JP2008068228A - Method of manufacturing palladium-containing supported catalyst - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a palladium-containing catalyst for manufacturing α,β-unsaturated carboxylic acids from olefins or α,β-unsaturated aldehydes with high productivity, a method of manufacturing the catalyst and a method of manufacturing α,β-unsaturated carboxylic acids with high productivity. <P>SOLUTION: The palladium-containing supported catalyst for manufacturing α,β-unsaturated carboxylic acids from olefins or α,β-unsaturated aldehydes is manufactured by a method having (a) the process of causing a palladium salt to be carried in a support, (b) the process of hydrolyzing a metal compound having hydrolyzable functional groups in a mass ratio of the metal compound to the support of 0.01-0.25 in a water-containing solution and (c) the process of carrying out dehydration condensation the product obtained in the process (b) by the hydrolysis, in the presence of the support. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a palladium-containing supported catalyst for producing an α, β-unsaturated carboxylic acid from an olefin or an α, β-unsaturated aldehyde. The present invention also relates to a method for producing an α, β-unsaturated carboxylic acid.

As a palladium-containing supported 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 supported catalyst of palladium metal obtained by reducing a palladium salt with a reducing agent. Has been proposed.
International Publication No. 02/083299 Pamphlet

  However, the productivity of α, β-unsaturated carboxylic acid when using the catalyst produced by the method described in Patent Document 1 is not yet sufficient, and is more productive for producing α, β-unsaturated carboxylic acid. A catalyst is desired.

  Accordingly, an object of the present invention is to provide a palladium-containing catalyst for producing an α, β-unsaturated carboxylic acid from an olefin or an α, β-unsaturated aldehyde with high productivity, a method for producing the catalyst, and an α, β-unsaturated product. The object is to provide a method for producing a saturated carboxylic acid with high productivity.

The present invention is a method for producing a palladium-containing supported catalyst for producing an α, β-unsaturated carboxylic acid from an olefin or an α, β-unsaturated aldehyde,
(A) supporting a palladium salt on a carrier;
(B) a step of hydrolyzing a metal compound having a hydrolyzable functional group having a mass ratio of 0.01 to 0.25 with respect to the carrier in a water-containing solution;
(C) subjecting the product obtained by the hydrolysis reaction in the step (b) to a dehydration condensation reaction in the presence of the carrier;
It is a manufacturing method of the palladium containing supported catalyst characterized by having.

  In the method for producing the palladium-containing supported catalyst, it is preferable that the step (a) and the step (c) are performed simultaneously, or the step (c) is performed after the step (a).

  Moreover, this invention is a palladium containing supported catalyst obtained by the said manufacturing method.

  Furthermore, the present invention is a method for producing an α, β-unsaturated carboxylic acid in which an olefin or an α, β-unsaturated aldehyde is subjected to liquid phase oxidation with molecular oxygen using the palladium-containing supported catalyst.

  According to the method for producing a palladium-containing supported catalyst of the present invention, when α, β-unsaturated carboxylic acid is produced from olefin or α, β-unsaturated aldehyde, α, β-unsaturated carboxylic acid is highly productive. A palladium-containing supported catalyst that can be produced by the above process can be produced.

  Further, according to the palladium-containing supported catalyst of the present invention, when α, β-unsaturated carboxylic acid is produced from olefin or α, β-unsaturated aldehyde, α, β-unsaturated carboxylic acid is produced with high productivity. Can be manufactured.

  Furthermore, according to the method for producing an α, β-unsaturated carboxylic acid of the present invention, an α, β-unsaturated carboxylic acid can be produced with high productivity.

The method for producing a palladium-containing supported catalyst of the present invention is a method for producing a palladium-containing supported catalyst for producing an α, β-unsaturated carboxylic acid from an olefin or an α, β-unsaturated aldehyde, comprising the following steps: Have.
(A) A step of supporting a palladium salt on a carrier.
(B) A step of hydrolyzing a metal compound having a hydrolyzable functional group having a mass ratio of 0.01 to 0.25 with respect to the carrier in a water-containing solution.
(C) A step of subjecting the product obtained by the hydrolysis reaction in the step (b) to a dehydration condensation reaction in the presence of the carrier.

