KR20210085486A - Current collector for reduction apparatus of carbon dioxide, reduction apparatus of carbon dioxide comprising the same, and reducing method of carbon dioxide using the same - Google Patents

Abstract

The present invention relates to a current collector used for an apparatus for reducing carbon dioxide, an apparatus for reducing carbon dioxide comprising the same, and a method for reducing carbon dioxide using the same. The current collector of the present invention comprises, as a current collector which is used in an apparatus for reducing carbon dioxide and has a plate shape, a body part and a protruding part integrated with the body part. According to the present invention, reaction stability during reduction of carbon dioxide can be improved.

Description

Current collector for reduction apparatus of carbon dioxide, reduction apparatus of carbon dioxide comprising the same, and reducing method of carbon dioxide using the same}

The present invention relates to a current collector for use in a carbon dioxide reduction device, a carbon dioxide reduction device including the same, and a method for reducing carbon dioxide using the same.

Recently, a large amount of carbon dioxide emitted into the atmosphere due to rapid industrialization and economic activities increases the greenhouse effect and raises the temperature of the surface or lower atmosphere, causing global warming and climate change. As a technology for separating and recovering such carbon dioxide, a technique for recovering carbon dioxide using a physicochemical absorption method, an adsorption method, a membrane separation method, etc. In addition, since carbon dioxide corresponds to a carbon compound abundantly present on earth, a catalytic method, an electrochemical method, a biological conversion method for effectively activating carbon dioxide to convert it into a useful organic substance and using it as an energy source or a source of carbon required for organic synthesis Techniques for converting into a form of renewable energy such as photochemical methods and photochemical methods are also known.

Since the technology for converting carbon dioxide into useful compounds is a technology for converting the most stable carbon dioxide among carbon compounds into other useful compounds, input of energy is essential. In addition, the establishment of the relevant reaction is essential for effective conversion. The technology of reducing carbon dioxide into methane, ethane, methanol, ethanol, n-propanol, allyl alcohol, glycolaldehyde, acetaldehyde, acetate, ethylene glycol, propionaldehyde, acetone, hydroxyacetone, formaldehyde, formate, etc. Most of them are performed using planar electrodes in H-cell. Here, the planar electrode is an electrode without gas channels, such as a plate, sheet, or rotating disk-shaped electrode. Therefore, when a flat electrode is used, carbon dioxide is dissolved in the liquid electrolyte through bubbling, and the dissolved carbon dioxide diffuses through a long distance along the electrode surface. Therefore, the technique using the flat electrode as described above has a low current density due to low solubility of carbon dioxide, and thus has a problem of low efficiency.

Accordingly, a cell shape using gas diffusion electrodes (GDE) that allows gaseous carbon dioxide to be directly injected into the electrode has been developed, and an innovative technology in which a high concentration of carbon dioxide is used on a catalyst has been developed. As such a gas diffusion electrode was introduced, a reaction having a current density of less than ^{10 mA·cm -2} was improved to have a current density of ^{several tens of mA·cm -2 by bubbling carbon dioxide.}

However, the above reaction of converting carbon dioxide into a high-energy compound through an electrochemical reaction simultaneously causes a hydrogenation reaction. As described above, since the hydrogen evolution reaction at the anode and the reduction reaction at the cathode compete with each other, the reaction must be carried out at a relatively large negative potential. A study to increase the efficiency of voltage and potential and improve the selectivity for reduction products of carbon dioxide is continuing.

Accordingly, the inventors of the present invention while conducting intensive research to improve the efficiency of the carbon dioxide reduction device using the GDE electrode,

The present invention was completed by developing an apparatus capable of further improving the reaction stability and reduction efficiency of the carbon dioxide reduction apparatus using GDE.

An object of the present invention is to provide a carbon dioxide reduction device for improving the reaction stability of carbon dioxide reduction.

Specifically, an object of the present invention is to provide a current collector for inducing a stable electrochemical reaction in a carbon dioxide reduction device, a carbon dioxide reduction device using the same, and a method for reducing carbon dioxide using the same.

