JP5761014B2 - Method for producing fuel cell catalyst - Google Patents

Description

  The present invention relates to a method for producing a catalyst layer used in a fuel cell.

  2. Description of the Related Art There is known a fuel cell including a membrane electrode assembly (also referred to as a MEA) that is configured by sandwiching an electrolyte membrane between an anode and a cathode. The anode and cathode of such a fuel cell are provided with a catalyst layer. In this catalyst layer, a PFF (Proton Film flow) structure (registered trademark) in which the hydrophilic functional groups of the polymer electrolyte are oriented on the catalyst side has been proposed (see Patent Document 1). In addition, in order to further stabilize the PFF structure in the catalyst layer, a configuration in which the surface of the catalyst in the catalyst layer is modified with an acidic functional group (for example, nitric acid group) has been proposed (see Patent Document 2). In this technique, a catalyst is added to a complex solution (platinum compound solution) and stirred, and then the stirred solution is filtered, and the filtrate (mixture of the complex solution and the catalyst) is dried to thereby make the catalyst acidic. It is modified with a group. The catalyst is a substance containing a carrier (for example, carbon) on which catalytic metal particles (for example, platinum) are supported.

JP 2006-140061 A JP 2011-228268 A

  However, in the technique of Patent Document 2 described above, when the stirred solution is filtered, it is difficult to control the amount of acidic functional groups in the filtrate. Therefore, the amount of the complex solution remaining in the filtrate cannot be controlled, and as a result, it is difficult to control the amount of the acidic functional group that modifies the catalyst.

  An object of this invention is to provide the technique which can control the quantity of the acidic functional group which modifies the catalyst of the catalyst layer for fuel cells.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.
[Mode 1] A method for producing a catalyst for a fuel cell, comprising:
A first mixed solution preparing step of preparing a first mixed solution including a catalyst including a carrier on which catalytic metal particles are supported, a solution of a platinum compound including an acidic functional group, and water;
Said water is evaporated from the first mixture preparing step wherein the first mixture is prepared by, and the catalyst, and the acidic functional groups contained in the platinum compound, and a mixture generating step of generating a mixture including at least ,
A heat treatment step of heat treating the mixture produced in the mixture production step, the heat treatment step having at least an action of fixing the acidic functional group to the catalyst;
With
After the first mixed solution preparation step and before the mixture generating step, the catalyst in the first mixed solution is collected in a part of the first mixed solution, and the supernatant of the first mixed solution is removed. Comprising the steps,
A method for producing a catalyst for a fuel cell.
[Mode 2] A method for producing a catalyst for a fuel cell, comprising:
A first mixed solution preparing step of preparing a first mixed solution including a catalyst including a carrier on which catalytic metal particles are supported, a solution of a platinum compound including an acidic functional group, and water;
Said water is evaporated from the first mixture preparing step wherein the first mixture is prepared by, and the catalyst, and the acidic functional groups contained in the platinum compound, and a mixture generating step of generating a mixture including at least ,
A heat treatment step of heat treating the mixture produced in the mixture production step, the heat treatment step having at least an action of fixing the acidic functional group to the catalyst;
With
After the first mixed solution preparation step and before the mixture generating step, the catalyst in the first mixed solution is collected in a part of the first mixed solution, and the supernatant of the first mixed solution is removed. Comprising the steps,
A method for producing a catalyst for a fuel cell.

[Application Example 1]
A method for producing a catalyst layer for a fuel cell, comprising:
A first mixed solution preparing step of preparing a first mixed solution including a catalyst including a carrier on which catalytic metal particles are supported, a platinum compound solution, and water;
A mixture generating step of evaporating water from the first mixed solution prepared in the first mixed solution preparing step to generate a mixture containing at least the catalyst and an acidic functional group;
A heat treatment step of heat treating the mixture produced in the mixture production step, the heat treatment step having at least an action of fixing the acidic functional group to the catalyst;
A method for producing a fuel cell catalyst layer.

  According to the said structure, the mixture produced | generated process which produces | generates the mixture which contains a catalyst and an acidic functional group at least by evaporating a water | moisture content from the 1st liquid mixture prepared at the 1st liquid mixture preparation process, and produced | generated the mixture. A heat treatment step having at least an action of fixing the acidic functional group to the catalyst is performed by heat-treating. In this way, compared to the case where the first mixed solution is filtered, the disappearance of ions that can be acidic functional groups in the first mixed solution can be suppressed, and many acidic functional groups generated from the ions can be suppressed. It can be used as an acidic functional group for modifying the catalyst. Therefore, for example, by adjusting the concentration of the platinum compound solution, the amount of the acidic functional group that modifies the catalyst can be controlled.

