JP5340705B2 - Method for producing noble metal-containing catalyst, and method for producing α, β-unsaturated carboxylic acid and α, β-unsaturated carboxylic acid anhydride - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a noble metal-containing catalyst to be used for producing &alpha;,&beta;-unsaturated carboxylic acid and &alpha;,&beta;-unsaturated carboxylic anhydride from olefin with high selectivity and with high productivity and a method for producing &alpha;,&beta;-unsaturated carboxylic acid and &alpha;,&beta;-unsaturated carboxylic anhydride with high selectivity and with high productivity. <P>SOLUTION: The method for manufacturing the noble metal-containing catalyst comprises the steps of: drying a raw material solution containing a noble metal component, an inorganic solvent and organic matter to obtain a catalyst precursor; and reducing the catalyst precursor. Olefin is oxidized in a liquid phase by molecular oxygen in the presence of the noble metal-containing catalyst to produce &alpha;,&beta;-unsaturated carboxylic acid and &alpha;,&beta;-unsaturated carboxylic anhydride. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a noble metal-containing catalyst for producing an α, β-unsaturated carboxylic acid and an α, β-unsaturated carboxylic acid anhydride from an olefin, a method for producing the same, and an α, β-unsaturated carboxylic acid using the same. And a process for producing an α, β-unsaturated carboxylic acid anhydride.

As a noble metal-containing catalyst for producing an α, β-unsaturated carboxylic acid by liquid phase oxidation of olefin with molecular oxygen, for example, Patent Document 1 discloses a palladium-containing catalyst. As a method for producing a noble metal-containing catalyst, Patent Document 2 discloses a method in which palladium acetate is dissolved in acetic acid and calcined at a temperature equal to or higher than the thermal decomposition temperature. Patent Document 3 discloses a method using 20% by mass acetic acid in palladium acetate as a solvent. A method of adding a silica carrier and adding allyl alcohol as a reducing agent is described.
International Publication No. 2005/118134 Pamphlet JP 2006-167709 A JP 2005-218952 A

  However, even if the noble metal-containing catalyst described in Patent Documents 1 to 3 is used in the liquid phase oxidation reaction for the production of α, β-unsaturated carboxylic acid and α, β-unsaturated carboxylic acid anhydride, the target product The selectivity and productivity are not always sufficient, and further improvement in catalyst performance is desired.

Therefore, the present invention provides a method for producing a noble metal-containing catalyst capable of producing α, β-unsaturated carboxylic acid and α, β-unsaturated carboxylic acid anhydride from olefin with high selectivity and high productivity, and α, β. An object of the present invention is to provide a method for producing an unsaturated carboxylic acid and an α, β-unsaturated carboxylic acid anhydride with high selectivity and high productivity.

The present invention relates to a method for producing a noble metal-containing catalyst for producing an α, β-unsaturated carboxylic acid and an α, β-unsaturated carboxylic acid anhydride from an olefin, which comprises propionic acid, 1,4-dioxane, methyl isobutyl ketone, 3-methoxy-1-butanol, at least one organic substance selected from the group consisting of ethylene glycol and glycerine, a raw material solution containing a precious metal component and inorganic solvent was immersed or impregnated in a carrier, drying the raw material solution Thus, there is provided a method for producing a noble metal-containing catalyst comprising a step of obtaining a catalyst precursor, a step of heat-treating the catalyst precursor, and a step of reducing the catalyst precursor.

  The present invention also provides a process for producing an α, β-unsaturated carboxylic acid and an α, β-unsaturated carboxylic acid anhydride, wherein an olefin is oxidized in the liquid phase with molecular oxygen in the presence of the noble metal-containing catalyst. It is.

According to the present invention, the olefin alpha, beta-unsaturated carboxylic acids and alpha, beta-method of manufacturing a touch noble metal-containing manufacturable medium an unsaturated carboxylic acid anhydride with high selectivity and high productivity, as well as alpha, It is possible to provide a method for producing a β-unsaturated carboxylic acid and an α, β-unsaturated carboxylic acid anhydride with high selectivity and high productivity.

  The noble metal-containing catalyst of the present invention is a noble metal-containing catalyst for producing α, β-unsaturated carboxylic acid and α, β-unsaturated carboxylic acid anhydride from olefin with high selectivity and high productivity (hereinafter simply referred to as “ Sometimes referred to as "catalyst").

