Mxene electrochemical catalyst

Abstract

The present application relates to: a MXene electrochemical catalyst having a -OOH group introduced to the surface thereof; a method for preparing same; and an oxygen evolution reaction system comprising same. The MXene electrochemical catalyst according to embodiments described in the present application is characterized in that ion diffusion, active site exposure, and catalytic efficiency have been improved through surface functionalization defect engineering and interlayer spacing control via hydrothermal processing.

Description

MXene electrochemical catalyst

[0001] The present invention relates to a MXene electrochemical catalyst having -OOH introduced on its surface, a method for manufacturing the same, and an oxygen evolution reaction system comprising the same.

[0002] MXene is a two-dimensional nanomaterial consisting of alternating metal and carbon layers, and its properties vary depending on the type and amount of molecules covering the surface. Generally, M n+1 X n T x It is expressed as (n=1 to 3), where M is a transition metal, X is carbon or nitrogen, and T x represents the terminal surface functional group (-F, -O, or -OH) of the MXene. Ti3C2T, the most widely studied MXene x The conductivity level of Ti3C2T was observed to surpass that of other solution-processed 2D materials, regardless of the presence of functional groups within the MXene particle interlayer. This high conductivity makes Ti3C2T suitable for a wide range of possible applications in electronic and energy devices. x　 This led to the spread of research on MXene.

[0003] However, the electrochemical performance of MXene is limited by surface instability, low active site availability, and oxidation sensitivity, and when used as a catalyst for electrochemical reactions, there is a problem in that reaction activity is inhibited due to slow intermediate adsorption and inefficient reaction pathways.

[0004] [Prior Art Literature]

[0005] [Patent Literature]

[0006] Republic of Korea Published Patent Application No. 2024-0083831.

[0007] The present invention aims to provide a MXene electrochemical catalyst having -OOH introduced on its surface, a method for manufacturing the same, and an oxygen evolution reaction system comprising the same.

[0008] However, the problems that this invention seeks to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description below.

[0009] The first aspect of the present invention provides a MXene electrochemical catalyst comprising a MXene represented by the following chemical formula 1:

[0010] [Chemical Formula 1]

[0011] M n+1 X n T x ,

[0012] In the above chemical formula 1, M is a transition metal selected from elements belonging to groups 3 to 6 of the periodic table, X is C, N, or a combination thereof, and T x is one containing a (oxy)hydroxide group (-OOH), and n is 1, 2, or 3.

[0013] A second aspect of the present invention provides a method for preparing a MXene electrochemical catalyst, comprising: hydrothermally treating pristine MXene to obtain reduced MXene; and electroactivating the reduced MXene using an alkaline solution to obtain MXene represented by Formula 1.

[0014] A third aspect of the present invention provides an oxygen evolution reaction system comprising a MXene electrochemical catalyst according to a first aspect.

[0015] The MXene electrochemical catalyst according to the embodiments of the present invention is characterized by improved ion diffusion, active site exposure, and catalytic efficiency through surface functionalization defect engineering and interlayer spacing control via hydrothermal treatment.

[0016] The MXene electrochemical catalyst according to the embodiments of the present invention can dynamically control the number of -OOH species on the MXene surface through electroactivation to induce a more efficient transition of the OER pathway (Oxide Pathway Mechanism (OPM)).

[0017] An oxygen evolution reaction system comprising a MXene electrochemical catalyst according to the embodiments of the present invention, unlike conventional systems that focus on the adsorbate evolution mechanism (AEM) and the lattice oxygen mechanism (LOM), can enable direct OO bonding without the intervention of OOH intermediates or lattice oxygen by utilizing the Oxide Pathway Mechanism (OPM).

[0018] FIGS. 1a to 1d, in one embodiment of the present invention, comprises: (a) a schematic diagram of the synthesis process of an rTi3C2 electrocatalyst; (b) X-ray diffraction (XRD) patterns and enlarged XRD patterns of Ti3Al2C2, Ti3C2, rTi3C2, and Ex-rTi3C2 catalysts; and (c) a low wavenumber region (200 cm⁻¹) of Ti3C2, rTi3C2, and Ex-rTi3C2. -1 to 8800 cm -1 ) and (d) high wavenumber region (1,000 cm -1 to 1,800 cm -1 This shows the Raman spectrum of ).

[0019] FIG. 2 is a schematic diagram of surface-treated rTi3C2 (rTi3C2-T) in one embodiment of the present invention.