In order to achieve the above object, according to one aspect of the present invention, the present invention is a current collector in the form of a plate and used in a carbon dioxide reduction device, the current collector comprising a body portion, and a protrusion formed integrally with the body portion provides

In another aspect, the present invention comprises a first chamber comprising a gas inlet and a gas outlet, a second chamber comprising a first current collector, a reducing electrode, a proton exchange membrane, a second current collector and an oxidizing electrode, wherein the second chamber comprises: At least one of the first current collector and the second current collector is the current collector, and provides a carbon dioxide reduction device.

In another aspect, the present invention provides a method for reducing carbon dioxide using the carbon dioxide reduction device.

Reaction stability of the carbon dioxide reduction reaction can be improved by using the current collector of the present invention.

In addition, using the current collector of the present invention, it is possible to convert the liquid product by the electrochemical reduction of formic acid and carbon dioxide by carbon dioxide reduction with higher efficiency.

The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical spirit of the present invention together with the above-described content of the present invention, so the present invention is limited to the matters described in those drawings It should not be construed as being limited.
1 illustrates a front view of a current collector 100 according to an embodiment.
2 shows a perspective view (a), a front view (b), and a side view (c) of the first chamber according to an embodiment.
3 illustrates a perspective view (a), a front view (b), and a side view (c) of a third chamber according to an embodiment.
4 is a perspective view of a fourth chamber according to an embodiment.
5 shows an SEM image of a gas diffusion electrode manufactured according to an embodiment.
6 shows a schematic diagram of a carbon dioxide reduction device according to an embodiment.
7 is a graph showing the efficiency of the carbon dioxide reduction reaction according to an embodiment. Specifically, a graph evaluating the conversion efficiency by varying the electrolyte concentration in the catholyte is shown.
8 is a graph showing the evaluation results of the cyclic voltammetry according to each voltage using the carbon dioxide reduction device according to an embodiment.
9 shows SEM images before (a) and after (b) performing a durability test for 72 hours at _{-0.76 V RHE} of a gas diffusion electrode according to an embodiment. (c) shows the XRD spectrum obtained before and after the durability test.

Hereinafter, the present invention will be described in detail with reference to the drawings.

The current collector of the present invention is a current collector in the form of a plate and used in a carbon dioxide reduction device, and includes a body portion and a protrusion formed integrally with the body portion.

Specifically, the current collector has a convex shape, and may have a body portion and at least one protrusion formed integrally with the body portion.

In one embodiment, the current collector, an opening for accommodating the electrode layer for carbon dioxide reduction reaction is formed in the interior of the flat surface.

In one embodiment, the body portion may have a rectangular shape, and the opening may have a rectangular shape corresponding to the body portion. For example, the body portion may have a rectangular shape as a shape corresponding to the shape of the electrode layer used in the carbon dioxide reduction device, and the opening may also have a rectangular shape. In addition, when a rectangular electrode is used, it is preferable that the size of the opening has at least a portion of a contact area in which the current collector and the electrode are in contact. For example, the opening may have a shape in which the electrode is reduced by 5 to 25%.

In addition, the current collector may include at least one fastening portion for fixing to the carbon dioxide reduction device, for example, at least one hole to which a bolt is coupled. The number of the fastening parts may be provided so that each component in the device does not leak, for example, provided at each corner of the current collector, the rectangular current collector may have four fastening parts. The size of the fastening part may be adjusted according to, for example, the size of the bolt.

In one embodiment, the body portion of the current collector to be fastened in each chamber in the carbon dioxide reduction device, so as not to contact the air surface outside the chamber, each corner may have a shape having an indentation in the direction of the center.

The current collector may be one used for at least one of the reduction electrode, the oxidation electrode, and the reference electrode of the carbon dioxide reduction device, and the material of the current collector is provided by determining the material so that the reaction is not performed in the current collector according to the electrode used can do. For example, the current collector may include at least one selected from the group consisting of copper, nickel, aluminum, platinum, palladium, silver, gold, and alloys thereof.

In one embodiment, the current collector may be made of a material plated with gold on a copper surface.

When the current collector is used, the stability of the carbon dioxide reduction reaction can be excellently improved compared to a carbon dioxide reduction device using, for example, a copper tape such as a conventional conductive tape or a conductive foil as a current collector.

In one embodiment, referring to FIG. 1 , the current collector 100 includes a body portion 101 and a protrusion portion 102 integral with the body portion, and an opening 103 having a shape corresponding to the rectangular body portion. ) is included. In addition, at least one fastening portion 104 may be included at each corner of the body portion.

