KR102200031B1 - method for measuring oxygen reduction reaction activity of silver oxide catalyst - Google Patents

Abstract

The present invention relates to a method for electrodeposition of silver oxide nanoparticles, and a method for measuring oxygen reduction reaction activity of a silver oxide catalyst prepared thereby. More particularly, the present invention relates to a method of electrodepositing silver oxide nanoparticles having a uniform pyramid-shaped polyhedral structure and improved catalytic activity on the surface of a working electrode without forming dendrites by applying a current having a positive (+) sign in the form of a pulse, and a method for measuring the activity and electrochemical stability of the silver oxide catalyst prepared by the method in a state in which a triple-phase boundary is formed in the same way as the conditions under which the oxygen reduction catalyst is actually driven.

Description

{Method for measuring oxygen reduction reaction activity of silver oxide catalyst}

The present invention relates to a method for measuring the activity of an oxygen reduction reaction of a silver oxide catalyst, and more specifically, by applying a current having a positive (+) sign in the form of a pulse, it is uniform without dendrite formation. A method of electrodepositing silver oxide nanoparticles with a pyramidal polyhedral structure and improved catalytic activity on the surface of a working electrode, and the activity and electrochemical stability of the silver oxide catalyst produced by the same, as in the conditions under which the oxygen reduction catalyst is actually operated. It relates to a method of measuring in a state where (triple-phase boundary) is formed.

In recent years, due to the oil depletion problem and the effect of global warming, studies on the use of eco-friendly renewable energy and electric vehicles are actively being conducted. Portable mobile devices do not have any problems with the use of existing lithium-ion batteries, but higher capacity is required in the use of electric vehicles, and thus high-efficiency batteries are being studied. Among the batteries researched for this purpose, the metal-air battery has a high energy density, It is eco-friendly because it uses oxygen in the air. Among them, since zinc-air batteries use zinc, they can be used in aqueous electrolytes, and the theoretical energy density is 1085 Wh kg ^-1 , which is higher than that of lithium ion batteries.

An oxygen reduction reaction occurs at the positive electrode of a metal-air battery. The oxygen reduction reaction is a reaction used not only in metal-air cells, but also in fuel cells, and is a reaction that determines the performance and cost of a cell. The oxygen reduction reaction has a slow reaction rate, and a high overvoltage is required due to the strong double bond of oxygen. In order to solve this problem, research on highly active and inexpensive oxygen reduction catalysts is continuously underway.

Platinum, which has high catalytic activity, can also be used as a catalyst in oxygen reduction reactions. However, it is not easy to commercialize due to high cost and low electrochemical stability. For this reason, silver, which is richer and cheaper than platinum, was used to replace the platinum catalyst. Silver can also be developed as a substitute for platinum because it shows relatively high catalytic activity in oxygen reduction reactions in basic electrolytes.

The evaluation of the oxygen reduction reaction catalyst has been performed by a rotating disk electrode (RDE) method. However, this is insufficient for evaluating the activity of the catalyst under the operating conditions of the air cell. In the RDE method, the catalytic activity of the oxygen reduction reaction is measured through convection of dissolved oxygen.In a real battery, the material transfer of oxygen is carried out by diffusion from the external air, so the RDE result is a catalyst under the condition that the anode of the air battery is operated. It cannot be said that it perfectly reflects the activity.

Therefore, in order to compensate for the above-described problem, the present inventors recognized that it is urgent to develop a method for electrodeposition of silver oxide nanoparticles and a method for measuring the activity of the oxygen reduction reaction under conditions in which the silver oxide catalyst produced thereby is actually driven, and completed the present invention. I did.

Republic of Korea Patent Publication No. 10-0413632 Republic of Korea Patent Publication No. 10-0426159

It is an object of the present invention to apply a current having a positive (+) sign in a pulse form, thereby forming a uniform pyramidal polyhedral structure without forming a dendrite, and forming silver oxide nanoparticles with improved catalytic activity on the surface of a working electrode. It is to provide a way to be electrodeposited.

Another object of the present invention is to measure the activity and electrochemical stability of the silver oxide catalyst prepared by the method of electrodeposition of silver oxide nanoparticles under conditions in which a triple-phase boundary is formed as in the actual operating conditions of an oxygen reduction catalyst. To provide a way.

