KR100975433B1 - The Micro-Size Hollow Sphere Electrode - Google Patents

Abstract

The present invention relates to a micro-sized pupil electrode having a coatable electrode catalyst on the electrode. Electrode having a micro-sized pupil electrode is capable of high current density operation, and facilitates operation of large electrolytic cells.

Micro pupil, Electrode, Electrochemical cell, Electrolysis system, Fuel cell

Description

The Micro-Size Hollow Sphere Electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow sphere electrode having a micro-electrode catalyst coated on a positive electrode and a negative electrode, which are components of an electrolytic device, a fuel cell, and an electrochemical cell including the same.

      An electrochemical cell is an energy conversion device that is divided into an electrolysis cell that produces oxygen or hydrogen gas using a reactant such as water and a fuel cell that generates electricity using oxygen and hydrogen fuel.

      In general, an electrochemical cell includes an ion exchange membrane separating an reactant produced by an electrochemical reaction at an anode and a cathode, an anode oxidizing a reactant, a cathode reducing a reactant, a separator separating other unit cells, and sealing purposes. It consists of a gasket.

Electrode, which is a core component of electrochemical cell, has an electrode catalyst layer on a substrate, and the electrode catalyst layer is generally an electrochemical catalyst suitable for oxidation and reduction reactions and is composed of platinum group, alloys or oxides thereof. do. The most representative industrial electrode is DSE (Dimensionally Stable Electrode) coated with electrode catalyst such as RuO ₂ -TiO ₂ or RuO ₂ -TiO ₂ -IrO2 on titanium substrate. Due to its high electrode catalytic activity, it has been applied to brine electrolysis or water electrolysis processes. Here, the base material does not participate in the electrode reaction and functions to fix the electrode catalyst layer.

      In addition, the electrode base material is determined in consideration of the bonding with the electrode catalyst applied on the base material, mainly titanium (tanitanium), tantalum (montal), monel (nickel), stainless steel (stainless steel), etc. Is being used. The shape of the electrode base material has a two-dimensional or three-dimensional porous structure to facilitate the inflow and outflow of the reactant electrolyte and the product gas. The two-dimensional shape includes a punched, expanded, mesh, diamond shape hole, the three-dimensional shape by laminating the two-dimensional electrode, There are three-dimensional shapes of fibrous, granular, and particulate powders.

     The conventional representative method of forming an electrode catalyst on a base material is wet processing. This is because the homogeneous liquid catalyst mixture consisting of chloride, alkoxide, and chloride of the electrocatalyst precursor is dispersed on the base material by painting, brushing, or dipping on the base material, and then thermally decomposing it. That's how.

1 is a surface structure of a plate-shaped electrode obtained by a conventional electrode manufacturing method. As shown in FIG. 1, an electrode catalyst is uniformly apply | coated on an electrode base material. Loading amount per unit surface area electrocatalyst is even further performs an iterative process in order to obtain the loading amount of 240μg / cm ² or more of the electrode catalyst in ^two levels of 240μg / cm does not increase the surface area of the electrode catalyst, and thus the activity of the electrode reaction is not increased Do not.

In the electrolytic industry in recent years it has been pursuing the characteristics of the reactor area 2m ² or more large-sized, and 10kA / m ² or more high current density operation in order to maximize productivity and operability, therefore, in the core component of the electrolytic reactor electrodes The required properties also increase the demands on performance and durability (for example, high electrocatalyst loading per unit area and uniform catalyst loading).

With a large area of more than 2m ² , a suitable catalyst loading of 10kA / m ² for current density operation is required to be more than 2,400μg / cm ² , but the conventional method requires that the amount of electrode catalyst loading per unit area is 240μg / cm ² . In the current density operating conditions of 10kA / m ² or more, the life of the electrode is reduced, the electrochemically active capacity is disadvantageous. In addition, S. Pizzini (S. Pizzini, G. Buzzanca, C. Mari, L. Rossi and S. Torchio, Mat. Res. Bull., 7, 449 (1972)), G. Barrel (G. Barrel, J. Guitton, C. Montella, and F. Vergara, Surface Technology), 6, 39 (1977)), K. Kameyama, K. Tsukada, K. Yahikozawa, and Y. Takasu, J. Electrochem. Soc., 140, 966 (1993), etc., reported that the electrode catalyst formation method applying the conventional liquid phase liquid catalyst mixture is greatly affected by the pretreatment process, and the electrode performance is not constant.