  Factors that can produce an α, β-unsaturated carboxylic acid with high productivity are the stabilization of palladium particles on the carrier by hydrolysis and dehydration condensation of a metal compound having a hydrolyzable functional group. It is conceivable that the characteristics of the surface of the carrier are changed by the metal compound having a hydrolyzable functional group, and the interaction between the palladium particles and the carrier is improved.

  The palladium-containing supported catalyst of the present invention is a supported catalyst in which a catalyst constituent element containing palladium metal is supported on a carrier, and can be obtained, for example, by the following production method. However, if the obtained palladium containing supported catalyst is the same, it is not limited to what was manufactured with the following manufacturing method.

  The carrier is not particularly limited. Examples thereof include silica, alumina, silica alumina, magnesia, calcia, titania, zirconia and activated carbon. Of these, silica, alumina, titania and zirconia are preferable. One type of carrier can be used, or two or more types can be used in combination. The carrier is preferably porous.

Although specific surface area of the support can not be said sweepingly because different by the kind of carrier, the case of silica, preferably at least ^{50m 2 / g, 100m 2 /} g or more is more preferable. Moreover, 1500 m < ² > / g or less is preferable and 1000 m < ² > / g or less is more preferable. The smaller the specific surface area of the carrier, the more the catalyst having a useful component supported on the surface can be produced, and the larger the specific surface area of the carrier, the more the useful component supported. The pore volume of the carrier is preferably 0.05 to 2.0 cc / g from the viewpoint of the strength of the carrier and the efficiency of palladium loading.

  Examples of the palladium salt include palladium (II) chloride, palladium (II) acetate, palladium (II) nitrate, tetraammine palladium nitrate (II), bis (acetylacetonato) palladium (II), and the like. Of these, palladium (II) acetate, palladium (II) nitrate, tetraammine palladium nitrate (II), and bis (acetylacetonato) palladium (II) are preferred. One palladium salt can be used, or two or more palladium salts can be used in combination.

  The method for supporting the palladium salt on the carrier is not particularly limited, but the method of evaporating the solvent after immersing the carrier in the palladium salt solution, or absorbing the palladium salt solution for the pore volume of the carrier into the carrier. A so-called pore filling method, in which the solvent is evaporated after that, is preferable. The solvent for dissolving the palladium salt is not particularly limited as long as it dissolves the palladium salt.

  As the metal compound having a hydrolyzable functional group, a metal alkoxide or an oligomer thereof can be used. As an alkoxy group which forms a metal alkoxide, a C1-C3 thing, such as a methoxy group, an ethoxy group, a propoxy group, is preferable, for example. Moreover, as a metal which forms a metal alkoxide, the metal corresponding to the metal oxide finally formed, for example, silicon, titanium, zirconium, aluminum, is used. This metal may be one type or two or more types. On the other hand, it does not specifically limit as an oligomer, About 10-mer can be used conveniently.

  In addition, when the metal is silicon, alkylalkoxysilanes in which a part of the alkoxy group of silicon alkoxide or its oligomer is substituted with an alkyl group, and a crosslinked alkoxide in which two or more silicons are linked by a crosslinked structure mainly composed of hydrocarbons And oligomers of up to about 10-mers thereof are also preferably used. In addition, an alkyl-substituted metal alkoxide in which a metal is replaced with titanium, zirconia, aluminum, or the like instead of silicon can also be used.

  The amount of the metal compound having a hydrolyzable functional group is in the range of 0.01 to 0.25 by mass ratio with respect to the support. When the mass ratio is 0.01 or less, a sufficient effect cannot be obtained, and when the mass ratio is 0.25 or more, pores are blocked in the support, the palladium metal surface is covered, and the effect is not obtained. Preferably, it is 0.02 or more by mass ratio, More preferably, it is 0.03 or more. Further, the mass ratio is preferably 0.2 or less, and more preferably 0.15 or less.

