Manufacturing system and method for electrode catalysts

Abstract

The present invention provides a manufacturing system and a manufacturing method for an electrode catalyst. The manufacturing system and method eliminate the need for an operator to transfer the electrode catalyst precursor and shorten the drying time of the electrode catalyst precursor. The electrode catalyst manufacturing system (10) includes an electrode catalyst precursor manufacturing apparatus (12), a cleaning apparatus (13), and a drying apparatus (14). The drying apparatus (14) comprises a unit that performs an introduction step (S31) of introducing an electrode catalyst precursor into a container body (202), a drying step (S32) of drying the electrode catalyst precursor by stirring and mixing it with stirring blades (204) while heating the container body (202), a cooling step (S33) of cooling the container body (202) by stirring and mixing the electrode catalyst precursor with stirring blades while cooling the container body (202), a slow oxidation step (S34) of supplying air to the container body (202) to slowly oxidize the electrode catalyst precursor, and an extraction step (S35) of removing the electrode catalyst precursor from the container body (202).

Description

Technical Field

[0001] This invention relates to a system and method for manufacturing catalysts for electrodes. Background Technology

[0002] So-called solid polymer fuel cells (PEFCs) operate at temperatures ranging from room temperature to approximately 80°C. Furthermore, PEFCs can achieve lightweight construction by using inexpensive and widely available plastics in the components that make up the fuel cell body. Moreover, PEFCs allow for the thinning of the solid polymer electrolyte membrane, thereby reducing resistance and thus making it easier to reduce power generation losses. Due to these advantages, PEFCs can be applied in areas such as fuel cell vehicles and residential cogeneration systems.

[0003] As electrode catalysts for PEFCs, it is known, for example, to be electrode catalysts in which platinum (Pt) or platinum (Pt) alloys, which are components of the electrode catalyst, are supported on carbon as a support. When such electrode catalysts are used as electrode catalysts for fuel cells, if the content of impurities from the raw materials or impurities introduced by the manufacturing equipment is high, sufficient catalytic activity cannot be obtained and / or corrosion of the catalyst layer occurs, shortening the life of the fuel cell. Therefore, it is preferable to control the impurity content of the electrode catalyst to a low level. Here, impurities include chemical species belonging to halogens (ions or ionic salts, etc.) and organic compounds (organic acids, organic acid salts, condensates of organic acids), etc.

[0004] Therefore, after manufacturing the electrode catalyst precursor, which serves as a raw material for the electrode catalyst, a chlorine removal process is sometimes performed. In this case, a process of drying the electrode catalyst precursor is performed after a washing process. For example, Patent Documents 1 and 2 describe drying methods after washing that can use rack dryers, rotary dryers, airflow dryers, spray dryers, stirred dryers, and freeze dryers.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2013-158674

[0008] Patent Document 2: Japanese Patent Application Publication No. 2014-42910 Summary of the Invention

[0009] The problem the invention aims to solve

[0010] For example, when drying electrode catalyst precursors using a drying cabinet, to achieve efficient drying, sometimes the wet electrode catalyst precursor lumps are finely crushed before being placed in the drying cabinet for drying, and then the dried electrode catalyst precursor lumps are finely pulverized after drying. In this conventional method of drying electrode catalyst precursors, a dedicated crusher is required to crush the cleaned wet electrode catalyst precursor, and a hammer crusher is needed to pulverize the dried electrode catalyst precursor. This necessitates transferring the electrode catalyst precursor from the crusher to the dryer, and then from the dryer to the hammer crusher. However, platinum, which constitutes the electrode catalyst precursor, is highly reactive; if it comes into rapid contact with oxygen in the air, there is a risk of combustion, therefore this operation must be performed with caution. Furthermore, in the method of drying electrode catalyst precursors using a drying cabinet, since the electrode catalyst precursor is dried by statically holding it and through radiative heat transfer, the drying speed is slow and the time consumption is long. While Patent Documents 1 and 2 describe that the drying of catalysts for fuel cells can be carried out by a stirring dryer, they do not describe the specific structure or operating conditions of the stirring dryer.

[0011] In view of the above, the present invention provides a manufacturing system and method for an electrode catalyst. By eliminating the operator's task of transferring the electrode catalyst precursor and shortening the drying time of the electrode catalyst precursor, it is possible to significantly reduce the labor and time required for manufacturing the electrode catalyst.

