KR20230052649A - Hydrocarbon manufacturing method and hydrocarbons manufactured using the same - Google Patents

Abstract

The present invention relates to a hydrocarbon manufacturing method and a hydrocarbon manufactured thereby, wherein the method includes the steps of: preparing a container; and forming a carbon-metal alloy by solid-phase mixing a carbon-based material and a metal catalyst in the container under a hydrogen gas atmosphere. The present invention exhibits the characteristics of a high reaction rate, selectivity and stability even at low temperatures.

Description

Hydrocarbon manufacturing method and hydrocarbons manufactured using the same}

It relates to a method for producing hydrocarbons and hydrocarbons produced using the same.

Carbon hydrogasification is widely applied in carbon-related important industries such as hydrocarbon synthesis, coal and biomass gasification, and exhaust gas treatment. However, the carbon hydrogasification reaction is the most difficult reaction among carbon-related reactions and is the slowest reaction at the actual operating temperature (at least 450 ℃), which is 8 times slower than the carbon oxidation reaction. From a thermodynamic point of view, the dissociation process of C-C bonds in the carbon matrix has a very high energy barrier, so high temperature activation is required to break it, but from the point of view of reaction equilibrium, the carbon hydrogasification reaction itself is an exothermic reaction and low temperature is advantageous. due to the tendency Therefore, there is still a need for a hydrocarbon production method capable of showing excellent reaction rate and selectivity at low temperatures.

An object of the present invention relates to a method for producing hydrocarbons, which includes forming a carbon-metal alloy by solid-phase mixing a carbon-based material and a metal catalyst under a hydrogen gas atmosphere, thereby showing excellent reaction rate and selectivity even at low temperatures. And to provide a hydrocarbon using the same.

According to one aspect, preparing a container; and forming a carbon-metal alloy by solid-phase mixing a carbon-based material and a metal catalyst in the container under a hydrogen gas atmosphere.

According to another aspect, a hydrocarbon produced according to the hydrocarbon production method is provided.

A method for producing a hydrocarbon according to one aspect includes forming a carbon-metal alloy by solid-phase mixing a carbon-based material and a metal catalyst under a hydrogen gas atmosphere, thereby exhibiting characteristics of high reaction rate, selectivity, and stability even at low temperatures.

1 is a result of measuring the production rate of hydrocarbon (CH ₄ ) according to the temperature with respect to Example 1-a, Comparative Example 1, and the control group.
2a and 2b show the result of measuring the gas composition according to gas chromatography for the gas product obtained in Example 1-a.
3a and 3b show the results of measuring the CH ₄ production rate and total amount of production in each cycle measured for five cycles for catalyst 1-a.
4 is a result of comparing hydrocarbon production rates for different metal catalysts.
FIG. 5A is a result of comparing hydrocarbon production rates for different carbon-based materials, and FIG. 5B shows Raman spectroscopic measurement results for each carbon-based material.
6 is a result showing the amount and production rate of CH ₄ for Examples 1-a-1 to 1-a-5 in which Co and carbon black have different loading ratios.
7 is a schematic summary of carbon dissociation models I to III.
8 is a diagram showing initial and final states of carbon dissociation models I to III for
9 is a diagram showing carbon dissociation energy barriers (eV) of carbon dissociation models I to III according to the DFT calculation method.
10 shows the results of measuring the radial distribution function (RDF) derived from extended X-ray absorption fine structure (EXAFS) for the intermediate sample of the hydrocarbon production method of the present invention.
11 shows high-resolution photoemission spectroscopy (PES) measurement results for C1s at hν = 350 eV for an intermediate sample of the hydrocarbon production method of the present disclosure.
12 shows the C K-edge X-ray absorption near edge structure (XANES) measurement results for the intermediate sample of the hydrocarbon production method of the present invention.
Figure 13 shows the X-ray diffraction pattern (XRD) measurement results for the intermediate sample of the hydrocarbon production method of the present application.
Figure 14 shows ^{the 59} Co internal field nuclear magnetic resonance (IF-NMR) measurement results for intermediate samples of the hydrocarbon production method of the present application.
Figure 15 shows ^{the 13} C IF-NMR measurement results under Co internal field for the intermediate sample of the hydrocarbon production method of the present application.

Since the present inventive concept described below can be applied with various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present creative idea to a specific embodiment, and should be understood to include all transformations, equivalents, or substitutes included in the technical scope of the present creative idea.

Terms used below are only used to describe specific embodiments, and are not intended to limit the present inventive idea. Singular expressions include plural expressions unless the context clearly dictates otherwise. Hereinafter, terms such as “comprise” or “have” are intended to indicate that there is a feature, number, step, operation, component, part, component, material, or combination thereof described in the specification, but one or the other It should be understood that the presence or addition of the above other features, numbers, steps, operations, components, parts, components, materials, or combinations thereof is not precluded.

