KR101150215B1 - Multi-layered holow electrode and its preparation method - Google Patents

Abstract

The present invention relates to a micro-sized multi-layered pupil electrode having a coatable electrode catalyst on the electrode and a method of manufacturing the same. The micro-sized multi-layered pupil electrode is capable of high current density operation and facilitates operation of a large electrolytic cell.

Description

Multi-layered holow electrode and its preparation method

The present invention relates to a multi-layered hollow electrode having a microelectrode catalyst coated on a positive electrode and a negative electrode, which are components of an electrolytic device, a fuel cell and an electrochemical cell comprising 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.

The electrode, which is a key component of the electrochemical cell, has a structure having 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, or an alloy or an oxide thereof. The most representative industrial electrode is DSE (Dimensionally Stable Electrode) coated with an electrode catalyst such as RuO ₂ -TiO ₂ or RuO ₂ -TiO ₂ -IrO2 on a titanium carrier. Due to its catalytic activity, it has been applied to brine electrolysis or water electrolysis processes. The carrier does not participate in the electrode reaction and serves to fix the electrode catalyst layer.

In addition, the electrode carrier material is determined in consideration of the bonding with the electrode catalyst applied on the carrier, 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.

A conventional representative method for forming an electrode catalyst on a carrier 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.

Although the electrode catalyst is uniformly coated on the electrode base material in the surface structure of the plate-shaped electrode obtained by the conventional electrode manufacturing method, the loading amount of the electrode catalyst per unit area is 240 μg / cm ^2, and the loading amount of the electrode catalyst is 240 μg / Further performing the repeating process to obtain cm ² or more does not increase the surface area of the electrode catalyst, and thus does not increase the activity of the electrode reaction.

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. 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) et al. Have reported that the electrode catalyst formation method using the conventional liquid phase liquid catalyst mixture is greatly affected by the pretreatment process, and the electrode performance is not constant.

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 particular, the electrical conductivity of the existing TiO ₂ pupil electrode through this has a problem that the electron transfer ability is close to the non-conductor is about 10 ³ ~ 10 ⁸ Ωcm, the present invention intends to overcome this.

In addition, the factors involved in improving the performance of the electrode may include the amount of applied current, the amount of catalyst loading, and the specific surface area of the catalyst. However, these factors are related to the maximization of the electrochemical active surface area. In order to increase the electrochemical response area by changing important geometrical arrangements.

In addition, since the conventional coating method uses TiO 2 as the catalyst binder, the thickness of the catalyst layer has to be reduced in order to maintain the electrical conductivity.

In order to achieve the above object, the present invention provides a means for solving the following problems.

According to one aspect, the present invention discloses a multi-layered pupil electrode, a two-layered or three-layered pupil electrode, and even more than four-layered pupil electrodes may be used according to the necessity.

Specifically, the present invention relates to (i) a first hollow (Ti, Nb) O ₂ carrier and a first (Ti, Nb) O ₂ pupil electrode comprising a first electrochemical catalyst formed on the pupil carrier, and (ii) a multilayer pupil electrode comprising a second hollow (Ti, Nb) O ₂ carrier and a second (Ti, Nb) O ₂ pupil electrode comprising a _second electrochemical catalyst formed on the pupil carrier;

The second (Ti, Nb) O ₂ pupil electrode is located above the first (Ti, Nb) O ₂ pupil electrode; The first (Ti, Nb) O ₂ pupil electrode and the second (Ti, Nb) O ₂ pupil electrode disclose a multilayer pupil electrode, characterized in that the size is different from each other.

Alternatively, the present invention provides (i) a first (Ti, Nb) O ₂ pupil electrode comprising a hollow first pupil (Ti, Nb) O ₂ carrier and a first electrochemical catalyst formed on the pupil carrier, (ii A second hollow (Ti, Nb) O ₂ carrier and a second (Ti, Nb) O ₂ pupil electrode comprising a second electrochemical catalyst formed on the cavity carrier, and (iii) a hollow third pupil A multi-layered pupil electrode comprising a (Ti, Nb) O ₂ carrier and a third (Ti, Nb) O ₂ pupil electrode comprising a third electrochemical catalyst formed on the pupil carrier;

The third (Ti, Nb) O ₂ pupil electrode is located on the second (Ti, Nb) O ₂ pupil electrode, and the second (Ti, Nb) O ₂ pupil electrode is the first (Ti, Nb) O ₂ located above the pupil electrode; The first (Ti, Nb) O ₂ pupil and the second (Ti, Nb) O ₂ pupil are different in size from each other, and the second (Ti, Nb) O ₂ pupil and the third (Ti) , Nb) O ₂ pupil electrode discloses a multilayer pupil electrode, characterized in that the sizes are different from each other.

