WO2024005470A1

WO2024005470A1 - Catalyst for applying electrochemical reaction and preparation method therefor

Info

Publication number: WO2024005470A1
Application number: PCT/KR2023/008828
Authority: WO
Inventors: 이효영; 쿠마아쉬와니; 실람바라산 페루말
Original assignee: 성균관대학교산학협력단; 기초과학연구원
Priority date: 2022-06-27
Filing date: 2023-06-26
Publication date: 2024-01-04
Also published as: KR20240001685A

Abstract

The present invention is for providing a catalyst comprising a single atom metal and a preparation method therefor, the catalyst comprising: a nitrogen-doped carbon matrix; and a single atom metal bonded to nitrogen in the carbon matrix.

Description

Catalysts for application in electrochemical reactions and methods for their preparation

The present invention relates to catalysts and methods for their preparation for applications in electrochemical reactions.

Because of its high energy storage density and zero carbon emissions, hydrogen (H ₂ ) fuel from water electrolysis has been considered the most promising alternative to fossil fuels. In this regard, the hydrogen evolution reaction (HER) refers to a reaction that electrochemically splits water for energy conversion.

The environment in which the hydrogen generation reaction takes place can be divided into strong acid, neutral, and strong base. Water can be electrolyzed in various environments, such as proton exchange membrane electrolysis in strong acid, seawater electrolysis in neutral medium, and commercial water electrolysis in strong base. To meet these requirements, HER catalysts that have excellent performance in acidic and alkaline media and are versatile at pH are attracting attention. Among these, there are platinum (Pt) and Pt-based catalysts, but they require limited availability and high cost to produce hydrogen. This is a factor that hinders the commercialization of the reaction.

Meanwhile, single atom catalysts (SACs), which have nearly 100% atomic economy and unique electronic properties compared to typical nanoparticles (NPs), are being studied in various fields. Specifically, most SACs contain an isolated single metal moiety coordinated with adjacent nitrogen atoms in a carbon matrix (M-NC), which can drive catalytic reactions with simple elementary reactions alone. However, limitations exist that severely limit the possibilities for further modification of the active site in SAC due to the simplicity of the single atom.

Korean Patent Publication No. 10-2182553, which is the background technology of this application, is about a method for producing a single atom catalyst supported on a carbon carrier. The registered patent discloses a method of supporting heterogeneous elements other than carbon on a carbon carrier through a dry gas phase process.

The purpose of the present application is to solve the problems of the prior art described above and to provide a catalyst containing a single atom metal and a method for producing the same.

In addition, the present application aims to provide a catalyst for hydrogen generation reaction comprising the above catalyst.

In addition, the present application aims to provide a catalyst for carbon dioxide reduction comprising the above catalyst.

Additionally, the present application aims to provide a catalyst for nitrogen reduction, including the catalyst.

In addition, the present application aims to provide a catalyst for electrochemical reaction, including the catalyst.

However, the technical challenges sought to be achieved by the embodiments of the present application are not limited to the technical challenges described above, and other technical challenges may exist.

To solve the above-described technical challenges, the present application provides a catalyst.

According to one embodiment, the catalyst may include a nitrogen-doped carbon matrix and a single atom metal bonded to nitrogen in the carbon matrix.

According to one embodiment, the single atom metal may include one type of single atom metal or a single atom dimer in which two types of single atom metals are combined.

According to one embodiment, the single atom dimer includes a first single atom metal bonded to nitrogen in the carbon matrix, and a second single atom metal bonded to nitrogen that is not bonded to the first single atom metal, It may include a combination of the first single atomic metal and the second single atomic metal.

According to one embodiment, the first single-atomic metal and the second single-atomic metal may include different elements.

According to one embodiment, the first single-atomic metal and the second single-atomic metal may include the same metal.

According to one embodiment, as a result of Fourier transform EXAFS (Extended It can include big things.

According to one embodiment, the catalyst may include one in which no chemical bond is observed between the single-atom metal and carbon as a result of XPS analysis.

According to one embodiment, the single atomic metal is Ni, Co, Sc, Ti, V, Cr, Mn, Fe, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd , Hf, Ta, W, Re, Os, Ir, Pt, Au, Ag, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and It may contain atoms selected from the group consisting of combinations thereof.

According to one embodiment, the catalyst may include one used in a reaction to reduce water (H ₂ O) to produce hydrogen (H ₂ ).

According to one embodiment, the catalyst may include one used in a reaction to reduce carbon dioxide (CO ₂ ) to produce ethanol and acetone.

According to one embodiment, the catalyst may include one used in a reaction to reduce nitrogen (N ₂ ) to produce ammonia.

According to another embodiment, the catalyst includes a base structure in which some of the carbon constituting the carbon matrix is replaced with nitrogen, and a single atom dimer bonded to nitrogen in the base structure, wherein the single The atomic dimer includes a first single-atomic metal bonded to nitrogen in the base structure, and a second single-atomic metal bonded to nitrogen that is not bonded to the first single-atomic metal, wherein the first single-atomic metal and the It may include a second single-atom metal bonded thereto.

In order to solve the above-mentioned technical problems, the present application provides a method for producing a catalyst.

According to one embodiment, the method for preparing the catalyst includes mixing a precursor of a carbon matrix and a precursor of a single-atom metal, self-polymerizing the precursor of the carbon matrix to form a carbon polymer, and the carbon polymer and a nitrogen source. It may include mixing and heat treatment.

According to one embodiment, the carbon polymer may include a precursor of the single-atom metal therein.

According to one embodiment, by the heat treatment, the precursor of the single atom metal becomes a single atom dimer of one type of single atom metal or two types of single atom metal, and the carbon polymer is a carbon matrix. It can be.

According to one embodiment, the precursor of the carbon matrix may include dopamine, and the carbon polymer may include poly dopamine.

According to the above-described means of solving the problem of the present application, the catalyst according to the present application is for electrochemical hydrogen evolution reaction (HER) in acid and alkaline media, and has pH-general performance similar to that of the Pt/C catalyst and compared to the expensive Pt metal. Since inexpensive metals can be used, manufacturing costs can be lowered.

In addition, the method for producing a catalyst according to the present disclosure can provide a method for synthesizing a new single atom dimer (SAD) catalyst containing two metals linked to each other.

In addition, the electrode for hydrogen generation reaction containing the catalyst according to the present disclosure shows high stability in an acidic or basic environment, has high reproducibility, and can have a constant degree of hydrogen generation.

Additionally, the catalyst according to the present disclosure comprises a single atom dimer. In this regard, with small loadings of the single atom dimeric metal, the HER mass activity (i.e., HER production per gm of metal) of the dimer can be similar to or higher than that of common commercial Pt and/or nanoparticles.

Additionally, the method for preparing a catalyst according to the present disclosure can provide a general synthetic route for obtaining various single atom dimers for complex catalytic reactions.

Additionally, the catalyst according to the present disclosure can be used in a reaction that reduces carbon dioxide (CO ₂ ) to produce ethanol and acetone.

Additionally, the catalyst according to the present disclosure can be used in a reaction that reduces nitrogen (N ₂ ) to produce ammonia.

However, the effects that can be obtained herein are not limited to the effects described above, and other effects may exist.

1A and 1B are schematic diagrams of a catalyst according to an embodiment of the present application.

Figure 2 is a flowchart showing a method for producing a catalyst according to an embodiment of the present application.

Figure 3 is a schematic diagram showing a method for producing a catalyst according to an embodiment of the present application.

Figure 4 is a schematic diagram showing a method for producing a catalyst containing metal nanoparticles.

Figures 5a and 5b are graphs showing XRD patterns of catalysts according to an example and a comparative example of the present application.

Figure 5c is a HADDF-STEM image of a catalyst according to an example of the present application.

FIG. 5D is an intensity profile and electron energy spectrum graph for site A in FIG. 5C.

FIG. 5E is an intensity profile and electron energy spectrum graph for site B in FIG. 5C.

Figure 5f is a graph showing the average dimer distance of a catalyst according to an example of the present application.

Figure 5g is an EDS image of a catalyst according to an example of the present application.

Figure 6a is a XANES (X-ray absorption near edge structure) spectrum graph of a catalyst according to an example and a comparative example of the present application.

Figure 6b is a XANES spectrum graph of a catalyst according to an example and a comparative example of the present application.

Figure 6c is a Fourier transform EXAFS (Extended X-ray. Absorption Fine Structure) spectrum graph of a catalyst according to an example and a comparative example of the present application.

Figure 6d is a Fourier transform EXAFS spectrum graph of a catalyst according to an example and a comparative example of the present application.

Figure 6e is a WT-EXAFS image of a catalyst according to an example and a comparative example of the present application.