[Application Example 2]
A method for producing a fuel cell catalyst layer according to Application Example 1,
The first mixed liquid preparation step includes
A second mixed solution preparing step of preparing a second mixed solution containing the catalyst and the water;
After the second mixed liquid preparation step, a pulverization step of wet pulverizing the catalyst;
After the second mixed solution preparing step, a mixed solution adding step of adding the platinum compound solution to the second mixed solution to generate the first mixed solution;
A method for producing a fuel cell catalyst layer.

  According to the above configuration, since the catalyst is wet pulverized in the pulverization step, the catalyst in the first mixed solution can be finely divided. As a result, the surface area of the catalyst can be increased and the power generation efficiency of the fuel cell can be improved.

[Application Example 3]
A method for producing a fuel cell catalyst layer according to Application Example 2,
The first mixed liquid preparation step includes
After the second mixed solution preparation step, the first mixed solution, or a centrifugal stirring step of centrifugally stirring the second mixed solution,
Manufacturing method of catalyst layer for fuel cell.

  According to the above configuration, since the mixed liquid (the first mixed liquid or the second mixed liquid) is centrifugally stirred, fine bubbles in the mixed liquid can be removed.

[Application Example 4]
A method for producing a fuel cell catalyst layer according to any one of Application Examples 1 to 3,
After the first mixed solution preparation step and before the mixture generating step, the catalyst in the first mixed solution is collected in a part of the first mixed solution, and the supernatant of the first mixed solution is removed. Comprising the steps,
Manufacturing method of catalyst layer for fuel cell.

  According to the above configuration, the catalyst in the first mixed liquid is collected in a part of the first mixed liquid, and the supernatant liquid of the first mixed liquid is removed, so that moisture is evaporated from the first mixed liquid in the mixture generation step. In some cases, the amount of moisture evaporation can be reduced. As a result, the working time of the mixture generation process can be shortened.

[Application Example 5]
A method for producing a fuel cell catalyst layer according to any one of Application Examples 1 to 4,
The acidic functional group is any one of a nitric acid group, a nitrous acid group, a sulfonic acid group, a hydroxyl group, a carboxyl group, a carbonyl group, and a halogen group.
Manufacturing method of catalyst layer for fuel cell.

  The present invention can be realized in various forms. In addition to a method for manufacturing a fuel cell catalyst layer, for example, a method for manufacturing a fuel cell, a method for manufacturing a membrane electrode assembly, and the like. It can be realized in a manner. Further, it can be realized in the aspect of the invention of the device such as a fuel cell catalyst layer, a membrane electrode assembly, and a fuel cell.

It is a schematic sectional drawing of the fuel cell 100 manufactured with the manufacturing method of the fuel cell as one Example. It is a flowchart for demonstrating the manufacturing method of the fuel cell as 1st Example. It is a flowchart for demonstrating the manufacturing process of the pre paste in 1st Example. It is a figure which shows the functional block of the pre paste manufacturing apparatus 1000 in 1st Example. It is a schematic diagram which shows the state at the time of the stationary process in the manufacturing process of a pre paste, the time of a supernatant removal process, and the water | moisture-content evaporation process. It is a flowchart for demonstrating the manufacturing process of the pre paste of 2nd Example. It is a figure which shows the functional block of the pre paste manufacturing apparatus 2000 in 2nd Example. It is a flowchart for demonstrating the manufacturing process of the pre paste of 3rd Example. It is a figure which shows the functional block of the pre paste manufacturing apparatus 3000 in 3rd Example. It is a flowchart for demonstrating the manufacturing process of the pre paste of 4th Example. It is a figure which shows the functional block of the pre paste manufacturing apparatus 4000 in 4th Example.

  Next, embodiments of the present invention will be described based on examples with reference to FIGS.

A. First embodiment:
A1. Fuel cell configuration:
FIG. 1 is a schematic cross-sectional view of a fuel cell 100 manufactured by a method for manufacturing a fuel cell as one embodiment. As shown in FIG. 1, the fuel cell 100 includes an electrolyte membrane 10, a cathode side catalyst layer 20, an anode side catalyst layer 30, gas diffusion layers 40 and 50, and separators 60 and 70. The electrolyte membrane 10 is formed of a proton conductive polymer material, and for example, a fluorine resin such as Nafion (registered trademark of Dipton) or a hydrocarbon resin can be used. The cathode catalyst layer 20 is supplied with an oxidizing gas (for example, air (oxygen)), thereby causing an electrochemical reaction and generating water (H ₂ O). The anode-side catalyst layer 30 is supplied with a fuel gas (for example, hydrogen), thereby causing an electrochemical reaction and generating protons. Details of the configurations of the cathode side catalyst layer 20 and the anode side catalyst layer 30 will be described later. The gas diffusion layers 40 and 50 are formed of a material having conductivity and gas diffusibility, and for example, carbon paper, carbon cloth, carbon felt, metal mesh, expanded metal, and punching metal can be used. Water repellent treatment (for example, PTFE (polytetrafluoroethylene) processing) may be applied to the surface of the gas diffusion layers 40 and 50 opposite to the catalyst layer side. The separators 60 and 70 are formed of a gas-impermeable conductive member, and include a gas supply channel for supplying reaction gas (fuel gas, oxidizing gas) supplied from the outside to the gas diffusion layer. A fuel cell stack is configured by stacking a plurality of fuel cells 100.

