KR102416425B1 - Method for producing a platinum-based alloy catalyst for fuel cell containing cobalt - Google Patents

Abstract

The present invention relates to a method for manufacturing a method for manufacturing a platinum-based alloy catalyst for a fuel cell containing cobalt, and is intended to simplify the manufacturing process by omitting the process of preparing a cobalt precursor solution. The present invention comprises the steps of dispersing a carbon-based catalyst support in a polyol to prepare a carbon-based catalyst support solution; preparing a mixed solution by adding a platinum solution and a cobalt precursor powder to a carbon-based catalyst carrier solution and mixing at 40 to 100° C.; adding a pH adjusting agent to the mixed solution; applying a temperature to the mixed solution to which the pH adjusting agent is added to reduce it to a platinum-based alloy containing cobalt and supporting it on a carbon-based catalyst carrier; and washing and drying the mixed solution containing the platinum-based alloy supported on the carbon-based catalyst carrier; provides a method for producing a platinum-based alloy catalyst for fuel cells containing cobalt.

Description

Method for producing a platinum-based alloy catalyst for fuel cell containing cobalt

The present invention relates to a method for producing a platinum-based alloy catalyst, and more particularly, to a method for producing a platinum-based alloy catalyst for a fuel cell containing cobalt, in which a cobalt precursor powder is directly used for catalyst synthesis.

A fuel cell is a device that converts chemical energy into electrical energy through an electrochemical reaction by supplying gas or liquid fuel from the outside, rather than having reactants and products inside the cell like normal cells (primary and secondary). to be. Fuel cells are highly efficient, eco-friendly, and use a variety of fuels. Fuel cells have the advantage that they can be manufactured for various industrial fields depending on the type. Because of these advantages, fuel cells can be applied to various industries, from portable power sources such as portable devices, to transportation power sources for automobiles, and distributed power sources available for home and power plant business.

There are various types of such fuel cells according to the types of fuels and electrolytes used. For example, the fuel cell, depending on the type of fuel, a polymer electrolyte fuel cell (PEMFC), a direct methanol fuel cell (DMFC), a phosphoric acid fuel cell (Phosphoric Acid Fuel Cell: PAFC), solid oxide fuel cell (SOFC), alkaline electrolyte fuel cell (AFC), and the like.

Since the efficiency of such a fuel cell is greatly affected by the rate of electrode reaction, a nano-sized catalyst is used as an electrode material. Electrode catalysts used in fuel cells have a disadvantage in that their manufacturing cost is high because platinum (Pt)-based noble metals have been the mainstream until now. As described above, the conventional fuel cell using the platinum-based electrode catalyst has no choice but to increase the economic burden, and the commercialization stage is delayed due to the limited reserves and the use of very expensive platinum. Moreover, it has been reported that in order for fuel cell vehicles to be commercialized, the amount of platinum used per kW should be reduced to 0.2 g or less.

In order to solve this problem, research on non-platinum-based catalysts is being actively conducted. However, it is true that it is difficult to apply the non-platinum-based catalyst to an electrode for an actual fuel cell.

Therefore, apart from the development of the above-described non-platinum catalyst material, research and development of platinum-based alloy catalyst materials with reduced platinum usage are being actively conducted, and these platinum-based alloy catalyst materials use a small amount of platinum compared to pure platinum materials. It is possible to manufacture a high-performance catalytic electrode with improved catalytic activity while still doing so. For example, Korean Patent Publication No. 10-1340984 discloses a method for producing a platinum-based alloy catalyst. According to the disclosed method for producing a platinum-based alloy catalyst, a transition metal is first supported on a carbon-based catalyst carrier, and platinum is sequentially supported by preparing according to a liquid phase reduction method, thereby controlling the particle size of the transition metal, and then the size of the platinum nanoparticles can be controlled and supported, and a platinum alloy catalyst with reduced amount of platinum can be prepared while increasing the activity of the catalyst.

