KR20190125822A - Electrochemical CO2 conversion device including Anion exchange membrane-Cation exchange membrane and carbon dioxide conversion method using same - Google Patents

Abstract

The present invention relates to an electrochemical CO_2 conversion reactor having CEM-AEM and a driving method thereof. More specifically, a carbon dioxide converter with high CO_2 conversion efficiency by using a carbon dioxide conversion device includes a cathode, an anode facing the cathode, and an electrolyte membrane positioned between the cathode and the anode, wherein the electrolyte membrane includes an anion exchange membrane in contact with the cathode and a cation exchange membrane in contact with the anode, and the anion exchange membrane and the cation exchange membrane are in contact with each other to have a junction structure.

Description

Electrochemical CO2 conversion device including Anion exchange membrane-Cation exchange membrane and carbon dioxide conversion method using same}

The present invention relates to an electrochemical CO ₂ conversion apparatus including an anion exchange membrane and a cation exchange membrane and a carbon dioxide conversion method using the same, and more particularly, to a production of a carbon dioxide converter having a high CO ₂ conversion efficiency, including an anion exchange membrane.

Since the conclusion of the Paris Agreement, which laid down the framework for climate change response, countries around the world have made various transitions to GHG reduction and energy policy decisions.

Therefore, it is desirable to find and develop a method of reducing the amount of carbon dioxide emission, which is a greenhouse gas into the atmosphere.

The way in which carbon dioxide is electrochemically reduced is classified according to the ion exchange method. Among them, the reduction of electrochemical carbon dioxide using a cation exchange membrane causes water to decompose in the anode to generate oxygen, electrons, and hydrogen ions. In the cathode, carbon dioxide reacts with the electrons from the anode, causing a reduction reaction, which is converted into another substance.

The liquid form of the reduced product of carbon dioxide has the advantage of higher energy density and easier handling than the gaseous form. In particular, formic acid has a higher price than other liquid carbon dioxide reduction products, and has the advantage that it can be used in the synthesis of medicines and in the production of paper and pulp. Because of this, formic acid has received much attention compared to other materials that can be produced by reducing carbon dioxide.

In general, in the liquid phase reduction reaction in which carbon dioxide is saturated in a liquid electrolyte and supplied to a cathode, the Faraday efficiency (or current efficiency) is 80% or higher, compared to the gas phase reduction reaction, but the product is mixed with the liquid electrolyte. The concentration of the product is very low, at the level of several ppm. This requires very low product value and requires separate separation and concentration processes.

On the other hand, in the case of gas phase reduction reaction in which carbon dioxide is directly supplied to the cathode, Faraday efficiency is reported to be 10% of the highest performance. In addition, the concentration of the product in the gas phase reduction of carbon dioxide is also very low value as a product in the level of several to several tens of mmol / L (a few thousand ppm level). Accordingly, a separate separation and concentration process is required.

In addition, the conventional electrochemical conversion device for carbon dioxide has a problem that the carbon dioxide conversion rate is low by saturating the active state of the carbon dioxide is converted to excess hydrogen ions from the anode to the cathode.

Thus, there is a need for an electrochemical process that provides improved overall engineering and overall performance.

Korean Patent Publication KR 10-2015-0036093

The technical problem to be achieved by the present invention is to provide an electrochemical CO ₂ conversion device. More specifically, the present invention provides an effect of increasing the CO ₂ conversion efficiency by using an electrochemical CO ₂ conversion reactor including a cation exchange membrane and an anion exchange membrane and a driving method thereof.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned above may be clearly understood by those skilled in the art from the following description. There will be.

In order to achieve the above technical problem, an embodiment of the present invention provides a carbon dioxide conversion device includes a cathode, an anode facing the cathode and an electrolyte membrane positioned between the cathode and the anode, the electrolyte The membrane includes an anion exchange membrane in contact with the cathode and a cation exchange membrane in contact with the anode, wherein the anion exchange membrane and the cation exchange membrane are in contact with each other and have a junction structure.

In an embodiment of the present invention, the cathode is Sn, Sn alloy, Al, Au, Ag, C, Cd, Co, Cr, Cu, Cu alloy, Ga, Hg, In, Mo, Nb, Ni, NiCo ₂ O ₄ , Ni alloy, Ni-Fe alloy, Pb, Rh, Ti, V, W, Zn, elgiloy, nichrome, austenitic steel, duplex steel, ferrite steel, martensite steel, stainless steel or their It may be characterized by including one or more selected from the group consisting of a mixture.