Figure 7a is a graph showing the LSV polarization curve of a catalyst for hydrogen generation reaction according to an example and a comparative example of the present application.

Figure 7b is a graph showing the overpotential required for the catalyst for hydrogen generation reaction according to an example and comparative example of the present application.

Figure 7c is a graph showing the Tafel slope of a catalyst for hydrogen generation reaction according to an example and a comparative example of the present application.

Figure 7d is a graph showing the LSV polarization curve of a catalyst for hydrogen generation reaction according to an example and a comparative example of the present application.

Figure 7e is a graph showing the overpotential required for the catalyst for hydrogen generation reaction according to an example and comparative example of the present application.

Figure 7f is a graph showing the Tafel slope of a catalyst for hydrogen generation reaction according to an example and a comparative example of the present application.

Figure 7g is a graph showing the degree of hydrogen generation over time of the catalyst for hydrogen generation reaction according to an example and comparative example of the present application.

Figure 7h is a graph showing the degree of hydrogen generation over time by the catalyst for hydrogen generation reaction according to an embodiment of the present application.

8A and 8B are graphs showing the LSV polarization curve of a catalyst for hydrogen generation according to an embodiment of the present application.

Figure 9 is SEM images of NC, NiNi-SAD-NC, MnMn-SAD-NC, and MnNi-SAD-NC.

Figures 10 and 11 are STEM images of MnNi-SAD-NC.

Figure 12 shows the XPS analysis results of MnAg-SAD-NC.

Figure 13 shows the XPS analysis results of NiAg-SAD-NC.

Figure 14 shows the XPS analysis results of PdMn-SAD-NC.

Figure 15 shows the XPS analysis results of NiPd-SAD-NC.

Figure 16 shows the XPS analysis results of CoPd-SAD-NC.

Figure 17 shows the XPS analysis results of CuPd-SAD-NC.

Figure 18 shows the XPS analysis results of AgPd-SAD-NC.

Figure 19 shows the XPS analysis results of FeAu-SAD-NC.

Figure 20 shows the XPS analysis results of NiAu-SAD-NC.

Figure 21 shows the XPS analysis results of CoAu-SAD-NC.

Figure 22 is the XPS analysis result of CuAu-SAD-NC.

Figure 23 is the XPS analysis result of AgAu-SAD-NC.

Figure 24 shows the XPS analysis results of PdAu-SAD-NC.

Figure 25 shows the XPS analysis results of MnPt-SAD-NC.

Figure 26 is the XPS analysis result of NiPt-SAD-NC.

Figure 27 is the XPS analysis result of CoPt-SAD-NC.

Figure 28 shows the XPS analysis results of CuPt-SAD-NC.

Figure 29 shows the XPS analysis results of AgPt-SAD-NC.

Figure 30 shows the XPS analysis results of PdPt-SAD-NC.

Figure 31 shows the XPS analysis results of AuPt-SAD-NC.

Figure 32 is the XPS analysis result of NiRu-SAD-NC.

Figure 33 shows the XPS analysis results of CoRu-SAD-NC.

Figure 34 is the XPS analysis result of CuRu-SAD-NC.

Figure 35 is the XPS analysis result of AgRu-SAD-NC.

Figure 36 shows the XPS analysis results of PdRu-SAD-NC.

Figure 37 is the XPS analysis result of AuRu-SAD-NC.

Figure 38 shows the XPS analysis results of PtRu-SAD-NC.

Figure 39 shows the XPS analysis results of FeIr-SAD-NC.

Figure 40 shows the XPS analysis results of MnIr-SAD-NC.

Figure 41 shows the XPS analysis results of NiIr-SAD-NC.

Figure 42 is the XPS analysis result of CoIr-SAD-NC.

Figure 43 is the XPS analysis result of CuIr-SAD-NC.

Figure 44 shows the XPS analysis results of AgIr-SAD-NC.

Figure 45 is the XPS analysis result of PdIr-SAD-NC.

Figure 46 is the XPS analysis result of SnPt-SAD-NC.

Figure 47 is the XPS analysis result of SnRu-SAD-NC.

Figure 48 is the XPS analysis result of SnIr-SAD-NC.

Figure 49 is the XPS analysis result of InMn-SAD-NC.

Figure 50 shows the XPS analysis results of InNi-SAD-NC.

Figure 51 shows the XPS analysis results of InCo-SAD-NC.

Figure 52 is the XPS analysis result of InCu-SAD-NC.

Figure 53 shows the XPS analysis results of InAg-SAD-NC.

Figure 54 is the XPS analysis result of InPd-SAD-NC.

Figure 55 is the XPS analysis result of IrAu-SAD-NC.

Figure 56 is the XPS analysis result of IrPt-SAD-NC.

Figure 57 is the XPS analysis result of IrRu-SAD-NC.

Figure 58 is the XPS analysis result of MnSn-SAD-NC.

Figure 59 is the XPS analysis result of NiSn-SAD-NC.

Figure 60 shows the XPS analysis results of CoSn-SAD-NC.

Figure 61 is the XPS analysis result of CuSn-SAD-NC.

Figure 62 is the XPS analysis result of AgSn-SAD-NC.

Figure 63 is the XPS analysis result of PdSn-SAD-NC.

Figure 64 is the XPS analysis result of AuSn-SAD-NC.

Figure 65 is the XPS analysis result of BiRu-SAD-NC.

Figure 66 shows the XPS analysis results of BiIr-SAD-NC.

Figure 67 is the XPS analysis result of BiSn-SAD-NC.

Figure 68 is the XPS analysis result of BiIn-SAD-NC.

Figure 69 shows the XPS analysis results of PbMn-SAD-NC.

Figure 70 is the XPS analysis result of PbNi-SAD-NC.

Figure 71 is the XPS analysis result of PbCo-SAD-NC.

Figure 72 is the XPS analysis result of PbCu-SAD-NC.

Figure 73 is the XPS analysis result of PbAg-SAD-NC.

Figure 74 is the XPS analysis result of PbPd-SAD-NC.

Figure 75 is the XPS analysis result of PbAu-SAD-NC.

Figure 76 is the XPS analysis result of PbPt-SAD-NC.

Figure 77 is the XPS analysis result of InAu-SAD-NC.

Figure 78 is the XPS analysis result of InPt-SAD-NC.

Figure 79 is the XPS analysis result of InRu-SAD-NC.

Figure 80 shows the XPS analysis results of InIr-SAD-NC.

Figure 81 is the XPS analysis result of InSn-SAD-NC.

Figure 82 is the XPS analysis result of BiMn-SAD-NC.

Figure 83 is the XPS analysis result of BiNi-SAD-NC.

Figure 84 is the XPS analysis result of BiCo-SAD-NC.

Figure 85 is the XPS analysis result of BiCu-SAD-NC.

Figure 86 is the XPS analysis result of BiAg-SAD-NC.

Figure 87 is the XPS analysis result of BiPd-SAD-NC.

Figure 88 is the XPS analysis result of BiAu-SAD-NC.

Figure 89 shows the XPS analysis results of BiPt-SAD-NC.

Figure 90 shows the XPS analysis results of PbRu-SAD-NC.

Figure 91 shows the XPS analysis results of PbIr-SAD-NC.

Figure 92 is the XPS analysis result of PbSn-SAD-NC.

Figure 93 is the XPS analysis result of PbIn-SAD-NC.

Figure 94 is the XPS analysis result of PbBi-SAD-NC.

Figure 95 is the XPS analysis result of RhMn-SAD-NC.

Figure 96 is the XPS analysis result of RhNi-SAD-NC.

Figure 97 is the XPS analysis result of RhCo-SAD-NC.

Figure 98 is the XPS analysis result of RhCu-SAD-NC.

Figure 99 shows the XPS analysis results of RhAg-SAD-NC.

Figure 100 shows the XPS analysis results of RhPd-SAD-NC.

Figure 101 is the XPS analysis result of RhAu-SAD-NC.

Figure 102 is the XPS analysis result of RhPt-SAD-NC.

Figure 103 is the XPS analysis result of RhRu-SAD-NC.

Figure 104 shows the XPS analysis results of RhIr-SAD-NC.

Figure 105 is the XPS analysis result of RhSn-SAD-NC.

Figure 106 is the XPS analysis result of RhIn-SAD-NC.

Figure 107 is the XPS analysis result of MnNi-SAD-NC.

Figure 108 is the XPS analysis result of NiNi-SAD-NC.

Figure 109 is the XPS analysis result of MnMn-SAD-NC.

110 is a Fourier transform EXAFS (Extended X-ray. Absorption Fine Structure) spectrum graph and a am.

Figure 111 shows the XRD analysis results of FeNi-SAD-NC, FeCo-SAD-NC, FeMn-SAD-NC, CuNi-SAD-NC, and FeCu-SAD-NC.

