KR102154198B1 - Method of preparing metal alloy catalysts, method of reducing carbon dioxide using metal alloy catalysts, and reduction system of carbon dioxide - Google Patents

Abstract

A method of preparing a metal alloy catalyst according to an embodiment of the present invention comprises the steps of preparing a carbon support on which palladium nanoparticles are supported, and a polyol containing ions of palladium and other alloys on a carbon support on which palladium nanoparticles are supported. Dispersing in a solvent to prepare a precursor solution, and irradiating microwaves to the precursor solution to alloy palladium nanoparticles and an alloying metal.

Description

A method of manufacturing a metal alloy catalyst, a method of reducing carbon dioxide using a metal alloy catalyst, and a carbon dioxide reduction system TECHNICAL FIELD BACKGROUND OF THE INVENTION 1.

The present invention relates to a method of manufacturing a metal alloy catalyst, a carbon dioxide reduction method using a metal alloy catalyst, and a carbon dioxide reduction system, and more particularly, a metal alloy that is easy to manufacture and can secure the efficiency and stability of the carbon dioxide reduction reaction. It relates to a method for producing a catalyst, a carbon dioxide reduction method using the same, and a carbon dioxide reduction system.

Recently, as a countermeasure for solving environmental problems caused by exhaustion of carbon-based energy and emission of fuel gas, research on a method of obtaining alternative energy through carbon dioxide conversion has been actively conducted. Among them, electric energy, especially a method of converting carbon dioxide through an electrochemical method, has been widely studied. The electrochemical conversion of carbon dioxide can be converted into various organic substances such as carbon monoxide, formic acid, oxalic acid, methanol, ethanol, and acetaldehyde in an aqueous solution under conditions of room temperature and pressure. In particular, formic acid is a safe, environmentally friendly material with excellent transportability. In addition, formic acid is a material capable of voluntarily converting to hydrogen fuel at room temperature, and is a liquid fuel having excellent connection with hydrogen energy related industries. Therefore, it is important to develop a catalyst having catalytic stability while ensuring such formic acid production efficiency. Here, catalyst stability means maintaining the current density indicating the reaction rate and maintaining the selectivity for the product. However, in the conventional carbon dioxide reduction catalyst technology, a catalyst having stability while securing the production efficiency for formic acid has not been presented.

One of the technical problems to be achieved by the technical idea of the present invention is to provide a method for producing a metal alloy catalyst having improved selectivity for formic acid generation during carbon dioxide reduction and securing stability of the catalyst, and a carbon dioxide reduction method using a metal alloy catalyst. will be.

In addition, one of the technical problems to be achieved by the technical idea of the present invention is to provide a carbon dioxide reduction system including an electrode coated with such a metal alloy catalyst.

The method of manufacturing a metal alloy catalyst according to an embodiment of the present invention comprises the steps of preparing a carbon support on which palladium nanoparticles are supported, the carbon support on which the palladium nanoparticles are supported, including ions of the palladium and other alloy metals. Dispersing in a polyol solvent to prepare a precursor solution, and irradiating microwaves to the precursor solution to alloy the palladium nanoparticles and the alloying metal.

In the carbon dioxide reduction method according to an embodiment of the present invention, preparing a carbon support carrying palladium nanoparticles, the carbon support carrying the palladium nanoparticles in a polyol solvent containing ions of the palladium and other alloy metals. Preparing a precursor solution by dispersion, forming a palladium alloy catalyst by alloying the palladium nanoparticles and the alloy metal by irradiating microwaves to the precursor solution, coating the palladium alloy catalyst on the surface of the first electrode The step, the first electrode, the second electrode, and preparing a reactor for accommodating an electrolyte in which carbon dioxide is dissolved, and applying an electrical signal to the reactor to electrolyze the carbon dioxide dissolved in the electrolyte.

