KR20170000960A

KR20170000960A - Manufacturing method of Heterogeneous Catalyst for Production of Acrylic acid and Heterogeneous Catalyst for Production of Acrylic acid using them

Info

Publication number: KR20170000960A
Application number: KR1020150090227A
Authority: KR
Inventors: 김대성; 이원재; 최용진; 이현주; 양성필
Original assignee: 주식회사 엘지화학; 한국과학기술원
Priority date: 2015-06-25
Filing date: 2015-06-25
Publication date: 2017-01-04
Also published as: KR102015625B1

Abstract

The present invention relates to a process for producing a heterogeneous catalyst for the production of acrylic acid and a heterogeneous catalyst for the production of acrylic acid using the process.

Description

TECHNICAL FIELD The present invention relates to a heterogeneous catalyst for the production of acrylic acid and a heterogeneous catalyst for the production of acrylic acid by using the heterogeneous catalyst,

Acrylic acid is an organic compound containing a carboxylic acid and a vinyl group, and belongs to an unsaturated carboxylic acid. It is a main raw material of a super absorbent polymer (SAP) which is a synthetic polymer substance capable of absorbing moisture of about 1,000 times its own weight.

The highly water-absorbent resin has been put to practical use as a sanitary article and is now being used as a material for seedling seeds, soil repair agent for gardening, civil engineering, and construction index material. Compared with other absorbers, superabsorbent resins with superior absorption capacity have wider application and increased market value. Acrylic acid is also a key raw material for acrylic esters used in various applications such as acrylic fibers, paints, adhesives, and coatings. Conventional acrylic acid is generally produced from fossil fuel-derived propylene through acrolein. Therefore, there has been a need to produce acrylic acid from non-fossil fuels. Recently, WO 2008/092115 A1 discloses a method for producing allyl alcohol from glycerol, which is a biomass-derived material, at a high yield.

Glycerol is produced as a by-product in the process of producing biodiesel from vegetable oil and can increase the production value of biodiesel if glycerol can be effectively used. Therefore, if acrylic acid can be produced from allyl alcohol, the production value of biodiesel can be increased while reducing the dependence of fossil fuel.

WO 2008/092115

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art, and it is an object of the present invention to provide a process for producing a heterogeneous catalyst used in a process for producing acrylic acid from allyl alcohol. The present invention also aims to improve the reproducibility and durability of the heterogeneous catalyst used in the acrylic acid production process.

In order to achieve the above object, the present invention provides a method for producing acrylic acid, which comprises dissolving a gold precursor in distilled water and adjusting pH to 8 to 12 by adding a basic compound, A method for producing a heterogeneous catalyst is provided. The gold spheres may include any one or more selected from the group consisting of HAuCl ₄ , HAuCl ₄ .3H ₂ O, HAuCl ₄ .4H ₂ O, AuCl ₃ and AuCl. According to a preferred embodiment of the present invention, the metal oxide may further be calcined at 100 to 700 ° C for 10 to 24 hours. The frequency of the ultrasonic waves may be 10 kHz or more and 300 kHz or less.

Another aspect of the present invention is a method for producing a non-homogeneous catalyst, comprising the steps of: a) introducing a heterogeneous catalyst of the present invention into a mixed solution of a basic solution and allyl alcohol; b) introducing an oxygen-containing gas into the reactor containing the mixed solution of step a), reacting in the state where the internal oxygen partial pressure is 1 to 50 bar based on the absolute pressure and the reactor internal temperature is 30 to 100 ° C Preparing a liquid reaction product comprising acrylic acid; And c) separating the acrylic acid from the liquid reaction product prepared in the step (a).

The method for producing a heterogeneous catalyst for producing acrylic acid of the present invention can improve the durability as well as the reproducibility of the heterogeneous catalyst for producing acrylic acid. Therefore, in the case of producing acrylic acid from allyl alcohol using this, it is possible to improve the productivity of acrylic acid production by helping commercial scale production. In addition, the method is eco-friendly because it is used in a method for producing acrylic acid from allyl alcohol produced from glycerol which is a biomass-derived material. Further, it is possible to effectively utilize glycerol, which is a by-product of biodiesel, to increase the efficiency of biodiesel and to provide an effective effect to produce acrylic acid efficiently from glycerol.