Also, terms such as first and second may be used throughout the specification to describe various components, but the components should not be limited by the terms.

In the drawings, the thickness is enlarged or reduced to clearly express various layers and regions. Like reference numerals have been assigned to like parts throughout the specification. Throughout the specification, when a part such as a layer, film, region, plate, etc. is said to be "on" or "above" another part, this includes not only the case directly on top of the other part, but also the case where there is another part in the middle thereof. . Terms are used only to distinguish one component from another.

In the carbon hydrogasification reaction, which is a type of hydrocarbon manufacturing method, from a thermodynamic point of view, the dissociation process of the C-C bond in the carbon matrix has a very high energy barrier, and high temperature activation is required to break it. As it is an exothermic reaction, its application to a wide range of industrial/technical fields has been limited as it has the opposite tendency that low temperatures are advantageous. The present inventor relates to a hydrocarbon production method, which includes forming a carbon-metal alloy by solid-phase mixing a carbon-based material and a metal catalyst under a hydrogen gas atmosphere, thereby providing a hydrocarbon production method that exhibits excellent reaction rate and selectivity even at low temperatures. found, and completed the present invention through research in this respect. The hydrocarbon production method according to one embodiment of the present invention showed a high hydrocarbon (CH ₄ ) production rate (40°C, 117,000 μl g ^-1 s ^-1 ) and excellent selectivity (99.8% of CH ₄ ) even under low temperature conditions.

Hereinafter, a hydrocarbon production method according to an aspect of the present invention will be described in detail.

The hydrocarbon production method includes preparing a container; and forming a carbon-metal alloy by solid-phase mixing a carbon-based material and a metal catalyst in the container under a hydrogen gas atmosphere.

For example, through DFT calculations and EXAFS-derived RDF, PES, and XANES measurements of samples in which carbon black as a carbon-based material and cobalt as a metal catalyst were mixed in a solid state under a hydrogen gas atmosphere, carbon-metal alloys (cobalt carbides) formation can be seen.

According to one embodiment, the solid state mixing includes first solid state mixing and second solid state mixing, and mixing speeds of the first solid state mixing and the second solid state mixing may be the same or different from each other.

According to one embodiment, the solid-phase mixing may be performed through ball-milling.

According to one embodiment, the step of forming the carbon-metal alloy may be performed at 525°C or lower. For example, the step of forming the carbon-metal alloy may be performed at 10°C or more and 100°C or less. This corresponds to a point different from the conventional hydrocarbon manufacturing method, which requires a high-temperature heat treatment process.

According to one embodiment, the forming of the carbon-metal alloy may further include an organic solvent in the container. That is, the method may include forming a carbon-metal alloy by solid-phase mixing a carbon-based material, a metal catalyst, and an organic solvent in the container under a hydrogen gas atmosphere.

According to one embodiment, the organic solvent may be a saturated or unsaturated aliphatic or alicyclic hydrocarbon, aromatic hydrocarbon, alcohol, glycol, halogenated hydrocarbon, ketone, ester, ether, glycol ether, or any combination thereof.

For example, the organic solvent is tetrahydrofuran (THF), acetonitrile, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF) , 2-propanol, toluene, benzene, chlorobenzene, 1,2-dichlorobenzene, or any combination thereof.

According to one embodiment, the solid phase mixing may be performed for 1 hour or more and 30 hours or less.

According to one embodiment, the ball-milling is performed at 200 r.p.m. over 550 r.p.m. It can be performed at the following rotational speeds. For example, the ball-milling is performed at 300 r.p.m. over 450 r.p.m. can be

According to one embodiment, the speed of the ball during the ball-milling may be performed at 0.1 m/s or more and 20 m/s or less.

According to one embodiment, the rotational speed of the ball-milling may be maintained constant or varied. For example, it can be run at a speed of 350 r.p.m. for the first 15 hours and then 400 r.p.m. for the next 15 hours.

According to one embodiment, the ball-milling includes a first ball-milling and a second ball-milling, and rotation speeds of the first ball-milling and the second ball-milling may be the same as or different from each other.

According to one embodiment, the carbon-based material may be charcoal, carbon black, graphite, graphene, or any combination thereof.

According to one embodiment, the I _D /I _G value of the carbon-based material may be greater than zero. Here, I _D means a peak intensity at 1350 cm ^-1 in a graph obtained by Raman spectroscopy for a carbon-based material, and I _G means a peak intensity at 1580 cm ^-1 .

According to one embodiment, the I _2D /I _G value of the carbon-based material may be greater than 0 and less than 1. Here, I _2D means a peak intensity at 2700 cm ⁻¹ in a graph obtained by Raman spectroscopy for a carbon-based material, and I _G is as defined above.