In order to achieve the above object, the present invention provides a method for measuring the oxygen reduction reaction activity of a silver oxide catalyst.

Hereinafter, the present specification will be described in more detail.

The present invention provides a method for measuring the oxygen reduction reaction activity of a silver oxide catalyst comprising the following steps.
(B1) preparing a second electrode cell including a working electrode, a first counter electrode, a reference electrode, and a first electrolyte solution to which silver oxide nanoparticles are electrodeposited;
(B2) forming a triple-phase boundary between the working electrode and the first electrolyte solution; And
(B3) measuring the activity of the silver oxide nanoparticle catalyst by performing cyclic voltammetry on the second electrode cell.
In the present invention, the working electrode to which the silver oxide nanoparticles are electrodeposited is manufactured by the following steps.
(A1) manufacturing a first electrode cell including a working electrode, a second counter electrode, and a second electrolyte solution;
(A2) electrodepositing silver oxide on the working electrode; And

(A3) After completing the step (A2), coating a hydrophobic material on one surface of the working electrode.

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In the present invention, the working electrode is a carbon material or a porous conductor, the first counter electrode and the reference electrode are zinc (Zn), and the second counter electrode is platinum, titanium, a carbon current collector, or stainless steel. ) Connected with an activated carbon cloth (ACC), the first electrolyte solution is a mixed solution of potassium hydroxide (KOH) and zinc oxide (ZnO), and the second electrolyte solution is silver nitrate ( Silver Nitrate, AgNO ₃ ) It is characterized in that the solution.

In the present invention, the carbon material is porous carbon paper (CP), glass carbon (GC), or carbon nanotube, and the porous conductor is stainless steel or metal mesh. To do.

In the present invention, the electrodeposition performed in step (A2) is characterized in that it is performed by a time versus potential method, a time versus current method, or a cyclic potential current method.

In the present invention, the electrodeposition performed in step (A2) is a method of applying a positive current to the working electrode in the form of a pulse.

In the present invention, the hydrophobic material is characterized in that PTFE (polytetrafluoroethylene) or paraffin.

In the present invention, the step (A3) is characterized by consisting of the following steps.

(A3a) coating a hydrophobic material on one surface of the working electrode; And

(A3b) drying the working electrode.

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In the present invention, the three-phase interface is characterized in that it is formed in a meniscus shape.

In the present invention, the cyclic potential current method performed in step (B3) is a method of measuring a current by scanning a voltage in the range of 1.0 to 2.0 V on the working electrode on which the meniscus is formed.

All matters mentioned in the method for electrodeposition of silver oxide nanoparticles and the method for measuring the oxygen reduction reaction activity of the silver oxide catalyst prepared thereby are the same unless contradictory to each other.

The method of electrodepositing silver oxide nanoparticles of the present invention is that by applying a current having a positive (+) sign in a pulse form, the silver oxide nanoparticles have a uniform pyramidal polyhedral structure without the formation of dendrites and have improved catalytic activity. Particles can be electrodeposited.

In addition, since the method for measuring the activity of the silver oxide catalyst of the present invention measures the activity and electrochemical stability of the silver oxide catalyst prepared by the electrodeposition method in a state in which a triple-phase boundary is formed, it is excellent under actual catalyst driving conditions. It is possible to measure the activity of the catalyst with accuracy.

1 is a diagram schematically showing a first electrode cell used in the silver oxide nanoparticle electrodeposition method of the present invention.
Figure 2 is (a) X-ray diffraction (XRD) pattern and (b) Energy Dispersive Spectrometry (EDS) data of silver oxide prepared by the silver oxide nanoparticle electrodeposition method of the present invention. to be.
3 is a Scanning Electron Microscope (SEM) image of silver oxide nanoparticles electrodeposited by the silver oxide nanoparticle electrodeposition method of the present invention.
Figure 4 is a (a) silver oxide nanoparticles electrodeposited by the silver oxide nanoparticle electrodeposition method of the present invention and (b) a comparative example (catalyst (silver oxide nanoparticles) is not electrodeposited on the working electrode (porous carbon paper, CP)) This is a comparison picture of the contact angle of water.
5 is a diagram schematically showing a second electrode cell used in the method for measuring silver oxide catalyst activity of the present invention.
6 is a graph showing the results of the cyclic potential current method for measuring the activity of the silver oxide catalyst of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It will be described in detail focusing on the parts necessary to understand the operation and operation according to the present invention. In describing the embodiments of the present invention, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly convey the gist of the present invention by omitting unnecessary description.