[0020] FIGS. 3a to 3c show the electrocatalytic OER performance of Ti3C2, Ti3C2-T, rTi3C2, rTi3C2-T, Ex-rTi3C2, and Ex-rTi3C2-T catalysts evaluated in a 0.5 M H2SO4 electrolyte in one embodiment of the present invention, comprising (a) a linear sweep voltammetry (LSV) curve, and (b) 10 mA cm⁻¹ -2 (c) shows the corresponding overvoltage at (a) and the Tafel curve derived from the LSV curve of (a).

[0021] Figures 4a to 4c show the modified MXene observed during the OER activation process, where (a) the intensity peaks of Ti3C2O(OH) and Ti3C2(OH)2 were normalized with respect to the intensity peak of Ti3C2O2, and (b) SO4 in the Raman spectrum. 2- band (960 cm) -2 ) and HSO4 - band (1040 cm) -1 (c) The stability of the modified MXene during OER measurement was confirmed through the observation results of ) and the analysis of the corresponding intensity peaks.

[0022] FIG. 5a and b show the results of the analysis of OER intermediates of rTi3C2 and rTi3C2-T electrocatalysts in an electrolyte containing (a) 0.5 M TMAOH and (b) 0.5 M MeOH in one embodiment of the present invention.

[0023] Hereinafter, embodiments and examples of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments and examples described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals.

[0024] Throughout this specification, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "electrically connected" with other elements interposed between them.

[0025] Throughout this specification, when a component is described as being located "on" another component, this includes not only cases where a component is in contact with another component, but also cases where another component exists between the two components.

[0026] Throughout this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0027] Terms of degree used in this specification, such as “about,” “substantially,” etc., are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the stated meaning, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosure in which precise or absolute values ​​are mentioned to aid in understanding the invention.

[0028] The terms “step of” or “step of” as used throughout this specification do not mean “step for”.

[0029] Throughout this specification, the term “combination(s) of these” included in the Markush-type expression means one or more mixtures or combinations selected from the group consisting of the components described in the Markush-type expression, and means including one or more selected from the group consisting of said components.

[0030] Throughout this specification, the description of "A and / or B" means "A or B, or A and B".

[0031] Embodiments of the present invention have been described in detail below, but the present invention may not be limited thereto.

[0032] The first aspect of the present invention provides a MXene electrochemical catalyst comprising a MXene represented by the following chemical formula 1:

[0033] [Chemical Formula 1]

[0034] M n+1 X n T x ,

[0035] In the above chemical formula 1, M is a transition metal selected from elements belonging to groups 3 to 6 of the periodic table, X is C, N, or a combination thereof, and T x is one containing a (oxy)hydroxide group (-OOH), and n is 1, 2, or 3.

[0036] In one embodiment of the present invention, M may be a transition metal selected from Sc, Y, Lu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W.

[0037] In one embodiment of the present invention, the MXene may comprise Ti2C, Ti3C2, Ti4N3, V4C3, Nb4C3, Ta4C3, Ti3N2, Zr3C2, Ti3(CN), V2C, Zr2C, Cr2C, Hf2N, Hf2C, Zr2N, V2N, Nb2C, Ta2C, W2C, Cr2N, or Mo2C.

[0038] In one embodiment of the present invention, the above T x It may additionally include one or more selected from oxo groups (=O) and hydroxide groups (-OH), but is not limited thereto.

[0039] In one embodiment of the present invention, the MXene electrochemical catalyst may have an exfoliated layered structure, but may not be limited thereto.

[0040] In one embodiment of the present invention, the thickness of one layer of the MXene electrochemical catalyst may be about 1 nm to about 100 nm, but is not limited thereto.

[0041] In one embodiment of the present invention, the MXene electrochemical catalyst may be used in an oxygen evolution reaction.

[0042] A second aspect of the present invention provides a method for preparing a MXene electrochemical catalyst, comprising: hydrothermally treating pristine MXene to obtain a reduced MXene; and electroactivating the reduced MXene using an alkaline solution to obtain a MXene represented by the following chemical formula 1:

[0043] [Chemical Formula 1]

[0044] M n+1 X n T x ,

[0045] In the above chemical formula 1, M is a transition metal selected from elements belonging to groups 3 to 6 of the periodic table, X is C, N, or a combination thereof, and T x is one containing a (oxy)hydroxide group (-OOH), and n is 1, 2, or 3.