Hydrolysis reaction conditions for the metal compound having a hydrolyzable functional group are not particularly limited. For example, the hydrolysis reaction is performed by mixing 4 mol or more of water with 1 mol of the metal compound having a hydrolyzable functional group. Can be carried out, whereby a hydrolyzate can be obtained. Further, if necessary, an organic solvent may be mixed. The hydrolysis reaction is preferably performed under acidic conditions of pH 1-5. The treatment time for the hydrolysis reaction is preferably 0.5 to 2 hours, and the treatment temperature is preferably 10 to 60 ° C. When the metal compound having a hydrolyzable functional group is a metal alkoxide, the progress of the hydrolysis reaction is to observe the spectrum derived from the metal alkoxide and the spectrum derived from the alcohol generated by hydrolysis using ¹ H-NMR. Etc. can be confirmed.

  Next, a dehydration condensation reaction of the hydrolyzate is performed. Since this dehydration condensation reaction is carried out in the presence of a carrier, the carrier is added during the hydrolysis reaction or after the hydrolysis reaction. The method for the dehydration condensation reaction of the hydrolyzate is not particularly limited, and various methods can be used. Examples thereof include a method by pH adjustment by addition of alkali, a method by heating, a method by addition of a dehydration condensation catalyst, and a method by removal of a solvent. In the present invention, it is preferable to carry out a dehydration condensation reaction of the hydrolyzate by evaporating water and the organic solvent.

  The step of supporting the palladium salt on the carrier and the step of dehydrating and condensing the hydrolyzate in the presence of the carrier can be performed separately or simultaneously. Since it is considered that the palladium salt is stabilized by dehydration condensation of the metal hydroxide with the hydroxyl group on the support surface around the palladium salt on the support, the dehydration condensation reaction is performed simultaneously with the support of the palladium salt or the palladium salt. It is preferable to carry out after loading. By immersing the carrier in a solution of palladium salt and evaporating water and the solvent in the presence of a hydrolyzate of a metal compound having a hydrolyzable functional group, the dehydration condensation reaction and the palladium salt The loading can be performed simultaneously.

  As a method for quantifying the amount of hydroxyl groups on the surface of the carrier, there is a method in which the carrier is heated and the weight loss due to the elimination of hydroxyl groups is measured. As such a method, for example, when the support is silica, the number of silanol groups can be calculated from the value of ignition loss in accordance with the measurement method of JIS K1150. In addition, there is a method in which lithium aluminum hydride is used as a quantitative reagent, hydrogen generated by reaction with hydroxyl groups on the support surface is measured using a gas burette or gas chromatograph, and the number of hydroxyl groups on the support surface is calculated.

  Moreover, in this invention, after performing process (a)-(c), it is preferable to set it as the catalyst precursor by which the palladium oxide was carry | supported at least. The catalyst precursor can also be prepared by a method in which palladium oxide is supported on a carrier after the palladium salt is supported on the carrier, but at least a part of the palladium salt is obtained by heat treatment in a state where the palladium salt is supported on the carrier. It is preferable to prepare by the method of decomposing into palladium oxide. The heat treatment temperature is preferably equal to or higher than the thermal decomposition temperature of the palladium salt. The heat treatment temperature is preferably 800 ° C. or lower, and more preferably 700 ° C. or lower. The method for raising the temperature up to the predetermined heat treatment temperature is not particularly limited, but the rate of temperature rise is preferably 1 to 10 ° C./min in order to obtain a good dispersion state of palladium atoms in the palladium-containing supported catalyst. The holding time after reaching the predetermined heat treatment temperature is not particularly limited as long as a desired amount of palladium salt is decomposed to become palladium oxide, but is preferably 1 to 12 hours.

  In the present invention, it is preferable to reduce a catalyst precursor having a palladium salt and / or palladium oxide supported on a support with a reducing agent.

