WO2023113539A1 - Method for producing carbon dioxide-derived formic acid using dual catalyst - Google Patents

Abstract

The present invention pertains to a method for producing carbon dioxide-derived formic acid using a dual catalyst, wherein the yield of formic acid produced through carbon dioxide hydrogenation under base-free conditions is improved by adding a Keplerate-type metal-containing nanocluster or a heterogeneous catalyst thereof as a hydration catalyst to a base-free carbon dioxide hydrogenation reaction using a conventional hydrogenation catalyst, and thereby increasing, by means of the hydration catalyst, the content in the reaction solution of bicarbonate ions reacting with the hydrogenation catalyst through a hydration reaction of carbon dioxide.

Description

Carbon dioxide-derived formic acid production method using a dual catalyst

The present invention relates to a method for producing formic acid derived from carbon dioxide using a dual catalyst, and more particularly, in producing formic acid through hydrogenation of carbon dioxide in an axiolytic condition, a hydrogenation catalyst and a hydration catalyst are used together to obtain the hydration catalyst. It relates to a method for producing formic acid derived from carbon dioxide using a dual catalyst capable of improving the yield of formic acid by increasing the content of bicarbonate ions in a reaction solution reacted with the hydrogenation catalyst through a hydration reaction of carbon dioxide by the.

Due to the rapid increase in anthropogenic carbon dioxide emissions due to the use of fossil fuels in modern society, the global carbon dioxide level has risen to 415 ppm, which is causing global warming and abnormal climate patterns. However, such carbon dioxide has recently emerged as a carbon source for value-added organic products produced through catalytic/chemical transformation. For example, carbon dioxide can be converted to formaldehyde, formic acid, methane, methanol, etc., of which hydrogenation of carbon dioxide to formic acid has attracted particular attention due to its atomic efficiency and availability as a chemical feedstock and fuel.

As described above, when converting carbon dioxide into formic acid, converting it in a gaseous state has a large thermodynamic energy loss due to an adverse change in entropy, so carbon dioxide is dissolved in a solvent and then converted into formic acid using a homogeneous or heterogeneous catalyst. However, due to the low solubility of carbon dioxide in the reaction solution and the limitation of carbon dioxide activation, the production of formic acid by hydrogenating carbon dioxide under anhydrous conditions has a problem of very low conversion efficiency.

In addition, in order to further lower the Gibbs free energy, the formic acid conversion reaction through hydrogenation of carbon dioxide in a solvent phase is generally performed in the presence of basic additives such as amines, hydroxides, bicarbonates, and carbonates. During the reaction, carbon dioxide is converted into dissolved inorganic carbon (DIC) compounds such as carbonic acid (H ₂ CO ₃ ), bicarbonate (HCO ₃ ^- ), carbonate (CO ₃ ^2- ), depending on the pH of the water, and formate through an additional acidification process. Formic acid was prepared from carbon dioxide by converting to formic acid.

As described above, since the method for producing formic acid derived from carbon dioxide in the presence of a basic additive requires an additional acidification process, a method for directly converting carbon dioxide into formic acid under a non-basic condition has been researched and developed.

In a heterogeneous catalyst system, Pd-based nanocatalysts are capable of base-free carbon dioxide hydrogenation due to their excellent ability to adsorb and dissociate hydrogen, and recently, it has been reported that PdM (M = Ni or Ag) alloys can increase the yield of formic acid under non-base conditions. Confirmed. However, despite these efforts, carbon dioxide hydrogenation under anhydrous conditions still suffers from low carbon dioxide conversion (<2%). The reasons for this inefficiency are not only the thermodynamic properties of the reaction, but also the difficulty of activating CO ₂ and the extremely low solubility of carbon dioxide in neutral solutions compared to basic solutions.

In accordance with the circumstances described above, the present invention intends to propose a method for producing formic acid by using a hydrogenation catalyst after increasing the solubility of carbon dioxide by using a hydration catalyst and increasing the concentration of bicarbonate ions in a solution.

On the other hand, carbonic anhydrase (CA) in living organisms hydrates carbon dioxide into bicarbonate ions and protons with a high reaction rate (k = ~10 ⁶ s ^-1 ) at the Zn(His) ₃ (H ₂ O) center. catalyze that Carbonic anhydrase as described above is limited in its application under severe pH and high temperature industrial catalyst conditions. The present invention, based on the understanding of the structural catalytic mechanism of carbonic anhydrase, designs artificial structural analogues and transition metal complexes that can withstand the harsh reaction conditions required for carbon dioxide hydration, and uses them as carbon dioxide hydration catalysts in basic conditions. A new manufacturing method capable of producing formic acid from carbon dioxide is proposed.

As a prior art for hydrogenation of carbon dioxide in the technical field of the present invention, US Patent Publication 2016-0137573 A1 and Korean Patent Publication 10-2020-0057644 A disclose that carbon dioxide is exposed to an amine compound to convert it into bicarbonate through hydrogenation. A method for increasing the yield of formic acid is disclosed, but the amine compound is a kind of base and does not include technology for directly producing formic acid using a hydration and hydrogenation catalyst under a non-basic condition. In addition, PCT application patent WO2016- 185292 A1 describes the use of a Mo ₁₃₂ -based catalyst in the process of producing formic acid from carbon dioxide, but the catalyst (Mo ₁₃₂ *) is not a carbon dioxide hydration catalyst, but is believed to be used as a catalyst that oxidizes water after excitation. As in the present invention, a technique for improving the yield of formic acid through hydrogenation after hydration of carbon dioxide using a Mo ₁₃₂ catalyst has not been known.

The present invention was created to solve the above problems, and in the production of formic acid through hydrogenation of carbon dioxide in a non-basic condition, a hydrogenation catalyst and a hydration catalyst are used together, and the hydration reaction of carbon dioxide by the hydration catalyst It is an object of the present invention to provide a method for producing formic acid derived from carbon dioxide using a dual catalyst capable of increasing the yield of formic acid by increasing the content of bicarbonate ions in the reaction solution reacted with the hydrogenation catalyst through the.

In addition, the present invention is a carbon dioxide hydration catalyst as described above, using a carbonic anhydrase (CA)-type metal-containing nanocluster or a heterogenized catalyst that mimics carbonic anhydrase (CA). The purpose is to provide a method for producing formic acid derived from carbon dioxide using a catalyst.

