KR20170037778A - Oxidation catalyst for fuel cell, manufacturing method of the oxidation catalyst and fuel cell including the oxidation catalyst - Google Patents

Abstract

The present invention relates to an oxidation catalyst for a fuel cell, a production method thereof, and a fuel cell comprising the oxidation catalyst. The irreversibly adsorbed oxidation catalyst for a fuel cell comprises: a carbon-based support; a gold (Au) nanocore supported on the carbon-based support; and a shell where a platinum (Pt) and an oxidation rate promoting element are irreversibly adsorbed on the gold nanocore. The oxidation catalyst for a fuel cell prevents the generation of catalyst poisons, promotes an oxidation reaction of a direct path, and has excellent catalyst efficiency, thereby implementing an effect of reducing the using amount of the platinum.

Description

TECHNICAL FIELD [0001] The present invention relates to an oxidation catalyst for a fuel cell, a method for manufacturing the same, and a fuel cell including the oxidation catalyst. ≪ Desc / Clms Page number 1 >

The present invention relates to an oxidation catalyst for a fuel cell, a method for producing the same, and a fuel cell including the oxidation catalyst.

Fuel cells are devices that convert chemical energy stored in fuel directly into electrical energy by electrochemical reaction. Generally, a fuel cell includes an electrolyte membrane which functions to conduct electrically charged ions, an electrode (anode and cathode), and a separator functioning as a current collector.

The electrode comprises a catalyst layer made of a catalyst for a fuel cell and a support for supporting the catalyst layer. Specifically, the fuel electrode in the electrode includes a catalyst layer formed of an oxidation catalyst, and the oxidation catalyst acts to oxidize the fuel to generate hydrogen ions, electrons, and the like. The hydrogen ions and electrons thus generated move to the air electrode through the polymer electrolyte membrane and the external circuit, respectively. In the air electrode, oxygen supplied to the air electrode reacts with hydrogen ions and electrons to generate water, and a potential difference is generated as a result of the reaction. Due to the characteristics of such a fuel cell, the generation performance and efficiency are greatly influenced by the activity of the oxidation catalyst.

In general, platinum (Pt) is widely used as an oxidation catalyst. However, the platinum oxidation catalyst is liable to be poisoned by carbon monoxide (CO), which is a reaction intermediate. Therefore, there is an increasing need to develop a technology for solving the problem, and efforts to increase the activity while reducing the amount thereof are increasing.

It is an object of the present invention to provide an oxidation catalyst for a fuel cell capable of preventing the formation of catalyst poisons, oxidizing a direct path, and reducing the amount of platinum used because of excellent catalytic efficiency, And a fuel cell.

One embodiment of the present invention relates to a carbon-based carrier; A gold (Au) nanocore supported on the carbon-based support; And a platinum (Pt) and an oxidation rate promoting element irreversibly adsorbed on the gold nanocore; To an oxidation catalyst for an irreversibly adsorbed fuel cell.

The carbon-based carrier may include at least one of carbon black, activated carbon, carbon nanotube, carbon fiber, fullerene and graphene.

 The gold (Au) nanocore may have an average particle diameter of 1 nm to 100 nm.

The content of the irreversibly adsorbed platinum (Pt) may be 0.04 wt% to 60 wt% of the oxidation catalyst for a fuel cell.

The shell may be a single layer shell in which platinum and an oxidation rate promoting element are irreversibly adsorbed on the gold nanocore.

The shell may have a multi-layered shell structure, and may include an inner shell on which the platinum is irreversibly adsorbed on the gold nanocore, and an outer shell on which the oxidation rate promoting element is irreversibly adsorbed.

The oxidation rate promoting element may be at least one selected from the group consisting of Ru, Cu, Ag, Ge, Sn, Pb, As, Sb, Bi, , Selenium (Se), and tellurium (Te).

According to another embodiment of the present invention, there is provided a method of manufacturing a carbon nanotube, including: a carrier preparation step of supporting a gold nanocore on a carbon carrier; And forming a shell by irreversibly adsorbing platinum (Pt) on the gold nanocore, wherein the shell is formed by irreversibly adsorbing platinum and an oxidation rate promoting element on the gold nanocore to form a single layer shell Manufacturing; Or irreversibly adsorbing platinum on the gold nanocore to form an inner shell and irreversibly adsorbing an oxidation rate promoting element on the inner shell to form an outer shell to produce a multilayer shell, And a manufacturing method thereof.

The method for preparing a support may include preparing a gold (Au) nanocore having an average particle size of 1 nm to 100 nm, and then carrying and supporting the carbon-based support and the gold (Au) nanocore.

The preparation of the single-layered shell is carried out by stirring the carrier, an ionic solution of the platinum ion solution and the oxidation rate-promoting element with stirring, irreversibly adsorbing positive ions of the platinum cation and the oxidation rate-promoting element onto the metallic nanocore, .

The multi-layered shell is produced by stirring the platinum ion solution with the carrier to form an inner shell irreversibly adsorbed on the metal nanocore by the platinum cation, and adsorbing the cation of the oxidation promoting element and the support on which the inner shell is formed Followed by stirring to form an outer shell of irreversibly adsorbed cations of the oxidation rate promoting element.