1 is a transmission electron micrograph of the heterogeneous catalyst prepared in Example 1-1.
2 is a transmission electron micrograph of the heterogeneous catalyst prepared in Example 1-2.
3 is a transmission electron micrograph of the heterogeneous catalyst prepared in Example 1-3.
4 is a transmission electron micrograph of the heterogeneous catalyst prepared in Comparative Example 1-2.

Hereinafter, the present invention will be described in detail. The following detailed description is merely an example of the present invention, and therefore, the present invention is not limited thereto.

The term " heterogeneous catalyst " used in the present invention means that the phase of the catalyst and the catalyst are different from each other.

The present invention relates to a method for producing acrylic acid as a main product in a high yield through a liquid phase reaction using a heterogeneous catalyst prepared under specific synthesis conditions of the present invention. That is, the present invention relates to a method for preparing a heterogeneous catalyst for the production of acrylic acid, which comprises dissolving a gold precursor in distilled water and adjusting a pH to 8 to 12 by adding a basic compound, and then introducing a metal oxide and performing ultrasonic treatment .

Hereinafter, the present invention will be described in detail.

First, the gold precursor will be described.

In the present invention, the gold precursor provides gold contained in the heterogeneous catalyst, The gold is a catalytically active site where the reactant, allyl alcohol, is adsorbed and a catalytic reaction takes place. The gold precursor may be any one that is generally usable. According to one preferred embodiment of the present invention, HAuCl _4, HAuCl ₄ · may include _{3H 2 O, HAuCl 4 · 4H} 2 O, 1 or more selected from the group consisting of AuCl ₃ and AuCl. most Preferably it may be HAuCl ₄ · 3H ₂ O. In addition, the gold spheres may include 0.02 to 0.06 parts by weight, preferably 0.024 to 0.048 parts by weight, based on 100 parts by weight of the distilled water. If the gold spheres are less than 0.02 parts by weight, gold may not be deposited due to low concentration. If it exceeds 0.06 part by weight, there may be a problem that gold particles are excessively synthesized to a large extent, and therefore, the above range is preferable.

The following basic compounds will be described.

The basic compound serves to convert the ligand of gold from Cl to OH.

Through this, the gold in the oxidized state is appropriately reduced to the gold in the metal state under the catalyst synthesis conditions, and the gold in the oxidized state and the gold in the metal state have an appropriate ratio (about 30% of the oxidation state and about 70% of the metal state) It is a decisive cause of high yield in production.

According to a preferred embodiment of the present invention, it may include at least one selected from the group consisting of sodium hydroxide, lithium hydroxide, potassium hydroxide and calcium hydroxide. Most preferably sodium hydroxide. The basic compound may include 4 to 15 parts by weight, preferably 5 to 8 parts by weight, based on 100 parts by weight of the distilled water. If the amount of the basic compound is less than 4 parts by weight, there is a problem that the catalytic reaction does not normally occur. If it exceeds 15 parts by weight, the catalyst may be damaged. Therefore, the above range is preferable.

The metal oxide serves as a support for the heterogeneous catalyst of the present invention.

According to a preferred embodiment of the present invention, the metal oxide is selected from the group consisting of activated carbon, titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), zinc oxide (ZnO ₂ ) zirconium (ZrO _2), manganese oxide (MnO _2), iron oxide (Fe ₂ O _3), vanadium oxide (V ₂ O _5), tin oxide (SnO _2), tungsten oxide (WO ₃₎ and cerium oxide (CeO ₂₎ , And the like. Most preferably, the metal oxide may be a composite oxide containing cerium oxide (CeO ₂₎ or cerium oxide. The metal oxide may include 95 to 99.9 parts by weight, preferably 97 to 98 parts by weight, based on 100 parts by weight of the catalyst. If the amount of the metal oxide is less than 95 parts by weight, expensive gold may be excessively used. If the amount of the metal oxide is more than 99.9 parts by weight, the amount of gold used may be insufficient, The above range is preferable.

According to a preferred embodiment of the present invention, the metal oxide is calcined at 100 to 700 ° C., preferably 300 to 500 ° C., for 10 to 24 hours, preferably 20 to 24 hours, Can be used. By further performing the step of calcining the metal oxide, the metal oxide is sufficiently oxidized.