In addition, the present invention is a carbon dioxide-derived formic acid production method using a dual catalyst capable of improving the yield of formic acid by using Mo ₁₃₂ clusters as the Keplerate-type metal-containing nanoclusters among the carbon dioxide hydration catalysts. Its purpose is to provide

In addition, the present invention is a heterogeneous catalyst of the Keplerate-type metal-containing nanoclusters among the above carbon dioxide hydration catalysts, and the Mo ₁₃₂ cluster is a metal organic framework (MOF) or a zeolite imidazolate framework (ZIF) The purpose is to provide a method for producing formic acid derived from carbon dioxide using a dual catalyst that can further improve the yield of formic acid by using a composite catalyst encapsulated in ).

A method for producing formic acid derived from carbon dioxide using a dual catalyst according to an embodiment of the present invention includes a hydration catalyst that converts carbon dioxide into bicarbonate ions through a hydration reaction and a hydrogenation catalyst that converts bicarbonate ions into formic acid through a hydrogenation reaction. providing a catalyst; and reacting carbon dioxide, hydrogen, and water under the dual catalyst to produce bicarbonate ions by reacting carbon dioxide and water by the hydration catalyst, and producing formic acid by reacting the bicarbonate ions and hydrogen by the hydrogenation catalyst. The hydration catalyst is a Keplerate-type metal-containing nanocluster or a heterogeneous catalyst thereof, and the hydrogenation catalyst is an active metal in the catalyst composite, ruthenium (Ru), iridium (Ir), rhodium ( One of Rh), platinum (Pt), palladium (Pd), silver (Ag), gold (Au), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and zinc (Zn) It is characterized in that the metal or composite metal containing the above is a catalyst supported on a support.

In addition, as an embodiment of the present invention, the Keplerate-type metal-containing nanocluster is a Keplerate-type Mo ₁₃₂ cluster.

In addition, as an embodiment of the present invention, the heterogeneous catalyst is a composite catalyst in which Mo ₁₃₂ clusters of Keplerate type are encapsulated in a metal organic framework (MOF) or a zeolite imidazolate framework (ZIF). characterized by

In addition, as an embodiment of the present invention, the heterogeneous catalyst is a composite catalyst ( _{Mo 132 @} MIL- 100 (Fe)).

In addition, as an embodiment of the present invention, the support is characterized in that at least one selected from a carbonaceous material, a molecular sieve, a ceramic material, and a metal oxide.

In addition, as an embodiment of the present invention, it is characterized in that the pressure of carbon dioxide in the mixed solution of carbon dioxide, hydrogen, water and the dual catalyst is 5 to 100 bar.

In addition, as an embodiment of the present invention, the ratio of carbon dioxide and hydrogen in the mixed solution of carbon dioxide, hydrogen, water, and the dual catalyst is the ratio of moles converted to carbon dioxide and hydrogen, respectively, and the mole ratio of carbon dioxide / hydrogen is 0.2 to 5 It is characterized by being

In addition, as an embodiment of the present invention, the hydration catalyst is added in an amount of 0.001 to 10 parts by weight based on 100 parts by weight of the water.

In addition, as an embodiment of the present invention, the hydrogenation catalyst is characterized in that the addition of 0.01 to 5 parts by weight based on 100 parts by weight of the water.

In addition, as an embodiment of the present invention, in the method for producing formic acid derived from carbon dioxide using the dual catalyst, as reaction conditions, the reaction temperature is 5 to 100 ° C, the pressure is 10 to 200 bar, and the reaction time is 1 to 1000 characterized by time.

The present invention, in producing formic acid through hydrogenation of carbon dioxide under anhydrous conditions, uses a keplerate-type metal-containing nanocluster or a heterogeneous catalyst thereof together with a hydrogenation catalyst as a carbon dioxide hydration catalyst, Due to the carbon dioxide hydration ability derived from ligand exchange, the yield of formic acid can be improved by increasing the content of the bicarbonate ion reacted with the hydrogenation catalyst in the reaction solution.

In addition, the carbon dioxide hydration catalyst, Keplerate-type metal-containing nanoclusters or heterogeneous catalysts thereof according to the present invention can be recovered and recycled without loss of catalytic activity or structural damage, and thus can be used for continuous reactions. .

Hereinafter, in the description, FA is formic acid, and HIFA is an abbreviation of hydration induced formic acid, and corresponds to increased formic acid due to a hydration catalyst.

1 is a view showing the structure of a Mo ₁₃₂ cluster hydration catalyst used in a method for producing formic acid derived from carbon dioxide using a dual catalyst according to an embodiment of the present invention.

2 is a view showing the structure of a Mo ₁₃₂ @MIL-100(Fe) hydration catalyst used in the method for producing formic acid derived from carbon dioxide using a dual catalyst according to an embodiment of the present invention.

3 is a view showing the synthesis step of the Mo ₁₃₂ cluster catalyst.

4 is a SEM image of (a) MIL-100 (Fe), (b) 3% Mo ₁₃₂ @MIL-100 (Fe), (c) 6% Mo ₁₃₂ @MIL-100 (Fe) and (d) 3 It is an EDS map image of % Mo ₁₃₂ @MIL-100 (Fe).

5 shows the particle size distribution of (a) MIL-100 (Fe), (b) 3% Mo ₁₃₂ @MIL-100, and (c) 6% Mo ₁₃₂ @MIL-100 (Fe).

6 shows (a) PXRD pattern, (b) TGA profile, (c) N2 adsorption-desorption isotherm, (d) Mo ₁₃₂ cluster (black), MIL-100 (Fe) (red), 3% Mo ₁₃₂ @MIL Pore size distributions of -100(Fe) (blue) and 6% Mo ₁₃₂ @MIL-100(Fe) (pink) are shown.

7 shows the results of XPS survey spectra of Mo ₁₃₂ clusters and 3% and 6% Mo ₁₃₂ @MIL-100 (Fe).

8 shows (a) high resolution XPS spectrum of Mo ₁₃₂ cluster and Mo 3d region in 3% Mo ₁₃₂ @MIL-100 (Fe), (b) and (c) are (i) Mo ₁₃₂ cluster, (ii) MIL -100 (Fe), (iii) 3% Mo ₁₃₂ @MIL-100 (Fe), (iv) 6% Mo ₁₃₂ @MIL-100 (Fe) shows the Raman spectrum and FTIR spectrum.

9 (a) to (c) are (a) 0.5 g Pd / C, (b, c) FA and HIFA yields when reacted for 1 hour using 0.5 g Pd / C and 0.5 μmol Mo ₁₃₂ cluster and TON, and (d) shows an Arrhenius plot for the production of FA and HIFA at 20 to 60 °C using 0.5 g Pd/C or 0.5 g Pd/C and 0.5 μmol Mo ₁₃₂ clusters .

10 shows the FA yield when reacted for 1 hour using Pd/C or Pd/C and Mo ₁₃₂ clusters at various temperature ranges.