Figure 112 is the XRD analysis results of MnCu-SAD-NC, CuNi-SAD-NC, MnNi-SAD-NC, MnCo-SAD-NC, and NiCo-SAD-NC.

Figure 113 shows the XRD analysis results of MnMn-SAD-NC, NiNi-SAD-NC, CoCu-SAD-NC, CoAg-SAD-NC, and FeAg-SAD-NC.

Figure 114 shows the XRD analysis results of CuAg-SAD-NC, MnAg-SAD-NC, NiAg-SAD-NC, PdFe-SAD-NC, and PdMn-SAD-NC.

Figure 115 is the XRD analysis results of PdNi-SAD-NC, PdCo-SAD-NC, PdCu-SAD-NC, PdAg-SAD-NC, and AuFe-SAD-NC.

Figure 116 shows the XRD analysis results of AuMn-SAD-NC, AuNi-SAD-NC, AuCo-SAD-NC, AuCu-SAD-NC, and AuAg-SAD-NC.

Figure 117 shows the XRD analysis results of AuPd-SAD-NC, PtFe-SAD-NC, PtMn-SAD-NC, PtNi-SAD-NC, and PtCo-SAD-NC.

Figure 118 shows the XRD analysis results of PtCu-SAD-NC, PtAg-SAD-NC, PtPd-SAD-NC, PtAu-SAD-NC, and RuFe-SAD-NC.

119 shows RuMn-SAD-NC, RuNi-SAD-NC, RuCo-SAD-NC, RuCu-SAD-NC, RuAg-SAD-NC, RuPd-SAD-NC, RuAu-SAD-NC, RuPt-SAD-NC , XRD analysis results of IrFe-SAD-NC and IrMn-SAD-NC.

120 shows IrNi-SAD-NC, IrCo-SAD-NC, IrCu-SAD-NC, IrAg-SAD-NC, IrPd-SAD-NC, IrAu-SAD-NC, IrPt-SAD-NC, IrRu-SAD-NC , XRD analysis results of SnFe-SAD-NC and SnMn-SAD-NC.

Figure 121 shows SnNi-SAD-NC, SnCo-SAD-NC, SnCu-SAD-NC, SnAg-SAD-NC, SnPd-SAD-NC, SnAu-SAD-NC, SnPt-SAD-NC, SnRu-SAD-NC , XRD analysis results of SnIr-SAD-NC and InFe-SAD-NC.

Figure 122 shows InMn-SAD-NC, InNi-SAD-NC, InCo-SAD-NC, InCu-SAD-NC, InAg-SAD-NC, InPd-SAD-NC, InAu-SAD-NC, InPt-SAD-NC , XRD analysis results of InRu-SAD-NC and InIr-SAD-NC.

Figure 123 shows InSn-SAD-NC, BiFe-SAD-NC, BiMn-SAD-NC, BiNi-SAD-NC, BiCo-SAD-NC, BiCu-SAD-NC, BiAg-SAD-NC, BiPd-SAD-NC , XRD analysis results of BiAu-SAD-NC and BiPt-SAD-NC.

Figure 124 shows BiRu-SAD-NC, BiIr-SAD-NC, BiSn-SAD-NC, BiIn-SAD-NC, PbFe-SAD-NC, PbMn-SAD-NC, PbNi-SAD-NC, PbCo-SAD-NC , XRD analysis results of PbCu-SAD-NC and PbAg-SAD-NC.

Figure 125 shows PbPd-SAD-NC, PbAu-SAD-NC, PbPt-SAD-NC, PbRu-SAD-NC, PbIr-SAD-NC, PbSn-SAD-NC, PbIn-SAD-NC, PbBi-SAD-NC , XRD analysis results of RhFe-SAD-NC and RhMn-SAD-NC.

Figure 126 shows RhNi-SAD-NC, RhCo-SAD-NC, RhCu-SAD-NC, RhAg-SAD-NC, RhPd-SAD-NC, RhAu-SAD-NC, RhPt-SAD-NC, RhRu-SAD-NC , RhIr-SAD-NC, RhSn-SAD-NC, RhIn-SAD-NC, RhBi-SAD-NC, and RhPb-SAD-NC.

Figure 127 is a graph to confirm the carbon dioxide reduction reaction activity of the MnNi-SAD-NC catalyst.

Figures 128 and 129 show the results of gas chromatography analysis of the product of the carbon dioxide reduction reaction using the MnNi-SAD-NC catalyst.

Figure 130 is a gas chromatography-mass spectrometry result for the product of a carbon dioxide reduction reaction using a MnNi-SAD-NC catalyst.

Figure 131 is a graph explaining the selectivity of product distribution of the carbon dioxide reduction reaction using the MnNi-SAD-NC catalyst.

Figure 132 is a graph to explain the long-term stability of the MnNi-SAD-NC catalyst.

Figure 133 is a ¹ H-NMR and ¹³ C-NMR graph for product analysis of carbon dioxide reduction reaction using a MnNi-SAD-NC catalyst.

Below, with reference to the attached drawings, embodiments of the present application will be described in detail so that those skilled in the art can easily implement them.

However, the present application may be implemented in various different forms and is not limited to the embodiments described herein. In order to clearly explain the present application in the drawings, parts that are not related to the description are omitted, and similar reference numerals are assigned to similar parts throughout the specification.

Throughout this specification, when a part is said to be “connected” to another part, this includes not only the case where it is “directly connected,” but also the case where it is “electrically connected” with another element in between. do.

Throughout this specification, when a member is said to be located “on”, “above”, “at the top”, “below”, “at the bottom”, or “at the bottom” of another member, this means that a member is located on another member. This includes not only cases where they are in contact, but also cases where another member exists between two members.

Throughout the specification of the present application, when a part "includes" a certain component, this means that it may further include other components rather than excluding other components unless specifically stated to the contrary.

As used herein, the terms “about,” “substantially,” and the like are used to mean at or close to a numerical value when manufacturing and material tolerances inherent in the stated meaning are presented, and to aid understanding of the present application. It is used to prevent unscrupulous infringers from unfairly exploiting disclosures in which precise or absolute figures are mentioned. Additionally, throughout the specification herein, “a step of” or “a step of” does not mean “a step for.”

Throughout this specification, the term "combination thereof" included in the Markushi format expression means a mixture or combination of one or more components selected from the group consisting of the components described in the Markushi format expression, It means including one or more selected from the group consisting of.

Throughout this specification, the description of “A and/or B” means “A or B, or A and B.”

Hereinafter, the catalyst of the present application, its production method, and the catalyst for hydrogen generation reaction including the same will be described in detail with reference to embodiments, examples, and drawings. However, the present application is not limited to these embodiments, examples, and drawings.

As a technical means for achieving the above-mentioned technical problem, the first aspect of the present application includes a nitrogen-doped carbon matrix; and a single atom metal bonded to nitrogen in the carbon matrix.

1A and 1B are schematic diagrams of a catalyst according to an embodiment of the present application. Specifically, Figure 1a is a schematic diagram of a catalyst comprising a single-atom dimer containing two types of metal atoms as a single-atom metal. As an example of a catalyst, Figure 1 shows a first single-atom metal (M ₁ ) and a second single atom metal. A catalyst containing SAD (single atom dimer) to which an atomic metal (M ₂ ) is bound is expressed. Additionally, Figure 1B relates to a catalyst comprising one type of single atom metal (eg, a first single atom metal, M ₁ ).

The single atom dimer includes a first single atom metal (M ₁ ) bonded to nitrogen in the carbon matrix, and a second single atom metal (M ₂ ) bonded to nitrogen that is not bonded to the first single atom metal (M ₁ ). ), and may include a combination of the first single-atomic metal (M ₁ ) and the second single-atomic metal (M ₁ ).

The first single atomic metal (M ₁ ) and the second single atomic metal (M ₂ ) are each selected from Ni, Co, Sc, Ti, V, Cr, Mn, Fe, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Ag, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, It may include any one of Dy, Ho, Er, Tm, Yb, and Lu.

According to one embodiment, the first single-atomic metal (M ₁ ) and the second single-atomic metal (M ₂ ) may be different from each other. In contrast, according to another embodiment, the first single-atomic metal (M ₁ ) and the second single-atomic metal (M ₂ ) may be the same.

