more types. In order to effectively reduce the supported ruthenium component, the reducing agent is usually used in a ratio of approximately 1-50 molars, preferably 15-40 molars, relative to the ruthenium. The duration of the reduction treatment described above is not particularly limited, as long as sufficient time is available for the reduction reaction to proceed to the desired extent. The reduction procedure described above is not necessarily required. After supporting the ruthenium component by hydrolysis, solid-liquid separation may be performed, and the resulting solid material may be thoroughly washed with water and dried.

[0031] When ruthenium components are supported on porous oxides by hydrolysis as described above, it is not necessarily required to perform operations such as high-temperature calcination or high-temperature reduction under an inert gas atmosphere, which are usually carried out in impregnation methods, and the preparation of the catalyst is simple. The ruthenium-supported catalyst obtained in this manner contains ruthenium as metal in a proportion of preferably 1 to 50% by mass, more preferably 3 to 30% by mass, based on the total amount of catalyst including porous oxides, from the viewpoint of sufficient catalytic activity, selectivity, and economic efficiency. The ruthenium content in the catalyst can be measured by ICP emission spectrometry after the catalyst has been melted with ammonium bisulfate.

[0032] <Method for producing aliphatic aldehydes> The present invention's manufacturing method includes a step of oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a ruthenium-supported catalyst. In this process, the molar ratio of ruthenium (mmol) to aliphatic primary alcohol (mmol) having 4 or more carbon atoms, i.e., the molar ratio of ruthenium (mmol) to aliphatic primary alcohol (mmol) having 4 or more carbon atoms, varies depending on the reaction temperature, etc., but is generally preferably 0.001 or higher, more preferably 0.005 or higher, and even more preferably 0.01 or higher from the viewpoint of reactivity, and preferably 0.5 or lower, more preferably 0.2 or lower, more preferably 0.1 or lower, even more preferably 0.05 or lower, and even more preferably 0.045 or lower from the viewpoint of efficiency. The molar ratio of ruthenium (mmol) to aliphatic primary alcohol (mmol) having 4 or more carbon atoms is preferably 0.001 to 0.5, preferably 0.001 to 0.2, more preferably 0.001 to 0.1, even more preferably 0.001 to 0.05, even more preferably 0.001 to 0.045, even more preferably 0.005 to 0.1, even more preferably 0.005 to 0.05, even more preferably 0.005 to 0.045, even more preferably 0.01 to 0.05, and even more preferably 0.01 to 0.045.

[0033] The molecular oxygen (referring to elemental molecular oxygen (oxygen gas); the same applies hereinafter) functions as an oxidizing agent in this step. This molecular oxygen is present in the reaction system of the present invention and only needs to be in contact with an aliphatic primary alcohol having 4 or more carbon atoms. Specifically, this step can be carried out in an atmospheric environment. Furthermore, it is preferable to carry out this step in an oxygen atmosphere because the oxidation reaction of aliphatic primary alcohols having 4 or more carbon atoms can be carried out more efficiently. An oxygen atmosphere may include gases other than oxygen, such as air, and may be 100% oxygen, or it may include oxygen and an inert gas such as nitrogen, helium, or argon. In an oxygen atmosphere, the oxygen gas concentration is preferably 5% by volume or more, and more preferably 10% by volume or more. In an oxygen atmosphere, it is preferable to have a high concentration of oxygen, as a high concentration of oxygen can increase the reaction efficiency.

[0034] This step may be carried out in the presence of a solvent. The solvent is preferably one that can dissolve the aliphatic primary alcohol, such as water and organic solvents. Examples of such solvents include aromatic solvents such as toluene, liquid paraffin, and hydrocarbon solvents such as squalene. Among these, from the viewpoint of reaction efficiency, aromatic organic solvents having 6 to 40 carbon atoms are preferred. The solvent can be used alone or in combination of two or more.