Figure 11 (a), (b) is the FA production rate when reacted for 1 hour using Pd / C, (c) is the HIFA production rate when reacted for 1 hour using Mo ₁₃₂ cluster .

12 (a) is the ¹ H NMR spectrum of the Mo ₁₃₂ cluster solution (10 mg/ml), and (b) is the ¹ H NMR spectrum of the product solution after the reaction.

13 shows HIFA yields and TONs according to the amount of Pd/C and Mo ₁₃₂ clusters or Pd/C and 6% Mo ₁₃₂ @MIL-100(Fe) catalyst.

14 (a) shows the N2 adsorption/desorption isotherm of the Pd/C catalyst, and (b) shows the pore size distribution of the Pd/C catalyst.

Figure 15 is (a) FA yield and TON (Pd), (b) HIFA when the 24-hour reaction was reused three times using 0.5 g Pd / C and 0.5 μmol 6% Mo 132 @MIL- ₁₀₀ (Fe) Yield and TON (Mo ₁₃₂ catalyst) are shown.

Hereinafter, the configuration of the present invention, including a preferred embodiment, in which a person skilled in the art to which the present invention pertains can easily practice the present invention will be described in detail. In describing the principles of preferred embodiments of the present invention in detail, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

The present invention relates to a method for improving the yield of formic acid by increasing the content of bicarbonate ions in a reaction solution reacted with a hydrogenation catalyst in a carbon dioxide conversion reaction in which carbon dioxide is hydrogenated and converted into formic acid under a non-basic condition. For this purpose, the present invention uses a hydration catalyst together with a carbon dioxide hydrogenation catalyst.

That is, in the carbon dioxide hydrogenation reaction of the present invention, a hydrogenation catalyst and a hydration catalyst are used together in the carbon dioxide hydrogenation reaction under anhydrous conditions, and the content of bicarbonate ions reacted with the hydrogenation catalyst through the hydration reaction of carbon dioxide by the hydration catalyst in the reaction solution It relates to a method for producing formic acid derived from carbon dioxide using a dual catalyst capable of increasing the yield of formic acid as a result (see Chemical Formula 1).

[Formula 1]

CO ₂ + H ₂ O -> HCO ₃ ^- + H ⁺ : Hydration catalyst

HCO ₃ ^- + H ⁺ + H ₂ -> HCOOH + H ₂ O : hydrogenation catalyst

Hereinafter, a method for producing formic acid from carbon dioxide using the dual catalyst according to the present invention will be described in more detail.

The method for producing formic acid from carbon dioxide using a dual catalyst according to the present invention includes a hydration catalyst that converts carbon dioxide into bicarbonate through a hydration reaction and a hydrogenation catalyst that converts bicarbonate into formic acid through a hydrogenation reaction. providing a catalyst; and reacting carbon dioxide, hydrogen, and water under the dual catalyst to produce bicarbonate ions by reacting carbon dioxide and water by the hydration catalyst, and producing formic acid by reacting the bicarbonate ions and hydrogen by the hydrogenation catalyst. includes;

In this case, the hydration catalyst is a carbon dioxide hydration catalyst having a structure imitating carbonic anhydrase (CA), and a Keplerate-type metal-containing nanocluster or a heterogeneous catalyst thereof is used.

More specifically, the present invention includes a Keplerate-type metal-containing nanocluster, including a Keplerate-type Mo ₁₃₂ cluster.

1 is a view showing the structure of a Mo ₁₃₂ cluster hydration catalyst used in a method for producing formic acid derived from carbon dioxide using a dual catalyst according to an embodiment of the present invention.

As shown in Figure 1, the Mo ₁₃₂ cluster is spherical [(NH ₄ ) ₄₂ [[Mo ^VI ] Mo ^VI ₅ O ₂₁ (H ₂ O) ₆ ] ₁₂ [Mo ^V ₂ O ₄ (CH ₃ COO)] ₃₀ ] ㆍ~300H ₂ Oㆍ~10CH ₃ COONH ₄ Forming 12 pentagonal [Mo ^VI ₆ ] units and 30 [Mo ^V ₂ ] linkers, Keplerate type anionic polyoxometallate (POM) am.

The Mo ₁₃₂ cluster has 20 flexible hexagonal holes (3.2 Å in diameter) that allow organic compounds to pass through, and 30 unstable acetate ligands coordinated to the [Mo ^V ₂ ] linker in a bidentate fashion are carbonate , can be easily replaced by other anions in aqueous solution, such as sulfate, fluoride, etc.

The Mo ₁₃₂ cluster has carbonic anhydrase (CA) mimic properties, and hydrates carbon dioxide through a ligand exchange process in which carbon dioxide is dissolved in an aqueous solution through protonation of a metal catalyst and nucleophilic addition of water to form bicarbonate ions and protons. Occurs at the [Mo ^V ₂ ] position (see Formula 2).

[Formula 2]

Considering that bicarbonate ions are more sensitive to hydrogenation than carbon dioxide, the presence of Mo ₁₃₂ clusters can increase the yield of FA from Pd catalyzed abasic CO ₂ hydrogenation (see Equation 3).

[Formula 3]

2 is a view showing the structure of a Mo ₁₃₂ @MIL-100(Fe) hydration catalyst used in the method for producing formic acid derived from carbon dioxide using a dual catalyst according to an embodiment of the present invention.

As shown in FIG. 2, the present invention is a heterogeneous catalyst of the Keplerate-type metal-containing nanocluster, and the Keplerate-type Mo ₁₃₂ cluster is formed into a metal organic framework (MOF) or zeolite already. It includes at least one of the composite catalysts encapsulated in a dazolate framework (ZIF), and in particular, a composite catalyst (Mo ₁₃₂ of Keplerate type) encapsulated in mesoporous iron trihydrochloride (MIL-100(Fe)). ₁₃₂ @MIL-100(Fe)) is preferred (see Formula 4).

[Formula 4]

The Mo _132- based hydration catalyst can be easily separated from the hydrogenation catalyst (eg, Pd/C) without leaching after the reaction, and thus has the advantage of being recycled for continuous reactions.

On the other hand, the hydrogenation catalyst is ruthenium (Ru), iridium (Ir), rhodium (Rh), platinum (Pt), palladium (Pd), silver (Ag), gold (Au), iron (Fe ), a metal or composite metal including at least one of cobalt (Co), nickel (Ni), copper (Cu), and zinc (Zn) supported on a support is used.

In addition, the support includes at least one selected from a carbonaceous material, a molecular sieve, a ceramic material, and a metal oxide.