In addition, the anode includes one or more selected from the group consisting of platinum, gold, silver, palladium, iridium, rhodium, ruthenium, osmium, tin, iron, cobalt, nickel, molybdenum, tungsten, vanadium, or mixtures thereof. It can be characterized.

In addition, the anion exchange membrane may be characterized in that to reduce the amount of hydrogen ions generated in the anode to pass to the cathode.

In addition, the anion exchange membrane may be characterized in that it comprises a hydrocarbon system.

In addition, the cation exchange membrane is polyvinylidene fluoride (PVDF), polyamide, polyester, polysulfone, polyethylene, polypropylene, styrene, acrylic acid, methacrylic acid, glycidyl acrylate, glycidyl methacrylate, It may be characterized in that it comprises at least one member selected from the group consisting of polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, ethylene glycol dimethacrylate and cellulose.

In order to achieve the above technical problem, another embodiment of the present invention provides a carbon dioxide electrochemical reduction method. The electrochemical reduction method includes injecting carbon dioxide into a cathode through a first inlet, injecting water or an electrolyte into an anode into a second inlet, and applying voltage to the anode and the cathode to apply water to the anode or the cathode. Decomposing an electrolyte solution and reducing the injected carbon dioxide at the cathode, between the anode and the cathode.

 An electrolyte membrane is positioned, wherein the electrolyte membrane includes an anion exchange membrane in contact with the cathode and a cation exchange membrane in contact with the anode, and the anion exchange membrane and the cation exchange membrane are in contact with each other and have a junction structure. The exchange membrane is characterized in that the amount of hydrogen ions generated while decomposing the water or the electrolyte at the anode is reduced to the cathode.

In addition, the electrolyte solution is KHCO ₃ , K ₂ CO ₃ , KOH, KCl, KClO ₄ , K ₂ SiO ₃ , Na ₂ SO ₄ , NaNO ₃ , NaCl, NaF, NaClO ₄ , CaCl ₂ , guanidinium cation, H ⁺ Cations, alkali metal cations, ammonium cations, alkylammonium cations, halide ions, alkyl amines, borates, carbonates, guanidinium derivatives, nitrites, nitrates, phosphates, polyphosphates, perchlorates, silicates, sulfates, tetraalkyl ammonium salts, Or an aqueous solution containing a mixture thereof.

In addition, the temperature of the step of reducing the carbon dioxide may be characterized in that 10 ℃ to 100 ℃.

According to an embodiment of the present invention, it is possible to provide the effect of converting carbon dioxide to a valuable hydrocarbon-based compound.

In addition, the present invention can provide an effect of increasing the carbon dioxide conversion efficiency by minimizing the hydrogen reaction.

In addition, the present invention can convert carbon dioxide stably without being restricted by the place.

The effects of the present invention are not limited to the above-described effects, but should be understood to include all the effects deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a schematic diagram showing the structure of the carbon dioxide conversion device of the present invention.
2 is a flow chart showing a carbon dioxide electrochemical reduction method of the present invention.
3 to 4 are graphs of current density measurement results over time.
5 to 6 are graphs showing the results of the conversion product analysis.

Hereinafter, with reference to the accompanying drawings will be described the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, coupled)" with another part, it is not only "directly connected" but also "indirectly connected" with another member in between. "Includes the case. In addition, when a part is said to "include" a certain component, this means that it may further include other components, without excluding the other components unless otherwise stated.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. As used herein, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described on the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram showing the structure of the carbon dioxide conversion device of the present invention.

1, a cathode, an anode facing the cathode, and an electrolyte membrane positioned between the cathode and the anode, wherein the electrolyte membrane includes an anion exchange membrane in contact with the cathode and a cation exchange membrane in contact with the anode, wherein the anion The exchange membrane and the cation exchange membrane may be in contact with each other and have a junction structure.

For example, the cathode is Sn, Sn alloy, Al, Au, Ag, C, Cd, Co, Cr, Cu, Cu alloy, Ga, Hg, In, Mo, Nb, Ni, NiCo ₂ O ₄ , Ni alloy , Ni-Fe alloy, Pb, Rh, Ti, V, W, Zn, elgiloy, nichrome, austenitic steel, duplex steel, ferrite steel, martensite steel, stainless steel or mixtures thereof It may be characterized by including one or more selected from.