The carbon dioxide reduction system according to the embodiment of the present invention includes a reactor including an electrolyte in which carbon dioxide is dissolved, first and second electrodes in which at least a portion is immersed in the electrolyte, and coated on the surface of the first electrode, and on a carbon support. And a supported palladium-silver (PdAg) alloy nanoparticle catalyst, and a power supply for applying electrical signals to the first and second electrodes so that carbon dioxide is reduced to generate formic acid.

A method of manufacturing a metal alloy catalyst having improved selectivity for formic acid generation during carbon dioxide reduction and ensuring stability of the catalyst, a carbon dioxide reduction method using a metal alloy catalyst, and a carbon dioxide reduction system may be provided.

Various and beneficial advantages and effects of the present invention are not limited to the above-described contents, and may be more easily understood in the course of describing specific embodiments of the present invention.

1A to 1D are views showing a method of manufacturing a metal alloy catalyst according to an embodiment of the present invention.
2 and 3 are graphs showing X-Ray Diffraction (XRD) results of a metal alloy catalyst prepared according to an embodiment of the present invention.
4 is a schematic diagram of a carbon dioxide reduction system according to an embodiment of the present invention.
5 is a diagram for explaining a reaction of a carbon dioxide reduction system.
6A and 6B are graphs showing changes in current density according to a carbon dioxide reduction method according to an exemplary embodiment of the present invention.
7A and 7B are graphs showing Faraday efficiency according to a carbon dioxide reduction method according to an embodiment of the present invention.

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

The embodiments of the present invention may be modified into various different forms or a combination of various embodiments, and the scope of the present invention is not limited to the embodiments described below. In addition, embodiments of the present invention are provided to more completely explain the present invention to those with average knowledge in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation, and elements indicated by the same reference numerals in the drawings are the same elements.

Method for producing a metal alloy catalyst

A method of preparing a metal alloy catalyst according to an embodiment of the present invention includes the steps of: (1) preparing a support on which metal nanoparticles are supported, (2) a support on which the metal nanoparticles are supported, and a metal for an alloy other than the metal. Preparing a precursor solution by dispersing in a solvent containing ions of, and (3) alloying the metal nanoparticles with the alloying metal by irradiating microwaves to the precursor solution. Hereinafter, each step will be described in detail with reference to FIGS. 1A to 1D.

1A to 1D are views showing a method of manufacturing a metal alloy catalyst according to an embodiment of the present invention.

Referring to FIG. 1A, first, a catalyst precursor structure 10 in which metal nanoparticles 15 are supported on a carbon support 12 is prepared.

The carbon support 12 may be provided as a support for increasing the surface area participating in the reaction in the metal nanoparticles 15 functioning as a catalyst. For example, the carbon support 12 includes at least one of carbon black, acetylene black, carbon nanotubes, graphite, graphene, graphite nanofibers, and fullerene. Can include. However, as an example, the carbon support 12 does not necessarily contain carbon, and may be made of a material that does not participate in a reaction in which a metal alloy catalyst is used. The carbon support 12 may have a spherical shape, but is not limited thereto. The carbon support 12 may have, for example, a diameter in the range of about 20 nm to 80 nm.

The metal nanoparticles 15 may be prepared by, for example, chemical synthesis and supported on the carbon support 12 or synthesized to be supported on the carbon support 12. The metal nanoparticles 15 may be made of palladium (Pd), but are not limited thereto, and gold (Au), silver (Ag), platinum (Pt), copper (Cu), mercury It may include at least one of a noble metal such as (Hg) and a transition metal such as titanium (Ti), nickel (Ni), chromium (Cr), and palladium (Pd). The metal nanoparticles 15 may have a diameter in the range of about 1 nm to 10 nm, and in particular, may have a diameter in the range of about 3 nm to 7 nm.

Referring to FIG. 1B, a precursor solution 30 is prepared by dispersing the catalyst precursor structure 10 in a solvent 20 containing ions of an alloying metal.