A2. Manufacturing method of fuel cell:
FIG. 2 is a flowchart for explaining a method of manufacturing the fuel cell as the first embodiment. In the manufacturing method of the fuel cell 100 in the first embodiment, first, a pre-paste is manufactured (step S100). The pre-paste contains a catalyst and water. Details of the pre-paste manufacturing process will be described later.

  Subsequently, a polymer electrolyte and an alcohol (for example, ethanol) are prepared, and the pre-paste manufactured in step S100, the prepared polymer electrolyte, and the prepared alcohol are mixed to manufacture a catalyst paste (step S200). Specifically, a catalyst paste is manufactured by storing a mixed solution of a pre-paste, a polymer electrolyte, and alcohol in a rotation / revolution centrifugal stirrer and performing centrifugal stirring. As the rotation / revolution centrifugal agitator, for example, a hybrid mixer can be used.

  Next, a catalyst layer is manufactured using the catalyst paste manufactured in step 200 (step S300). Specifically, a catalyst paste is applied to the gas diffusion base material that forms the gas diffusion layer to form the catalyst layer on the gas diffusion base material. As this coating method, for example, screen printing, doctor blade method, spray coating method, or the like can be used. In this way, the cathode side catalyst layer 20 formed on the gas diffusion layer 40 and the anode side catalyst layer 30 formed on the gas diffusion layer 50 can be manufactured. Each catalyst layer includes a polymer electrolyte and a treated catalyst described later.

  Subsequently, the electrolyte membrane 10 is sandwiched between the cathode side catalyst layer 20 (gas diffusion layer 40) manufactured in step 300 and the anode side catalyst layer 30 (gas diffusion layer 50) manufactured in step 300. MEA is manufactured (step S400).

  Then, the MEA manufactured in step S400 is sandwiched between the separators 60 and 70 (step S500), and the fuel cell 100 is completed.

A3. Pre-paste manufacturing process:
FIG. 3 is a flowchart for explaining a pre-paste manufacturing process in the first embodiment. FIG. 4 is a diagram showing functional blocks of the pre-paste manufacturing apparatus 1000 for manufacturing the pre-paste in the first embodiment. FIG. 5 is a schematic diagram illustrating a state during a stationary process, a supernatant removing process, and a water evaporation process in the pre-paste manufacturing process. Specifically, FIG. 5 (a) shows the state during the standing step, (b) shows the state during the supernatant removal step, and (c) shows the state during the water evaporation step. is there.

  The pre-paste manufacturing apparatus 1000 includes a catalyst storage unit 1010, a water storage unit 1020, a platinum compound solution storage unit 1030, a stirring unit 1040, a supernatant removal unit 1050, an evaporation unit 1060, a drying unit 1070, and dry pulverization. A unit 1080 and a water amount adjustment unit 1090.

  In the pre-paste manufacturing process of the first embodiment, as shown in FIG. 3, first, in the process of step 110, the catalyst is placed in the catalyst housing portion 1010, the platinum compound solution is placed in the platinum compound solution housing portion 1030, and the water is water. Each is prepared in the accommodating part 1020.

  The catalyst includes a support on which catalytic metal particles are supported. As the catalyst metal particles, for example, platinum, palladium, ruthenium, cobalt, or an alloy containing these can be used. The carrier has a plurality of pores and is made of, for example, carbon, tin oxide, titanate compound, or the like. The carbon support is composed of, for example, acetylene black (for example, Denka black), ketjen black (for example, ketjen black EC600JD), Vulcan XC72, black pearl 2000, and diamond-like carbon (DLC).