When carbon dioxide is supplied to the cathode voltage is applied to the carbon dioxide conversion _{device, 3CO 2 + H 2 + 2e} - → CO + 2HCO 3 - may be carbon dioxide is reduced as shown in the following scheme.

The anode may be disposed to face the cathode.

For example, the anode includes at least one selected from the group consisting of platinum, gold, silver, palladium, iridium, rhodium, ruthenium, osmium, tin, iron, cobalt, nickel, molybdenum, tungsten, vanadium or mixtures thereof. It can be characterized by.

The anode may be characterized in that it comprises a metal or transition metal.

When the water or electrolyte solution to the anode supply and a voltage is applied to the carbon dioxide conversion _{device, 2H 2 O → O 2 +} 4H + + 4e - has the same principle as the reaction formula can be a hydrogen ion generated at the anode.

The electrolyte membrane may be located between the cathode and the anode.

In addition, the electrolyte membrane may include an anion exchange membrane in contact with the cathode and a cation exchange membrane in contact with the anode, and the anion exchange membrane and the cation exchange membrane may have a junction structure in contact.

In the junction H ^{+ +} HCO ₃ ^-, water can be generated in a reaction scheme such as _{^{→ H 2 O - → CO 2}} + H 2 O, H + + OH.

Therefore, water may be generated during the carbon dioxide conversion process in the electrolyte membrane, and the humidification process is not necessary when the carbon dioxide is injected into the cathode due to the generated water. Can provide.

In addition, the anion exchange membrane may be characterized in that to reduce the amount of hydrogen ions generated in the anode to pass to the cathode.

The conventional carbon dioxide conversion device has a problem of having a low carbon dioxide conversion efficiency because an excess of hydrogen ions (H ⁺ ) generated from the anode is passed to the cathode to saturate the active site of the catalyst to convert carbon dioxide.

The anion exchange membrane according to an embodiment of the present invention may serve as a buffer layer that can control the concentration of hydrogen ions by reducing the amount of hydrogen ions passing from the hydrogen ions generated at the anode to the cathode.

Accordingly, the anion exchange membrane of the present invention selectively controls excess hydrogen ions (H ⁺ ) from the anode to the cathode to prevent hydrogen saturation at the active site, and increases the selectivity of the electrochemical carbon dioxide conversion to the conventional problem Therefore, it can provide an effect of increasing the carbon dioxide conversion efficiency.

For example, the anion exchange membrane may be characterized in that it comprises a hydrocarbon system.

For the anion exchange membranes, due to the accumulation of hydrogen ions (H ⁺⁾ of the cation exchange membrane surface of the membrane electrode assembly to prevent the cathode carbon dioxide conversion performance is inhibited: is inserted into the (MEA Membrane electrode assembly), OH ^-, An anion such as HCO ₃ ⁻ , CO ₃ ^{2 −} may refer to a separate phase that can permeate.

In addition, the anion exchange membrane including the hydrocarbon-based may be a porous separator comprising a carbonate of the liquid electrolyte.

For example, the hydrocarbon system may include quaternary ammonium base, pyridinium base, imadazolium base, tertiary amino group or phosphonium group.

Anion exchange resin is commercially available, for example, Tokuyama Co. Ltd. Ltd. (A201), the trade name (Fumasep) of FuMA-TechGmbH, the trade name (Aciplex) of Asahi Chemical Industry Co., etc. can also be obtained.

For example, the cation exchange membrane is polyvinylidene fluoride (PVDF), polyamide, polyester, polysulfone, polyethylene, polypropylene, styrene, acrylic acid, methacrylic acid, glycidyl acrylate, glycidyl methacryl It may be characterized in that it comprises one or more selected from the group consisting of latex, polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, ethylene glycol dimethacrylate and cellulose.

In the case of the cation exchange membrane, it acts as a barrier membrane to prevent the reduction material or intermediate produced at the cathode to move to the anode by oxidation, inhibits the permeation of the anion and is permeable to cations such as hydrogen ions (H +) It may be a separate phase.

 In the present invention, the cation exchange membrane can be used without limitation that the cation is known to be conductive.