[0046] Detailed explanations have been omitted for parts that overlap with the first aspect of the present invention, but the content described in the first aspect of the present invention may be applied in the same way even if such explanations are omitted in the second aspect of the present invention.

[0047] In one embodiment of the present invention, the sequence processing may be performed for about 2 hours to about 5 hours, about 2 hours to about 4 hours, or about 3 hours, but may not be limited thereto.

[0048] In one embodiment of the present invention, the hydrothermal treatment may be performed in a temperature range of about 150°C to about 200°C, about 150°C to about 190°C, about 150°C to about 180°C, about 160°C to about 200°C, about 160°C to about 190°C, about 160°C to about 180°C, about 170°C to about 200°C, about 170°C to about 190°C, or about 170°C to about 180°C, but is not limited thereto.

[0049] In one embodiment of the present invention, the alkaline solution may comprise one or more selected from KOH solution, NaOH solution, LiOH solution, and CsOH solution, but is not limited thereto.

[0050] In one embodiment of the present invention, the concentration of the alkaline solution is about 0.01 M to about 1 M, about 0.01 M to about 0.5 M, about 0.01 M to about 0.3 M, about 0.01 M to about 0.1 M, about 0.05 M to about 1 M, about 0.05 M to about 0.5 M, about 0.05 M to about 0.3 M, about 0.05 M to about 0.1 M, about 0.07 M to about 1 M, about 0.07 M to about 0.5 M, about 0.07 M to about 0.3 M, about 0.07 M to about 0.1 M, about 0.09 M to about 1 M, about 0.09 M to about 0.5 M, about 0.09 M to about 0.3 M, about 0.09 M to about 0.1 M, It may be about 0.1 M to about 1 M, about 0.1 M to about 0.5 M, or about 0.1 M to about 0.3 M, but is not limited thereto.

[0051] In one embodiment of the present invention, the layer of MXene may be exfoliated through the hydrothermal treatment to form an exfoliated layered structure, and at the same time, the MXene may be reduced.

[0052] In one embodiment of the present invention, the surface area may be increased by exfoliating the layer of MXene, thereby improving electrochemical activity.

[0053] In one embodiment of the present invention, oxygen vacancies are introduced by reducing the MXene, thereby improving electron conductivity and intermediate adsorption capacity during electrochemical reactions.

[0054] In one embodiment of the present invention, the electroactivation is approximately -0.1 V RHE up to -0.4 V RHEIt may be performed by applying a potential of a range in about 1 to about 40 cycles, but is not limited thereto.

[0055] In one embodiment of the present invention, a (oxy)hydroxide group (-OOH) can be introduced to the surface of the MXene electrochemical catalyst through the electroactivation.

[0056] In one embodiment of the present invention, the -OOH of the MXene electrochemical catalyst controls the oxygen evolution reaction pathway, thereby enabling a pathway transition from the adsorbate evolution mechanism (AEM) and / or lattice oxygen mechanism (LOM) to the oxide pathway mechanism (OPM). More specifically, the oxygen evolution reaction pathway may transition from AEM to OPM in a mixed state of AEM and LOM.

[0057] An oxygen evolution reaction system comprising a MXene electrochemical catalyst according to the embodiments of the present invention can enable direct OO bonding without the intervention of OOH intermediates or lattice oxygen by utilizing an Oxide Pathway Mechanism (OPM), unlike conventional systems that focus on the adsorbate evolution mechanism (AEM) and the lattice oxygen mechanism (LOM).

[0058] A third aspect of the present invention provides an oxygen evolution reaction system comprising a MXene electrochemical catalyst according to a first aspect.

[0059] Detailed descriptions of parts that overlap with the first and second aspects of the present invention have been omitted, but the descriptions of the first and second aspects of the present invention may be applied in the same way even if such descriptions are omitted in the third aspect of the present invention.

[0060] In one embodiment of the present invention, the oxygen generation reaction system may be a water electrolysis system, a metal-air battery system, or a carbon dioxide electrolysis (oxidation) system, but may not be limited thereto.

[0061] In one embodiment of the present invention, the water electrolysis system may comprise, but is not limited to, an anode for an oxygen evolution reaction comprising a MXene electrochemical catalyst according to the first aspect, a conductive material, and a binder; water comprising an alkaline electrolyte; and a cathode immersed in said water.