The solvent 20 may be prepared to contain, for example, polyol. Polyol refers to an alcohol compound containing two or more hydroxyl groups in the molecule. The polyol may prevent aggregation of the catalyst precursor structure 10 and reduce metal ions. Solvent 20 is, for example, ethylene glycol (ethylene glycol), diethylene glycol (diethylene glycol), triethylene glycol (triethylene glycol), propylene glycol (propylene glycol), tetraethylene glycol (tetraethylene glycol), and polyethylene glycol It may include at least one of (polyethylene glycol).

Next, a metal salt containing an alloy metal ion (M ⁿ⁺ ) may be dissolved in the solvent 20. The alloying metal is a metal for forming an alloy with the metal nanoparticles 15, and may be a metal different from the metal nanoparticles 15. The alloy metal is, for example, silver (Ag), iron (Fe), copper (Cu), nickel (Ni), ruthenium (Ru), rhodium (Rh), iridium (Ir), platinum (Pt), bismuth It may contain at least one of (Bi) and lead (Pb). In addition, the metal salt includes a metal cation, nitrate, chloride, trifluoroacetate, bromide, iodide, fluoride, sulfate ), acetate, carbonate, acetylacetoante, oxalate, and hydroxide. In particular, silver trifluoroacetate may be used as the metal salt, whereby the metal ion (M ⁿ⁺ ) for an alloy may become a silver (Ag) cation. The amount of the metal salt added may be controlled so that the molar ratio of the metal for the alloy and the metal constituting the metal nanoparticles 15 is in the range of 0.1:3 to 2.8:3. This is because when the molar ratio of the alloying metal is higher than the above range, a separate single metal phase may be formed without forming an alloy with the metal nanoparticles 15.

The catalyst precursor structure 10 may be dispersed in the precursor solution 30 using an agitation method or a sound wave treatment method.

Referring to FIG. 1C, the precursor solution 30 is irradiated with microwaves 40 to alloy the metal nanoparticles 15 and the alloying metal.

In this step, the alloying metal ions (M ⁿ⁺ ) may be reduced to form an alloy with the metal nanoparticles 15. The processing temperature and processing time in the alloying step have a significant influence on the size uniformity of the finally formed metal alloy nanoparticles. Accordingly, in the present invention, by irradiating the microwave 40 as a heating method, it is possible to uniformly heat in a short time without generating a temperature gradient, so that the uniformity of the metal alloy nanoparticles can be improved. The microwave 40 can use an output in the range of about 50 W to 700 W, and in particular, can be irradiated with an output of about 200 W. The microwave 40 may have a frequency in the range of about 1 kHz to 3000 MHz. The irradiation time of the microwave 40 may be in the range of about 10 seconds to 15 minutes, but is not limited thereto, and may be changed according to the capacity of the precursor solution 30.

In the present invention, the metal nanoparticles 15 are prepared as described above, and the metal nanoparticles 15 are prepared by using a method of reducing other metal ions to the metal nanoparticles 15, while utilizing the microwave 40 to simplify the alloying process. The alloy catalyst can be easily mass-produced.

Referring to FIG. 1D, a metal alloy catalyst structure 10 ′ including the finally prepared metal alloy nanoparticles 16 is shown. The composition ratio of the alloying metal in the metal alloy nanoparticle 16, which is a metal alloy catalyst, may be uniform or different depending on the region. For example, the metal alloy nanoparticles 16 may have an average composition of Pd _x Ag _1-x (here, 0 <x ≤ 0.2) when the alloying metal is silver (Ag), but is not limited thereto. Does not.

2 and 3 are graphs showing X-Ray Diffraction (XRD) results of a metal alloy catalyst prepared according to an embodiment of the present invention.

2, the metal nanoparticle 15 is palladium (Pd), and the alloy metal is shown from the top of the graph, iron (Fe), copper (Cu), nickel (Ni), ruthenium (Ru), rhodium ( Rh), silver (Ag), iridium (Ir), platinum (Pt), bismuth (Bi), lead (Pb) of the metal alloy catalyst structure 10 ′ manufactured according to the above-described manufacturing method with various changes X-ray diffraction pattern analysis results are shown. As shown in the graph, the position of the crystal peak was shifted according to the alloying, and the peak according to the crystal plane of a separate alloying metal was not displayed. From this, it can be seen that according to the method for producing a metal alloy catalyst of the present invention, a metal alloy catalyst with various metals can be prepared.