Specifically, a porous film, a nonwoven fabric, a woven fabric, paper, a nonwoven paper, an inorganic film, etc. can be provided. The material of these cation exchange membranes is not particularly limited, and thermoplastic resins, thermosetting resins, inorganic substances, and mixtures thereof can be used.

In addition, among the cation exchange membranes, it may be preferable to use a hydrogen fluoride membrane or a hydrocarbon membrane from the viewpoint of excellent mechanical strength, chemical stability and chemical resistance, and good affinity with the anion exchange resin.

 A cation exchange membrane can also be obtained as a commercial item, for example, the brand name [Nafion] from Dupont, the product name (Fumapem) of FuMA-TechGmbH, etc.

Therefore, the carbon dioxide conversion device characterized by the structure of the present invention is capable of converting carbon dioxide stably without being restricted by the effect of converting carbon dioxide to a valuable hydrocarbon-based compound, minimizing hydrogen reaction, and increasing the carbon dioxide conversion efficiency. Can provide an effect.

2 is a flow chart showing a carbon dioxide electrochemical reduction method of the present invention.

Referring to FIG. 2, injecting carbon dioxide into a cathode through a first inlet (S100), injecting water or an electrolyte into an anode in a second inlet (S200), and applying a voltage to the anode and the cathode to the anode. Decomposing the injected water or the electrolyte in the step, and reducing the injected carbon dioxide in the cathode (S300), the electrolyte membrane is located between the anode and the cathode, the electrolyte membrane is an anion exchange membrane in contact with the cathode And a cation exchange membrane in contact with the anode, wherein the anion exchange membrane and the cation exchange membrane are in contact with each other and have a junction structure, wherein the anion exchange membrane of the electrolyte membrane is generated while decomposing the water or the electrolyte at the anode. To reduce the amount of hydrogen ions passed to the cathode. Can.

First, carbon dioxide is injected into the cathode through the first inlet (S100).

According to an embodiment of the present invention, the injecting the carbon dioxide may not require a process of humidifying the carbon dioxide separately.

In the process of converting carbon dioxide of the present invention, a chemical reaction in which water is generated does not require a process of humidifying carbon dioxide, thereby providing an effect of shortening the process.

Next, water or electrolyte is injected into the anode at the second inlet (S200).

For example, the electrolyte is KHCO ₃ , K ₂ CO ₃ , KOH, KCl, KClO ₄ , K ₂ SiO ₃ , Na ₂ SO ₄ , NaNO ₃ , NaCl, NaF, NaClO ₄ , CaCl ₂ , guanidinium cation, H ⁺ cation, alkali metal cation, ammonium cation, alkylammonium cation, halide ion, alkyl amine, borate, carbonate, guanidinium derivative, nitrite, nitrate, phosphate, polyphosphate, perchlorate, silicate, sulfate, tetraalkyl It may be characterized in that it comprises an aqueous solution containing an ammonium salt, or a mixture thereof.

Subsequently, voltage is applied to the anode and the cathode to decompose the injected water or electrolyte at the anode, and the injected carbon dioxide is reduced at the cathode (S300).

For example, a chemical reaction scheme for generating hydrogen ions at the anode may be the following [Scheme 1].

Scheme 1

_{2H 2 O → O 2 + 4H} + + 4e -

In other words, the anode reactant in the present invention is a liquid phase. In the anode region, hydrogen ions can be formed only by supplying water, and hydrogen ions can be formed by supplying an electrolyte solution, specifically, an aqueous solution containing an electrolyte.

For example, a chemical reaction scheme for reducing carbon dioxide at the cathode may be the following [Scheme 2].

Scheme 2

^{_{3CO 2 + H 2 + 2e -}} → CO + 2HCO 3 -

In other words, the reactant in the cathode region is carbon dioxide. The reactant carbon dioxide is delivered to the cathode surface.

In addition, an electrolyte membrane is positioned between the anode and the cathode, wherein the electrolyte membrane includes an anion exchange membrane in contact with the cathode and a cation exchange membrane in contact with the anode, and the anion exchange membrane and the cation exchange membrane are in contact with a junction structure. Characterized in that,

The anion exchange membrane of the electrolyte membrane may reduce the amount of hydrogen ions generated while decomposing the water or the electrolyte in the anode to the cathode.

The anion exchange membrane may be characterized in that to reduce the amount of hydrogen ions passing from the hydrogen ions generated at the anode to the cathode.