[0012] Solution for solving the problem

[0013] To address the aforementioned problems, the present invention provides a manufacturing system for an electrode catalyst, which is used to manufacture an electrode catalyst, the manufacturing system comprising:

[0014] An apparatus for manufacturing electrode catalyst precursors, which is used to manufacture electrode catalyst precursors that are raw materials for electrode catalysts.

[0015] A cleaning apparatus for cleaning the catalyst precursor used in the electrode; and

[0016] A drying apparatus that dries the electrode catalyst precursor, which has been cleaned by the cleaning apparatus, using a stirring device equipped with stirring blades having helical ribbon-shaped rotating blades.

[0017] The drying apparatus comprises units that perform the following processes:

[0018] The introduction process involves introducing the electrode catalyst precursor into the container body of the stirring treatment device;

[0019] The drying process involves heating the container body while simultaneously reducing the pressure, and mixing the electrode catalyst precursor within the container body by stirring with the stirring blades, thereby drying the electrode catalyst precursor.

[0020] The cooling process involves cooling the container body while simultaneously reducing pressure, and cooling the electrode catalyst precursor within the container body by stirring and mixing the catalyst precursor with the stirring blades.

[0021] A slow oxidation process, in which air is supplied into the container body to slowly oxidize the catalyst precursor for the electrode; and

[0022] The removal process involves removing the electrode from the container body using a catalyst precursor.

[0023] The manufacturing system for the electrode catalyst may be such that the stirring blades have:

[0024] A rotating spindle that rotates the stirring blades by means of a drive device;

[0025] The spiral ribbon-shaped rotating blades for stirring and mixing the electrode catalyst precursor within the container body; and

[0026] The rotary wing support connected to the main rotating shaft and the helical ribbon rotary wing, wherein

[0027] The main rotating shaft and the rotating blade support are formed as hollow tubes.

[0028] The rotor support has a gas ejection port on the lower side of its front end.

[0029] The rotating spindle is connected to the gas flow channel.

[0030] In addition, the present invention provides a method for manufacturing an electrode catalyst, the method comprising:

[0031] An electrode catalyst precursor manufacturing step, which is used to manufacture an electrode catalyst precursor as a raw material for an electrode catalyst.

[0032] A cleaning step, which cleans the catalyst precursor for the electrode; and

[0033] The drying step involves drying the cleaned electrode, which was cleaned in the cleaning step, using a stirring device equipped with stirring blades having a spiral ribbon-shaped rotating blade.

[0034] The drying step includes:

[0035] The drying process involves heating the container body while simultaneously reducing the pressure, and drying the electrode catalyst precursor within the container body by stirring and mixing the catalyst precursor with the stirring blades.

[0036] The cooling process involves cooling the container body while simultaneously reducing pressure, and cooling the electrode catalyst precursor within the container body by stirring and mixing the catalyst precursor with the stirring blades; and

[0037] The slow oxidation process involves supplying air into the container body to slowly oxidize the catalyst precursor for the electrode.

[0038] The method for manufacturing the electrode catalyst may further include a removal step of removing the electrode catalyst precursor from the container body, wherein...

[0039] The removal process may include a scraping process in which gas is ejected downward from a gas ejection port located at the front end of the rotor support pillar that supports the spiral ribbon rotor.

[0040] The method for manufacturing the catalyst for the electrode may further include:

[0041] The first analytical step involves performing a physical property analysis on the electrode catalyst precursor obtained after the drying step.

[0042] The re-slurrying step involves mixing the electrode catalyst precursor obtained in the drying step with ion-exchanged water to prepare a slurry again; and

[0043] The catalyst filter cake preparation step involves drying the slurry obtained from the re-slurrying step to prepare multiple solid catalyst filter cakes with a moisture content adjusted to a specified range.

[0044] In the method for manufacturing the catalyst for the electrode, the stirring drying device used in the catalyst filter cake preparation step may be the stirring treatment device.

[0045] In the method for manufacturing the catalyst for the electrode, a reactor equipped with a stirring device may be used in the reslurry step.

[0046] In the method for manufacturing the catalyst for the electrode, the reactor may be the stirring treatment device.

[0047] In the method for manufacturing the electrode catalyst, the moisture content of the catalyst filter cake can be less than 80 wt%.

[0048] The method for manufacturing the catalyst for the electrode may further include a second analytical step, which measures the moisture content of the catalyst filter cake obtained after the catalyst filter cake preparation step.