By calcining, the absence of oxygen vacancies on the surface of the metal oxide has the effect of further stabilizing the relatively active gold phase, thereby greatly improving the recyclability of the gold / metal oxide catalyst. If the calcining temperature is less than 100 deg. C, there may be a problem that the metal oxide surface is not sufficiently oxidized and oxygen vacancy still exists. On the other hand, if it exceeds 700 ° C, the crystal structure of the metal oxide may be damaged, so the above range is preferable. If the calcination time is less than 10 hours, the surface of the metal oxide may not be sufficiently oxidized, and oxygen vacancy may still exist. If it exceeds 24 hours, the crystal structure of the metal oxide may be damaged, so that the above range is preferable.

Then, a step of performing ultrasonic treatment on the solution containing the distilled water, the gold precursor, the basic compound and the metal oxide is carried out.

The polar ultrasonic wave may be performed at a frequency of 10 kHz or more, 300 kHz or less, preferably 20 kHz or more, and 60 kHz or less. If the ultrasonic wave is less than 10 kHz, there is a problem that the cavitation strength is strong and the particles are damaged. If the frequency is higher than 300 kHz, the effect of ultrasonic wave treatment may be weakened and the reproducibility of synthesis may be deteriorated. The ultrasonic treatment time may be 3 to 20 minutes, preferably 5 to 10 minutes, but is not limited thereto. If the ultrasonic wave is less than 3 minutes, there is a problem that the dispersion of the catalyst is insufficient, and if it exceeds 20 minutes, the structure of the catalyst may be damaged.

Another aspect of the present invention is The present invention provides a heterogeneous catalyst for the production of acrylic acid prepared by the process of the present invention.

Specifically, in the heterogeneous catalyst for producing acrylic acid, gold is supported on the surface of the metal oxide support. According to a preferred embodiment of the present invention, the gold may be included in an amount of 5 wt% or less based on the total dry weight of the metal oxide support. This has the advantage of maximizing the reactivity while minimizing the use of precious metal gold. Preferably 2 to 3% by weight, and if it is more than 5% by weight, the size of the gold particles is increased, and the reaction activity is greatly reduced.

And the gold may be a particle size of 10 nm or less, preferably 5 nm or less. When the size of the gold particles satisfies the above range, the effect of reactivity and selectivity is excellent. In addition, as the size of gold particles is smaller, the yield of acrylic acid and 3-hydroxypropionic acid (3-HPA), which are the products, is increased. Particularly, when the size of the gold particles is 2 nm or less, the yield of acrylic acid as the main product is more preferably 50% or more

Another aspect of the present invention is a method for producing a heterogeneous catalyst, comprising the steps of: a) introducing the heterogeneous catalyst of the present invention into a mixed solution of a basic solution and allyl alcohol; b) introducing an oxygen-containing gas into the reactor containing the mixed solution of step a), reacting in the state where the internal oxygen partial pressure is 1 to 50 bar based on the absolute pressure and the reactor internal temperature is 30 to 100 ° C Preparing a liquid reaction product comprising acrylic acid; And c) separating the acrylic acid from the liquid reaction product prepared in the step (a).

First, the step a) will be described.

In the method for producing acrylic acid according to the present invention, the allyl alcohol can be used without any particular limitation as long as it can be used in the production of acrylic acid. Preferably, allyl alcohol having a purity of 60 to 99.9% can be used. More specifically, acrylic acid may be produced from allyl alcohol using the heterogeneous catalyst of the present invention, and the basic solution may be prepared by mixing a basic compound containing an alkali metal or an alkaline earth metal with water. More specifically, the basic compound may include at least one selected from the group consisting of sodium hydroxide, lithium hydroxide, potassium hydroxide, and calcium hydroxide.

The basic compound contained in the basic solution is preferably added in an amount of 1 to 10 molar equivalents based on 1 mol of the allyl alcohol, more preferably 3 to 6 molar equivalents. Depending on the amount of the basic compound, the conversion of allyl alcohol and the yield and selectivity of acrylic acid, 3-hydroxypropionic acid (3-HPA), glyceric acid are affected. In addition, acid products in the product, including acrylic acid and 3-hydroxypropionic acid (3-HPA), can be produced in salt form by the addition of basic compounds. Then, the heterogeneous catalyst provided in the present invention is introduced into the mixed solution.

The following step b) will be described.

In this step, a liquid reaction product containing acrylic acid is prepared.

Specifically, after the reactor including the mixed solution is adjusted to a vacuum state, a gas containing oxygen is introduced to pressurize the internal oxygen partial pressure by 1 to 50 bar on the basis of the absolute pressure, The reaction is carried out at 100 ° C for 1 to 30 hours.