As described above, the method for producing formic acid derived from carbon dioxide using a dual catalyst according to the present invention uses a hydrogenation catalyst and a carbon dioxide hydration catalyst having a structure imitating carbonic anhydrase (CA) as a dual catalyst, The formic acid conversion rate through hydrogenation can be improved by increasing the bicarbonate ion content.

Hereinafter, preferred reaction conditions for producing formic acid derived from carbon dioxide using the dual catalyst according to the present invention will be described.

In the method for producing formic acid derived from carbon dioxide using a dual catalyst according to the present invention, during the reaction, the pressure of carbon dioxide in a mixed solution of carbon dioxide, hydrogen, water and the dual catalyst is 5 to 100 bar, more preferably 20 to 50 bar. make it a bar

In addition, the ratio of carbon dioxide and hydrogen in the mixed solution of carbon dioxide, hydrogen, water, and the dual catalyst is the ratio of the number of moles converted to carbon dioxide and hydrogen, respectively, and the mole ratio of carbon dioxide / hydrogen is preferably 0.2 to 5, more preferably is 0.3 to 3.

In addition, the hydration catalyst is added in an amount of 0.001 to 10 parts by weight, more preferably, 0.01 to 1 part by weight based on 100 parts by weight of the water.

In addition, the hydrogenation catalyst is added in an amount of 0.01 to 5 parts by weight, more preferably 0.1 to 0.5 parts by weight, based on 100 parts by weight of the water.

In addition, the reaction temperature during the reaction is 5 to 100 ℃, the pressure is 10 to 200 bar, the reaction time is preferably 1 to 1000 hours, more preferably, the reaction temperature is 20 to 60 ℃, the pressure is 40 to 100 bar, and the reaction time is 1 to 24 hours.

The effects of the present invention will be described through examples below.

Catalyst Preparation Example 1

Mo of Keplerate type ₁₃₂ cluster manufacturing

A total of 1.6 g of N ₂ H ₄ ㆍH ₂ SO ₄ (12.2 mmol), 11.2 g of (NH ₄ ) ₆ Mo ₇ O ₂₄ ㆍ4H ₂ O (9 mmol) and 25 g of CH ₃ COONH ₄ were added to 500 mL of distilled water. After that, the solution was stirred for 10 minutes until a blue color was observed. Then 166 mL of 50% aqueous CH ₃ COOH was added until a green color was observed. The resulting reaction solution was stored in a 1 L Erlenmeyer flask at room temperature in contact with air for 4 days. The resulting dark brown solution was filtered through a glass frit, washed with 90% ethanol, ethanol and diethyl ether, and then the sample was dried in air overnight (see Fig. 3).

Catalyst Preparation Example 2

Mo ₁₃₂ Manufacturing @MIL-100(Fe)

Mo ₁₃₂ @ MIL-100(Fe) was prepared by adding Mo ₁₃₂ aqueous solution during room temperature synthesis of MIL-100(Fe). Mo ₁₃₂ solutions were prepared by dissolving 1 or 3 g of Mo ₁₃₂ clusters in 20 mL of H ₂ O. The ligand solution was prepared by dissolving 5.68 g of H ₃ BTC in 500 mL of 0.16M NaOH solution while ultrasonicating for 1 hour (pH = 12). An Fe(II) solution was prepared separately by dissolving 8.9 g of FeSO ₄ 7H ₂ O in 500 mL of H ₂ O (pH = 4.9).

As a result of neutralizing the pH to 7.25 while pouring the ligand solution into the Fe(II) solution, a dark green solution was observed. After stirring for 10 minutes so that the color changes to bright orange while being oxidized in contact with air, a Mo ₁₃₂ solution was added to the solution and stirred at room temperature for 24 hours.

The resulting brown precipitate was washed with H ₂ O and ethanol by centrifugation twice, respectively. The resulting solid was dried overnight in a vacuum oven at 50 °C.

Catalyst Preparation Example 3

Manufacturing MIL-100 (Fe)

MIL-100(Fe) was prepared in the same manner as in the method for preparing Mo ₁₃₂ @MIL-100(Fe), except that the Mo ₁₃₂ solution was not added.

The characteristics and ICP results of the catalysts prepared according to Catalyst Preparation Examples 1 to 3 are shown in Table 1 below.

division Fe (wt%) Mo (wt%) S _BET (m ² /g) V _t (mL/g) Mo _{132 cluster} - 46.0 109 0.17 MIL-100 (Fe) 21.0 - 1357 0.70 3% Mo ₁₃₂ @MIL-100 (Fe) 21.3 3.10 1696 0.87 6% Mo ₁₃₂ @MIL-100 (Fe) 20.8 6.44 1124 0.61 Pd/C - - 948 0.73

Catalyst characterization

The catalyst obtained according to the preparation example was imaged using SEM and EDS and is shown in FIG. 4 . 4 (a) is MIL-100 (Fe), (b) is a SEM image of 3% Mo ₁₃₂ @MIL-100 (Fe), (c) is 6% Mo ₁₃₂ @MIL-100 (Fe), Figure 4 (d) is a 3% Mo ₁₃₂ @MIL-100 (Fe) EDS map image.

As shown in FIG. 4, larger MIL-100(Fe) crystals were observed as more Mo ₁₃₂ clusters were added. In addition, as shown in FIG. 5, the average particle sizes of MIL-100 (Fe), 3% Mo ₁₃₂ @MIL-100 (Fe) and 6% Mo ₁₃₂ @MIL-100 (Fe) were 357, 607, and 1852, respectively. measured in nm. This indicates that the presence of Mo ₁₃₂ clusters affects the crystallization of the MIL-100(Fe) particles, and the EDS map image confirms a uniform distribution of Fe and Mo atoms throughout the entire crystal, confirming the structure of the MIL-100(Fe). indicates that the Mo ₁₃₂ cluster was successfully encapsulated.

6 shows the characteristics of each catalyst according to an embodiment of the present invention, (a) PXRD pattern, (b) TGA profile, (c) N ₂ adsorption-desorption isotherm, (d) pore size distribution is shown.

Referring to the PXRD pattern, it shows that the crystallinity of MIL-100(Fe) is maintained after encapsulation of Mo ₁₃₂ clusters. The absence of the Mo ₁₃₂ cluster peak indicates that it is well dispersed in the MIL-100 (Fe) structure (see (a) in FIG. 6).

Referring to the TGA profile, MIL-100 (Fe) starts to decompose at 320 °C, while 3% Mo ₁₃₂ @MIL-100 (Fe) and 6% Mo ₁₃₂ @MIL-100 (Fe) are at temperatures above 360 °C. Thermal decomposition appears to begin, resulting in improved thermal stability, which is due to improved crystallinity and interaction between the encapsulated Mo ₁₃₂ cluster and the MIL-100 (Fe) framework (see (b) in FIG. 6). .