For example, the single atom dimers include Fe-Ni, Fe-Co, Fe-Mn, Cu-Ni, Fe-Cu, Mn-Cu, Cu-Ni, Mn-Ni, Mn-Co, Ni-Co, Mn -Mn, Ni-Ni, Co-Cu, Co-Ag, Fe-Ag, Cu-Ag, Mn-Ag, Ni-Ag, Pd-Fe, Pd-Mn, Pd-Ni, Pd-Co, Pd-Cu , Pd-Ag, Au-Fe, Au-Mn, Au-Ni, Au-Co, Au-Cu, Au-Ag, Au-Pd, Pt-Fe, Pt-Mn, Pt-Ni, Pt-Co, Pt -Cu, Pt-Ag, Pt-Pd, Pt-Au, Ru-Fe, Ru-Mn, Ru-Ni, Ru-Co, Ru-Cu, Ru-Ag, Ru-Pd, Ru-Au, Ru-Pt , Ir-Fe, Ir-Mn, Ir-Ni, Ir-Co, Ir-Cu, Ir-Ag, Ir-Pd, Ir-Au, Ir-Pt, Ir-Ru, Sn-Fe, Sn-Mn, Sn -Ni, Sn-Co, Sn-Cu, Sn-Ag, Sn-Pd, Sn-Au, Sn-Pt, Sn-Ru, Sn-Ir, In-Fe, In-Mn, In-Ni, In-Co , In-Cu, In-Ag, In-Pd, In-Au, In-Pt, In-Ru, In-Ir, In-Sn, Bi-Fe, Bi-Mn, Bi-Ni, Bi-Co, Bi -Cu, Bi-Ag, Bi-Pd, Bi-Au, Bi-Pt, Bi-Ru, Bi-Ir, Bi-Sn, Bi-In, Pb-Fe, Pb-Mn, Pb-Ni, Pb-Co , Pb-Cu, Pb-Ag, Pb-Pd, Pb-Au, Pb-Pt, Pb-Ru, Pb-Ir, Pb-Sn, Pb-In, Pb-Bi, Rh-Fe, Rh-Mn, Rh -Ni, Rh-Co, Rh-Cu, Rh-Ag, Rh-Pd, Rh-Au, Rh-Pt, Rh-Ru, Rh-Ir, Rh-Sn, Rh-In, Rh-Bi, and Rh- Pb, etc. may be used.

In this regard, the synthesis of SADs based on different transition metals should be able to generate the desired dimer sites by varying the appropriate combination of metal precursors and metals used. In addition, the ratio of the precursor (for example, dopamine with a metal ion bound or poly dopamine with a metal ion bound) and dicandiamide may vary depending on the type of the transition metal, and when a heavy metal is used among the transition metals, stabilization More dicandiamide may be needed for this. In contrast, the synthesis of SAD based on the same transition metal can be produced by controlling the concentration of the metal precursor.

As will be described later, the catalyst can be used as a catalyst for hydrogen generation reaction.

Generally, platinum (Pt)-based catalysts are used as catalysts for hydrogen generation reactions, but their limited availability and high cost are required, which increases the unit cost of hydrogen generation. In order to reduce the unit cost of hydrogen generation, it is necessary to develop a catalyst that has similar or superior performance to platinum-based catalysts while using inexpensive materials.

The catalyst according to the present disclosure is a catalyst that can be included in a catalyst for a hydrogen evolution reaction, and includes a carbon matrix and a single atom metal bound on the carbon matrix. As will be described later, the catalyst can adsorb water molecules and reduce the energy required for the decomposition reaction of water molecules, thereby reducing the energy required for hydrogen generation.

According to one embodiment of the present application, the single atom metal may include one type of single atom metal or a single atom dimer of two types of single atom metals combined, but is not limited thereto.

The single-atomic metal according to the present application refers to one or two types of metal atoms, and the single-atomic metal is different from metal nanoparticles in which a plurality of metal atoms or ions of metal atoms are bonded.

The single-atom dimer means that two different metal atoms are metallically bonded to each other by electrons, and the number of metal atoms included is two. On the other hand, the metal nanoparticle is one in which a plurality of metal atoms are combined with a metal, and may have a relatively bulky structure because it contains a large number of metal atoms compared to a single atom dimer or a single type of single atom metal.

In other words, the single atomic metal according to the present application refers to one or two metal atoms, and when a plurality of metal atoms are combined, the metal atoms can expand into metal nanoparticles through a nanoparticle cluster.

Unlike metal nanoparticles in which only atoms located on the surface participate in the reaction, the single-atom metal may have high atom economy because it is composed of only one or two metal atoms that participate in the reaction.

According to one embodiment of the present application, the catalyst may include 1 to 20 parts by weight of the single atom metal based on 100 parts by weight of the carbon matrix, but is not limited thereto. The mass of single atomic metal included in the catalyst may be about 1% to about 20%, about 2% to about 20%, about 3% to about 20%, about 4% to about 20% of the mass of the carbon matrix, About 5% to about 20%, about 6% to about 20%, about 7% to about 20%, about 8% to about 20%, about 9% to about 20%, about 10% to about 20%, about 12 % to about 20%, about 14% to about 20%, about 16% to about 20%, about 18% to about 20%, about 1% to about 2%, about 1% to about 3%, about 1% to About 4%, about 1% to about 5%, about 1% to about 6%, about 1% to about 7%, about 1% to about 8%, about 1% to about 9%, about 1% to about 10 %, about 1% to about 12%, about 1% to about 14%, about 1% to about 16%, about 1% to about 18%, about 2% to about 18%, about 3% to about 16%, It may be about 4% to about 14%, about 5% to about 12%, about 6% to about 10%, about 7% to about 9%, or about 8%, but is not limited thereto.

The carbon matrix according to the present application, as will be described later, is formed by heat treatment of poly dopamine, and may have a three-dimensional structure or a two-dimensional structure. At this time, because the poly dopamine contains nitrogen, the carbon matrix may contain carbon and nitrogen.

According to one embodiment of the present application, the carbon matrix may be nitrogen-doped, but is not limited thereto.

According to one embodiment of the present application, the position of the single atom metal confined on the carbon matrix may be controlled by the doped nitrogen, but is not limited thereto.

According to one embodiment of the present application, the single atom metal may combine with the doped nitrogen, but is not limited thereto.

Specifically, when the carbon matrix contains nitrogen, the position of a single metal atom can be created at an optimal nitrogen position. However, if the carbon matrix does not contain nitrogen, metal ions may aggregate with each other to form clusters and nanoparticles of the carbon matrix.

Specifically, when the carbon matrix is doped with nitrogen, the nitrogen may bond to the single metal atom.

According to one embodiment of the present application, the single-atom metal may adsorb water molecules or reduce the decomposition reaction energy of the water molecules, but is not limited thereto.

According to one embodiment of the present application, the single atom metal is Ni, Co, Sc, Ti, V, Cr, Mn, Fe, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag , Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Ag, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu , and combinations thereof, but is not limited thereto.

For example, when the single-atom metal is a single-atom dimer containing Ni and Co, the Co site adsorbs a water molecule, and after the water is dissociated, the H* site moves to the Ni site to provide energy required for water dissociation. Barriers can be reduced.

Additionally, when the single atom metal is composed of a single metal atom containing either Ni or Co, adsorption and reduction of water may occur at the position of the single metal atom.

According to one embodiment of the present application, the single atom dimer may include a metal-metal bond of 0.2 nm to 0.4 nm, but is not limited thereto.

Additionally, the second aspect of the present application relates to a catalyst for hydrogen generation reaction, including the catalyst according to the first aspect.

With respect to the catalyst for hydrogen generation reaction according to the second aspect of the present application, detailed description of parts overlapping with the first aspect of the present application has been omitted. However, even if the description is omitted, the content described in the first aspect of the present application is the same as the first aspect of the present application. The same can be applied to both sides.

The catalyst for the hydrogen evolution reaction requires a low overpotential of 50 mV to 65 mV and 110 mV to 200 mV, respectively, to reach -10 mA/cm ² and -100 mA/cm ² , which is 20% Pt-C. Alternatively, it is similar to the overpotential requirements required for Pt single metal atom catalysts to reach -10 mA/cm ² and -100 mA/cm ² . However, a catalyst for hydrogen generation containing a catalyst containing metal nanoparticles instead of a single atom metal requires a higher overpotential compared to a catalyst for hydrogen generation reaction containing the catalyst according to the first aspect, which is due to the metal nano particle. This means that more energy is required for the hydrogen generation reaction when using particles.

According to one embodiment of the present application, the catalyst for hydrogen generation reaction may operate in a pH range of more than 0 and less than or equal to 14, but is not limited thereto. However, as the operating environment of the catalyst for hydrogen generation approaches neutrality (pH = 7), a problem occurs in which electrolyte conductivity may decrease.

In an acidic environment where the pH is less than 7, the water splitting reaction may begin with the adsorption of protons on the catalyst. However, in the case of a basic environment where the pH is greater than 7, the water decomposition reaction may begin with H ₂ O adsorption and dissociation reaction on the catalyst, so the catalyst has a reaction mechanism when located in an acidic environment and when located in a basic environment. This may be different.