      1 S. Pizzini, G. Buzzanca, C. Mari, L. Rossi and S. Torchio, Mat. Res. Bull., 7, 449 (1972)

      G. Barrel, J. Guitton, C. Montella, and F. Vergara, Surface Technology), 6, 39 (1977).

[Reference 3] K. Kameyama, K. Tsukada, K. Yahikozawa, and Y. Takasu, J. Electrochem. Soc., 140, 966 (1993)

Accordingly, the present invention overcomes the limitation of the catalyst loading amount per unit area of 240 μg / cm ^2, which is a characteristic of the electrode prepared by the method of coating a matrix liquid phase liquid catalyst mixture according to the prior art as described above, to 2,400 μg / cm ² By loading up to and improving the heterogeneous distribution of the catalyst over large areas, it is intended to improve the performance and durability of the electrodes so that large area electrochemical cells can be operated at high current densities.

       In order to achieve the above object, the present invention is to provide a structure for a hollow sphere electrode is loaded with an electrochemical catalyst for the purpose of coating the electrode base material.

      In addition, the hollow sphere electrode of the present invention is characterized in that the diameter of 1 to 50μm microunits.

      In addition, the microsphere of the pupil (Hollow Sphere) electrode is characterized in that the electrode base material formed on the base material of the pores constituting the hollow pupil and thereon.

In addition, the catalyst of the hollow sphere electrode of the micro-unit of the present invention is an electrochemical reaction catalyst, and metals and metal oxides such as platinum, iridium, ruthenium, palladium, and tin, which are suitable for the electrochemical reaction of oxidation or reduction, and also their It is characterized by consisting of a compound.

The performance of the electrode coated with the micro-pore electrode of the present invention has a high catalyst loading amount per unit area on the base material, which enables high current density operation, and has a uniform catalyst loading amount distribution on the base material. This is excellent and durability is effective. In addition, high current density operation per unit area becomes possible, which makes the device compact.

      Hereinafter, with reference to the accompanying drawings, a preferred embodiment of a micro-cavity electrode and a method of manufacturing the same and an electrode having the same according to the present invention will be described in detail.

      2 is a conceptual diagram of a micro size pupil electrode of the present invention. As shown in FIG. 2, the micro-sized pupil electrode 100 is composed of a pupil matrix 10 and an electrode catalyst 20.

      The pupil base material 10 supports the electrochemical catalyst and functions to bond with the electrode base material. As the material of the pupil matrix 10, one or more metals selected from the group consisting of gold, silver, chromium, iron, titanium, manganese, cobalt, nickel, molybdenum, tungsten, aluminum, silicon, zinc and tin and Alloys thereof, or oxides thereof are applicable. Considering the bonding property with the electrode base material and the convenience of purchasing raw materials, titanium oxide is preferable.

The electrode catalyst 20 for application to the pupil matrix 10 includes one or more kinds of noble metals composed of Ta, Pb, Ru, Ir, Sn, Ba, Ag, Pt, and Pb applicable to a redox reaction. Mixtures of alloys or oxides thereof, or mixtures of oxides of the catalyst metal and transition metals (Ti, Zr) are suitable.

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       3 is a block diagram illustrating a process 300 of manufacturing a microsized pupil electrode of the present invention. The manufacturing method of the pupil electrode of this invention is possible in the following example, but is not limited to this example.

       As shown in FIG. 3, step 1 is a step of preparing a spherical polymer body, step 2 is a step of forming a pupil matrix to be coated with an electrochemical catalyst on the spherical polymer body, step 3 is a spherical polymer prepared in step 2 A pupil electrode is manufactured by forming a catalyst in the base material of the. The first stage result is 'spherical polymer', the second stage result is 'pupillary base material', and the third stage result is 'pupil electrode'.

      The first step is to obtain a spherical polymer to determine the size of the pupil electrode. In general, methods for preparing spherical polymers include suspension polymerization, emulsion polymerization, seeded polymerizaton, dispersion polymerization, and precipitation polymerization. In consideration of the complexity of the production process, it is preferable to produce spherical particles by emulsion polymerization.

       Suspension polymerization has a problem of having a very large particle size distribution of 0.1 to 1000 μm of the prepared polymer, and seed polymerization has a problem of requiring a long time for polymerization because the polymerization procedure is very difficult and a multi-step polymerization process is required. Polymerization has a difficult problem in that the particles are agglomerated with each other or irregularly shaped particles are formed to form completely crosslinked particles. Finally, precipitation polymerization has a limitation in that the types of monomers available and the solvents used as cosolvents are extremely limited. On the other hand, emulsion polymerization can produce crosslinked polymer particles having a uniform size of about 1 to 10 μm in diameter, and the process is simple.