[0049] The effects of the invention

[0050] According to the manufacturing system and method for electrode catalysts of the present invention, by eliminating the operation of transferring the electrode catalyst precursor by the operator and shortening the drying time of the electrode catalyst precursor, it is possible to significantly reduce the labor and time required to manufacture electrode catalysts with low halogen content, especially low chlorine content. Attached Figure Description

[0051] Figure 1 This is a block diagram illustrating a preferred embodiment of the manufacturing system for the electrode catalyst of the present invention.

[0052] Figure 2 This is a side view showing a preferred embodiment of the cleaning apparatus for the manufacturing system and method of the electrode catalyst of the present invention.

[0053] Figure 3 This is a perspective view showing the operating state of the dehydration device in the closed-plate process of the manufacturing system and method for manufacturing electrode catalysts of the present invention.

[0054] Figure 4 This is a perspective view showing the operating state of the dehydration device in the pressing process of the manufacturing system and method for manufacturing electrode catalysts of the present invention.

[0055] Figure 5 This is a perspective view showing the operating state of the dehydration device in the forward washing step of the manufacturing system and method for manufacturing electrode catalysts of the present invention.

[0056] Figure 6 This is a perspective view showing the operating state of the dehydration device in the backwashing process of the manufacturing system and method for manufacturing the electrode catalyst of the present invention.

[0057] Figure 7 This is a perspective view showing the operating state of the dehydration device in the plate-opening process of the manufacturing system and method for manufacturing electrode catalysts of the present invention.

[0058] Figure 8 This is a perspective view showing the operating state of the dehydration device in the filter cake stripping process of the electrode catalyst manufacturing system and method of the present invention.

[0059] Figure 9This is a perspective view showing the operating state of the dewatering device in the filter cloth cleaning process of the electrode catalyst manufacturing system and method of the present invention.

[0060] Figure 10 This is a perspective view showing the operating state of the dehydration device in the pressing process of the electrode catalyst manufacturing system and method of the present invention.

[0061] Figure 11 This is a schematic diagram illustrating a preferred embodiment of the drying apparatus of the manufacturing system and method for the electrode catalyst of the present invention.

[0062] Figure 12 This is a perspective view showing a preferred embodiment of the stirring blades of the drying apparatus in the manufacturing system and method for manufacturing the electrode catalyst of the present invention.

[0063] Figure 13 is a schematic diagram showing the operating state of a preferred embodiment of the drying apparatus in the drying step of the manufacturing system and method for manufacturing the electrode catalyst of the present invention.

[0064] Figure 14 To indicate an electrode catalyst (core) that can be manufactured using the electrode catalyst manufacturing system and method of the present invention · A schematic cross-sectional view of an example of the structure of a shell catalyst.

[0065] Figure 15 To indicate an electrode catalyst (core) that can be manufactured using the electrode catalyst manufacturing system and method of the present invention · A schematic cross-sectional view of another example of the structure of a shell catalyst.

[0066] Figure 16 To indicate an electrode catalyst (core) that can be manufactured using the electrode catalyst manufacturing system and method of the present invention · A schematic cross-sectional view of another example of the structure of a shell catalyst.

[0067] Figure 17 To indicate an electrode catalyst (core) that can be manufactured using the electrode catalyst manufacturing system and method of the present invention · A schematic cross-sectional view of another example of the structure of a shell catalyst.

[0068] Figure 18 This is a flowchart illustrating a preferred embodiment of the method for manufacturing the electrode catalyst of the present invention.

[0069] Figure 19 This is a flowchart illustrating a preferred embodiment of the cleaning steps in the method for manufacturing the electrode catalyst of the present invention.

[0070] Figure 20 This is a flowchart illustrating a preferred embodiment of the drying step in the method for manufacturing the electrode catalyst of the present invention.

[0071] Figure 21 This is a block diagram illustrating another preferred embodiment of the manufacturing system for the electrode catalyst of the present invention.

[0072] Figure 22 This is a flowchart illustrating a preferred embodiment of the reslurrying step in the method for manufacturing the electrode catalyst of the present invention.

[0073] Figure 23 This is a schematic diagram illustrating the dropping funnel used in the mixing test of the reslurry step in the method for manufacturing the electrode catalyst of the present invention.

