KR102385415B1 - Platinum atom multiple doped silver nanocluster and method for producing the same, and nanocluster catalyst for oxygen reduction reaction - Google Patents

Abstract

The present invention relates to a silver nanoclusters doped with multiple platinum atoms, a method for preparing the same, and a nanocluster catalyst for oxygen reduction reaction. It provides an effective catalyst.

Description

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

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

Nanoclusters or superatoms composed of a certain number of metal atoms and ligands follow the macroatomic orbital theory, in which the valence electrons of particles are newly defined, It's a theory.

Nanoclusters have optical and electrochemical properties completely different from nanoparticles because they are more stable than single atoms or nanoparticles, and have stronger molecular properties than metallic properties. In particular, as optical, electrical and catalytic properties of nanoclusters are sensitively changed according to the number of metal atoms, types of metal atoms, ligands, etc., research on nanoclusters is being actively conducted 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 into water through an electrochemical reaction with oxygen.

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

▶ Anode (cathode): 2H ₂ → 4H ⁺ + 4e ^-

▶ Cathode (anode): O ₂ + 4H ⁺ + 4e ^- → 2H ₂ O

This is because there is an oxygen adsorption step with a high energy wall among the multiple steps of the ORR reaction, and the oxygen adsorption strength acts as an important variable in determining the reaction efficiency of the ORR.

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

Until now, platinum (Pt) having an optimized oxygen adsorption energy has been mainly used as a catalyst, but as platinum (Pt) has a high price and limited reserves, it can be replaced as a catalyst for oxygen reduction reaction development is required.

As a similar prior document, Republic of Korea Patent Publication No. 10-1753662 has been proposed.

Republic of Korea Patent Publication No. 10-1753662 (2017.06.28)

In order to solve the above problems, the present invention is to provide a silver nanocluster doped with platinum atoms having multiple doped platinum atoms, which is inexpensive compared to platinum and has excellent oxygen reduction reaction activity, a method for preparing the same, and a nanocluster catalyst for oxygen reduction reaction do it with

One aspect of the present invention relates to silver nanoclusters doped with platinum atoms that satisfy Formula 1 below, and the silver nanoclusters doped with platinum atoms may be used for oxygen reduction reaction (ORR).

[Formula 1]

Pt _x Ag _25-x (SR) ₁₈

(In Formula 1, SR is an organothiol-based ligand, and x is an integer selected from 3 to 13.)

Preferably, the organothiol-based ligand according to an embodiment of the present invention may be (C6-C12)arylthiol unsubstituted or substituted with (C1-C4)alkyl.

In addition, another aspect of the present invention comprises the steps of: a) preparing a reaction solution by reacting a silver precursor and an organothiol-based ligand compound; b) adding a platinum precursor to the reaction solution; and c) adding a reaction catalyst and a reducing agent to the solution of step b) to prepare silver nanoclusters doped with multiple platinum atoms satisfying the following formula (1); it's about how

[Formula 1]

Pt _x Ag _25-x (SR) ₁₈

(In Formula 1, SR is an organothiol-based ligand, and x is an integer selected from 3 to 13.)

In another exemplary embodiment, the molar ratio of the silver precursor to the platinum precursor may be 1:1 to 10.

The molar ratio of the silver precursor to the organothiol-based ligand according to an embodiment of the present invention may be 1:1 to 10, and the silver precursor is AgNO ₃ , AgBF ₄ , AgCF ₃ SO ₃ , AgClO ₄ , AgO ₂ CCH ₃ and AgPF It may be any one or two or more selected from ₆ .

In addition, the present invention provides an electrode employing the silver nanoclusters doped with platinum atoms of the present invention.

The silver nanoclusters multi-doped with platinum atoms according to the present invention have an advantage in that the price is lower than that of a platinum catalyst composed of only expensive platinum, and when used as a catalyst for an oxygen reduction reaction, its performance is excellent.