The present invention provides a carbon dioxide reduction device using the current collector.

The carbon dioxide reduction device, a first chamber including a gas inlet and a gas outlet; a second chamber including a first current collector, a reduction electrode, a proton exchange membrane, a second current collector, and an oxidizing electrode, wherein at least one of the first current collector and the second current collector uses the current collector described above do.

2 shows a perspective view (a), a front view (b), and a side view (c) of the first chamber according to an embodiment.

The first chamber 200 includes a gas inlet 201 for supplying gaseous carbon dioxide into the device so that carbon dioxide can participate in a gaseous reduction reaction, and a gaseous reaction product, unreacted carbon dioxide or their and a gas outlet 202 for discharging the mixture. In addition, a gas flow path 203 may be included to allow gas such as carbon dioxide to flow.

In one embodiment, the first chamber may include two or more gas inlets. For example, the first chamber may include a first inlet for introducing carbon dioxide and a second inlet for introducing inert gas.

In one embodiment, the first chamber may include at least one fastening portion 204 for the purpose of coupling and close contact with the carbon dioxide reduction device.

The second chamber includes a first current collector, a reduction electrode, a proton exchange membrane, a second current collector and an oxidation electrode. The proton exchange membrane is provided between the reduction electrode and the oxidation electrode so that the ions in the electrolyte of the catholyte and/or the anolyte in which each electrode is immersed can communicate to maintain the pH of the electrolyte.

In one embodiment, the proton exchange membrane may use a Nafion membrane.

In addition, the second chamber is separated by a proton exchange membrane, and includes a reduction reaction unit in which a reduction reaction of carbon dioxide occurs, including a first current collector and a reduction electrode, and a second collector and an oxidation electrode, the relative reaction of the reduction reaction It may be separated into an oxidation reaction part where phosphorus water oxidation reaction occurs.

In one embodiment, the reduction reaction unit may be provided as a third chamber and the oxidation reaction unit as a fourth chamber, and a proton exchange membrane may be disposed between the third chamber and the fourth chamber.

3 shows a perspective view (a) and a front view (b) of the third chamber according to an embodiment.

4 shows a perspective view (a) and a front view (b) of the fourth chamber according to an embodiment.

In one embodiment, the proton exchange membrane is in contact with the opening of the upper surface of the third chamber 300, the gas diffusion electrode (GDE) is in contact with the opening of the lower surface, and after the proton exchange membrane is fastened, the opposite with respect to the proton exchange membrane The fourth chamber 400 may be fastened to the surface.

When the device is driven, the electrolyte (cathode solution) is supplied to the third chamber 300 through the electrolyte inlet 302 , and the depleted electrolyte (cathode solution) may be discharged through the electrolyte outlet 303 . In addition, the gaseous product generated through the reduction reaction may be discharged to the outside of the apparatus through the gaseous product outlet 304 and then collected.

In one embodiment, when the carbon dioxide reduction device is driven by a three-electrode system including a reference electrode, the third chamber 300 may include a reference electrode coupling part 301 so that the reference electrode can be disposed close to the reduction electrode. have.

In one embodiment, in the fourth chamber 400 , the proton exchange membrane may be in contact with the opening on the surface in contact with the third chamber 300 , and the counter electrode (oxidation electrode) may be in contact with the opposite surface. At this time, the gas product generated by the reaction performed at the oxidizing electrode, for example, oxygen gas generated by the electrolysis of water is discharged to the outside of the device through the gas product outlet 401 of the fourth chamber 400 and can be collected thereafter. have.

The second chamber includes a reduction electrode and a first current collector at one end (or the third chamber), and the reduction electrode may be manufactured in a plate shape such as a rectangle or a circle, and using a gasket of a corresponding form The reduction electrode and/or the first current collector may be fixed to one end of the second chamber. The gasket is not particularly limited as long as it is a material of a flexible material having no electrical conductivity, and may be made of, for example, a material such as silicon (Si).

In one aspect, when the above-described current collector is used as the first current collector, the gasket may be prepared to correspond to the shape of the body portion of the current collector.

Specifically, the reduction electrode may use a gas diffusion electrode, wherein the gas diffusion electrode includes a conductive substrate and a catalyst layer formed on the conductive substrate.