According to one embodiment, the carbon-based material may include a Klein carbon-carbon bond (Klein C-C bond). The 'cline carbon-carbon bond' refers to a bond between a carbon atom additionally bonded to a zigzag edge in a carbon-based material and a neighboring carbon atom, and carbon in the form shown in the subscript 2 model of FIG. -means a carbon bond.

According to one embodiment, the metal catalyst may be Fe, Co, Ni, Cu, or any combination thereof.

According to one embodiment, the metal catalyst may be Co.

According to one embodiment, the metal catalyst may include Co(111) atoms.

According to one embodiment, the metal catalyst may include defects. The defects may be generated by solid phase mixing.

According to one embodiment, the content of the carbon-based material may be 1 part by weight or more and 20 parts by weight or less based on a total of 100 parts by weight of the carbon-based material and the metal catalyst.

According to one embodiment, the carbon-metal alloy may include cobalt-carbide.

According to one embodiment, the carbon-metal alloy may include Co ₃ C.

For example, XANES XRD and IF-NMR of a sample in which carbon black as a carbon-based material and cobalt as a metal catalyst are mixed in a solid state under a hydrogen gas atmosphere. Through the measurement, it can be confirmed that Co ₃ C is included.

According to one embodiment, the carbon-metal alloy may include defects.

According to one embodiment, the pressure of hydrogen gas in the vessel may be about 1 to 10 bar.

According to one embodiment, the forming of the carbon-metal alloy may include preparing a carbon-based material and a metal catalyst in an inert atmosphere, and replacing the inert atmosphere with a hydrogen gas atmosphere.

According to one embodiment, the forming of the carbon-metal alloy may include dissociating carbon from the carbon-based material.

According to one embodiment, the step of dissociating the carbon may include a step of dissociating the carbon while breaking a Klein C-C bond of the carbon-based material.

According to one embodiment, the forming of the carbon-metal alloy may include forming a covalent bond between carbon derived from the carbon-based material and a metal catalyst.

According to an embodiment, carbon derived from a carbon-based material may form a carbon-metal alloy by forming a covalent bond with a defect in a metal catalyst.

For example, the forming of the carbon-metal alloy may include preparing a carbon-based material and a metal catalyst in an inert atmosphere, replacing the inert atmosphere with a hydrogen gas atmosphere, dissociating carbon from the carbon-based material, The step of forming a covalent bond between carbon derived from the carbon-based material and the metal catalyst may be performed, but is not limited thereto. That is, any of these steps may be omitted or the order of each other may be reversed, and new steps may be added.

According to one embodiment, the forming of the carbon-metal alloy may include performing a hydrogenation reaction.

According to one embodiment, the step of conducting the hydrogenation reaction may be performed at 525° C. or lower. For example, the step in which the hydrogenation reaction proceeds may be performed at 10° C. or more and 100° C. or less.

According to one embodiment, the step of conducting the hydrogenation reaction may include a step of dissociating activated carbon atoms from the carbon-metal alloy.

According to one embodiment, the step of conducting the hydrogenation reaction may include generating hydrocarbons by reacting hydrogen gas with activated carbon atoms derived from the carbon-metal alloy.

According to one embodiment, the hydrocarbon within this specification may be methane (CH ₄ ).

According to one embodiment, the container may be a ball-mill container.

According to another aspect, a hydrocarbon produced according to the hydrocarbon production method described above may be provided.

Hereinafter, synthesis examples and examples will be described in more detail with respect to multiple complex compounds according to one embodiment of the present invention.

Hereinafter, synthesis examples and examples will be described in more detail with respect to multiple complex compounds according to one embodiment of the present invention.

Raw material

Fe [99.9+% (metals basis), <10 μm], Co [99.8% (metals basis), spherical, -100+325 mesh], Ni [99.9% (metals basis), APS 2.2-3.0 μm], graphite [99.9995% (metals basis), -100 mesh] and carbon black (99.9+%, acetylene, 100% compressed) were purchased from Alfa Aesar. Cu [99%, +45 μm particle size (2% max)] and charcoal (untreated, granular, ≤5 mm) were purchased from Sigma-Aldrich.

Preparation Example A: Activation Step of Hydrocarbon Production Catalyst

A metal catalyst, carbon-based material and WC balls (Φ = 5 mm, 1000 g) were loaded into a ball-mill container (250 ml) in a glove box under an argon gas (99.999%, KOSEM Corp., Korea) atmosphere. After taking the ball-mill container out of the glove box, argon gas in the container was replaced with pure hydrogen gas (99.999%, Daesung Industrial Gases Co. LTD) using a vacuum pump. After several charge/discharge cycles, the argon gas in the container was completely removed. Thereafter, a ball-mill was performed for 12 hours at a rotational speed of 300 r.p.m. under a hydrogen gas atmosphere of 8 bar to activate the metal catalyst and the carbon-based material to prepare a hydrocarbon generating catalyst.