Another embodiment of the present invention is directed to a fuel cell comprising an oxidizing catalyst for a fuel cell, comprising a fuel electrode coated on a support, a polymer electrolyte membrane bonded on one side with the fuel electrode, and an air electrode bonded on the other side of the polymer electrolyte membrane.

The polymer electrolyte membrane may be formed of a polymer selected from the group consisting of a hydrocarbon-based polymer, a polyimide, a perfluorosulfonic acid polymer, a polysulfone, a polyether sulfone, a polyester, or a polyphosphazene. And may include at least one species.

The anode may be formed by coating a catalyst ink containing the oxidation catalyst for a fuel cell on a support (Catalyst Coated Substrate (CCS)), and the coating method may be selected from electroplating, spraying, painting, doctor blade, And may include at least one species.

The fuel cell may include at least one of a hydrogen fuel cell, a methanol direct liquid fuel cell, an ethanol direct liquid fuel cell, a formic acid direct liquid fuel cell, and a dimethyl ether (DME) direct liquid fuel cell.

The present invention relates to an oxidation catalyst for a fuel cell capable of preventing the formation of a catalyst poison, an oxidation reaction of a direct path, an efficiency of the catalyst being excellent and reducing the amount of platinum used, a method for producing the same, Can be provided.

1 is a view showing an oxidation catalyst for a fuel cell according to one embodiment of the present invention.
2 is a view showing an oxidation catalyst for a fuel cell according to another embodiment of the present invention.
3 is a schematic view showing the structure of a fuel cell according to another embodiment of the present invention.
4 is a transmission electron microscope image of the support of Production Example 1 of the present invention.
5 is a graph showing the results of evaluating the performance of a unit cell according to Example 1 of the present invention and Comparative Example 1. Fig.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the drawings and the following embodiments, but may be embodied in other forms. The embodiments described herein are provided so that those skilled in the art can fully understand the spirit of the present invention. In the drawings, the sizes of the respective regions are exaggerated for the sake of clarity, and unnecessary portions are omitted. Further, like reference numerals designate like elements throughout the specification.

One embodiment of the present invention relates to a carbon-based carrier; A gold (Au) nanocore supported on the carbon-based support; And a platinum (Pt) and an oxidation rate promoting element irreversibly adsorbed on the gold nanocore; To an oxidation catalyst for an irreversibly adsorbed fuel cell. The oxidation catalyst for fuel cells prevents the generation of catalyst poisons, accelerates the oxidation reaction of the direct path, and achieves the effect of reducing the amount of platinum used because of excellent catalyst efficiency.

In general, when a platinum-based catalyst acts as an oxidation catalyst, the oxidation reaction of the fuel can proceed through two routes, direct path and indirect path.

The indirect pathway is a reaction between the fuel and the platinum-based catalyst to produce catalyst-carbon monoxide intermediate (Pt-CO) and H ₂ O. The H ₂ O reacts with the platinum-based catalyst to form catalyst- (CO ₂ ), protons (H ⁺ ), and protons (H ⁺ ) and electrons (e ^- ) are generated, and the catalyst-carbon monoxide intermediate (Pt- And electrons (e ^- ). However, since the hydroxyl group (-OH) in the general operation potential range of the fuel cell is not adsorbed to the platinum-based catalyst, when the unused catalyst-carbon monoxide intermediate (Pt-CO) .

On the other hand, the direct path can convert the fuel directly into carbon dioxide (CO ₂ ), protons (H ⁺ ) and electrons (e ^- ).

The oxidation catalyst for a fuel cell according to an embodiment of the present invention realizes an effect of activating an oxidation reaction through a direct path during the oxidation reaction, thereby achieving excellent activity efficiency and reducing the amount of platinum used.

The oxidation catalyst for a fuel cell of one embodiment includes a carbon-based carrier. In this case, there is an advantageous effect of supporting the gold (Au) nanocore on the surface, and the stability and usability of the catalyst can be improved.

The carbon-based carrier may include at least one of carbon black, activated carbon, carbon nanotube, carbon fiber, fullerene and graphene. In this case, the carrier having the gold (Au) nanocore supported thereon is easy to manufacture, and the stability and usability of the catalyst can be further improved.

The content of the carbon-based support may be, for example, the balance of the oxidation catalyst for a fuel cell excluding the weight of the gold nanocore and the shell.

The oxidation catalyst for a fuel cell of one embodiment includes a gold (Au) nanocore supported on the carbon carrier. The gold nanocore is supported on the carrier in the form of a core to increase the surface area of the catalyst, to fix the carbon carrier and the shell, and to improve the stability of the catalyst. Also, the gold nanocore acts as a junction where irreversible adsorption of platinum and an oxidation promoting element occurs.

The gold (Au) nanocore may have an average particle diameter of 1 nm to 100 nm. In this case, the surface area of the catalyst can be increased, the stability of the catalyst can be further improved, and the activity can be maintained at an excellent level while reducing the amount of irreversibly adsorbed platinum. Such a gold nanocore may be produced by, for example, reducing a solution containing a gold (Au) compound in a solvent.