In one aspect, the gas diffusion electrode may be a gas diffusion electrode known to be used in a carbon dioxide reduction device.

In another aspect, the gas diffusion electrode may include a conductive substrate, a metal thin film layer coated on the conductive substrate, and tin catalyst fine particles formed on the metal thin film layer. In this case, the metal thin film layer and the tin catalyst fine particles may exhibit catalytic activity on the conductive substrate.

The conductive substrate may act as a medium in which the gas diffuses, and may represent a porous material or a network. The conductive material may be, for example, a metal-based or carbon-based material, and more specifically, a metal mesh, metal foam, metal cloth, carbon cloth, carbon paper, carbon wire, or other porous conductive material. However, it is not limited thereto.

A rear surface of the conductive substrate with respect to the metal thin film layer may further include a gas diffusion layer. The gas diffusion layer may include, for example, a fluororesin coating, and the fluororesin coating may include, for example, polyethylene tetrafluoride (PTFE), another fluorinated binder, or a mixture thereof.

The catalyst layer or the metal thin film layer is not particularly limited as long as it is a metal known to exhibit catalytic activity in the reduction reaction of carbon dioxide, for example, a group consisting of tin, palladium, mercury, gold, silver, nickel, copper, cadmium, lead and indium. It may include at least one metal selected from In one aspect, the catalyst layer or the metal thin film layer may include tin.

In addition, the metal thin film layer may improve the electrochemical performance of the gas diffusion electrode and provide a smooth surface on the conductive substrate to stably form a catalyst on the metal thin film layer, but the present invention is not limited thereto .

The metal thin film layer may have a thickness of 5 to 500 nm, for example, 10 to 400 nm, 50 to 300 nm, 50 to 200 nm, or 50 to 150 nm.

The metamorphic tin catalyst fine particles formed on the metal thin film layer may have, for example, a cherry blossom shape. Hereinafter, in the present specification, SnCB denotes a gas diffusion electrode including the changeable tin catalyst fine particles. can

The metamorphic tin catalyst fine particles may have a shape having a flat surface and a thickness surface.

The dimensions of the flat surface and the thickness surface may be expressed as an average numerical value of 100 to 500 particles from the SEM image.

Specifically, the average thickness of the tin catalyst fine particles may be 10 to 1,000 nm, for example, 100 to 800 nm, 300 to 800 nm, or 300 to 600 nm.

In addition, the flat surface of the transformation tin catalyst fine particles may have an average long diameter of 0.1 to 100 nm, for example, 0.5 to 50 μm, 1 to 30 μm, or 3 to 10 μm. In addition, the flat surface of the transformation tin catalyst fine particles may have an average minor diameter of 50 to 10,000 nm, for example, 100 to 8,000 nm, 500 to 5,000 nm, or 1,000 to 5,000 nm. The major axis may be measured based on the longest length of the flat part, and it may be preferable to measure the major axis and the minor axis to be perpendicular to each other.

The above-described chemical transformation tin catalyst fine particles have an increased electrochemically activated specific surface area, and thus electrical conductivity is formed, which causes electrochemical activity of the catalyst at high current density, thereby exhibiting high catalytic activity on the gas diffusion electrode. can

More specifically, the gas diffusion electrode has a problem with forming a catalyst using a binder, such as a decrease in catalytic activity due to a decrease in the catalytic active area, a problem of lowering the conversion rate of carbon dioxide into formic acid, a problem of lowering the reaction stability, etc. In order to solve the problem, the catalyst may be formed without the use of a binder.

For example, the gas diffusion electrode may be manufactured according to a manufacturing method comprising the steps of forming a metal thin film layer on a conductive substrate and forming tin catalyst microparticles by electrodeposition on the metal thin film layer.

In addition, by forming the metal thin film layer by electron beam irradiation treatment, the conductive substrate may have a catalyst layer without the use of a binder.

In addition, the 'binder' refers to a binder used to form a catalyst layer on a conventional gas diffusion electrode, for example, but not limited thereto, and may be an ionomer containing fluorine. In one aspect, the gas diffusion electrode may have a catalyst layer formed without using a resin that is commercially available as Nafion®.

Next, the gas diffusion electrode may be manufactured by forming a metal thin film layer on the conductive substrate and then forming tin catalyst particles by electro-deposition.