Preparation Example 1: Preparation of Catalysts 1-a to 1-d, 2-a and 3-a

The following catalysts 1-a to 1- d, 2-a and 3-a were prepared.

Metal Catalyst/ Loading (g) Carbon-based catalyst/loading amount (g) Catalyst 1-a Co/25.3 carbon black/3 Catalyst 1-b Fe/24 carbon black/3 Catalyst 1-c Ni/25.2 carbon black/3 catalyst 1-d Cu/27.3 carbon black/3 Catalyst 2-a Co/25.3 Charcoal/3 Catalyst 3-a Co/25.3 graphite/3

[Example]

Examples 1-a to 1-d: Hydrocarbon production method according to solid phase mixing

For the catalysts 1-a to 1-d prepared according to Preparation Example 1, the gas product in each vessel was completely evacuated for at least 2 hours, and the ball was balled for 5 minutes at a rotational speed of 400 r.p.m. under a hydrogen gas atmosphere of 8 bar. - Hydrocarbons were prepared while milling, respectively, corresponding to Examples 1-a to 1-d.

Comparative Example 1: Hydrocarbon production method according to heat treatment method

Load 25.3 g of Co and 3 g of carbon black into a quartz tube (6 mm inner diameter) in a glove box under an argon gas (99.999%, KOSEM Corp., Korea) atmosphere, and parafilm the two ends before removing the loaded quartz tube from the glove box. sealed with. Thereafter, the quartz tube is installed in a fixed bed reactor under an argon gas atmosphere, and finally, the argon gas is replaced with hydrogen gas, and the argon gas remaining in the tube is heated for 30 minutes with a hydrogen gas flow of 10 SSCM (Standard Cubic Centimeters Per Minute). washed while. The fixed bed reactor was heated to 600° C. at a ramp of 2.48° C. per minute in a hydrogen gas flow of 10 SSCM to produce hydrocarbons.

Control: treatment without metal catalyst

A hydrocarbon generating catalyst was prepared in the same manner as in Preparation Example A, except that no metal catalyst was used in Preparation Example A and 3 g of carbon black was used as the carbon-based material. Then, in a glove box under an argon gas (99.999%, KOSEM Corp., Korea) atmosphere, 3 g of the activated hydrocarbon generating catalyst was loaded into a quartz tube (internal diameter of 6 mm), and the loaded quartz tube was removed from the glove box. The ends were sealed with parafilm. Thereafter, the quartz tube is installed in a fixed bed reactor under an argon gas atmosphere, and finally, the argon gas is replaced with hydrogen gas, and the argon gas remaining in the tube is heated for 30 minutes with a hydrogen gas flow of 10 SSCM (Standard Cubic Centimeters Per Minute). After washing for a while, the fixed bed reactor was heated to 600° C. at a ramp of 2.48° C. per minute in a hydrogen gas flow of 10 SSCM to produce hydrocarbons.

[Evaluation Example 1a: Reaction Rate Comparison]

(Assessment Methods)

For Example 1-a, Comparative Example 1, and the control group, the production rate of hydrocarbon (CH ₄ ) according to temperature was measured, and the results are shown in FIG. 1 .

(Evaluation results)

Through Figure 1, it can be seen that Example 1-a shows a remarkably high production rate (40 ℃, 117,000 μl g ^-1 s ^-1 ) compared to Comparative Example 1 and the control group under low temperature conditions, which is 600 It can be seen that this corresponds to a remarkably high reaction rate even when compared to the production rate of 5 μlg ^-1 s ^-1 of Comparative Example 1 at °C.

[Evaluation Example 1b: Selectivity Comparison]

(Assessment Methods)

The composition of the gas product obtained in Example 1-a was measured using gas chromatography (GC, 7890B, Agilent), and the result is shown in FIG. 2a, and a magnification of 500 times is shown in FIG. 2b.

(Evaluation results)

2a and 2b, it can be confirmed that the gaseous product obtained in Example 1-a contains 99.8% of CH ₄ . This is a significantly higher value compared to that of the gaseous product obtained in Comparative Example 1 containing 80% of CH ₄ (600° C., equilibrium state, not shown), and Example 1-a has excellent selectivity compared to Comparative Example 1. It can be seen that it is a hydrocarbon production method with

[Evaluation Example 1c: Stability Test]

(Assessment Methods)

Regarding Example 1-a to which catalyst 1-a was applied, after the input carbon black was completely hydrogenated, the process of adding 3 g of carbon black was repeated to complete one cycle, and CH ₄ of each cycle for a total of five cycles The production rate and total production amount were confirmed and shown in FIGS. 3a and 3b, respectively.