According to another aspect, the present invention provides a first (Ti, Ti) comprising a (i) feeder, (ii) a hollow first pore (Ti, Nb) O ₂ carrier and a first electrochemical catalyst formed on the pore carrier Nb) O ₂ pupil spherical electrode, and (iii) a hollow second cavity (Ti, Nb) O ₂ carriers and the second (Ti, Nb) O ₂ pupil comprising a second electrochemical catalyst formed on the pupil carrier As a multilayer electrode coated feeder comprising spherical electrodes; The first (Ti, Nb) O ₂ pupil spherical electrode is positioned on the feeder, and the second (Ti, Nb) O ₂ pupil spherical electrode is positioned on the first (Ti, Nb) O ₂ pupil spherical electrode. ; The first (Ti, Nb) O ₂ pupil spherical electrode and the second (Ti, Nb) O ₂ pupil spherical electrode are disclosed in a multi-layer electrode coating feed, characterized in that the size is different from each other.

According to one embodiment, the electrochemical catalyst is selected from Ta, Pb, Ru, Ir, Sn, Ba, Ag, Pt, Pd, mixtures thereof, and oxides thereof.

According to another embodiment, the diameter of the first pupil spherical electrode is 1-20 μm and the diameter of the second pupil spherical electrode is 30-500 μm.

According to another embodiment, the electrochemical catalyst is uniformly distributed in the thickness of 140 ~ 200 nm on the pore carrier, the loading amount of the electrochemical catalyst per unit area of the pupil electrode is 2,400 μg / cm ² or more.

In the present invention, a spherical or fibrous pupil electrode can be used as the pupil electrode, or a spherical pupil electrode and a fibrous pupil electrode can be used in combination with each other. Specifically, at least one spherical pupil electrode may be formed on the spherical pupil electrode, or at least one fibrous pupil electrode may be formed on the fibrous pupil electrode, or at least one fibrous pupil electrode on the spherical pupil electrode. Alternatively, at least one spherical pupil electrode may be formed on the fibrous pupil electrode.

In the present invention, the size of the pupil electrode means the average particle diameter in the sphere in the case of a spherical pupil electrode, and the thickness of the fiber corresponding to the layer thickness in the case of a fibrous pupil electrode.

According to another aspect, the present invention

(a) obtaining a first polymer solution having a size of 1 to 20 μm by polymerizing in a solution containing a mixture of monomers, a surfactant and a solvent,

(b) polymerizing in a solution containing a mixture of a monomer, a surfactant, and a solvent and ultrasonically dispersing to obtain a second polymer solution having a size of 30 to 500 μm,

(c) dropping and aging a precursor solution including Ti and Nb precursors to the first polymer solution or the second polymer solution,

(d) adding and dispersing a catalyst precursor selected from SnCl ₂ , H ₂ PtCl ₆ , H ₂ IrCl ₆ , RuCl ₄ , H ₂ IrCl ₆ , RuCl _4, and a mixture thereof to the first or second polymer aging solution step,

(e) pyrolysing the dispersed solution to obtain a first or second (Ti, Nb) O ₂ pupil spherical electrode,

(f) tert throughout the first 1 (Ti, Nb) O whole of the _second pupil coating the spherical electrode and the second multi-layer electrode comprising a (Ti, Nb) O coating a _second pupil spherical electrode on its top coating grade Disclosed is a manufacturing method.

According to one embodiment, the precursor solution comprises titanium and niobium in a weight ratio of 0.9 to 0.99: 0.01 to 0.1.

According to another embodiment, the precursor solution is a titanium isopropoxide and niobium ethoxide solution is mixed in a weight ratio of 0.9 ~ 0.99: 0.01 ~ 0.1.

According to another embodiment, the catalyst precursor mixture mixes two or more catalyst precursors selected from SnCl ₂ , H ₂ PtCl ₆ , H ₂ IrCl ₆ , RuCl ₄ , H ₂ IrCl ₆ , RuCl ₄ in the same weight ratio.

According to another aspect, the invention discloses a water treatment device or fuel cell comprising a multilayer electrode coated feeder according to the invention.