Referring to the N ₂ adsorption-desorption isotherm, 3% Mo ₁₃₂ @MIL-100 (Fe) was found to have the highest BET surface area (1696 m ² /g) and pore volume (0.87 cm ³ /g) (Fig. 6 see (c)).

The pore size distribution results indicate that encapsulation of Mo ₁₃₂ clusters did not change the pore structure of MIL-100(Fe). Considering the molecular size of the Mo ₁₃₂ cluster (2.9 nm) and the cavity size of MIL-100 (Fe) (2.5 and 2.9 nm), it appears that the Mo ₁₃₂ cluster is encapsulated during the growth of the MOF particles, these results suggest that the Mo ₁₃₂ cluster indicates that provides a driving force for crystallization of MIL-100 (Fe) by a template effect (see (d) in FIG. 6).

Referring to the results of the XPS survey spectrum, the presence of Mo was confirmed in the Mo ₁₃₂ cluster and the three silver materials of 3% and 6% Mo ₁₃₂ @MIL-100 (Fe) (see FIG. 7).

8 shows characteristics of each catalyst according to an embodiment of the present invention, (a) an XPX spectrum, (b) a Raman spectrum, and (c) an FTIR spectrum. For reference, (i) is Mo ₁₃₂ cluster, (ii) is MIL-100 (Fe), (iii) is 3% Mo ₁₃₂ @MIL-100 (Fe), (iv) is 6% Mo ₁₃₂ @MIL-100 (Fe) is shown. The presence of inorganic moieties including Mo=O and Mo-O-Mo bonds and ligand groups including water, acetate and ammonium ions of the Mo ₁₃₂ cluster show characteristic vibrational bands in Raman and FTIR spectra.

Referring to the XPX spectrum, it shows that the deconvolution curve consists of Mo ^VI centered at 236.1 and 233.0 eV and Mo ^V centered at 234.8 and 231.8 eV, which indicates the oxidation of the Mo ₁₃₂ cluster. It indicates that the state was maintained after encapsulation (see (a) of FIG. 8).

Referring to the Raman spectrum of FIG. 8, the Mo ₁₃₂ cluster showed strong bands at 308, 369, 875 and 952 cm ⁻¹ , which can be assigned to the inorganic group. In Mo ₁₃₂ @MIL-100(Fe), the symmetric A _g- type vibration (875cm ^-1 ) of μ3-O atoms in the pentagonal [Mo ^VI ₆ ] part and the asymmetric stretching vibration of Mo=O _t (O _t = terminal oxygen) bonds (952 cm ⁻¹ ) was also observed. The x% Mo ₁₃₂ @MIL-100(Fe) material showed a weak band, whereas no such peak was observed in MIL-100(Fe) (see the arrow in FIG. 8). Another strong peak representing the bending vibration of the Mo=O _t bond (369 cm ^-1 ) was not observed for x% Mo ₁₃₂ @MIL-100(Fe).

The FTIR spectrum shows ligand groups (water, acetate, and ammonium ions) related to the Mo ₁₃₂ cluster in the range of 1350-1650 cm ^-1 (see (c) of FIG. 8). This is because the ligand group related to the Mo ₁₃₂ cluster is merged with the carboxylate group of MIL-100 (Fe), and it is impossible to confirm in the x% Mo ₁₃₂ @MIL-100 (Fe) structure. In addition, the symmetric stretching vibration of the Mo=O bond (967 cm ^-1 ) and the asymmetric stretching vibration (856 and 798 cm ^-1 ) of the Mo-O-Mo part appearing in the Mo ₁₃₂ cluster were found in MIL-100 (Fe), 6% Mo ₁₃₂ @MIL-100 (Fe) and 3% Mo ₁₃₂ @MIL-100 (Fe) did not appear.

As above, the spectral data indicate that the structural integrity of the Mo ₁₃₂ cluster was maintained after encapsulation, and the intensity or disappearance of some peaks in the Raman and FTIR spectra in the x% Mo ₁₃₂ @MIL-100(Fe) structure was reduced or disappeared, indicating that the MIL- It appears to be due to low loading, high dispersion or chemical interactions within the 100(Fe) structure.

For reference, each characteristic of the Mo ₁₃₂ catalyst according to the present invention was measured by the following method.

Powder X-ray diffraction (PXRD) patterns: measured using a diffractometer (PANanalytical Aeris) emitting Ni filtered Cu Kα radiation (40 kV, 15 mA, λ = 1.5406 Å) at a scan rate of 4°/min.

N ₂ adsorption and desorption isotherms: obtained at 77 K (Micromeritics 3Flex). Samples were activated for 12 hours at 100 °C under vacuum before analysis.

Specific surface area: The specific surface area was measured using the Brunauer-Emmett-Teller (BET) method.

Total pore volume: measured by the single-point method at P/P ₀ = 0.995.

Pore Size Distribution: Calculated using the Density Functional Theory (DFT) method.

Thermogravimetric analysis (TGA) of the catalyst: was performed using a thermal analyzer (Scinco, TGAN 1000). The sample was heated at a rate of 5 °C/min from 25 to 600 °C under a constant N ₂ flow of 30 mL/min.

Fourier transform infrared (FTIR) spectra: recorded on an FTIR spectrometer (Nicolet, MAGNA-IR 560) using KBr pellets.

Raman spectra: recorded at a laser excitation wavelength of 514 nm using a Raman spectrometer (Horiba, LabRAM HR Evolution).

Scanning electron microscopy (SEM) images: obtained at 10 kV accelerating voltage (Tescan, VEGA-II LSU).

Transmission electron microscopy (TEM) images: obtained with TEM (FEI tecnai GS-20 S-Twin) at an accelerating voltage of 200 kV.

ICP-AES (inductively coupled plasma-atomic emission spectroscopy): performed using a Thermo Fisher Scientific iCAP 6500Duo.

X-ray photon spectroscopy (XPS): performed using an AXIS SUPRA X-ray photoelectron spectrometer (Al-Kα, 15 kV, 15 mA) calibrated using a C 1s peak at 284.8 eV.

Proton Nuclear Magnetic Resonance (1H NMR) spectra of the liquid product: recorded on a Bruker 500MHz NMR spectrometer.

High performance liquid chromatography (HPLC) analysis: was performed using an HPLC system (Youngin, YL9100) equipped with a dual UV-vis detector and a refractive index detector at 218 nm. Organic products were separated on a column (Bio-Rad, Aminex HPX-87X) using 5 mM H ₂ SO ₄ as mobile phase at 0.5 mL/min at 45 °C column temperature.