[0074] Figure 24 This is a graph showing the time-varying changes in the heating temperature of the container body, the tank temperature of the container body, the temperature of the catalyst precursor for the electrode, and the moisture content of the filter cake in the drying process of the present invention.

[0075] Figure 25 This is a graph showing the time-varying changes in the heating temperature of the container body, the tank temperature of the container body, the temperature of the catalyst precursor for the electrode, and the moisture content of the filter cake in the drying process of the present invention.

[0076] Symbol Explanation

[0077] 1. Electrode catalyst

[0078] 2. Carrier

[0079] 3. Catalyst particles

[0080] 4 cores

[0081] 5. Shell

[0082] 10. Electrode Catalyst Manufacturing System

[0083] 12 Electrode Catalyst Precursor Manufacturing Unit

[0084] 13 Cleaning device

[0085] 14. Drying device

[0086] 201 Mixing and processing device

[0087] 202 Container Body

[0088] 204 stirring blades

[0089] 222 Rotary spindle

[0090] 223 Spiral ribbon rotor

[0091] 224 arms (rotor struts)

[0092] 226 Gas ejection port

[0093] 152 Reactor

[0094] S1 Electrode Catalyst Precursor Manufacturing Steps

[0095] S2 Cleaning Steps

[0096] S3 Drying Step

[0097] S31 Introduction Process

[0098] S32 Drying process

[0099] S33 Cooling process

[0100] S34 Slow Oxidation Process

[0101] S35 Removal Process

[0102] S36 First property analysis step (first analysis procedure)

[0103] S40 re-pulping step

[0104] S50 catalyst filter cake preparation steps

[0105] S60 Second property analysis step (second analysis procedure) Detailed Implementation

[0106] Hereinafter, preferred embodiments of the manufacturing system and manufacturing method for the electrode catalyst of the present invention will be described with reference to the accompanying drawings.

[0107] <Electrode Catalyst Manufacturing System>

[0108] Figure 1 This is a schematic block diagram illustrating a manufacturing system for an electrode catalyst according to the first embodiment. The manufacturing system 10 for the electrode catalyst includes: manufacturing a catalyst 1 for the electrode (see reference 1). Figure 18 The electrode catalyst precursor manufacturing apparatus 12, which is a raw material for an electrode catalyst precursor, consists of an electrode catalyst precursor manufacturing apparatus 12, a cleaning apparatus 13 for cleaning the electrode catalyst precursor by a filter press, and a stirring treatment apparatus equipped with stirring blades having a spiral ribbon-shaped rotating blade. The cleaned electrode catalyst precursor 41 (see reference 13) is then dried by the cleaning apparatus 13. Figure 19 Drying device 14.

[0109] (Electrode catalyst precursor manufacturing apparatus)

[0110] Electrode catalyst precursor manufacturing apparatus 12 manufactures an electrode catalyst precursor, which serves as a raw material for electrode catalyst 1. The apparatus 12 includes a reaction process execution unit 21 that performs a reaction process for manufacturing the electrode catalyst precursor. In the reaction process, the electrode catalyst precursor, which serves as a raw material for electrode catalyst 1, is manufactured by supporting the catalyst components (core 4, shell 5) of electrode catalyst 1 on a carrier 2 (see reference). Figure 14 The method for manufacturing the electrode catalyst precursor is not particularly limited as long as it enables the catalyst component of the electrode catalyst 1 to be supported on the support 2. Examples of manufacturing methods include, for example, impregnation methods in which a solution containing the catalyst component of the electrode catalyst 1 is contacted with the support 2 and the catalyst component is impregnated in the support 2; liquid-phase reduction methods in which a reducing agent is added to a solution containing the catalyst component of the electrode catalyst 1; electrochemical deposition methods such as underpotential deposition (UPD); chemical reduction methods; reduction deposition methods using adsorbed hydrogen; surface leaching methods of alloy catalysts; displacement electroplating; sputtering; and vacuum evaporation methods.

[0111] (Cleaning device)

[0112] The cleaning apparatus 13 cleans the electrode catalyst precursor manufactured by the electrode catalyst precursor manufacturing apparatus 12 using a filter press. In this cleaning apparatus 13, filtration and dehydration are performed simultaneously with the cleaning of the electrode catalyst precursor.

