KR20160097176A - Amalgam electrode, preparing method thereof, and method of electrochemical reduction of carbon dioxide using the same - Google Patents

Abstract

The present invention relates to a method for producing an amalgam electrode, an amalgam electrode produced thereby, and a method for electrochemically reducing carbon dioxide using the amalgam electrode. To this end, amalgamation is conducted by forming a mercury layer and a metal layer on a surface of a porous base material electrode.

Description

Technical Field [0001] The present invention relates to an amalgam electrode, an amalgam electrode, a method of manufacturing the same, and an electrochemical reduction method of carbon dioxide using the amalgam electrode,

The present invention relates to a method for manufacturing an amalgam electrode, an amalgam electrode produced thereby, and a method for electrochemical reduction of carbon dioxide using the amalgam electrode.

Amalgam is an alloy of mercury and other metals. Since amalgam can be realized as a solid phase with an electrode activity of mercury, studies have been conducted to utilize it as an electrode material. Generally, silver amalgam is used in many cases. Recently, dental amalgam was also applied to electrochemical reduction of carbon dioxide. In all of these cases, amalgamators were used to make amalgamators, which were made by mixing metal powder and mercury at a high speed to form a dough. The amalgam setting reaction, . In particular, dental amalgam is made by mixing mercury and amalgam powder, and amalgam powder is classified as low-copper and high-copper amalgam depending on the content of copper (Cu). For example, the ANA 2000 amalgam powder from Nordiska contains 43.1 wt%, 30.8 wt%, and 26.1 wt% of Ag, Sn, and Cu, respectively. When the amalgam powder is mixed with 55% by weight of liquid mercury and 45% by weight of liquid mercury well, an amalgam for dental use is produced. In this case, a composition of Hg (45 wt%), Ag (24 wt%), Sn (17 wt%) and Cu (14 wt%) is finally made. For example, an amalgam is formed on the surfaces of various types of electrodes, for example, an electrode having a porous structure, thereby realizing electrodes (see, for example, Korean Patent No. 1324742) There is a problem in that it is impossible to apply the method.

The present invention relates to a method for manufacturing an amalgam electrode, an amalgam electrode produced thereby, and a method for electrochemical reduction of carbon dioxide using the amalgam electrode.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

The first aspect of the invention includes electroplating mercury (Hg) and a metal selected from the group consisting of Ag, Sn, Cu, Zn, Pb, Sb, , And a method for manufacturing an amalgam electrode.

A second aspect of the present invention provides an amalgam electrode produced according to the first aspect of the present invention.

A third aspect of the present invention provides a method of electrochemical reduction of carbon dioxide using an amalgam electrode according to the second aspect of the present invention.

According to the present invention, it is possible to constitute a surface-modified electrode by implementing a safe dental amalgam at a level that can ignore toxicity by mercury on various base electrode surfaces. In particular, when an amalgam is applied to a porous structure, And the amalgam electrode having such characteristics can be applied to electrochemical conversion of carbon dioxide, electrochemical generation of hydrogen, and the like, thereby achieving high efficiency.

1A and 1B are schematic views illustrating a method of manufacturing an amalgam electrode according to an embodiment of the present invention.
FIGS. 2 and 3 are graphs showing the voltage and efficiency (%) of a reducing electrode according to a constant current in an electrochemical reduction reaction of carbon dioxide using an amalgam electrode according to an embodiment of the present invention.
4A and 4B are optical microscope photographs showing the surface of an amalgam electrode according to one embodiment of the present invention.
5 is a graph showing X-ray diffraction (XRD) analysis results of the amalgam electrode according to one embodiment of the present invention.
6 is a graph showing an X-ray diffraction (XRD) analysis result of a metal layer on the surface of a base electrode before formation of an amalgam according to an embodiment of the present invention.
FIG. 7 is a graph showing an X-ray diffraction (XRD) analysis result of an amalgam electrode according to an embodiment of the present invention.
8 is a graph showing a current density according to a constant voltage in a hydrogen generation reaction using an amalgam electrode according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

Throughout this specification, when a member is "on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

The terms "about "," substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

The word " step (or step) "or" step "used to the extent that it is used throughout the specification does not mean" step for.

Throughout this specification, the term "combination (s) thereof " included in the expression of the machine form means a mixture or combination of one or more elements selected from the group consisting of the constituents described in the expression of the form of a marker, Quot; means at least one selected from the group consisting of the above-mentioned elements.

