KR20220066717A - Composite for hydrogen-generating catalyst having metal-organic framework and method of preparing the same - Google Patents

Abstract

The present invention relates to a composite for a hydrogen generation catalyst which comprises: a body unit in which a first transition metal includes a metal-organic framework (MOF); and a plurality of primary particles provided on an outer surface of the body unit and including a second transition metal.

Description

Composite for hydrogen-generating catalyst having metal-organic framework and method of preparing the same

The present invention relates to a composite for a hydrogen production catalyst including a metal organic framework and a method for preparing the same, and more particularly, to a hydrogen production catalyst including a metal organic framework capable of replacing a platinum catalyst with high efficiency at low cost It relates to a composite for use and a method for manufacturing the same.

The use of fossil fuels is a cause of climate change, and various studies are conducted to provide alternative energy sources. Among these alternative energy, energy using hydrogen is applied in various countries around the world due to characteristics such as high energy efficiency and low emission and regeneration of side reaction materials.

As a method for producing hydrogen, various methods such as water decomposition, gasification using biomass, cryogenic distillation, and reforming of fossil fuels have been studied. Among them, water electrolysis is one of the easiest methods to generate almost pure hydrogen, but a catalyst is required to increase the current density and reaction rate in electrolysis.

Platinum is the best material for electrode manufacturing in hydrogen evolution reaction (HER), but its high cost limits its industrial application. Therefore, various studies have been conducted to cope with Pt catalysts in HER with low-cost catalysts including transition metal dichalcogenide (TMD), non-noble metal, metal organic framework (MOF) and MXene.

(Prior Patent)

Japanese Patent Application Laid-Open No. 2018-531780 (2018.11.01)

It is an object of the present invention to provide a complex for a hydrogen production catalyst including a metal organic framework capable of replacing a platinum catalyst and capable of producing high-efficiency hydrogen at low cost in the process of producing hydrogen using water decomposition, and a method for preparing the same it is for

In addition, another object of the present invention is to provide a composite for a hydrogen production catalyst including a metal-organic framework prepared in a novel manner, and a method for preparing the same.

According to one aspect of the present invention, embodiments of the present invention include a complex for a hydrogen production catalyst and a method for preparing a complex for a hydrogen production catalyst.

In an embodiment, the first transition metal includes a body portion including a metal-organic framework (MOF); And it is provided on the outer surface of the body portion, a plurality of primary particles comprising a second transition metal; includes a hydrogen-generating catalyst composite comprising a.

In an embodiment, the metal organic framework may include MOF-74 based, and the first transition metal may include nickel (Ni) or cobalt (Co).

In an embodiment, the second transition metal may be formed of a metal different from the first transition metal.

In an embodiment, the first transition metal may include nickel (Ni) or cobalt (Co), and the second transition metal may include molybdenum (Mo) or tungsten (W).

In one embodiment, the primary particles include MoS _x , the primary particles are provided to cover the outer surface of the body portion, at least a portion of the body portion may be provided to be exposed to the outside.

In one embodiment, based on 100 parts by weight of the body part, the primary particle may be provided in an amount of 20 parts by weight to 60 parts by weight.

In an embodiment, the body portion may have crystal planes (2 −1 0) and (3 0 0) measured by an XRD spectrum, and the primary particle may have an amorphous structure.

In one embodiment, when the first transition metal is cobalt (Co), the shape of the body portion is provided with a rod shape, and when the first transition metal is nickel (Ni), the shape of the body portion is A plurality of rod-shaped primary particles are provided as secondary particles formed by agglomeration, and the primary particles are vertically anchored from the outer surface of the body part as nanoparticles.

In one embodiment, the starting potential by linear sweep voltammetry (LSV) is -280mV to -140mV when the first transition metal is Co, and 100mV to when the first transition metal is Ni 350mV may be included.

In an embodiment, the first transition metal is Co or Ni, the second transition metal is Mo, and the composite for the hydrogen generation catalyst may include 5 wt% to 40 wt% of a CoMoS phase or a NiMoS phase.

In one embodiment, the body portion may have a specific surface area of 300 m 2 /g to 500 m 2 /g.

In one embodiment, using a first solution containing a first transition metal to react for a first temperature and a first time to prepare a body portion; The body part is mixed with a second solution containing a second transition metal, and a third solution is added to react for a second temperature and a second time to form a plurality of primary particles containing a second transition metal on the outer surface of the body part. It includes; a method for producing a composite for a hydrogen generation catalyst comprising: the metal-organic framework is MOF-74-based, and the first transition metal is nickel (Ni) or cobalt (Co). .

In one embodiment, the first solution is Co(NO ₃ ) ₂ .6H ₂ O or Ni(NO ₃ ) ₂ .6H ₂ O, the first temperature is 80 ℃ to 120 ℃, the first time is 20 hours to 30 hours, the second solution is (NH ₄ ) ₂ MoS ₄ , the third solution is hydrazine hydrate, the second temperature is 200° C. to 300° C., and the second time is 8 hours. to 15 hours.

According to the present invention as described above, it is possible to provide a composite for a hydrogen production catalyst including a metal-organic framework capable of coping with expensive platinum used in water decomposition, and a method for producing the same.

In addition, according to the present invention, it is possible to provide a composite for a hydrogen production catalyst including a metal-organic framework having a high yield at a low cost and a method for preparing the same.