1 is an ultraviolet-visible-infrared absorption spectrum of nanoclusters prepared in Example 1, Comparative Example 1, and Comparative Example 2, respectively.
FIG. 2 is a voltage-current diagram of Pt ₃ Ag ₂₂ (SR) ₁₈ nanoclusters prepared in Example 1. FIG.
3 is a hydrogen generation reactivity confirmation data using the cyclic voltammetry of the carbon black-nano-cluster composite film prepared in Preparation Example 1, Comparative Preparation Example 1 and Comparative Preparation Example 2;
Figure 4 is the oxygen reduction reactivity confirmation data using the cyclic voltammetry of the carbon black-nano-cluster composite film prepared in Preparation Example 1, Comparative Preparation Example 1 and Comparative Preparation Example 2;
5 is a rotational ring-disc electrode (RRDE) of carbon black-nano-cluster composite films prepared in Preparation Example 1, Comparative Preparation Example 1 and Comparative Preparation Example 2 confirming oxygen reduction reactivity.
6 shows the number of oxygen reduction electrons (n, The number of electrons) is calculated.

Hereinafter, a silver nanocluster multi-doped with platinum atoms, a manufacturing method thereof, and a nanocluster 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, like reference numerals refer to like elements throughout.

At this time, if there is no other definition in the technical terms and scientific terms used, it has the meaning commonly understood by those of ordinary skill in the art 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 components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, or order of the elements are not limited by the terms.

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

▶ Anode (cathode): 2H ₂ → 4H ⁺ + 4e ^-

▶ Cathode (anode): O ₂ + 4H ⁺ + 4e ^- → 2H ₂ O

This is because there is an oxygen adsorption step with a high energy wall among the multiple steps of the ORR reaction, and the oxygen adsorption strength acts as an important variable in determining the reaction efficiency of the ORR.

To date, platinum (Pt) has been mainly used as the metal of the ORR catalyst. However, platinum (Pt) is not only expensive but also has limited reserves, so it has low economic feasibility and is a constraint impeding commercialization.

Accordingly, as a result of intensifying research, the present inventors have completed the present invention by discovering that silver nanoclusters doped with platinum atoms have excellent oxygen reduction reactivity while being inexpensive compared to platinum.

In detail, an aspect of the present invention relates to a silver nanoclusters doped with platinum atoms that satisfy the following formula (1). Accordingly, the silver nanoclusters in which platinum atoms are multi-doped can be utilized as a catalyst for oxygen reduction reaction (ORR).

[Formula 1]

Pt _x Ag _25-x (SR) ₁₈

In Formula 1, SR is an organothiol-based ligand, x is an integer selected from 3 to 13, and more preferably, x may be an integer selected from 3 to 6. It is preferable because it has excellent activity comparable to that of a platinum catalyst for oxygen reduction reaction in the doping water and can have high economic efficiency compared to a platinum catalyst.

In one embodiment of the present invention, the organothiol-based ligand, SR, is an alkanethiol having 1 to 30 carbon atoms, an arylthiol having 6 to 30 carbon atoms, a cycloalkanethiol having 3 to 30 carbon atoms, a heteroarylthiol having 5 to 30 carbon atoms, It may be any one or two or more selected from the group consisting of heterocycloalkanethiol having 3 to 30 carbon atoms and arylalkanethiol having 6 to 30 carbon atoms, and the organothiol-based ligand is a functional group in which at least one hydrogen is further substituted with a substituent or It may not be substituted, and in this case, 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 hydroxyl 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, with the proviso that the above-described organothiol-based ligand has 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 may include pentanethiol, hexanethiol, heptanethiol, 2,4-dimethylbenzenethiol, glutathione, thiopronine, 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-C4)alkyl-substituted or unsubstituted (C6-C12)arylthiol, more preferably (C1-C4)alkyl-substituted (C6-C12) arylthiol, for example, phenylthiol, 2-methylphenylthiol, 3-methylphenylthiol, 4-methylphenylthiol, 2,3-dimethylphenylthiol, 2,4-dimethylphenylthiol, 2 ,5-dimethylphenylthiol, 2-6-dimethylphenylthiol, 2-ethylphenylthiol, 2,3-diethylphenylthiol or 2,4-diethylphenylthiol, but is not limited thereto.