In addition, the technical terms used in the present specification should be interpreted in the meaning generally understood by those of ordinary skill in the technical field to which the present invention belongs, unless otherwise defined in this specification. It should not be construed as a meaning or an excessively reduced meaning.

In addition, the singular expression used in the present specification includes a plurality of expressions unless the context indicates otherwise. In the present application, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various components or various steps described in the specification, and some components or some steps are not included. It should be construed that it may not be, or may further include additional components or steps.

Hereinafter, the present specification will be described in more detail.

Electrodeposition method of silver oxide nanoparticles

The present invention provides a method for electrodepositing silver oxide nanoparticles comprising the following steps.

(A1) manufacturing a first electrode cell including a working electrode, a counter electrode, and an electrolyte solution;

(A2) electrodepositing silver oxide on the working electrode; And

(A3) After completing the step (A2), coating a hydrophobic material on one surface of the working electrode.

Referring to FIG. 1, a first electrode cell including a working electrode, a counter electrode, and an electrolyte solution prepared in step (A1) is schematically illustrated.

The term “working electrode” used in the present invention refers to an electrode used for causing a desired reaction among electrodes used for the purpose of flowing an electric current in a sample when an electrode reaction is caused.

The term “counter electrode” used in the present invention refers to an electrode installed against a working electrode in order to allow current to flow through the electrode.

The term "electrolyte solution" used in the present invention refers to a solution that dissolves in a solvent such as water and dissociates into ions to allow electric current to flow.

The term "electrodeposition" as used in the present invention means a method of depositing a material such as a metal, an alloy, or a compound on an electrode by electrolysis.

The working electrode may be a carbon material or a porous conductor. More specifically, the working electrode is a carbon material composed of porous carbon paper (CP), glass carbon (GC), or carbon nanotubes; Or it may be a porous conductor composed of stainless steel or metal mesh.

Since the working electrode is made of a carbon material or a porous conductor, the electrolyte solution may sufficiently permeate.

The counter electrode may be an inert conductor such as platinum, titanium, a carbon current collector, or an activated carbon cloth (ACC) connected with stainless steel.

The electrolyte solution may be a silver nitrate solution. More specifically, silver in the electrolyte solution may be electrodeposited on the surface of the working electrode as silver oxide or silver by a current flowing in the electrode.

In the present invention, the step (A2) may be a step of electrodepositing silver oxide on the working electrode.

The electrodeposition may be performed by a time versus potential method, a time versus current method, or a cyclic potential current method, and preferably, may be performed by a time versus potential method.

In addition, the electrodeposition may be performed by applying a current having a positive (+) sign in the form of a pulse. More specifically, the electrodeposition may apply a positive current of +30 to +50 mA/cm ^{2, and} the positive current may be applied for a total of 20 to 30 seconds. More specifically, the step (A2) may include a pause while applying the current at +30 to +50 mA/cm ² , and preferably, a current of +30 to +50 mA/cm ² is 1 It is applied for seconds to 3 seconds and may have a rest period for 2 to 6 seconds. For example, when the current is applied for 1 second at +40 mA/cm ² , and can have a pause for 2 seconds, when the current and the pause performed once are 1 cycle, electrodeposition is performed by a total amount of +1 C/cm ² For this, a total of 25 cycles can be performed. Silver oxide particles having a pyramidal polyhedral structure can be electrodeposited in a uniform size by applying a pulse in the manner of applying a current and having a rest period as described above.

In the present invention, step (A3) may be a step of coating a hydrophobic material on one surface of the working electrode.

The hydrophobic material may be PTFE (polytetrafluoroethylene) or paraffin, preferably PTFE, and most preferably 25 to 40% PTFE dispersion.

The step (A3) may impart hydrophobicity to the pores of the catalyst electrode, thereby preventing the electrolyte from overflowing and allowing oxygen to enter and exit smoothly.

The step (A3) may consist of the following steps.

(A3a) coating the hydrophobic material on one surface of the working electrode; And

(A3b) drying the working electrode.

In step (A3a), the hydrophobic material may be coated on one surface of the working electrode. More specifically, a dispersion of 10 to 30 uL of the hydrophobic material per 1 cm ² may be coated 2 to 4 times on one surface of the working electrode.