1A and 1B are diagrams schematically showing the shape of a composite for a hydrogen production catalyst according to an embodiment of the present invention.
1c is a view schematically showing how hydrogen is generated by the complex for a hydrogen production catalyst of the present invention.
Figure 2a is a diagram schematically showing a method of manufacturing a MoS _x /Co-MOF-74 composite.
Figure 2b is a view schematically showing a method of manufacturing the MoS _x /Ni-MOF-74 composite.
Figure 3a is a powder XRD spectrum of 40% MoS _x /Co-MOF-74.
3b is an FT-IR spectrum of Co-MOF-74.
Figure 3c is a graph showing the nitrogen adsorption and desorption of Co-MOF-74 and 40% MoS _x /Co-MOF-74.
4 shows (a) Co-MOF-74, (b) 20% MoS _x /Co-MOF-74, (c) 40% MoS _x /Co-MOF-74, (d) 60% MoS _x /Co- SEM images of MOF-74, (e) 80% MoS _x /Co-MOF-74, and (f) MoS _x .
5 is a TEM image of (a) and (d) Co-MOF-74, (b) and (e) MoS _x , (c) and (f) 40% MoS _x /Co-MOF-74, respectively.
6 is an XPS spectrum of Co-MOF-74 and 40% MoS _x /Co-MOF-74, (a) is Co 2 p, (b) is Mo 3 d and S 2 s, (c) is S 2 p is shown, respectively.
7 is (a) polarization curve, (b) Tafel slope, (c) EIS Nyquist plot of Co-MOF-74 and 20-100% MoS _x /Co-MOF-74 , (d) C _d and 40% MoS _x /Co-MOF-74 (e) A cycle test after 1000 cycles, (f) A graph showing a chronoamperometric curve at a fixed potential of 0.197 V.
Figure 8a is a powder XRD spectrum of 40% MoS _x /Ni-MOF-74.
8B is an FT-IR spectrum of Ni-MOF-74.
8c is a graph showing nitrogen adsorption and desorption of Ni-MOF-74 and 40% MoS _x /Ni-MOF-74.
9 shows (a) Ni-MOF-74, (b) 20% MoS _x /Ni-MOF-74, (c) 40% MoS _x /Ni-MOF-74, (d) 60% MoS _x /Ni- SEM images of MOF-74, (e) 80% MoS _x /Ni-MOF-74, and (f) MoS _x .
10 is a TEM image of (a) and (d) Ni-MOF-74, (b) and (e) MoS _x , (c) and (f) 40% MoS _x /Ni-MOF-74, respectively.
11 is an XPS spectrum of Ni-MOF-74 and 40% MoS _x /Ni-MOF-74, (a) is Ni 2 p, (b) is Mo 3 d and S 2 s, (c) is S 2 p is shown, respectively.
12 is (a) polarization curve, (b) Tafel slope, (c) EIS Nyquist plot of Ni-MOF-74 and 20-100% MoS _x /Ni-MOF-74 , (d) is a graph showing the cycle test after 2000 cycles of 40% MoS _x /Ni-MOF-74.

The details of other embodiments are included in the detailed description and drawings.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, and unless otherwise specified in the following description, the components, reaction conditions, and content of components are expressed in the present invention. It is to be understood that all numbers, values and/or expressions are modified in all instances by the term "about," as these numbers are inherently approximations reflecting the various uncertainties of measurement arising out of obtaining such values, among other things. . Also, when numerical ranges are disclosed in this description, such ranges are continuous and inclusive of all values from the minimum to the maximum inclusive of the range, unless otherwise indicated. Furthermore, when such ranges refer to integers, all integers inclusive from the minimum to the maximum inclusive are included, unless otherwise indicated.

Also, when a range is recited for a variable in the present invention, it will be understood that the variable includes all values within the recited range, including the recited endpoints of the range. For example, a range of “5 to 10” includes the values of 5, 6, 7, 8, 9, and 10, as well as any subranges such as 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc. It will be understood to include any value between integers that are appropriate for the scope of the recited range, such as 5.5, 6.5, 7.5, 5.5 to 8.5 and 6.5 to 9, and the like. For example, a range of “10% to 30%” includes values such as 10%, 11%, 12%, 13%, and all integers up to and including 30%, as well as 10% to 15%, 12% to 18%. It will be understood to include any subranges such as %, 20% to 30%, and the like, and also include any value between reasonable integers within the scope of the recited range, such as 10.5%, 15.5%, 25.5%, and the like.

1A and 1B are diagrams schematically showing the shape of a composite for a hydrogen production catalyst according to an embodiment of the present invention. 1c is a view schematically showing how hydrogen is generated by the complex for a hydrogen production catalyst of the present invention.

One embodiment of the present invention includes a body in which the first transition metal includes a metal-organic framework (MOF); And it is provided on the outer surface of the body portion, a plurality of primary particles comprising a second transition metal; includes a hydrogen-generating catalyst composite comprising a. The body portion may include a crystalline structure, and the primary particles may be amorphous nano-sized particles. In addition, the second transition metal may be formed of a metal different from the first transition metal.

The metal organic framework may be MOF-74 based, and the first transition metal may include nickel (Ni) or cobalt (Co). Specifically, the first transition metal may include nickel (Ni) or cobalt (Co), and the second transition metal may include molybdenum (Mo) or tungsten (W). In this case, the second transition metal is MoS _x or It may be provided in the form of a sulfur compound of WS _x .

The primary particles may include MoS _x , and the primary particles may be provided to cover the outer surface of the body portion, and at least a portion of the body portion may be exposed to the outside.

G_H)의 계산은 수소생성에서 베어(bare) MoS₂보다는 Co-도핑 MoS₂ 및 Fe-도핑 MoS₂이 더 우수하다. 또한, Co, Ni, Fe 이온이 MoS₃ 필름 성장을 촉진시켜, 표면적을 증가시키고 이에 의하여 수소생성 성능을 향상시킬 수 있다. TiO₂ 나노튜브 어레이에 전착된 MoS_xCo_y는 Mo-S-Co 결합을 형성하여 활성중심(불포화 Mo 및 S 자리)의 형성을 향상시키고, HER에서 MoS_x에서 전기촉매 활성을 향성시킨다. 이는 CoMoS 상이 형성되어, MoS₂의 S-에지에서의 R_ct 및

G_H가 감소되었기 때문으로, HER 수율의 향상은 구조 내에서 Co-S-W 상이 형성된 M 도핑 WS_x (M = Co, Ni)에서도 유사하게 발생한다.In general, crystalline molybdenum disulfide (c-MoS ₂ ) is used as an electrocatalyst and a photocatalyst in a hydrogen evolution reaction (HER). In addition, excellent performance is also exhibited in the catalytic electrocatalyst HER containing MoS ₂ as a carrier. For example, MoS ₂ electrodeposited on polypyrrole is used as a cathode for hydrogen production, and it shows a low Tafel slope of 29 mV decade ^-1 , which shows similar performance to the used Pt catalyst. In the case of hydrodesulfurization and oxygen evolution reaction (OER), doping of transition metals (eg, Co, Ni, Cu and Fe) was performed on transition metal dichalcogenide (TMD). , Co-SW, Co-S-Mo, and Ni-SW, such as by forming a bimetal active center through a sulfur bond, the chemical structure and shape have been modified. Doping of Co ions into the MoS ₂ lattice reduces R _ct , and promotes the formation of more active sites to improve water separation performance. Hydrogen absorption free energy of M-doped MoS ₂ (M = Co, Ni, Fe, Cu) in HER (

Calculation of G _H ) is better for Co-doped MoS ₂ and Fe-doped MoS ₂ than for bare MoS ₂ in hydrogen production. In addition, Co, Ni, Fe ions promote the growth of the MoS ₃ film, thereby increasing the surface area and thereby improving the hydrogen production performance. MoS _x Co _y electrodeposited on the TiO ₂ nanotube array improves the formation of active centers (unsaturated Mo and S sites) by forming Mo-S-Co bonds, and enhances the electrocatalytic activity in MoS _x in HER. This is due to the formation of a CoMoS phase, which at the S-edge of MoS ₂ R _ct and

Because G _H was decreased, The improvement of HER yield similarly occurred in M-doped WS _x (M = Co, Ni) where Co-SW phase was formed in the structure.