Throughout this specification, the description of "A and / or B" means "A or B, or A and B".

Hereinafter, embodiments of the present invention are described in detail, but the present invention is not limited thereto.

The first aspect of the invention includes electroplating mercury (Hg) and a metal selected from the group consisting of Ag, Sn, Cu, Zn, Pb, Sb, , And a method for manufacturing an amalgam electrode. The amalgam according to the present invention may include, but is not limited to, a dental amalgam. The dental amalgam can provide a safe amalgam that can ignore toxicity by mercury, and may include, but is not limited to, Ag ₂ Hg ₃ as a main component.

In one embodiment of the present invention, the substrate electrode may be, but not limited to, a porous substrate, a plate substrate, or a rod-shaped substrate. For example, the porous substrate may include, but is not limited to, a granule aggregate, a surface-treated porous electrode, and a mesh-type metal electrode.

In one embodiment of the invention, the substrate electrode may comprise, but is not limited to, a material selected from the group consisting of copper, tin, nickel, carbon, free carbon, silver, gold, have.

In one embodiment of the present invention, the electroplating is performed by immersing the electrode in a solution containing mercury or the metal, and then electrochemically reducing the mercury or the metal to form a mercury layer on the surface of the substrate electrode But may also include, but not limited to, forming a metal layer.

The mercury according to the present invention or a solution containing the metal may be, but not limited to, containing mercury or ions of the metal. The mercury or ions of the metal may be provided from the mercury or the salts of the metal and the salts may include halides, nitrates, sulphates, sulfamates But are not limited to, alkane sulfonates, alkanol sulfonates, cyanides, acetates, citrates, and the like. For example, the mercury or a solution containing the metal may include, but is not limited to, mercury, such as Hg (NO ₃ ) ₂ , SnSO ₄ , or Ag ₂ SO ₄ , have.

The concentration of the mercury or the metal in the solution containing mercury or the metal according to the present invention may be about 30 mM or less, but it may not be limited thereto. For example, the concentration of mercury or metal in the mercury or metal-containing solution may be about 2 mM or less, about 5 mM or less, about 10 mM or less, about 15 mM or less, about 20 mM or less, about 25 mM or less Or about 30 mM or less, but it may not be limited thereto.

The solution according to the present invention includes an electrolyte, and such an electrolyte is not particularly limited. For example, the electrolyte may include, but is not limited to, electrolytes such as KCN, SC (NH ₂ ) ₂ and H ₂ SO ₄ . The concentration of the electrolyte in the solution according to the present invention may be about 10 M or less, but may not be limited thereto. For example, the concentration of the electrolyte in the solution may be about 0.1 M or less, about 0.2 M or less, about 1 M or less, about 2 M or less, about 5 M or less, or about 10 M or less .

The electrochemical reduction of the electrodeposition according to the present invention can be performed by various methods such as application of a constant voltage or a constant current, or electric potential change. For example, when a constant current is applied during the electrochemical reduction of electrodeposition according to the present invention, the applied value of the constant current may be about 50 mA / cm ² or less, but the present invention is not limited thereto. For example, about 5 mA / cm ² or less, about 8 mA / cm ² or less, from about 10 mA / cm ² or less, from about 15 mA / cm ² or less, from about 20 mA / cm ² or less, from about 25 mA / cm ² or less, about 30 cm ² or less, about 35 mA / cm ² or less, about 40 mA / cm ² or less, about 45 mA / cm ² or less, or about 50 mA / cm ² or less have. For example, the electrochemical reduction of the electrodeposition according to the present invention may employ a constant voltage or a potential change when electrochemical reduction is applied, and the applied value of the constant voltage or the range of the potential change may be about 0.2 V to about 1.2 V : Ag / AgCl). ≪ / RTI > For example, the applied value of the constant voltage or the range of the potential change may be about-0.2 V to about-1.2 V, about-0.2 V to about-1 V, about -0.2 V to about -0.8 V, About 0.4 V to about -1 V, about-0.4 V to about-0.8 V, about -0.4 V to about -0.4 V, about -0.6 V to about -0.4 V, About 0.6 V to about-1.2 V, about-0.6 V to about-1 V, about-0.6 V to about-0.8 V, about-0.8 V to about-1.2 V, about -0.8 V, About-1 V, or about-1 V to about-1.2 V, although the present invention is not limited thereto.