In the oxidation catalyst for a fuel cell according to an embodiment, the content of the gold (Au) nanocore is 0.01 to 35% by weight, for example, 0.01 to 25% by weight, 0.01 to 15% by weight, %. ≪ / RTI > In this case, the balance between the catalytic activity and the economical efficiency can be excellent.

The oxidation catalyst for a fuel cell of one embodiment includes a shell on which iridium (Pt) is irreversibly adsorbed on the gold nanocore. Thus, the oxidizing catalyst for fuel cell realizes the effect of oxidizing the fuel in the oxidation reaction. The irreversible adsorption can realize a strong binding force so that the amount of platinum used can be reduced while the catalytic activity can be increased to an excellent level. In this case, the effect of stabilizing the catalyst as a whole can be very excellent.

The oxidation catalyst for a fuel cell according to an embodiment includes an irreversibly adsorbed shell of platinum and an oxidation rate promoting element, and a carrier in which such a shell is irreversibly adsorbed on the gold nanocore. Such a carrier is particularly excellent in stability, The effect of promoting the path is very good.

In an oxidation catalyst for a fuel cell according to an embodiment, the shell is a monolayer shell in which platinum and an oxidation rate promoting element are irreversibly co-adsorbed on the gold nanocore; Or a multi-layered shell including an inner shell on which the platinum is irreversibly adsorbed on the gold nanocore, and an outer shell on which the oxidation rate promoting element is irreversibly adsorbed on the inner shell. Both the single-layered shell and the multi-layered shell are irreversibly adsorbed on platinum and oxidation-rate-promoting elements on the gold nano-cores of the above-mentioned carrier. Through this, it is possible to increase the activity to an excellent level while reducing the amount of platinum, Can be improved.

In one embodiment, the shell may be a monolayer shell in which platinum and an oxidation rate promoting element are irreversibly co-adsorbed onto the gold nanocore. In this case, the effect of increasing the catalytic activity can be further improved. An oxidation catalyst for a fuel cell according to an embodiment including such a single-layered shell is shown in Fig. 1, an oxidation catalyst for a fuel cell includes a gold nanocore 11 supported on a carbon-based support 10, and on the gold nanocore 11, a platinum 12 and an oxidation rate promoting element 13) may be formed by irreversible co-adsorption.

In another embodiment, the shell may be a multilayer shell comprising an inner shell on which platinum is irreversibly adsorbed on the gold nanocore and an outer shell on which the oxidation rate promoting element is irreversibly adsorbed. In this case, the effect of increasing the catalyst stability can be further improved. An oxidation catalyst for a fuel cell according to an embodiment including such a multi-layered shell is shown in Fig. 2, the oxidation catalyst for a fuel cell includes a gold nanocore 11 supported on a carbon-based support 10, and an inner portion 12 formed on the gold nanocore 11 by irreversibly adsorbing the platinum 12 And an outer shell formed by irreversibly adsorbing the oxidation rate promoting element 13 on the shell and the inner shell.

In the oxidation catalyst for a fuel cell of one embodiment, the content of the irreversibly adsorbed platinum (Pt) may be 0.04 wt% to 60 wt% of the oxidation catalyst for a fuel cell. In this case, the catalytic activity is more excellent and the balance between the economical efficiency and the catalytic activity can be excellent.

The oxidation rate promoting element may be at least one selected from the group consisting of Ru, Cu, Ag, Ge, Sn, Pb, As, Sb, Bi, , Selenium (Se), and tellurium (Te). These oxidation rate promoting elements can further promote irreversible adsorption to platinum and gold nanocore. In addition, the oxidation rate-promoting element is not only excellent in competitiveness in terms of raw material supply, but also has an excellent effect of promoting direct path during the oxidation reaction. The oxidation rate promoting elements in the above examples may be used singly or in combination of two or more.

In one embodiment, the oxidation rate promoting element may be bismuth (Bi). In this case, the effect of reducing the amount of platinum used can be further improved.

Another embodiment of the present invention relates to a method of manufacturing an oxidation catalyst for a fuel cell as described above, and more particularly, to a method of manufacturing a carrier for supporting a gold nanocore on a carbon carrier, And forming a shell by irreversibly adsorbing platinum (Pt) on the gold nanocore, wherein the shell is formed by irreversibly adsorbing platinum and an oxidation rate promoting element on the gold nanocore to form a single layer shell Manufacturing; Or irreversibly adsorbing platinum on the gold nanocore to form an inner shell, and irreversibly adsorbing an oxidation rate promoting element on the inner shell to form an outer shell to produce a multi-layered shell.

The description of the method for producing the oxidation catalyst for a fuel cell is the same as that described above.

The supporting body manufacturing step may include preparing a gold (Au) nanocore, and then carrying and supporting the carbon-based support and the gold (Au) nanocore. As a result, it is possible to prepare a carrier in which gold nanocore is supported on a carbon-based carrier.