(Evaluation results)

3a and 3b, it can be seen that the rate and amount of CH ₄ produced in Catalyst 1-a are maintained constant even when the number of hydrocarbon production cycles increases.

[Evaluation Example 2: Comparison of hydrocarbon production rates according to metal catalysts]

(Assessment Methods)

For Examples 1-a to 1-d, average hydrocarbon (CH ₄ ) production rates at 40° C. were measured and shown in FIG. 4 .

(Evaluation results)

4, it can be confirmed that CH ₄ is produced in all of Examples 1-a to 1-d, and Example 1-d (Cu) < Example 1-b (Fe) < Example 1-c (Ni) < It can be confirmed that the CH ₄ production rate increases in the order of Example 1-a (Co). This is a tendency different from the heat treatment method in which Ni has the highest reaction rate, and it can be seen that the hydrocarbon production method according to the present application follows a different reaction path from the hydrocarbon production method (Comparative Example 1) by the heat treatment method.

Examples 1-a to 3-a

For the catalysts 1-a to 3-a prepared according to Preparation Example 1, the gas product in each vessel was completely evacuated for at least 2 hours, and the ball was balled for 5 minutes at a rotation speed of 400 r.p.m. under a hydrogen gas atmosphere of 8 bar. -Proceeding with the mill to produce hydrocarbons, corresponding to Examples 1-a to 3-a, respectively.

[Evaluation Example 3a: Comparison of hydrocarbon production rates according to carbon-based materials]

(Assessment Methods)

For Examples 1-a to 3-a, average hydrocarbon (CH ₄ ) production rates at 40° C. were measured and shown in FIG. 5A.

(Evaluation results)

5a, it can be confirmed that CH ₄ is generated in all of Examples 1-a to 3-a, Example 3-a (graphite) < Example 1-a (carbon black) < Example 2-a ( It can be seen that the CH ₄ production rate increases in the order of charcoal).

[Evaluation Example 3b: Raman spectroscopy measurement for each carbon-based material]

(Assessment Methods)

The results of Raman spectroscopy (WITec Alpha300R equipment with a laser wavelength of 532 nm) were measured for carbon black, charcoal, and graphite used as the carbon-based materials of Catalysts 1-a to 3-a and are shown in FIG. 5B.

(Evaluation results)

5b, it can be seen that the crystallinity (I _D /I _G value is inversely proportional to the crystallinity) increases in the order of charcoal < carbon black < graphite, which is opposite to the reaction rate trend of FIG. 5a. applicable That is, as the crystallinity of the carbon-based material decreases, the reactivity increases, and this can be seen because the dissociation of carbon in the carbon-based material is more advantageous as the crystallinity decreases.

Preparation Example 2: Preparation of Catalysts 1-a-1 to 1-a-5

Catalyst 1-a- 1 to 1-a-5 were prepared.

Loading amount of Co (g) Loading amount of carbon black (g) Catalyst 1-a-1 12.7 6.0 Catalyst 1-a-2 16.9 5.0 Catalyst 1-a-3 21.1 4.0 Catalyst 1-a-4 25.3 3.0 Catalyst 1-a-5 29.5 2.0

Examples 1-a-1 to 1-a-5

The catalysts 1-a-1 to 1-a-5 prepared according to Preparation Example 2 were ball-milled for 7 minutes at a rotational speed of 300 r.p.m. to produce hydrocarbons, respectively. 1 to Examples 1-a-5.

[Evaluation Example 4: Measurement of hydrocarbon production rate according to loading ratio]

(Assessment Methods)

The amount and rate of CH ₄ produced according to Examples 1-a-1 to 1-a-5 are shown in FIG. 6 .

(Evaluation results)

It can be seen from FIG. 6 that Example 1-a-3 produced the largest amount of CH ₄ and Example 1-a-4 produced the highest amount of CH ₄ .

[Evaluation Example 5: DFT Calculation]

An approximate summary of the carbon dissociation models I to III for DFT (density functional theory) calculation of the carbon dissociation process for investigating the reaction pathway of the hydrocarbon production method of the present application is shown in FIG. 7, and the carbon dissociation models I to III The initial state and the final state are shown in FIG. 8 .

(Description of Figs. 7 and 8)

I, carbon dissociation without catalyst.

II, carbon dissociation when the carbon is not in contact with the Co catalyst.

III, carbon dissociation when carbon fragments are in close contact with the Co catalyst.

Superscripts 1 and 2 denote the defect-free model (separation of one carbon atom by breaking two conjugated C-C bonds) and defect model (one Klein C-C bond at the edge), respectively. When Co catalysts are present, subscripts 1 and 2 additionally denote Co(111) extended surfaces and defects, respectively.