       Spherical polymer particles having a size of 1 to 100 μm are prepared in a single process polymerization in which a mixture of monomers and a surfactant are polymerized in a solvent at a temperature of 50 to 100 ° C. for 1 to 12 hours at a stirring speed of 10 to 300 rpm.

       As the mixture of the monomers, one or two or more selected from divinylbenzene or acrylate may be used. As an acrylate monomer, 1,2-ethanediol diacrylate; 1,3-propanedioldiacrylate; 1,3-butanedioldiak relate; 1,4-butane diol diacrylate; 1,5-pentanediol diacrylate; 1,6-hexanediol diacrylate; Ethylene glycol diacrylate; Propylene glycol diacrylate; Butylene glycol diacrylate; Triethylene glycol diacrylate; Polyethylene glycol diacrylate; Polypropylene glycol diacrylate; Polybutylene glycol diacrylate; Alkyl acrylates; 1,2- ethanediol dimethacrylate; 1,3-propanediol methacrylate; 1,3-butane dioldimethacrylate; Ethylene glycol dimethacrylate; Propylene glycol dimethacrylate; Butylene glycol dimethacrylate; Triethylene glycol dimethacrylate; Polyethylene glycol dimethacrylate; Polypropylene glycol dimethacrylate; Polybutylene glycol dimethacrylate; Allyl methacrylate; Urethane acrylate; Diallyl maleate and the like can be used.

       As surfactants for reducing aggregates of polymer particles, potassium persulfate, alkyl sulfates, alkylbenzene sulfates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, and PLURONIC type surfactants Etc. can be used.

       The solvent is preferably used as water or an organic solvent capable of dissolving the monomer and water as a cosolvent. The organic solvent that can be used is preferably one or two or more selected from alcohols, ether alcohols, ketones and phenyls. For example, methanol; ethanol; Isopropyl alcohol; Butyl alcohol; Octyl alcohol; Benzyl alcohol; Cyclohexanol; Ethylene glycol; Glinerol; Diethylene glycol; Methyl cellosolve; Cellosolves; Butyl cellosolve; Isopropyl cellosolve; Ethylene glycol monomethyl ether; Ethylene glycol monoethyl ether; Diethylene glycol monomethyl ether; Diethylene glycol monoethyl ether; Acetone; Methyl ethyl ketone; Methyl isobutyl ketone; Chlorobenzene; benzene; Toluene and the like can be used.

       The second step is to prepare a blank base material to form a base material to be coated with a catalyst on the micro-sized spherical polymer particles. The material of the pupil base material that can be formed in the micro-sized spherical polymer particles prepared in step 1 is determined in consideration of the coupling between the electrode base material and the electrode catalyst and the convenience of purchasing raw materials, as described in FIG. Titanium oxide is suitable. The method of forming a titanium oxide film on a spherical polymer is obtained by mixing titanium chloride, titanium lactate, titanium alkoxide, and the like into a spherical polymer, followed by drying and separation.

       In the third step, a micro-sized pupil electrode having a catalytic function is formed to form a catalyst in the resultant pupil matrix.

       The electrode catalyst for application to the pupil matrix is mixed with one or more kinds of noble metal compounds composed of Ta, Pb, Ru, Ir, Sn, Ba, Ag, Pt, and Pb of the electrode catalyst as described in FIG. Or ii) a mixture of one or more compounds of a noble metal compound composed of Ru, Ir, Sn, Pt and Pb, which are precursors of the electrode catalyst, and a transition metal (Ti, Zr) alkoxide. Ultrapure water and acid are added thereto to mix the solution on the pupillary electrode surface, and then dried, followed by pyrolysis to form an electrode catalyst.

       The metal alkoxide is selected from the group consisting of titanium isopropoxide, titanium ethoxide, titanium n-propoxide, titanium butoxide, zirconium n-propoxide, zirconium isopropoxide, zirconium butoxide and zirconium ethoxide. At least one selected is preferred, and the acid is preferably at least one selected from the group consisting of hydrochloric acid, nitric acid, acetic acid and sulfuric acid.

       The drying process removes moisture and organics from the coating layer and affects the physical state of the final coating layer, drying at a temperature of 50-150 ° C. The pyrolysis process completely removes residual organics and crystallizes metal alkoxides and chlorides with metal oxides. To prepare an electrode at a temperature of 400-600 ℃.