Specifically, the carrier preparation step may include synthesizing a gold (Au) nanocore. The synthesis of such a gold nanocore may be, for example, reducing the gold nanoparticles of a desired size by adding a small amount of a reducing agent while uniformly stirring the stock solution in which the gold precursor is dissolved. The gold precursor may be, for example, chloroauric acid (HAuCl ₄ ) and the reducing agent may be Na ₃ C ₆ H ₅ O ₇ Aqueous solution and Aqueous NaBH ₄ solution. In this case, the yield of the gold nanocore is excellent and the particle size can be easily controlled.

The average particle diameter of the gold (Au) nanocore can be controlled to, for example, 1 nm to 100 nm. In this case, the surface area of the catalyst can be increased, the stability of the catalyst can be further improved, and the activity can be maintained at an excellent level while reducing the amount of irreversibly adsorbed platinum.

In the step of preparing the carrier, a gold nanocore may be supported on the carbon carrier by synthesizing a gold (Au) nanocore, stirring the carbonaceous carrier into a solution in which the gold nanocore is dispersed, and stirring. The dispersion in which the carbon-based support and the gold nanocore are dispersed can be further dispersed by using an ultrasonic generator during the deposition.

The preparation of the single-layered shell is carried out by stirring the carrier, the platinum ion solution and the ionic solution of the oxidation rate-promoting element with stirring, cations of the platinum cation and the oxidation rate-promoting element are irreversibly co-adsorbed on the metallic nanocore, Lt; / RTI >

In this case, the platinum ion solution may be a Pt stock solution containing a platinum precursor, for example, a platinum precursor dissolved in an acidic solution. Further, the ionic solution of the oxidation rate-promoting element may be such that the oxide of the oxidation rate-promoting element is dissolved in the acidic solution.

Specifically, after the carrier prepared as described above is charged into the reactor, the Pt stock solution containing the platinum precursor and the ionic solution of the oxidation accelerating element are slowly added while stirring the cations of the platinum cation and the oxidation promoting element And reacts with the gold nanocore surface of the retardation. Thereafter, the cations of the irreversibly adsorbed platinum cation and the oxidation rate promoting element on the gold nanocore of the carrier are reduced together with the reducing agent. 1, a platinum and oxidation rate promoting element 13 is formed on the surface of the gold nanocore 11 of the carrier on which the gold nanocore 11 is supported on the carbon-based support 10, It is possible to produce an oxidation catalyst for a fuel cell comprising a single-layered shell adsorbed on a support. The single-layered shell produced through this process is irreversibly adsorbed on the metal nanocore, and the stability of the catalyst can be further improved due to the high binding force.

The multi-layered shell is produced by stirring the platinum ion solution with the carrier to form an inner shell irreversibly adsorbed on the metal nanocore by the platinum cation, reducing the inner shell, The cation of the accelerating element may be stirred to irreversibly adsorb the cation of the oxidizing rate promoting element, and the reducing agent may be reduced to form an outer shell.

In this case, the platinum ion solution may be a Pt stock solution containing a platinum precursor, for example, a platinum precursor dissolved in an acidic solution. Further, the ionic solution of the oxidation rate-promoting element may be such that the oxide of the oxidation rate-promoting element is dissolved in the acidic solution.

Specifically, after the carrier prepared as described above is charged into the reactor, the Pt stock solution containing the platinum precursor is slowly added while stirring to form an inner shell irreversibly adsorbed on the surface of the carrier by the platinum cation. Thereafter, the inner shell is reduced with stirring with a reducing agent. Next, the ionic solution of the oxidation rate-promoting element is slowly added to the catalyst having the internal shell formed thereon by stirring, and the cation of the oxidation rate-promoting element is irreversibly adsorbed on the surface of the carrier to form an outer shell. Then, the cations of the oxidation accelerating element of the outer shell are reduced with stirring with the reducing agent. 2, an inner shell in which platinum is irreversibly adsorbed on the surface of the gold nanocore 11 of a carrier on which the gold nanocore 11 is supported on the carbon-based support 10, It is possible to manufacture an oxidation catalyst for a fuel cell of a multi-layered shell including an outer shell in which an element is irreversibly adsorbed. The multi-layered shell prepared through such a process is irreversibly adsorbed on the metal nanocore, so that the stability of the catalyst can be further improved due to the high binding force.

Another embodiment of the present invention relates to a fuel cell including an anode coated with an oxidation catalyst for a fuel cell, a polymer electrolyte membrane bonded on one side with the anode, and an air electrode bonded on the other side of the polymer electrolyte membrane.

Hereinafter, a fuel cell according to another embodiment of the present invention will be described with reference to FIG. The fuel cell 300 of one embodiment includes a polymer electrolyte membrane 230 and a membrane-electrode assembly composed of two electrodes, a fuel electrode and an air electrode. It also includes a separator 260, which serves as a flow path for the fuel and air 261 and serves as a current collector, and a gasket 250 that helps contact the respective electrodes with the flow of fuel and prevents leaks of fuel and air .

The fuel cell 300 of this embodiment may be a unit cell. Further, the unit cell may be a multilayer stack formed by repeatedly bonding the unit cells.

The fuel cell may include at least one of a hydrogen fuel cell, a methanol direct liquid fuel cell, an ethanol direct liquid fuel cell, a formic acid direct liquid fuel cell, and a dimethyl ether (DME) direct liquid fuel cell.

