KR20200125498A - Platinum atom multiple doped gold nanocluster and method for producing the same, and catalyst for oxygen reduction reaction - Google Patents

Abstract

The present invention relates to a gold nanocluster doped with platinum atoms in multiple layers, a method for producing the same, and a catalyst for an oxygen reduction reaction of a gold nanocluster doped with platinum atoms in multiple layers. The present invention provides an effective catalyst for an oxygen reduction reaction by using electrochemical properties controlled by multiple doping of platinum atoms on the gold nanocluster, wherein the catalyst satisfies chemical formula 1: Pt_xAu_25-x(SR)_18.

Description

Platinum atom multiple doped gold nanocluster and method for producing the same, and catalyst for oxygen reduction reaction

The present invention relates to a gold nanocluster doped with multiple platinum atoms, a method for preparing the same, and a catalyst for oxygen reduction reaction.

A nanocluster or superatom composed of a certain number of metal atoms and ligands follows the macroatomic orbital theory, in which the valence electrons of the particles are newly defined, and this is considered to be one giant atom. It is a theory.

Nanoclusters are stable compared to one atom or nanoparticles, and have strong molecular properties than metallic properties, and thus have optical and electrochemical properties that are completely different from nanoparticles. In particular, as the optical, electrical and catalytic properties of nanoclusters are sensitively changed depending on the number of metal atoms, types of metal atoms, and ligands, research on nanoclusters is actively in progress in a wide variety of fields.

On the other hand, fuel cell technology is based on the generation of energy when hydrogen fuel is converted to water through an electrochemical reaction with oxygen, and is attracting attention as an eco-friendly next-generation energy source because of its high energy production efficiency and little pollution.

The fuel cell technology has the following reaction process. In particular, the reaction efficiency varies depending on how well the oxygen reduction reaction (ORR) occurs in the cathode (anode).

▶ anode (negative ^{_{electrode): 2H 2 → 4H + +}} 4e -

▶ reduction electrode ^{_{(cathode): O 2 + 4H + +}} 4e - → 2H 2 O

This is because there is an oxygen adsorption step with a high energy wall among the multi-step reactions of ORR, so the oxygen adsorption intensity acts as an important variable in determining the reaction efficiency of ORR.

Accordingly, in order to improve the reaction efficiency of the fuel cell, research on the development of a catalyst having an optimum oxygen adsorption strength is continuously conducted.

Up to now, platinum (Pt) having an optimized oxygen adsorption energy is mainly used as a catalyst, but the platinum (Pt) is a catalyst for an oxygen reduction reaction that can replace it as the price is high and the reserves are limited. Development is required.

Korean Patent Publication No. 10-1753662 is proposed as a prior document similar to this.

Korean Registered Patent Publication No. 10-1753662 (2017.06.28)

In order to solve the above problems, an object of the present invention is to provide a gold nanocluster doped with multiple platinum atoms and a method for preparing the same, and a catalyst for oxygen reduction reaction, which is inexpensive compared to platinum and has excellent oxygen reduction reaction activity. .

One aspect of the present invention relates to a catalyst for oxygen reduction reaction of a gold nanocluster doped with multiple platinum atoms satisfying the following formula (1).

[Formula 1]

Pt _x Au _25-x (SR) ₁₈

(In Formula 1, SR is an organic thiol-based ligand, and x is an integer selected from 2 to 13.)

Preferably, the organothiol-based ligand according to an embodiment of the present invention may be (C1-C10)alkylthiol.

In addition, another aspect of the present invention a) preparing a mixed metal salt of a gold precursor and a divalent platinum precursor; ,b) reacting the mixed metal salt with an organic thiol-based ligand compound in the presence of a catalyst; And c) adding a reducing agent to the reactant of step b) to prepare a gold nanocluster having multiple doped platinum atoms satisfying the following Formula 1; Containing, a method for producing a gold nanocluster doped with multiple platinum atoms will be.

[Formula 1]

Pt _x Au _25-x (SR) ₁₈

(In Formula 1, SR is an organic thiol-based ligand, and x is an integer selected from 2 to 13.)

Wherein in another embodiment, the gold precursor the molar ratio of divalent platinum precursor 1 may be 1 to 10, wherein the divalent platinum precursor, PtCl _2, PtBr _2, PtI _2, K ₂ PtCl _4, Na ₂ PtCl ₄ and H ₃ Pt(SO ₃ ) _{2 It} may be any one selected from the group consisting of OH, or two or more.