In addition, another aspect of the present invention relates to a film for oxygen reduction reaction comprising silver nanoclusters in which platinum atoms satisfying Chemical Formula 1 are multi-doped, wherein the film for oxygen reduction reaction is an electrode for oxygen reduction reaction. can be utilized.

More specifically, the film for oxygen reduction reaction may include silver nanoclusters in which platinum atoms satisfying Chemical Formula 1 are multi-doped, a conductive material, and a polymer binder.

In an example of the present invention, the weight ratio of the silver nanoclusters doped with platinum atoms to the conductive material may be 1:5 to 20, preferably 1:8 to 18. When the weight ratio of the silver nanoclusters doped with multiple platinum atoms to the conductive material satisfies the above range, the silver nanocluster catalyst doped with multiple platinum atoms can cover the surface of the conductive material with a single layer, thereby reducing costs by using a minimum amount of catalyst. It is good because it can exhibit the maximum catalyst efficiency at the same time.

In one embodiment of the present invention, the conductive material may be a carbon material, but as long as 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, soft carbon, and the like, but is not limited thereto.

In an example of the present invention, the polymer binder is used for firmly fixing the silver nanoclusters doped with platinum atoms and the conductive material, and if it is commonly used in the art, it can be used without particular limitation, specifically For example, it may be Nafion or the like. The amount of the polymer binder to be added is not particularly limited as long as the amount of the silver nanoclusters doped with platinum atoms and the conductive material is firmly fixed. : 0.01 to 3, preferably 1:0.1 to 2, but is not limited thereto.

In addition, another aspect of the present invention comprises the steps of: a) preparing a reaction solution by reacting a silver precursor and an organothiol-based ligand compound; b) adding a platinum precursor to the reaction solution; and c) adding a reaction catalyst and a reducing agent to prepare silver nanoclusters in which platinum atoms are multi-doped, satisfying the following formula (1).

[Formula 1]

Pt _x Ag _25-x (SR) ₁₈

In Formula 1, SR is an organothiol-based ligand, x is an integer selected from 3 to 13, and more preferably, x may be an integer selected from 3 to 6. In this case, since SR in Formula 1 is the same as described above, redundant descriptions are omitted.

As such, in the manufacturing method according to an embodiment of the present invention, silver nanoclusters in which platinum atoms are multi-doped into silver nanoclusters can be manufactured by adjusting the amount of the platinum precursor added, and through this, the price is low compared to platinum and oxygen reduction It can be used as a catalyst for oxygen reduction reaction (ORR) with better activity for the reaction.

Hereinafter, each step of the method for manufacturing silver nanoclusters in which platinum atoms are multi-doped will be described in more detail.

First, a) may be performed to prepare a reaction solution by reacting the precursor and the organothiol-based ligand compound.

In an example of the present invention, the silver precursor may be used without particular limitation as long as it is commonly used in the art, and as a specific example, AgNO ₃ , AgBF ₄ , AgCF ₃ SO ₃ , AgClO ₄ , AgO ₂ CCH ₃ and AgPF ₆ It may be any one or two or more selected from the group consisting of, preferably AgNO ₃ It is good to improve the synthesis efficiency.