In the conventional carbon dioxide conversion device, a hydrogen evolution reaction (HER) occurs on the surface of the cathode, when excess hydrogen ions are saturated, hydrogen is generated as a bond between hydrogen ions, thereby promoting HER, and a competitive reaction is carbon dioxide conversion. The reaction is suppressed.

Therefore, in the conventional case of using a cation exchange membrane alone as an electrolyte membrane, in the case of a cation exchange membrane, due to the property of selectively permeating cations including hydrogen ions, the excess hydrogen ions generated at the anode are transferred to the cathode and the carbon dioxide conversion rate is lowered. A problem has occurred.

The anion exchange membrane according to an embodiment of the present invention may serve as a buffer layer that can control the concentration of hydrogen ions by reducing the amount of hydrogen ions generated from the anode to the cathode.

Accordingly, the anion exchange membrane of the present invention selectively controls excess hydrogen ions (H ⁺ ) from the anode to the cathode to prevent hydrogen saturation at the active site, and increases the selectivity of the electrochemical carbon dioxide conversion to the conventional problem Therefore, it can provide an effect of increasing the carbon dioxide conversion efficiency.

For example, the chemical reaction scheme occurring at the junction may be the following [Scheme 3] and [Scheme 4].

Scheme 3

_{^{H + + HCO 3 - → CO}} 2 + H 2 O

Scheme 4

_{^{H + + OH - → H 2}} O

Due to the water generated at the anode during the carbon dioxide conversion process, it is provided to the ion exchange membrane so that the wet state can be maintained when the carbon dioxide is injected, so that a humidification process may not be required, and the carbon dioxide generated in the electrolyte membrane together with the carbon dioxide which is a reactant in the cathode region. Moisture (H ₂ O) is supplied to the electrolyte membrane.

Therefore, since it is possible to maintain the wet state, when injecting carbon dioxide, a humidifying process is not required, and thus, the process may be shortened.

In addition, the electrolyte membrane may include an anion exchange membrane in contact with the cathode and a cation exchange membrane in contact with the anode.

Since the anion exchange membrane selectively passes anions, the hydrogen ions cannot pass through the anion exchange membrane.

Therefore, less hydrogen ions are introduced to the cathode and hydrogen ions can be reduced by chemical reaction of the electrolyte membrane.

Since hydrogen ions are generated low, it is possible to prevent hydrogen ions from saturating at the active site of the catalyst and provide an effect of having high carbon dioxide conversion efficiency.

Therefore, according to the embodiment of the present invention, carbon dioxide may be reduced to provide a carbon dioxide reduction product.

For example, carbon dioxide reduction products include carbon monoxide, methane, ethane, ethylene, formic acid, formaldehyde, formate, acetaldehyde, acetate, acetic acid, acetone, 1-butanol, 2-butanol, 2-butanone, ethanol, isopropanol , Lactate, lactic acid, methanol, 1-propanal, 1-propanol, propionic acid or mixtures thereof.

The temperature of the step of reducing the reduced product of carbon dioxide may be characterized in that 10 ℃ to 100 ℃.

In addition, when the temperature of the reducing step is less than 10 ℃ water freezes to inhibit the movement of ions, volume expansion may damage the contact of the membrane electrode assembly (MEA: Membrane electrode assembly) may be reduced durability and performance. . Since the polymer glass transition temperature as the base material of the cation exchange membrane and the anion exchange membrane is 100 ° C., when the temperature exceeds 100 ° C., the durability and performance of the cation exchange membrane and the anion exchange membrane may decrease.

In addition, the cathode and anode relative humidity of the step of reducing the carbon dioxide (S300) is not particularly limited.

In the case of the carbon dioxide conversion reaction, hydrogen ions and anions react at the junction to generate water.

Considering the electrochemical reaction of the anode, which decomposes these water molecules to generate hydrogen ions, electrons, and oxygen, excess water is supplied to the anode and some of the water supplied to the anode can be used to keep the ion exchange membrane wet. have.

Thus, the water can be supplied not only from the anode but also from the ion exchange membrane.

Therefore, in the case of the carbon dioxide converter of the present invention, there is an effect that the relative humidity of the gas supplied to the cathode and the anode is not limited.

However, relative humidity of approximately 0% RH to 95% RH can be maintained at the operating temperature of the switching device.