  Examples of the noble metal of the noble metal-containing catalyst of the present invention include palladium, platinum, rhodium, ruthenium, iridium, gold, silver, and osmium. Of these, palladium, platinum, rhodium, ruthenium, iridium and gold are preferable, and palladium is particularly preferable. 1 type can also be used for a noble metal and it can also use 2 or more types together.

  The noble metal-containing catalyst of the present invention is not particularly limited, but preferably contains a metal other than the noble metal. Examples of the metal other than the noble metal include antimony, tellurium, thallium, lead, bismuth and the like. Two or more metals other than the noble metals can be included. From the viewpoint of developing high catalytic activity, it is preferable that 50% by mass or more of the metal contained in the noble metal-containing catalyst is a noble metal.

The noble metal-containing catalyst of the present invention may be an unsupported type, but is preferably a supported type in which a noble metal is supported on a carrier. As the carrier, an inorganic oxide can be used, and examples thereof include silica, alumina, magnesia, calcia, titania and zirconia. Of these, silica, titania and zirconia are preferably used. One type of carrier can be used, or two or more types can be used in combination. The preferred specific surface area of the support varies depending on the type of the support and the like, and thus cannot be generally stated. In the case of silica, 50 to 1500 m ² / g is preferable, and 100 to 1000 m ² / g is more preferable. When the specific surface area of the carrier is small, the useful component is more supported on the surface, and when the specific surface area is large, the useful component is supported on both the inside and the surface, and the support rate of the useful component is increased.

  The loading ratio of the noble metal to the carrier is preferably 0.1 to 40% by mass, more preferably 0.5 to 30% by mass, and further preferably 1 to 20% by mass with respect to the mass of the carrier before loading.

  In producing the noble metal-containing catalyst of the present invention, first, a raw material solution containing a noble metal component, an inorganic solvent and an organic substance is prepared.

  Although the noble metal component to be used is not particularly limited, for example, a noble metal in a metal state, a noble metal oxide, or a noble metal salt is used. Of these, noble metal salts such as chlorides, nitrates and sulfates are preferred.

  As the inorganic solvent to be used, water and inorganic acids can be used. Examples of inorganic acids include nitric acid, hydrochloric acid and sulfuric acid.

  Although the organic substance to be used is not particularly limited, an organic solvent having a boiling point of 300 ° C. or lower is preferably used, and an organic solvent having a boiling point of 200 ° C. or lower is more preferable. Specifically, alcohols, ketones, ethers, organic acids, organic acid esters, hydrocarbons and the like can be used. Examples of alcohols include methanol, 2-butanol, tertiary butanol, 2-ethoxyethanol, 3-methoxy-1-butanol, ethylene glycol, propylene glycol, and glycerin. Examples of ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of ethers include dimethyl ether, 1,4-dioxane, ethylene oxide and the like. Examples of organic acids include acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid and the like. Examples of the organic acid esters include ethyl acetate and methyl propionate. Examples of hydrocarbons include hexane, cyclohexane, and toluene. Of these, alcohols, ketones, ethers, and organic acids are preferably used. Acetic acid, propionic acid, 2-butanol, dioxane, methyl isobutyl ketone, 2-ethoxyethanol, 3-methoxy-1-butanol, ethylene glycol And glycerin is particularly preferred. One type of organic substance can be used, or two or more types can be used in combination.

  The method of preparing the raw material solution containing the noble metal component, the inorganic solvent and the organic material is not particularly limited, but the method of mixing the organic material into the solution in which the noble metal component is dissolved in the inorganic solvent, the solution in which the noble metal component is dissolved in the organic material such as the organic solvent. Examples thereof include a method of mixing an inorganic solvent, a method of dissolving a noble metal component in a solution in which an inorganic solvent and an organic substance are mixed.

  The mixing ratio of the inorganic solvent and the organic substance in the raw material solution is not particularly limited, but the mass ratio of the inorganic solvent and the organic substance is preferably 50: 1 to 1: 100, and more preferably 40: 1 to 1:50.

  Although the density | concentration of the noble metal component in a raw material solution is not specifically limited, 0.5-20 mass% is preferable and 1.0-10 mass% is more preferable.