Metal-organic frameworks (MOFs) are a class of porous material products, composed of organic linkers such as metal clusters/ions, and are a new member of the family. They consist of metal clusters/ions and organic linkers and are referred to as secondary building units (SBUs). The structure of the MOF can be modified because the chemical composition can be adjusted, and the choice of SBU depends on the specific application. MOFs are used in a wide range of applications, such as gas absorption, catalysis, sensors, and drug delivery. Since MOF has a high surface area and high porosity, it is widely applied in catalysts.

On the other hand, these MoS ₂ and MOF alone has a problem in that the performance is lower than that of commercially available Pt in a reaction for generating hydrogen using water decomposition.

In an embodiment of the present invention, MoS ₂ and By using MOF but modifying them, MoS ₂ and It is possible to provide a composite for a hydrogen production catalyst that has better performance than MOF and can replace commercially available Pt.

Specifically, the MOF is transformed into a first transition metal to prepare a body part, and then by providing a sulfur compound containing a second transition metal of a controlled size and shape on the outer surface of the body part including the first transition metal, It is possible to further improve the yield of hydrogen production in the composite for a hydrogen production catalyst.

The first transition metal may be cobalt or nickel, and the second transition metal may include a different transition metal from the second transition metal. More specifically, the second transition metal may be molybdenum. In addition, the MOF may include a MOF-74 series.

When the first transition metal is cobalt (Co), the body portion has a rod shape. When the first transition metal is nickel (Ni), the body portion has a plurality of rod shapes. shape) may be provided as secondary particles formed by agglomeration of primary particles of the shape. In addition, the primary particles may be provided by being vertically anchored from the outer surface of the body part as nanoparticles.

Based on 100 parts by weight of the body part, the primary particles may be provided in 20 parts by weight to 60 parts by weight, and when the primary particles are less than 20 parts by weight, a phase by Mo-S-Co or Mo-S-Ni bonding is not formed. Therefore, the catalytic activity is reduced, and when it exceeds 60 parts by weight, the primary particles cover the body as a whole, and the water decomposition yield may be reduced.

Specifically, the first transition metal may be Co or Ni, the second transition metal may be Mo, and the composite for the hydrogen generation catalyst may include 5 wt% to 40 wt% of a CoMoS phase or a NiMoS phase. In the composite for the hydrogen generation catalyst, if the content of the CoMoS phase or the NiMoS phase is less than 5 wt%, the catalytic activity is low, and if it exceeds 40 wt%, the durability may be relatively reduced.

In addition, the body portion may have a specific surface area of 300 m / g to 500 m / g, and if it is less than 300 m / g, the adhesion amount of the primary particles is low, and if it exceeds 500 m / g, the primary particles are uniformly attached. difficult and problematic

An onset potential by a linear sweep voltammetry (LSV) may be -280mV to -140mV when the first transition metal is Co, and 100mV to 350mV when the first transition metal is Ni. Since the initiation potential for the linear sweep voltammetry can be controlled according to the type of the first transition metal, the use of the hydrogen-generating catalyst composite according to the present embodiment can be more diversely applied.

According to another aspect of the present invention, the present invention comprises the steps of using a first solution containing a first transition metal to react for a first temperature and a first time to prepare a body portion; and a plurality of primary particles containing a second transition metal on the outer surface of the body by mixing the body with a second solution containing a second transition metal, adding a third solution, and reacting at a second temperature and for a second time Including; and, the metal organic framework is MOF-74-based, and the first transition metal is nickel (Ni) or cobalt (Co). do.

내지 120

이고, 상기 제1 시간은 20시간 내지 30시간이고, 상기 제2 용액은 (NH₄)₂MoS₄이고, 상기 제3 용액은 히드라진 하이드레이트이고, 상기 제2 온도는 200

내지 300

이고, 상기 제2 시간은 8시간 내지 15시간일 수 있다.The method for preparing the composite for the hydrogen generation catalyst may use a solvothermal synthesis method, and the first solution is Co(NO ₃ ) ₂ .6H ₂ O or Ni(NO ₃ ) ₂ .6H ₂ O, and the first temperature is 80

to 120

and the first time is 20 to 30 hours, the second solution is (NH ₄ ) ₂ MoS ₄ , the third solution is hydrazine hydrate, and the second temperature is 200

to 300

and the second time period may be 8 hours to 15 hours.

When the first temperature and the first time period, and the second temperature and the second time period are performed within the above-described ranges, the reaction is completed and a complex for a hydrogen generating catalyst having a desired crystallinity can be prepared.

Hereinafter, Examples and Comparative Examples of the present invention will be described. However, the following examples are only preferred examples of the present invention, and the scope of the present invention is not limited by the following examples.

1. Preparation of composite for hydrogen production catalyst

ingredient

In the following, the materials used in this experiment were purchased from the following companies.

Co(NO ₃ ) ₂ .6H ₂ O, H ₄ DHBDC, 5% Nafion solution, hydrazine hydrate, and (NH ₄ ) ₂ MoS ₄ were purchased from Sigma Aldrich, DMF was It was purchased from Daihan Chemical Co. Ltd. and used. Ethanol and methanol were purchased from Daejung Co. Ltd., and deionized water was prepared using a Millipore Mili-Q machine.

Preparation Example 1 (Preparation of Co-MOF-74)

0.1 mmol Co(NO ₃ ) 2.6H ₂ O(Cobalt nitrate hexahydrate) in _a mixed solvent of 3 mL N,N-dimethylformamide, 3 mL ethanol and 3 mL DI water , 0.05 mmol H ₄ DHBDC acid (2,5-dihydroxybenzenedicarboxylic acid) was added to prepare a reaction mixture. The prepared reaction mixture was stirred for 30 minutes, transferred to a glass vial (10 mL), and reacted in an oven at 100° C. for 24 hours. After the reaction was completed, the glass vial was cooled to room temperature and centrifuged to obtain dark purple crystals. The obtained crystals were washed several times with methanol and then vacuum dried at 250° C. to prepare Co-MOF-74, and then stored in a glass vial.