More preferably, since the relative humidity uses an exchange membrane having ion conductivity, it may be desirable to maintain the relative humidity of the gas supplied to the cathode and the anode from 80% RH to 100% RH in the case of a fuel cell system and a cation exchange membrane electrolytic system. Can be.

For example, when the relative humidity of the gas to be supplied is less than 80% RH, the ion exchange membrane may be dried, resulting in high electrical resistance and a decrease in battery output.

In addition, the operation of the carbon dioxide conversion device may be characterized by including a constant current operation, constant voltage operation, load fluctuation operation.

In the constant current operation, a voltage of 1.5 V to 4.5 V may be applied to the anode and the cathode.

It is possible to apply a voltage of 3V or more to achieve a high current density, but when the voltage exceeds 4.5V, the hydrogen evolution reaction (HER) may increase rapidly at a high voltage.

Therefore, it is preferable to apply a voltage of 1.5V to 4.5V.

Production Example

1) Carbon dioxide was supplied to the cathode 200 through the first inlet 100 at a rate of 1 ml / min to 1000 ml / min per 1 cm ² of electrode area.

2) Water was supplied to the anode 400 through the second injection 500.

3) The relative humidity of the cathode and the anode was prepared from 80% RH to 100% RH, the temperature of 25 ℃ to 75 ℃.

4) A 3V voltage was applied to the anode and the cathode.

5) A potential difference was formed at the cathode and the anode and a current was flowed to generate a carbon dioxide conversion reaction.

Experimental Example

Using a carbon dioxide conversion device prepared according to the preparation example, applied voltage: 3.2 V (constant voltage operation), reaction temperature: 298 K, reaction pressure: 1 atm, electrolyte membrane: AEM-CEM membrane (CEM: Nafion 115, AEM: FumasepFAA-3-50), anode catalyst: Pt / C (TEC10E50E), cathode catalyst: 100 nm thick Aucatalyst layer, electrode area: 9 cm ² , anode reactant: 0.5 M KHCO ₃ aqueous solution 30 ml / min, cathode reactant: CO _The carbon dioxide conversion performance was tested in ₂ gas 20 ml / min conditions.

Comparative example

Using a carbon dioxide conversion device including a conventional MEA (Membrane Electrode Assembly), applied voltage: 3.2 V (constant voltage operation), reaction temperature: 298 K, reaction pressure: 1 atm, electrolyte membrane: CEM membrane (Nafion 115), anode Catalyst: Pt / C (TEC10E50E), Cathode catalyst: 100 nm thick Aucatalyst layer, Electrode area: 9 cm ² , Anode reactant: 0.5 M KHCO ₃ aqueous solution 30 ml / min, Cathode reactant: CO ₂ gas 20 ml / min Carbon dioxide conversion performance was tested.

3 to 4 are graphs of current density measurement results over time.

Referring to Figures 3 to 4, Figure 3 is a graph showing the experimental example, Figure 4 is a graph showing the comparative example.

Comparing FIG. 3 and FIG. 4, it is confirmed that the current density is shown as 8 mA / cm ² in FIG. 3, which is a 5 mA / cm ² TL experimental example graph in FIG. 4, which is a comparative example graph.

Therefore, the carbon dioxide conversion device having the structure of the present invention can confirm that more than about 60% of the current flows through Figure 3, it can be confirmed that as the current flows further increase the carbon dioxide conversion efficiency.

5 to 6 are graphs showing the results of the conversion product analysis.

5 to 6, Figure 5 is a graph showing the experimental example, Figure 6 is a graph showing the comparative example.

Comparing FIG. 5 and FIG. 6, it is confirmed that the comparative example has 23% hydrogen generation reaction current efficiency and the experimental example has 8% hydrogen generation reaction current efficiency.

5 having the structure of the present invention, due to the structure of the present invention, the control of hydrogen ions and 40% less than the hydrogen generation reaction standard of FIG. 6 using the conventional carbon dioxide conversion device, the carbon dioxide conversion device of the present invention is a hydrogen ion It can be seen that the control sufficiently.

CO ₂ conversion reaction to CO (Carbon monoxide) it can be seen that the experimental example graph of 85% in Figure 5 and the comparative example graph of 60% in FIG.

FIG. 5 confirms that the CO ₂ conversion efficiency increases by about 40% as side reactions are suppressed compared to FIG. 6.

Therefore, it can be seen that the carbon dioxide conversion device including the structure of the present invention may affect the chemical carbon dioxide conversion reaction through FIG.