[0113] Figure 2 This illustrates an example of a cleaning apparatus 13 for filter press operation. In the cleaning apparatus 13 shown in the same figure, a plurality of dewatering devices 104 are arranged horizontally side-by-side on guide rails 103 mounted on a front frame 101 and a rear frame 102. These dewatering devices 104 are supported in a manner that allows them to move horizontally along the guide rails 103. An electric cylinder 105, for example, is supported on the rear frame 102, and a pressing member 106, which reciprocates using the driving force of the electric cylinder 105, presses the dewatering devices 104. Such a cleaning apparatus 13 for a filter press is known in the past, and is known in, for example, the cleaning apparatus described in Japanese Patent No. 5950207. In particular, regarding the dewatering devices 104, is known in, for example, the dewatering apparatus described in Japanese Patent No. 5327000.

[0114] A general description of the cleaning process using a filter press is provided (see reference). Figures 3 to 10First, once the raw liquid 30 is supplied to the filter chamber 112 between the closed filter plates 111 and 111', the raw liquid 30 is filtered through the filter cloth 113, and the filtrate 42 is discharged to the outside. The solids captured by the filter cloth 113 are dehydrated while forming a filter cake layer. After dehydration is completed, the electric cylinder 105 is retracted, and once multiple filter plates 111 and 111' are opened simultaneously, the dehydrated filter cake 40 is discharged while the filter cloth 113 is lowered.

[0115] like Figure 1 As shown in the flowchart, the cleaning apparatus 13 includes a closing plate process unit 31, a pressing plate process unit 32, a forward washing process unit 33, a backwashing process unit 34, a plate opening process unit 35, a filter cake peeling process unit 36, and a filter cloth cleaning process unit 37, each for performing a closing plate process, a pressing plate process, a forward washing process, a backwashing process unit 34, a plate opening process unit 35, a filter cake peeling process unit 36, and a filter cloth cleaning process unit 37. Hereinafter, the following will describe... Figure 19 The structure of each step S21 to S27 shown in the flowchart of the method for manufacturing the electrode catalyst 1 will be described.

[0116] [Closing process]

[0117] The plate closing process S21 is a process of pressing the filter plates 111 and 111' to form the filter chamber 112, and it is carried out by the plate closing process execution unit 31. Figure 3 To extract in Figure 2 The figure shows a dewatering device 104 in the cleaning device 13, and illustrates a preferred embodiment of the operation state in the plate closing process S21. The plate closing process execution unit 31 moves the pressing member 106 towards the front frame 101 by driving the electric cylinder 105, thereby bringing the two filter plates 111, 111' of the dewatering device 104 close together and pressing them together to form the filter chamber 112.

[0118] [Pressing process]

[0119] The pressing process S22 is a process in which liquid (stock solution) 30 containing the catalyst precursor for the electrode is pressed from the stock solution supply pipe 114 into the filter chamber 112 for filtration, and the filtrate 42 is discharged from the filtrate discharge outlets 115, 115', and is performed by the pressing process execution unit 32. Figure 4 To extract in Figure 2The figure shows a dehydration device 104 in the cleaning apparatus 13, illustrating a preferred embodiment of the operation state during the pressing process S22. Once the liquid 30 containing the electrode catalyst precursor is pressed into the filter chamber 112 from the raw liquid supply pipe 114 by the pressing process execution unit 32, the water in the liquid 30 containing the electrode catalyst precursor seeps through the filter cloth 113 into the filter bed 116 and is discharged to the outside from the filtrate discharge ports 115, 115'. Thus, the liquid 30 containing the electrode catalyst precursor pressed into the filter chamber 112 is filtered. That is, the solid components in the liquid 30 containing the electrode catalyst precursor remain in the filter chamber 112 as the filter cake 40 containing the electrode catalyst precursor, and the water in the liquid 30 containing the electrode catalyst precursor is discharged to the outside as the filtrate 42.

[0120] Furthermore, in the pressing process S22, the filter cake 40 containing the electrode catalyst precursor is formed to have a thickness within a range determined by prior experiments. The thickness of the filter cake 40 is determined in advance through experiments, taking into account the required degree of cleaning and cleaning time relative to the electrode catalyst precursor used.

[0121] In the case where conductive carbon is used as a support for the electrode catalyst, the thickness T of the filter cake 40 during the pressing step S22 is preferably adjusted to 5 to 10 mm. If the thickness T of the filter cake 40 is less than 10 mm, a sufficient cleaning effect can be easily obtained by adjusting the cleaning time of the forward washing and / or backwashing steps described later. If the thickness T of the filter cake 40 exceeds 10 mm, the tendency to fail to obtain a sufficient cleaning effect increases even if the cleaning time of the forward washing and / or backwashing steps described later is extended.