Preparation Examples 2 to 5 (Preparation of MoS _x /Co-MOF-74 composite)

100 mg Co-MOF-74 prepared in Preparation Example 1 was mixed with (NH ₄ ) ₂ MoS ₄ (Ammonium tetrathiomolybdate) with different content ranges as shown in Table 1 below, and then DMF (100 mL) was added to the mixture was prepared. While the prepared mixture was magnetically stirred, 1 mL of hydrazine hydrate was added dropwise from the top for 1 hour to prepare a compound. Then, the prepared compound was placed in a stainless steel autoclave treated with Teflon and maintained at 200° C. for 10 hours. Finally, the product was isolated, washed with deionized water, and dried in a vacuum oven at 60 °C. Figure 2a is a diagram schematically showing a method of manufacturing a MoS _x /Co-MOF-74 composite.

division Preparation 2 Preparation 3 Preparation 4 Preparation 5 20% MoS _x /Co-MOF-74 40% MoS _x /Co-MOF-74 60% MoS _x /Co-MOF-74 80% MoS _x /Co-MOF-74 MoS _x content 20 wt% 40wt% 60wt% 80 wt%

Production Example 6 (Preparation of Ni-MOF-74)

For Ni-MOF-74, a solvothermal synthesis method was used. 1 g Ni(NO ₃ ) ₂ .6H ₂ O and 0.2 g H ₄ DHBDC acid were added to 100 mL of a solvent mixed with DMF, deionized water and C ₂ H ₅ OH (vol%, 1:1:1) and stirred to obtain a reaction mixture was prepared with The prepared reaction mixture was stirred for 1 hour and placed in a reactor composed of a stainless steel autoclave treated with Teflon. The reactor was transferred to an oven and maintained at 100° C. for 24 hours. Then, after cooling to 25 ℃, a product containing yellowish-brown powder was separated using a centrifuge. The separated product was rinsed 4 times with methanol to remove residue, and dried in a vacuum oven at 170° C. for 5 hours to prepare Ni-MOF-74, which was stored in a glass vial.

Preparation Examples 7 to 10 (Preparation of MoS _x /Ni-MOF-74 composite)

100 mg Ni-MOF-74 prepared in Preparation Example 6 was mixed with (NH ₄ ) ₂ MoS ₄ having different content ranges as shown in Table 2 below, and then DMF (100 mL) was added to prepare a mixture. While the prepared mixture was magnetically stirred, 1 mL of hydrazine hydrate was added dropwise from the top for 1 hour to prepare a compound. Then, the prepared compound was placed in a stainless steel autoclave treated with Teflon and maintained at 200° C. for 10 hours. Finally, the product was isolated, washed with deionized water, and dried in a vacuum oven at 60 °C. Figure 2b is a diagram schematically showing a method of manufacturing a MoS _x /Co-MOF-74 composite.

division Preparation 7 Preparation 8 Preparation 9 Preparation 10 20% MoS _x /Ni-MOF-74 40% MoS _x /Ni-MOF-74 60% MoS _x /Ni-MOF-74 80% MoS _x /Ni-MOF-74 MoS _x content 20 wt% 40wt% 60wt% 80 wt%

2. Evaluation of composites for hydrogen production catalysts

Electrochemical performance evaluation

The HER electrocatalytic activity of the prepared hydrogen-generating catalyst complex was evaluated at room temperature using a three-electrode system and an electrochemical analyzer (Ivium potentiostat V55630). Here, the sample is coated on a working electrode, a glassy carbon electrode (GCE) (0.2 mg cm ^-2 ), a graphite rod as a counter electrode, and Hg/Hg ₂ Cl ₂ (saturated KCl) or RHE (reversible hydrogen) as a reference electrode. electrode), and 0.5 MH ₂ SO ₄ was used as the electrolyte.

As the working electrode related to Preparation 1 to 5 in preparation, in order to prevent the catalyst from adhering to the electrode, 1 mg catalyst, 1 μL DMF, and 80 μL Nafion (Nafion, 5%) were used to prepare a mixture using was used. 0.5 μL of the mixture was sonicated for 1 hour, and then coated with 3 mm diameter GCE.

The obtained potential (vs. Hg/Hg ₂ Cl ₂ ) was converted to a Real Hydrogen Electrode (RHE) using Equation 1 below.

(Equation 1) E(RHE) = E(Hg/Hg ₂ Cl ₂ ) + 0.059 pH + E ⁰ (Hg/Hg ₂ Cl ₂ )

As a working electrode related to Preparation Examples 6 to 10, a mixture was prepared using 4 mg catalyst, 1 μL DMF, and 80 μL Nafion (Nafion, 5%).

The obtained potential (vs. RHE) was converted to RHE (Real Hydrogen Electrode) using Equation 2 below.

(Equation 2) E (RHE) = E ⁰ (SCE) + E (SCE) + 0.059 pH

LSV (linear sweep voltammetry) method was performed at a scan rate of 10 mV/s, EIS (electrochemical impedance spectroscopy) was 0.2 V (vs. RHE), and the frequency range was 100000 Hz to 0.1 Hz. Catalyst stability was confirmed by cyclic voltammetry at a scan rate of 50 mV/s and chronoamperometry at -0.197 V.

Material characterization

The phase of each material was measured by XRD (D8-Advance/Bruker-AXS, Cu Ka radiation). The surface area of the material was confirmed by BET (Brunauer-Emmett-Teller) method, and an FT-IR spectrum was obtained using a Perkin Elmer Spectrum GX1 spectrometer. SEM images were acquired with SIGMA/Carl Zeiss, HR-TEM images were acquired with JEOL-2100F (Japan), and XPS was confirmed under high vacuum using a Mg Kα source and pass energy of 40 eV or 50 eV.

3. Evaluation result

(1) Evaluation of Preparation Examples 1 to 5

Figure 3a is the powder XRD spectrum of 40% MoS _x /Co-MOF-74, Figure 3b is the FT-IR spectrum of Co-MOF-74, Figure 3c is Co-MOF-74 and 40% MoS _x /Co- It is a graph showing the nitrogen adsorption and desorption of MOF-74.