The coating can be coated after dropping the dispersion of the hydrophobic material onto the glass surface using a micropipette, and coating the dispersion by burying the dispersion on a roller, and coating the hydrophobic material evenly on one surface of the working electrode. If possible, it is not limited thereto.

After performing the step (A3a), a step of drying the working electrode more evenly may be additionally included. The drying may be performed using an infrared lamp.

In the step (A3b), the working electrode may be dried in a high-temperature oven. More specifically, the working electrode may be dried at 90 to 115°C.

Method for measuring oxygen reduction activity of silver oxide catalyst

The present invention provides a method for measuring the oxygen reduction activity of a silver oxide catalyst.

(B1) preparing a second electrode cell including a working electrode, a counter electrode, a reference electrode, and an electrolyte solution to which silver oxide nanoparticles are electrodeposited by the electrodeposition method;

(B2) forming a triple-phase boundary (TPB) between the working electrode and the electrolyte solution; And

(B3) measuring the activity of the silver oxide nanoparticle catalyst by performing a cyclic potential current method on the second electrode cell.

The electrodeposition method is the same as defined in the electrodeposition method of silver oxide nanoparticles, and applies equally as long as all matters mentioned in the electrodeposition method and the activity measurement method do not contradict each other.

In the present invention, the counter electrode and the reference electrode used in step (B1) may be made of zinc (Zn).

In addition, the electrolyte solution may be a mixed solution of potassium hydroxide (KOH) and zinc oxide (ZnO), and more specifically, a mixed solution having a molar ratio of 1 to 10% zinc oxide to the potassium hydroxide. Can be

In the present invention, the (B2) step is a step of forming a triple-phase boundary (TPB) between the working electrode and the electrolyte solution; may be, more specifically, between the working electrode and the electrolyte solution It may be a step of forming a three-phase interface in a meniscus shape.

The term "three-phase interface" as used herein refers to an interface in which three phases of the working electrode in a gaseous oxygen, a liquid electrolyte, and a solid state through which electrons flow simultaneously contact the surface of the silver oxide catalyst.

The term "meniscus" as used herein refers to a curved surface formed when a liquid contacts a solid, and refers to a curved surface formed by a force acting between the solid surface and liquid molecules.

By being formed with the meniscus shape, a reduction reaction of oxygen at the pH of the electrolyte is 4 E mechanisms _{(O 2 + 2H 2 O +} 4e - → 4OH -) or 2 + 2 e mechanisms (O ₂ + H ₂ O + ^{_{2e - → HO 2 - + OH}} -; HO 2 - + H 2 O + 2e - → 3OH -) occurs, and possible oxygen reduction reaction whereby the electrons generated from oxygen, water and the electrode meet at three-phase interface of the catalytic surface Can be set.

Since the more the three-phase interface is formed, the more the oxygen reduction reaction occurs, the greater the absolute value of the reduction current is measured.

In the method of measuring the oxygen reduction reaction activity of the silver oxide catalyst of the present invention, a more three-phase interface can be formed by forming a meniscus on the surface of the working electrode and the electrolyte solution, and as a result, the reduction reaction of oxygen occurs more easily. The absolute value of the current is amplified so that the catalytic activity can be clearly measured.

In the present invention, step (B3) may be a step of measuring the activity of the silver oxide nanoparticle catalyst by performing a cyclic potential current method on the second electrode.

The cyclic potential current method performed in step (B3) may be a method of scanning a voltage range capable of reducing oxygen to the second electrode cell, more specifically, a voltage ranging from 1.0 to 2.0 V. The cyclic potential current method performed in step (B3) scans the voltage at a constant rate and measures the current, and it means that the larger the negative current value, the more reduction reactions occur. That is, the amount of reduced oxygen can be compared with a reduction current value measured at a constant potential, and more specifically, a voltage of 1.0 to 2.0 V, and thus the silver oxide catalyst activity in the oxygen reduction reaction can be measured.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to embodiments described below in detail. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, and only the embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have, and the invention is only defined by the scope of the claims.

The reagents and solvents mentioned below were purchased from Daejung Chemicals & Metals, Korea unless otherwise specified.