Referring to FIG. 3, an X-ray diffraction pattern analysis result in the case where the metal nanoparticle 15 is palladium (Pd) and silver (Ag) is used as an alloying metal and the molar ratio is different is shown. On each pattern, the molar ratio of silver (Ag) and palladium (Pd) at the time of manufacture was indicated, and the peak positions of palladium (Pd), palladium-silver (PdAg) alloy, and silver (Ag) were respectively shown at the bottom of the graph. Denoted as.

As shown in the graph, when the molar ratio of silver (Ag) and palladium (Pd) is greater than 2:3, the peak of silver (Ag) appeared separately. When the molar ratio of silver (Ag) and palladium (Pd) is 2:3, the composition in the alloy was analyzed as Pd _0.8 Ag _0.2 . From this, it can be seen that when the molar ratio of the alloying metal is relatively large, a separate phase may be formed or the alloying reaction may be inhibited. Accordingly, the molar ratio of silver (Ag) and palladium (Pd) may be less than a maximum of 3:3, and for example, the maximum molar ratio may be in the range of 2:3 to 2.8:3. In addition, from the above results, it can be seen that according to the method for producing a metal alloy catalyst of the present invention, it is possible to control the element ratio in the metal alloy catalyst.

Carbon dioxide reduction method and carbon dioxide reduction system

The carbon dioxide reduction method according to an embodiment of the present invention includes the steps of (1) preparing a support on which metal nanoparticles are supported, (2) a support on which the metal nanoparticles are supported in a solvent containing ions of an alloying metal. Preparing a precursor solution by dispersing, (3) forming a metal alloy catalyst by alloying the metal nanoparticles with the alloy metal by irradiating microwaves to the solution, (4) using the metal alloy catalyst as a first electrode Coating on the surface of, (5) preparing a reactor for receiving an electrolyte in which the first electrode, the second electrode, and carbon dioxide are dissolved, and (6) applying an electrical signal to the reactor to dissolve in the electrolyte It may include the step of electrolyzing the carbon dioxide. Steps (1) to (3) are steps according to the method of manufacturing the metal alloy catalyst described above with reference to FIGS. 1A to 1D, and thus redundant descriptions will be omitted.

Step (4) is a step of coating the prepared metal alloy catalyst on the surface of an electrode for a carbon dioxide reduction system. Specifically, the metal alloy catalyst structure 10 ′ of FIGS. 1A to 1D is collected in the form of a powder and dispersed in a fluorine-based resin solvent such as Nipion ionomer, and then by a drop-casting method. It can be coated on the electrode. The solvent may be a solvent for dispersing the metal alloy catalyst structure 10 ′ and fixing it to the electrode.

After the metal alloy catalyst is coated on the electrode, in order to activate the surface of the catalyst, a step of selectively dissolving a part of the alloy metal from the metal alloy catalyst may be further performed. Thereby, when the overdeposited alloy metal is present, it can be selectively removed. The dissolving step may use an electrochemical method.

In the step (5), the first electrode coated with the metal alloy catalyst is prepared in a reactor for accommodating an electrolyte in which carbon dioxide is dissolved together with the second electrode to form a carbon dioxide reduction system. This will be described in more detail below with reference to the carbon dioxide reduction system of FIG. 4.

The step (6) is a step of electrolyzing carbon dioxide using a first electrode coated with a metal alloy catalyst. This will be described in more detail below with reference to the reaction schematic diagram of FIG. 5.

4 is a schematic diagram of a carbon dioxide reduction system according to an embodiment of the present invention.