The catalyst for hydrogen generation can generate hydrogen with high efficiency when supported in a 1 M KOH solution and a 0.5 M H ₂ SO ₄ solution.

Additionally, a third aspect of the present application relates to a method for producing a catalyst according to the first aspect, comprising mixing a precursor of a carbon matrix and a precursor of a single atom metal; self-polymerizing the carbon matrix precursor to form a carbon polymer; and mixing the carbon polymer and the nitrogen source and heat treating the catalyst.

Regarding the method for producing a catalyst according to the third aspect of the present application, detailed description of parts overlapping with the first aspect of the present application has been omitted. However, even if the description is omitted, the content described in the first aspect of the present application is the same as the second aspect of the present application. The same can be applied to the side.

FIG. 2 is a flowchart showing a method for producing a catalyst according to an embodiment of the present application, FIG. 3 is a schematic diagram showing a method for producing a catalyst according to an embodiment of the present application, and FIG. 4 is a flowchart showing a method for producing a catalyst containing metal nanoparticles. This is a schematic diagram showing the method. At this time, FIG. 3 shows a method for producing a catalyst containing a single-atom metal according to the first aspect, and FIG. 4 shows a method for producing a catalyst containing metal nanoparticles instead of a single-atom metal.

First, the precursor of the carbon matrix and the precursor of the single atom metal are mixed (S100).

According to one embodiment of the present application, the precursor of the carbon matrix and the precursor of the single atom metal may be mixed in a liquid phase, but are not limited thereto. At this time, the environment in which the two precursors are mixed may be inside a Tris buffer solution, but is not limited thereto.

According to one embodiment of the present application, the precursor of the carbon matrix may include dopamine, but is not limited thereto.

Dopamine refers to an organic compound of the catecholamine series with the molecular formula of C ₈ H ₁₁ NO ₂ . As will be described later, when the dopamine is injected into a Tris buffer solution and stirred at room temperature, it can be stirred on its own to form polydopamine.

According to one embodiment of the present application, the precursor of the single atom metal is Ni, Co, Sc, Ti, V, Cr, Mn, Fe, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd , Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Ag, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb , Lu, and combinations thereof may include ions of elements selected from the group, but are not limited thereto. At this time, the precursor of the single-atom metal may include one type of metal ion or two types of metal ions depending on the structure of the single-atom metal of the finished catalyst.

Subsequently, the precursor of the carbon matrix is self-polymerized to form a carbon polymer (S200).

According to one embodiment of the present application, the carbon polymer may include a precursor of the single-atom metal therein, but is not limited thereto.

When the carbon matrix precursor and the single-atom metal precursor are stirred at room temperature, the carbon matrix precursor may self-polymerize to become a carbon polymer. At this time, the precursor of the single-atom metal, that is, the metal ion, may combine with the carbon polymer.

According to one embodiment of the present application, the carbon polymer may include poly dopamine, but is not limited thereto.

In this regard, when the carbon polymer is poly dopamine, as can be seen in FIGS. 3 and 4, the metal ion of the single-atomic metal precursor can be combined with the nitrogen of the poly dopamine.

Next, the carbon polymer and nitrogen source are mixed and heat treated (S300).

The nitrogen source is a material for additionally supplying nitrogen to the carbon polymer. When the carbon polymer alone is heat treated without the nitrogen source, a catalyst containing metal nanoparticles can be produced as shown in FIG. 4. As described above, catalysts containing metal nanoparticles may have lower hydrogen generation efficiency due to lower atomic economy than catalysts containing single-atom metals.

According to one embodiment of the present application, the mass ratio of the carbon polymer and the nitrogen source may be 1:5 to 1:10, but is not limited thereto. Preferably, the mass ratio between the carbon polymer (poly dopamine bound to metal ions) and the nitrogen source (e.g. dicandiamide) may be 1:7.

According to one embodiment of the present application, by the heat treatment, the precursor of the single atom metal may become a single atom dimer of one type of single atom metal or two types of single atom metals combined, but is limited thereto. It doesn't work.

According to one embodiment of the present application, the carbon polymer may be a carbon matrix, but is not limited thereto.

According to one embodiment of the present application, the nitrogen source may include a material consisting of cyanoguanidine (dicyandiamide), guanidine, and combinations thereof, but is not limited thereto.

For example, when a carbon polymer containing poly dopamine to which Ni ions and Co ions are bonded is mixed with cyanoguanidine and heat treated, the poly dopamine may be converted into a nitrogen-doped two-dimensional carbon matrix. At this time, the number of nitrogens is increased by the cyanoguanidine compared to poly-dopamine, and the phenomenon of agglomeration of the Ni ions and Co ions is suppressed by the increased nitrogen position, resulting in a single atomic metal, that is, a Ni-Co dimer, instead of a metal nanoparticle. can be formed.

According to one embodiment of the present application, the heat treatment temperature may be 700°C to 900°C, but is not limited thereto.

Additionally, the catalyst according to the present disclosure can be used in a reaction that reduces carbon dioxide (CO ₂ ) to produce ethanol and acetone. Specifically, in the reaction of producing ethanol and acetone by reducing carbon dioxide using the catalyst according to the present application, a reaction as shown in <Formula 1> below occurs on the anode side, and a reaction as shown in <Formula 2> below occurs on the cathode side. It can happen.

8H ₂ O -> 4O ₂ + 16H ⁺ + 16e ^-

3CO ₂ + 16H ⁺ + 16e ^- -> CH ₃ COCH ₃ + 5H ₂ O

The present invention will be described in more detail through the following examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present application.

[Example 1]

[Example 1-1]: Formation of carbon polymer (Ni2+ Co2+@polydopamine)

1.21 g of Tris buffer was dissolved in 135 ml of DI water, and then 5 ml of a solution containing a metal salt was added. At this time, the concentration of the metal salt-containing solution is 2 mg/ml, and it contains Ni(NO ₃ ) ₂ ·6H ₂ O and Co(NO ₃ ) ₂ ·6H ₂ O in a ratio of 1:1.

Then, 70 mg of dopamine hydrochloride was quickly added, and the mixture was stirred with a magnet for 24 hours.

Subsequently, it was filtered, washed twice with DI water and ethanol, and dried at 60°C overnight to obtain Ni ²⁺ Co ²⁺ @polydopamine.

[Example 1-2]: Formation of catalyst (NiCo-SAD-NC)

The carbon polymer prepared by the method according to Example 1-1 and cyanoguanidine were mixed at a ratio of 1:7, and heat treated in a vacuum environment at 800°C for 2 hours to increase the temperature by 5°C per minute to obtain NiCo-SAD-NC. was formed.

[Example 2] to [Example 8]

The metal salt-containing solution in Example 1-1 was changed and prepared in the same manner as Example 1-2. At this time, the name of the catalyst for each example and the type and ratio of the metal salt contained in the metal salt-containing solution are shown in Table 1 below.

구분division	촉매 명칭Catalyst name	금속 염 종류Metal salt types	비율ratio
실시예2Example 2	NiCo-SAD-NC(1:2)NiCo-SAD-NC(1:2)	Ni(NO₃)₂·6H₂O 및 Co(NO₃)₂·6H₂ONi(NO ₃ ) ₂ ·6H ₂ O and Co(NO ₃ ) ₂ ·6H ₂ O	1:21:2
실시예3Example 3	NiCo-SAD-NC(2:1)NiCo-SAD-NC(2:1)	Ni(NO₃)₂·6H₂O 및 Co(NO₃)₂·6H₂ONi(NO ₃ ) ₂ ·6H ₂ O and Co(NO ₃ ) ₂ ·6H ₂ O	2:12:1
실시예4Example 4	Ni-SA-NCNi-SA-NC	Ni(NO₃)₂·6H₂ONi(NO ₃ ) ₂ ·6H ₂ O	--
실시예5Example 5	Co-SA-NCCo-SA-NC	Co(NO₃)₂·6H₂OCo(NO ₃ ) ₂ ·6H ₂ O	--
실시예6Example 6	CoFe-SAD-NCCoFe-SAD-NC	Co(NO₃)₂·6H₂O 및 Fe(NO₃)₃·9H₂OCo(NO ₃ ) ₂ ·6H ₂ O and Fe(NO ₃ ) ₃ ·9H ₂ O	1:11:1
실시예7Example 7	CoMn-SAD-NCCoMn-SAD-NC	Co(NO₃)₂·6H₂O 및 Mn(NO₃)₂·4H₂OCo(NO ₃ ) ₂ ·6H ₂ O and Mn(NO ₃ ) ₂ ·4H ₂ O	1:11:1
실시예8Example 8	Pt-SAPt-SA	H₂PtCl₆ _H2PtCl6 _{_}	--

In this regard, in Example 8, the mixing ratio of carbon polymer and cyanoguanidine is 1:20. [Example 9] and [Example 10]

It was prepared in the same manner as in Example 1, except that the metal salt-containing solution contained only one of Ni(NO ₃ ) ₂ ·6H ₂ O and Co(NO ₃ ) ₂ ·6H ₂ O. At this time, Example 9 is Ni-SA-NC, and Example 10 is Co-SA-NC.