  When a supported noble metal-containing catalyst is produced, the raw material solution may be immersed or impregnated in the support in order to support the noble metal on the support. In this case, the amount (volume) of the raw material solution used varies depending on the pore volume, hydrophilicity / hydrophobicity, etc. of the carrier used, but it cannot be generally stated, but is preferably 1.0 to 10 times the pore volume of the carrier. 2.0 to 7.0 times is more preferable.

  By including an organic substance in the raw material solution as described above, the surface tension of the raw material solution is lowered, and the noble metal particles in the catalyst are finely divided and highly dispersed on the support. When the organic substance is added, the particle size of the noble metal particles in the catalyst is reduced by about 20 to 50% compared to the case where the organic substance is not added. As a result, a catalyst capable of producing an α, β-unsaturated carboxylic acid and an α, β-unsaturated carboxylic acid anhydride with high selectivity and high productivity can be obtained.

  When producing a noble metal-containing catalyst containing a metal other than a noble metal, a corresponding metal or a metal component such as a salt or oxide thereof may be present in the raw material solution. Examples of the method include a method in which a metal component other than a noble metal coexists in a raw material solution, and a method in which an organic substance is mixed after a metal component other than a noble metal coexists in a solution in which a noble metal component is dissolved in an inorganic solvent. Not. In the latter method, the mixing ratio of a solution in which a metal other than the noble metal coexists in a solution in which a noble metal component is dissolved in an inorganic solvent and the organic substance is not particularly limited, but the mass ratio of the solution to the organic substance is 50: 1 to 1: 100 is preferable and 40: 1 to 1:50 is more preferable.

  The supporting method for supporting a metal other than the noble metal on the carrier is not particularly limited, but can be performed in the same manner as the method for supporting the noble metal. Further, the metal other than the noble metal can be supported before the noble metal is supported, can be supported after the noble metal is supported, or can be supported simultaneously with the noble metal.

  After preparing the raw material solution, the raw material solution is dried to obtain a catalyst precursor obtained by evaporating the solvent in the raw material solution. When producing a supported noble metal-containing catalyst, the raw material solution is dipped or impregnated in a carrier and then dried. Examples of the drying method include a method of drying at normal pressure and high temperature, and a method of drying at low pressure and low temperature, but under reduced pressure (for example, -0.2 to -0.001 MPa; hereinafter, pressure is expressed in gauge pressure), 30 It is preferable to dry at ~ 80 ° C for 2 to 5 hours.

  After drying, it is preferable to heat-treat the catalyst precursor. When a noble metal salt is used by heat treatment, the noble metal salt is decomposed to obtain a noble metal oxide. The temperature of the heat treatment is preferably higher than the thermal decomposition temperature of the noble metal salt and higher than the evaporation or decomposition temperature of the organic matter. The temperature of the heat treatment varies depending on the type of noble metal salt used, and cannot be generally specified, but is preferably about 150 to 600 ° C., and the rate of temperature rise is preferably 1 to 10 ° C./min. The heat treatment time is not particularly limited as long as the noble metal salt becomes a noble metal oxide, but is preferably 1 to 12 hours.

  A noble metal-containing catalyst can be obtained by reducing the catalyst precursor produced as described above.

  The reducing agent used for reducing the catalyst precursor is not particularly limited. For example, hydrazine, formaldehyde, sodium borohydride, hydrogen, formic acid, formic acid salt, ethylene, propylene, 1-butene, 2-butene, isobutylene, 1, Examples include 3-butadiene, 1-heptene, 2-heptene, 1-hexene, 2-hexene, cyclohexene, ethylene glycol, allyl alcohol, methallyl alcohol, acrolein, and methacrolein. Of these, hydrogen, hydrazine, formaldehyde, formic acid, and ethylene glycol are preferable. Two or more of these may be used in combination.

  The method for reducing the catalyst precursor may be a liquid phase reduction method in which a catalyst precursor dissolved or dispersed in a solvent is reduced with a reducing agent, or a gas phase reduction method in which a solid of the catalyst precursor is reduced in a reducing atmosphere. Of these, the liquid phase reduction method is preferred.