However, when the transition metal is supported on the carbon-based catalyst carrier, the transition metal precursor is mixed with a solvent to prepare a transition metal precursor solution, and after preparing the carbon-based catalyst carrier solution, the transition metal precursor solution and the carbon-based catalyst carrier solution are mixed. Use the mixing method.

For this reason, it is necessary to separately prepare a transition metal precursor solution by calculating the transition metal precursor in a volume ratio and mixing it with a solvent. And since it is mixed with the carbon-based catalyst carrier solution in the form of a transition metal precursor solution, there is a limit in accurately controlling the amount of the transition metal precursor supported on the carbon-based catalyst carrier.

Registered Patent Publication No. 10-1340984 (2013.12.12. Announcement)

Accordingly, an object of the present invention is to provide a method for manufacturing a platinum-based alloy catalyst for fuel cells containing cobalt, which can simplify the manufacturing process by omitting the process of preparing a cobalt precursor solution.

Another object of the present invention is to provide a method for preparing a platinum-based alloy catalyst for a fuel cell containing cobalt, which can more easily and precisely control the amount of a cobalt precursor supported on a carbon-based catalyst carrier.

In order to achieve the above object, the present invention comprises the steps of dispersing a carbon-based catalyst support in a polyol to prepare a carbon-based catalyst support solution; preparing a mixed solution by adding a platinum solution and a cobalt precursor powder to the carbon-based catalyst carrier solution and mixing at 40 to 100° C.; adding a pH adjusting agent to the mixed solution; reducing the platinum-based alloy containing cobalt by applying a temperature to the mixed solution to which the pH adjusting agent is added, and supporting it on the carbon-based catalyst carrier; and washing and drying the mixed solution containing the platinum-based alloy supported on the carbon-based catalyst carrier; provides a method for producing a platinum-based alloy catalyst for fuel cells containing cobalt.

The polyol is at least one selected from the group consisting of ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), tetraethylene glycol (TTEG), propylene glycol (PG) and butylene glycol (BG). may include

The carbon-based catalyst carrier may include at least one selected from the group consisting of activated carbon, carbon black, Ketjen black, carbon nanotubes, carbon nanofibers, graphite, graphene, and graphene oxide.

The cobalt precursor is at least one selected from the group consisting of cobalt chloride, cobalt acetylacetonate, cobalt carbonyl, cobalt oxalate and cobalt nitrate. may include

The reducing agent may include at least one selected from the group consisting of sodium hydroxide, sodium borohydride, hydrazine and formaldehyde.

In the supporting step, the mixture solution to which the pH adjusting agent is added is maintained at 130 to 180° C. for 2 to 7 hours to reduce it to a platinum-based alloy containing cobalt, and may be supported on the carbon-based catalyst carrier.

In the step of preparing the mixed solution, the volume ratio of the carbon-based catalyst carrier solution, the platinum solution, and the cobalt precursor powder may be 40 to 80: 20 to 60: 3 to 10.

The platinum-based alloy catalyst prepared in the washing and drying step includes the carbon-based catalyst support and a platinum-based alloy supported on the carbon-based catalyst support.

The platinum-based alloy may include 90 to 97 wt% of platinum and 3 to 10 wt% of cobalt.

The washing and drying may include: filtering the platinum-based alloy catalyst from the mixed solution; washing the filtered platinum-based alloy catalyst with ethanol and deionized water; and vacuum drying the washed platinum-based alloy catalyst.

And the present invention, dispersing the carbon-based catalyst carrier in ethylene glycol (EG) to prepare a carbon-based catalyst carrier solution; preparing a mixed solution by adding a platinum solution and a cobalt precursor powder to the carbon-based catalyst carrier solution and mixing at 40 to 100° C.; adjusting the pH to 9-12 by adding 0.1 to 1M NaOH to the mixed solution; maintaining the NaOH-added mixture at 130 to 180° C. for 2 to 7 hours to reduce it to a platinum-based alloy containing cobalt and supporting it on the carbon-based catalyst carrier; and filtering, washing and drying the mixture containing the platinum-based alloy supported on the carbon-based catalyst carrier to obtain a platinum-based alloy catalyst; providing a method for producing a platinum-based alloy catalyst for fuel cells containing cobalt, comprising: do.