CO pulse chemisorption: was performed at 40 °C with 10% CO/He gas using a Micromeritics Autochem II 2920 V5.02. Prior to analysis, the samples were pre-activated in a He flow (50 mL/min) at 250 °C for 1 hour and further reduced with 10% H ₂ /Ar gas (50 mL/min) at 250 °C for 1 hour.

test example

This was done in a 200 mL autoclave by adding a given amount of catalyst to 50 mL of water. The reactor was sealed and purged with N ₂ three times to remove residual air, then pressurized with CO ₂ and H ₂ (total 50 bar, CO ₂ /H ₂ = 1:1). The solution was stirred (500 rpm) for a predetermined reaction time (1 hour, 24 hours) at a specific temperature (20 to 80 °C).

After completion of the reaction, the solution was vacuum filtered to separate the catalyst. The obtained liquid product was again filtered through a 0.2 μm syringe filter and analyzed by HPLC and 1H NMR.

For catalyst recycling test, after reaction, the physical mixture of Mo ₁₃₂ catalyst and Pd/C was collected by filtration, washed with water and methanol to remove adsorbed organic compounds, and then dried in a vacuum oven at 50 °C overnight.

Catalyst performance was calculated through hydration-induced formic acid (HIFA) yield as shown in Equation 1 below at different reaction temperatures (20 to 80 °C).

[Calculation 1]

HIFA yield = Total FA yield - FA yield obtained by Pd/C homocatalyst

Turnover rates (TONs) of Pd/C were calculated as in Equation 2 below. where D is the dispersion of Pd atoms exposed on the surface (16.8%) obtained by CO pulse chemisorption (16.8%).

[Calculation 2]

TON(Pd) = (mol of FA produced)/(mol of Pd used × D)

TON of the Mo ₁₃₂ cluster and x% Mo ₁₃₂ @ MIL-100 (Fe) was calculated as shown in Equation 3 below.

[Calculation 3]

TON(Mo ₁₃₂ Catalyst) = (Mole of HIFA produced) / (Mo used ₁₃₂ moles of catalyst)

The production rate of FA for Pd/C was calculated as shown in Equation 4 below.

[Calculation 4]

(Production rate of FA) = (mol of FA produced)/(mol of Pd used × D × 1h)

The production rate of HIFA for the Mo ₁₃₂ catalyst was calculated as shown in Equation 5 below.

[Calculation 5]

(Production rate of HIFA) = (Mole of HIFA produced)/ (Mo used) ₁₃₂ moles of catalyst × 1h)

The Arrhenius plot was calculated by taking the natural logarithm of the Arrhenius equation as shown in Equation 6 below. where k = the calculated production rate, Ea = activation energy, R = gas constant (8.314 JㆍK ^-1 ㆍmol ^-1 ), T = reaction temperature (293, 313, 333K), A = pre-exponential factor. E _a for each reaction is Ea = -R × (slope).

[Calculation 6]

ln k = -E _a /R(1/T) + ln A

Test result

Baseless Carbon Dioxide Hydrogenation Using Pd/C Single Catalyst

As shown in FIG. 9 and Table 2, the performance of anhydrous CO ₂ hydrogenation using a Pd/C single catalyst was measured under the following reaction conditions.

Reaction conditions: 50mL H ₂ O, 50 bar (CO ₂ :H ₂ = 1:1), 0.5g Pd/C, 24 h

As a result of the measurement, 0.51 mmol of FA (10.1 mM) was obtained at 20° C. and the pH of the product solution was measured to be 3.4. The yield of FA decreased as the reaction temperature increased from 20 °C to 60 °C.

The distribution of dissolved inorganic carbon (DIC) composition in water is determined by the rates of hydration, protonation, and deprotonation of carbon dioxide, all of which are affected by temperature, but changes in the DIC distribution are negligible over moderate temperature ranges. Conversely, the solubility of carbon dioxide in water was found to decrease by 50% as the temperature increased from 20 to 60 °C. Therefore, it was found that the main cause of the low FA yield when using a Pd/C catalyst alone in anhydrous carbon dioxide hydrogenation was the low solubility of carbon dioxide.

For reference, the FA yield slightly increased at 80 ° C. This is because the hydrogenation rate affects the FA yield more than the carbon dioxide solubility at 60 ° C. or higher.

Mo ₁₃₂ Alkaline Carbon Dioxide Hydrogenation Using Clusters

In order to test the synergistic effect of the Mo ₁₃₂ cluster on the carbon dioxide hydrogenation reaction, the Mo ₁₃₂ cluster was added to the Pd/C catalyst reaction and the hydrogenation performance was measured under the following reaction conditions.

Reaction conditions: 50mL H2O, P=50 bar (CO2/H2=1), 0.1g (Table 3) or 0.5g (Tables 2, 4) Pd/C, x μmol Mo ₁₃₂ catalyst, 20°C, 24 h

As shown in FIG. 9 and Table 2, the FA yield increased in all temperature ranges in the presence of Mo ₁₃₂ clusters, showing catalytic activity.

In addition, as shown in Table 3, reactions performed with Mo ₁₃₂ clusters or Mo ₁₃₂ @MIL-100(Fe) without Pd/C did not produce FA, indicating that the Mo ₁₃₂ catalyst could hydrogenate carbon dioxide to FA. (see Entry 3 and 12 in Table 3).

Referring to FIG. 10, when using Pd/C and Mo ₁₃₂ clusters, the FA yield increased with increasing temperature, indicating the effect of catalytic carbon dioxide hydration by Mo ₁₃₂ clusters, that is, the exchange and release of acetate ligands into bicarbonate ions. caused by doing

In particular, as shown in Table 2, the FA yield and TON measured after adding the Mo ₁₃₂ cluster increased by 3.8 times and 2.8 times at 60 and 80 ° C, respectively, compared to the case of using Pd / C alone, and at 80 ° C, the maximum of 0.852 mmol FA yield is shown.

In addition, as shown in FIG. 9, the TON after adding the Mo ₁₃₂ cluster increased more than 10 times compared to the case of using Pd/C alone, and the hydration-induced formic acid (HIFA) yield increased as the temperature increased to 60 ° C. appeared to increase.

In order to confirm the initial production rate and calculate the activation energy (Ea) at 20 to 60 ° C., the reaction was performed for 1 hour with a Pd / C single catalyst and a double catalyst of Pd / C and Mo ₁₃₂ cluster (see FIG. 10), as a result of Mo It was shown that the addition of the ₁₃₂ cluster greatly improved the yield of FA.