Preferably, the organothiol-based ligand according to an embodiment of the present invention may be (C1-C10)alkylthiol.

In addition, the present invention provides an electrode employing a gold nanocluster doped with a platinum atom of the present invention.

The catalyst for oxygen reduction reaction of gold nanoclusters doped with multiple platinum atoms according to the present invention has an advantage of being cheaper than a platinum catalyst composed of only expensive platinum, and excellent performance when used as a catalyst for oxygen reduction reaction.

In addition, the method of manufacturing a gold nanocluster doped with multiple platinum atoms according to the present invention has the advantage of being capable of multiple doping platinum atoms in a gold nanocluster by using a divalent platinum precursor.

In addition, since the electrode employing the gold nanoclusters doped with multiple platinum atoms of the present invention has high reaction efficiency, the fuel cell employing the electrode has excellent energy efficiency.

1 is an electrospray ionization mass spectrometry diagram of Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ and PtAu ₂₄ (SC ₆ H ₁₃ ) ₁₈ .
2 is an isotope pattern analysis data of Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ and PtAu ₂₄ (SC ₆ H ₁₃ ) ₁₈ .
3 is an ultraviolet-visible-near-infrared absorption spectrum of Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ and PtAu ₂₄ (SC ₆ H ₁₃ ) ₁₈ .
4 is a square wave voltagram analysis data of Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ and PtAu ₂₄ (SC ₆ H ₁₃ ) ₁₈ , the horizontal axis is voltage (V vs Fc ^+/0 ), and the vertical axis is current ( A).
5 is an oxygen reduction cycle voltage current diagram of the carbon black-nanocluster composite films prepared in Preparation Example 4 and Comparative Preparation Examples 1 to 3, respectively.
6 is data for confirming oxygen reduction reactivity using a rotating ring-disk electrode (RRDE) of the carbon black-nanocluster composite films each prepared in Preparation Examples 1 to 4 and Comparative Preparation Example 1, and the negative current is the disk current, The positive current is the ring current.
7 is data for analyzing oxygen reduction reactivity of the carbon black-nanocluster composite films each prepared in Preparation Examples 1 to 4 and Comparative Preparation Example 1, and the black solid line (indicated by circular dots) indicates the number of electrons that can participate in the oxygen reduction reaction ( n) is calculated, and the black dotted line (indicated by a triangular dot) is the data showing the rate of peroxide generation.
8 is data for confirming oxygen reduction reactivity using a rotating ring-disk electrode (RRDE) of the carbon black-nanocluster composite films each prepared in Preparation Example 4 and Comparative Preparation Examples 1 to 3, and the negative current is the disk current, The positive current is the ring current.
9 is data obtained by calculating the number of electrons (n) that can participate in the oxygen reduction reaction of the carbon black-nanocluster composite films prepared in Preparation Example 4 and Comparative Preparation Examples 1 to 3, respectively.
10 is a data showing the analysis of catalytic rate constants of the carbon black-nanocluster composite films prepared in Preparation Example 4 and Comparative Preparation Examples 1 to 3, respectively.
11 is a circulating voltage and current diagram of hydrogen generation using a linear scanning potential method of carbon black-nanocluster composite films prepared in Preparation Example 4 and Comparative Preparation Example 3, respectively.
FIG. 12 is data of analysis of conversion water for hydrogen generation reactions using a constant voltage decomposition method of carbon black-nanocluster composite films each prepared in Preparation Example 4 and Comparative Preparation Example 3. FIG.
13 is Tafel analysis data for hydrogen generation reactions of carbon black-nanocluster composite films prepared in Preparation Example 4 and Comparative Preparation Example 3, respectively.

Hereinafter, a gold nanocluster doped with multiple platinum atoms according to the present invention, a method for preparing the same, and a catalyst for oxygen reduction reaction according to the present invention will be described in detail with reference to the accompanying drawings. The drawings introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms, and the drawings presented below may be exaggerated to clarify the spirit of the present invention. Also, throughout the specification, the same reference numerals indicate the same elements.

At this time, unless there are other definitions in the technical terms and scientific terms used, they have the meanings commonly understood by those of ordinary skill in the technical field to which this invention belongs, and the gist of the present invention in the following description and accompanying drawings Descriptions of known functions and configurations that may be unnecessarily obscure will be omitted.