[0122] In addition, if the thickness T of the filter cake 40 is 5 mm or more, it is difficult for cracks to form on the filter cake, which can prevent the formation of a path that allows washing water to flow from the upstream surface of the filter cake to the downstream surface of the filter cake without passing through the interior of the filter cake.

[0123] [Straight Wash Process]

[0124] The forward washing process S23 is a process in which washing water 43 is supplied from the raw liquid supply pipe 114 to the filter chamber 112, and after passing through the filter cake 40 containing the electrode catalyst precursor, it is discharged from the filtrate discharge outlets 115 and 115', and is carried out by the forward washing process execution unit 33. Figure 5 To extract in Figure 2The figure shows a dehydration device 104 in the cleaning apparatus 13, illustrating a preferred embodiment of its operation in the forward washing process S23. Through the forward washing process execution unit 33, cleaning water 43 flows from the raw liquid supply pipe 114 to the filtrate discharge outlets 115, 115', cleaning the filter cake 40 containing the electrode catalyst precursor that remained in the filter chamber 112 during the pressing process S22. This reduces the conductivity ρ of the filtrate as measured by the JIS standard test method (JIS K0522), and also reduces the halogen content of the electrode catalyst precursor, particularly the chlorine content.

[0125] In the forward washing step S23, during the washing process, when the conductivity ρ of the filtrate reaches or falls below a predetermined value, it is preferable to switch the temperature of the washing water 43. For example, when the conductivity ρ of the filtrate reaches or falls below the predetermined value, the washing water 43 can be switched from room temperature water (e.g., 23°C) to heated water (e.g., 70°C). The predetermined value of the conductivity ρ of the filtrate is preferably selected from the range of 20 to 40 μS / cm. The temperature of the room temperature water is preferably 20 to 25°C. The temperature of the heated water is preferably 60 to 80°C.

[0126] [Backwashing process]

[0127] The backwashing process S24 is a process in which cleaning water 43 is supplied from the filtrate outlet 115 to the filter chamber 112 and passes through the filter cake 40 containing the electrode catalyst precursor, and then discharged from a different filtrate outlet 115' than the filtrate outlet 115 from which the cleaning water 43 is supplied, and is carried out by the backwashing process execution unit 34. Figure 6 To extract in Figure 2 The figure shows a dehydration device 104 in the cleaning apparatus 13, illustrating a preferred embodiment of its operation in the backwashing process S24. The dehydration device 104 has, for example, at least two filtrate discharge ports 115 and 115'. In contrast to the forward washing process S23, the backwashing process execution unit 34 cleans the filter cake 40 containing the electrode catalyst precursor remaining in the filter chamber 112 by flowing cleaning water 43 from the filtrate discharge port 115 to the filter chamber 112. The filtrate 42 is discharged, for example, from a different filtrate discharge port 115' than the one supplying the cleaning water 43. By performing the backwashing process S24, the conductivity ρ of the filtrate can be further reduced, and the halogen content of the electrode catalyst precursor, particularly the chlorine content, can be further reduced.

[0128] Although room temperature water (e.g., 23°C) can be used for backwashing in step S24, the conductivity ρ of the filtrate has decreased to a certain extent by the end of step S23. Therefore, it is preferable to start washing with heated water (e.g., 70°C) from the beginning. The temperature of the heated water is preferably 60–80°C.

[0129] [Panel Opening Process]

[0130] The plate opening process S25 is the process of opening the filter plates 111 and 111' that form the filter chamber 112, and it is carried out by the plate opening process execution unit 35. Figure 7 To extract in Figure 2 The figure shows one of the dewatering devices 104 in the cleaning apparatus 13, and illustrates a preferred embodiment of its operation in the plate-opening process S25. The plate-opening process execution unit 35 drives the electric cylinder 105 to release the clamping of the dewatering device 104 by moving the pressing member 106 toward the rear frame 102 side. In this way, the two filter plates 111, 111' of the dewatering device 104 are pulled apart, thereby opening the filter chamber 112.