[Comparative Example 1]: Formation of catalyst (NiCo-NP-NC) containing metal nanoparticles

The same steps as in Example 1 were performed, but heat treatment was performed without adding cyanoguanidine in the steps of Example 1-2.

[Comparative Example 2]: Carbon matrix (NC) formation

Pure polydopamine was prepared by following the same steps as in Example 1, but without including metal salts when forming the carbon polymer. Next, pure polydopamine was mixed with cyanoguanidine at a ratio of 1:7 and then heat treated.

[Experimental Example 1]

Figures 5a and 5b are graphs showing the It is an intensity profile and electron energy spectrum graph for site A, and Figure 5e is an intensity profile and electron energy spectrum graph for site B in Figure 5c,

Referring to Figures 5a and 5b, NiCo-NP-NC has peaks of (111), (200), and (220), which are peaks formed by NiCo metal nanoparticles. However, since NiCo-SAD-NC, Ni-SA-NC, and Co-SA-NC are similar to the XRD pattern of carbon matrix NC and no separate peaks are identified, the difference between metal nano atoms and single atom metal cannot be confirmed. You can.

In addition, referring to Figures 5c to 5e, isolated Ni or Co single atom metals as well as NiCo-SAD formed on NC can be confirmed, and dimers in which Ni and Co atoms are bonded can be identified through intensity profiles and electron energy loss spectra. You can check it.

Additionally, referring to Figure 5f, it can be seen that the spacing between Ni and Co atoms in SAD (single atom dimer) in which Ni and Co atoms are combined is 0.241 ± 0.024 nm.

Additionally, referring to Figure 5g, on NiCo-SAD-NC, N, Ni, and Co atoms are each localized and uniformly dispersed on the NC.

[Experimental Example 2]

Figure 6a is a XANES (X-ray absorption near edge structure) spectrum graph of a catalyst according to an example and a comparative example of the present application, and Figure 6b is a XANES spectrum graph of a catalyst according to an example and a comparative example of the present application. 6c is a Fourier transform EXAFS (Extended It is a graph, and FIG. 6e is a WT-EXAFS image of a catalyst according to an example and a comparative example of the present application.

6A and 6B, the K-only XANES spectra of Ni and Co of Ni-SA-NC, Co-SA-NC, NiCo-NP-NC, and NiCo-SAD-NC are, It was confirmed that it showed a similar trend to the spectrum. In this regard, compared to Ni metal and NiCo-NP-NC, a pre-edge peak around 8333.8 eV is observed in the Ni-edge XANES spectra of NiCo-SA-NC, Ni-SA-NC and standard nickel phthalocyanine (NiPC). It can be. In contrast to Ni-SA-NC, the perihelion and white line identified in the Ni K-edge XANES spectrum of NiCo-SAD-NC show positive changes, which means that the oxidation state of Ni in Ni-SAD-NC -This may mean higher than NC.

Meanwhile, in the case of Ni-SA-NC, it can be seen that a similar pre-peak appears at about 7705 eV, and it can be confirmed that the X-ray absorption Co center is centered in four coordinations (N or metal). At this time, the perihelion and white line features of the Co K-edge .

6C and 6D also display the Ni and Co K-only Fourier transform (FT) k3 weighted EXAFS spectra of NiCo-SAD-NC, Co-SA-NC, NiCo-NP-NC, Co, and Ni. will be. According to the Ni-K-edge FT-EXAFS spectra, the dominant peaks in the R space around 1.46 Ω and 1.53 Ω for Ni-SA-NC and NiCo-SAD-NC, respectively, can be assigned to Ni-N bonds. In this regard, the average Ni-N bond length is significantly shifted for NiCo-SAD-NC compared to Ni-SA-NC, which is consistent with the simultaneous appearance of a Ni-metal peak at 2.18 Ω that is not found in Ni-SA-NC. Together, the distorted D4h local symmetry of Ni atomic sites was confirmed.

In this regard, Ω can be measured in impedance spectroscopy using a Nyquist plot, and as Ω is smaller, the conductivity of the catalyst can be improved.

In addition, in Figure 6c, the peak value of NiCo-SAD-NC between 1 and 2 radial distance (Å) is larger than the peak value between 2 and 3 radial distance (Å), while the peak value of NiCo-NP-NC is between 1 and 2 radial distance (Å). It can be seen that the peak value between distance (Å) is smaller than the peak value between 2 and 3 Radial distance (Å).

Meanwhile, in the Co-K-EXAFS spectrum, the Co-N bond was stretched from 1.48 Ω (Co-SA-NC) to 1.56 Ω (NiCo-SAD-NC), indicating that the local symmetry of the center of Co-N was similar to that of Co-Ni bond 2. This means that it was distorted as it was formed additionally in Ω.

Referring to Figure 6e, the formation of NiCo dimer can be confirmed.

[Experimental Example 3]

The catalysts of Examples 1 to 8 and Comparative Examples 1 and 2 were used in the hydrogen evolution reaction.

Figure 7a is a graph showing the LSV polarization curve of the catalyst for hydrogen generation reaction according to an example and comparative example of the present application, and Figure 7b is a graph showing the overvoltage (over voltage) required for the catalyst for hydrogen generation reaction according to an example and comparative example of the present application. potential), and Figure 7c is a graph showing the Tafel slope of the catalyst for hydrogen generation reaction according to an example and comparative example of the present application, and Figure 7d is a graph showing the Tafel slope according to an example and comparative example of the present application. It is a graph showing the LSV polarization curve of the catalyst for hydrogen generation reaction, Figure 7e is a graph showing the overpotential required for the catalyst for hydrogen generation reaction according to an example and comparative example of the present application, and Figure 7f is an example of the present application It is a graph showing the Tafel slope of the catalyst for hydrogen generation reaction according to the Example and Comparative Example, and Figure 7g shows the degree of hydrogen generation over time of the catalyst for hydrogen generation reaction according to the Example and Comparative Example of the present application. This is the graph shown. Specifically, Figures 7a to 7c measure the degree of hydrogen generation in a basic solution of 1 M KOH, Figures 7d to 7f measure the degree of hydrogen generation in an acidic solution of 0.5 M H2SO4, and Figures 7g and 7h is a measure of the degree of hydrogen generation in both solutions. Additionally, the four graphs in Figure 7g are NiCo-SAD-NC (0.5 M H2SO4), NiCo-SAD-NC (1 M KOH), NiCo-NP-NC (0.5 M H2SO4), and NiCo-NP in order from the top. -NC stands for (1 M KOH).

Referring to FIGS. 7A to 7C, in a basic solution, a catalyst such as NiCo-SAD-NC has similar performance to a conventional Pt/C catalyst or a catalyst using a Pt monoatomic metal, and NiCo-NP-NC and It can be confirmed that it has superior performance compared to catalysts using metal nanoparticles.

In addition, referring to Figures 7d to 7f, even in acidic solutions, catalysts such as NiCo-SAD-NC have similar performance to conventional Pt/C catalysts or catalysts using Pt monoatomic metal, while NiCo-NP- It can be confirmed that it has superior performance compared to catalysts using metal nanoparticles such as NC.

Referring to Figure 7g, the NiCo-SAD-NC catalyst is superior to the NiCo-NP-NC catalyst in generating hydrogen generation reaction.

Additionally, referring to the graph inserted in FIG. 7g, the Faradaic efficiency is about 99% over about 1200 seconds, regardless of the pH of the supported solution, and about 180 μmol of hydrogen is produced in a 1 M KOH and 0.5 M H2SO4 solution. You can confirm that it has occurred.

Also, referring to FIG. 7h, the NiCo-SAD-NC catalyst according to the present application can have comparable water decomposition performance in both acidic and basic environments.

8A and 8B are graphs showing the LSV polarization curve of a catalyst for hydrogen generation according to an embodiment of the present application. Specifically, Figures 8a and 8b are graphs comparing three catalysts using Ni-SA-NC, Co-SA-NC, and NiCo-SAD-NC, where Figure 8a is in a 1 M KOH solution and Figure 8b is in a 1 M KOH solution. Measured in 0.5 M H2SO4 solution. Regardless of pH, catalysts using single-atom metals (Ni-SA-NC and Co-SA-NC) show lower HER performance compared to dimer catalysts (NiCo-SAD-NC).