  The solvent used for the reduction in the liquid phase is preferably water, but depending on the dispersibility of the carrier, alcohols such as ethanol, 1-propanol, 2-propanol, n-butanol, t-butanol, ethylene glycol, etc. Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; organic acids such as acetic acid, n-valeric acid and isovaleric acid; and organic solvents such as hydrocarbons such as heptane, hexane and cyclohexane alone or in combination Can be used. A mixed solvent of these and water can also be used.

  When the reducing agent is a gas, it is preferably carried out in a pressurizing apparatus such as an autoclave in order to increase the solubility in the solution. At that time, the inside of the pressurizer is pressurized with a reducing agent. The pressure is preferably 0.1 MPa or more, and preferably 1.0 MPa or less.

  When the reducing agent is a liquid, there is no limitation on the apparatus for reducing the noble metal, and the reducing agent can be added to the solution. The amount of the reducing agent used at this time is not particularly limited, but it is preferably 1 mol or more and 1 mol or less with respect to 1 mol of the noble metal.

  Although the reduction temperature and reduction time vary depending on the precious metal and reducing agent used, the reduction temperature is preferably -5 to 150 ° C, more preferably 15 to 80 ° C. The reduction time is preferably 0.1 to 4 hours, more preferably 0.25 to 4 hours, and further preferably 0.5 to 3 hours.

  During the reduction, ultrasonic treatment can be performed in a state where the catalyst precursor is dispersed.

  The obtained noble metal-containing catalyst is preferably washed with water, an organic solvent or the like. By washing with water, an organic solvent, or the like, impurities derived from noble metal compounds such as chloride, acetate radical, nitrate radical, and sulfate radical are removed. The cleaning method and the number of times are not particularly limited. However, depending on the impurities, there is a possibility that the liquid phase oxidation reaction of the olefin may be inhibited. The washed catalyst may be used for the reaction as it is after being recovered by filtration or centrifugation.

  Further, the recovered catalyst may be dried. Although a drying method is not specifically limited, It is preferable to dry in air or an inert gas using a dryer. The dried catalyst can also be activated before use in the reaction if desired. The activation method is not particularly limited, and examples thereof include a heat treatment method in a reducing atmosphere in a hydrogen stream. According to this method, the oxide film on the surface of the noble metal and impurities that could not be removed by cleaning can be removed.

  The physical properties of the obtained noble metal-containing catalyst can be confirmed by BET specific surface area measurement, XRD measurement, CO pulse adsorption method, TEM observation and the like.

  Next, a method for producing an α, β-unsaturated carboxylic acid and an α, β-unsaturated carboxylic acid anhydride using the noble metal-containing catalyst of the present invention will be described. As a method for producing an α, β-unsaturated carboxylic acid and an α, β-unsaturated carboxylic acid anhydride, an olefin as a raw material is oxidized with molecular oxygen in a liquid phase, and an α, β-unsaturated carboxylic acid is obtained. A method in which the reaction to form an acid and an α, β-unsaturated carboxylic acid anhydride is performed in the presence of the noble metal-containing catalyst of the present invention is preferred. According to such a method, α, β-unsaturated carboxylic acid and α, β-unsaturated carboxylic acid anhydride can be produced with high selectivity and high productivity.

  Examples of the olefin include propylene, isobutylene and 2-butene. Of these, propylene and isobutylene are preferred. The raw olefin may contain a small amount of saturated hydrocarbon and / or lower saturated aldehyde as impurities.

  The produced α, β-unsaturated carboxylic acid is an α, β-unsaturated carboxylic acid having the same carbon skeleton as the olefin, and the produced α, β-unsaturated carboxylic acid is an α, β -A compound obtained by dehydration condensation of two molecules of unsaturated carboxylic acid. Specifically, when the raw material is propylene, acrylic acid and acrylic anhydride are obtained, and when the raw material is isobutylene, methacrylic acid and methacrylic anhydride are obtained.

  The noble metal-containing catalyst of the present invention is particularly suitable for liquid phase oxidation for producing acrylic acid and acrylic anhydride from propylene and methacrylic acid and methacrylic anhydride from isobutylene.

  As the molecular oxygen source used in the liquid phase oxidation reaction, air is economical and preferable, but pure oxygen or a mixed gas of pure oxygen and air can also be used, and if necessary, air or pure oxygen is nitrogen, A mixed gas diluted with carbon dioxide, water vapor or the like can also be used. This gas such as air is usually supplied in a pressurized state into a reaction vessel such as an autoclave.