In addition, Figure 11 shows the FA production rate for Pd and the production rate of HIFA for the Mo ₁₃₂ cluster, and the HIFA production rate (350 - 1242 mol _HIFA · mol _Mo132 ^-1 · h ^-1 ) from the Mo ₁₃₂ cluster is Pd / C It was much greater than the FA production rate from the catalyst (6.8-8.3 mol _FA • mol _surf.Pd ^-1 • h ^-1 ). This indicates that the CO hydration generated at the [Mo ^V ₂ ] linker site of the Mo ₁₃₂ cluster is much faster and more efficient than the CO hydrogenation on the Pd surface.

In addition, the Arrhenius plot based on the production rate was measured at 20 to 60 ° C (see FIG. 9 (d)). Ea for FA production by Pd/C catalyst was 7.3 kJ/mol. In contrast, when the reaction was performed with Pd/C and Mo ₁₃₂ clusters, the calculated Ea for FA production was lowered to 4.1 kJ/mol, because bicarbonate ions are quickly formed through the hydration of carbon dioxide by Mo ₁₃₂ clusters. am.

Bicarbonate ion (HCO ^3- ) is highly reactive, and the use of a carbon dioxide hydration catalyst increases the concentration of bicarbonate ion (HCO ^3- ) in the solution, which subsequently enhances the carbon dioxide hydrogenation ability of Pd/C. In order to investigate the ligand exchange related thereto, an aqueous solution of the Mo ₁₃₂ cluster was analyzed by NMR spectroscopy before and after anhydrous base carbon dioxide (see FIG. 12). As shown in FIG. 12, the ¹ H NMR spectrum of the Mo ₁₃₂ cluster solution shows two characteristic signals assigned to free and coordinated acetate ligands. Conversely, the corresponding product solution (entry 5 in Table 4) clearly shows that the acetate ligand of the Mo ₁₃₂ cluster is replaced and released.

Mo ₁₃₂ Cluster and Mo ₁₃₂ Comparison of catalytic activity of @MIL-100 (Fe)

As shown in Tables 3 and 4 and FIG. 13, when MIL-100 (Fe) was added to Pd/C, the FA yield was not improved, and it was confirmed that only the MIL-100 (Fe) support was catalytically inactive. . In addition, when 3% Mo ₁₃₂ @MIL-100 (Fe) and 6% Mo ₁₃₂ @MIL-100 (Fe) were added to Pd/C, respectively, it was found to have similar catalytic activity.

In addition, when 0.1 g of Pd/C was used, both Mo ₁₃₂ cluster-based catalysts (Mo ₁₃₂ clusters and 6% Mo ₁₃₂ @MIL-100(Fe)) improved the FA yield, but 6% Mo ₁₃₂ @MIL-100 ( Fe) showed slightly higher catalysis. This is due to the increased stability of Mo ₁₃₂ clusters due to the encapsulation or dispersion of the MIL-100 (Fe) structure. In addition, the yield of HIFA and the TON of Pd gradually improved with the increase of Mo ₁₃₂ clusters. However, the TONs of Mo ₁₃₂ clusters decreased as the amount of Mo ₁₃₂ clusters increased, which could be attributed to a decrease in solution pH as the reaction progressed or an insufficient amount of Pd to hydrogenate CO ₂ or HCO ₃ ^- , which delayed the hydrogenation rate. It is presumed to be because

In addition, increasing the amount of Pd/C to 0.5 g showed a significant difference in activity between the two catalysts. The overall trend of the catalytic activity of the Mo ₁₃₂ clusters was similar to that obtained with 0.1 g of Pd/C, with a slight improvement in the HIFA yield and TON of Mo ₁₃₂ clusters and a decrease in the TON of Pd. Conversely, when 6% Mo ₁₃₂ @MIL-100 (Fe) was used, the catalytic activity was significantly improved, with a HIFA yield of 1.143 mmol and a TON (Pd) of 41.8, which were 3.9 and 2.8 times higher than the Mo ₁₃₂ cluster. The TON based on the Mo ₁₃₂ catalyst was the highest at 1257 when 0.25 µmol of 6% Mo ₁₃₂ @MIL-100(Fe) was used. These results can be explained by the dispersion of the catalyst and the stability of Mo ₁₃₂ @MIL-100(Fe).

Many keplerate-type anionic polyoxometalates (POMs), including Mo ₁₃₂ clusters, exhibit self-assembly behavior in solvents and tend to aggregate into vesicular hollow molecules of tens of nanometers or larger through van der Waals interactions, electrostatic repulsion, and hydrogen bonding. It was confirmed that Mo ₁₃₂ clusters were adsorbed on the nanopores or surface of Pd/C (see FIG. 14).

When the Mo ₁₃₂ clusters are aggregated _, the surface area capable of reacting with carbon dioxide is lost and the catalytic _activity may be lowered. keep

As a result of ICP analysis of the product solution obtained from the Pd/C and Mo ₁₃₂ cluster catalysts, 21 ppm of Mo was detected. This was much lower than the Mo content (128 ppm) of the initial reaction solution. The degree of Mo ₁₃₂ cluster adsorption may be greater due to the larger surface area available when using 0.5 g of Pd/C, resulting in 6% Mo ₁₃₂ @MIL-100 with Mo ₁₃₂ clusters dispersed throughout the structure than Mo ₁₃₂ clusters. (Fe) was found to have higher catalytic activity.

Entry Mo ₁₃₂ cluster
(μmol) Temp (℃) FA yield
(mmol) HIFA yield
(mmol) TON (Pd) TON
(Mo ₁₃₂ catalyst) One - 20 0.507 - 12.9 - 2 - 40 0.394 - 10.0 - 3 - 60 0.223 - 5.6 - 4 - 80 0.305 - 7.7 - 5 0.5 20 0.682 0.175 17.3 351 6 0.5 40 0.724 0.329 18.3 649 7 0.5 60 0.843 0.621 21.4 1222 8 0.5 80 0.852 0.547 21.6 1077

Entry Mo ₁₃₂ catalyst Mo ₁₃₂ catalyst
amount (µmol) FA yield
(mmol) HIFA yield
(mmol) TON
(Pd) TON
(Mo ₁₃₂ catalyst) One - - 0.123 - 15.6 - 2 Mo ₁₃₂ cluster 0.25 0.206 0.083 26.0 331 ^3a Mo ₁₃₂ cluster 0.25 0.000 0.000 - 0 4 Mo ₁₃₂ cluster 0.5 0.241 0.118 30.5 236 5 Mo ₁₃₂ cluster 1.25 0.284 0.161 35.9 129 6 Mo ₁₃₂ cluster 2.5 0.322 0.199 40.7 80 7 3% Mo ₁₃₂ @MIL-100 (Fe) 2.5 0.340 0.217 43.1 87 8 6% Mo ₁₃₂ @MIL-100 (Fe) 2.5 0.341 0.218 43.2 87 9 6% Mo ₁₃₂ @MIL-100 (Fe) 1.25 0.303 0.180 38.3 144 10 6% Mo ₁₃₂ @MIL-100 (Fe) 0.5 0.253 0.130 32.0 260 11 6% Mo ₁₃₂ @MIL-100 (Fe) 0.25 0.210 0.087 26.6 348 ^12a 6% Mo ₁₃₂ @MIL-100 (Fe) 0.25 0.000 0.000 - 0 a: Reactions were conducted without Pd/C.