       4 is a block diagram illustrating a process of manufacturing an electrode 400 applicable to electrolysis using a microsized pupil electrode. 4 is an example of a manufacturing process of an electrode widely known in the art. As shown in FIG. 4, a coating solution having the micro-sized pupil electrode and electrode catalyst of FIG. 2 prepared by the method shown in FIG. 3 was prepared, ultrapure water and acid were added thereto, and a heterogeneous mixture was added to the base material. It comprises a step of spraying, a step of drying, a firing step of forming an oxide, and the like.

       The process for preparing the electrode catalyst solution is a one-component or two-component complex or multicomponent compound composed of the micro-sized pupil electrode of FIG. 2 prepared by the method shown in FIG. After adding and mixing, one kind of alkoxide of Ti and Zr was diluted 50-100 times in molar ratio to alcohol, and then ultrapure water and acid were added thereto to prepare a coating solution. The molar ratio of one or two chlorides of the noble metals composed of Ru, Ir, Sn, Pt and Pb and one alkoxide of the metal composed of Ti and Zr is 0.4 to 0.6.

      The electrode catalyst solution is sprayed onto the electrode base material by spraying, followed by drying, which is then pyrolyzed. The drying process is dried at a temperature of 50-150 ° C., and the pyrolysis process produces the electrode at a temperature of 400-600 ° C. The thickness of the coating is obtained by adjusting the number of repetitions.

[Example 1]

Example 1 relates to a spherical electrode in which a SnO ₂ electrode catalyst is supported on a hollow sphere TiO ₂ .

1. Manufacturing of micro electrodes

(1) Preparation of spherical polymer

       0.2 g of potassium persulfate is added to 160 ml of distilled water, and the mixture is stirred at 300 rpm while maintaining at 80 ° C. 54 ml of styrene and 2 ml of methacrylic acid were added to the solution for 24 hours in a nitrogen atmosphere.

(2) TiO ₂ production of pupils

Ti (SO ₄ ) ₂ solution was used as a precursor of TiO ₂ . 32 ml of distilled water, 0.8 ml hydrochloric acid, and 1.98 ml of Cetyltrimethylammonium chloride were added to 1.0 ml of the spherical polymer solution prepared above, followed by dispersion for 30 minutes by ultrasound, and 0.18 ml of Ti (SO ₄ ) ₂ solution. Is added dropwise to the solution. The solution was aged for 12 hours at 70 ℃, cooled to room temperature and centrifuged to obtain a solid sample.

(3) Fixation of catalyst SnO ₂ to spherical TiO ₂

A sphere-shaped electrode was prepared by supporting Sn in an amount of 20, 40, and 60 wt% in TiO ₂ . The precursor of Sn used here was used as SnCl ₂ . 32 ml of distilled water, 0.8 ml hydrochloric acid, and 1.98 ml tin chloride (SnCl ₂ ) were added to the spherical TiO ₂ prepared above so that the catalyst was uniformly distributed on the support, followed by dispersion for 30 minutes by ultrasonic waves. The solution was dried at 70 ° C. for 12 hours and then centrifuged to obtain a solid sample. And a solid sample is thermally decomposed at 200-300 degreeC (1 degree-C / min) for 4 hours, and a spherical electrode is manufactured.

(4) physical analysis of pupil-type electrodes

5 is a SEM photograph for the external appearance analysis of the prepared spherical electrode (40wt% Sn / 60wt% TiO ₂ catalyst fired at 300 ° C). As shown in FIG. 5, it can be seen that the size of the prepared pupil electrode is uniformly manufactured to a size of micro units with a size of about 1 μm.

6 is a TEM photograph of the prepared TiO ₂ pupil matrix (100 wt% TiO ₂ ).

FIG. 7 is a TEM photograph showing a catalyst distribution of a manufactured spherical electrode (40 wt% Sn / 60 wt% TiO ₂ calcined at 300 ° C.). It can be seen from the comparison between FIG. 6 and FIG. 7 that the electrode catalyst is uniformly distributed in the size of about 140-200 nm on the pupil matrix.

8 is XRD data showing the distribution of components of a spherical electrode with a change in tin content. As shown in FIG. 8, it can be seen that SnO ₂ and TiO ₂ are formed as the pupil electrode material.

(5) Electrochemical analysis of pupil type electrodes

A catalyst slurry was prepared by adding Nafion (Dupont, 5% aqueous solution), distilled water, and isopropyl alcohol to the prepared pore electrode for performance evaluation of the pore electrode, and dispersing by ultrasonication for 20 minutes. The catalyst was then immobilized on carbon paper to approximately 2,400 μg / cm ² (2.4 mg / cm ² ). 0.01 N sulfuric acid was added to the electrode to facilitate the transfer of charge, and the performance of the spherical electrode manufactured while increasing the potential to 100 mV / S using a potentiometer (WoATech, WPG100) was observed.