In addition to the examples described above, catalysts were prepared using various metals. The catalyst preparation method was the same as the above-described examples, but a different type of metal precursor was used. Additionally, catalysts combining the same metal (e.g., NiNi, MnMn, etc.) were manufactured using a high concentration of metal precursor. Specifically, in the case of M ₁ M ₂ (e.g., NiCo), it was manufactured using a M ₁ precursor (Ni precursor) at a concentration of 0.1 wt% and an M ₂ precursor (Co precursor) at a concentration of 0.1 wt%, whereas M ₁ In the case of M ₁ (eg, NiNi), it was prepared using a M ₁ precursor (Ni precursor) at a concentration of 0.2 wt%. The types of metal components are shown in <Table 2> below.

금속metal	전구체precursor
MnMn	Mn(NO3)2. 4H2OMn(NO3)2. 4H2O
AgAg	AgNO₃ AgNO ₃
PdPD	Pd(NO3)2. x H2OPd(NO3)2. x H2O
CuCu	Cu(NO3)2. x H2OCu(NO3)2. x H2O
FeFe	Fe(NO3)3. 9H2OFe(NO3)3. 9H2O
AuAu	AuClAuCl
CoCo	Co(NO3)2. 6 H2OCo(NO3)2. 6 H2O
PbPb	Pb(NO3)2Pb(NO3)2
PtPt	[Pt(NH3)4] (NO3)2[Pt(NH3)4] (NO3)2
RuRu	RuCl3. x H2ORuCl3. x H2O
IrIR	IrCl3. x H2OIrCl3. x H2O
SnSn	SnCl2SnCl2
InIn	In(NO3)3. x H2OIn(NO3)3. x H2O
BiBi	Bi(NO3)3. 5 H2OBi(NO3)3. 5 H2O
RhRh	Rh(NO3)3. x H2ORh(NO3)3. x H2O

Figure 9 is SEM images of NC, NiNi-SAD-NC, MnMn-SAD-NC, and MnNi-SAD-NC.

Referring to Figure 9(a), it shows the SEM (Scanning Electron Microscope) image of NC, Figure 9(b) shows the SEM image of NiNi-SAD-NC, and Figure 9(c) shows it. Shows the SEM image of MnMn-SAD-NC, and referring to (d) in Figure 9 shows the SEM image of MnNi-SAD-NC.

As can be seen from (a) to (d) of FIG. 9, it can be confirmed that a single-atom dimer in which the first and second single-atom metals are the same (NiNi, MnMn) can also be produced.

Figures 10 and 11 are STEM images of MnNi-SAD-NC.

Referring to Figures 10 and 11, they show STEM (Scanning Transmission Electron Microscopy) images of MnNi-SAD-NC.

Specifically, Figure 10 shows a case where the total content of the Mn precursor and Ni precursor is 0.2 wt% or less, and Figure 11 shows a case where the total content of the Mn precursor and Ni precursor is more than 0.2 wt%. As can be seen in Figure 10, when it is less than 0.2 wt%, it exists in the form of SAD, whereas when it exceeds 0.2 wt%, it exists in the form of a cluster.

Figures 12 to 109 show the results of XPS analysis to confirm various combinations of single-atom dimers, and it can be confirmed that various combinations of metals can be used as single-atom dimers.

In addition, it can be seen from Figures 12 to 109 that no chemical bond is observed between the single-atom metal and carbon as a result of XPS analysis, and compared to NC and single-atom-NC, FeNi-SAD-NC and FeCo-SAD-NC , FeMn-SAD-NC, CuNi-SAD-NC, FeCu-SAD-NC, MnCu-SAD-NC, CuNi-SAD-NC, MnNi-SAD-NC, MnCo-SAD-NC, NiCo-SAD-NC, MnMn -SAD-NC, NiNi-SAD-NC, CoCo-SAD-NC, and especially MnNi-SAD-NC, the N 1s You can check it.

Additionally, both metal atoms, including but not limited to Mn, Fe, Co, Ni, Cu, Ag, Pd, Ru, Rh, Ir, Pt, Au, Sn, In, Bi, Pb-NC, are present in the 2p XPS spectrum. It can be seen that one shows 2p ^3/2 and 2 ^p1/2 peak characteristics.

Additionally, it can be seen that the binding energy for a metal atom in one of the samples shifts to positive after N is introduced to confine a single atom site, indicating the formation of an -N bond.

However, after forming the dimer site, one of the 2p ^3/2 While showing a change, one of the 2p ^3/2 .

Figure 12 shows the XPS analysis results of MnAg-SAD-NC.

Figure 13 shows the XPS analysis results of NiAg-SAD-NC.

Figure 14 shows the XPS analysis results of PdMn-SAD-NC.

Figure 15 shows the XPS analysis results of NiPd-SAD-NC.

Figure 16 shows the XPS analysis results of CoPd-SAD-NC.

Figure 17 shows the XPS analysis results of CuPd-SAD-NC.

Figure 18 shows the XPS analysis results of AgPd-SAD-NC.

Figure 19 shows the XPS analysis results of FeAu-SAD-NC.

Figure 20 shows the XPS analysis results of NiAu-SAD-NC.

Figure 21 shows the XPS analysis results of CoAu-SAD-NC.

Figure 22 is the XPS analysis result of CuAu-SAD-NC.

Figure 23 is the XPS analysis result of AgAu-SAD-NC.

Figure 24 shows the XPS analysis results of PdAu-SAD-NC.

Figure 25 is the XPS analysis result of MnPt-SAD-NC.

Figure 26 is the XPS analysis result of NiPt-SAD-NC.

Figure 27 is the XPS analysis result of CoPt-SAD-NC.

Figure 28 shows the XPS analysis results of CuPt-SAD-NC.

Figure 29 shows the XPS analysis results of AgPt-SAD-NC.

Figure 30 shows the XPS analysis results of PdPt-SAD-NC.

Figure 31 shows the XPS analysis results of AuPt-SAD-NC.

Figure 32 is the XPS analysis result of NiRu-SAD-NC.

Figure 33 shows the XPS analysis results of CoRu-SAD-NC.

Figure 34 is the XPS analysis result of CuRu-SAD-NC.

Figure 35 is the XPS analysis result of AgRu-SAD-NC.

Figure 36 shows the XPS analysis results of PdRu-SAD-NC.

Figure 37 is the XPS analysis result of AuRu-SAD-NC.

Figure 38 shows the XPS analysis results of PtRu-SAD-NC.

Figure 39 shows the XPS analysis results of FeIr-SAD-NC.

Figure 40 shows the XPS analysis results of MnIr-SAD-NC.

Figure 41 shows the XPS analysis results of NiIr-SAD-NC.

Figure 42 is the XPS analysis result of CoIr-SAD-NC.

Figure 43 is the XPS analysis result of CuIr-SAD-NC.

Figure 44 shows the XPS analysis results of AgIr-SAD-NC.

Figure 45 is the XPS analysis result of PdIr-SAD-NC.

Figure 46 is the XPS analysis result of SnPt-SAD-NC.

Figure 47 is the XPS analysis result of SnRu-SAD-NC.

Figure 48 is the XPS analysis result of SnIr-SAD-NC.

Figure 49 is the XPS analysis result of InMn-SAD-NC.

Figure 50 shows the XPS analysis results of InNi-SAD-NC.

Figure 51 shows the XPS analysis results of InCo-SAD-NC.

Figure 52 is the XPS analysis result of InCu-SAD-NC.

Figure 53 shows the XPS analysis results of InAg-SAD-NC.

Figure 54 is the XPS analysis result of InPd-SAD-NC.

Figure 55 is the XPS analysis result of IrAu-SAD-NC.

Figure 56 is the XPS analysis result of IrPt-SAD-NC.

Figure 57 is the XPS analysis result of IrRu-SAD-NC.

Figure 58 is the XPS analysis result of MnSn-SAD-NC.

Figure 59 is the XPS analysis result of NiSn-SAD-NC.

Figure 60 shows the XPS analysis results of CoSn-SAD-NC.

Figure 61 is the XPS analysis result of CuSn-SAD-NC.

Figure 62 is the XPS analysis result of AgSn-SAD-NC.

Figure 63 is the XPS analysis result of PdSn-SAD-NC.

Figure 64 is the XPS analysis result of AuSn-SAD-NC.

Figure 65 is the XPS analysis result of BiRu-SAD-NC.

Figure 66 shows the XPS analysis results of BiIr-SAD-NC.

Figure 67 is the XPS analysis result of BiSn-SAD-NC.

Figure 68 is the XPS analysis result of BiIn-SAD-NC.

Figure 69 shows the XPS analysis results of PbMn-SAD-NC.

Figure 70 is the XPS analysis result of PbNi-SAD-NC.

Figure 71 is the XPS analysis result of PbCo-SAD-NC.