According to the present invention, since the platinum-based alloy catalyst for a fuel cell is manufactured by directly injecting the cobalt precursor powder into the carbon-based catalyst carrier solution, the manufacturing process can be simplified by omitting the existing process of preparing the cobalt precursor solution. At this time, the cobalt precursor powder is directly injected into the carbon-based catalyst carrier solution to prepare a mixed solution, and then the temperature of the mixed solution is maintained at 130 to 180 ° C. can hold

And since the cobalt precursor powder is directly injected into the carbon-based catalyst carrier solution, the amount of cobalt particles supported on the carbon-based catalyst carrier can be more easily and accurately adjusted.

1 is a flowchart according to a method of manufacturing a platinum-based alloy catalyst for a fuel cell using the transition metal precursor powder according to the present invention directly for catalyst synthesis.
FIG. 2 is a table showing TEM images and EDX analysis results of a platinum-based alloy catalyst for a fuel cell containing nickel prepared according to Example 1. FIG.
3 is a table showing a TEM photograph and an EDX analysis result of a platinum-based alloy catalyst for a fuel cell prepared according to Comparative Example 1. Referring to FIG.
4 is a table showing a TEM photograph and an EDX analysis result of a platinum-based alloy catalyst for a fuel cell containing cobalt prepared according to Example 2.

It should be noted that, in the following description, only parts necessary for understanding the embodiments of the present invention will be described, and descriptions of other parts will be omitted without departing from the gist of the present invention.

The terms or words used in the present specification and claims described below should not be construed as being limited to their ordinary or dictionary meanings, and the inventors have appropriate concepts of terms to describe their invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined in Accordingly, the embodiments described in this specification and the configurations shown in the drawings are only preferred embodiments of the present invention, and do not represent all of the technical spirit of the present invention, so various equivalents that can be substituted for them at the time of the present application It should be understood that there may be variations and variations.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a flowchart according to a method of manufacturing a platinum-based alloy catalyst for a fuel cell using the transition metal precursor powder according to the present invention directly for catalyst synthesis.

1, the method for preparing a platinum-based alloy catalyst for a fuel cell (hereinafter referred to as 'platinum-based alloy catalyst') according to the present invention comprises the steps of dispersing a carbon-based catalyst carrier in a polyol to prepare a carbon-based catalyst carrier solution ( S10), adding a platinum solution and a transition metal precursor powder to a carbon-based catalyst carrier solution and mixing at 40 to 100° C. to prepare a mixed solution (S20), adding a pH adjuster to the mixed solution (S30), pH control A step (S40) of reducing the platinum-based alloy containing the transition metal to a platinum-based alloy containing a transition metal by applying a temperature to the mixture solution to which the agent is added, and supporting it on a carbon-based catalyst support (S40), and washing and washing the mixture containing the platinum-based alloy supported on the carbon-based catalyst support and drying (S50).

Each step according to the method for producing the platinum-based alloy catalyst according to the present invention will be described in detail as follows.

First, a carbon-based catalyst carrier solution is prepared by dispersing the carbon-based catalyst carrier in a polyol in step S10.

Here, the carbon-based catalyst carrier may include at least one selected from the group consisting of activated carbon, carbon black, Ketjen black, carbon nanotubes, carbon nanofibers, graphite, graphene, and graphene oxide.

The polyol contains at least one selected from the group consisting of ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), tetraethylene glycol (TTEG), propylene glycol (PG), and butylene glycol (BG) can do.

The carbon-based catalyst carrier solution includes 40 to 80% by weight of the carbon-based catalyst carrier and 20 to 60% by weight of a polyol.