  The reducing agent to be used is not particularly limited. For example, hydrazine, formaldehyde, sodium borohydride, hydrogen, formic acid, formic acid salt, ethylene, propylene, 1-butene, 2-butene, isobutylene, 1,3-butadiene, 1-butadiene, Examples include heptene, 2-heptene, 1-hexene, 2-hexene, cyclohexene, allyl alcohol, methallyl alcohol, acrolein, and methacrolein. One reducing agent can be used, or two or more reducing agents can be used in combination.

  The reduction of the palladium salt and / or palladium oxide may be performed in the gas phase or in the liquid phase. When reducing in the gas phase, it is preferable to use hydrogen as the reducing agent. Moreover, when reducing in a liquid phase, it is preferable to use hydrazine, formaldehyde, formic acid, or a salt of formic acid as a reducing agent.

  As a solvent used for the reduction in the liquid phase, water is preferable, but alcohols such as ethanol, 1-propanol, 2-propanol, n-butanol, t-butanol, etc., depending on the dispersibility of the carrier; acetone , Methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and other ketones; acetic acid, n-valeric acid, iso-valeric acid and other organic acids; heptane, hexane, cyclohexane and other hydrocarbons; Can be used. A mixed solvent of these and water can also be used.

  When the reduction is performed in the liquid phase and the reducing agent is a gas, it is preferably performed in a pressure apparatus such as an autoclave in order to increase the solubility in the solvent. At that time, the inside of the pressurizer is pressurized with a reducing agent. The pressure is preferably 0.1 to 1.0 MPa (gauge pressure; hereinafter, pressure is expressed as gauge pressure).

  Further, when the reduction is performed in the liquid phase and the reducing agent is liquid, there is no limitation on the apparatus for reducing the palladium salt and / or palladium oxide, and the reduction can be performed by adding the reducing agent to the solvent. Although the usage-amount of a reducing agent at this time is not specifically limited, It is preferable to set it as 1-100 mol with respect to 1 mol of total of palladium salt and palladium oxide.

  Although the reduction temperature and reduction time vary depending on the reducing agent and the like, 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 3 hours, and further preferably 0.5 to 2 hours.

  After the reduction, the palladium-containing supported catalyst in which palladium metal is supported on the support is separated. Although the method for separating the catalyst is not particularly limited, for example, methods such as filtration and centrifugation can be used. The separated palladium-containing supported catalyst is appropriately dried. The drying method is not particularly limited, and various methods can be used.

  The palladium-containing supported catalyst of the present invention can contain a metal component other than palladium. Examples of the metal component other than palladium include ruthenium, rhodium, silver, osmium, iridium, platinum, gold, copper, antimony, tellurium, lead, and bismuth. From the viewpoint of developing high catalytic activity, it is preferable that 50% by mass or more of the metal component contained in the palladium-containing supported catalyst is palladium metal. A palladium-containing supported catalyst containing a metal component other than palladium can be obtained by supporting a metal compound such as a corresponding metal salt or oxide on a support, and performing the reduction as necessary. The method for supporting the metal compound at that time is not particularly limited, but can be carried out in the same manner as the method for supporting the palladium salt. In addition, the metal compound can be supported before the palladium salt is supported, can be supported after the palladium salt is supported, or can be supported simultaneously with the palladium salt.

  The palladium metal loading is preferably from 0.1 to 40 mass%, more preferably from 0.5 to 30 mass%, and even more preferably from 1 to 20 mass%, based on the carrier before loading.

  The physical properties and the like of the finally obtained palladium-containing supported catalyst can be confirmed by XRD measurement, XPS measurement, TEM observation and the like.

  Next, a method for producing an α, β-unsaturated carboxylic acid by liquid phase oxidation of olefin or α, β-unsaturated aldehyde with molecular oxygen using the palladium-containing supported catalyst of the present invention will be described.