[0062] In one embodiment of the present invention, the oxygen evolution reaction pathway of the oxygen evolution reaction system may be an oxide pathway mechanism (OPM), but is not limited thereto.

[0063] The present invention will be explained in more detail below using examples, but the following examples are merely illustrative to aid in understanding the present invention, and the content of the present invention is not limited to the following examples.

[0064] [Example]

[0065] Example 1: Preparation of Surface-Modified MXene

[0066] (1) Preparation of reduced Ti3C2(rTi3C2)

[0067] Ti3C2 was prepared by etching Ti3AlC2 using an HF etching solution. Ti3AlC2MAX powder (1 g) was placed in an aqueous HF solution (10 mL) and stirred at 33°C for 3 days. After the reaction was completed, the resulting material was collected, washed several times with deionized water, and centrifuged at 5000 rpm until the pH of the supernatant approached 7. Subsequently, the Ti3C2Mxene powder was collected and dried overnight in a 60°C oven.

[0068] Subsequently, a hydrothermal process was performed to exfoliate Ti3C2, and reduced Ti3C2 (rTi3C2) was prepared. The etched Ti3C2 MXene powder was etched in an ascorbic acid buffer solution (50 mL, mg mL). -1 They were dispersed in ) and subjected to sonication for approximately 30 minutes, after which hydrothermal reactions were carried out at 180°C for 3 and 6 hours, respectively. These were named reduced Ti3C2 (rTi3C2) and excess reduced Ti3C2 (Ex-rTi3C2) MXenes, respectively. The suspension produced after the reaction was washed with acetone, and the powder was collected by repeating centrifugation at 10,000 rpm for 20 minutes three times, followed by drying overnight. Hydrothermal exfoliation and oxygen vacancies are formed simultaneously, and Ti3C2 By further isolating MXene nanosheets, a thinner structure and increased surface area were secured, while oxygen vacancies were introduced to improve electronic conductivity and intermediate adsorption capacity.

[0069] Fig. 1a is rTi3C2 This is a schematic diagram illustrating the synthesis process of an electrocatalyst, b shows the X-ray diffraction (XRD) patterns and magnified XRD patterns of Ti3Al2C2, Ti3C2, rTi3C2, and Ex-rTi3C2 (excess reduced Ti3C2) catalysts, and c and d are Raman spectra, where c is the low wavenumber region (200 cm⁻¹) of Ti3C2, rTi3C2, and Ex-rTi3C2. -1 to 8800 cm -1 ),d is the high wavenumber region (1,000 cm -1 to 1,800 cm -1This shows the Raman spectrum of ). XRD analysis confirmed that the Al layer was successfully removed, and it was observed that the (104) peak near 39° of Ti3AlC2 had almost disappeared (Fig. 1b). In addition, the phenomenon of the (002) reflection plane near 9.8° becoming distinctly wider and shifting to a lower angle indicates an increase in the interlayer spacing, which is interpreted as promoting electrolyte penetration and ion insertion during the redox process. During the etching process, hydrogen bonds and van der Waals forces were destroyed, causing the interlayer spacing to expand, which can also be confirmed in the X-ray diffraction (XRD) pattern. In Raman spectroscopy (Fig. 1c), at 200 cm⁻¹ -1 up to 800 cm -1 Characteristic vibration modes appeared in the range of approximately 205 cm -1 The peak observed at corresponds to the Ti-C vibration, and at 230 cm⁻¹ -1 to 470 cm -1 The area around 550 cm represents the in-plane (Eg) vibration of the surface group bonded to the Ti atom. -1 to 730 cm -1 The range is primarily attributed to carbon vibrations (Eg and A1g modes) and is utilized as a fingerprint area to identify surface groups. Additionally, approximately 1350 cm -1 (D band) and 1580 cm -1 The peak observed in the (G band) indicates a graphene-based carbon structure (Fig. 1d), showing that some graphene domains are retained along with structural disorder, contributing to improved electrical conductivity.