(Additional description of FIG. 8)

blue: cobalt atoms

gray: carbon atoms

(calculation condition)

All spin-free calculations for the carbon dissociation models I to III were performed using the Vienna ab initio simulation package (VASP). The electron-ion interaction was described based on the Projector-Augmented Wave (PAW) method, and the exchange and correlation functions were used by the Perdew-Burke-Ernzerhof (PBE) function in the generalized gradient method (GGA). A cutoff energy of 400 eV was adopted for the plane wave basis set, which produces a total energy convergence of less than 1 meV per atom. A vacuum width of 15 Å was added to avoid interaction between the two periodic units. Climbing image nudged elastic band (CINEB) method was used for transition state search and energy barrier determination.

carbon dissociation model

All carbon dissociation calculations were performed in Co(111), and the Co(111) surface was modeled through a p(3 × 3) unit cell with 4 layers of Co slabs throughout the DFT calculations. The bottom two Co layers were fixed in bulk position, and the top two Co layers were fully relaxed. The K-point was set to 6 × 6 × 1, and a larger model was used for carbon fragments adsorbed on the Co(111) surface, where the p(4 × 4) unit cell had a K-point of 4 × 4 × 1 was adopted as a point. In the graphene model, the K-point was set to 6 × 6 × 6, and Co vacancies were placed on top of Co (111) in the defect model. The defect-free model uses a graphene zigzag edge, and the defect model uses a Klein edge. The Klein edge means an edge in which carbon atoms are additionally bonded to the zigzag edge.

(Calculation result)

Carbon dissociation energy barriers (eV) of carbon dissociation models I to III calculated by the above-described DFT calculation method are shown in Table 3 and FIG. 9 below.

carbon dissociation model Defect Model (1)
(Zigzag edge) Defect Model (2)
(Klein edge) model I
(when Co does not exist) 7.4eV 3.8eV Model II
(When carbon is not in contact with Co) 7.4eV 3.8eV Model III
(when carbon is in contact with the Co (111) extended surface) 2.3eV 0.6eV

As can be seen in Table 3 and FIG. 9, in the carbon dissociation model, when carbon is in contact with the Co (111) extended surface and has defects (model III ₂ ), the energy barrier value for carbon dissociation is 0.6 eV for the hydrogenation reaction. It can be seen that it is lower than the energy barrier value of 0.9 eV. The above results support that the hydrocarbon production method of the present invention, which has a high reaction rate even at room temperature, proceeds through an intermediate of a carbon-metal alloy in which defects in contact between carbon and Co (111) extended surfaces exist.

[Evaluation Example 6: Intermediate Analysis]

Preparation Example 3: for intermediate analysis preparation of samples

In a glove box under an argon gas (99.999%, KOSEM Corp., Korea) atmosphere, 25.3 g of Co granules, 3 g of graphite, and ZrO ₂ balls (Φ = 5 mm, 423 g) were loaded into a ball-mill container (250 ml). After taking the ball-mill container out of the glove box, argon gas in the container was replaced with 8 bar pure hydrogen gas (99.999%, Daesung Industrial Gases Co. LTD) using a vacuum pump. Thereafter, a ball-mill was performed for 15 hours at a rotation speed of 400 rpm under a hydrogen gas atmosphere of 8 bar to activate the metal catalyst and carbon-based material, and then a rotation speed of 400 rpm for 15 hours in a hydrogen gas atmosphere of 8 bar. produced additional hydrocarbons. Thereafter, the sample in the ball-mill container was taken out of the glove box to prepare a sample for intermediate analysis.

EXAFS-derived radical distribution function (RDF)

(Assessment Methods)

Sampling of the intermediate analysis sample prepared by Preparation Example 3 for EXAFS measurement was performed in a glove box, the sample was sealed with a tape to prevent oxidation, and the sample was measured immediately after taking it out of the glove box. EXAFS was recorded on a 6D beamline in transmission mode at the Pohang Accelerator Laboratory (PAL), South Korea. RDF data was analyzed using Athena software, and the results are shown in FIG. 10 .

(Evaluation results)

Through the EXAFS-derived RDF of FIG. 10, it can be seen that the Co-C bond exists at 1.3 Å.