A platinum compound solution is a solution containing a platinum compound. As such a platinum compound solution, platinum chloride (IV) acid hydrate aqueous solution (H ₂ PtCl ₆ .nH ₂ O / H ₂ O sol.), Platinum chloride (IV) hydrochloride acid solution (H ₂ PtCl ₆ / HCl sol.), Platinum chloride (IV) ammonium aqueous solution ((NH ₄ ) ₂ PtCl ₆ / H ₂ O sol.), Dinitrodiammine platinum (II) aqueous solution (cis- [Pt (NH ₃ ) ₂ (NO ₂ ) ₂ ] / H ₂ O sol.), Dinitrodiammine platinum (II) nitric acid solution (cis- [Pt (NH ₃ ) ₂ (NO ₂ ) ₂ ] / HNO ₃ sol.), Dinitrodiammine platinum (II) sulfuric acid solution ( cis- [Pt (NH ₃ ) ₂ (NO ₂ ) ₂ ] / H ₂ SO ₄ sol.), potassium tetracurl platinum (II) acid aqueous solution (K ₂ PtCl ₄ ) / H ₂ O sol. ), Platinum (II) chloride aqueous solution (PtCl ₂ / H ₂ O sol.), Aqueous platinum (IV) chloride (PtCl ₄ / H ₂ O sol.), Tetraammineplatinum (II) dichloride hydrate aqueous solution ([Pt (NH ₃ ) ₄ ] Cl ₂ .H ₂ O / H ₂ O sol.), Tetraammineplatinum (II) hydroxide aqueous solution ([Pt (NH ₃ ) ₄ ] (OH) ₂ / H ₂ O sol. .), Hexaammine platinum (IV) dichloride aqueous solution ([Pt (NH ₃ ) ₆ ] Cl ₂ / H ₂ O sol.), Hexaammine platinum (IV) hydroxide aqueous solution ([Pt (NH ₃ ) ₆ ] ( OH) ₂ / H ₂ O sol.), Hexahydroxoplatinum (IV) acid aqueous solution (H ₂ [Pt (OH) ₆ ] / H ₂ O sol.), Hexahydroxoplatinum (IV) acid nitric acid solution (H ₂ [ _{Pt (OH) 6] / HNO} 3 sol.), hexahydro Seo platinum (IV) acid sulfuric acid solution _{(H 2 [Pt (OH)} 6] / H 2 SO 4 sol.), Ethanolamine platinum solution _{(H 2 [Pt (OH)} 6] / H 2 NCH 2 CH 2 OH sol .) Etc. can be used. By using such a platinum compound solution, as an acidic functional group for modifying the catalyst in the water evaporation step of step S160 described later, a nitrate group, a nitrite group, a sulfonic acid group, a hydroxyl group, a carboxyl group, a carbonyl group, and Any one of halogen groups can be added.

According to the knowledge of the inventor, it is preferable to add a nitrate group as an acidic functional group for modifying the catalyst in the water evaporation step of step S160 described later. As a platinum compound solution therefor, among the above-described solutions, in particular, a dinitrodiammine platinum (II) nitric acid solution (cis- [Pt (NH ₃ ) ₂ (NO ₂ ) ₂ ] / HNO) having NO ₃ ⁻ as a hydrophilic ion. ₃ sol.), Hexahydroxoplatinum (IV) nitric acid solution ((H ₂ Pt (OH) ₆ ) / HNO ₃ sol.), Hexahydroxoplatinum (IV) sulfuric acid solution containing SO ₄ ^2- as a hydrophilic ion ((H ₂ Pt (OH) ₆ ) / H ₂ SO ₄ sol.), Tetraammineplatinum (II) hydroxide aqueous solution ([Pt (NH ₃ ) ₄ (OH) ₂ ]) having NH ₄ ⁺ as a hydrophilic ion. / H ₂ O sln.) Or the like.

  In the step 110, the amount of water prepared in the water storage unit 1020 can be, for example, 170 times the weight of the carrier contained in the catalyst. The amount of water prepared in the water storage unit 1020 is preferably 40 to 300 times the weight of the carrier contained in the catalyst, and 105 to 235 the weight of the carrier contained in the catalyst. The amount of water is more preferably doubled, and the amount of water is particularly preferably 160 to 180 times the weight of the support contained in the catalyst.

  Subsequently, in the process of step S140, the prepared catalyst, platinum compound solution, and water are charged into the stirring unit 1040, and stirred to generate a first mixed solution. And after that, a 1st liquid mixture is left still and a catalyst is collected on a bottom part (stationary process). As the stirring unit 1040, for example, a stirrer can be used. Moreover, as stirring time, it can be set as 5 hours, for example. The standing time can be, for example, 12 hours.

  FIG. 5A shows a state in which the catalyst Ctl is collected at the bottom of the container Bk in which the first mixed solution is stored in the first mixed solution in the standing step after stirring. FIG. 5A shows ions in the platinum compound solution PS that can be changed to acidic functional groups that modify the catalyst in a water evaporation step in step S160 described later in the first mixed solution. , “A”.

  Next, in the process of step S150, the removal liquid 1050 is used to remove the supernatant of the first mixed liquid (supernatant removal process). As the removal unit 1050, for example, a suction device can be used. FIG. 5B shows a state in which the supernatant of the first mixed solution is removed by the removing unit 1050 and the platinum compound solution is reduced in the supernatant removing step.