The gas introduced into the reactor may contain 10 vol% or more of oxygen, preferably 60 to 100 vol%, and more preferably 90 to 100 vol%. If the oxygen content is less than 60% by volume, there is a problem that the oxidation reaction rate is very slow. In addition, the pressure of the oxygen partial pressure in the reactor can preferably be maintained at 1 to 50 bar. If the pressure is below 1 bar, the oxidation reaction will not occur. If the pressure exceeds 50 bar, the additional effect due to the pressure increase will be insignificant.

The temperature in the reactor is adjusted to 30 to 100 ° C, preferably 50 to 80 ° C. If the internal temperature in the reactor is less than 30 ° C, the oxidation reaction rate becomes very slow and the conversion of allyl alcohol is greatly reduced. When the temperature exceeds 100 ° C, the side reaction is greatly increased due to the temperature increase, Occurs.

Meanwhile, the reactor used in the step b) is applicable to all known reactors such as a batch reactor, a continuous stirred tank reactor (CSTR), a plug flow reactor (PFR) and a fluidized bed reactor. The resulting liquid reaction product may include at least one member selected from the group consisting of acrylic acid, 3-hydroxypropionic acid (3-HPA), and glyceric acid.

In the step c), acrylic acid is separated from the liquid reaction product, and acidification, ion exchange, extraction, crystallization and distillation may be used.

In conclusion, in the method of producing acrylic acid from allyl alcohol, when the heterogeneous catalyst of the present invention is used, the yield of acryl is 30% or more, and more preferably 50% or more.

In addition, the heterogeneous catalyst produced by the heterogeneous catalyst production method of the present invention is excellent in the reproducibility of synthesis and durability.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the embodiments of the present invention described below are illustrative only and the scope of the present invention is not limited to these embodiments. The scope of the present invention is indicated in the claims, and moreover, includes all changes within the meaning and range of equivalency of the claims. In the following Examples and Comparative Examples, "%" and "part" representing the content are based on weight unless otherwise specified.

<< Heterogeneous system Catalyst manufacturing >>

Example 1-1

12 mg of HAuCl ₄ .3H ₂ O was dissolved in 50 ml of distilled water, and the pH of the solution was adjusted to 10 by using sodium hydroxide solution. Thereafter, 200 mg of cerium oxide was dispersed in the solution and subjected to ultrasonication treatment at 20 kHz for 10 minutes. Thereafter, the solution was maintained at 70 DEG C for 1 hour to obtain a catalyst. This experiment was repeated three times in total to obtain three catalysts. The average particle size of the gold in the prepared catalyst is 1.5 nm.

Example 1-2

1 g of cerium oxide was placed in an alumina boat and calcined in a tube furnace at 400 DEG C for 8 hours to obtain cerium oxide. A catalyst was obtained in the same manner as in Example 1 except that the above-mentioned cerium oxide was used. This experiment was repeated three times in total to obtain three catalysts. The average particle size of the gold in the prepared catalyst is 4 nm.

Example 1-3

12 mg of HAuCl ₄ .3H ₂ O was dissolved in 50 ml of distilled water, and the pH of the solution was adjusted to 10 by using sodium hydroxide solution. Thereafter, 200 g of cerium oxide was dispersed in the solution and subjected to ultrasonication treatment at 20 kHz for 10 minutes. Thereafter, the solution was maintained at 70 DEG C for 9 hours to obtain a catalyst. This experiment was repeated three times in total to obtain three catalysts. The average particle size of the gold in the prepared catalyst is 4 nm.

Comparative Example 1-1

A catalyst was obtained in the same manner as in Example 1-1 except that the ultrasound treatment step was not performed. This experiment was repeated four times in total to obtain a total of four catalysts. The average particle size of the gold in the prepared catalyst is 4 nm.

Comparative Example 1-2

12 mg of HAuCl ₄ .3H ₂ O was dissolved in 50 ml of distilled water and a basic solution having a pH of 10 was prepared using sodium hydroxide solution. 200 mg of cerium oxide was dissolved in 5 ml of distilled water and ultrasonic treatment was performed at 20 kHz for 10 minutes to prepare a metal oxide solution. The metal oxide solution was added to the basic solution, and the solution was maintained at 70 ° C for 1 hour to obtain a catalyst. This experiment was repeated twice in total to obtain two catalysts in total. The average particle size of the gold in the prepared catalyst is 4 nm.