The present invention discloses a Hollow Sphere electrode loaded with an electrochemical catalyst for the purpose of coating on an electrode carrier. The pupil electrode of the present invention is a (Ti, Nb) O ₂ pupil spherical electrode comprising a hollow pupil (Ti, Nb) O ₂ carrier and an electrochemical catalyst formed on the pupil carrier.

According to one embodiment, the electrochemical catalyst of the present invention is selected from Ta, Pb, Ru, Ir, Sn, Ba, Ag, Pt, Pb, mixtures thereof, and oxides thereof.

As a result, the electrical conductivity of the conventional TiO ₂ pupil was about 10 ³ to 10 ⁸ Ωcm, and the electron transfer ability was low enough to be close to the insulator. In the present invention, by providing a spherical pupil electrode made of titanium dioxide doped with niobium can exhibit excellent electron transfer ability of 10 ^-1 Ωcm or more.

In particular, it was confirmed that by the production method provided by the present invention, the durability of the catalyst was greatly improved in addition to the electron transfer ability, the loading amount and the loading yield of the catalyst were greatly increased, and the uniformity of the catalyst loading was also greatly improved.

According to another embodiment, the diameter of the pupil spherical electrode of the present invention is 1 ~ 50 μm, the electrochemical catalyst is uniformly distributed in the thickness of 140 ~ 200 nm on the pupil carrier, the electric per unit area of the pupil electrode The loading amount of the chemical catalyst is at least 2,400 μg / cm ² .

According to another aspect, the present invention

(a) obtaining a polymer solution 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 precursor solution including Ti and Nb precursors to the polymer solution prepared in step (a);

(c) adding and dispersing SnCl ₂ , H ₂ PtCl ₆ , H ₂ IrCl ₆ , RuCl ₄ , H ₂ IrCl ₆ , RuCl _4, and mixtures thereof to the matured solution;

(d) discloses a method of manufacturing a (Ti, Nb) O ₂ pupil spherical electrode comprising pyrolyzing the dispersed solution.

According to one embodiment, the precursor solution of the present invention comprises titanium and niobium in a weight ratio of 0.9 to 0.99: 0.01 to 0.1.

According to another embodiment, the precursor solution of the present invention is a solution in which a titanium isopropoxide and niobium ethoxide solution are mixed in a weight ratio of 0.9 to 0.99: 0.01 to 0.1.

According to another embodiment, the step (b) is

(b-1) adding distilled water, hydrochloric acid and cetyltrimethylammonium chloride to the polymer solution at a volume ratio of 1:30 to 35: 0.5 to 1: 1.5 to 2.5 and dispersing by ultrasonic for 10 to 40 minutes,

(b-2) dropping the precursor mixed solution to the solution at a volume ratio of 0.1 to 0.3 based on the polymer solution volume;

(b-3) aging the solution at 60-80 ° C. for 10-14 hours.

In particular, the use of titanium isopropoxide and niobium ethoxide as precursors of titanium and niobium, respectively, and cetyltrimethylammonium chloride as emulsifiers, significantly improved catalyst loading, catalyst loading yield, and catalyst loading uniformity. In addition, it was confirmed that the electrode electron transfer capability and electrode durability of the prepared pupil electrode were also improved.

According to another embodiment, it is preferable to further include the step of obtaining the solid sample by cooling the aging solution to room temperature and centrifugation after the step (b-3).

In another embodiment, the catalyst precursor mixture of the present invention is to mix two or more catalyst precursors selected from SnCl ₂ , H ₂ PtCl ₆ , H ₂ IrCl ₆ , RuCl ₄ , H ₂ IrCl ₆ , RuCl ₄ in the same weight ratio. desirable.

According to a specific embodiment, the present invention

(a ′) adding styrene and methacrylic acid to an aqueous solution of potassium persulfate and polymerizing at 50 to 100 ° C. for 100 to 500 rpm for 20 to 30 hours;

(b ′) adding distilled water, hydrochloric acid and cetyltrimethylammonium chloride to the polymerization solution and dispersing it, and then dropping and aging a mixed solution of titanium isopropoxide and niobium ethoxide;

(c ') adding a catalyst precursor selected from distilled water, hydrochloric acid, and a mixture of equal weight ratios of SnCl ₂ , H ₂ PtCl ₆ , H ₂ IrCl ₆ , RuCl ₄ , H ₂ IrCl _6, and RuCl ₄ , and then dispersing the same. step,

(d ') a method of manufacturing a (Ti, Nb) O ₂ pupil spherical electrode comprising pyrolyzing the dispersion solution at 400-600 ° C.,

The pupil spherical electrode has a diameter of 1 to 50 μm, the catalyst is uniformly distributed in the thickness of 140 to 200 nm on the spherical (Ti, Nb) O ₂ pupil matrix, and the loading amount of the catalyst per unit area of the pupil electrode is A method for producing a (Ti, Nb) O ₂ pupil spherical electrode, characterized in that it is 2,400 μg / cm ² or more.