  Subsequently, in the process of step S160, the evaporation unit 1060 is used to evaporate water from the first mixed liquid after the supernatant is removed, and a mixture containing at least a catalyst and an acidic functional group (hereinafter also referred to as an acidic functional group-containing mixture). (Water evaporation step). In this case, in the acidic functional group-containing mixture, the acidic functional group is attached to the catalyst. As the evaporation unit 1060, a hot water bath apparatus that performs hot water bathing, a spray drying apparatus that performs spray drying, a vacuum drying apparatus that performs vacuum drying, and the like can be used. FIG. 5 (c) shows an evaporation section (hot water bath apparatus) 1060 containing hot water HW. FIG. 5 (c) shows how the acidic functional group-containing mixture Mix is generated by evaporating water from the first mixed solution by the evaporating unit (water bath device) 1060 in the water evaporation step. Yes. Specifically, FIG. 5C shows a state where an acidic functional group (indicated by “B” in the drawing) is attached to the catalyst Ctl in the acidic functional group-containing mixture Mix. In this case, the acidic functional group is also attached to the pores in the carrier in the catalyst Ctl.

  Next, in the process of step S170, the drying unit 1070 is used to perform first vacuum drying of the acidic functional group-containing mixture. The drying temperature for the first vacuum drying can be set to 60 ° C., for example. The drying time for the first vacuum drying can be 3 hours.

  Subsequently, in the step S180, the dry crushing unit 1080 is used to dry pulverize the acidic functional group-containing mixture dried in the step S170. As the dry grinding unit 1080, for example, a dry bead mill, a dry jet mill, or the like can be used.

  Next, in the process of step S190, first, the drying unit 1070 is used to perform the second vacuum drying of the acidic functional group-containing mixture pulverized in the process of step S180. The drying temperature for the second vacuum drying is preferably a relatively low temperature (a temperature lower than the drying temperature for the third vacuum drying described later), and can be, for example, 60 ° C. Moreover, as drying time of 2nd vacuum drying, it can be set as 3 hours, for example. Next, in the process of step S190, the drying unit 1070 is used to perform the third vacuum drying of the acidic functional group-containing mixture that has been subjected to the second vacuum drying. The drying temperature for the third vacuum drying is preferably a relatively high temperature (a temperature higher than the drying temperature for the second vacuum drying), for example, 130 ° C. Moreover, as drying time of 3rd vacuum drying, it can be set as 3 hours, for example. The third vacuum drying has at least an action of fixing acidic functional groups to the catalyst (including pores in the support) by performing drying at a relatively high temperature (that is, heat treatment). Such a catalyst having an acidic functional group fixed thereon is also called a treated catalyst.

  And in the process of step S195, water is added to the processed catalyst produced | generated at the process of step S190 using the water quantity adjustment part 1090, and a pre paste is manufactured. For example, the water amount adjusting unit 1090 produces a pre-paste by adding 20 g of water to 1 g of the treated catalyst.

  As described above, in the method of manufacturing the fuel cell according to the present embodiment, in the pre-paste manufacturing process (FIG. 3), the water is evaporated from the first mixed solution in the water evaporation process of step S160, thereby An acidic functional group-containing mixture containing at least a group is generated, and the acidic functional group-containing mixture is heat-treated in the third vacuum drying step of step S190 to catalyst the acidic functional group (including pores in the support). To settle. In this way, compared with the case where the first mixed solution is filtered, the disappearance of ions that can become acidic functional groups in the first mixed solution is suppressed, and many acidic functional groups generated from the ions are removed from the catalyst. It can be used as an acidic functional group for modification. Therefore, for example, the amount of the acidic functional group that modifies the catalyst can be controlled by adjusting the concentration of the platinum compound solution or adjusting the removal amount of the supernatant. Moreover, according to this structure, compared with the case where the 1st liquid mixture is filtered, the loss | disappearance of the ion which can become an acidic functional group in a 1st liquid mixture is suppressed, and many acidic functional groups which arise from the said ion, Since it can be used as an acidic functional group for modifying the catalyst, a suitable hydrophilic layer can be formed between the catalyst and the polymer electrolyte in the catalyst layer of the fuel cell. As a result, a stable PFF structure can be formed in the catalyst layer of the fuel cell, and the power generation efficiency of the fuel cell can be improved.

  Below, the specific example which controls the quantity of the acidic functional group which modifies a catalyst by adjusting the density | concentration of a platinum compound solution is shown. That is, in the moisture evaporation step (step S160) in the pre-paste manufacturing step (FIG. 3), the weight of acidic functional groups to be attached to the catalyst in the acidic functional group-containing mixture is determined. Next, the removal amount of the supernatant is determined in the supernatant removal step (step 150). Then, in the platinum compound solution preparation step (step S110), the concentration of the platinum compound to be prepared (in other words, the weight of ions that can be an acidic functional group contained in the platinum compound solution), the weight of the acidic functional group determined, Determine based on the determined amount of supernatant removal.