  The solvent used for the liquid phase oxidation reaction is not particularly limited. For example, water, alcohols, ketones, organic acids, organic acid esters, hydrocarbons and the like can be used. Examples of alcohols include tertiary butanol and cyclohexanol. Examples of ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of organic acids include acetic acid, propionic acid, n-butyric acid, isobutyric acid, n-valeric acid, isovaleric acid and the like. Examples of the organic acid esters include ethyl acetate and methyl propionate. Examples of hydrocarbons include hexane, cyclohexane, and toluene. Of these, organic acids having 2 to 6 carbon atoms, ketones having 3 to 6 carbon atoms, and tertiary butanol are preferable. The solvent may be one kind or a mixed solvent of two or more kinds. Moreover, when using at least 1 sort (s) chosen from the group which consists of alcohols, ketones, organic acids, and organic acid esters, it is preferable to use it as a mixed solvent with water. Although the amount of water at that time is not particularly limited, it is preferably 2 to 70% by mass and more preferably 5 to 50% by mass with respect to the mass of the mixed solvent. The mixed solvent is desirably uniform, but may be used in a non-uniform state.

  The liquid phase oxidation reaction may be carried out in either a continuous type or a batch type, but in view of productivity, the continuous type is preferred industrially.

  0.1-20 mass parts is preferable with respect to 100 mass parts of solvent, and, as for the usage-amount of the olefin which is a raw material of a liquid phase oxidation reaction, 0.5-10 mass parts is more preferable.

  The amount of molecular oxygen used is preferably from 0.1 to 30 mol, more preferably from 0.3 to 25 mol, particularly preferably from 0.5 to 20 mol, based on 1 mol of the raw material olefin.

  Usually, the catalyst is used in a state of being suspended in a reaction solution for performing a liquid phase oxidation reaction, but may be used in a fixed bed. The amount of the catalyst used is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight as the catalyst present in the reactor with respect to 100 parts by weight of the solution present in the reactor. ˜15 parts by mass is particularly preferred.

  The temperature and pressure at which the liquid phase oxidation reaction is performed are appropriately selected depending on the solvent and the raw material used. The reaction temperature is preferably 30 to 200 ° C, more preferably 50 to 150 ° C. The reaction pressure is preferably 0 to 10 MPa, and more preferably 2 to 7 MPa.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to an Example. The “parts” in the following examples and comparative examples are parts by mass.

(Analysis of raw materials and products in the production of α, β-unsaturated carboxylic acid and α, β-unsaturated carboxylic acid anhydride)
Analysis of raw materials and products in the production of α, β-unsaturated carboxylic acid and α, β-unsaturated carboxylic acid anhydride was performed using gas chromatography. In addition, reaction rate of olefin (raw material), selectivity and productivity of α, β-unsaturated aldehyde (byproduct) to be produced, α, β-unsaturated carboxylic acid to be produced and α, β-unsaturated carboxylic acid anhydride The selectivity and productivity of a product (target product) are defined as follows.
Olefin reaction rate (%) = (B / A) × 100
Selectivity of α, β-unsaturated aldehyde (%) = (C / B) × 100
Selectivity of α, β-unsaturated carboxylic acid (%) = (D / B) × 100
Selectivity of α, β-unsaturated carboxylic anhydride (%) = (E / B) × 100
Selectivity (%) of α, β-unsaturated carboxylic acid and α, β-unsaturated carboxylic anhydride
= ((D + E) / B) × 100
Productivity of α, β-unsaturated aldehyde (g-MAL / (g-noble metal × h))
= F / (G x H)
Productivity of α, β-unsaturated carboxylic acid (g-MAA / (g-noble metal × h))
= I / (G × H)
Productivity of α, β-unsaturated carboxylic acid anhydride (g-MAAanh / (g-noble metal × h)) = J / (G × H)
Productivity of α, β-unsaturated carboxylic acid and α, β-unsaturated carboxylic acid anhydride ((g-MAA + MAAanh) / (g-noble metal × h)) = (I + J) / (G × H)
Here, A is the number of moles of olefin supplied, B is the number of moles of reacted olefin, C is the number of moles of α, β-unsaturated aldehyde produced, and D is the mole of α, β-unsaturated carboxylic acid produced. Number, E is the number of moles of the α, β-unsaturated carboxylic acid anhydride formed, F is the mass of the α, β-unsaturated aldehyde formed (g), and G is the mass of the noble metal contained in the catalyst used. (G), H is the reaction time (h), I is the mass (g) of the produced α, β-unsaturated carboxylic acid, and J is the mass (g) of the produced α, β-unsaturated carboxylic acid anhydride. is there.