Experimental Example One

The heterogeneous catalysts prepared in Examples 1-1, 1-2 and 1-3 and 1-2 were observed with a transmission electron microscope (TF-30 300 KV, Tecnai).

Fig. 1 is a photograph of the surface of the catalyst prepared in Example 1-1, Fig. 2 is Example 1-2, Fig. 3 is Example 1-3, and Fig. 4 is Comparative Example 1-2.

<< Heterogeneous system Check the reproducibility of catalyst synthesis >>

Example 2-1.

The three catalysts prepared in Example 1-1 were subjected to a total of three times in the following manner.

35 mg of the catalyst prepared in Example 1-1 was added to a mixed solution of 17.24 ml of distilled water, 2.07 g of sodium hydroxide and 1.17 ml of allyl alcohol, and the solution was placed in a 50 ml glass reactor. After the glass reactor was adjusted to a vacuum, high purity oxygen gas was charged to 3 bar and maintained at 3 bar during the reaction. The glass reactor was then reacted at 50 < 0 > C for 12 hours. A liquid reaction product obtained by the above method was obtained.

Comparative Example 2-1

The four catalysts prepared in Comparative Example 1-1 were each subjected to a total of four times by the following method.

35 mg of the catalyst prepared in Comparative Example 1-1 was added to a mixed solution of 17.24 ml of distilled water, 2.07 g of sodium hydroxide and 1.17 ml of allyl alcohol, and the solution was placed in a 50 ml glass reactor. After the glass reactor was adjusted to a vacuum, high purity oxygen gas was charged to 3 bar and maintained at 3 bar during the reaction. The glass reactor was then reacted at 50 < 0 > C for 12 hours. A liquid reaction product obtained by the above method was obtained.

Comparative Example 2-2

The two catalysts prepared in Comparative Example 1-2 were each subjected to a total of two times by the following method.

35 mg of the catalyst prepared in Comparative Example 1-2 was added to a mixed solution of 17.24 ml of distilled water, 2.07 g of sodium hydroxide and 1.17 ml of allyl alcohol, and the solution was placed in a 50 ml volume glass reactor. After the glass reactor was adjusted to a vacuum, high purity oxygen gas was charged to 3 bar and maintained at 3 bar during the reaction. The glass reactor was then reacted at 50 < 0 > C for 12 hours. A liquid reaction product obtained by the above method was obtained.

Experimental Example 2

The liquid reaction products prepared in Example 2-1, Comparative Example 2-1 and Comparative Example 2-2 were subjected to qualitative and quantitative analysis using liquid chromatography (YL9100 HPLC, Young Lin Instrument Co.) Respectively. And the yields of acrylic acid, 3-hydroxypropionic acid and glyceral acid were calculated. Equations (1) to (3) were used to calculate the allyl alcohol conversion and acrylic acid yield and acrylic acid selectivity. The values are shown in Table 1.

[Equation 1]

Allyl alcohol conversion (conversion,%) = 100 x (mole of allyl alcohol before reaction - mole of allyl alcohol after reaction) / (mole of allyl alcohol before reaction)

&Quot; (2) "

Yield of acrylic acid (yield,%) = 100 x (molar amount of acrylic acid produced) / (molar amount of allyl alcohol before reaction)

&Quot; (3) "

Acrylic acid selectivity (%) = 100 x (acrylic acid yield) / (allyl alcohol conversion)

division catalyst Ultrasonication treatment Conversion (%) Yield (%) Acrylic acid 3-HPA Glyceric acid Example 2-1 One O 100 50.7 29.6 2.8 2 O 100 50.4 29.6 2.6 3 O 100 51.1 30.1 2.9 Comparative Example 2-1 One X 100 46.6 26.5 2.6 2 X 100 43.8 26.1 3.3 3 X 100 44.1 25.3 3.1 4 X 100 42.8 26.5 4.8 Comparative Example 2-2 One CeO ₂ Solution only polar ultrasonic 100 43.3 35.4 2.8 2 100 44.2 35.6 3.0

Specifically, Table 1 shows that the yield of acrylic acid and 3-hydroxypropionic acid is uniform and higher than that of Comparative Example 2-1 and Comparative Example 2-2, as a whole.

<< Heterogeneous system Durability test of catalyst >>

Example 3-1

The one catalyst prepared in Example 1-1 was repeated four times for the reuse three times.