[0035] In this process, the ratio of solvent (mL) to aliphatic primary alcohol (mmol) having 4 or more carbon atoms, i.e., solvent (mL) / aliphatic primary alcohol (mmol) having 4 or more carbon atoms, is preferably 0.01 or more, more preferably 0.05 or more, and even more preferably 0.1 or more, from the viewpoint of reactivity, and similarly, preferably 6 or less, more preferably 4 or less, and even more preferably 2 or less. The ratio of solvent to aliphatic primary alcohol having 4 or more carbon atoms is preferably 0.01 or more and 6 or less, more preferably 0.05 or more and 4 or less, and even more preferably 0.1 or more and 2 or less, from the viewpoint of reactivity. The initial aldehyde activity value (per unit time and unit catalytic amount) is preferably 2 mmol / g / hr or more, more preferably 3 mmol / g / hr or more, and even more preferably 4 mmol / g / hr or more, with an upper limit of 10 mmol / g / hr or less. Here, mol is the number of moles of aldehyde after the reaction, g is the amount of ruthenium-supported catalyst, and hr is the reaction time, which are calculated according to the formula in the example.

[0036] The reaction temperature in this process is not particularly limited. When heating is used, the reaction temperature is preferably below the boiling point of the solvent used. From the viewpoint of reactivity, the reaction temperature is preferably 60°C or higher, more preferably 70°C or higher, and even more preferably 80°C or higher. From the viewpoint of productivity, it is preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 170°C or lower. From the viewpoint of reactivity and productivity, the reaction temperature is preferably 60°C to 200°C, more preferably 70°C to 180°C, and even more preferably 80°C to 170°C.

[0037] The pressure used in this process is not limited, but it is preferable to perform it at atmospheric pressure or under reduced pressure.

[0038] The manufacturing method of the present invention is suitable not only for batch production but also for continuous flow production, as it can produce aldehydes in a short time and with high yield. The present invention includes the following embodiments. [1] A method for producing an aliphatic aldehyde, comprising the step of oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a ruthenium-supported catalyst, The ruthenium-supported catalyst comprises ruthenium supported on a carrier, The aforementioned support is a porous oxide, The surface area per unit mass of ruthenium is 60 m². 2 / g or more The mesopore volume of the ruthenium-supported catalyst is 0.15 mL / g or more. A method for producing aliphatic aldehydes.

[0039] [2] The surface area per unit mass of ruthenium is 60 m 2 / g or more 250m 2 The manufacturing method described in [1], which is less than or equal to / g.

[0040] [3] The surface area per unit mass of ruthenium is 65 m 2 / g or more 250m 2 The manufacturing method described in [1] or [2], wherein the result is less than or equal to / g.

[0041] [4] The surface area per unit mass of ruthenium is preferably 70 m 2 / g or more 200m 2 A manufacturing method described in any of [1] to [3], wherein the amount is less than or equal to / g.

[0042] [5] The surface area per unit mass of ruthenium is 70 m 2 / g or more 190m 2 A manufacturing method described in any of [1] to [4], which is less than or equal to / g. [6] The surface area per unit mass of ruthenium is 70 m 2 / g or more 180m 2 A manufacturing method described in any of [1] to [5], which is less than or equal to / g. [7] The surface area per unit mass of ruthenium is 70 m 2 / g or more 170m 2 A manufacturing method described in any of [1] to [6], which is less than or equal to / g. [8] The surface area per unit mass of ruthenium is 100 m 2 / g or more 170m 2 A manufacturing method described in any of [1] to [7], which is less than or equal to / g. [9] The surface area per unit mass of ruthenium is 130 m 2 / g or more 160m 2 A manufacturing method described in any of [1] to [8], which is less than or equal to / g.

[10] The manufacturing method according to any one of [1] to [9], wherein the particle size of the ruthenium is 1 nm or more and 20 nm or less.

[0043]

[11] The manufacturing method according to any one of [1] to

[10] , wherein the particle size of the ruthenium is 2 nm or more and 10 nm or less.

[0044]

[12] The manufacturing method according to any one of [1] to

[11] , wherein the particle size of the ruthenium is 2.5 nm or more and 5 nm or less.

[0045]

[13] The manufacturing method according to any one of [1] to

[12] , wherein the mesopore volume of the ruthenium-supported catalyst is 0.15 mL / g or more and 0.5 mL / g or less.

[0046]

[14] The manufacturing method according to any one of [1] to

[13] , wherein the mesopore volume of the ruthenium-supported catalyst is 0.2 mL / g or more and 0.5 mL / g or less.