Photoemission spectroscopy (PES) and X-ray absorption near edge structure (XANES)

(Assessment Methods)

PES and XANES to study the chemical state were performed at the 4D PES beamline, Pohang Light Source (PLS), Pohang Accelerator Laboratory (PAL), Korea. The sample for analysis of the intermediate produced by Preparation Example 3 was not exposed to air during the entire process and was loaded into a vacuum chamber through an inert sample transfer technique. The prepared sample is first packed in a vacuum-sealed container in a glove box, then the container is unpacked in an N ₂ overflow glove tube directly connected to the load lock chamber, and the analysis is performed using a light emission electron analyzer (R3000, Scienta Omicron, Sweden) and was recorded with an X-ray absorption spectroscopy detector at room temperature at a pressure of 4 × 10 ^-10 Torr or higher. PES spectra were taken at hv = 350 eV from a synchrotron radiation source, and XANES spectra were obtained in total electron yield (TEY) mode. All spectra were normalized to the incident photon flux. The results of the PES spectrum are shown in FIG. 11 and the XANES spectrum results are shown in FIG. 12 .

(Evaluation results)

It can be seen from the C1s core level spectrum of FIG. 11 and the C K-edge XANES of FIG. 12 that cobalt carbide is present.

X-ray powder diffraction (XRD)

(Assessment Methods)

Sampling of the sample for observation of the intermediate produced by Preparation Example 3 for XRD measurement was performed in a glove box, the sample was sealed with a tape to prevent oxidation, and the sample was measured immediately after taking it out of the glove box. 13.

(Evaluation results)

Through FIG. 13, it can be confirmed that some Co ₃ C carbides were involved in the hydrocarbon production process, and it can be seen that the broad and weak peaks have poor crystallinity due to the occurrence of defects.

Preparation Example 4: For IF-NMR analysis ¹³ Preparation of C-labeled samples

Co granules 12.7 g, ¹³ C (99 at.% ¹³ C, Sigma-Aldrich) 1 g, and ZrO ₂ balls (Φ = 5 mm, 423 g) were balled in a glove box under an argon gas (99.999%, KOSEM Corp., Korea) atmosphere. - Loaded into a mill container (250ml). After the ball-mill container was taken out of the glove box, argon gas in the container was replaced with 4 bar pure hydrogen gas (99.999%, Daesung Industrial Gases Co. LTD) using a vacuum pump. Thereafter, a ball-mill was performed for 12 hours at a rotation speed of 350 rpm under a hydrogen gas atmosphere of 8 bar to activate the metal catalyst and carbon-based material, and then a rotation speed of 350 rpm for 15 minutes under a hydrogen gas atmosphere of 3 bar. produced additional hydrocarbons.

Finally, the gas mixture in the ball-mill container was emptied, and the ¹³ C labeled sample contained therein was taken out of the glove box to prepare a ¹³ C labeled sample.

Internal field nuclear magnetic resonance (IF-NMR)

(Assessment Methods)

Prior to IF-NMR analysis, the sample prepared in Preparation Example 4 was first placed in a 5 mm NMR glass tube of a glove box protected with argon gas, then sealed in an NMR tube with a silicon tube and taken out of the glove box. Finally, the NMR tube was evacuated with argon gas and sealed with a blow torch.

IF-NMR was measured point by point with frequency steps between 0.5 and 2 MHz, and the spectral intensity at each frequency corresponds to the integral of the spin echo signal. The spin-echo sequence consisted of two identical radio frequency (RF) pulses of 1 μs with an inter-pulse delay of 8 μs at a repetition rate of 100 Hz, and the experiment was performed using two different spectrometers (TECMAG Scout and Bruker Avance III) due to the very broad nature of the spectra. ) and at ambient temperature (20 °C) using different probes. To obtain quantitative spectra, intensities were obtained at optimal excitation powers and corrected for the classical 1/ω^ ² factor and the T2 spin-spin relaxation time. ⁵⁹ Co IF-NMR results are shown in FIG. 14, and ¹³ C IF-NMR results are shown in FIG. 15.

(Evaluation results)

14, ^{the 59} Co IF-NMR 214 MHz peak shows that metallic Co is characterized by the fcc structure (22), and the broadened fcc Co peak indicates that the hydrocarbon production catalyst is nano-sized or largely amorphous due to high-density defects. As can be seen, this coincides with the trend of the XRD pattern of FIG. 10. In addition, it can be seen through the peak at 75 MHz that the carbide is mostly composed of Co ₃ C, and some of the carbon atoms are present dissolved in the fcc Co [Co (C ) solid solution, about 180 MHz] lattice.

Through FIG. 15, it can be confirmed that a strong signal is observed around 6.5 MHz, which corresponds to a peak corresponding to Co ₃ C. Therefore, it can be seen that Co ₃ C exists as a major intermediate in the hydrocarbon production method of the present application.