Figure 3a shows the crystallinity of 40% MoS _x /Co-MOF-74 confirmed by XRD. Two types of peaks of Co-MOF-74 were measured at 2θ = 6.8 ^o and 2θ = 11.7 ^o , and were identified as (2 -1 0) plane and (3 0 0) plane, respectively. This means that Co-MOF-74 was successfully synthesized. Figure 3b is a result of confirming the formation of the active Co-MOF-74 according to Preparation Example 1 by FT-IR spectrum. The very low vibration signal intensity at 1662 cm ^-1 is considered to be due to the DMF solvent. A number of guest molecules were removed from the Co open site by thermal activity. In addition, the bands at 1554 cm ^-1 and 1409 cm ^-1 are, respectively, of the organic linker. It is judged as stretching vibrations of C=O (-COOH) and C=C (aromatic ring) bonds. 3c is a pore characteristic evaluated by a nitrogen adsorption isotherm (N ₂ sorption isotherm) according to Preparation Example 1 (Co-MOF-74). Specifically, Co-MOF-74 had a specific surface area of 335.4 m ² /g, a pore volume of 0.021 cm ³ /g, and an average pore size of 3.06 nm. After mixing Co-MOF-74 and 40wt% MoS _x , the surface area of 40% MoS _x /Co-MOF-74 was reduced to 126.6 m ² /g. The pore volume remained unchanged (0.022 cm ³ /g), and the average pore size increased to 7.39 nm.

4 shows (a) Co-MOF-74, (b) 20% MoS _x /Co-MOF-74, (c) 40% MoS _x /Co-MOF-74, (d) 60% MoS _x /Co- SEM images of MOF-74, (e) 80% MoS _x /Co-MOF-74, and (f) MoS _x .

4 (a) to (f) is a morphology of MoS _x /Co-MOF-74 prepared using Co-MOF-74 and (NH ₄ ) ₂ MoS ₄ of different contents of 0 to 100 wt%. SEM image shown. Referring to FIG. 4 , it was observed that MoS _x on the outer surface of Co-MOF-74 gradually increased from (a) to (e). On the other hand, when a low content of 20% (NH ₄ ) ₂ MoS ₄ was used, it was confirmed that a small portion of the Co-MOF-74 crystal was not coated. At a high content, the outer surface of Co-MOF-74 was covered, thereby confirming that the MoS _x /Co-MOF-74 complex was successfully synthesized. Referring to FIG. 4(c), 40% MoS _{x is} sufficient to completely cover Co-MOF-74, but overloading MoSx (>40%) on the outer surface of Co-MOF-74 prevents the formation of the CoMoS phase, The complex may lead to a decrease in the activity of the catalyst.

5 is a TEM image of (a) and (d) Co-MOF-74, (b) and (e) MoS _x , (c) and (f) 40% MoS _x /Co-MOF-74, respectively. 5(a) and 4(b), Co-MOF-74 appeared in the form of a rod shape, and MoS _x was observed in the form of nanoparticles. In Fig. 5(c), a TEM image of 40% MoS _x /Co-MOF-74 showed that MoS _{x was} vertically fixed on the outer surface of Co-MOF-74.

6 is an XPS spectrum of Co-MOF-74 and 40% MoS _x /Co-MOF-74, (a) is Co 2 p, (b) is Mo 3 d and S 2 s, (c) is S 2 p is shown, respectively.

Referring to FIG. 6(a), the two peaks corresponding to Co ²⁺ 2 p _1/2 and Co ²⁺ 2 p _3/2 in the XPS spectrum of Co 2 p have binding energies of 797.6 eV and 781.8 eV, respectively. appeared in the XPS spectrum of Co 2 p for the MoS _x /Co-MOF-74 complex. In addition, two new peaks at 779.2 eV and 793.9 eV for saturated Co indicate the presence of the CoMoS phase.

Co-MOF-74, which normally has an open metal site (OMS) (Co site), can easily interact with heteroatoms. Therefore, the Co site is predicted to interact with the S (or Mo) atom of MoSx to form the CoMoS phase. The content of the CoMoS phase in the 40% MoS _x /Co-MOF-74 composite was estimated to be 18.9%, which was shown in high-resolution Mo 3 d and S 2 s in FIG. 6(b). The two peaks at 228.8 eV and 231.9 eV are due to Mo ⁴⁺ , and the peaks at 235.8 eV and 232.7 eV are due to Mo ⁵⁺ . The S 2p peaks at 164.1 eV and 162.9 eV are due to disulfide S ₂ ^2- , and the divalent sulfide ion (S ^2- ) is due to peaks at 162.7 eV and 161.5 eV ( FIG. 6(c) ).

7 is (a) polarization curve, (b) Tafel slope, (c) EIS Nyquist plot of Co-MOF-74 and 20-100% MoS _x /Co-MOF-74 , (d) C _d and 40% MoS _x /Co-MOF-74 (e) A cycle test after 1000 cycles, (f) A graph showing a chronoamperometric curve at a fixed voltage of 0.197 V.

7 shows the electrocatalytic properties of HER (hydrogenation reaction) for Co-MOF-74, MoS _x /Co-MOF-74, and compatible Pt/C. Referring to FIG. 7( a ), in linear sweep voltammetry (LSV), the catalytic activity of Pt/C exhibited the best results at an onset potential of ~ 0mV. In addition, the onset potentials of MoS _x /Co-MOF-74 having 20, 40, 60, 80% (NH ₄ ) ₂ MoS ₄ were -287, -147, -188, and -189 mV, respectively, and Co- The onset potentials of MOF-74 and MoS _x are respectively -589 and -177 mV. Here, it was confirmed that 40%MoS _x /Co-MOF-74 exhibited the best value. The Tafel slope shown in Figure 7 (b) is a result obtained by Figure 7 (a).

As a catalyst, Co-MOF-74 showed a relatively high Tafel slope of 249.2 mV decade ^-1 in hydrogen production. In addition, in Co-MOF-74 modified by MoS _x , the Tafel slope showed a tendency to decrease as the content of MoS _x increased. 40%MoS _x /Co-MOF-74 showed the lowest Tafel slope at 68.3mV decade ^-1 , and 20%MoS _x /Co-MOF-74 showed the highest Tafel slope at 132.6mV decade ^-1 . In the Tafel slope, 60%MoS _x /Co-MOF-74, 80%MoS _x /Co-MOF-74 and MoS _x showed low values at 68.8, 70.5 and 70.2 mV decade ^-1 , respectively. That is, it is judged that 40%MoS _x /Co-MOF-74 is due to the formation of a CoMoS phase that reduces the hydrogen absorption free energy, indicating that it is an optimal content to improve the catalytic activity of Co-MOF-74. In addition, MoS _x plays an important function in HER performance. First, it acts as a co-catalyst in a complex having an unsaturated atmosphere, such as Mo ⁴⁺ and Mo ⁵⁺ , and S ₂ ^2- acts as the center of HER catalytic activity. Second, MoS _x can generate a CoMoS phase to improve the HER performance of the MoS _x /Co-MOF-74 composite. Tafel slope values are associated with HER mechanisms, including Volmer (120 mV decade ^-1 ), Heyrovsky (40 mV decade ^-1 ), and Tafel (30 mV decade ^-1 ). have. In general, there are two mechanisms by which water is separated from an acidic medium to generate hydrogen, which consists of a Volmer-Heyrovsky reaction and a Volmer-Tafel reaction, and is expressed by the following formulas (1) to (3).