9 shows the results of electrochemical evaluation of the performance of the pupil electrode by varying the amount of tin supported. As shown in FIG. 9, 40 wt% Sn / 60 wt% TiO ₂ catalyst TiO ₂ has the highest current density and higher capability than other electrode catalysts. In the following, the best catalyst is represented by Sn (40) / TiO ₂ .

10 compares the performance of a pupil electrode at a firing temperature. As shown in Figure 6, it can be seen that the performance is increased as the firing temperature is increased. The performance of the catalyst was the best at 300 ^o C, the sintering conditions were all fixed to 300 ^o C in the preparation of the pupil electrode of the following examples.

2. Water electrolysis performance

(1) Electrode production for water electrolysis

As starting materials, the pupil electrode Sn (40) / TiO ₂ , iridium chloride, tin chloride, and titanium isopropoxide are used as the weight ratio 0.3: 0.2: 0.2: 0.3. The amount of pupil electrode is based on approximately 240 μg / cm ² (0.24 mg / cm ² ) of catalyst. First, dilute titanium isopropoxide in an alcohol to 50 to 100 times in molar ratio, and then add pupil electrode, iridium chloride, and tin chloride to alcohol. Ultrapure water and hydrochloric acid are added thereto to perform a hydrolysis reaction and a polycondensation reaction to prepare a catalyst slurry.

The catalyst slurry was dispersed in a 3 cm wide and 3 cm long titanium matrix, dried at 100 ° C. using a hot air blower, and calcined at 450-600 ° C. for 10 minutes. In this manner, 10 repetitions were carried out to obtain an electrode on which a catalyst 2,400 μg / cm ² (2.4 mg / cm ² ) was supported. Finally, it was calcined at 450-600 ° C. for 2 hours to obtain an electrode for use in water electrolysis.

(2) water electrolysis experiment

       The electrode was used as a cathode and the platinum electrode was used as a membrane between the anode, the anode and the cathode. Nafion 117 was used to electrolyze the water at 50 ° C. under a zero gap condition with a gap between the cathode and the cathode.

11 is a graph showing a change in voltage according to the current (driving density) applied to the electrode according to the embodiment and the comparative example. The result of Example 1 was expressed as Sn (40) / TiO ₂ . As a result of the examples, the lower the slope of the current density and the voltage curve, the better.

[Example 2]

Example 2 is an example of a spherical electrode in which a Pt electrode catalyst is supported on a hollow sphere TiO ₂ .

1. Manufacturing of micro electrodes

(1) Preparation of spherical polymer

      It prepared in the same manner as in Example 1.

(2) TiO ₂ production of pupils

      It prepared in the same manner as in Example 1.

(3) Fixation of Catalyst Pt on Spherical TiO ₂

However, Pt instead of SnO ₂ was used as the catalyst material, and H ₂ PtCl ₆ was used as a precursor. The rest was prepared in the same manner as in Example 1.

(4) Electrochemical Analysis of Pupil Type Electrode

The rest is analyzed in the same manner as in Example 1, 60 wt% Pt / 40wt% TiO ₂ catalyst has the best ability. The best catalyst below is represented by Pt (60) / TiO ₂ .

FIG. 12 is a TEM photograph showing a catalyst distribution of a manufactured spherical electrode (60 wt% Pt / 40 wt% TiO ₂ calcined at 300 ° C.). It can be seen from the comparison between FIG. 6 and FIG. 12 that the electrode catalyst is uniformly distributed in the size of approximately 140-200 nm on the pupil matrix.

FIG. 13 is XRD data showing a component distribution of a spherical electrode with a change in platinum content. FIG. As shown in FIG. 13, it can be seen that Pt and TiO ₂ are formed as the pupil electrode material.

2. Water electrolysis performance

(1) Electrode production for water electrolysis

As starting materials, the pupil electrode Pt (60) / TiO ₂ , iridium chloride, tin chloride, and titanium isopropoxide were used as the weight ratio 0.3: 0.2: 0.2: 0.3, and the amount of the pupil electrode was approximately 240 μg / cm ² (0.24). mg / cm ² ) was prepared under the same conditions as in Example 1 above.

(2) water electrolysis experiment

       Water was electrolyzed under the same conditions as in Example 1.

Of Example 2 in Figure 11 it was calculated by expressing the result as a Pt (60) / TiO _2.