[ Reference Example 1 ]
(Catalyst preparation)
An aqueous palladium nitrate solution (manufactured by NE Chemcat, palladium content: 23.3 mass%) is diluted with 4.3 parts of pure water, and at 20 ° C., 0.5 parts of acetic acid as an organic substance is diluted. In addition, a palladium solution (raw material solution) was prepared. To this palladium solution is added 5.0 parts of a silica carrier (specific surface area 760 m ² / g, pore volume 1.05 cc / g), dried under reduced pressure (about −0.02 MPa) at 50 ° C. for 2 hours, and then Firing was performed at 300 ° C. for 3 hours under atmospheric flow.

  The obtained solid was added to 20.0 parts of ethylene glycol and subjected to reduction treatment at 80 ° C. for 2 hours. Thereafter, the product was washed and filtered with pure water to obtain a silica-supported palladium catalyst. The palladium loading of this catalyst is 16% by mass.

(Reaction evaluation)
In an autoclave, 0.6 part of the silica-supported palladium catalyst obtained by the above method and 75 parts of a 75 mass% t-butanol aqueous solution as a reaction solvent were placed, and the autoclave was sealed. Next, 2.0 parts of isobutylene was introduced into the autoclave, stirring (rotation speed: 1000 rpm) was started, and the temperature was raised to 100 ° C. After completion of the temperature increase, nitrogen was introduced into the autoclave to an internal pressure of 2.4 MPa, and then compressed air was introduced to an internal pressure of 4.8 MPa, and a liquid phase oxidation reaction of isobutylene was performed for 30 minutes.

  After completion of the reaction, the inside of the autoclave was ice-cooled in an ice bath. A gas collection bag was attached to the gas outlet of the autoclave, and the pressure in the reactor was released while collecting the gas that was opened by opening the gas outlet. The reaction solution containing the catalyst was taken out from the autoclave, the catalyst was separated by a membrane filter, and only the reaction solution was recovered. The collected reaction liquid and the collected gas were analyzed by gas chromatography.

[ Reference Example 2 ]
A silica-supported palladium catalyst was prepared in the same manner as in Reference Example 1 except that 2-butanol was used as the organic substance. The reaction was evaluated in the same manner as in Reference Example 1 except that this catalyst was used.

[Example 3]
A silica-supported palladium catalyst was prepared in the same manner as in Reference Example 1 except that propionic acid was used as the organic substance. The reaction was evaluated in the same manner as in Reference Example 1 except that this catalyst was used.

[ Reference Example 3 ]
(Catalyst preparation)
A palladium solution was prepared by diluting 4.3 parts of an aqueous palladium nitrate solution (manufactured by NE Chemcat, palladium content: 23.3 mass%) with 5.6 parts of pure water. To this palladium solution, after adding a tellurium solution in which 0.10 parts of telluric acid (manufactured by Wako Pure Chemical Industries) was dissolved in 5 parts of pure water, at 20 ° C., 0.5 parts of acetic acid as an organic substance was added, A palladium-tellurium solution (raw material solution) was prepared. Thereafter, 5.0 parts of silica support was added in the same manner as in Reference Example 1 , dried under reduced pressure (−0.02 MPa) at 50 ° C. for 2 hours, and then calcined at 300 ° C. for 3 hours under atmospheric flow.

  The obtained solid was added to 20.0 parts of ethylene glycol and subjected to reduction treatment at 80 ° C. for 2 hours. Thereafter, the resultant was washed and filtered with pure water to obtain a silica-supported palladium-tellurium catalyst. The palladium loading of this catalyst was 16% by mass, and Te / Pd (mass ratio) in the catalyst was 0.06.

(Reaction evaluation)
The same method as in Reference Example 1 was performed.