[0047]

[15] The manufacturing method according to any one of [1] to

[14] , wherein the mesopore volume of the ruthenium-supported catalyst is 0.25 mL / g or more and 0.5 mL / g or less.

[0048]

[16] The manufacturing method according to any one of [1] to

[15] , wherein the mesopore volume of the ruthenium-supported catalyst is 0.25 mL / g or more and 0.45 mL / g or less.

[0049]

[17] The manufacturing method according to any one of [1] to

[16] , wherein the mesopore volume of the ruthenium-supported catalyst is 0.25 mL / g or more and 0.4 mL / g or less.

[0050]

[18] The manufacturing method according to any one of [1] to

[17] , wherein the ruthenium metal content in the ruthenium-supported catalyst is preferably 1% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 30% by mass or less, even more preferably 1% by mass or more and 10% by mass or less, even more preferably 1% by mass or more and less than 10% by mass, even more preferably 3% by mass or more and 10% by mass or less, even more preferably 5% by mass or more and less than 10% by mass.

[0051]

[19] The method for producing the aliphatic primary alcohol according to any one of [1] to

[18] , wherein the number of carbon atoms in the aliphatic primary alcohol is preferably 4 to 30, more preferably 6 to 22, even more preferably 6 to 14, even more preferably 8 to 14, and even more preferably 8 to 12.

[0052]

[20] The method of production according to any one of [1] to

[19] , wherein the aliphatic primary alcohol is an aliphatic linear saturated primary alcohol, preferably an aliphatic linear saturated primary alcohol having 8 to 14 carbon atoms.

[0053]

[21] The manufacturing method according to any one of [1] to

[20] , wherein the porous oxide is one or more selected from the group consisting of alumina, titania, zirconia, silica, silicaalumina, magnesia, zeolite, and activated carbon.

[0054]

[22] The manufacturing method according to any one of [1] to

[21] , wherein the porous oxide is preferably alumina, activated carbon, titania, silica alumina, or zeolite, and more preferably alumina or activated carbon.

[0055]

[23] The manufacturing method according to [1] to

[22] , wherein the molar ratio of ruthenium (mmol) to aliphatic primary alcohol (mmol) having 4 or more carbon atoms [ruthenium (mmol) / aliphatic primary alcohol (mmol) having 4 or more carbon atoms] is preferably 0.001 or more and 0.2 or less, more preferably 0.001 or more and 0.1 or less, even more preferably 0.001 or more and 0.05 or less, even more preferably 0.001 or more and 0.045 or less, even more preferably 0.005 or more and 0.05 or less, even more preferably 0.005 or more and 0.045 or less, even more preferably 0.01 or more and 0.045 or less.

[0056]

[24] The manufacturing method according to any one of [1] to

[23] , wherein the temperature of the oxidation step is preferably 60°C to 200°C, more preferably 70°C to 180°C, and even more preferably 80°C to 170°C.

[25] A manufacturing method according to any one of [1] to

[24] , wherein the oxidation step is carried out in the presence of a solvent.

[26] The manufacturing method according to

[25] , wherein the molar ratio of ruthenium (mmol) to aliphatic primary alcohol (mmol) having 4 or more carbon atoms [ruthenium (mmol) / aliphatic primary alcohol (mmol) having 4 or more carbon atoms] is preferably 0.001 or more and 0.2 or less, more preferably 0.005 or more and 0.1 or less, and even more preferably 0.01 or more and 0.05 or less.

[27] The initial activity value of the aldehyde (per unit time and unit amount of catalyst) is preferably 2 mmol / g / hr or more, more preferably 3 mmol / g / hr or more, and even more preferably 4 mmol / g / hr or more, according to any one of [1] to

[26] .

[0057] The present invention will be described in more detail below with reference to examples. In the following examples, the measurement and evaluation of each physical property was performed by the following methods.