Example 3

Example 3 relates to a spherical electrode in which an IrO ₂ electrode catalyst is supported on a hollow sphere TiO ₂ .

1. Manufacturing of micro electrodes

(1) Preparation of spherical polymer

       It prepared in the same manner as in Example 1.

(2) TiO ₂ production of pupils

       It prepared in the same manner as in Example 1.

(3) Fixation of catalyst IrO ₂ to spherical TiO ₂

A single catalyst material is IrO ₂ SnO _2, instead, whereby the H ₂ IrCl ₆ was used as a precursor in accordance with. The rest was prepared in the same manner as in Example 1.

(4) Electrochemical Analysis of Pupil Type Electrode

Example 1 in the same manner as the analysis result _{40 wt% IrO 2 / 60wt%} TiO 2 catalyst has the highest capacity. The best catalyst below is represented by IrO ₂ (40) / TiO ₂ .

2. Water electrolysis performance

(1) Electrode production for water electrolysis

As starting materials, the pupil electrode IrO ₂ (40) / TiO ₂ , iridium chloride, tin chloride, and titanium isopropoxide were weight ratio 0.3: 0.2: 0.2: 0.3, and the amount of pupil electrode was approximately 240 μg / cm ² ( 0.24 mg / cm ² ) was prepared under the same conditions as in Example 1 above.

(2) water electrolysis experiment

       Water was electrolyzed under the same conditions as in Example 1.

The result of Example 3 is shown in FIG. 11 as IrO ₂ (40) / TiO ₂ .

Example 4

Example 4 is an example of a spherical electrode in which a RuO ₂ electrode catalyst is supported on a hollow sphere TiO ₂ .

1. Manufacturing of micro electrodes

(1) Preparation of spherical polymer

       It prepared in the same manner as in Example 1.

(2) TiO ₂ production of pupils

       It prepared in the same manner as in Example 1.

(3) Fixation of catalyst RuO ₂ to spherical TiO ₂

However, instead of SnO ₂ as catalyst material, RuO ₂ , and accordingly RuCl ₄ was used as a precursor. The rest was prepared in the same manner as in Example 1.

(4) Electrochemical Analysis of Pupil Type Electrode

Example 1 in the same manner as the analysis result _{20 wt% RuO 2 / 80wt%} TiO 2 catalyst has the highest capacity. The best catalyst below is represented by RuO ₂ (20) / TiO ₂ .

2. Water electrolysis performance

(1) Electrode production for water electrolysis

As starting materials, the pupil electrode RuO ₂ (20) / TiO ₂ , iridium chloride, tin chloride, and titanium isopropoxide were used at a weight ratio of 0.3: 0.2: 0.2: 0.3, and the amount of pupil electrode was approximately 240 μg / cm ² ( 0.24 mg / cm ² ) was prepared under the same conditions as in Example 1 above.

(2) water electrolysis experiment

      Water was electrolyzed under the same conditions as in Example 1.

The result of Example 4 is shown in FIG. 11 as RuO ₂ (40) / TiO ₂ .

Example 5

Example 5 is an example of a spherical electrode in which an IrO ₂ -RuO ₂ electrode catalyst is supported on a hollow sphere TiO ₂ .

1. Manufacturing of micro electrodes

(1) Preparation of spherical polymer

       It prepared in the same manner as in Example 1.

(2) TiO ₂ production of pupils

       It prepared in the same manner as in Example 1.

(3) Fixation of catalyst IrO ₂ -RuO ₂ to spherical TiO ₂

SnO ₂ instead of a single catalyst material is IrO ₂ -RuO _2, In the H ₂ IrCl _6, RuCl ₄ as a precursor was used in the same weight ratio in accordance with. The rest was prepared in the same manner as in Example 1.

(4) Electrochemical Analysis of Pupil Type Electrode

Example 1 In the same analysis results of 30 wt% and IrO _{2 - 30 wt% RuO 2 /} 40wt% TiO 2 catalyst has the highest capacity. The best catalyst below is denoted by IrO ₂ -RuO ₂ (60) / TiO ₂ .

2. Water electrolysis performance

(1) Electrode production for water electrolysis

As starting materials, the pupillary IrO ₂ -RuO ₂ (60) / TiO ₂ , iridium chloride, tin chloride, and titanium isopropoxide were used at a weight ratio of 0.3: 0.2: 0.2: 0.3, and the amount of the pupillary was approximately 240 μg / An electrode was prepared under the same conditions as in Example 1 based on cm ² (0.24 mg / cm ² ).