Next, in step S20, the platinum solution and the transition metal precursor powder are added to the carbon-based catalyst carrier solution, and then mixed at 40 to 100° C. to prepare a mixed solution.

Here, the mixed solution may be prepared by mixing a carbon-based catalyst carrier solution, a platinum solution, and a transition metal precursor powder at a synthesis ratio (volume ratio) of 40 to 80: 20 to 60: 3 to 10.

The platinum solution may contain 5 to 20% by weight of platinum.

The transition metal precursor may include at least one selected from the group consisting of a nickel precursor, a cobalt precursor, a palladium precursor, a ruthenium precursor, a copper precursor, an iridium precursor, and an iron precursor.

Here, as a nickel precursor, nickel acetate, Ni(acac) ₂ , nickel chloride (NiCl ₂ ), nickel nitrate (Ni(NO ₃ ) ₂ ), nickel chloride hydrate (NiCl ₂ oxH ₂ O), nickel nitrate hydrate ( Ni(NO ₃ ) ₂ oxH ₂ O), nickel sulfate (NiSO ₄ ), and nickel sulfate hydrate (NiSO ₄ oxH ₂ O) may include at least one selected from the group consisting of.

The cobalt precursor is at least one selected from the group consisting of cobalt chloride, cobalt acetylacetonate, cobalt carbonyl, cobalt oxalate and cobalt nitrate. may include

Conventionally, when preparing a mixed solution, a transition metal precursor powder was mixed in a separate solvent to prepare a transition metal precursor solution, and then a carbon-based catalyst carrier solution, a platinum solution, and a transition metal precursor solution were mixed.

On the other hand, in the present invention, since the mixture solution can be prepared by adding the transition metal precursor powder to the carbon-based catalyst carrier solution and the platinum solution, the manufacturing process can be simplified by omitting the process of preparing the existing transition metal precursor solution.

And so that the transition metal precursor powder can be well dissolved by being put into the carbon-based catalyst carrier solution and the platinum solution, it is preferable that step S20 be performed at 40 to 100°C. There may be a problem that the transition metal precursor powder is not well dissolved at 40° C. or less. Conversely, when it exceeds 100° C., side reactions other than mixing may occur between the transition metal precursor powder, the carbon-based catalyst carrier solution, and the platinum solution.

Next, a pH adjusting agent is added to the mixed solution in step S30. That is, the mixture is adjusted to pH 9-12 using a pH adjuster. By adjusting the pH of the mixed solution using a pH adjusting agent, the amount and particle size of the platinum-based alloy to be reduced can be controlled.

Here, the pH adjusting agent may include at least one selected from the group consisting of sodium hydroxide, sodium borohydride, hydrazine and formaldehyde. For example, 0.1M to 1M sodium hydroxide may be used as a pH adjuster.

Subsequently, in step S40, a temperature is applied to the mixed solution to which the pH adjuster is added to reduce it to a platinum-based alloy containing a transition metal and support it on a carbon-based catalyst carrier. That is, the mixture is maintained at 130 to 180° C. for 2 to 7 hours to reduce the transition metal precursor to transition metal nanoparticles. The reduced transition metal nanoparticles are synthesized with platinum to form a platinum-based alloy. And a platinum-based alloy is supported on the carbon-based catalyst carrier.

And by washing and drying the mixture containing the platinum-based alloy in step S50, it is possible to obtain a platinum-based alloy catalyst according to the present invention. That is, the platinum-based alloy catalyst is filtered from the mixed solution. The filtered platinum-based alloy catalyst is washed with ethanol and deionized water. And by vacuum-drying the washed platinum-based alloy catalyst, it is possible to obtain a platinum-based alloy catalyst according to the present invention. Drying may be performed at 60 to 100° C. for 6 hours to 24 hours.