In an example of the present invention, the organothiol-based ligand compound may be RSH, which is a compound before hydrogen is dropped when compared to SR, and as a specific example, alkanethiol having 1 to 30 carbon atoms, 6 to 30 carbon atoms Any one or two selected from the group consisting of arylthiol, cycloalkanethiol having 3 to 30 carbon atoms, heteroarylthiol having 5 to 30 carbon atoms, heterocycloalkanethiol having 3 to 30 carbon atoms and arylalkanethiol having 6 to 30 carbon atoms, etc. or more, and in the organothiol-based ligand, one or more hydrogens in the functional group may be further substituted or unsubstituted with a substituent, in which case, 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 heterocycloalkyl group having 4 to carbon atoms It is a heteroaryl group of 20, with the proviso that the number of carbon atoms of the organothiol-based ligand described above does not include the number of carbon atoms 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 may include pentanethiol, hexanethiol, heptanethiol, 2,4-dimethylbenzenethiol, glutathione, thiopronine, 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-C4)alkyl-substituted or unsubstituted (C6-C12)arylthiol, more preferably (C1-C4)alkyl-substituted (C6-C12) arylthiol, for example, phenylthiol, 2-methylphenylthiol, 3-methylphenylthiol, 4-methylphenylthiol, 2,3-dimethylphenylthiol, 2,4-dimethylphenylthiol, 2 ,5-dimethylphenylthiol, 2-6-dimethylphenylthiol, 2-ethylphenylthiol, 2,3-diethylphenylthiol or 2,4-diethylphenylthiol, but is not limited thereto.

In an example of the present invention, the mixing ratio of the silver precursor and the organothiol-based ligand compound may be a mixing ratio conventionally in the art, and as a specific example, the molar ratio of the silver precursor: the organothiol-based ligand compound is 1: 1 to 10, more preferably 1: 2 to 5, even more preferably 1: 2.5 to 3.5. In such a range, the synthesis efficiency is excellent and the reaction impurities can be reduced.

In one embodiment of the present invention, the reaction solution of step a) may further include a solvent to improve the dissolution and reaction easiness of the metal precursor, and the solvent is not particularly limited as long as it is commonly used in the art. can be used As 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 a mixed solvent of two or more selected from the group consisting of, preferably a mixed solvent of tetrahydrofuran and methanol. By mixing methanol with tetrahydrofuran, the solubility of the silver precursor can be improved, thereby improving the synthesis efficiency. At this time, the mixing ratio of tetrahydrofuran and methanol is not particularly limited, and it is preferable to mix methanol sufficiently to dissolve the silver precursor. In one embodiment, tetrahydrofuran: methanol may be mixed in a volume ratio of 1: 0.01 to 1, more preferably 1: 0.05 to 0.5, even more preferably 1: 0.1 to 0.2 by volume. In addition, 50 to 100 ml of the solvent may be added based on 1 mmol of the silver precursor, but is not limited thereto.

Next, b) adding a platinum precursor to the reaction solution may be performed.

In one embodiment of the present invention, the platinum precursor may be used without particular limitation as long as it is commonly used in the art, H ₂ PtCl ₆ , 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 or two or more selected from the group consisting of OH, preferably PtCl ₂ It is better in improving the synthesis efficiency to use.

In particular, it is particularly important to appropriately control the mixing ratio of the silver precursor and the platinum precursor in order to prepare the silver nanoclusters in which platinum atoms are multi-doped. In the conventional case, as the molar ratio of the silver precursor and the metal precursor of the metal atom to be doped was adjusted to only about 24:1 to 24:5, the experiment was mainly conducted only in the above range even when doping the platinum atom. In this case, the platinum atom There was a problem in that multi-doped silver nanoclusters were not synthesized at all. That is, when the number of moles of the silver precursor compared to the platinum precursor is large, only PtAg ₂₄ (SR) ₁₈ doped with one platinum atom is synthesized, so it may be very important to appropriately control the mixing ratio of the silver precursor and the platinum precursor.

As a specific example, the molar ratio of the silver precursor to the platinum precursor may be 1:1 to 10, more preferably 1:1 to 5, even more preferably 1:1 to 3, particularly preferably 1:1 to 1.5 days. can In this range, silver nanoclusters in which platinum atoms are multi-doped can be well synthesized.