Specifically, the membrane-electrode assembly may have a fuel electrode formed on one side of the polyelectrolyte membrane 230 and an air electrode formed on the other side thereof. The anode may be an electrode for oxidizing the fuel, and may include the oxidation catalyst layer 220 including the oxidizing catalyst for a fuel cell of the present invention. The oxidation catalyst layer 220 may be formed by coating on the support 210, for example. The support 210 may be made of, for example, porous carbon paper or carbon cloth. In addition to the support for supporting the catalyst layer, the support 210 serves as a gas diffusion layer for diffusing the reactive gas into the catalyst layer and a current collector for moving the current generated in the catalyst layer to the separator. And also serves as a passage through which the generated water flows out of the catalyst bed. The air electrode is an electrode for reducing oxygen, and may include a reducing catalyst layer including a reducing catalyst. The reduction catalyst layer may be coated on a support provided on the other side of the polymer electrolyte membrane 230.

Specifically, the oxidation catalyst layer 220 is prepared by preparing a catalyst ink prepared by mixing the above-described oxidation catalyst for a fuel cell of the present invention, water, a solvent, an ionomer and the like, and coating the catalyst on a support 220 (Catalyst Coated Substrate . At this time, the method of coating the catalyst ink on the support may be an electroplating method, a spraying method, a painting method, a doctor blade method, a screen printing method, or the like. Alternatively, the catalyst ink may be directly coated on the polymer electrolyte membrane 230 (Catalyst Coated Membrane (CCM)).

The membrane-electrode assembly includes a polymer electrolyte membrane 230 positioned between the fuel electrode (oxidation electrode) and the air electrode (reduction electrode). When the membrane-electrode assembly is compressed at a high temperature and a high pressure using a hot press, the contact between each of the electrodes and the polymer electrolyte membrane 230 can be improved to reduce the contact resistance between the fuel electrode, the electrolyte membrane, and the air electrode and the electrolyte membrane .

The polymer electrolyte membrane 230 may be formed of a hydrocarbon polymer, a polyimide, a perfluorosulfonic acid polymer, a polysulfone, a polyethersulfone, a polyester or a polyphosphate (polyphosphazene).

A separator 260 having a flow path 261 for fuel and air may be coupled to both sides of the membrane-electrode assembly to form a single unit cell. A gasket 250 may be provided between the membrane-electrode assembly and the separator 260 to maintain the sealing of the unit cell. Further, when the unit cell is sealed by using the gasket, the fuel electrode is improved in contact with the flow of the fuel, and the air electrode can improve the contact with the air flow. Although not shown in the drawing, both ends of the flow channel of the separation plate on which the flow path 261 is formed may be connected to an inlet or an outlet so that fuel and gas can flow into the flow channel. In addition, by stacking a plurality of such unit cells repeatedly, a stack structure (multilayer stack) can be formed.

Example

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. It should be understood, however, that these examples are provided for illustration only and are not intended to limit the scope of the present invention.

Manufacturing example  1: Fabrication of gold nanocore and Au / C

Add 10 g of distilled water to 1 g HAuCl ₄ (49 wt%) and dissolve to prepare Au ^{3 +} stock solution. Dissolve 0.3 g of trisodium citrate (Na ₃ C ₆ H ₅ O ₇ ) in 10 mL of distilled water. 0.0225 g of NaBH ₄ is dissolved in 30 mL of distilled water to prepare a NaBH ₄ solution. 1.9137 g of Au ^{3 +} stock solution and trisodium citrate solution are added to 2 L of distilled water and stirred vigorously. To the solution containing Au ^{3 +} and trisodium citrate, 1 mL of NaBH ₄ solution is added to reduce Au ³⁺ to form a gold nanoparticle. At this time, as the NaBH ₄ was added, the color of the Au ^{3 +} solution changed from yellow to sour red, red and bright red. The size of the gold nanoparticles thus produced was controlled by controlling the concentration of trisodium citrate solution, and the average particle size was confirmed by a transmission electron microscope (TEM).

The Au nanoparticle was prepared by adding 0.7818 g of Vulcan XC-72R to 150 mL of distilled water and pulverizing and dispersing in an ultrasonic generator for 30 minutes to prepare a gold nanoparticle solution. Vulcan XC-72R dispersed in a gold nanoparticle solution was added and stirred vigorously for 24 hours to prepare a carrier (Au / C (trade name)) carrying a gold nanoparticle on a Vulcan XC-72R ).

The support (Au / C) was filtered under reduced pressure, washed with distilled water and dried in an oven at 60 ° C. for 3 hours or more. The morphology of the resulting Au / C was confirmed by transmission electron microscopy and analyzed by TGA Au content was confirmed. As a result, the average size of the gold nanoparticles produced was 4.11 ± 1.48 nm and the Au content was 10 ± 1 wt% on average.