In one embodiment of the present invention, the amalgam electrode manufacturing method comprises: forming a mercury layer on the surface of the base electrode by electrodeposition; Forming a metal layer on the mercury layer by electrodeposition comprising a metal selected from the group consisting of Ag, Sn, Cu, Zn, Pb, Sb, and combinations thereof; And the mercury layer and the metal layer are amalgamated, and the above process may be performed at least once, but the present invention is not limited thereto.

In one embodiment of the present invention, the amalgam electrode includes a metal selected from the group consisting of Ag, Sn, Cu, Zn, Pb, Sb, and combinations thereof by electrodeposition on the surface of the base electrode. To form a metal layer; Forming a mercury layer on the metal layer by electrodeposition; And the metal layer and the mercury layer are amalgamated, and the above process may be performed at least once, but the present invention is not limited thereto.

The thickness of each of the mercury layer and the metal layer according to the present invention may be from about 0.1 mu m to about 2 mu m, but may not be limited thereto. For example, the thickness of each of the mercury layer and the metal layer may be from about 0.1 microns to about 2 microns, from about 0.1 microns to about 1.5 microns, from about 0.1 microns to about 1 micron, from about 0.1 microns to about 0.5 microns, About 0.5 탆 to about 1 탆, about 1 탆 to about 2 탆, about 1 탆 to about 1.5 탆, or about 1.5 탆 to about 2 탆, .

According to the present disclosure, the amalgam electrode may comprise from about 35 to about 55 parts by weight of Hg, from about 14 to about 34 parts by weight Ag, from about 7 to about 17 parts by weight of Sn and from about 4 to about 24 parts by weight of Cu, But may not be limited.

A second aspect of the present invention provides an amalgam electrode, produced by the method according to the first aspect. All of the contents of the first aspect of the present invention can be applied to the amalgam electrode according to the present aspect.

A third aspect of the present invention provides a method for electrochemical reduction of carbon dioxide using an amalgam electrode according to the second aspect. All of the contents of the first and second aspects of the present invention can be applied to the amalgam electrode according to this aspect.

According to an embodiment of the present invention, the electrochemical reduction method of carbon dioxide includes the steps of: supplying a solution containing carbon dioxide to a reducing electrode portion of an electrochemical reactor; And reducing the carbon dioxide by applying a current to the working electrode including the amalgam electrode and the counter electrode. However, the present invention is not limited thereto.

In one embodiment of the invention, the solution may comprise, but is not limited to, an electrolyte selected from the group consisting of KHCO ₃ , NaHCO ₃ , K ₂ SO ₄ , NaCl, KCl, have. The concentration of the electrolyte in the solution according to the present invention may be about 5 M or less, but may not be limited thereto. For example, the concentration of the electrolyte may be about 0.5 M or less, about 1 M or less, about 2 M or less, about 3 M or less, about 4 M or less, or about 5 M or less.

In one embodiment of the invention, the current (current density) may be about 1 mA / cm ² to about 200 mA / cm ² , but may not be limited thereto. For example, the current is approximately 1 mA / cm ² to about 200 mA / cm ^2, about 1 mA / cm ² to about 150 mA / cm ^2, about 1 mA / cm ² to about 100 mA / cm ^2, about 1 mA / cm ² to about 50 mA / cm ^2, from about 50 mA / cm ² to about 200 mA / cm ^2, from about 50 mA / cm ² to about 150 mA / cm ^2, from about 50 mA / cm ² to about 100 mA / cm ^2, about 100 mA / cm ² to about 200 mA / cm ^2, about 100 mA / cm ² to about 150 mA / cm ^2, or about 150 mA / cm ² to about 200 mA / cm ² may be the However, the present invention is not limited thereto.

In the electrochemical reduction method of carbon dioxide according to the present invention, when an amalgam electrode of a plate-like substrate is utilized, it is preferable to use about 5 mA / cm ² To about 10 mA / cm ² It is possible to stably and efficiently perform electrolysis even at a current density of about 10 times or more when the amalgam electrode of a porous substrate is used.

The efficiency of the reduction method according to the present invention can be measured, but not limited thereto, through conversion efficiency to formate.

The current efficiency of the reduction method according to the present application may be about 80% or more, or about 90% or more, but may not be limited thereto.