  Examples of the raw material olefin include propylene, isobutylene, 2-butene and the like. Examples of the raw α, β-unsaturated aldehyde include acrolein, methacrolein, crotonaldehyde (β-methylacrolein), and cinnamaldehyde (β-phenylacrolein). The raw material olefin or α, β-unsaturated aldehyde may contain some saturated hydrocarbons and / or lower saturated aldehydes as impurities.

  The α, β-unsaturated carboxylic acid produced is an α, β-unsaturated carboxylic acid having the same carbon skeleton as the olefin when the raw material is an olefin. When the raw material is an α, β-unsaturated aldehyde, it is an α, β-unsaturated carboxylic acid in which the aldehyde group of the α, β-unsaturated aldehyde is changed to a carboxyl group.

  The production method of the present invention is suitable for liquid phase oxidation for producing acrylic acid from propylene or acrolein, and methacrylic acid from isobutylene or methacrolein.

  As the molecular oxygen source used in the liquid phase oxidation reaction, air is economical, but pure oxygen or a mixed gas of pure oxygen and air can also be used. If necessary, air or pure oxygen is mixed with nitrogen, dioxide. A mixed gas diluted with carbon, water vapor or the like can also be used.

  The solvent used in the liquid-phase oxidation reaction is not particularly limited, but for example, water; alcohols such as tertiary butanol and cyclohexanol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; acetic acid, propionic acid, n-butyric acid, iso -Organic acids such as butyric acid, n-valeric acid and iso-valeric acid; organic acid esters such as ethyl acetate and methyl propionate; hydrocarbons such as 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 alcohol, ketones, organic acids, and organic acid esters, it is preferable to set it as a mixed solvent with water. The amount of water at that time is not particularly limited, but is preferably 2 to 70% by mass, and more preferably 5 to 50% by mass with respect to the mass of the mixed solvent. Although the solvent is desirably uniform, it 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.

  The amount of olefin or α, β-unsaturated aldehyde used as the raw material for the liquid phase oxidation reaction is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the solvent. .

  The amount of molecular oxygen used is preferably from 0.1 to 30 mol, more preferably from 0.3 to 25 mol, and more preferably from 0.5 to 20 with respect to 1 mol of the raw material olefin or α, β-unsaturated aldehyde. Mole is particularly preferred.

  The catalyst is preferably used in a state suspended in a reaction solution for liquid phase oxidation, 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. 1 to 15 parts by mass is particularly preferable.

  The reaction temperature and reaction pressure for liquid phase oxidation are appropriately selected depending on the solvent and reaction raw materials used. The reaction temperature is preferably 30 to 200 ° C, more preferably 50 to 150 ° C. The reaction pressure is preferably atmospheric pressure (0 MPa) to 10 MPa, 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)
Analysis of raw materials and products was performed using gas chromatography. The reaction rate of olefin or α, β-unsaturated aldehyde and the productivity of the α, β-unsaturated carboxylic acid produced are defined as follows.

Reaction rate of olefin or α, β-unsaturated aldehyde (%) = (B / A) × 100
Productivity of α, β-unsaturated carboxylic acid (g / gPd / h) = (C / D / E)
Here, A is the number of moles of olefin or α, β-unsaturated aldehyde supplied, B is the number of moles of reacted olefin or α, β-unsaturated aldehyde, and C is the amount of α, β-unsaturated carboxylic acid produced. Mass (g), D is the mass (g) of palladium metal in the catalyst, and E is the reaction time (h).

  In the following examples and comparative examples, a reaction for producing methacrylic acid from isobutylene is carried out. In this case, A is the number of moles of isobutylene supplied, B is the number of moles of reacted isobutylene, and C is the amount of methacrylic acid produced. The mass of acid (g).