According to another aspect, the invention discloses a water treatment device or fuel cell comprising a (Ti, Nb) O ₂ pupil sphere electrode according to the invention.

In addition, the hollow sphere electrode of the present invention is characterized in that the diameter of 1 ~ 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 microsphere hollow sphere electrode 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 these It is characterized by consisting of a compound of.

The performance of the electrode coated with the micro-pore electrode of the present invention enables high current density operation by having a high catalyst loading amount per unit area on the carrier, and has a uniform catalyst loading distribution on the base material, that is, excellent electrode characteristics, that is, electrode reaction efficiency. This is excellent and durability is effective. In addition, it is possible to operate a high current density per unit area, 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.

The micro-sized pupil of the present invention is composed of a pupil carrier and an electrode catalyst, which supports the electrochemical catalyst and functions to bond with the electrode base material. As the material of the pupil carrier, an alloy with 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, Or oxides thereof. In view of the bonding with the electrode base material and the convenience of purchasing raw materials, titanium oxide is preferable.

The electrode catalyst for application to the pupil carrier is one or a mixture of one or more kinds of noble metals composed of Ta, Pb, Ru, Ir, Sn, Ba, Ag, Pt and Pd applicable to a redox reaction, or It is preferable to mix these oxides or oxides of the above catalyst metals and transition metals (Ti, Zr).

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 ~ 1000 μm of the prepared polymer, seed polymerization has a problem that requires a long time for polymerization because the polymerization process is very difficult and takes a multi-step polymerization process, 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 acrylates may be used. As an acrylate monomer, 1,2-ethanediol diacrylate; 1,3-propanedioldiacrylate; 1,3-butanedioldiak relate; 1,4-butanediol 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.

A step of preparing a pupil carrier is a process of forming a carrier to be coated with a catalyst on the micro-sized spherical polymer particles. The material of the pore base material that can be formed in the micro-sized spherical polymer particles prepared above is determined in consideration of the coupling between the electrode base material and the electrode catalyst and the convenience of purchasing raw materials, and a preferred material is titanium oxide. 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.

Next, in the process of preparing a microsized pupil electrode having a catalytic function, a catalyst is formed on the resulting pupil carrier.

Electrode catalyst for application to the pupil carrier is used by mixing one or more kinds of noble metal compounds composed of Ta, Pb, Ru, Ir, Sn, Ba, Ag, Pt and Pb of the electrode catalyst, or ii) electrode One or more of the compounds of the noble metals composed of Ru, Ir, Sn, Pt, and Pb, which are precursors of the catalyst, and a transition metal (Ti, Zr) alkoxide side are mixed and used. 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 ℃.

Regarding the process of manufacturing the electrode 400 applicable to electrolysis using a micro-sized pupil electrode, a coating solution having a manufactured micro-sized pupil electrode and an electrode catalyst is prepared, and ultrapure water and acid are added thereto. It comprises a step of spraying the heterogeneous mixture on the base material, a step of drying, a firing step of forming an oxide, and the like.

The electrode catalyst solution was prepared by mixing a micro-sized pupil electrode with one or two-component complex or multicomponent compounds composed of chlorides such as Ru, Ir, Sn, Pt, and Pb, followed by mixing, followed by alkoxide 1 of Ti and Zr. After diluting the species in alcohol at a molar ratio of 50-100 times, ultrapure water and acid are 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  One

Preparation Example 1 Preparation of First Spherical Polymer

0.2 g of potassium persulfate was added to 160 ml of distilled water and stirred at 300 rpm while maintaining the temperature at 80 ° C. 54 ml of styrene and 2 ml of methacrylic acid were added to the solution, followed by stirring for 24 hours in a nitrogen atmosphere. At this time, the size of the spherical polymer produced was confirmed to be about 10 ㎛.