Next, a step of c) adding a reaction catalyst and a reducing agent to the solution of step b) may be performed to prepare silver nanoclusters in which platinum atoms satisfying Chemical Formula 1 are multi-doped.

In one embodiment of the present invention, the reaction catalyst and the reducing agent may be used without particular limitation as long as they are commonly used in the art. As a specific example, the reaction catalyst is tetraphenylphosphine bromide (PPh ₄ Br), tetraoctylammonium It may be bromide (TOABr), and the like, and the reducing agent may be NaBH ₄ , tetraethylamine, carbon monoxide (CO), or the like, but is not limited thereto.

In addition, the reaction catalyst may be added in an amount of 0.01 to 0.1 mmol based on 1 mmol of the silver precursor, and the reducing agent may be added in an amount of 1 to 3 mmol based on 1 mmol of the silver precursor, but this is only an example. It is not limited.

In addition, after completion of the reaction in step c), an additional purification process may be further performed in order to obtain highly pure silver nanoclusters doped with multiple platinum atoms, and the additional purification process may be performed through a conventional method.

In addition, the present invention provides an electrode employing the silver nanoclusters doped with platinum atoms of the present invention.

The electrode of the present invention employs silver nanoclusters multi-doped with platinum atoms as a catalyst for oxygen reduction reaction, so the reaction efficiency is high.

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

Also, 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 this invention belongs. The terminology used herein is for the purpose of effectively describing particular embodiments only and is not intended to limit the invention. In addition, the unit of additives not specifically described in the specification may be weight %.

[Example 1] Pt ₃ Ag ₂₂ (SPhMe ₂ ) ₁₈ synthesis

First, 0.66 mmol of 2,4-dimethylbenzenethiol (HSPhMe ₂ ) and 0.22 mmol (in 2 mL of methanol) of AgNO ₃ were placed in 15 mL of tetrahydrofuran (THF) and stirred for 20 minutes under an ice bath. .

Next, 0.22 mmol (in 1 ml THF) of PtCl ₂ and 0.014 mmol (in 0.5 ml methanol) of tetraphenylphosphine bromide (PPh ₄ Br) were sequentially added to the reaction solution, and 0.4 mmol (in 0.5 ml of NaBH ₄ ) H ₂ O) was added rapidly in one portion. Then, by further stirring for 4 hours, Pt ₃ Ag ₂₂ (SPhMe ₂ ) ₁₈ was synthesized.

When the reaction was completed, after aging for 12 hours, the supernatant and the precipitate were separated by centrifugation, and the precipitate was dried, and then washed with 5 ml of dichloromethane (CH ₂ Cl ₂ ) and 15 ml of methanol to remove impurities.

To obtain high-purity Pt ₃ Ag ₂₂ (SPhMe ₂ ) ₁₈ , about 3 mg of Pt ₃ Ag ₂₂ (SPhMe ₂ ) ₁₈ was dissolved in 0.5 ml of dichloromethane and then 5 ml of n-hexane (C ₆ H ₁₄ ) was added for recrystallization.

[Comparative Example 1] Ag ₂₅ (SPhMe ₂ ) ₁₈

First, 0.66 mmol of 2,4-dimethylbenzenethiol (HSPhMe ₂ ) and 0.22 mmol (in 2 mL of methanol) of AgNO ₃ were placed in 15 mL of tetrahydrofuran (THF) and stirred for 20 minutes under an ice bath. .

Next, 0.014 mmol (in 0.5 mL of methanol) of tetraphenylphosphine bromide (PPh ₄ Br) was added to the reaction solution, and 0.4 mmol (in 0.5 mL of H ₂ O) of NaBH ₄ was rapidly added at once. Then, by further stirring for 4 hours, Ag ₂₅ (SPhMe ₂ ) ₁₈ was synthesized.