Example 1. Silver oxide nanoparticle electrodeposition

Porous carbon paper (CP) having a cross-sectional area of 1 cm ² was used as the working electrode, and activated carbon cloth (ACC) was connected with stainless steel as the counter electrode, and the reference electrode was not set separately. The experiment was conducted with, and the electrolyte solution was 0.05 M AgNO ₃ to prepare a first electrode cell of the present invention. Next, the battery voltage was measured in an open state for 1 hour so that the electrolyte solution sufficiently permeates the working electrode. In addition, a current of +40 mA was applied for 1 second and then held in a resting state (0 mA) for 2 seconds, and silver oxide was electrodeposited by repeating this 25 times, and at this time, the total amount of charge was +1C. After the electrodeposition was completed, the working electrode was washed with distilled water and dried under an infrared lamp. Then, 20 μL of a 30% PTFE dispersion was dropped on a glass plate using a micropipette, spread out, and evenly absorbed on one side of the working electrode, and dried again in an infrared lamp. The above process was repeated once more to coat a total of 40 μL of PTFE dispersion, and finally, the working electrode was dried at 100 °C for 1 hour.

Example 2. Silver oxide catalyst activity measurement

In Example 1, the working electrode electrodeposited with silver oxide was used as a silver oxide catalyst for oxygen reduction reaction to measure the activity.

First, a working electrode electrodeposited with silver oxide in Example 1 was used as the working electrode, and zinc (Zn) was used as the counter electrode and the reference electrode, and the electrolyte solution was potassium hydroxide (KOH) and zinc oxide. A second electrode cell of the present invention was prepared using a mixed solution of Oxide and ZnO). At this time, a meniscus was formed between the working electrode and the electrolyte solution. Next, the activity of the silver oxide catalyst was measured by scanning at a rate of 1 mV s ^-1 in a voltage range of 1.0 to 1.9 V (vs Zn/Zn ²⁺ ).

Experimental Example 1. Confirmation of silver oxide

XRD and EDS were measured to confirm that the metal electrodeposited in Example 1 was silver oxide, and the results are shown in FIG. 2.

Referring to FIG. 2, the peaks of the {111} crystal plane of silver oxide appear at 30.96° and 31.44°, and it can be seen that silver oxide having crystallinity is electrodeposited. In addition, the significant amount of oxygen detected in EDS supports the electrodeposition of silver oxide.

Experimental Example 2. Confirmation of the shape and uniformity of silver oxide electrodeposition

SEM was measured to confirm the shape of the silver oxide electrodeposited in Example 1, uniformity of electrodeposition, and the presence or absence of dendrite formation, and the results are shown in FIG. 3.

Referring to FIG. 3, it can be seen that the silver oxide particles electrodeposited in Example 1 have a pyramid shape. When the silver oxide particles are used as a catalyst, catalytic activity may be increased by intensively exposing crystal planes having high activity on the surface of a polyhedron compared to a spherical catalyst. In addition, it can be seen that silver oxide was uniformly electrodeposited on the entire surface of the electrode, and dendrite was not formed.

Experimental Example 3. Confirmation of water droplet contact angle

The more hydrophilic the sample is, the more it comes into contact with the droplet sample and the contact angle decreases. In alkaline batteries, since the oxygen reduction reaction proceeds with water, the more the electrode is hydrophilic, the more the contact points for the oxygen reduction reaction can be increased. Based on the above contents, the following experiment was performed to confirm the contact angle of the working electrode to which silver oxide was electrodeposited according to Example 1.

First, as a comparative example, water droplets were dropped on the surface of the working electrode (porous carbon paper, CP) to which the metal was not electrodeposited and the working electrode to which silver oxide was electrodeposited according to Example 1, and the contact angle was measured, and the results are shown in FIG. Shown in.

4, (a) In the case of the comparative example, the contact angle was 127.40°, and the water droplets on the sample had the most round shape. On the other hand, (b) in the case of the working electrode electrodeposited with silver oxide according to Example 1, the contact angle was found to be 110.79°. This means that the porous carbon paper electrodeposited with a silver oxide catalyst is more hydrophilic.

Experimental Example 4. Confirmation of catalytic activity

All experimental methods were conducted in the same manner as in Example 2, and the activity of the silver oxide catalyst electrode prepared according to Example 1 and Comparative Examples 1, 2, and 3 differing only in the following configuration was compared, and the results are shown in FIG. Shown in.