Also, the area of Au in the support (Au / C) produced by the cyclic voltammetry was confirmed. The area of Au was measured using a 0.5 M H ₂ SO ₄ solution as the electrolyte and the reduction peak size of Au oxide at 880 mV was used at a scan rate of 10 mV / s in a voltage range from -270 mV to 1,380 mV . As a result, the Au area of the support (Au / C) was 43,800 + 4,830 cm ² per 1 g of the support.

A transmission electron microscope photograph of the thus prepared Au / C support is shown in FIG.

Manufacturing example  2: Pt shell / Au NPs  on Vulcan XC -72R (Pt / Au / C) catalyst production

A Pt stock solution was prepared by dissolving 10 g of H ₂ PtCl ₆ (98.5%) reagent in 0.5 MH ₂ SO ₄ to obtain a total volume of 100 mL. At this time, the concentration of Pt stock solution is 0.19 M, and this solution is diluted with 0.5 MH ₂ SO ₄ solution to the desired concentration. 1 g of the support (Au / C) prepared in Preparation Example 1 was placed in 40 mL vial, 20 mL of H ₂ PtCl ₆ solution was added, and Pt was irreversibly adsorbed on Au surface of Au / C while stirring for 3 hours. Thereafter, washing with 10 mL of 0.5 MH ₂ SO ₄ solution was repeated 10 times to remove residual Pt ⁴⁺ . Then, 0.0150 g of NaBH ₄ dissolved in 20 mL of distilled water was added to the vial containing the washed Pt / Au / C and stirred for 30 minutes to reduce the adsorbed Pt ^{4 +} to Pt metal, Washed and dried at 60 캜 for 3 hours or more.

Example  One : Bi -Pt shell / Au NPs  on Vulcan XC -72R ( Bi -Pt / Au / C) catalyst production

Bismuth solution was prepared by dissolving Bi ₂ O ₃ (99.999%) in 0.5 MH ₂ SO ₄ solution to give a Bi ^{3 +} ion concentration of 0.5 mM and 2 mM. To prepare a 2 mM Bi ^{3 +} solution, 0.0466 g of Bi ₂ O ₃ reagent was placed in a 100 mL volumetric flast, filled with 0.5 MH ₂ SO ₄ solution up to the bar, and then used after Bi ₂ O ₃ was completely dissolved. 0.05 g of the Pt (shell) Au / C catalyst (Pt / Au / C) prepared in Preparation Example 2 and 10 mL of the Bi ₂ O ₃ solution prepared above were placed in a 40 mL vial and stirred for 24 hours to obtain Pt / Au / C Bi ^{3 +} was irreversibly adsorbed on the Pt surface. Thereafter, washing with 5 mL of distilled water was repeated 5 times to remove residual Bi ^{3 +} ions, and the amount of Bi adsorbed to the concentration of irreversibly adsorbed Bi ^{3 +} solution was controlled. In addition, 0.0075 g of NaBH ⁴ dissolved in 10 mL of distilled water was added to the vial containing the washed catalyst and stirred for 30 minutes to reduce the adsorbed Bi ³⁺ . The solution was then filtered under reduced pressure, washed with distilled water, Hr to produce an oxidation catalyst for a fuel cell of Example 1.

Example  2: Bi / Membrane-electrode assembly (MEA) fabrication using Pt / Au / C catalyst

About 88.3 mg of the Bi / Pt / Au / C catalyst prepared in Example 1 was added to a 15 ml vial, and 883 μl of tertiary distilled water was added thereto, followed by mixing and crushing on a sonicator for 1 minute. To this, 88.3 mg of ion solution (5% Nafion solution) was added and sonication was repeated. Approximately 5.3 g of 2-propanol was added and sonication was conducted for 30 minutes or longer to prepare a catalyst ink. The catalyst ink prepared as described above was uniformly sprayed onto carbon paper using a spray gun, and a proper amount of Pt catalyst was controlled to be loaded. In the case of the cathode, 0.5 mg / cm ² of Pt was loaded so that 3.0 mg / cm ² was loaded using Pt black as a catalyst and 0.5 mg / cm ² of Pt was loaded, respectively. The carbon paper used had an active area of 5.06 cm ² , hydrophobic carbon paper treated with 5% Teflon for the air electrode, and carbon paper not subjected to hydrophobic treatment for the fuel electrode.

The membrane-electrode assembly (MEA) was prepared by placing the polymer electrolyte membrane between the air electrode coated with each catalyst ink and the anode and compressing the polymer electrolyte membrane at 140 ° C. and 1.5 MPa for 5 minutes under hot press to prepare a membrane- And separator plates having fuel and air flow paths formed on both sides thereof were assembled to assemble the unit cells.

The assembled unit cell was connected to an electrochemical performance evaluation system, and a heater and a humidifier were operated to maintain the temperature and the humidity. First, distilled water was injected and the MEA was wetted for 1 to 1.5 hours, and 0.5 to 1 M of methanol was injected to confirm that the open circuit voltage (OCV) was stable, and the current-voltage (I-V) was measured. After the I-V measurement, the membrane was washed with distilled water. When the OCV was dropped, washing was completed, and the membrane was allowed to stand overnight to sufficiently activate the anode and the cathode of the MEA and the membrane.