The plating solution for the electrodeposition may include at least one of tin oxide and a salt thereof, for example, may include Na ₂ SnO ₃ ·3H ₂ O. The plating solution may further include NaOH.

In particular, the electrodeposition may be performed under basic conditions. In general, in the technique of electroplating tin, _{it may be carried out under acidic conditions to prevent the formation of hydroxide (Sn(OH) 2} ) of tin, but in the present invention, under basic conditions to prevent dissolution of the metal thin film layer may be performed.

For example, when the plating solution contains tin oxide, such as Na ₂ SnO ₃ , the plating solution is electroplating under basic conditions, such as 0.01 M to 0.5 NaOH, specifically 0.4 M NaOH, to electrodeposit tin catalyst fine particles. may be doing

The inventors of the present invention confirmed through an experiment that the temperature of the plating solution is important when considering the shape of the tin catalyst formed in the step of forming the tin catalyst fine particles by the electrodeposition. Specifically, when the temperature of the plating solution for electrodeposition is too low, a large amount of hydrogen generating reaction may be caused on the electrode rather than Sn electrodeposition, and when the temperature of the plating solution is too high, the formed catalyst is formed in a plane, so that the surface area of the catalyst is It was confirmed that there may be a problem that the catalytic activity is lowered. Accordingly, the temperature of the plating solution for the electrodeposition is not limited thereto, but may be, for example, a temperature of 0 to 55°C, specifically 10 to 50°C, 15 to 45°C, 20 to 40°C, 20 to 35°C. °C, 20-30 °C or 25 °C.

In addition, the gas diffusion electrode may be manufactured using a conductive substrate having a planar area ^{of 1 cm 2} or more, and thus a gas diffusion electrode in which a catalyst for carbon dioxide reduction reaction is formed on a planar area of ^{1 cm 2 or more.}

In one aspect, the gas diffusion electrode may be 1 cm ² to 10 cm ² , such as 1 cm ² to 10 cm ² _, 2 cm ² to 9 cm ² _, 3 cm ² to 8 cm ² _, 4 cm ² to 7 cm ² _, 4 cm ² to 6 cm ² .

The second chamber may include an oxide electrode at the other end (or the fourth chamber).

The oxide electrode may be at least one selected from the group consisting of nickel (Ni), iron (Fe), iridium (Ir), oxides thereof, and alloys thereof.

Furthermore, the second chamber may be to further include a reference electrode for measuring the electrode potential in the carbon dioxide reduction device. The reference electrode may be disposed close to the reduction electrode in order to cancel the generation of resistance, for example, may be disposed in the reduction reaction unit. The reference electrode is not limited thereto, but may be Ag/AgCl or the like.

At least one current collector in the first chamber, the second chamber, and the second chamber may be sealed and coupled by a fastening part that can connect while passing through them.

In another aspect, the present invention provides a method for reducing carbon dioxide using the carbon dioxide reduction device.

Specifically, the present invention provides a carbon dioxide reduction method using the above-described carbon dioxide reduction device.

First, carbon dioxide is supplied to the first chamber through the gas inlet. The supplied carbon dioxide flows through the gas flow path, and in this case, carbon dioxide may be reduced on the reduction electrode of the second chamber.

In the present invention, by using the current collector as described above as the current collector in contact with the reduction electrode, a stable current is supplied to improve the reaction stability of the reduction reaction, thereby exhibiting the effect of improving the yield of the reduction reaction.

In addition, by using the above-described gas diffusion electrode as the reduction electrode, for example, a gas diffusion electrode including a conductive substrate, a metal thin film layer, and a fire-transformation tin catalyst fine particles, it is possible to excellently improve the reduction yield of carbon dioxide. In addition, it can exhibit the effect of excellently improving the conversion yield of carbon dioxide into formic acid and formic acid salt.

When the gas diffusion electrode described above is used as the gas diffusion electrode, the present inventors have confirmed that the concentration of the buffer salt in the catholyte has an important effect on the conversion efficiency of carbon dioxide into formic acid and its salts.

More specifically, the concentration of the buffer salt, such as KHCO ₃ in the catholyte may be, for example, 0.05 M to 5 M, 0.1 M to 4 M, 0.1 M to 3 M, 0.1 to 2 M, or 0.5 to 1.5 M can be The concentration of the buffer salt in the catholyte is not limited thereto, but when the concentration of the buffer salt is within the above range, the conversion yield from carbon dioxide to formic acid may be excellently improved.