[0058] <Method for measuring the surface area per unit mass and particle size of ruthenium> The surface area per unit mass of ruthenium was measured using the CO pulse method with a BELCAT-B system manufactured by Nippon Bell. Pretreatment for the measurement involved reducing the active metal species (ruthenium) in the sample (catalyst) by passing helium gas through it at 200°C for 15 minutes, followed by passing hydrogen gas through it for 15 minutes. The measurement was performed using a 10% CO / He gas at 50°C under pulsed conditions. The surface area of ​​the active metal species was calculated based on the number of moles of CO adsorbed onto the active metal species before equilibrium was reached. The stoichiometric ratio of the active metal species to CO was set to 1.

[0059] Using the obtained surface area per unit mass of ruthenium, the particle size of the active metal species (ruthenium) was calculated using the following formula based on the ratio of the volume (assuming the sample particles are perfectly spherical) to the surface area per unit mass of ruthenium. The density when ruthenium is used as the active metal species is 12.410 g / cm³. 3 That is the case.

[0060]

number

[0061] In the formula, X is the density (g / cm³) of ruthenium (an active metal species). 3 ) and Y is the surface area per unit mass of ruthenium (m²). 2 It is / g).

[0062] <Method for measuring the mesopore volume of a catalyst> The mesopore volume of the catalyst was measured by mercury intrusion porosimetry in accordance with ASTM standard ASTM D4284-83 (Standard method for measuring the pore volume distribution of catalysts by mercury intrusion porosimetry). Specifically, the mercury intrusion method was performed using Micromeritrics AutoPore IV. The measurement pressure was 1.5 to 60,000 psia, and the equilibrium time was 5 seconds. The mesopore capacity of a catalyst is defined as the cumulative volume of mercury introduced at pressures between 30 MPa and 400 MPa, corresponding to the volume contained in pores with apparent diameters between 2 and 50 nm.

[0063] <Gas chromatography equipment and analytical conditions> GC system: Agilent Technologies, Inc. 7890B, flame ionization detector

[0064] A DB-1 column (capillary column, 100% dimethylpolysiloxane, inner diameter 0.25 mm, length 30 m, film thickness 0.25 μm, manufactured by Agilent Technologies, Inc.) was used. Carrier gas: Nitrogen, 1.5 mL / min Injection conditions: 280°C, split ratio 100 / 1 Injection volume: 1 μL Detection conditions: FID method, 280°C Column temperature conditions: Starting at 100°C, the temperature was held at 100°C for 2 minutes, then increased at a rate of 8°C / min to 180°C, and then increased at a rate of 10°C / min to 280°C. The temperature was then held at 280°C for 5 minutes.

[0065] [Examples, Comparative Examples] In the following examples and comparative examples, "%" refers to "mass%" unless otherwise specified. The following raw materials were used in the reaction. Octanol: Manufactured by Kao Corporation. Toluene: Manufactured by Fujifilm Wako Pure Chemical Corporation, Wako Special Grade. Tetradecane: Manufactured by Fujifilm Wako Pure Chemical Corporation, Wako Special Grade. Diethyl ether: Manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Wako Special Grade.

[0066] [Example 1] In a glass reaction tube with an inner diameter of 34 mm, a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, S type, surface area per unit mass of ruthenium 73.1 m²) is used as the catalyst. 2 The following were added: ruthenium (particle size 6.6 nm, mesopore volume 0.31 mL / g, dry mass 0.10 g), 1-octanol (0.26 g, 2.0 mmol, ruthenium / 1-octanol molar ratio 0.025), toluene (solvent, 4.0 mL, 3.47 g), and tetradecane (GC internal standard, 0.026 g). An oxygen-filled balloon was connected to the reaction tube to purge the reaction tube with oxygen, and the mixture in the reaction tube was stirred at 90°C for 2 hours. After that, the reaction tube was cooled to 30°C to terminate the reaction.

[0067] The reaction results were obtained by quantitatively analyzing each component of the reaction solution, collected 2 hours after the start of heating and stirring, using GC (gas chromatography) and the internal standard method. Using the amounts of each component obtained in the reactants, the initial aldehyde activity (2h), aldehyde yield (2h), and carboxylic acid production rate (2h) were calculated according to the following formula. Tetradecane was used as the internal standard, and diethyl ether was used as the solvent. The obtained initial aldehyde activity, aldehyde yield, and carboxylic acid production rate (by-product) are shown in Table 1 below.