[Comparative Example 2] PtAg ₂₄ (SPhMe ₂ ) ₁₈

All processes were carried out in the same manner as in Example 1, except that the amount of AgNO ₃ 0.22 mmol and PtCl ₂ 0.18 mmol was changed. As a result, only PtAg ₂₄ (SPhMe ₂ ) ₁₈ was synthesized.

[Production Example 1]

33.0 μl of a tetrahydrofuran (THF) solution in which 200 μg of carbon black and 3.5 μl of Nafion were mixed was ultrasonically stirred for 2 hours or more, and then 13.6 μg of Pt ₃ Ag ₂₂ (SPhMe ₂ ) ₁₈ prepared in Example 1 (in THF 13.5 μl) was additionally added and ultrasonic dispersion was performed 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 gas diffusion type micropore carbon electrode (Effects of gas diffusion layer (GDL) and micro porous layer (MPL); GDE) having an area of 1 cm 2 to carbon black - A nanocluster composite film was prepared.

[Comparative Preparation Example 1]

All processes were the same as in Preparation Example 1 except that Ag ₂₅ (SPhMe ₂ ) ₁₈ prepared in Comparative Example 1 was used.

[Comparative Preparation Example 2]

Except for using the PtAg ₂₄ (SPhMe ₂ ) ₁₈ prepared in Comparative Example 2, all processes were performed in the same manner as in Preparation Example 1.

[Result analysis]

1) UV-IR absorption spectrum

1 is a measurement result of ultraviolet-visible-near-infrared absorption spectra of nanoclusters prepared in Example 1, Comparative Example 1, and Comparative Example 2, respectively.

As shown in FIG. 1 , in the case of Pt ₃ Ag ₂₂ (SPhMe ₂ ) ₁₈ doped with platinum atoms, a new absorption band was observed in the near-infrared region.

2) Analysis of electrochemical properties

2 is a square wave voltammogram analysis data of Pt ₃ Ag ₂₂ (SPhMe ₂ ) ₁₈ doped with multiple platinum atoms. The horizontal axis is voltage (V vs AgQRE), and the vertical axis is current (A).

As shown in FIG. 2 , unlike PtAg ₂₄ (SPhMe ₂ ) ₁₈ (a) doped with one platinum atom, Pt ₃ Ag ₂₂ (SPhMe ₂ ) ₁₈ (b) doped with multiple platinum atoms is the peak of the voltage-amplitude diagram. The interstitial spacing is halved, which means that the structure degeneracy is accompanied by a change in the electronic structure.

Specifically, in Pt ₃ Ag ₂₂ (SPhMe ₂ ) ₁₈ doped with multiple platinum atoms, one platinum atom is preferentially located at the center metal center, and the other two platinum atoms may be located on the center metal surface. Platinum atoms located at the center of the central metal are difficult to adsorb with oxygen due to the physical constraints of the surrounding silver atoms, but platinum atoms located on the surface of the central metal have an open structure, so smooth oxygen adsorption may be possible.

3) Confirmation of catalytic reactivity of carbon black-nano-cluster composite film

3 is a hydrogen production reactivity confirmation data using the cyclic voltammetry of the carbon black-nano cluster composite film prepared in Preparation Example 1, Comparative Preparation Example 1 and Comparative Preparation Example 2, respectively, and FIG. 4 is a cyclic voltammetry diagram. This is the data used to confirm the oxygen reduction reactivity.

As shown in FIG. 3 , in the carbon black-nanocluster composite films prepared in Preparation Example 1 and Comparative Preparation Example 1, respectively, it was confirmed that hydrogen gas was rapidly generated regardless of the doping number of platinum atoms.