-Comparative Example 1: Working electrode coated only with PTFE without electrodeposition of catalyst (porous carbon paper, CP)

-Comparative Example 2: All other experimental methods were the same as in Example 1, but the silver oxide catalyst working electrode not coated with PTFE

-Comparative Example 3: All other experimental methods were the same as in Example 1, but a working electrode with a silver (Ag) catalyst electrodeposited by passing a negative current of -40 mA/cm ²

Referring to FIG. 6, (a) In Comparative Example 1, since there is no silver oxide catalyst, the oxidation-reduction peak of silver existing between 1.4 V-1.9 V vs Zn/Zn ²⁺ is not seen, and there is little oxygen reduction activity. I can. In addition, (b) Comparative Example 2 had a greater oxygen reduction current compared to Comparative Example 1 because silver oxide was electrodeposited, but (d) compared to Example 1, Example 1 coated with hydrophobic PTFE was the comparative example. It can be seen that the oxygen reduction reaction occurs three times more than that of 2. In addition, it can be seen that (d) Example 1 has an oxygen reduction current of four or more times that of Comparative Example 3, and thus, the catalytic activity of silver oxide having a pyramid structure is significantly higher than that of irregular spherical silver.

From the above description, it will be understood that those skilled in the art belonging to the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. In this regard, the embodiments described above are illustrative in all respects, and should be understood as non-limiting.

Claims (12)

(B1) preparing a second electrode cell including a working electrode, a first counter electrode, a reference electrode, and a first electrolyte solution to which silver oxide nanoparticles are electrodeposited;
(B2) forming a triple-phase boundary between the working electrode and the first electrolyte solution; And
(B3) measuring the activity of the silver oxide nanoparticle catalyst by performing a cyclic voltammetry on the second electrode cell; including,
The working electrode on which the silver oxide nanoparticles are electrodeposited,
(A1) manufacturing a first electrode cell including a working electrode, a second counter electrode, and a second electrolyte solution;
(A2) electrodepositing silver oxide on the working electrode; And
(A3) After completing the step (A2), coating a hydrophobic material on one surface of the working electrode; a method for measuring oxygen reduction activity of a silver oxide catalyst, characterized in that. The method of claim 1,
The working electrode is a carbon material or a porous conductor,
The first counter electrode and the reference electrode are zinc (Zn),
The second counter electrode is an activated carbon cloth (ACC) connected with platinum, titanium, a carbon current collector or stainless steel,
The first electrolyte solution is a mixed solution of potassium hydroxide (KOH) and zinc oxide (ZnO),
The second electrolyte solution is a silver nitrate (AgNO ₃ ) solution, characterized in that the oxygen reduction reaction activity measurement method of the silver oxide catalyst. The method of claim 2,
The carbon material is a porous carbon paper (Carbon Paper, CP), a glass carbon (Glassy Carbon, GC) or a carbon nanotube (Carbon NanoTube),
The porous conductor is stainless steel or a metal mesh; Method for measuring the oxygen reduction reaction activity of the silver oxide catalyst, characterized in that. The method of claim 1,
Electrodeposition performed in the step (A2),
A method for measuring the oxygen reduction reaction activity of a silver oxide catalyst, characterized in that it is a time versus potential method, a time versus current method, or a cyclic potential current method. The method of claim 1,
Electrodeposition performed in the step (A2),
A method of applying a positive current to the first electrode cell in the form of a pulse; a method for measuring the oxygen reduction reaction activity of the silver oxide catalyst, characterized in that. The method of claim 1,
The hydrophobic material is PTFE (polytetrafluoroethylene) or paraffin, characterized in that the oxygen reduction reaction activity measurement method of the silver oxide catalyst. The method of claim 1,
The step (A3),
(A3a) coating the hydrophobic material on one surface of the working electrode; And
(A3b) drying the working electrode; method for measuring the oxygen reduction reaction activity of the silver oxide catalyst, characterized in that consisting of. The method of claim 1,
The method for measuring the oxygen reduction reaction activity of the silver oxide catalyst, characterized in that the three-phase interface is formed in a meniscus shape. The method of claim 1,
The cyclic voltammetry method performed in step (B3),
A method of measuring a current by scanning a voltage in the range of 1.0 to 2.0 V through the second electrode cell; a method for measuring the oxygen reduction activity of the silver oxide catalyst. delete delete delete

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