[0068] Specifically, 0.2 mL of the reaction solution was sampled, and the catalyst was removed by filtering the solution through a membrane filter (polytetrafluoroethylene (PTFE), 0.2 μm). The resulting filtrate was taken into a screw tube containing 2 mL of diethyl ether, diluted, and then subjected to GC analysis.

[0069] <Method for calculating the initial activity of aldehydes> The initial aldehyde activity was calculated using the mass of octanal in the reaction solution, obtained by GC analysis of the reaction solution collected 2 hours after the start of heating and stirring, according to the following formula. A higher initial aldehyde activity value indicates better initial activity.

[0070]

number

[0071] <Method for measuring aldehyde yield> The aldehyde yield was calculated using the mass of octanal in the reaction solution, obtained by GC analysis of the reaction solution collected 2 hours after the start of heating and stirring, according to the following formula. A higher aldehyde yield value indicates a better yield.

[0072]

number

[0073] <Method for measuring carboxylic acid production rate> The carboxylic acid production rate was calculated using the mass of octanoic acid in the reaction solution, obtained by GC analysis of the reaction solution collected 2 hours after the start of heating and stirring, according to the following formula. A smaller carboxylic acid production rate indicates better suppression of carboxylic acid production.

[0074]

number

[0075] [Example 2] As a catalyst, a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, S type, surface area per unit mass of ruthenium 73.1 m²) is used. 2 Instead of ruthenium particle size 6.6 nm, mesopore volume 0.31 mL / g, dry mass 0.10 g), a 5% alumina-supported ruthenium catalyst (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., surface area per unit mass of ruthenium 142.1 m²) is used. 2 The procedure was carried out in the same manner as in Example 1, except that ruthenium particles (particle size 3.4 nm, mesopore volume 0.28 mL / g, dry mass 0.10 g) were used.

[0076] [Example 3] As a catalyst, a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, S type, surface area per unit mass of ruthenium 73.1 m²) is used. 2 Instead of ruthenium particle size 6.6 nm, mesopore volume 0.31 mL / g, dry mass 0.10 g), a 5% activated carbon-supported ruthenium catalyst (manufactured by N.E. Chemcat, type A, surface area per unit mass of ruthenium 145.7 m²) is used. 2 The procedure was carried out in the same manner as in Example 1, except that ruthenium (particle size 3.3 nm, mesopore volume 0.31 mL / g, dry mass 0.10 g) was used.

[0077] [Example 4] As a catalyst, a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, S type, surface area per unit mass of ruthenium 73.1 m²) is used. 2 Instead of a ruthenium catalyst (HYAc-5E, N-type, 154 m² / g, ruthenium particle size 6.6 nm, mesopore volume 0.31 mL / g, dry mass 0.10 g), a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, N-type, ruthenium surface area per unit mass 154 m²) is used. 2 The procedure was carried out in the same manner as in Example 1, except that ruthenium particles (particle size 3.1 nm, mesopore volume 0.30 mL / g, dry mass 0.10 g) were used.

[0078] [Example 5] As a catalyst, a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, S type, surface area per unit mass of ruthenium 73.1 m²) is used. 2 Instead of using a 5% activated carbon-supported ruthenium catalyst (Johnson Matthey, Type 600, surface area per unit mass of ruthenium 197.3 m²) (ruthenium particle size 6.6 nm, mesopore volume 0.31 mL / g, dry mass 0.10 g), use a 5% activated carbon-supported ruthenium catalyst (Johnson Matthey, Type 600, surface area per unit mass of ruthenium 197.3 m²). 2 The procedure was carried out in the same manner as in Example 1, except that ruthenium particles (particle size 2.5 nm, mesopore volume 0.24 mL / g, dry mass 0.10 g) were used.

[0079] [Comparative Example 1] As a catalyst, a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, S type, surface area per unit mass of ruthenium 73.1 m²) is used. 2 The procedure was carried out in the same manner as in Example 1, except that a 5% alumina-supported palladium catalyst (manufactured by Tokyo Chemical Industry Co., Ltd., dry mass 0.10 g) was used instead of ruthenium (particle size 6.6 nm, mesopore volume 0.31 mL / g, dry mass 0.10 g).