On the other hand, as shown in FIG. 4, in the carbon black-nanocluster composite films prepared in Preparation Example 1, Comparative Preparation Example 1 and Comparative Preparation Example 2, respectively, the nanoclusters doped with platinum atoms have a higher current density with respect to ORR. From this, it was confirmed that the active points of the hydrogen evolution reaction and the oxygen reduction reaction are separated from each other, and the fact that the reaction occurs at the center of the central metal and oxygen at the surface of the central metal.

5 and 6 are data for confirming oxygen reduction reactivity using a rotating ring-disk electrode (RRDE) of the carbon black-nano-cluster composite film prepared in Preparation Example 1, Comparative Preparation Example 1 and Comparative Preparation Example 2, respectively, FIG. is a voltage (V vs. RHE)-current (A) graph, Figure 6 is the data obtained by calculating the number of oxygen reduction electrons (n).

As shown in FIGS. 5 and 6 , before platinum atoms are doped, Ag ₂₅ (SPhMe ₂ ) ₁₈ participates in the reaction of 2.5 electrons per unit time, whereas Pt ₃ Ag ₂₂ (SPhMe ₂ ) doped with platinum atoms multiple times. ₁₈ induced a faster oxygen reduction reaction, and it was confirmed by using the RRDE technique that it is a high-performance catalyst that moves three electrons at once.

As an open structure, the platinum atom located on the surface of the central metal acts as a reaction active site and induces smooth oxygen adsorption. Fast ORR, in which a large number of electrons participate in the reaction for a unit time by rapidly receiving hydrogen from the platinum atom located in the center of the central metal. This was observed.

Although the present invention has been described with reference to specific matters and limited examples as described above, these are only provided to help a more general understanding of the present invention, and the present invention is not limited to the above examples, and the present invention belongs to Various modifications and variations are possible from these descriptions by those of ordinary skill in the art.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and not only the claims to be described later, but also all those with equivalent or equivalent modifications to the claims will be said to belong to the scope of the spirit of the present invention. .

Claims (8)

A catalyst for oxygen reduction reaction (ORR) comprising silver nanoclusters in which platinum atoms are multi-doped, which satisfies the following formula (1).
[Formula 1]
Pt _x Ag _25-x (SR) ₁₈
(In Formula 1, SR is an organothiol-based ligand, and x is an integer selected from 3 to 13.) delete The method of claim 1,
In Chemical Formula 1, the organothiol-based ligand is a (C6-C12)arylthiol substituted with (C1-C4)alkyl. A catalyst for oxygen reduction reaction (ORR) comprising silver nanoclusters doped with platinum atoms. a) preparing a reaction solution by reacting a silver precursor and an organothiol-based ligand compound;
b) adding a platinum precursor to the reaction solution; and
c) adding a reaction catalyst and a reducing agent to the solution of step b) to prepare silver nanoclusters in which platinum atoms are multi-doped;
A method for producing a catalyst for oxygen reduction reaction (ORR) comprising silver nanoclusters in which platinum atoms are multi-doped.
[Formula 1]
Pt _x Ag _25-x (SR) ₁₈
(In Formula 1, SR is an organothiol-based ligand, and x is an integer selected from 3 to 13.) 5. The method of claim 4,
The molar ratio of the silver precursor to the platinum precursor is 1:1 to 10. 5. The method of claim 4,
A method for preparing a catalyst for oxygen reduction reaction (ORR) comprising silver nanoclusters multi-doped with platinum atoms having a molar ratio of the silver precursor: the organothiol-based ligand of 1:1 to 10. 5. The method of claim 4,
The silver precursor is AgNO ₃ , AgBF ₄ , AgCF ₃ SO ₃ , AgClO ₄ , AgO ₂ CCH ₃ Any one or more platinum atoms selected from the group consisting of AgPF ₆ Oxygen reduction reaction comprising a multi-doped silver nanoclusters A method for preparing a catalyst for (ORR). An electrode employing a catalyst for oxygen reduction reaction (ORR) comprising silver nanoclusters in which platinum atoms of claim 1 or 3 are multi-doped.

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