  Moreover, the specific example which controls the quantity of the acidic functional group which modifies a catalyst by adjusting the removal amount of a supernatant liquid is shown. That is, in the moisture evaporation step (step S160) in the pre-paste manufacturing step (FIG. 3), the weight of acidic functional groups to be attached to the catalyst in the acidic functional group-containing mixture is determined. Next, in the platinum compound solution preparation step (step S110), the concentration of the platinum compound to be prepared (in other words, the weight of ions that can be an acidic functional group contained in the platinum compound solution) is determined. In the supernatant removal step (step 150), the amount of supernatant removed is determined based on the determined weight of the acidic functional group and the determined concentration of the platinum compound.

  In the fuel cell manufacturing method of the present embodiment, in the pre-paste manufacturing process (FIG. 3), the catalyst in the first mixed solution is collected at the bottom (part) of the first mixed solution in the stationary step (step S140). Since the supernatant liquid of the first mixed solution is removed in the supernatant removing step (step S150), the amount of water evaporation is reduced when the water is evaporated from the first mixed solution in the water evaporation step (step S160). Can do. As a result, the working time of the water evaporation process (step S160) can be shortened.

  In addition, the process of step S140 of the pre-paste manufacturing process (FIG. 6) in the present embodiment is an example of the first mixed liquid preparation process, the process of step S160 is an example of the mixture generation process, and the process of step S190. Is an example of a heat treatment step.

B. Second embodiment:
FIG. 6 is a flowchart for explaining the pre-paste manufacturing process of the second embodiment. FIG. 7 is a diagram showing functional blocks of the pre-paste manufacturing apparatus 2000 in the second embodiment. In the fuel cell manufacturing method of the present embodiment, a part of the pre-paste manufacturing process is different from the pre-paste manufacturing process of the first embodiment. This is the same as the manufacturing method of the example fuel cell. Specifically, the pre-paste manufacturing process of the present embodiment includes steps S115 to S130 instead of the step S110 of the first embodiment. In the pre-paste manufacturing process of the present embodiment, the same step numbers are assigned to the same processes as the pre-paste manufacturing process of the first embodiment, and description thereof is omitted.

  Moreover, the pre-paste manufacturing apparatus 2000 of a present Example is provided with the centrifugal stirring part 2010, the wet grinding part 2020, and the platinum compound solution addition part 2030 compared with the pre-paste manufacturing apparatus 1000 of 1st Example. Although different, the other configurations are the same. In the pre-paste manufacturing apparatus 2000 of the present embodiment, the same components as those of the pre-paste manufacturing apparatus 1000 of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the pre-paste manufacturing process of the present embodiment, as shown in FIG. 6, in the process of step S115, a catalyst is prepared in the catalyst storage unit 1010 and water is prepared in the water storage unit 1020. The amount of water prepared in the water storage unit 1020 can be, for example, 4 to 40 times the weight of the carrier contained in the catalyst.

  Next, in the process of step S120, the prepared catalyst and water are put into the centrifugal stirring unit 2010, and centrifugal stirring is performed to generate a second mixed liquid. As the centrifugal stirring unit 2010, for example, a hybrid mixer can be used.

  Subsequently, in the process of step S125, using the wet pulverization unit 2020, water is added to the second mixed liquid, and wet pulverization is performed on the catalyst in the third mixed liquid as the third mixed liquid. As the wet pulverization unit 2020, for example, an ultrasonic homogenizer, a wet jet mill, a hole mill, and a bead mill can be used. When an ultrasonic homogenizer is used as the wet pulverization unit 2020, for example, the frequency of the ultrasonic homogenizer may be set to 20 kHz, and the wet pulverization may be performed for 10 minutes. In this step, the amount of water added to the second mixed solution can be adjusted, for example, so that the amount of water in the third mixed solution is 100 times the weight of a single substance contained in the catalyst. preferable.

  Next, in step 130, a platinum compound solution is prepared in the platinum compound solution storage unit 1030 and water is newly prepared in the water storage unit 1020. Then, the prepared platinum compound solution, the prepared water, and the third mixed liquid that has been wet pulverized are put into the stirring unit 1040 using the platinum compound solution adding unit 2030. In the next step S140, stirring is performed using the stirring unit 1040 to generate the first mixed liquid. In this step, the amount of water introduced into the stirring unit 1040 can be adjusted, for example, so that the amount of water in the first mixed solution is 170 times the weight of a single substance contained in the catalyst. preferable.