As described above, the platinum-based alloy catalyst prepared by the manufacturing method according to the present invention includes a carbon-based catalyst support and a platinum-based alloy supported on the carbon-based catalyst support. Here, in the platinum-based alloy catalyst, the content of the transition metal can be controlled by controlling the synthesis ratio of the mixed solution in step S20 and the temperature applied to the mixed solution. The platinum-based alloy may include 67 to 97 wt% of platinum and 3 to 33 wt% of a transition metal. For example, when the transition metal is nickel, the platinum-based alloy may include 80 to 97% by weight of platinum and 3 to 20% by weight of nickel. When the transition metal is cobalt, the platinum-based alloy may include 90 to 97 wt% of platinum and 3 to 10 wt% of cobalt.

According to the present invention, since the platinum-based alloy catalyst is prepared by directly injecting the transition metal precursor powder into the carbon-based catalyst carrier solution, it is possible to simplify the manufacturing process by omitting the process of preparing the existing transition metal precursor solution. At this time, when the transition metal precursor powder is directly added to the carbon-based catalyst carrier solution and mixed, the temperature of the mixture is maintained at 130 to 180 ° C. can hold

And since the transition metal precursor powder is directly injected into the carbon-based catalyst carrier solution, the amount of the transition metal particles supported on the carbon-based catalyst carrier can be more easily and accurately adjusted.

[Examples and Comparative Examples]

With respect to the method for producing the platinum-based alloy catalyst according to the present invention, the content of the transition metal included in the platinum-based alloy catalyst was confirmed through Examples 1 and 2 and Comparative Examples. In Example 1, nickel was used as the transition metal, and in Example 2, cobalt was used as the transition metal.

[Example 1]

First, 50 wt% of carbon black was dispersed in ethylene glycol (EG) to prepare a carbon-based catalyst carrier solution. Next, a mixture of the carbon-based catalyst carrier solution, the platinum solution, and the nickel precursor powder was prepared in a synthesis ratio (volume ratio) of 50:45:5. The platinum solution contains 10% by weight platinum. Nickel acetate powder was used as the nickel precursor powder.

At this time, in Example 1, the mixture was mixed at 50 ° C. for 5 minutes, and in Comparative Example, the mixture was prepared by mixing at room temperature for 5 minutes.

Next, 1M NaOH is added to the mixture to adjust the pH to 11, and then a platinum-based alloy containing nickel, which is reduced by maintaining at 160° C. for 3 hours, is supported on a carbon-based catalyst carrier.

After filtering and washing the mixed solution containing the reduced platinum-based alloy, it was dried at 80° C. for 12 hours to prepare a platinum-based alloy catalyst according to Example 1 and Comparative Example.

In Example 2, a platinum-based alloy catalyst containing cobalt was prepared in the same manner as in Example 1, except that a cobalt precursor was used. Cobalt chloride was used as the cobalt precursor powder.

2 is a table showing the TEM photograph and EDX analysis results of the platinum-based alloy catalyst prepared according to Example 1. And Figure 3 is a table showing the TEM photograph and EDX analysis results of the platinum-based alloy catalyst prepared according to Comparative Example. Here, the composition ratio of the platinum-based alloy supported on the carbon-based catalyst carrier is shown in FIGS. 2 and 3 . That is, the composition ratio of the platinum-based alloy excluding the carbon-based catalyst carrier in the platinum-based alloy catalyst is indicated.

2 and 3, the platinum-based alloy of the platinum-based alloy catalyst according to Comparative Example contains 0.08 wt% of nickel, but the platinum-based alloy of the platinum-based alloy catalyst according to Example 1 contains 10.90 wt% of nickel do. That is, after preparing the mixed solution by directly injecting the nickel precursor powder into the carbon-based catalyst carrier solution, the temperature of the mixed solution is maintained at 160 ° C. can

[Example 2]

4 is a table showing the TEM photograph and EDX analysis results of the platinum-based alloy catalyst containing cobalt prepared according to Example 2.