The conversion from the reduction method according to the present disclosure to the formate may last for about 8 hours or longer, but may not be limited thereto. For example, the conversion from the reduction reaction to the formate may last about 8 hours or more, about 9 hours or more, about 12 hours or more, about 15 hours or more, about 18 hours or more, or about 21 hours or longer, .

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. However, the following examples are given for the purpose of helping understanding of the present invention, but the present invention is not limited to the following examples.

[Example]

Example 1: Porous amalgam electrode to form Ag-Sn layer after Hg layer formation

A mesh type porous copper electrode was impregnated with a 10 mM Hg (NO ₃ ) ₂ solution containing 0.1 M KCN as an electrolyte and then reduced with a constant current of 8 mA / cm ² to remove Hg from the surface of the porous copper electrode To form an Hg layer. An electrode having a very thin Hg layer was placed in a mixed solution of 20 mM SnSO ₄ and 2 mM Ag ₂ SO ₄ containing 0.2 M of SC (NH ₂ ) ₂ and 2 M of H ₂ SO ₄ as an electrolyte, A constant current of 10 mA / cm ² was applied to electrodeposition the Ag-Sn layer. In this case, the counter electrode is a plate Sn electrode. As a result, the amalgam setting reaction of Hg and Ag-Sn proceeded and a solid solid electrode was formed. FIG. 1A is a schematic view showing a manufacturing method of the porous amalgam electrode according to the present embodiment.

Example 2: Porous amalgam electrode forming an Hg layer after formation of an Ag-Sn layer

A mesh type porous copper electrode was impregnated with a mixed solution of 20 mM SnSO ₄ and 2 mM Ag ₂ SO ₄ containing 0.2 M of SC (NH ₂ ) ₂ and 2 M of H ₂ SO ₄ as an electrolyte, A constant current of 10 mA / cm < ² > was applied to form an Ag-Sn layer containing Ag ₃ Sn phase. In this case, a counter electrode is a plate Sn electrode. The electrode on which the Ag-Sn layer was formed was placed in a 10 mM Hg (NO ₃ ) ₂ solution containing 0.1 M KCN electrolyte and subjected to a second electrodeposition by reducing Hg by applying a constant current of 8 mA / cm ² . The amalgam setting of Ag-Sn and Hg resulted in formation of a porous amalgam electrode. FIG. 1B is a schematic view showing a manufacturing method of the porous amalgam electrode according to the present embodiment.

Example 3: Electrochemical reduction method of carbon dioxide using porous amalgam electrode

The porous amalgam electrode prepared in Example 1 was used for electrochemical reduction of carbon dioxide. Specifically, a 0.5 M K ₂ SO ₄ solution, a porous amalgam electrode, and an IrOx coated Ti electrode (counter electrode) were used. A KS RnD 10A constant current was used to apply a constant current to a porous amalgam electrode having an apparent area of 9 cm ² Respectively. Then, the efficiency (current efficiency) and duration of formation of the formate were observed.

(1) 40 mA / cm ² When the current of

When a constant current of 40 mA / cm < ² > was applied to the porous amalgam electrode according to Example 1, a voltage of about 3.6 V was observed at both ends, and the conversion current efficiency to the formate was about 21 hours 90%, and the results are shown in Fig. In addition, it was confirmed that the concentration of the formate salt generated at this time was about 0.5M.

(2) 100 mA / cm ² When the current of

When a constant current of 100 mA / cm < ² > was applied to the porous amalgam electrode according to Example 1, a voltage of about 3.8 V was observed at both ends, and a voltage of about 80% to 90% And the result is shown in FIG. 3. As shown in FIG. In addition, it was confirmed that the concentration of the formate salt generated at this time was about 0.5M.

Experimental Example 1: Optical microscope analysis

The optical microscope analysis of the surface of the porous amalgam electrode prepared in Example 1 was performed using Xi-CAM (Vestek Vision Co., Ltd.), and the results are shown in FIGS. 4A and 4B. As a result of observing the surface of the porous amalgam electrode prepared in Example 1, it can be seen that no copper was observed at all and amalgam was well electrodeposited (Fig. 4a). In a more detailed view, it was confirmed that a porous surface was formed after amalgam production (Fig. 4B).