In addition, in describing the constituent elements of the present invention, terms such as first, second, A, B, (a) and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, order, or order of the component is not limited by the term.

The fuel cell technology includes the following reaction processes, and in particular, the reaction efficiency varies depending on how well the oxygen reduction reaction (ORR) takes place in the cathode (anode).

▶ anode (negative ^{_{electrode): 2H 2 → 4H + +}} 4e -

▶ reduction electrode ^{_{(cathode): O 2 + 4H + +}} 4e - → 2H 2 O

This is because there is an oxygen adsorption step with a high energy wall among the multiple step reactions of ORR, so the oxygen adsorption strength acts as an important variable in determining the reaction efficiency of ORR. Until now, platinum (Pt) is mainly used as the metal of the ORR catalyst, but the platinum (Pt) is not only expensive, but also has limited reserves, which has low economic feasibility and is a constraint that hinders commercialization.

Accordingly, as a result of intensifying research, the present inventors have found that gold nanoclusters doped with multiple platinum atoms have excellent oxygen reduction reactivity while being inexpensive compared to platinum to complete the present invention.

In detail, an aspect of the present invention relates to a catalyst for oxygen reduction reaction of a gold nanocluster doped with multiple platinum atoms satisfying the following Formula 1, and by satisfying the following Formula 1, the price is lower than that of platinum, but excellent for the oxygen reduction reaction. Can have activity.

[Formula 1]

Pt _x Au _25-x (SR) ₁₈

In Formula 1, SR is an organic thiol-based ligand, x is an integer selected from 2 to 13, and more preferably x may be an integer selected from 2 to 6. It is preferable that the doping water has excellent activity comparable to that of the platinum catalyst for the oxygen reduction reaction, and has high economic efficiency compared to the platinum catalyst.

In an example of the present invention, the organic thiol-based ligand SR is an alkanethiol having 1 to 30 carbon atoms, an arylthiol having 6 to 30 carbon atoms, a cycloalcanthiol having 3 to 30 carbon atoms, a heteroaryl thiol having 5 to 30 carbon atoms, It may be any one or two or more selected from the group consisting of a heterocycloalkane thiol having 3 to 30 carbon atoms and an aryl alkane thiol having 6 to 30 carbon atoms, and the organic thiol-based ligand is one or more hydrogen in the functional group is further substituted with a substituent or It may not be substituted, and the substituent is an alkyl group having 1 to 10 carbon atoms, a halogen group (-F, -Br, -Cl, -I), a nitro group, a cyano group, a hydroxy group, an amino group, an aryl group having 6 to 20 carbon atoms , An alkenyl group having 2 to 7 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a heterocycloalkyl group having 3 to 20 carbon atoms, or a heteroaryl group having 4 to 20 carbon atoms, provided that the carbon number of the organic thiol-based ligand described above is the number of carbon atoms of the substituent Does not include. In addition, in all functional groups including the alkyl group, the alkyl group may be linear or branched.

In a more specific example, the organothiol-based ligand is pentanethiol, hexanethiol, heptanethiol, 2,4-dimethylbenzenethiol, glutathione, thiopronin, thiolated poly(ethylene glycol), p-mercaptophenol, and (r-mercaptopropyl)-trimethoxysilane) may be any one or two or more selected from the group consisting of, but is not limited thereto.

In addition, another aspect of the present invention relates to a film for oxygen reduction reaction including a catalyst for oxygen reduction reaction of gold nanoclusters doped with a plurality of platinum atoms satisfying Formula 1 above. More specifically, the oxygen reduction film may include a platinum atom-doped gold nanocluster oxygen reduction catalyst satisfying Formula 1, a conductive material, and a polymer binder.

In an example of the present invention, a weight ratio of the catalyst for oxygen reduction reaction of the gold nanoclusters doped with multiple platinum atoms: the conductive material may be 1:5 to 20, preferably 1:08 to 15. The catalyst for oxygen reduction reaction of gold nanoclusters doped with multiple platinum atoms: When the weight ratio of the conductive material satisfies the above range, the catalyst for oxygen reduction reaction of gold nanoclusters doped with multiple platinum atoms can cover the surface of the conductive material with a single layer. It is good that it can reduce cost by using a catalyst and can show maximum catalyst efficiency.