Hereinafter, the present invention will be described with reference to drawings, examples, and the like.

Example 1. Preparation of a current collector

In FIG. 1, a current collector was manufactured according to a drawing of a current collector according to an embodiment. As a material of the current collector, copper plated with gold was used.

Example 2. Preparation of carbon dioxide reduction device

[Production of reduction electrode]

(1) Preparation of carbon cloth with Sn metal thin film layer (Sn/CC)

Carbon cloth (CC, CeTech) was used as the gas permeable substrate. The back side of the substrate was coated with polytetrafluoroethylene (PTFE) under _{N 2} conditions to be _{0.3 mg PTFE} ·cm ^-2. PTFE ink was prepared by diluting a solution of PTFE (60%, Sigma Aldrich) in anhydrous ethyl alcohol (Sigma Aldrich) to 1%. An Sn thin film layer was formed on CC under ultra-high vacuum conditions using an E-beam evaporator (Daeki High-Tech). Sn shots (99.999 %, Alfa Aesar) were used as the Sn source. Sn was ^{deposited at a deposition rate of 0.7 Å·s −1} until it became a quartz crystal having a thickness of 100 nm. The bulk density and Z factor of the Sn thin film layer were 7.30 g·cm ⁻³ and 0.724, respectively.

(2) Formation of fire transformation Sn catalyst fine particles on Sn/CC (SnCB/Sn/CC)

Fire transformation Sn catalyst fine particles (SnCB) were electrodeposited on Sn/CC.

For the preparation of the working electrode for electrodeposition, the Sn/CC substrate was placed on a glass slide and then Cu tape was used for electrical contact. The other part was covered with an ^{epoxy adhesive (Loctite® EA 9460 TM} ) to expose only the Sn surface to the electrolyte. A potential difference was formed using a potential difference regulator (ZIVE BP2, WonATech) and a voltage device (WonATech). A Hg/HgO electrode (RE-61AP, ALS) filled with 1 M NaOH (Sigma-Aldrich) and a Sn wire (99.99 %, Nilaco) were used as reference and counter electrodes, respectively.

After fixing the three electrodes on a separately prepared cell, 1M Na ₂ SnO ₃ ·3H ₂ O (Sigma-Aldrich) and 0.4 M NaOH (Sigma-Aldrich) were mixed to prepare a plating solution, and -4.0 V for 80 minutes. A constant voltage of _{Hg/HgO was applied.}

Three samples were prepared using a plating solution at 25°C, and after electrodeposition was completed, the prepared electrode was rinsed with DI several times and sonicated to remove impurities in DI. After wiping the surface, it was dried in an oven at 50° C. and kept in a desiccator.

5 shows an SEM image of a gas-oxidized electrode prepared by electrodeposition at 25°C.

[Production of carbon dioxide reduction device]

A first chamber (FIG. 2), a third chamber (reduction reaction unit, FIG. 3), a proton exchange membrane, and a fourth chamber (oxidation reaction unit, FIG. 4) were prepared.

In this case, as the gas diffusion electrode, the gas diffusion electrode prepared by using the plating solution at 25° C. was used.

The current collector and the gas diffusion electrode prepared above are fixed to one end of the first chamber with a Si gasket, the third chamber, the proton exchange membrane, the fourth chamber, and the oxide electrode are fixed, and a cover plate is attached. fixed. Each of the above components was fixed using four long bolts.

6 shows a schematic diagram of the carbon dioxide reduction device.

Experimental Example 1. Evaluation of reduction efficiency of carbon dioxide using a carbon dioxide reduction device

Using the carbon dioxide reduction apparatus of Example 2, the reduction efficiency of carbon dioxide was evaluated in the following way.

_{At this time, KHCO 3} was used as the catholyte in the third chamber, and the conversion efficiency was evaluated by varying the concentration of the electrolyte to 0.1M, 0.5M, 1.0M, and 2.0M.

In addition, the flow rate of the electrolyte was maintained at 4 ml/min, and the carbon dioxide was maintained to flow at 50 sccm.