Volmer reaction: H ₃ O ⁺ + e ^- → H* + H ₂ O (1)

Heyrovsky reaction: H ₃ O ⁺ + e ^- + H* → H ₂ + H ₂ O (2)

Tafel reaction: H* + H* → H ₂ (3)

The Co-MOF-74 complex modified by MoS _x exhibits a Tafel slope in the range of 68 to 133 mV decade ^-1 , and is a HER mechanism corresponding to the Volmer-Heyrovsky reaction, including the discharge process and electrochemical desorption.

Referring to FIG. 7(c), the HER yield was confirmed by measuring EIS at 0.2 V in an acidic solution (0.5 MH ₂ SO ₄ ). The equivalent circuit includes R _{s (} internal resistance), R _ct (charge-transfer resistance) and CPE (constant phase element) (internal view of FIG. 7(c)). R _ct of the specimen including the catalyst resistance of GCE (R ₁ ) and the catalyst resistance of the electrolyte is shown in Table 3 below.

Sample R _S (Ω) R ₁ (Ω) R ₂ (Ω) Co-MOF-74 21.7 11390 3375 20% MoS _x /Co-MOF-74 13.5 285.8 101.7 40% MoS _x /Co-MOF-74 12.08 44.8 9.75 60% MoS _x /Co-MOF-74 17.8 58.6 21.5 80% MoS _x /Co-MOF-74 11.9 73.1 28.1 MoS _x 21.4 34.1 15.6

As described above, Co-MOF-74 has a high Tafel slope and low electrocatalytic activity with a high R ₁ of 11390 Ω. As the ratio of MoS _x increased, it was confirmed that the Rct of the MoS _x /Co-MOF-74 composite was significantly reduced. Among them, it was confirmed that 40% MoS _x /Co-MOF-74 with R1 and R2 of 44.8 Ω and 9.75 Ω, respectively, was the best. In addition, in order to confirm the double-layer capacitance (C _dl ) related to the electrochemically active surface area, CV was measured at various scan rates in the potential range of 0.1 to 0.2V (vs. _RHE ). As a result, the C _dl value was It was confirmed that the increase and decrease in the complex. In particular, it was confirmed that 40% MoS _x /Co-MOF-74 showed the highest C _dl at 0.84 mF/cm 2 , and MoS _x had a low C _dl of 0.43 mF/cm 2 . That is, it was confirmed that MoS _x /Co-MOF-74 had excellent catalytic activity compared to other composites.

The durability of 40% MoS _x /Co-MOF-74 as a catalyst was confirmed by the current density-voltage method. Referring to FIG. 7(e), it was confirmed that there was almost no change in the polarization curve after 1000 cycles, and it could be confirmed that the current density also did not change even after 12 hours (FIG. 7(f)). That is, it means that 40% MoS _x /Co-MOF-74 shows high catalytic activity and stability, and shows excellent ability as a HER catalyst.

As described above, the catalytic activity consisting of Co-MOF-74 alone, and (NH ₄ ) ₂ MoS ₄ in Co-MOF-74 were modified using MoS 4 as a precursor. By confirming the catalytic activity of Co-MOF-74, the HER performance was confirmed. Co-MOF-74 in the form of a rod shape was prepared by a solvothermal method, and the surface area was 335.4 m ² /g. The catalyst of 40% MoS _x /Co-MOF-74 has a Tafel slope of 68 mV decade ^-1 and an onset potential At -147 mV, it was confirmed that it works most effectively in hydrogen generation. In addition, 40% MoS _x /Co-MOF-74 showed high durability even after 1000 cycles, which is thought to be because the CoMoS phase promotes the catalytically active center and reduces the electron transfer resistance of Co-MOF-74. .

(2) Evaluation of Preparation Examples 6 to 10

Figure 8a is a powder XRD spectrum of 40% MoS _x /Ni-MOF-74, Figure 8b is an FT-IR spectrum of Ni-MOF-74. 8c is a graph showing nitrogen adsorption and desorption of Ni-MOF-74 and 40% MoS _x /Ni-MOF-74.

= 6.8^o 및 11.7^o의 두개의 피크가 나타났고, 이는 Ni-MOF-74가 잘 합성되었음을 의미한다. 40% MoS_x/Ni-MOF-74는 MoS_x가 장착되어 결정도가 상대적으로 감소하였으나, 전체적으로 Ni-MOF-74의 결정 격자는 변하지 않음을 확인할 수 있었다. 이는 MoS_x가 비결정성 구조(amorphous structure)이기 때문으로 판단된다. 도 8b를 참조하면, 열방법에 의하여 활성화된 Ni-MOF-74는 1662 cm^-1 에서 낮은 진동 시그널 강도를 갖고, 이는 Ni 자리 활성화 과정에서 용매 분자가 현저하게 제거되었기 때문이다. 또한, C-O (H) 결합이 1193 cm^-1의 진동 주파수로 나타나는 과정에서, C=O (-COOH)의 비대칭 및 대칭 신축진동(stretching vibrations) 주파수는 각각 1557 cm^-1 및 1417 cm^-1이였다. 도 8c에서는 질소 흡착등온선(N₂ sorption isotherm)으로 평가한 기공 특성을 평가하였다. Ni-MOF-74는 435㎡/g의 상대적으로 높은 표면적으로 나타내고, 이에 의하여 상기 Ni-MOF-74의 표면에 MoS_x가 용이하게 고정되도록 할 수 있다. 또한, 40% MoS_x/Ni-MOF-74의 표면적은 Ni-MOF-74보다 더 크게 나타났는데, 이는 표면에 고정된 MoSx의 분포에 기인하는 것으로 판단된다. Referring to FIG. 8a , the crystal phases of Ni-MOF-74 and 40% MoS _x /Ni-MOF-74 were confirmed by XRD spectra, the crystal planes of Ni-MOF-74 (2 -1 0) and (3 0 0) about 2 representing each

= 6.8 ^o and 11.7 ^o appeared, indicating that Ni-MOF-74 was well synthesized. 40% MoS _x /Ni-MOF-74 was equipped with MoS _x and the crystallinity was relatively decreased, but it was confirmed that the crystal lattice of Ni-MOF-74 was not changed as a whole. This is considered to be because MoS _x has an amorphous structure. Referring to FIG. 8b , Ni-MOF-74 activated by the thermal method has a low vibrational signal intensity at 1662 cm ⁻¹ , because solvent molecules are remarkably removed during the Ni site activation process. In addition, in the process where the CO (H) bond appeared with a vibration frequency of 1193 cm ^-1 , the asymmetric and symmetric stretching vibrations frequencies of C=O (-COOH) were 1557 cm ^-1 and 1417 cm ^-1 , respectively. . In FIG. 8c, the pore characteristics evaluated by the nitrogen adsorption isotherm (N ₂ sorption isotherm) were evaluated. Ni-MOF-74 exhibits a relatively high surface area of 435 m 2 /g, whereby MoS _x can be easily fixed to the surface of the Ni-MOF-74. In addition, the surface area of 40% MoS _x /Ni-MOF-74 was larger than that of Ni-MOF-74, which is considered to be due to the distribution of MoSx immobilized on the surface.