[0070] (2) Preparation of surface-treated rTi3C2 (rTi3C2-T)

[0071] rTi3C2 A cathode was prepared using an electrocatalyst, and surface-treated rTi3C2 (rTi3C2-T) was prepared by electroactivating it in an alkaline medium (0.1 M KOH) (Fig. 2). Specifically, to induce surface changes in rTi3C2, -0.1 V in a 0.1 M KOH solution RHE up to -0.4 V RHE The potential was applied for 1 to 40 cycles. As a result, as shown in Fig. 2, -O, -OH (hydroxide), and -OOH ((oxy)hydroxide groups) were introduced on the surface due to the bonding of H atoms and O atoms. These surface species can optimize charge transfer and stabilize key intermediates, thereby regulating the oxygen evolution reaction (OER) pathway and promoting a transition to an Oxide Pathway Mechanism (OPM) that is more efficient than the adsorbate evolution mechanism (AEM) / lattice oxygen mechanism (LOM).

[0072] Example 2: Oxygen evolution reaction (OER)

[0073] An oxygen evolution reaction system was constructed and evaluated using the rTi3C2-T catalyst prepared in Example 1. To evaluate electrochemical performance, an electrochemical cell of a three-electrode system was constructed using a potentiostat (Autolab Instrument). The system consisted of a working electrode, a platinum (Pt) counter electrode, and an Ag / AgCl reference electrode. A 0.5 M H2SO4 solution was used as the electrolyte. All potentials were converted to the reversible hydrogen electrode (RHE) reference according to the Nernst equation (ERHE = E°SCE + 0.0591 × pH + 0.197 V, at 25°C). The linear sweep current-voltage (LSV) was 1.1 V RHE to 2.2 V RHE 10 mV s in the interval -1 It was performed at the scan speed of .

[0074] Figures 3a to 3c show the electrocatalytic OER performance of Ti3C2, Ti3C2-T, rTi3C2, Ti3C2-T, Ex-rTi3C2, and Ex-rTi3C2-T catalysts evaluated in a 0.5 M H2SO4 electrolyte under acidic conditions, (a) LSV curve, (b) 10 mA cm⁻¹ -2 This shows the corresponding overpotential at, and the Tafel curve derived from the LSV curve of (a). The OER activity of all MXene-based electrode catalysts was determined by linear sweep ampolometric method (LSV, 10 mV s⁻¹) in a three-electrode cell in 0.5 M H₂SO₄ solution. -1 It was evaluated without iR correction as (Fig. 3a). The LSV curves showed enhanced catalytic activity in all treated MXene samples, among which rTi3C2-T showed 10 mA cm⁻¹. -2The lowest OER overvoltage was recorded at approximately 0.65 V. This represents a decrease of about 11% compared to untreated rTi3C2 (0.73 V) and about 27% compared to pristine Ti3C2. Additionally, rTi3C2-T compared to untreated rTi3C2 (296 mV dec -1 High Tafel slope compared to ) (355 mV dec -1 It shows ), suggesting a change in the reaction mechanism after cathodic treatment (Fig. 3b and c).

[0075] Figures 4a to 4c show the modified MXene observed during the OER activation process, where a is the result of normalizing the intensity peaks of Ti3C2O(OH) and Ti3C2(OH)2 with respect to the intensity peak of Ti3C2O2, and b is SO4 in the Raman spectrum. 2- band (960 cm) -2 ) and HSO4 - band (1040 cm) -1 Figure 4a shows the observation results, and c confirms the stability of the modified MXene during OER measurement through the analysis of the corresponding intensity peaks. Figure 4a summarizes the major Raman peaks observed during the reaction process. After 10 minutes from the start of the reaction, Ti3C2O(OH) and Ti3C2(OH)2 types increased significantly, which was confirmed by an increase in the -O(OH) / =O ratio and -(OH) / =O ratio, respectively. These results suggest that initial oxidation occurred on the surface of the rTi3C2-T MXene catalyst. Figures 4b and c show sulfate ions (SO4) over time at the rTi3C2-T electrode. -2 This is the result of confirming the change in ). SO4 in the Raman spectrum -2 960 cm -1 Peak and HSO4 - 1040 cm -1 The peak initially showed increasing intensity, followed by a gradual stabilization as OER progressed. This indicates an increase in sulfate ion concentration and HSO4 due to localized proton accumulation during the water oxidation process.- It originates from the dissociation of. As a result, SO4 -2 It is possible that strong hydrogen bonds were formed between the sulfate and water molecules. Sulfate ions can enhance OER activity by accelerating the reorganization of metal-(oxy)hydroxide catalysts and stabilizing reaction intermediates.