(2) water electrolysis experiment

      Water was electrolyzed under the same conditions as in Example 1.

The results of Examples 5 to 11 were expressed as _{IrO 2 -RuO 2 (60) /} TiO 2.

[Comparative Example]

       The comparative example relates to an electrode produced by a conventional manufacturing method.

(1) Electrode production for water electrolysis

Iridium chloride, tin chloride and titanium isopropoxide are used as starting materials in a weight ratio of 0.3: 0.4: 0.3. After diluting the titanium isopropoxide in molar ratio 50-100 times in alcohol, iridium chloride and tin chloride are added to alcohol. Ultrapure water and hydrochloric acid are added thereto to perform a hydrolysis reaction and a polycondensation reaction to prepare a catalyst slurry. The catalyst slurry was dispersed in a 5 cm wide and 5 cm long titanium matrix, dried at 100 ° C. using a hot air blower, and calcined at 450-600 ° C. for 10 minutes. 10 repetitions were performed in this manner to obtain an electrode having a catalyst loading of 240 μg / cm ² . Finally, it is calcined at 450-600 ° C. for 2 hours.

(2) water electrolysis experiment

      The electrode was used as a positive electrode and the platinum electrode was used as a membrane between the negative electrode, the positive electrode and the negative electrode. Nafion 117 was used to electrolyze water under a 50 ° C. temperature, and the gap between the positive electrode and the negative electrode was zero gap.

        The results of the comparative example are shown in FIG. 11 as a comparative example.

From the above results, it can be seen that the electrode to which the pupil electrode is applied according to the present invention is superior to the conventional electrode manufactured by the existing method.

       1 is a surface structure of an electrode obtained by a conventional electrode manufacturing method.

       2 is a conceptual diagram of a micro size pupil electrode of the present invention.

      3 is a block diagram illustrating a process 300 of manufacturing a microsized pupil electrode of the present invention.

      4 is a block diagram illustrating a process of manufacturing an electrode 400 applicable to electrolysis using a microsized pupil electrode.

5 is a SEM photograph for the external appearance analysis of the prepared spherical electrode (40wt% Sn / 60wt% TiO ₂ catalyst fired at 300 ° C).

6 is a TEM photograph of the prepared TiO ₂ pupil matrix (100 wt% TiO ₂ ).

FIG. 7 is a TEM photograph showing a catalyst distribution of a manufactured spherical electrode (40 wt% Sn / 60 wt% TiO ₂ calcined at 300 ° C.).

      8 is XRD data showing the distribution of components of a spherical electrode with a change in tin content.

      9 shows the results of electrochemical evaluation of the performance of the pupil electrode by varying the amount of tin supported.

       10 compares the performance of a pupil electrode at a firing temperature.

      11 is a graph showing a change in voltage according to the current (driving density) applied to the electrode according to the embodiment and the comparative example.

FIG. 12 is a TEM photograph showing a catalyst distribution of a manufactured spherical electrode (60 wt% Pt / 40 wt% TiO ₂ calcined at 300 ° C.).

      FIG. 13 is XRD data showing a component distribution of a spherical electrode with a change in platinum content. FIG.

Claims (10)