[Example 1]
(Catalyst preparation)
An aqueous solution in which 0.22 part of telluric acid was dissolved in 15 parts of pure water was added to 4.0 parts of a palladium (II) nitrate solution (a nitric acid aqueous solution containing about 25% by mass of palladium atoms in terms of palladium metal). Further, 0.7 part of tetraethoxysilane was added, and this solution was stirred at room temperature for 1 hour to promote hydrolysis of tetraethoxysilane. Next, 10.0 parts of silica support (specific surface area: 450 m ² / g, pore volume: 0.68 cc / g, silanol group amount measured by the measuring method of JIS K1150: 6.0 mmol / g) is immersed in the above solution. Then, evaporation was performed. Thereafter, as a heat treatment, the temperature was raised from room temperature to 200 ° C. at a rate of 1.0 ° C./min, held at 200 ° C. for 3 hours, and then lowered to room temperature.

  The catalyst precursor thus obtained was added to 50.0 parts of a 37 mass% aqueous solution of formaldehyde as a reducing agent. The mixture was heated to 70 ° C., stirred and held for 2 hours, filtered and washed with 1000 parts of pure water after suction filtration. Furthermore, it was dried at 100 ° C. for 2 hours under a nitrogen flow to obtain a silica-supported palladium-containing catalyst (palladium metal support: 10.0% by mass). When the XRD measurement of the obtained catalyst was performed, it was confirmed that the metal palladium was producing | generating.

(Reaction evaluation)
A quarter of the catalyst obtained by the above method (corresponding to 0.25 part of palladium metal) was filtered and washed with a 75% by mass aqueous t-butanol solution. As a catalyst and a reaction solvent, 75 parts by mass of 75% by mass t-butanol aqueous solution was put in an autoclave, and the autoclave was sealed. Next, 2.0 parts of isobutylene was introduced, stirring (rotation speed: 1000 rpm) was started, and the temperature was raised to 90 ° 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 to initiate the reaction. When the internal pressure decreased by 0.1 MPa during the reaction (internal pressure 4.7 MPa), the operation of introducing 0.1 MPa of oxygen was repeated. The pressure immediately after introduction is 4.8 MPa. The reaction was completed 30 minutes after the start of the reaction.

  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 with a membrane filter, and the reaction solution was recovered. The collected reaction liquid and the collected gas were analyzed by gas chromatography, and the reaction rate and productivity were calculated.

[Example 2]
(Catalyst preparation)
This was carried out in the same manner as in Example 1 except that 1.4 parts of tetraethoxysilane was used.

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

[Example 3]
(Catalyst preparation)
This was carried out in the same manner as in Example 1 except that 1.8 parts of tetraethoxysilane was used.

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

[Comparative Example 1]
(Catalyst preparation)
The same procedure as in Example 1 was performed except that tetraethoxysilane was not used.

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

[Comparative Example 2]
(Catalyst preparation)
The same procedure as in Example 1 was performed except that 3.5 parts of tetraethoxysilane was used.

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

  As the above results are summarized in Table 1, it was found that according to the method of the present invention, α, β-unsaturated carboxylic acid can be produced with higher productivity.

Claims (4)

A process for producing a palladium-containing supported catalyst for producing an α, β-unsaturated carboxylic acid from an olefin or an α, β-unsaturated aldehyde comprising the steps of:
(A) supporting a palladium salt on a carrier;
(B) a step of hydrolyzing a metal compound having a hydrolyzable functional group having a mass ratio of 0.01 to 0.25 with respect to the carrier in a water-containing solution;
(C) subjecting the product obtained by the hydrolysis reaction in the step (b) to a dehydration condensation reaction in the presence of the carrier;
A process for producing a palladium-containing supported catalyst, comprising:   The method for producing a palladium-containing supported catalyst according to claim 1, wherein the step (a) and the step (c) are simultaneously performed, or the step (c) is performed after the step (a).   A palladium-containing supported catalyst obtained by the production method according to claim 1 or 2.   A method for producing an α, β-unsaturated carboxylic acid, which comprises subjecting an olefin or α, β-unsaturated aldehyde to liquid phase oxidation with molecular oxygen using the palladium-containing supported catalyst according to claim 3.