Experimental Example 2: X-ray diffraction (XRD) analysis

XRD analysis of the porous amalgam electrodes prepared in Examples 1 and 2 was performed using Mini Flex II (Rigaku), and the results are shown in FIGS. 5 to 7. 5 is a graph illustrating the results of the porous amalgam electrode according to the first embodiment. FIG. 6 is a graph illustrating the results of XRD analysis after forming the Ag-Sn layer on the porous copper electrode in the embodiment 2, FIG. 7 shows results of the porous amalgam electrode according to the second embodiment. As a result, it was confirmed that Ag ₂ Hg ₃ phase, which is a main component of dental amalgam, was formed in both experimental examples.

Experimental Example 3: Measurement of electrochemical hydrogen generation using a porous amalgam electrode

Plate amalgam electrodes and the porous amalgam electrodes of Example 1 were used for an electrochemical hydrogen generation experiment (using EG & G 273A Potentiostat (Princeton Applied Research)). When the Ag / AgCl reference electrode was electrochemically applied with a constant voltage of - 2.0 V in a solution containing 0.5 M KHCO ₃ and 2 M KCl, the current density of the plate amorphous electrode was about 10 mA / cm ² , The hydrogen generation reaction proceeded. When the porous amalgam electrode according to Example 1 was used, the current density was about 25 mA / cm < ² > and the hydrogen generation reaction proceeded. Thus, it was confirmed that the porous amalgam electrode can produce an efficient electrolysis system at the same area and at a higher current density than the plate-shaped electrode.

The amalgam electrodes according to the present invention can be applied to porous electrodes by forming an amalgam on the surface of the porous electrode by electrodeposition of a mercury layer and a metal layer, It was confirmed that the porous amalgam electrode exhibits high efficiency in the electrochemical reduction of carbon dioxide and the hydrogen generation reaction using the porous amalgam electrode.

It will be understood by those of ordinary skill in the art that the foregoing description of the embodiments is for illustrative purposes and that those skilled in the art can easily modify the invention without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

Claims (9)

A mercury layer formed by electrodepositing mercury (Hg) and a metal layer formed by electrodeposition of a metal selected from the group consisting of Ag, Sn, Cu, Zn, Pb, Sb and combinations thereof, ≪ / RTI >
Wherein the electrodeposition electrochemically reduces the mercury or the metal after immersing the porous base electrode in a solution containing ions of mercury or ions of the metal.
A method for manufacturing a porous amalgam electrode.
The method according to claim 1,
Wherein the porous substrate electrode comprises a material selected from the group consisting of copper, tin, nickel, carbon, free carbon, silver, gold, and combinations thereof.
The method according to claim 1,
Forming a mercury layer on the surface of the porous base electrode by electrodeposition;
Forming a metal layer on the mercury layer by electrodeposition comprising a metal selected from the group consisting of Ag, Sn, Cu, Zn, Pb, Sb, and combinations thereof; And
The mercury layer and the metal layer are amalgamated
/ RTI >
Wherein the process is performed one or more times.
The method according to claim 1,
Forming a metal layer on the surface of the porous base electrode by electrodeposition comprising a metal selected from the group consisting of Ag, Sn, Cu, Zn, Pb, Sb, and combinations thereof;
Forming a mercury layer on the metal layer by electrodeposition; And
The metal layer and the mercury layer are amalgamated
/ RTI >
Wherein the process is performed one or more times.
A process for the preparation of a compound according to any one of claims 1 to 4,
A porous amalgam electrode formed by amalgamating a mercury layer formed by electrodeposition on a surface of a porous base electrode and a metal layer formed by electrodeposition.
A method for electrochemical reduction of carbon dioxide using a porous amalgam electrode formed by amalgamating a mercury layer formed by electrodeposition and a metal layer formed by electrodeposition on the surface of the porous base electrode according to claim 5.
The method according to claim 6,
Supplying a solution containing carbon dioxide to a reducing electrode portion of an electrochemical reactor; And
Applying a current to the working electrode including the porous amalgam electrode and the counter electrode to reduce carbon dioxide
≪ / RTI >
8. The method of claim 7,
Wherein the solution comprises an electrolyte selected from the group consisting of KHCO ₃ , NaHCO ₃ , K ₂ SO ₄ , NaCl, KCl, and combinations thereof.
8. The method of claim 7,
Wherein the current is 1 mA / cm ² to 200 mA / cm ² .

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