4, the carbon dioxide reduction system 100, a reactor 110, an aqueous electrolyte solution 115, a reference electrode 120, a first electrode (cathode) 130, a second electrode (anode) 140 , And a power supply unit 160 may be included. The reference electrode 120 and the first and second electrodes 130 and 140 may be connected by the power supply unit 160. According to embodiments, the carbon dioxide reduction system 100 may further include a membrane made of an ion-permeable material by dividing the first and second electrodes 130 and 140. In addition, according to embodiments, the carbon dioxide reduction system 100 may further include a product collecting unit and a carbon dioxide supply unit.

The carbon dioxide reduction system 100 may be a system for reducing carbon dioxide in the aqueous electrolyte solution 115 to a product including formic acid. In addition to formic acid, the product may further include carbon monoxide, oxalic acid, methanol, ethanol, acetaldehyde, and the like.

The reactor 110 may be made of a material capable of accommodating the aqueous electrolyte solution 115. The reactor 110 may be made of, for example, pyrex, acrylic, polyvinyl chloride (PVC), or the like.

The electrolyte aqueous solution 115 is accommodated in the reactor 110 and may serve as a source of carbon dioxide and a receptor for protons generated during a reduction reaction of carbon dioxide. The electrolyte aqueous solution 115 may be a solution further comprising at least one of sodium hydrogen carbonate (NaHCo ₃ ), potassium bicarbonate (KHCO ₃ ), and sodium perchlorate (NaClO ₄ ) in distilled water in which carbon dioxide is dissolved. .

The reference electrode 120 may be an electrode for measuring the electrode potential of the first and second electrodes 130 and 140, and there is no particular limitation, but at least one of silver chloride (AgCl), silver (Au), or an alloy thereof is used. Can include. The reference electrode 120 may be positioned on either a cathode or an anode.

Part or all of the first and second electrodes 130 and 140 may be immersed in the aqueous electrolyte solution 115. The first electrode 130 may be a working electrode, and the second electrode 140 may be a counter electrode. Each of the first and second electrodes 130 and 140 may be made of a semiconductor material or a conductive material. For example, the first and second electrodes 130 and 140 are copper (Cu), mercury (Hg), gold (Au), silver (Ag), platinum (Pt), tin (Sn), zinc (Zn) , Iron (Fe), and alloys thereof may include at least one. The first electrode 130 may be a reduction electrode, and the second electrode 140 may be an oxidation electrode.

The first electrode 130 may be prepared by the process of steps (1) to (4) described above. Accordingly, the catalyst layer 150 including the metal alloy catalyst of the present invention may be positioned on at least one surface of the first electrode 130. For example, in one embodiment, the first electrode 130 may be formed of a mirror carbon plate, and the catalyst layer 150 may be a layer coated with a powder of palladium-silver (PdAg) alloy nanoparticles.

The power supply unit 160 may cause a reduction reaction of carbon dioxide to occur by applying an electrical signal to the reactor 110. The power supply unit 160 may be connected to both the reference electrode 120 and the first and second electrodes 130 and 140, or may be connected only to a portion. The voltage applied by the power supply unit 160 may range from 0.2 V to 100 V, but is not limited thereto.

5 is a diagram for explaining a reaction of a carbon dioxide reduction system.

Referring to FIG. 5, when a voltage is applied between the first and second electrodes 130 and 140 in the carbon dioxide reduction system 100, carbon dioxide is reduced in the first electrode 130 and the second electrode 140 Oxygen is generated in the reaction. As described above, the reduction reaction product of carbon dioxide may particularly include formic acid, and the production of carbon monoxide may be minimized. In FIG. 5, on the surface of the metal alloy catalyst, the reaction in which carbon monoxide is produced is shown as pathway (1), and the reaction to produce formic acid is shown as pathway (2). By the metal alloy catalyst according to the present invention, the selectivity of the reaction according to the route (2) may be higher than that according to the route (1). That is, the surface of the metal alloy catalyst may have higher selectivity to oxygen (O) than carbon (C).

Accordingly, the reaction at the first electrode 130 may be expressed by Scheme 1, and the reaction at the second electrode 140 may be expressed by Scheme 2.