Example 3-2

The one catalyst prepared in Example 1-2 was repeated four times for the reuse three times.

35 mg of the catalyst prepared in Example 1-2 was added to a mixed solution of 17.24 ml of distilled water, 2.07 g of sodium hydroxide and 1.17 ml of allyl alcohol, and the solution was placed in a 50 ml volume glass reactor. After the glass reactor was adjusted to a vacuum, high purity oxygen gas was charged to 3 bar and maintained at 3 bar during the reaction. The glass reactor was then reacted at 50 < 0 > C for 12 hours. A liquid reaction product obtained by the above method was obtained.

Experimental Example 3

The liquid reaction products prepared in Examples 3-1 and 3-2 were subjected to qualitative and quantitative analysis using liquid chromatography (YL9100 HPLC, Young Lin Instrument Co.). And the yields of acrylic acid, 3-hydroxypropionic acid and glyceral acid were calculated. The above equations (1) to (3) were used to calculate the allyl alcohol conversion, acrylic acid yield and acrylic acid selectivity. The values are shown in Table 2.

Catalyst Conversion (%) Yield (%) Acrylic acid 3-HPA Glyceric acid Example 3-1 Early 100 42.7 29.5 1.6 One reuse 100 38.4 31.4 1.6 Reuse 2 times 100 39.1 35.6 2.9 Reuse 3 times 100 27.1 42.2 3.2 Example 3-2 Early 100 42.8 30.3 2.9 One reuse 100 42.6 30.6 3.3 Reuse 2 times 100 41.0 31.3 3.7 Reuse 3 times 100 38.0 34.9 3.8

Table 2 shows that the gold particles in the catalysts prepared in Examples 1-1 and 1-2 are similar in size, and the yield of the liquid reaction product of Example 3-2 and the conversion rate of allyl alcohol Is superior to Example 3-1. Therefore, the catalyst prepared in Example 1-2 has higher durability than that of Example 1-1.

Claims

Dissolving a gold precursor in distilled water, adding a basic compound to adjust the pH to 8 to 12, introducing a metal oxide, and conducting ultrasound treatment to obtain a heterogeneous catalyst.

The method according to claim 1,
The metal oxide
And calcining the catalyst at 100 to 700 ° C for 10 to 24 hours.

The method according to claim 1,
Wherein the gold precursor comprises at least one selected from the group consisting of HAuCl ₄ , HAuCl ₄ .3H ₂ O, HAuCl ₄ .4H ₂ O, AuCl ₃ and AuCl.

The method according to claim 1,
Wherein the basic compound comprises at least one selected from the group consisting of sodium hydroxide, lithium hydroxide, potassium hydroxide, and calcium hydroxide.

The method according to claim 1,
The metal oxide may be at least one selected from the group consisting of activated carbon, titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), zinc oxide (ZnO ₂ ), zirconium oxide (ZrO ₂ ) _2), iron oxide (Fe ₂ O _3), vanadium oxide (V ₂ O _5), tin oxide (SnO _2), tungsten oxide (WO ₃₎ and at least one selected from the group consisting of cerium oxide (CeO ₂₎ Based on the total weight of the heterogeneous catalyst.

The method of claim 5,
Wherein the metal oxide is a composite oxide containing cerium oxide (CeO ₂ ) or cerium oxide.

The method according to claim 1,
Wherein the frequency of the ultrasonic waves is 10 kHz or more and 300 kHz or less.

A heterogeneous catalyst for the production of acrylic acid produced by the process of claim 1.

The method of claim 8,
Wherein the heterogeneous catalyst for producing acrylic acid is characterized in that gold is supported on the surface of the metal oxide support.

The method of claim 8,
Wherein the gold is contained in an amount of 5 wt% or less based on the total dry weight of the metal oxide support.

The method of claim 8,
Wherein the gold has a particle size of 10 nm or less.

a) introducing the heterogeneous catalyst of claim 8 into a mixed solution of a basic solution and allyl alcohol;
b) introducing an oxygen-containing gas into the reactor containing the mixed solution of step a), reacting in the state where the internal oxygen partial pressure is 1 to 50 bar based on the absolute pressure and the reactor internal temperature is 30 to 100 ° C Preparing a liquid reaction product comprising acrylic acid; And
and c) separating the acrylic acid from the liquid reaction product.