  As described above, in the fuel cell manufacturing method of the present embodiment, in addition to the operations and effects of the fuel cell manufacturing method of the first embodiment, the following operations and effects can be achieved. That is, in the pre-paste manufacturing process (FIG. 6), since the catalyst is wet-ground in the process of step S125, the catalyst in the third mixed liquid (first mixed liquid) can be finely divided. Therefore, the surface area of the catalyst in the pre-paste can be increased, and the power generation efficiency of the fuel cell can be improved.

  In the fuel cell manufacturing method of this embodiment, in the pre-paste manufacturing process (FIG. 6), the second mixed solution is centrifugally stirred in step S120. If it does in this way, the fine bubble in a 3rd liquid mixture (1st liquid mixture) can be removed.

  In addition, the process of step S115 of the pre-paste manufacturing process (FIG. 3) in this embodiment is an example of the second mixed solution preparation process, the process of step S125 is an example of the pulverization process, and the process of step S130 is It is an example of a liquid mixture addition process. Moreover, the process of step S120 is an example of a centrifugal stirring process.

C. Third embodiment:
FIG. 8 is a flowchart for explaining the pre-paste manufacturing process of the third embodiment. FIG. 9 is a diagram showing functional blocks of the pre-paste manufacturing apparatus 3000 in the third embodiment. In the fuel cell manufacturing method of the present embodiment, a part of the pre-paste manufacturing process is different from the pre-paste manufacturing process of the first embodiment. This is the same as the manufacturing method of the example fuel cell. Specifically, the pre-paste manufacturing process of the present embodiment includes a process of step S135 instead of the process of step S110 of the first embodiment, and includes a process of step S145 instead of step S140 and step S150. ing. In the pre-paste manufacturing process of the present embodiment, the same step numbers are assigned to the same processes as the pre-paste manufacturing process of the first embodiment, and description thereof is omitted.

  In addition, the pre-paste manufacturing apparatus 3000 of the present embodiment does not include the stirring unit 1040 and the removal unit 1050, but includes the centrifugal stirring unit 2010, as compared with the pre-paste manufacturing apparatus 1000 of the first example. Although different, other configurations are the same. In the pre-paste manufacturing apparatus 3000 of the present embodiment, the same reference numerals are given to the same configurations as those of the pre-paste manufacturing apparatus 1000 of the first embodiment, and description thereof is omitted.

  In the pre-paste manufacturing process of the present embodiment, as shown in FIG. 8, first, in the process of step 135, the catalyst is stored in the catalyst storage unit 1010, the platinum compound solution is stored in the platinum compound solution storage unit 1030, and the water is stored in the water storage unit. Prepare at 1020, respectively. The amount of water prepared in the water storage unit 1020 can be 4 to 40 times the weight of the support contained in the catalyst.

  Next, in the process of step S145, the prepared catalyst, platinum compound solution, and water are put into the centrifugal stirring unit 2010, and centrifugal stirring is performed to generate a fourth mixed solution. In the next step S160, water is evaporated from the fourth mixture to produce an acidic functional group-containing mixture.

  As described above, in the fuel cell manufacturing method of the present embodiment, in addition to the operations and effects of the fuel cell manufacturing method of the first embodiment, the following operations and effects can be achieved. That is, in the pre-paste manufacturing process (FIG. 8), in the process of step S145, the catalyst, the platinum compound solution, and water are mixed and centrifuged, so the fine bubbles in this mixed liquid (fourth mixed liquid) Can be removed.

  In addition, the process of step S135 of the pre-paste manufacturing process (FIG. 8) in a present Example is an example of a 1st liquid mixture preparation process, and the process of step S145 is an example of a centrifugal stirring process.

D. Fourth embodiment:
FIG. 10 is a flowchart for explaining the pre-paste manufacturing process of the fourth embodiment. FIG. 11 is a diagram showing functional blocks of the pre-paste manufacturing apparatus 4000 in the fourth embodiment. In the fuel cell manufacturing method of the present embodiment, a part of the pre-paste manufacturing process is different from the pre-paste manufacturing process of the third embodiment. This is the same as the manufacturing method of the example fuel cell. Specifically, the pre-paste manufacturing process of the present embodiment includes the process of step S147 between the processes of step S145 and step S160 of the third embodiment. In the pre-paste manufacturing process of the present embodiment, the same step numbers are assigned to the same processes as the pre-paste manufacturing process of the third embodiment, and description thereof is omitted.

  Further, the pre-paste manufacturing apparatus 4000 of this embodiment is different from the pre-paste manufacturing apparatus 3000 of the third embodiment in that it includes a wet pulverization unit 2020, but the other configurations are the same. . In the pre-paste manufacturing apparatus 4000 of the present embodiment, the same components as those of the pre-paste manufacturing apparatus 3000 of the third embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the pre-paste manufacturing process of the present embodiment, as shown in FIG. 10, in the process of step 147, wet pulverization is performed on the catalyst in the fourth mixed liquid using the wet pulverization unit 2020.