delete delete delete Method for producing a pupil electrode comprising the following steps: (a) obtaining a solution of spherical polymer particles having a size of 1 to 100 μm by polymerizing in a solution containing a mixture of monomers, a surfactant, and a solvent, (b) dropping and aging a solution containing a TiO ₂ precursor to the spherical polymer solution prepared in step (a) to obtain a spherical TiO ₂ , (c) a catalyst selected from a mixture having the same weight ratio of SnCl ₂ , H ₂ PtCl ₆ , H ₂ IrCl ₆ , RuCl ₄ , H ₂ IrCl _6, and RuCl ₄ in the solution containing the spherical TiO ₂ prepared in step (b) Adding and dispersing a precursor to obtain a spherical electrode, (d) obtaining a spherical pupil electrode by thermal decomposition of the spherical electrode prepared in step (c). As a method of manufacturing a pupil electrode comprising the following steps: (a ′) adding styrene and 2 ml of methacrylic acid to an aqueous solution of potassium persulfate and polymerizing the mixture at 50 to 100 ° C. for 10 to 300 rpm for 1 to 12 hours to obtain a spherical polymer particle solution. (b ') Distilled water, hydrochloric acid and cetyltrimethylammonium chloride ??? are added to the spherical polymer solution prepared in step (a') and dispersed, and then a Ti (SO ₄ ) ₂ solution is added dropwise to the solution. To obtain spherical TiO ₂ by aging and aging, (c ') distilled water, hydrochloric acid and the same weight ratio of SnCl ₂ , H ₂ PtCl ₆ , H ₂ IrCl ₆ , RuCl ₄ , H ₂ IrCl ₆ and RuCl ₄ in the spherical TiO ₂ prepared in step (b') Adding a selected catalyst precursor and then dispersing to obtain a spherical electrode, (d ′) obtaining a spherical pupil electrode by pyrolyzing the spherical electrode prepared in step (c ′) at 400-600 ° C .; The pupil electrode has a diameter of 1 to 50 μm, the catalyst is uniformly distributed in a thickness of 140 to 200 nm on the spherical TiO ₂ pupil substrate, and the loading amount of the catalyst per unit area of the pupil electrode is 2,400 μg / cm ^2. Method of manufacturing a pupil electrode, characterized in that above. Method of producing a electrode for water electrolysis comprising the following steps: (a) obtaining a solution of spherical polymer particles having a size of 1 to 100 μm by polymerizing in a solution containing a mixture of monomers, a surfactant, and a solvent, (b) dropping and aging a solution containing a TiO ₂ precursor to the spherical polymer solution prepared in step (a) to obtain a spherical TiO ₂ , (c) a catalyst selected from the same weight ratio of H ₂ IrCl ₆ and RuCl ₄ in the solution containing the spherical TiO ₂ prepared in step (b), SnCl ₂ , H ₂ PtCl ₆ , H ₂ IrCl ₆ , RuCl ₄ Adding and dispersing a precursor to obtain a spherical electrode, (d) obtaining a spherical pupil electrode by pyrolyzing the spherical electrode prepared in step (c), (e) adding a Nafion aqueous solution, distilled water and isopropyl alcohol to the pupil electrode prepared in step (d) and then dispersing to prepare a catalyst slurry, (f) coating the catalyst slurry on a feeder to immobilize the catalyst on the feeder. As a method of manufacturing an electrode for water electrolysis comprising the following steps: (a ′) adding styrene and 2 ml of methacrylic acid to an aqueous solution of potassium persulfate and polymerizing the mixture at 50 to 100 ° C. for 10 to 300 rpm for 1 to 12 hours to obtain a spherical polymer particle solution. (b ') Distilled water, hydrochloric acid and cetyltrimethylammonium chloride ??? are added to the spherical polymer solution prepared in step (a') and dispersed, and then a Ti (SO ₄ ) ₂ solution is added dropwise to the solution. To obtain spherical TiO ₂ by aging and aging, (c ') A mixture of the same weight ratio of H ₂ IrCl ₆ and RuCl ₄ with distilled water and hydrochloric acid in the spherical TiO ₂ prepared in step (b'), SnCl ₂ , H ₂ PtCl ₆ , H ₂ IrCl ₆ , RuCl ₄ Obtaining a spherical electrode by adding and dispersing a catalyst precursor selected from among (d ′) obtaining a spherical pupil electrode by thermally decomposing the spherical electrode prepared in step (c ′) at 400-600 ° C., (e ') preparing an alcohol solution including the pupil electrode, iridium chloride, tin chloride, and titanium isopropoxide prepared in step (d'), adding ultrapure water and hydrochloric acid to the alcohol solution to hydrolysis reaction and polycondensation Preparing a catalyst slurry by a combined reaction, (f ') dispersing the catalyst slurry prepared in step (e'), followed by drying and firing the titanium base material; The pupil electrode has a diameter of 1 to 50 μm, the catalyst is uniformly distributed in a thickness of 140 to 200 nm on the spherical TiO ₂ pupil substrate, and the loading amount of the catalyst per unit area of the pupil electrode is 2,400 μg / cm ^2. The manufacturing method of the electrode for water electrolysis characterized by the above. 8. The method of claim 7, wherein the step (e ') is performed by diluting titanium isopropoxide in alcohol at a molar ratio of 50 to 100 times, and then adding a pupil electrode, iridium chloride, and tin chloride. Method for producing an electrode. 8. The method of claim 7, wherein the drying and firing in the step (f ') are performed at 50-150 ° C and 450-600 ° C, respectively. The method according to claim 7, wherein the step (e ') is diluted to 50 to 100 times the molar ratio of titanium isopropoxide in alcohol, and then the pupillary electrode prepared in the step (d'), iridium chloride, tin A method for producing an electrolytic electrode, characterized in that a hydrolysis reaction and a polycondensation reaction are carried out by adding a chloride and adding ultrapure water and hydrochloric acid.

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