In an example of the present invention, the conductive material may be a carbon material, but if it is commonly used in the art, it may be used without particular limitation. Specific examples of the carbon body may be any one or two or more selected from the group consisting of carbon black, super-p, activated carbon, hard carbon, and soft carbon, but is not limited thereto.

In one example of the present invention, the polymeric binder is used for solid fixation of a catalyst for oxygen reduction reaction of gold nanoclusters doped with multiple platinum atoms and a conductive material, and can be used without particular limitation if it is commonly used in the art. And, specifically, it may be, for example, Nafion. The amount of the polymeric binder added is not particularly limited as long as the catalyst for oxygen reduction reaction of gold nanoclusters doped with multiple platinum atoms and the conductive material are firmly fixed, and as a specific example, oxygen reduction in gold nanoclusters doped with multiple platinum atoms The weight ratio of the reaction catalyst: the polymer binder may be 1:0.01 to 3, preferably 1:0.1 to 1, but is not limited thereto.

In addition, another aspect of the present invention a) preparing a mixed metal salt of a gold precursor and a divalent platinum precursor; b) reacting the mixed metal salt with an organic thiol-based ligand compound in the presence of a catalyst; And c) adding a reducing agent to the reactant of step b) to prepare a gold nanocluster having multiple doped platinum atoms satisfying the following Formula 1; Containing, a method for producing a gold nanocluster doped with multiple platinum atoms will be.

[Formula 1]

Pt _x Au _25-x (SR) ₁₈

In Formula 1, SR is an organic thiol-based ligand, x is an integer selected from 2 to 13, and more preferably x may be an integer selected from 2 to 6. At this time, the SR of Formula 1 is the same as described above, and redundant descriptions are omitted.

In terms of obtaining more excellent reaction efficiency, preferably the organothiol-based ligand according to an embodiment of the present invention may be (C1-C10)alkylthiol.

As described above, in the method of manufacturing a gold nanocluster doped with multiple platinum atoms according to an exemplary embodiment of the present invention, the gold nanocluster may be doped with multiple platinum atoms by using a divalent platinum precursor. On the other hand, when a tetravalent platinum precursor is used, even if the amount of the platinum precursor is increased, only Pt ₁ Au ₂₄ (SR) ₁₈ doped with one platinum atom can be synthesized.

Hereinafter, each step of the method of manufacturing a gold nanocluster doped with multiple platinum atoms will be described in more detail.

First, a) a step of reacting a reaction solution including a gold precursor, a divalent platinum precursor, and a catalyst may be performed.

In an example of the present invention, the gold precursor may be used without particular limitation as long as it is commonly used in the art, and as a specific example, HAuCl ₄ , AuCl ₃ , potassium tetrachloride KAuCl ₄ and gold hydroxide Au (OH ) It may be any one or two or more selected from the group consisting of ₃ and the like, and preferably HAuCl ₄ is good in improving the synthesis efficiency.

In an example of the present invention, the divalent platinum precursor is Na ₂ PtCl ₄ , PtCl ₂ , PtBr ₂ , PtI ₂ , K ₂ PtCl ₄ and H ₃ Pt(SO ₃ ) It may be any one or more than two selected from the group consisting of ₂ OH, preferably Na ₂ PtCl ₄ It is the synthesis efficiency It's better to improve. As described above, by using a divalent platinum precursor, platinum atoms can be multiple-doped in a gold nanocluster, and when a tetravalent platinum precursor is used, even if the addition amount of the platinum precursor is increased, one platinum atom is doped Pt ₁ Au ₂₄ (SR ) Only ₁₈ can be synthesized.

Particularly preferably, in order to prepare a gold nanocluster doped with multiple platinum atoms, it is important to appropriately control the mixing ratio of the gold precursor and the divalent platinum precursor. When the molar ratio of the gold precursor to the divalent platinum precursor is large, only Pt ₁ Au ₂₄ (SR) ₁₈ doped with one platinum atom can be synthesized.

As a specific example, the molar ratio of the gold precursor: the divalent platinum precursor may be 1:1 to 10, more preferably 1:1 to 5, more preferably 1:1 to 3, particularly preferably 1:1 to Can be 1.5 In this range, gold nanoclusters multi-doped with platinum atoms can be well synthesized.