[0080] [Comparative Example 2] As a catalyst, a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, S type, surface area per unit mass of ruthenium 73.1 m²) is used. 2 The procedure was carried out in the same manner as in Example 1, except that a 5% activated carbon-supported palladium catalyst (Johnson Matthey, Type 39, dry mass 0.10 g) was used instead of ruthenium (particle size 6.6 nm, mesopore volume 0.31 mL / g, dry mass 0.10 g).

[0081] [Comparative Example 3] As a catalyst, a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, S type, surface area per unit mass of ruthenium 73.1 m²) is used. 2The procedure was carried out in the same manner as in Example 1, except that a 5% activated carbon-supported rhodium catalyst (Kawasaki Fine Chemicals, Type K, dry mass 0.10 g) was used instead of ruthenium (particle size 6.6 nm, mesopore volume 0.31 mL / g, dry mass 0.10 g).

[0082] [Comparative Example 4] As a catalyst, a 5% alumina-supported ruthenium catalyst (N.E. Chemcat, HYAc-5E, S type, surface area per unit mass of ruthenium 73.1 m²) is used. 2 Instead of ruthenium particle size 6.6 nm, mesopore volume 0.31 mL / g, dry mass 0.10 g), a 5% activated carbon-supported ruthenium catalyst (manufactured by Kawaken Fine Chemicals, type SD, surface area per unit mass of ruthenium 44.3 m²) is used. 2 The procedure was carried out in the same manner as in Example 1, except that ruthenium particles (particle size 10.9 nm, mesopore volume 0.17 mL / g, dry mass 0.10 g) were used.

[0083] Table 1 below shows the initial aldehyde activity, aldehyde yield, and carboxylic acid production rate obtained for Examples 1-5 and Comparative Examples 1-4.

[0084] [Table 1]

[0085] As shown in Table 1, it was confirmed that the method of the present invention can efficiently produce aliphatic aldehydes by oxidizing aliphatic primary alcohols having 4 or more carbon atoms in a short time. Furthermore, it was confirmed that the method of the present invention can produce aliphatic aldehydes by oxidizing aliphatic primary alcohols having 4 or more carbon atoms while suppressing the formation of carboxylic acids.

Claims

1. A method for producing an aliphatic aldehyde, comprising the step of oxidizing an aliphatic primary alcohol having 4 or more carbon atoms with molecular oxygen in the presence of a ruthenium-supported catalyst, The ruthenium-supported catalyst comprises ruthenium supported on a carrier, The aforementioned support is a porous oxide, The surface area per unit mass of ruthenium is 60 m². 2 / g or more, The mesopore volume of the ruthenium-supported catalyst is 0.15 mL / g or more. A method for producing aliphatic aldehydes.

2. The method for producing a product according to claim 1, wherein the aliphatic primary alcohol is an aliphatic linear saturated primary alcohol.

3. The manufacturing method according to claim 1, wherein the porous oxide is one or more selected from the group consisting of alumina, titania, zirconia, silica, silicaalumina, magnesia, zeolite, and activated carbon.

4. The surface area per unit mass of the ruthenium is 65 m². 2 / g or more 250m 2 The manufacturing method according to claim 1, wherein the amount is less than or equal to / g.

5. The manufacturing method according to claim 1, wherein the mesopore volume is 0.2 mL / g or more and 0.5 mL / g or less.

6. The manufacturing method according to claim 1, wherein the molar ratio of ruthenium (mol) to aliphatic primary alcohol (mol) is 0.001 or more and 0.2 or less.

7. The manufacturing method according to claim 1, wherein the temperature of the oxidation step is 60°C or higher and 200°C or lower.

8. The surface area per unit mass of the ruthenium is 70 m 2 / g or more 190m 2 The manufacturing method according to claim 1, wherein the amount is less than or equal to / g.

9. The method for producing the product according to claim 1, wherein the aliphatic primary alcohol having 4 or more carbon atoms is an aliphatic linear saturated primary alcohol having 8 to 14 carbon atoms.

10. The manufacturing method according to claim 1, wherein the ruthenium metal content in the ruthenium-supported catalyst is 1% by mass or more and less than 10% by mass.

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