Preparation Example 2 Preparation of Second Spherical Polymer

0.2 g of potassium persulfate was added to 160 ml of distilled water and stirred at 300 rpm while maintaining the temperature at 80 ° C. 54 ml of styrene and 2 ml of methacrylic acid were added to the solution, followed by stirring in a nitrogen atmosphere. The size of the spherical polymer droplets was adjusted to 30 to several hundred μm using an ultrasonic disperser.

Preparation Example 3-4: (Ti, Nb) O ₂ Spherical Polymer Produce

As a precursor of (Ti, Nb) O ₂ , Ti isopropoxide solution and Nb ethoxide solution were mixed and used in a weight ratio of 0.96: 0.04. To 1.0 ml of the first and second spherical polymer solutions prepared in Preparation Examples 1 and 2, respectively, 32 ml of distilled water, 0.8 ml of hydrochloric acid, and 1.98 ml of cetyltrimethylammonium chloride were dispersed by ultrasonic wave for 30 minutes, and then Ti-Nb 0.18 ml of the mixed solution was added dropwise to the solution. The solution was aged at 70 ° C. for 12 hours, then cooled to room temperature and centrifuged to obtain first and second (Ti, Nb) O 2 / spherical polymers as solid samples. Solid samples were obtained by applying the same method to the spherical polymers 1 and 2, respectively.

Preparation Example 5-6 Catalyst / (Ti, Nb) O ₂ Manufacture

Dilute titanium isopropoxide and niobium ethoxide in alcohol at a molar ratio of 50 to 100-fold, followed by iridium chloride in alcohol and first and second (Ti, Nb) O 2 / spherical polymers prepared in Preparation Examples 3-4, respectively. After impregnation was separated by centrifugation. This was heat-treated at 400 ° C to prepare first and second (Ti, Nb) O2 pupil electrodes U1 and D1 coated with a catalyst.

Preparation Example 7-8 Catalyst / (Ti, Nb) O ₂ Manufacture

After diluting titanium isopropoxide and niobium ethoxide in alcohol at a molar ratio of 50 to 100 times, palladium chloride in alcohol and first and second (Ti, Nb) O 2 / spherical polymers prepared in Preparation Examples 3-4, respectively. After impregnation was separated by centrifugation. This was heat-treated at 400 ° C. to prepare first and second (Ti, Nb) O 2 pupil electrodes U 2 and D 2 coated with a catalyst.

Example 1 Electrocatalyst Coating

Dilute titanium isopropoxide and niobium ethoxide in isopropyl alcohol at a molar ratio of 50 to 100 times, and then the first and second catalysts / (Ti, Nb) O ₂ pores prepared in Preparation Example 5-6, respectively. Two kinds of coating solutions were prepared by adding electrodes U1 and D1, respectively. After spray-coating the first coating solution on the titanium porous plate used as a feeder and dried at 100 ℃. Thereafter, after spray coating the second coating solution, the same drying was followed by heat treatment at 400 ° C. to prepare a catalyst-coated feeder.

Example 2: Electrocatalyst Coating

The experiment was conducted in the same manner as in Example 1, except that the second coating solution was first coated, and then the first coating solution was coated to prepare a catalyst-coated feeder.

Example  3: electrocatalyst coating

The experiment was conducted in the same manner as in Example 1, except that instead of U1 and D1 prepared in Preparation Example 5-6, U2 and D2 prepared in Preparation Example 7-8 were used to prepare a catalyst-coated feeder. .

Example  4: electrocatalyst coating

The experiment was conducted in the same manner as in Example 3, except that the second coating solution was first coated, and then the first coating solution was coated to prepare a catalyst-coated feeder.

Example  5-8: splicing

The electrode assembly that can be used in a hydroelectrolyte or a fuel cell was manufactured by bonding the feeders and the membranes prepared in Examples 1-4 by hot pressing.

Electrode for Water Electrolysis

As starting materials, the pupillary electrode, iridium chloride, tin chloride, and titanium isopropoxide are used in a weight ratio of 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 alcohol at a molar ratio of 50 to 100 times, 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.

Experimental Example

Physical Analysis of Pupil Electrodes

As a result of SEM photographing for appearance analysis of the prepared electrode, it was confirmed that the size of the prepared pupil electrode was uniformly prepared in the size of micro units with a size of about 1 μm. In addition, it was confirmed that the electrode catalyst was uniformly distributed in the size of approximately 140-200 nm on the pupil support in order to confirm the catalyst distribution.