Entry Mo ₁₃₂ catalyst Mo ₁₃₂ catalyst
amount (µmol) FA yield
(mmol) HIFA yield
(mmol) TON
(Pd) TON
(Mo ₁₃₂ catalyst) One - - 0.507 - 12.8 - 2 MIL-100 (Fe) - 0.487 - 12.3 - 3 Mo ₁₃₂ cluster 0.25 0.620 0.113 15.7 452 4 Mo ₁₃₂ cluster 0.5 0.682 0.175 17.3 351 5 Mo ₁₃₂ cluster 1.25 0.735 0.228 18.6 182 6 Mo ₁₃₂ cluster 2.5 0.799 0.292 20.0 117 7 6% Mo ₁₃₂ @MIL-100 (Fe) 0.25 0.821 0.314 20.8 1257 8 6% Mo ₁₃₂ @MIL-100 (Fe) 0.5 0.988 0.481 25.0 963 9 6% Mo ₁₃₂ @MIL-100 (Fe) 1.25 1.294 0.787 32.8 629 10 6% Mo ₁₃₂ @MIL-100 (Fe) 2.5 1.650 1.143 41.8 457

Catalyst Recycling Test

In order to confirm the non-uniformity of Pd/C and 6% Mo ₁₃₂ @MIL-100 (Fe), three consecutive catalytic reactions were performed. A physical mixture of Pd/C and 6% Mo ₁₃₂ @MIL-100(Fe) was withdrawn at 24 h intervals throughout the reaction, washed with methanol and dried at 50 °C for the next cycle.

There was no significant loss of catalytic activity, FA and HIFA yield, or TON of catalyst (see Figure 15).

The liquid product solution was analyzed by ICP after each cycle and no Mo or Pd was detected at the 5 ppm detection limit, indicating that the Mo ₁₃₂ @MIL-100(Fe) composite reacted in a non-uniform manner without leaching of Mo ₁₃₂ clusters. prove that it catalyzes In addition, as a result of analyzing the recovered catalyst by PXRD and SEM, it was found that the crystallinity and octahedral particles of MIL-100 (Fe) were maintained (see FIG. 16).

The present invention has been described above with reference to the embodiments shown in the accompanying drawings, but these are only exemplary, and various modifications and other equivalent embodiments can be made by those skilled in the art in the art. will understand that Therefore, the technical protection scope of the present invention should be determined by the claims below.

Claims (10)

In the method for producing formic acid from carbon dioxide using a dual catalyst, Providing a dual catalyst comprising a hydration catalyst for converting carbon dioxide into bicarbonate ions through a hydration reaction and a hydrogenation catalyst for converting bicarbonate ions into formic acid through a hydrogenation reaction; and reacting carbon dioxide, hydrogen and water under the dual catalyst, reacting carbon dioxide and water by the hydration catalyst to produce bicarbonate ions, and reacting the bicarbonate ions and hydrogen by the hydrogenation catalyst to produce formic acid; Including, The hydration catalyst is a Keplerate-type metal-containing nano-cluster or a heterogeneous catalyst thereof, and the hydrogenation catalyst is an active metal in the catalyst composite, ruthenium (Ru), iridium (Ir), rhodium (Rh), platinum ( A metal containing at least one of Pt), palladium (Pd), silver (Ag), gold (Au), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and zinc (Zn) Alternatively, a method for producing formic acid derived from carbon dioxide using a dual catalyst, characterized in that the catalyst supported on a support is a composite metal. According to claim 1, The Keplerate type metal-containing nanocluster, A method for producing formic acid derived from carbon dioxide using a dual catalyst, characterized in that it is a Keplerate type Mo ₁₃₂ cluster. According to claim 1, The heterogeneous catalyst, A method for producing formic acid derived from carbon dioxide using a dual catalyst, characterized in that it is a composite catalyst in which Keplerate-type Mo ₁₃₂ clusters are encapsulated in a metal organic framework (MOF) or a zeolite imidazolate framework (ZIF). According to claim 3, The heterogeneous catalyst, Carbon dioxide using a dual catalyst, characterized in that it is a composite catalyst (Mo ₁₃₂ @MIL-100 (Fe)) in which Keplerate-type Mo ₁₃₂ clusters are encapsulated in mesoporous iron trihydrochloride (MIL-100 (Fe)) Method for producing derived formic acid. According to claim 1, The support is A method for producing formic acid derived from carbon dioxide using a dual catalyst, characterized in that at least one selected from carbonaceous materials, molecular sieves, ceramic materials, and metal oxides. According to claim 1, A method for producing formic acid derived from carbon dioxide using a dual catalyst, characterized in that the pressure of carbon dioxide in a mixed solution of carbon dioxide, hydrogen, water and a dual catalyst is 5 to 100 bar. According to claim 1, The ratio of carbon dioxide and hydrogen in the mixed solution of carbon dioxide, hydrogen, water and dual catalyst is the ratio of the number of moles converted to carbon dioxide and hydrogen, respectively, and the molar ratio of carbon dioxide / hydrogen is 0.2 to 5, using a dual catalyst Method for producing formic acid derived from carbon dioxide. According to claim 1, The hydration catalyst, A method for producing formic acid derived from carbon dioxide using a dual catalyst, characterized in that 0.001 to 10 parts by weight is added based on 100 parts by weight of the water. According to claim 1, The hydrogenation catalyst, A method for producing formic acid derived from carbon dioxide using a dual catalyst, characterized in that 0.01 to 5 parts by weight is added based on 100 parts by weight of the water. According to claim 1, In the method for producing formic acid derived from carbon dioxide using the dual catalyst, As the reaction conditions, the reaction temperature is 5 to 100 ° C, the pressure is 10 to 200 bar, and the reaction time is 1 to 1000 hours.

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