  As described above, in the fuel cell manufacturing method of the present embodiment, in addition to the operations and effects of the fuel cell manufacturing method of the third embodiment, the following operations and effects can be achieved. That is, in the pre-paste manufacturing process (FIG. 10), since the catalyst is wet pulverized in the process of step S147, the catalyst in the fourth mixed solution can be finely divided. Therefore, the surface area of the catalyst in the pre-paste can be increased, and the power generation efficiency of the fuel cell can be improved.

  In addition, the process of step S147 of the pre-paste manufacturing process (FIG. 10) in a present Example is an example of a grinding | pulverization process.

E. Variation:
The present invention is not limited to the above-described embodiments and application examples, and can be carried out in various modes without departing from the gist thereof. For example, the following modifications are possible.

First modification:
In the pre-paste manufacturing process (FIG. 6) of the second embodiment, the process of step S130 is performed after step 125, but is not limited thereto. For example, the step 130 may be performed before the step 125. That is, a platinum compound solution and water may be added to the second mixed solution and mixed, and then wet pulverization may be performed on the catalyst in the mixed solution.

Second modification:
In the pre-paste manufacturing process (FIGS. 8 and 10) of the third embodiment and the fourth embodiment, the supernatant removal process (FIG. 3: step S150) of the first embodiment is performed before the water evaporation process (step S160). ) May be performed.

Third modification:
In the pre-paste manufacturing process of the first embodiment and the second embodiment, instead of the stationary process (FIG. 3, FIG. 6: step 140), the centrifugal separation device is used to perform the centrifugal separation. The catalyst may be collected in a part.

    DESCRIPTION OF SYMBOLS 10 ... Electrolyte membrane, 20 ... Cathode side catalyst layer, 30 ... Anode side catalyst layer, 40 ... Gas diffusion layer, 50 ... Gas diffusion layer, 60 ... Separator, 100 ... Fuel cell, 1000, 2000, 3000, 4000 ... Pre-paste manufacturing apparatus, 1010 ... Catalyst housing unit, 1020 ... Water housing unit, 1030 ... Platinum compound solution housing unit, 1040 ... Stirring 1050 ... removal unit 1060 ... evaporation unit 1070 ... drying unit 1080 ... dry pulverization unit 1090 ... water amount adjustment unit 2010 ... centrifugation stirring unit 2020 .. .Wet grinding part, 2030 ... Platinum compound solution addition part

Claims (4)

A method for producing a catalyst for a fuel cell, comprising:
A first mixed solution preparing step of preparing a first mixed solution including a catalyst including a carrier on which catalytic metal particles are supported, a solution of a platinum compound including an acidic functional group, and water;
Said water is evaporated from the first mixture preparing step wherein the first mixture is prepared by, and the catalyst, and the acidic functional groups contained in the platinum compound, and a mixture generating step of generating a mixture including at least ,
A heat treatment step of heat treating the mixture produced in the mixture production step, the heat treatment step having at least an action of fixing the acidic functional group to the catalyst;
With
The first mixed liquid preparation step includes
A second mixed solution preparing step of preparing a second mixed solution containing the catalyst and the water;
A first pulverization step of wet pulverizing the catalyst after the second mixed solution preparation step;
After the second mixture preparing step, the the second mixture, the mixture added to produce the first mixture solution was added of the platinum compound,
Comprising
A method for producing a catalyst for a fuel cell. A method for producing a catalyst for a fuel cell, comprising:
A first mixed solution preparing step of preparing a first mixed solution including a catalyst including a carrier on which catalytic metal particles are supported, a solution of a platinum compound including an acidic functional group, and water;
Said water is evaporated from the first mixture preparing step wherein the first mixture is prepared by, and the catalyst, and the acidic functional groups contained in the platinum compound, and a mixture generating step of generating a mixture including at least ,
A heat treatment step of heat treating the mixture produced in the mixture production step, the heat treatment step having at least an action of fixing the acidic functional group to the catalyst;
With
After the first mixed solution preparation step and before the mixture generating step, the catalyst in the first mixed solution is collected in a part of the first mixed solution, and the supernatant of the first mixed solution is removed. Comprising the steps,
A method for producing a catalyst for a fuel cell. A method for producing a fuel cell catalyst according to claim 1,
The first mixed liquid preparation step includes
After the second mixed solution preparation step, the first mixed solution, or a centrifugal stirring step of centrifugally stirring the second mixed solution,
A method for producing a catalyst for a fuel cell. A method for producing a fuel cell catalyst according to any one of claims 1 to 3,
The acidic functional group is any one of a nitric acid group, a nitrous acid group, a sulfonic acid group, a hydroxyl group, a carboxyl group, a carbonyl group, and a halogen group.
A method for producing a catalyst for a fuel cell.

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