9 shows (a) Ni-MOF-74, (b) 20% MoS _x /Ni-MOF-74, (c) 40% MoS _x /Ni-MOF-74, (d) 60% MoS _x /Ni- SEM images of MOF-74, (e) 80% MoS _x /Ni-MOF-74, and (f) MoS _x .

Referring to FIG. 9 , it was confirmed that Ni-MOF-74 formed secondary particles having a flower-like structure by aggregating the primary particles after the formation of rod-shaped crystal primary particles. Referring to the form in which MoSx is gradually fixed on the surface of Ni-MOF-74, at 20% MoS _x /Ni-MOF-74, a part of the surface of Ni-MOF-74 is vacant, and MoS _x becomes Ni-MOF- It was confirmed that it was provided in 74. On the other hand, when the content of MoS _x was increased, it was confirmed that the Ni-MOF-74 crystal was fixed perpendicularly to the surface. On the other hand, when the content of MoS _x is excessively increased, it may interfere with the formation of the NiMoS phase, thereby reducing the electrocatalytic HER yield. In an embodiment of the present invention, 40% MoS _x /Ni-MOF-74 may be preferred.

10 is a TEM image of (a) and (d) Ni-MOF-74, (b) and (e) MoS _x , (c) and (f) 40% MoS _x /Ni-MOF-74, respectively.

Referring to FIG. 10 , it was confirmed that the size of the Ni-MOF-74 crystal was approximately 300 nm, and the diameter of MoS _x was 150 nm. In FIG. 10(c), it was confirmed that MoS _x was fixed to the surface of Ni-MOF-74. The HR-TEM image showed a lattice pattern of 0.197 nm representing the (5-10) plane of Ni-MOF-74, which means that the crystals of Ni-MOF-74 were maintained even after MoS _x was fixed on the surface ( 10(d), (f)). Here, since MoS _x has an amorphous structure, it did not appear in the HR-TEM image (Fig. 10(e)).

11 is an XPS spectrum of Ni-MOF-74 and 40% MoS _x /Ni-MOF-74, (a) is Ni 2 p, (b) is Mo 3 d and S 2 s, (c) is S 2 p is shown, respectively.

In FIG. 11, the XPS spectrum was confirmed to confirm the chemical state of Ni-MOF-74 and 40% MoS _x /Ni-MOF-74. 11 (a) shows the XPS spectrum of Ni 2p, two peaks appeared at 874.0.6 eV and 856.3 eV, respectively, indicating Ni ²⁺ 2p _1/2 and Ni ²⁺ 2p _3/2 . On the other hand, saturated Ni appears at 880.2 eV and 861.9 eV. This peak was also observed at 40% MoS _x /Ni-MOF-74, indicating that a stable Ni-MOF-74 structure was formed. In addition, two new small peaks at 871.6 eV and 853.7 eV are attributed to the presence of the NiMoS phase. The NiMoS phase is formed by the interaction between Ni open sites and S (or Mo) atoms in MoS _x . In FIG. 11(b), a peak was confirmed at 235.9 eV, 232.8 eV means the oxidation state of Mo ⁵⁺ , and the oxidation state of Mo ⁴⁺ 3d _3/2 and Mo ⁴⁺ 3d _5/2 is 231.9 eV, respectively. and 228.8 eV. The peaks of disulfide ions (S ₂ ^2- ) were 163.9 eV and 162.7 eV, and the peaks of divalent sulfide ions (S ^2- ) were 162.5 eV and 161.3 eV ( FIG. 11( c )).

Figure 12 is Ni-MOF-74 and 20-100% MoS _x /Ni-MOF-74 of (a) polarization curve, (b) Tafel slope (Tafel slope), (c) EIS (Electro-impedance spectroscopy) Niqui Nyquist plot, (d) A graph showing the cycle test after 2000 cycles of 40% MoS _x /Ni-MOF-74.

12, Ni-MOF-74, 20% MoS _x /Ni-MOF-74, 40% MoS _x /Ni-MOF-74, 60% MoS _x /Ni-MOF-74, 80% MoS _x /Ni-MOF -74, and HER electrocatalytic activity of MoS _x were shown. In addition, for comparison, hydrogen production performance was evaluated using a compatible Pt/C catalyst. 12( a ) shows a linear sweep voltammetry (LSV) plot. Currently, Pt is considered as the best catalyst for hydrogen production. The Pt/C electrode showed the lowest onset potential of ~ 0 mV, and Ni-MOF-74 showed the highest onset potential of 320 mV. On the other hand, it was confirmed that the catalytic activity of MoS _x /Co-MOF-74 in which MoS _x was immobilized on Ni-MOF-74 was greatly improved. In particular, catalysts with 20%, 40%, 60%, 80% MoS _x are 20% MoS _x /Ni-MOF-74, 40% MoS _x /Ni-MOF-74, 60% MoS _x /Ni-MOF -74 and 80% MoS _x /Ni-MOF-74 complexes exhibited an onset potential of 302, 117, 120, and 191 mV, respectively, whereas MoSx exhibited an onset potential of 153 mV. In particular, it was confirmed that 40% MoS _x /Ni-MOF-74 requires only a low overvoltage of 167mV to generate a current density of 10mA/cm2.

Fig. 12(b) shows the Tafel slope value of the catalyst by a linear plot of overvoltage versus log (current density). The Ni-MOF-74 catalyst exhibited the largest Tafel slope of 115.4 mV dec-1 due to its high charge transfer resistance, whereas 40% MoS _x /Ni-MOF-74 had the lowest Tafel slope of 53.1 mV dec-1, with hydrogen It means the fastest generation speed. 60% MoS _x /Ni-MOF-74 (60.3mV dec-1), 80% MoS _x /Ni-MOF-74 (60.7mV dec-1) showed a smaller Tafel slope than MoS _x . This means that 40% MoS _x /Ni-MOF-74 shows the highest yield in HER through electrochemical methods, since 40% MoS _x /Ni-MOF-74 contains two types of active sites. is judged as First, the NiMoS moiety reduced the free energy of hydrogen adsorption, and secondly, MoS _x grown on the Ni-MOF-74 template provided active centers for unsaturated Mo and S. In addition, the formation of the NiMoS phase increased the electrochemical surface area of the composite as determined in the double-layer capacitance (C _dl ). In particular, it can be seen that 40% MoS _x /Ni-MOF-74 at C _dl is 2.77 mF/cm 2 , whereas Ni-MOF-74 and MoS _x show low values of 0.26 mF/cm 2 and 0.91 mF/cm 2 , respectively. there was.