[Scheme 1] CO ₂ ^{+ 2 H + + 2 e -} → HCOOH

[Reaction Scheme _{2] H 2 O → 1/2 O} 2 + 2 H + + 2 e -

In the embodiments of the present invention, as a carbon dioxide conversion system, an electrolysis system has been exemplarily described, but the present invention is not limited thereto, and the metal alloy catalyst for reduction of carbon dioxide according to an embodiment of the present invention has various electrochemical reactions. It could be used in systems.

Examples of palladium-silver (PdAg) alloy catalyst

The metal alloy catalyst and carbon dioxide reduction system of an embodiment were prepared as follows.

The metal alloy catalyst was alloyed by dispersing a carbon support on which palladium (Pd) nanoparticles were supported in ethylene glycol containing silver trifluoroacetate, followed by irradiation with microwaves. The powder of the metal alloy catalyst was dispersed in an isopropanol or ethanol solution containing Nafion ionomer solution (5wt%, Sigma Aldrich), and a catalyst ink was prepared by sonication for about 10 minutes. The amount of catalyst in the catalyst ink solution was approximately 6 mg/ml. As an electrode, a mirror carbon plate (Alfa Aesar) was prepared by polishing and washing with deionized water, and then the catalyst ink was drop-cast on the mirror carbon plate. The active area of the electrode was 0.5 cm ² and the amount coated with the catalyst ink was approximately 80 μl. A three-electrode system was prepared using an electrode coated with a metal alloy catalyst as a working electrode, a platinum plate as a counter electrode, an Ag/AgCl electrode as a reference electrode, and a 0.1M HClO ₄ solution saturated with argon gas as an electrolyte. I did. Using cyclic voltammetry, the overdeposited alloy metal was removed by repeating 2 to 8 times at a scan rate of 50 mV/s between -0.35 V and 1.10 V compared to the reference electrode. For carbon dioxide reduction, a system using a platinum (Pt) plate and an Ag/AgCl (3M NaCl) electrode as a counter electrode and a reference electrode, respectively, was used. The electrochemical properties were measured in a two-room electrochemical cell using a CHI potentiostat, and the catholyte and the anolyte were separated using a Nafion ion exchange membrane. The electrolyte solution (0.5 M NaHCO ₃ /0.5 M NaClO ₄ ) was purged with high purity carbon dioxide gas for at least 15 minutes, and the pH after saturation was approximately 7.2. Current was measured over time at each fixed potential, and gaseous products (ie, H ₂ , CO) were analyzed by a gas chromatograph equipped with a thermal conductivity detector (TCD) and a flame ionization detector (FID). The liquid product (HCOOH) was quantified using nuclear magnetic resonance analysis.

6A and 6B are graphs showing changes in current density according to a carbon dioxide reduction method according to an exemplary embodiment of the present invention.

7A and 7B are graphs showing Faraday efficiency according to a carbon dioxide reduction method according to an embodiment of the present invention.

6A and 7A are analysis results for a comparative example in which the metal alloy nanoparticles 16 of FIG. 1D consist only of palladium (Pd), and FIGS. 6B and 7B show the metal alloy nanoparticles 16 are palladium-silver ( PdAg) is an analysis result of an example made of an alloy.

First, referring to FIGS. 6A and 6B, as a result of measuring the current density while changing the voltage for the reference electrode, in the case of the comparative example, the current density showed a tendency to rapidly decrease to a value close to zero in a short time. In contrast, in the case of the embodiment, except for the case of -1.35 V, the result was shown to stably maintain the current density even after the passage of time. However, in the case of -1.35 V, it is difficult to say that the stability of the current density is low because it is due to the current caused by the increase in hydrogen production. This will be described in more detail below with reference to FIGS. 7A and 7B.