In addition, it can be seen that the structure of the carbon dioxide conversion device of the present invention solves the problem of hydrogen saturation at the cathode surface, which was a problem of the conventional electrochemical reactor.

According to an embodiment of the present invention, it is possible to provide the effect of converting carbon dioxide to a valuable hydrocarbon-based compound.

In addition, the present invention can provide an effect of increasing the carbon dioxide conversion efficiency by minimizing the hydrogen reaction.

In addition, the present invention can convert carbon dioxide stably without being restricted by the place.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is represented by the following claims, and it should be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalents are included in the scope of the present invention.

100: first inlet
200: cathode
300: electrolyte membrane
310 anion exchange membrane
320: cation exchange membrane
400: anode
500: second inlet

Claims (9)

Cathode;
An anode facing the cathode; And
An electrolyte membrane positioned between the cathode and the anode,
The electrolyte membrane includes an anion exchange membrane in contact with the cathode and a cation exchange membrane in contact with the anode,
And the anion exchange membrane and the cation exchange membrane are in contact with each other and have a junction structure. The method of claim 1,
The cathode is Sn, Sn alloy, Al, Au, Ag, C, Cd, Co, Cr, Cu, Cu alloy, Ga, Hg, In, Mo, Nb, Ni, NiCo ₂ O ₄ , Ni alloy, Ni-Fe One selected from the group consisting of alloys, Pb, Rh, Ti, V, W, Zn, elgiloy, nichrome, austenitic steel, duplex steel, ferrite steel, martensite steel, stainless steel, or mixtures thereof A carbon dioxide conversion device comprising the above. The method of claim 1,
The anode is characterized in that it comprises one or more selected from the group consisting of platinum, gold, silver, palladium, iridium, rhodium, ruthenium, osmium, tin, iron, cobalt, nickel, molybdenum, tungsten, vanadium or a mixture thereof. CO2 conversion device. The method of claim 1,
The anion exchange membrane is a carbon dioxide conversion device, characterized in that for reducing the amount of hydrogen ions generated at the anode to pass to the cathode. According to claim 1,
The anion exchange membrane carbon dioxide conversion device, characterized in that it comprises a hydrocarbon system. The method of claim 1,
The cation exchange membrane is polyvinylidene fluoride (PVDF), polyamide, polyester, polysulfone, polyethylene, polypropylene, styrene, acrylic acid, methacrylic acid, glycidyl acrylate, glycidyl methacrylate, polyethylene glycol A carbon dioxide conversion device comprising at least one selected from the group consisting of diacrylate, 1,3-butylene glycol diacrylate, ethylene glycol dimethacrylate and cellulose. Injecting carbon dioxide into the cathode through a first inlet;
Injecting water or electrolyte into the anode at the second inlet; And
Applying a voltage to the anode and the cathode to decompose the injected water or electrolyte at the anode, and reducing the injected carbon dioxide at the cathode,
An electrolyte membrane is positioned between the anode and the cathode, wherein the electrolyte membrane includes an anion exchange membrane in contact with the cathode and a cation exchange membrane in contact with the anode, and the anion exchange membrane and the cation exchange membrane are in contact with each other to have a junction structure. With
The anion exchange membrane of the electrolyte membrane is a carbon dioxide electrochemical reduction method characterized in that for reducing the amount of hydrogen ions generated while decomposing the water or the electrolyte in the anode to the cathode. The method of claim 7, wherein
The electrolyte solution is KHCO ₃ , K ₂ CO ₃ , KOH, KCl, KClO ₄ , K ₂ SiO ₃ , Na ₂ SO ₄ , NaNO ₃ , NaCl, NaF, NaClO ₄ , CaCl ₂ , guanidinium cation, H ⁺ cation, Alkali metal cations, ammonium cations, alkylammonium cations, halide ions, alkyl amines, borates, carbonates, guanidinium derivatives, nitrites, nitrates, phosphates, polyphosphates, perchlorates, silicates, sulfates, tetraalkyl ammonium salts, or these Carbon dioxide electrochemical reduction method, characterized in that it comprises an aqueous solution containing a mixture of. The method of claim 7, wherein
The carbon dioxide electrochemical reduction method, characterized in that the temperature of the step of reducing the carbon dioxide is 10 ℃ to 100 ℃.

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