In general, the Tafel slope is related to the HER reaction rate and reaction mechanism. Based on the obtained Tafel gradient, it was confirmed that the generation of hydrogen when using the MoS _x /Ni-MOF-74 complex as a catalyst is formed by combining the Volmer reaction and the Heyrovsky reaction as shown by the following formulas (1) and (2). can

H ₃ O ⁺ + e ^- → H* + H ₂ O (1)

H ₃ O ⁺ + e ^- + H* → H ₂ + H ₂ O (2)

EIS measurement was performed to evaluate the HER rate, and was performed with an overvoltage of 200 mV in H ₂ SO ₄ (0.5 M) solution. Referring to FIG. 12( c ), an EIS Nyquist plot including an electric circuit including a series resistance (Rs), a charge transfer resistance (Rct) and a constant phase element (CPE) is shown. Referring to Table 3, Ni-MOF-74 exhibited a relatively large Rct of 8375 Ω, confirming that the hydrogen production yield was low. It was confirmed that the resistance decreased.

Sample R _S (Ω) R _ct (Ω) Ni-MOF-74 12.7 8375 20%MoS _x /Ni-MOF-74 14.6 289.2 40%MoS _x /Ni-MOF-74 16.5 40.4 60%MoS _x /Ni-MOF-74 16.6 59.6 80%MoS _x /Ni-MOF-74 16.7 79.3 MoS _x 16.4 125.0

40% MoS _x /Ni-MOF-74 exhibited lower electrical conductivity than MoSx with an Rct of 40.4 Ω, which is considered to be due to the appearance of the NiMoS phase. In addition, as a result of confirming the durability to confirm that the application is suitable for industrial use, the stability of 40% MoS _x /Ni-MOF-74 as an electrocatalyst was confirmed by the CV method as shown in FIG. 12(d). After 2000 cycles, the overvoltage (current density of 10 mA/cm 2 ) increased from 167 to 170 mV, which means that the catalytic activity was reduced, which is thought to be due to the decrease in the amount of S ₂ ^2- .

As described above, Ni-MOF-74 and MoS _x /Ni-MOF-74 composites could be successfully prepared by solvothermal synthesis, and their performance was confirmed by hydrogen generation by water electrolysis. 40% MoS _x /Ni-MOF-74 (575m2/g) showed a higher surface area than Ni-MOF-74 (435m2/g), and 40% MoS _x /Ni-MOF-74 had a Tafel slope 53mV dec It was confirmed that the most effective hydrogen production catalyst was found when 40wt% of MoS ₂ was included in the complex at -1 and the initiation potential of -114 mV. In addition, MoS _x /Ni-MOF-74 showed high stability even at 2000 cycles, which is thought to be due to the formation of the NiMoS phase and the large surface area due to reduced electrochemical surface area and hydrogen absorption.

Those of ordinary skill in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential features thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention. should be interpreted

Claims (13)

a body portion in which the first transition metal includes a metal-organic framework (MOF); and
A composite for a hydrogen production catalyst comprising a; a plurality of primary particles provided on the outer surface of the body portion and containing a second transition metal. According to claim 1,
The metal-organic framework is a MOF-74 system, and the first transition metal is nickel (Ni) or cobalt (Co). According to claim 1,
The second transition metal is a composite for a hydrogen generation catalyst consisting of a metal different from the first transition metal. 4. The method of claim 3,
The first transition metal is nickel (Ni) or cobalt (Co),
The second transition metal is molybdenum (Mo) or tungsten (W). According to claim 1,
The primary particles include MoS _x ,
The primary particles are provided to cover the outer surface of the body portion, the composite for hydrogen generation catalyst is provided so that at least a portion of the body portion is exposed to the outside. 6. The method of claim 5,
Based on 100 parts by weight of the body part, the primary particle is 20 parts by weight to 60 parts by weight of the hydrogen-generating catalyst composite. 6. The method of claim 5,
The body portion has crystal planes (2 −1 0) and (3 0 0) measured by XRD spectrum, and the primary particle is a composite for a hydrogen production catalyst consisting of an amorphous structure. According to claim 1,
When the first transition metal is cobalt (Co), the body portion has a rod shape. When the first transition metal is nickel (Ni), the body portion has a plurality of rod shapes. shape) is provided as secondary particles formed by agglomeration of primary particles,
The primary particles are nanoparticles (nanoparticles) vertically fixed (anchor) on the outer surface of the body portion for a hydrogen-generating catalyst composite. According to claim 1,
The starting potential by linear sweep voltammetry (LSV) is -280mV to -140mV when the first transition metal is Co, and 100mV to 350mV when the first transition metal is Ni. Hydrogen including Composites for production catalysts. According to claim 1,
The first transition metal is Co or Ni, the second transition metal is Mo, and the composite for the hydrogen production catalyst is a composite for a hydrogen production catalyst comprising 5 wt% to 40 wt% of a CoMoS phase or a NiMoS phase. According to claim 1,
The body portion has a specific surface area of 300 m / g to 500 m / g of a hydrogen-generating catalyst composite. preparing a body part by reacting it using a first solution containing a first transition metal at a first temperature and for a first time; and
The body part is mixed with a second solution containing a second transition metal, and a third solution is added to react for a second temperature and a second time to form a plurality of primary particles containing a second transition metal on the outer surface of the body part. Including; coating;
The metal-organic framework is MOF-74 based, and the first transition metal is nickel (Ni) or cobalt (Co). manufacturing method. 13. The method of claim 12,
The first solution is Co(NO ₃ ) ₂ .6H ₂ O or Ni(NO ₃ ) ₂ .6H ₂ O,
The first temperature is 80 ℃ to 120 ℃,
The first time is 20 to 30 hours,
The second solution is (NH ₄ ) ₂ MoS ₄ ,
The third solution is hydrazine hydrate,
The second temperature is 200 ℃ to 300 ℃,
The second time is a method for producing a complex for a hydrogen production catalyst that is 8 hours to 15 hours.

Images