In one example of the present invention, the reaction catalyst may be used without particular limitation as long as it is commonly used in the art, and consisting of tetraoctyl ammonium bromide (TOAB) and tetraphenylphosphine bromide (PPh ₄ Br), etc. It may be any one or two or more selected from the group, preferably using tetraoctyl ammonium bromide (TOAB) is good in improving the reaction efficiency.

In an example of the present invention, the reaction solution of step a) may further include a solvent to improve the dissolution and reaction ease of the metal precursor, and the solvent is not particularly limited as long as it is commonly used in the art. Can be used. In a specific example, the solvent is water, alcohol having 1 to 5 carbon atoms, acetonitrile, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), acetone, tetrahydrofuran (THF), and 1,4-dioxane, etc. It may be any one or two or more mixed solvents selected from the group consisting of, and preferably tetrahydrofuran is used. 50 to 100 ml of the solvent may be added based on 1 mmol of the gold precursor, but is not limited thereto.

Next, b) adding an organic thiol-based ligand compound to the reaction solution may be performed.

In one example of the present invention, the organothiol-based ligand compound may be RSH, which is a compound before hydrogen falls compared to the SR, and as a specific example, an alkanethiol having 1 to 30 carbon atoms, an arylthiol having 6 to 30 carbon atoms , C3-C30 cycloalkanethiol, C5-C30 heteroarylthiol, C3-C30 heterocycloalkanethiol, C6-C30 arylalkanethiol, etc. Can be any one or two or more selected from the group consisting of In the organic thiol-based ligand, one or more hydrogens in the functional group may be further substituted or unsubstituted with a substituent, wherein the substituent is an alkyl group having 1 to 10 carbon atoms, a halogen group (-F, -Br, -Cl, -I ), nitro group, cyano group, hydroxy group, amino group, aryl group having 6 to 20 carbon atoms, alkenyl group having 2 to 7 carbon atoms, cycloalkyl group having 3 to 20 carbon atoms, heterocycloalkyl group having 3 to 20 carbon atoms or 4 to 20 carbon atoms It is a heteroaryl group, provided that the carbon number of the organic thiol-based ligand described above does not include the carbon number of the substituent. In addition, in all functional groups including the alkyl group, the alkyl group may be linear or branched.

In a more specific example, the organothiol-based ligand is pentanethiol, hexanethiol, heptanethiol, 2,4-dimethylbenzenethiol, glutathione, thiopronin, thiolated poly(ethylene glycol), p-mercaptophenol, and (r-mercaptopropyl)-trimethoxysilane) may be any one or two or more selected from the group consisting of, but is not limited thereto.

Preferably, the organothiol-based ligand according to an embodiment of the present invention may be (C1-C10) alkylthiol, preferably (C4-C10)alkylthiol in terms of having a more excellent effect, and specifically It may be butylthiol, isobutylthiol, neobutylthiol, tert-butylthiol, pentylthiol, hexylthiol, 2-hexylthiol, 3-hexylthiol, or heptylthiol, but is not limited thereto.

In an example of the present invention, the mixing ratio of the gold precursor and the organic thiol-based ligand compound may be a ratio commonly mixed in the art, and as a specific example, the molar ratio of the gold precursor: the organic thiol-based ligand compound is 1: It may be 1 to 10, more preferably 1: 2 to 8, even more preferably 1: 2 to 8. In such a range, the synthesis efficiency is excellent and reaction impurities can be reduced.

Next, c) adding a reducing agent to the reaction solution to which the organic thiol-based ligand compound is added to prepare a gold nanocluster doped with multiple platinum atoms satisfying the following Formula 1 may be performed.

In one example of the present invention, the reducing agent may be used without any particular limitation as long as it is commonly used in the art, and as a specific example, the reducing agent may be NaBH ₄ , triethylamine, carbon monoxide (CO), etc., but is limited thereto. It is not.

In addition, the reducing agent may be added 5 to 30 mmol based on 1 mmol of the gold precursor, but this is only an example and the present invention is not limited thereto.

In addition, after completion of the reaction in step c), an additional purification process may be further performed to obtain a gold nanocluster doped with multiple platinum atoms of high purity, and an additional purification process may be performed through a conventional method.