[0076] Figures 5a and 5b show the results of OER intermediate analysis of rTi3C2 and rTi3C2-T electrocatalysts in electrolytes containing (a) 0.5 M TMAOH and (b) 0.5 M MeOH, respectively. The figure is at 1.2 V RHE at 2.2 V RHE This compares the percentage change in current density before and after the addition of TMAOH and MeOH within the potential range up to . In the TMAOH experiment (Fig. 5a), rTi3C2-T showed relatively less current suppression due to TMAOH even at high voltages (>1.8 VRHE), suggesting that the LOM pathway was suppressed and the AEM or OPM pathways were dominant. On the other hand, rTi3C2 exhibited greater current suppression at high voltages due to partial involvement of the LOM pathway. In the MeOH experiment (Fig. 5b), the switching of mechanisms was clearly distinguishable depending on the voltage range. 1.4 V RHE to 1.6 V RHE In this range, the current increased upon MeOH addition, indicating that the AEM pathway operated predominantly, and it is possible that the MeOH oxidation (MOR) effect also played a partial role. In the 1.6 VRHE to 2.0 VRHE range, the addition of MeOH reduced the current, indicating that the OPM pathway operated predominantly. At the high voltage of 2.0 V RHE to 2.2 V RHEIn this region, the current increases again, which is interpreted as a mixed mechanism involving the combined influence of OPM and MOR or the parallel involvement of LOM. Through this, it was confirmed that the OER activity of rTi3C2 was significantly enhanced via precisely controlled cathodic treatment (rTi3C2-T), and that the OER mechanism shifts to OPM in the initial AEM-dominated region, expanding into a mixed pathway of OPM and LOM at high voltages.

[0077] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0078] The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included within the scope of the present invention.

Claims

1. A MXene electrochemical catalyst comprising a MXene represented by the following chemical formula 1: [Chemical Formula 1] M n+1 X n T x , In the above chemical formula 1, M is a transition metal selected from elements belonging to groups 3 through 6 of the periodic table, and X is C, N, or a combination thereof, and T x is one that contains a (oxy)hydroxide group (-OOH), and n is 1, 2, or 3.

2. In Paragraph 1, A MXene electrochemical catalyst in which M is a transition metal selected from Sc, Y, Lu, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W.

3. In Paragraph 1, The above MXene is a MXene electrochemical catalyst comprising Ti2C, Ti3C2, Ti4N3, V4C3, Nb4C3, Ta4C3, Ti3N2, Zr3C2, Ti3(CN), V2C, Zr2C, Cr2C, Hf2N, Hf2C, Zr2N, V2N, Nb2C, Ta2C, W2C, Cr2N, or Mo2C.

4. In Paragraph 1, The above T x A MXene electrochemical catalyst comprising one or more additionally selected from an oxo group (=O) and a hydroxide group (-OH).

5. In Paragraph 1, The above MXene electrochemical catalyst is a MXene electrochemical catalyst having an exfoliated layered structure.

6. In Paragraph 5, A MXene electrochemical catalyst having a single layer thickness of 1 nm to 100 nm.

7. In Paragraph 1, The above MXene electrochemical catalyst is a MXene electrochemical catalyst used in an oxygen evolution reaction.

8. Hydrothermally treating pristine MXene to obtain reduced MXene; and Electroactivating the above reduced MXene using an alkaline solution to obtain MXene represented by the following chemical formula 1. Method for preparing a MXene electrochemical catalyst comprising: [Chemical Formula 1] M n+1 X n T x , In the above chemical formula 1, M is a transition metal selected from elements belonging to groups 3 through 6 of the periodic table, and X is C, N, or a combination thereof, and T x is one that contains a (oxy)hydroxide group (-OOH), and n is 1, 2, or 3.

9. In Paragraph 8, A method for manufacturing a MXene electrochemical catalyst, wherein the above hydrothermal treatment is performed for 2 to 5 hours.

10. In Paragraph 8, A method for preparing a MXene electrochemical catalyst, wherein the alkaline solution comprises one or more selected from KOH solution, NaOH solution, LiOH solution, and CsOH solution.

11. In Paragraph 8, The above electroactivation is -0.1 V RHE up to -0.4 V RHE A method for manufacturing a MXene electrochemical catalyst, which is performed by applying a potential of a range.

12. An oxygen evolution reaction system comprising a MXene electrochemical catalyst according to claim 1.

13. In Paragraph 12, The above oxygen generation reaction system is an oxygen generation reaction system that is a water electrolysis system, a metal-air battery system, or a carbon dioxide electrolysis (oxidation) system.

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