When FIG. 7a and FIG. 7b, the embodiment than in comparative analysis of the Faraday efficiency at different potential, for example, relative to the main product, formate (HCOO ^-) in the full potential region increases the efficiency of the carbon monoxide (CO ), it can be seen that the efficiency of In particular, the Faraday efficiency for formic acid was 90% or more at most potentials, and the efficiency was the highest among the products. In addition, in the case of -1.35 V, it can be seen that the Faraday efficiency of hydrogen rapidly increases, and the change in the current density in FIG. 6B can be interpreted as being caused by this.

According to these results, in the case of using the palladium-silver (PdAg) alloy catalyst of the present invention, among the reaction pathways described above with reference to FIG. 5, the reaction proceeding to pathway (1) is induced to pathway (2), It can be understood as improving the production rate. This is understood as a property due to silver (Ag) alloyed with palladium (Pd). Silver (Ag) may be mainly induced OCHO ^* Intermediate than COOH ^* intermediate, which may be one of the binding capacity of (Ag) and the organic molecule. For OCHO ^* , palladium (Pd) and silver (Ag) both have an appropriate level of binding affiity as a catalyst, while for COOH ^* silver (Ag) has a lower binding affinity than palladium (Pd). Therefore, it is possible to control the binding affinity of the entire metal alloy catalyst and to change the reaction path. In addition, in the case of carbon monoxide, there is a problem that the number of active sites for the reaction is continuously reduced by being fixed on the surface of the metal alloy catalyst, but catalyst stability may also be improved by suppressing the generation of carbon monoxide.

The present invention is not limited by the above-described embodiments and the accompanying drawings, but is intended to be limited by the appended claims. Therefore, various types of substitutions, modifications and changes will be possible by those of ordinary skill in the art within the scope not departing from the technical spirit of the present invention described in the claims, and this also belongs to the scope of the present invention. something to do.

100: carbon dioxide reduction system
110: reactor
115: aqueous electrolyte solution
120: reference electrode
130: first electrode
140: second electrode
150: catalyst layer
160: power supply

Claims (10)

Preparing a carbon support on which palladium nanoparticles are supported;
Preparing a precursor solution by dispersing the carbon support on which the palladium nanoparticles are supported in a polyol solvent containing ions of the palladium and other alloy metals; And
A method for producing a metal alloy catalyst comprising the step of alloying the palladium nanoparticles and the alloy metal by irradiating microwaves to the precursor solution.
The method of claim 1,
The alloying metal is a method of manufacturing a metal alloy catalyst of silver (Ag).
The method of claim 1,
Preparing the precursor solution,
A method of producing a metal alloy catalyst comprising dissolving a metal salt containing a cation of the alloy metal in the polyol solvent.
The method of claim 3,
A method of manufacturing a metal alloy catalyst for controlling the amount of the metal salt contained in the precursor solution so that the molar ratio of the alloy metal and the palladium ranges from 0.1:3 to 2.8:3.
The method of claim 1,
The palladium nanoparticles are a method for producing a metal alloy catalyst having a diameter in the range of 1 nm to 10 nm.
Preparing a carbon support on which palladium nanoparticles are supported;
Preparing a precursor solution by dispersing the carbon support on which the palladium nanoparticles are supported in a polyol solvent containing ions of the palladium and other alloy metals;
Irradiating microwaves to the precursor solution to alloy the palladium nanoparticles and the alloying metal to form a palladium alloy catalyst;
Coating the palladium alloy catalyst on the surface of the first electrode;
Preparing a reactor for accommodating the first electrode, the second electrode, and an electrolyte in which carbon dioxide is dissolved; And
A carbon dioxide reduction method comprising the step of electrolyzing carbon dioxide dissolved in the electrolyte by applying an electrical signal to the reactor.
The method of claim 6,
The step of electrolyzing the carbon dioxide comprises applying a reduction potential to the first electrode to generate formic acid.
The method of claim 7,
The Faraday efficiency of formic acid is the largest carbon dioxide reduction method among electrolysis products.
The method of claim 7,
The carbon dioxide reduction method further comprising the step of selectively dissolving and removing a part of the alloy metal from the palladium alloy catalyst so that the palladium alloy catalyst coated on the surface of the first electrode is activated.
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