In conclusion, according to the above-described Examples and Comparative Examples, the hydrocarbon production method of the present application has a high hydrocarbon (CH ₄ ) production rate (40 ℃, 117,000 μl g ^-1 s ^-1 ), and it was confirmed that the gas product obtained by the above preparation method contained 99.8% of CH ₄ , indicating that it had excellent selectivity. In addition, even if the cycle is repeated, the stability of the hydrocarbon production catalyst of the present application was also confirmed by confirming that it had the same hydrocarbon (CH ₄ ) production rate and production amount. Therefore, the hydrocarbon production method of the present application corresponds to a production method showing high reaction rate, selectivity, and stability.

In addition, it can be confirmed that hydrocarbons (CH ₄ ) are generated even when various metal catalysts and carbon-based materials are applied at various loading ratios, and different reaction pathways are obtained through the fact that they show a different tendency from hydrocarbon production methods by conventional heat treatment methods. It can be seen that the reaction proceeds through In this regard, through DFT calculation, EXAFS-derived RDF, PES, XANES, XRD and IF-NMR, the preparation method of the present application is a process in which a metal catalyst and a carbon-based material are mixed in a solid phase (eg, ball-mill) It can be seen that by including the intermediate (Co ₃ C) of the carbon-metal alloy in, as mentioned above, the reaction rate and selectivity related to hydrocarbon production are improved.

Therefore, the hydrocarbon production method of the present application is a production method having high reaction rate, selectivity, and stability even at low temperatures, and shows that it can be used in various industries related to carbon that can be immediately used in industrial applications.

In the above, preferred embodiments according to the present invention have been described with reference to drawings and embodiments, but this is only exemplary, and those skilled in the art can make various modifications and equivalent other implementations therefrom. will be able to understand Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims (27)

Preparing a container; and
Forming a carbon-metal alloy by solid-phase mixing a carbon-based material and a metal catalyst in a hydrogen gas atmosphere in the container. According to claim 1,
Wherein the step of forming the carbon-metal alloy is performed at 525° C. or less. According to claim 1,
The step of forming the carbon-metal alloy is carried out at 10 ° C. or more and 100 ° C. or less, hydrocarbon production method. According to claim 1,
The solid phase mixing is performed for 1 hour or more and 30 hours or less, hydrocarbon production method. According to claim 1,
The solid-state mixing is performed through ball-milling, hydrocarbon production method. According to claim 5,
The ball-milling is performed at a rotational speed of 200 rpm or more and 550 rpm or less. According to claim 5,
The speed of the ball during the ball-milling is 0.1 m / s or more and 20 m / s or less, hydrocarbon production method. According to claim 1,
The carbon-based material is charcoal, carbon black, graphite, graphene, or any combination thereof. According to claim 1,
The hydrocarbon production method, wherein the I _D /I _G value of the carbon-based material is greater than zero. According to claim 1,
The hydrocarbon production method, wherein the carbon-based material has an I _2D /I _G value greater than 0 and less than 1. According to claim 1,
The carbon-based material includes a Klein carbon-carbon bond (Klein CC bond). According to claim 1,
Wherein the metal catalyst is Fe, Co, Ni, Cu, or any combination thereof. According to claim 1,
The metal catalyst is Co, hydrocarbon production method. According to claim 1,
Wherein the metal catalyst comprises Co (111) atoms. According to claim 1,
The method of claim 1, wherein the metal catalyst comprises a defect. According to claim 1,
The content of the carbon-based material is 5 parts by weight or more and 20 parts by weight or less, based on a total of 100 parts by weight of the carbon-based material and the metal catalyst. According to claim 1,
Wherein the carbon-metal alloy comprises cobalt-carbide. According to claim 1,
The method of claim 1, wherein the carbon-metal alloy comprises Co ₃ C. According to claim 1,
The pressure of hydrogen gas in the vessel is 1 bar or more and 10 bar or less, hydrocarbon production method. According to claim 1,
The hydrocarbon is methane (CH ₄ ), hydrocarbon production method. According to claim 1,
The step of forming the carbon-metal alloy comprises preparing the carbon-based material and the metal catalyst in an inert atmosphere, and replacing the inert atmosphere with a hydrogen gas atmosphere. According to claim 1,
Wherein the step of forming the carbon-metal alloy comprises dissociating carbon from the carbon-based material. According to claim 1,
The step of forming the carbon-metal alloy comprises forming a covalent bond between carbon derived from the carbon-based material and the metal catalyst. According to claim 1,
Wherein the step of forming the carbon-metal alloy comprises a step in which a hydrogenation reaction proceeds. According to claim 24,
Wherein the hydrogenation reaction proceeds comprises dissociating active carbon atoms from the carbon-metal alloy. The method of claim 24,
Wherein the step of conducting the hydrogenation reaction comprises generating a hydrocarbon by reacting an activated carbon atom derived from the carbon-metal alloy with hydrogen gas. A hydrocarbon produced by the hydrocarbon production method according to any one of claims 1 to 26.

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