[Example 5]
A silica-supported palladium-tellurium catalyst was prepared in the same manner as in Reference Example 3 except that 1,4-dioxane was used as the organic substance. The reaction was evaluated in the same manner as in Reference Example 1 except that this catalyst was used.

[Example 6]
A silica-supported palladium-tellurium catalyst was prepared in the same manner as in Reference Example 3 except that methyl isobutyl ketone was used as the organic substance. The reaction was evaluated in the same manner as in Reference Example 1 except that this catalyst was used.

[Example 7]
A silica-supported palladium-tellurium catalyst was prepared in the same manner as in Reference Example 3 except that 10 parts of 1,4-dioxane was added as an organic substance without diluting the aqueous palladium nitrate solution with pure water. The reaction was evaluated in the same manner as in Reference Example 1 except that this catalyst was used.

[ Reference Example 4 ]
A silica-supported palladium-tellurium catalyst was prepared in the same manner as in Reference Example 3 except that 2-ethoxyethanol was used as the organic substance. The reaction was evaluated in the same manner as in Reference Example 1 except that this catalyst was used.

[Example 9]
A silica-supported palladium-tellurium catalyst was prepared in the same manner as in Reference Example 3 except that 3-methoxy-1-butanol was used as the organic substance. The reaction was evaluated in the same manner as in Reference Example 1 except that this catalyst was used.

[Example 10]
A silica-supported palladium-tellurium catalyst was prepared in the same manner as in Reference Example 3 except that 0.1 part of ethylene glycol was used as the organic substance. The reaction was evaluated in the same manner as in Reference Example 1 except that this catalyst was used.

[Example 11]
A silica-supported palladium-tellurium catalyst was prepared in the same manner as in Reference Example 3 except that 0.1 part of glycerin was used as the organic substance. The reaction was evaluated in the same manner as in Reference Example 1 except that this catalyst was used.

[Comparative Example 1]
A silica-supported palladium catalyst was prepared in the same manner as in Reference Example 1 except that no organic substance was added. The reaction was evaluated in the same manner as in Reference Example 1 except that this catalyst was used.

[Comparative Example 2]
(Catalyst preparation)
An acetic acid solution was prepared by dissolving 2.2 parts of palladium (II) acetate (manufactured by NE Chemcat) in 20.0 parts of acetic acid. The acetic acid solution was added little by little to 20.0 parts of silica support (specific surface area 760 m ² / g, pore volume 1.05 cc / g), and shaking was repeated. Next, it was dried at 50 ° C. for 2 hours under reduced pressure (about −0.02 MPa), and then calcined at 300 ° C. for 3 hours under atmospheric flow.

  The obtained solid was added to 80.0 parts of ethylene glycol and subjected to reduction treatment at 80 ° C. for 2 hours. Thereafter, the product was washed and filtered with pure water to obtain a silica-supported palladium catalyst. The palladium loading of this catalyst is 4.8% by mass.

(Reaction evaluation)
The reaction was evaluated in the same manner as in Reference Example 1 except that 2.1 parts of this catalyst was used.

[Comparative Example 3]
A silica-supported palladium catalyst was prepared in the same manner as in Reference Example 3 except that no organic substance was added. The reaction was evaluated in the same manner as in Reference Example 1 except that this catalyst was used.

  The above reaction evaluation results are shown in Tables 1 and 2. It was found that by using the noble metal-containing catalyst of the present invention, methacrylic acid and methacrylic anhydride can be produced with high selectivity and high productivity.

Claims (2)

A process for producing a noble metal-containing catalyst for producing an α, β-unsaturated carboxylic acid and an α, β-unsaturated carboxylic acid anhydride from an olefin,
Propionic acid, 1,4-dioxane, dipping methyl isobutyl ketone, 3-methoxy-1-butanol, at least one organic substance selected from the group consisting of ethylene glycol and glycerine, a raw material solution containing a precious metal component and inorganic Solvent the carrier Or impregnating and drying the raw material solution to obtain a catalyst precursor;
Heat-treating the catalyst precursor;
A method for producing a noble metal-containing catalyst comprising a step of reducing the catalyst precursor. To produce a precious metal-containing catalyst in the process according to claim 1, wherein, in the presence of that, oxidized in a liquid phase an olefin with molecular oxygen alpha, beta-unsaturated carboxylic acids and alpha, beta-unsaturated carboxylic acid Method for producing anhydride.