Figure 72 is the XPS analysis result of PbCu-SAD-NC.

Figure 73 is the XPS analysis result of PbAg-SAD-NC.

Figure 74 is the XPS analysis result of PbPd-SAD-NC.

Figure 75 is the XPS analysis result of PbAu-SAD-NC.

Figure 76 is the XPS analysis result of PbPt-SAD-NC.

Figure 77 is the XPS analysis result of InAu-SAD-NC.

Figure 78 is the XPS analysis result of InPt-SAD-NC.

Figure 79 is the XPS analysis result of InRu-SAD-NC.

Figure 80 shows the XPS analysis results of InIr-SAD-NC.

Figure 81 is the XPS analysis result of InSn-SAD-NC.

Figure 82 is the XPS analysis result of BiMn-SAD-NC.

Figure 83 is the XPS analysis result of BiNi-SAD-NC.

Figure 84 is the XPS analysis result of BiCo-SAD-NC.

Figure 85 is the XPS analysis result of BiCu-SAD-NC.

Figure 86 is the XPS analysis result of BiAg-SAD-NC.

Figure 87 is the XPS analysis result of BiPd-SAD-NC.

Figure 88 is the XPS analysis result of BiAu-SAD-NC.

Figure 89 shows the XPS analysis results of BiPt-SAD-NC.

Figure 90 shows the XPS analysis results of PbRu-SAD-NC.

Figure 91 shows the XPS analysis results of PbIr-SAD-NC.

Figure 92 is the XPS analysis result of PbSn-SAD-NC.

Figure 93 is the XPS analysis result of PbIn-SAD-NC.

Figure 94 is the XPS analysis result of PbBi-SAD-NC.

Figure 95 is the XPS analysis result of RhMn-SAD-NC.

Figure 96 is the XPS analysis result of RhNi-SAD-NC.

Figure 97 is the XPS analysis result of RhCo-SAD-NC.

Figure 98 is the XPS analysis result of RhCu-SAD-NC.

Figure 99 shows the XPS analysis results of RhAg-SAD-NC.

Figure 100 shows the XPS analysis results of RhPd-SAD-NC.

Figure 101 is the XPS analysis result of RhAu-SAD-NC.

Figure 102 is the XPS analysis result of RhPt-SAD-NC.

Figure 103 is the XPS analysis result of RhRu-SAD-NC.

Figure 104 shows the XPS analysis results of RhIr-SAD-NC.

Figure 105 is the XPS analysis result of RhSn-SAD-NC.

Figure 106 is the XPS analysis result of RhIn-SAD-NC.

Figure 107 is the XPS analysis result of MnNi-SAD-NC.

Figure 108 is the XPS analysis result of NiNi-SAD-NC.

Figure 109 is the XPS analysis result of MnMn-SAD-NC.

It shows that the overall XANES spectra of Ni and Mn K-edge XANES spectra show similar trends as the corresponding XPS spectral functions. It can be seen that a free edge peak of approximately 8333.8 eV is observed in the Ni K-edge XANES spectrum. Additionally, it can be confirmed that the free edge peak around 6545.4 eV is observed in the Mn K-edge XANES spectrum.

Figures 111 to 126 show the results of XRD analysis to confirm various combinations of single-atom dimers, and it can be confirmed that various combinations of metals can be used as single-atom dimers. In the detailed drawing description below, the order of each single atom dimer indicates the order from bottom to top.

Referring to Figure 127, the linear voltage measured with the H-cell in 0.5M sodium bicarbonate solution saturated with argon (Ar) and carbon dioxide (CO2) relative to the reference potential of the reversible hydrogen electrode (RHE) Indicates a scan voltammogram (linear scan voltammogram). Through the CV curve, it can be seen that it shows clear activity for CO ₂ RR (CO ₂ reduction reaction) in the potential range.

Referring to Figure 128, the electrolyte system was continuously purged with CO ₂ while the chronopositron measurements were performed in a gas chromatograph (GC) system. The gaseous products resulting from CO ₂ reduction were transferred to an attached 0.6L Teldar® PLV gas sampling bag using CO ₂ as a carrier gas. The gas bag was then sealed and extracted using the tested 2 mL sample. Through gas chromatography (GC) results, it can be confirmed that acetone is included in the product of the carbon dioxide reduction reaction. Additionally, through Figure 129, it can be confirmed that ethanol is included in the product of the carbon dioxide reduction reaction.

Referring to Figure 130, gas chromatography-mass spectrometry (GC-MS) was used to identify the products of the CO2RR reaction using one of the above catalysts. Chronoamphetomics measurements were performed in a GC system with the electrolyte system continuously purged with CO ₂ . CO ₂ was used as a carrier gas to direct the gaseous products from CO ₂ reduction into an attached 0.6L Teldar® PLV gas sampling bag. The gas bag was then sealed and extracted using the tested 2 mL sample. Through GC-MS results, it can be confirmed that acetone is included in the product of the carbon dioxide reduction reaction.

Referring to Figure 131, the selectivity of product distribution as a function of polarization potential is shown using the MnNi-SAD-NC catalyst. It can be seen that the selectivity to acetone at -0.75 V is about 90%. This shows product selectivity for various metal concentrations. In addition, it can be seen that as the loading amount increases, the acetone formation rate also accelerates.

Referring to Figure 132, the long-term stability of the MnNi-SAD-NC catalyst for CO ₂ RR, NRR, urea synthesis, and OER/HER is shown. It can be seen that CO ₂ reactant conversion and its activity remain stable for 10 days.

Referring to Figure 133, ¹ H-NMR and ¹³ C-NMR analyzes were used to identify acetone in the product of the MnNi-SAD-NC catalyzed carbon dioxide reduction reaction, calibrated with an internal standard of the chemical of known concentration. . For NMR analysis, 200 μl of electrolyte sample was added to 1.6 ml CDCl ₃ .

The description of the present application described above is for illustrative purposes, and those skilled in the art will understand that the present application can be easily modified into other specific forms without changing its technical idea or essential features. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as unitary may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present application is indicated by the claims described below rather than the detailed description above, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present application.

The catalyst and its manufacturing method according to embodiments of the present invention can be applied to industrial fields where electrochemical reactions occur.

Claims

Nitrogen-doped carbon matrix; and

A catalyst comprising a single atom metal bonded to nitrogen in the carbon matrix.
According to claim 1,

The single atom metal is a catalyst comprising one type of single atom metal or a single atom dimer in which two types of single atom metals are combined.
According to claim 2,

The single atom dimer is,

a first single atom metal bonded to nitrogen in the carbon matrix, and a second single atom metal bonded to nitrogen that is not bonded to the first single atom metal,

A catalyst comprising the first single atom metal and the second single atom metal combined.
According to claim 1,

and wherein the first single atom metal and the second single atom metal are different from each other.
According to claim 1,

and wherein the first single atomic metal and the second single atomic metal include the same thing.
According to claim 1,

As a result of Fourier transform EXAFS (Extended
According to claim 1,

A catalyst comprising: no chemical bond between the single atom metal and carbon is observed as a result of XPS analysis.
According to claim 1,

The single atomic metals include Ni, Co, Sc, Ti, V, Cr, Mn, Fe, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W , Re, Os, Ir, Pt, Au, Ag, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and combinations thereof. A catalyst comprising an atom selected from the group.
According to claim 1,

A catalyst, including one used in a reaction to reduce water (H 2 O) to produce hydrogen (H 2 ).
According to claim 1,

Catalysts, including those used in reactions that reduce carbon dioxide (CO 2 ) to produce ethanol and acetone.
According to claim 1,

A catalyst, including one used in a reaction to reduce nitrogen (N 2 ) to produce ammonia.
A base structure in which some of the carbon forming the carbon matrix is replaced with nitrogen; and

Includes a single atom dimer bonded to nitrogen in the base structure,

The single atom dimer includes a first single atom metal bonded to nitrogen in the base structure, and a second single atom metal bonded to nitrogen that is not bonded to the first single atom metal,

A catalyst comprising the first single atom metal and the second single atom metal combined.
mixing a precursor of a carbon matrix and a precursor of a single atom metal;

self-polymerizing the carbon matrix precursor to form a carbon polymer; and

A method for producing a catalyst, comprising mixing the carbon polymer and a nitrogen source and heat treating.
According to claim 13,

A method of producing a catalyst, wherein the carbon polymer includes therein a precursor of the single atom metal.
According to claim 13,

By the heat treatment, the precursor of the single atom metal becomes a single atom dimer of one type of single atom metal or two types of single atom metals, and the carbon polymer becomes a carbon matrix. Preparation of a catalyst method.
According to claim 13,

A method for producing a catalyst, wherein the precursor of the carbon matrix includes dopamine, and the carbon polymer includes poly dopamine.