Referring to FIG. 4 , the platinum-based alloy of the platinum-based alloy catalyst according to Example 2 includes 4.33 wt% of cobalt. That is, after preparing the mixed solution by directly injecting the cobalt precursor powder into the carbon-based catalyst carrier solution, the temperature of the mixed solution is maintained at 160 ° C. can

On the other hand, the embodiments disclosed in the present specification and drawings are merely presented as specific examples to aid understanding, and are not intended to limit the scope of the present invention. It is apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

Claims (10)

preparing a carbon-based catalyst carrier solution by dispersing the carbon-based catalyst carrier in a polyol;
preparing a mixed solution by adding a platinum solution and a cobalt precursor powder to the carbon-based catalyst carrier solution and mixing at 40 to 100° C.;
adjusting the pH to 9-12 by adding a pH adjusting agent to the mixed solution;
maintaining the mixture solution to which the pH adjuster is added at 130 to 180° C. for 2 to 7 hours to reduce it to a platinum-based alloy containing cobalt and supporting it on the carbon-based catalyst carrier; and
washing and drying the mixed solution containing the platinum-based alloy supported on the carbon-based catalyst carrier;
A method for producing a platinum-based alloy catalyst for fuel cells containing cobalt, comprising a. According to claim 1,
The polyol is at least one selected from the group consisting of ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), tetraethylene glycol (TTEG), propylene glycol (PG) and butylene glycol (BG). A method for producing a platinum-based alloy catalyst for fuel cells containing cobalt, comprising: According to claim 1,
The carbon-based catalyst carrier is for a fuel cell containing cobalt, characterized in that it comprises at least one selected from the group consisting of activated carbon, carbon black, Ketjen black, carbon nanotubes, carbon nanofibers, graphite, graphene and graphene oxide A method for producing a platinum-based alloy catalyst. According to claim 1,
The cobalt precursor is at least one selected from the group consisting of cobalt chloride, cobalt acetylacetonate, cobalt carbonyl, cobalt oxalate and cobalt nitrate. A method for producing a platinum-based alloy catalyst containing cobalt, comprising: According to claim 1,
The method for producing a platinum-based alloy catalyst for fuel cells containing cobalt, characterized in that the pH adjusting agent comprises at least one selected from the group consisting of sodium hydroxide, sodium borohydride, hydrazine and formaldehyde. delete According to claim 1, In the step of preparing the mixture,
The volume ratio of the carbon-based catalyst carrier solution, the platinum solution and the cobalt precursor powder is 40-80: 20-60: 3-10. According to claim 1, wherein the platinum-based alloy catalyst prepared in the washing and drying step,
and a platinum-based alloy supported on the carbon-based catalyst support and the carbon-based catalyst support,
The platinum-based alloy is a method for producing a platinum-based alloy catalyst containing cobalt, characterized in that it comprises 90 to 97% by weight of platinum and 3 to 10% by weight of cobalt. According to claim 8, wherein the washing and drying step,
filtering the platinum-based alloy catalyst from the mixed solution;
washing the filtered platinum-based alloy catalyst with ethanol and deionized water; and
vacuum drying the washed platinum-based alloy catalyst;
A method for producing a platinum-based alloy catalyst for fuel cells containing cobalt, comprising: Dispersing the carbon-based catalyst carrier in ethylene glycol (EG) to prepare a carbon-based catalyst carrier solution;
preparing a mixed solution by adding a platinum solution and a cobalt precursor powder to the carbon-based catalyst carrier solution and mixing at 40 to 100° C.;
adjusting the pH to 9-12 by adding 0.1 to 1M NaOH to the mixed solution;
maintaining the NaOH-added mixture at 130 to 180° C. for 2 to 7 hours to reduce it to a platinum-based alloy containing cobalt and supporting it on the carbon-based catalyst carrier; and
obtaining a platinum-based alloy catalyst by washing and drying the mixed solution containing the platinum-based alloy supported on the carbon-based catalyst carrier;
A method for producing a platinum-based alloy catalyst for fuel cells containing cobalt, comprising a.

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