Hereinafter, a gold nanocluster doped with multiple platinum atoms according to the present invention, a method of manufacturing the same, and a catalyst for oxygen reduction reaction according to the present invention will be described in more detail through examples. However, the following examples are only one reference for describing the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

Further, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. The terms used in the description herein are merely for effectively describing specific embodiments and are not intended to limit the invention. In addition, the unit of the additive not specifically described in the specification may be a weight %.

[Example 1] Synthesis of Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈

HAuCl ₄ : Na ₂ PtCl ₄ was mixed in a molar ratio of 1:1 to prepare a mixed metal salt of 0.5 mmol in total.

The mixed metal salt and 0.58 mmol of tetraoctylammonium bromide (TOAB) were dissolved in 15 mL of THF, and then 1.25 mmol of n-hexanethiol (C ₆ H ₁₃ SH) was slowly added dropwise for 3 minutes. After stirring for 2 minutes, 5 mmol of NaBH ₄ (in 5 ml H ₂ O) was quickly added at once. The mixture was further stirred for 24 hours to synthesize Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ .

When the reaction was completed, the mixture was washed 5 times with water and methanol to remove impurities, extracted with dichloromethane, and dried.

In order to obtain high-purity Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ , it was extracted with a mixed solvent of acetonitrile:dichloromethane (volume ratio = 2: 1) and dried to obtain high-purity Pt ₂ Au ₂₃ (SC ₆ H _{13 ).} ) ₁₈ was obtained.

[Comparative Example 1] Au ₂₅ (SC ₆ H ₁₃ ) ₁₈

0.5 mmol of HAuCl ₄ and 0.58 mmol of tetraoctylammonium bromide (TOAB) were dissolved in 15 ml of THF, and then 2.5 mmol of n-hexanethiol (C ₆ H ₁₃ SH) was slowly added dropwise for 3 minutes. After stirring for 2 minutes, 5 mmol of NaBH ₄ (in 5 ml H ₂ O) was quickly added at once. By further stirring for 24 hours, Au ₂₅ (SC ₆ H ₁₃ ) ₁₈ was synthesized.

When the reaction was completed, the mixture was washed 5 times with water and methanol to remove impurities, extracted with dichloromethane, and dried.

To obtain high purity Au ₂₅ (SC ₆ H ₁₃ ) ₁₈ , extraction was performed with a mixed solvent of acetonitrile: dichloromethane (volume ratio = 2: 1) and dried to obtain high purity Au ₂₅ (SC ₆ H ₁₃ ) ₁₈ I did.

[Comparative Example 2] PtAu ₂₄ (SC ₆ H ₁₃ ) ₁₈

Except for using the tetravalent H ₂ PtCl ₆ instead of the divalent Na ₂ PtCl _4, all processes were performed in the same manner as in Example 1. As a result, only PtAu ₂₄ (SC ₆ H ₁₃ ) ₁₈ was synthesized.

[Production Example 1] 0.2 layer

After ultrasonically stirring 33.0 µl of tetrahydrofuran (THF) solution in which 200 µg of carbon black and 3.5 µl of Nafion are mixed for 2 hours or more, Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ prepared in Example 1 An additional 13.6 μg (in THF 16.0 μl) was added and ultrasonically dispersed for about 10 minutes to prepare a nanocluster-carbon black composite dispersion.

Next, the prepared nanocluster-carbon black composite dispersion was solution-deposited on a 1 cm2 area of the gas diffusion type microporous carbon electrode (Effects of gas diffusion layer (GDL) and micro porous layer (MPL); GDE) to form carbon black. -A nanocluster composite film was prepared.

At this time, the layer is the number of layers on which the nanoclusters are raised on the carbon black used as an electrode support, and the 0.2 layer means that the surface area of 20% of the total surface area of the carbon black is covered with nanoclusters, which is carbon black It was quantified by the ratio of the surface area measurement (BET) result and the sum of the cross-sectional area of the nanocluster (sum of the cross-sectional area of the nanocluster/the surface area of carbon black).

[Production Example 2] 0.1 layer

Except for using 8 μg of Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ , all processes were performed in the same manner as in Preparation Example 1.

[Production Example 3] 0.5 layer

Except for using Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ at 40 μg, all processes were performed in the same manner as in Preparation Example 1.

[Production Example 4] 1.0 layer

Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ was used in the same manner as in Preparation Example 1 except for using 80 ㎍.