Comparative Example  Preparation of membrane-electrode assembly (MEA) using Pt / C catalyst

Approximately 83.6 mg of 10 wt% Pt / C commercial catalyst was added to a 15 ml vial and 835 μl of tertiary distilled water was added, followed by mixing and grinding on a sonicator for 1 minute. To this, 83.6 mg of ion solution (5% Nafion solution) was added and sonication was repeated. Approximately 5 g of 2-propanol was added and sonication was conducted for 30 minutes or longer to prepare a catalyst ink. The catalyst ink prepared above was uniformly sprayed on carbon paper using a spray gun so that a proper amount of Pt catalyst was loaded. In the case of the cathode, 0.5 mg / cm ² of Pt was loaded so that 3.0 mg / cm ² was loaded using Pt black as a catalyst and 0.5 mg / cm ² of Pt was loaded, respectively. The carbon paper used had an active area of 5.06 cm ² , hydrophobic carbon paper treated with 5% Teflon for the air electrode, and carbon paper not subjected to hydrophobic treatment for the fuel electrode.

The membrane-electrode assembly (MEA) was prepared by placing the polymer electrolyte membrane between the air electrode coated with each catalyst ink and the anode and compressing the polymer electrolyte membrane at 140 ° C. and 1.5 MPa for 5 minutes under hot press to prepare a membrane- And separator plates having fuel and air flow paths formed on both sides thereof were assembled to assemble the unit cells.

The assembled unit cell was connected to an electrochemical performance evaluation system, and a heater and a humidifier were operated to maintain the temperature and the humidity. First, distilled water was injected and the MEA was wetted for 1 to 1.5 hours, and 0.5 to 1 M of methanol was injected to confirm that the open circuit voltage (OCV) was stable, and the current-voltage (I-V) was measured. After the I-V measurement, the membrane was washed with distilled water. When the OCV was dropped, washing was completed, and the membrane was allowed to stand overnight to sufficiently activate the anode and the cathode of the MEA and the membrane.

Comparative Example  2: Preparation of membrane-electrode assembly (MEA) using Pt / Au / C catalyst

About 88.3 mg of the Pt / Au / C catalyst prepared in Preparation Example 2 was added to a 15 ml vial, and 883 μl of tertiary distilled water was added thereto, followed by mixing and pulverizing on a sonicator for 1 minute. To this, 88.3 mg of ion solution (5% Nafion solution) was added and sonication was repeated. Approximately 5.3 g of 2-propanol was added and sonication was conducted for 30 minutes or longer to prepare a catalyst ink. The catalyst ink prepared as described above was uniformly sprayed onto carbon paper using a spray gun, and a proper amount of Pt catalyst was controlled to be loaded. In the case of the cathode, 0.5 mg / cm ² of Pt was loaded so that 3.0 mg / cm ² was loaded using Pt black as a catalyst and 0.5 mg / cm ² of Pt was loaded, respectively. The carbon paper used had an active area of 5.06 cm ² , hydrophobic carbon paper treated with 5% Teflon for the air electrode, and carbon paper not subjected to hydrophobic treatment for the fuel electrode.

The membrane-electrode assembly (MEA) was prepared by placing the polymer electrolyte membrane between the air electrode coated with each catalyst ink and the anode and compressing the polymer electrolyte membrane at 140 ° C. and 1.5 MPa for 5 minutes under hot press to prepare a membrane- And separator plates having fuel and air flow paths formed on both sides thereof were assembled to assemble the unit cells.

The assembled unit cell was connected to an electrochemical performance evaluation system, and a heater and a humidifier were operated to maintain the temperature and the humidity. First, distilled water was injected and the MEA was wetted for 1 to 1.5 hours, and 0.5 to 1 M of methanol was injected to confirm that the open circuit voltage (OCV) was stable, and the current-voltage (I-V) was measured. After the I-V measurement, the membrane was washed with distilled water. When the OCV was dropped, washing was completed, and the membrane was allowed to stand overnight to sufficiently activate the anode and the cathode of the MEA and the membrane.

≪ Evaluation of unit cell performance >

The unit cells prepared in Example 2 and Comparative Example 1 were evaluated for unit cell performance under an air supply condition of 500 ml / min. The results are shown graphically in FIG.

(Performance evaluation condition)

Fuel electrode: 6M formic acid, 60 占 폚, 5 ml / min, air electrode: 500 ml / min air

(Performance evaluation result)

Comparative Example 1: Pmax = 50 mW / cm ² at 211 mA / cm ² , OCV = 0.711 V, Pt / C (10 wt%

Example 2: Pmax = 70 mW / cm 2 at 217 mA / cm 2, OCV = 0.795 V

As can be seen from FIG. 5, the maximum power density (70 mW / cm ² ) of the unit cell of Example 2 using the catalyst of Example 1 (Bi / Pt / Au / C oxidation catalyst) catalyst showed 20 mW / cm ² higher than the 50 mW / cm ^2, the maximum power density (Pt / C (10wt%) commercial catalyst), which is the unit cell of the present invention in example 2 to be further enhanced 40% And the performance is excellent.