Electrochemical Analysis of Pupil 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 charge transfer, and the performance of the prepared pupil electrode was observed while increasing the potential to 100 mV / S using a potentiometer (WoATech, WPG100). As a result of performing electrochemical evaluation of the performance of the pupil electrode by changing the amount of tin supported, it was confirmed that the current density was significantly improved than the electrode catalyst.

Water electrolysis performance test

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. As a result, the current density and the slope of the voltage curve were significantly lowered, and it was confirmed that the power reception capability was greatly improved.

Comparative Example 1-3

The experiment was conducted in the same manner as in Example 1, but a pupil was prepared using Ti (SO ₄ ) ₂ , Ti (OMe) ₄ , and Ti (OEt) ₄ as titanium precursors, respectively.

Comparative example  4

The experiment was conducted as in Example 1, but a spherical electrode was prepared using cetylpyridinium chloride in a cationic surfactant instead of cetyltrimethylammonium chloride as an emulsifier (surfactant).

compare Experimental Example  1-4

In Comparative Example 1-3, the yield, by-product generation amount, catalyst activity, durability of the electrode, and the like, which are effectively introduced on the electrode, were significantly lower than those of Example 1-5.

compare Experimental Example  5

In the case of Comparative Example 4, it was confirmed that the catalyst loading amount, catalyst loading yield, and catalyst loading uniformity were greatly reduced compared to Example 1-5.

Although not explicitly described in the above examples, instead of synthesizing the spherical polymer, PS fiber was used to prepare a fibrous multilayer pupil electrode instead of the spherical pupil electrode, and as a result, the results were compared with the spherical pupil electrode.

In addition, a multi-layered multi-layered pupil electrode was prepared by combining spherical and fibrous types, and as a result, the result corresponding to the spherical pupil electrode was confirmed.

1 is a schematic of a pupil electrode coated on a membrane. It is the area where the electrochemical reaction is most active, the specific surface area of the coated catalyst and the effective surface area of the reaction should be wide, and the area where the diffusion layer should exist to facilitate the diffusion of the product. For this reason, it is advantageous to use carriers in the form of pupil electrodes or in the form of fibrous pupil electrodes.

2 and 3 are schematic diagrams of the composite catalyst layer. 2 shows a multi-layer coating on the membrane, and FIG. 3 shows a multi-layer coating on the feeder. The feed-catalyst coated on the feeder of FIG. 3 is again bonded to the membrane, and it can be seen that the unit size of the coating layer adjacent to the membrane layer in both the electrodes of FIGS. 2 and 3 is small.

Claims (12)

delete delete delete delete delete delete (a) obtaining a first polymer solution having a size of 1 to 20 μm by polymerizing in a solution containing a mixture of monomers, a surfactant and a solvent, (b) polymerizing and ultrasonically dispersing in a solution containing a mixture of monomers, a surfactant and a solvent to obtain a second polymer solution having a size of 30 to 500 μm, (c) dropping and aging a precursor solution including Ti and Nb precursors to the first polymer solution or the second polymer solution, (d) adding and dispersing a catalyst precursor selected from SnCl ₂ , H ₂ PtCl ₆ , H ₂ IrCl ₆ , RuCl ₄ , H ₂ IrCl ₆ , RuCl _4, and a mixture thereof to the first or second polymer aging solution step, (e) pyrolysing the dispersed solution to obtain a first or second (Ti, Nb) O ₂ pupil electrode, (f) the full-class wherein the 1 (Ti, Nb) O ₂ coated with a pupil electrode and claim ₂ (Ti, Nb) O 2 process for producing the entire multilayer electrode coating grade, comprising the step of coating the cavity electrode thereon As The precursor solution is a titanium isopropoxide and niobium ethoxide solution is a solution of a multilayer electrode coating feeder, characterized in that the solution is mixed in a weight ratio of 0.9 ~ 0.99: 0.01 ~ 0.1. The method of claim 7, wherein the precursor solution comprises titanium and niobium in a weight ratio of 0.9 to 0.99: 0.01 to 0.1. delete The method of claim 7, wherein the catalyst precursor mixture is a mixture of two or more catalyst precursors selected from SnCl ₂ , H ₂ PtCl ₆ , H ₂ IrCl ₆ , RuCl ₄ , H ₂ IrCl ₆ , RuCl ₄ in the same weight ratio Method for producing a multilayer electrode coating feeder. delete delete

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