[Comparative Preparation Example 1]

All processes were performed in the same manner as in Preparation Example 1 except for using a 46.6 µl tetrahydrofuran (THF) solution in which 200 µg of carbon black and 3.5 µl of Nafion were mixed without a nanocluster.

[Comparative Preparation Example 2]

Instead of using Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) _18, Au ₂₅ (SC ₆ H ₁₃ ) ₁₈ prepared in Comparative Example 1 was used, and all processes were performed in the same manner as in Preparation Example 1.

[Comparative Preparation Example 3]

Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ Instead of using PtAu ₂₄ (SC ₆ H ₁₃ ) ₁₈ prepared in Comparative Example 2, all the processes were performed in the same manner as in Preparation Example 1.

[Result Analysis]

1) Synthesis confirmation

The synthesis of gold nanoclusters doped with platinum atoms was confirmed through FIGS. 1 and 2.

In detail, FIG. 1 is an electrospray ionization mass spectrometry diagram of Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ and PtAu ₂₄ (SC ₆ H ₁₃ ) ₁₈ , showing that a nanocluster of a single composition was synthesized.

2 is an isotope pattern analysis data, it can be seen that the same isotope pattern is shown when compared with the calculated isotope pattern, from which Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ and PtAu ₂₄ (SC ₆ H ₁₃ ) It was confirmed that ₁₈ was successfully synthesized.

2) UV-IR absorption spectrum

3 is a result of UV-visible-near-infrared absorption spectrum measurement of Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ and PtAu ₂₄ (SC ₆ H ₁₃ ) ₁₈ , it was confirmed that almost similar absorption wavelengths were shown. Through this, it was confirmed that the structure of the nanocluster did not change significantly depending on the doping number of platinum atoms, and only the physical properties of the surface of the central metal were modified. In the case of Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ , one platinum atom is preferentially located in the center of the central metal, and the other atom may be located on the surface of the central metal.

3) Analysis of electrochemical properties

4 is a square wave voltagram analysis data of Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ and PtAu ₂₄ (SC ₆ H ₁₃ ) ₁₈ , the horizontal axis is voltage (V vs Fc ^+/0 ), and the vertical axis is current ( A).

As shown in FIG. 4, it was confirmed that Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ and PtAu ₂₄ (SC ₆ H ₁₃ ) ₁₈ showed a square wave voltagram of almost similar shape. Through this, it was confirmed once again that the structure of the nanocluster does not change significantly depending on the doping number of platinum atoms, and only the physical properties of the surface of the central metal are modified.

4) Confirmation of catalytic reactivity of carbon black-nanocluster composite film

5 is an oxygen reduction cycle voltage current diagram of the carbon black-nanocluster composite films prepared in Preparation Example 4 and Comparative Preparation Examples 1 to 3, respectively, of Preparation Example 4 in which Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ was added. It was confirmed that the film had the highest current density and thus had excellent oxygen reduction reaction activity.

6 is data for confirming oxygen reduction reactivity using a rotating ring-disk electrode (RRDE) of the carbon black-nanocluster composite films each prepared in Preparation Examples 1 to 4 and Comparative Preparation Example 1, and the negative current is the disk current, The positive current is the ring current.

As shown in FIG. 6, it was confirmed that the oxygen reduction reaction activity increased as the number of layers increased.

7 is data for analyzing oxygen reduction reactivity of the carbon black-nanocluster composite films each prepared in Preparation Examples 1 to 4 and Comparative Preparation Example 1, and the black solid line (indicated by circular dots) indicates the number of electrons that can participate in the oxygen reduction reaction ( n) is calculated, and the black dotted line (indicated by a triangular dot) is the data showing the rate of peroxide generation.

As shown in FIG. 7, it was found that the number of electrons (n) that can participate in the oxygen reduction reaction approaches 4 as the number of layers increases. This confirmed that it is a high-performance catalyst that moves four electrons at once.

8 is data for confirming oxygen reduction reactivity using a rotating ring-disk electrode (RRDE) of the carbon black-nanocluster composite films each prepared in Preparation Example 4 and Comparative Preparation Examples 1 to 3, and the negative current is the disk current, The positive current is the ring current.

As shown in FIG. 8, it was confirmed that the oxygen reduction reaction activity increased as the number of doping of platinum atoms increased.

9 is data obtained by calculating the number of electrons (n) that can participate in the oxygen reduction reaction of the carbon black-nanocluster composite films prepared in Preparation Example 4 and Comparative Preparation Examples 1 to 3, respectively.