While the present invention has been described in connection with what is presently considered to be fictitious by those skilled in the art, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. It will be understood that various modifications and changes may be made in the present invention. Accordingly, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

10: Carbon-based carrier
11: Gold nanoparticles
12: Platinum
13: Oxidation rate promoting element
230: Polymer electrolyte membrane
220: anode catalyst layer
210: anode electrode support
260: separator plate
261: Fuel flow
300: single cell

Claims (17)

Carbon based carrier;
A gold (Au) nanocore supported on the carbon-based support; And
A platinum (Pt) and an oxidation-rate promoting element irreversibly adsorbed on the gold nanocore; Wherein the oxidation catalyst for a fuel cell comprises:
The method according to claim 1,
Wherein the carbon-based support comprises at least one of carbon black, activated carbon, carbon nanotube, carbon fiber, fullerene and graphene.
The method according to claim 1,
Wherein the gold (Au) nanocore has an average particle diameter of 1 nm to 100 nm.
The method according to claim 1,
Wherein the content of the irreversibly adsorbed platinum (Pt) is 0.04 wt% to 60 wt% of the oxidation catalyst for a fuel cell.
The method according to claim 1,
Wherein the shell is a single-layered shell in which platinum and an oxidation rate promoting element are irreversibly co-adsorbed on the gold nanocore, and the oxidation rate promoting element is selected from the group consisting of ruthenium (Ru), copper (Cu), silver (Ag), germanium ) Containing at least one element selected from the group consisting of tin (Sn), lead (Pb), arsenic (As), antimony (Sb), bismuth (Bi), selenium (Se) Oxidation catalyst for batteries.
The method according to claim 1,
Wherein the shell has a multi-layered shell structure, an inner shell on which the platinum is irreversibly adsorbed on the gold nanocore, and an outer shell on which the oxidation rate promoting element is irreversibly adsorbed, and the oxidation rate promoting element is ruthenium Ru, Cu, Ag, Ge, Sn, Pb, As, Sb, Bi, (Te). ≪ / RTI >

A carrier preparation step of supporting the gold nanocore on the carbon carrier; And
And irreversibly adsorbing platinum (Pt) on the gold nanocore to form a shell,
The shell manufacturing step comprises irreversibly co-adsorbing platinum and an oxidation rate promoting element on the gold nanocore to produce a single-layered shell; Or irreversibly adsorbing platinum on the gold nanocore to form an inner shell and irreversibly adsorbing an oxidation rate promoting element on the inner shell to form an outer shell to produce a multilayer shell, Gt;
8. The method of claim 7,
The method for manufacturing a support for a fuel cell according to claim 1, wherein the carrier is manufactured by preparing a gold (Au) nanocore having an average particle size of 1 nm to 100 nm, and then carrying and supporting the carbon carrier and the gold (Au) nanocore.
8. The method of claim 7,
Wherein the carbon-based carrier comprises at least one of carbon black, activated carbon, carbon nanotube, carbon fiber, fullerene and graphene.
8. The method of claim 7,
Wherein the content of the platinum (Pt) is 0.04 wt% to 60 wt% of the oxidation catalyst for a fuel cell.
8. The method of claim 7,
The oxidation rate promoting element may be at least one selected from the group consisting of Ru, Cu, Ag, Ge, Sn, Pb, As, Sb, Bi, , Selenium (Se), and tellurium (Te).
8. The method of claim 7,
The preparation of the single-layered shell is carried out by stirring the support, the platinum ion solution and the ionic solution of the oxidation-rate-promoting element with stirring, and cations of the platinum cation and the oxidation-rate promoting element are irreversibly adsorbed on the metallic nanocore and then reduced Wherein the oxidizing catalyst is a catalyst.
8. The method of claim 7,
The multi-layered shell is produced by stirring the platinum ion solution with the carrier to form an inner shell irreversibly adsorbed on the metal nanocore by the platinum cation, and adsorbing the cation of the oxidation promoting element and the support on which the inner shell is formed And agitating to form an outer shell in which cations of the oxidation rate promoting element are irreversibly adsorbed.
The fuel cell according to any one of claims 1 to 6, wherein the oxidation catalyst for fuel cell comprises a fuel electrode coated on a support, a polymer electrolyte membrane bonded on one side to the fuel electrode, and an air electrode bonded on the other side of the polymer electrolyte membrane.
15. The method of claim 14,
The polymer electrolyte membrane may be formed of a polymer selected from the group consisting of a hydrocarbon-based polymer, a polyimide, a perfluorosulfonic acid polymer, a polysulfone, a polyether sulfone, a polyester, or a polyphosphazene. And at least one fuel cell.
15. The method of claim 14,
The anode may be formed by coating a catalyst ink containing the oxidation catalyst for a fuel cell on a support (Catalyst Coated Substrate (CCS)), and the coating method may be selected from electroplating, spraying, painting, doctor blade, Wherein the fuel cell comprises at least one fuel cell.
15. The method of claim 14,
The fuel cell includes at least one of a hydrogen fuel cell, a methanol direct liquid fuel cell, an ethanol direct liquid fuel cell, a formic acid direct liquid fuel cell, and a dimethyl ether (DME) direct liquid fuel cell.

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