The results are shown in FIG. 7 . As can be seen in FIG. 7 , it was confirmed that carbon dioxide can be converted to formate with an efficiency of about 75% by using the carbon dioxide reduction device. In particular, when 1M electrolyte is used, the conversion rate of formate with high efficiency even at low voltage It was confirmed that it can be improved.

Experimental Example 2. Durability evaluation of carbon dioxide reduction device

The durability of the device according to the repeated experiment using the carbon dioxide reduction device of Example 2 was evaluated using a cyclic voltammetry, and the results are shown in FIG. 8 .

_{In addition, after carbon dioxide reduction was performed for 72 hours at a fixed voltage of -0.76 V RHE} using the carbon dioxide reduction device of Example 2, changes before and after the reaction of the gas diffusion electrode were observed and shown in FIG. 9 . For continuous experiments, 250 mL of CO ₂ -saturated 1M KHCO ₃ catholyte was circulated and the liquid product was stored in the catholyte.

Referring to the above experimental results, it was confirmed that when carbon dioxide is reduced using the current collector according to the present invention, stable operation of the reduction device is possible compared to the case of reducing carbon dioxide using a conventional tape-type current collector.

100: current collector 101: body portion
102: protrusion 103: opening
104: fastening unit 200: first chamber
201: gas inlet 202: gas outlet
203: gas flow path 204: fastening part
300: third chamber 301: reference electrode fastening part
302: electrolyte inlet 303: electrolyte outlet
304: gas product outlet 400: fourth chamber
401: gas product outlet

Claims (17)

As a current collector in the form of a plate and used in a carbon dioxide reduction device,
A current collector comprising a body and a protrusion integrally formed with the body.
The method according to claim 1,
The current collector which has an opening for accommodating the electrode layer for carbon dioxide reduction reaction in the interior of the flat surface.
3. The method according to claim 2,
The body portion has a rectangular shape, and the opening has a rectangular shape corresponding to the body portion, the current collector.
The method according to claim 1,
The current collector material includes at least one selected from the group consisting of copper, nickel, aluminum, platinum, palladium, silver, gold, and alloys thereof.
a first chamber comprising a gas inlet and a gas outlet;
a second chamber comprising a first current collector, a reducing electrode, a proton exchange membrane, a second current collector and an oxidizing electrode;
At least one of the first current collector and the second current collector is a current collector according to any one of claims 1 to 4, a carbon dioxide reduction device.
6. The method of claim 5,
The reduction electrode is a carbon dioxide reduction device that is a gas diffusion electrode comprising a conductive substrate and a catalyst layer formed on the conductive substrate.
6. The method of claim 5,
The reduction electrode is
conductive substrate,
A metal thin film layer coated on the conductive substrate, and
A carbon dioxide reduction device which is a gas diffusion electrode comprising fine particles of a tin catalyst formed on the metal thin film layer.
8. The method according to claim 6 or 7,
The catalyst layer or the metal thin film layer is a carbon dioxide reduction device comprising at least one metal selected from the group consisting of tin, palladium, mercury, gold, silver, nickel, copper, cadmium, lead and indium.
8. The method of claim 7,
The gas diffusion electrode is a carbon dioxide reduction device having a planar area ^{of 1 cm 2 or more.}
8. The method of claim 7,
The carbon dioxide reduction device of the fire transformation tin catalyst fine particles having an average thickness of 10 to 1,000 nm.
8. The method of claim 7,
The carbon dioxide reduction device of the planar surface of the transformation tin catalyst fine particles having an average major diameter of 0.1 to 100 μm and an average minor diameter of 50 to 10,000 nm.
8. The method according to claim 6 or 7,
The gas diffusion electrode,
A carbon dioxide reduction device in which a catalyst is formed on the conductive substrate without the use of a binder.
8. The method of claim 7,
The metal thin film layer is a carbon dioxide reduction device that is formed by electron beam irradiation treatment.
8. The method of claim 7,
The carbon dioxide reduction device of the fire transformation (flower shape) tin catalyst fine particles are formed by electrodeposition carried out at a temperature of 0 to 55 ℃.
6. The method of claim 5,
Carbon dioxide reduction device that further comprises a reference electrode.
Using the carbon dioxide reduction device according to claim 5, carbon dioxide reduction method.
17. The method of claim 16,
A method for reducing carbon dioxide using a catholyte having a buffer salt concentration of 0.05 M to 5 M.

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