As shown in Figure 9, in the case of Comparative Production Example 1 in which the nanocluster catalyst was not added, only two electrons participated in the reaction during a unit time, whereas Comparative Production Example 2 had 3 and Comparative Production Example 3 had 3.5 , In Preparation Example 4, it was confirmed that the oxygen reduction reaction activity increased as the number of doping of platinum atoms increased as four electrons participated in the reaction, and in particular, Preparation Example 4 in which Pt ₂ Au ₂₃ (SC ₆ H ₁₃ ) ₁₈ was added In the film of, a very fast ORR was observed in which 4 electrons participated in the reaction during a unit time.

FIG. 10 is data obtained by analyzing the catalytic rate constant of the carbon black-nanocluster composite films prepared in Preparation Example 4 and Comparative Preparation Examples 1 to 3, respectively, and Pt ₂ Au ₂₃ (SC ₆ H) for a unit time. ₁₃ ) It was confirmed that the film of Preparation Example 4 to which ₁₈ was added has the best oxygen reduction reaction activity.

11 to 13 are data confirming the hydrogen generation reactivity of the carbon black-nanocluster composite films each prepared in Preparation Example 4 and Comparative Preparation Example 3, and FIG. 11 is a hydrogen generation cycle voltage current diagram using a linear scanning potential method. , FIG. 12 is data for analysis of converted water for hydrogen generation reaction using a constant voltage decomposition method, and FIG. 13 is data for Tafel analysis for hydrogen generation reaction.

As shown in Figs. 11 to 13, when the platinum atom is located in the center of the central metal, it was confirmed that hydrogen gas is rapidly generated regardless of the number of doping of the platinum atom, through which hydrogen generation reaction (HER) and oxygen reduction It was confirmed that the reactive sites of the reaction (ORR) are separated, and that hydrogen reacts at the center of the core metal and oxygen at the surface of the core metal.

Although the present invention has been described through the above-specified matters and limited embodiments, this is only provided to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and the present invention pertains to Those of ordinary skill in the field can make various modifications and variations from these descriptions.

Therefore, the spirit of the present invention is limited to the described embodiments and should not be defined, and all things that are equivalent or equivalent to the claims as well as the claims to be described later fall within the scope of the spirit of the present invention. .

Claims (8)

A catalyst for oxygen reduction reaction of gold nanoclusters doped with multiple platinum atoms satisfying the following formula (1).
[Formula 1]
Pt _x Au _25-x (SR) ₁₈
(In Formula 1, SR is an organic thiol-based ligand, and x is an integer selected from 2 to 13.) The method of claim 1,
The organothiol-based ligand is a (C1-C10)alkylthiol, a gold nanocluster doped with multiple platinum atoms. a) preparing a mixed metal salt of a gold precursor and a divalent platinum precursor;
b) reacting the mixed metal salt with an organic thiol-based ligand compound in the presence of a catalyst; And
c) preparing a gold nanocluster doped with multiple platinum atoms satisfying the following formula (1) by adding a reducing agent to the reactant of step b);
Containing, a method of producing a gold nanocluster doped with multiple platinum atoms.
[Formula 1]
Pt _x Au _25-x (SR) ₁₈
(In Formula 1, SR is an organic thiol-based ligand, and x is an integer selected from 2 to 13.) The method of claim 3,
The gold precursor: the molar ratio of the divalent platinum precursor is 1: 1 to 10, a method of manufacturing a gold nanocluster doped with multiple platinum atoms. The method of claim 3,
The divalent platinum precursor is any one or two or more selected from the group consisting of PtCl ₂ , PtBr ₂ , PtI ₂ , K ₂ PtCl ₄ , Na ₂ PtCl ₄ and H ₃ Pt(SO ₃ ) ₂ OH, platinum valence multiple doping Method of manufacturing a gold nanocluster. The method of claim 3,
The gold precursor: the molar ratio of the organothiol-based ligand is 1: 1 to 10, a method of producing a gold nanocluster doped with platinum atoms multiplied. The method of claim 3,
The organothiol-based ligand is a (C1-C10)alkylthiol, a gold nanocluster doped with multiple platinum atoms. An electrode employing the gold nanoclusters multi-doped with the platinum atom of claim 1 or 2.

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