[0131] [Cake Removal Process]

[0132] The filter cake stripping process S26 is a process in which the filter cloth is lowered, thereby stripping the dehydrated filter cake 40 containing the electrode catalyst precursor, and is performed by the filter cake stripping process execution unit 36. Figure 8 For extraction Figure 2 The figure shows a dewatering device 104 in the cleaning apparatus 13, and illustrates a preferred embodiment of its operation in the cake stripping process S26. Once the two filter plates 111 and 111' of the dewatering device 104 are separated to a given distance by the cake stripping process execution unit 36, the filter cloth 113, holding the filter cake 40 containing the electrode catalyst precursor, moves downward. In this way, the filter cake 40 containing the electrode catalyst precursor is automatically stripped from the filter cloth 113.

[0133] [Filter cloth cleaning process]

[0134] The filter cloth cleaning process S27 is a process of cleaning the filter cloth 113 with cleaning water 43 after the filter cake peeling process S26, and is performed by the filter cloth cleaning process execution unit 37. Figure 9 To extract in Figure 2The figure shows a preferred embodiment of the dewatering device 104 in the cleaning apparatus 13, illustrating the operating state during the filter cloth cleaning process S27. After the filter cake 40 containing the electrode catalyst precursor is peeled off from the filter cloth 113, the filter cloth 113 moves upward and returns to its original position. During the upward movement of the filter cloth 113, the filter cloth cleaning process execution unit 37 supplies cleaning water 43 from a cleaning water pipe 117 located below the dewatering device 104 using a filter cloth cleaning pump (not shown). By spraying this cleaning water 43 onto the filter cloth 113, the filter cloth 113 is cleaned, preventing clogging and reliably recovering the electrode catalyst precursor and other substances adhering to it. Specifically, since the wastewater during filter cloth cleaning contains the electrode catalyst precursor, it is preferable to recover all of it. Thus, by allowing the electrode catalyst precursor adhering to the filter cloth 113 to flow and recover it, the yield of the electrode catalyst precursor can be improved. In addition, for example, the recovery of catalyst precursors for the electrode can be further improved by repeatedly moving the filter cloth 113 up and down while cleaning it.

[0135] [Pressing process]

[0136] It should be noted that the pressing process can also be performed after the forward washing process S23 and / or the backwashing process S24. The pressing process is a process of further pressing and dehydrating the filter cake 40 containing the electrode catalyst precursor, and is performed by a pressing process execution unit (not shown). Figure 10 To extract in Figure 2 The figure shows a dewatering device 104 in the washing apparatus 13, illustrating a preferred embodiment in operation during the pressing process. The filter cake 40 containing the electrode catalyst precursor is further dewatered by injecting pressurized water 119 into a diaphragm 118 disposed on a filter plate 111'. Through the pressing process, the solid content concentration of the filter cake 40 containing the electrode catalyst precursor is increased, resulting in a filter cake 40 containing the electrode catalyst precursor with extremely low moisture content.

[0137] Here, if it is configured such that pressurized water 119 is released from diaphragm 118 after the pressing process is completed, the pressure caused by diaphragm 118 disappears, and the filter cloth 113 pressed by diaphragm 118 can be easily peeled off from filter cake 40, which is therefore preferred.

[0138] It should be noted that in this pressing process, a structure may also be provided with a diaphragm (not shown) on the other filter plate 111. In this case, pressurized water is also injected into the diaphragm (not shown) provided on the filter plate 111 side, thereby enabling the filter cake 40 containing the electrode catalyst precursor to be pressed and dehydrated. Even in this case, if it is configured such that the pressurized water is released from the diaphragm after the pressing process is completed, the pressure caused by the diaphragm (not shown) disappears, so the filter cloth 113 pressed by the diaphragm (not shown) can be easily peeled off from the filter cake 40, which is therefore preferable.

[0139] In the above description, a dehydration device 104 was described, which uses, for example Figure 2 The cleaning apparatus 13 shown can increase the throughput of a single unit by allowing all dehydration units 104 to operate identically, thereby improving the production efficiency of the electrode catalyst. Furthermore, the large filtration area and high-pressure-resistant structure of the dehydration unit 104 increase the processing speed. Additionally, since the entire process, from the introduction of the raw liquid to the discharge of the filter cake and the cleaning of the apparatus, can be fully automated, the time and effort required for the cleaning process can be reduced. Moreover, since resin or liner materials can be selected as the materials for the apparatus, high corrosion resistance can be achieved.

[0140] [The conductivity ρ of the filtrate]

[0141] The conductivity ρ of the filtrate obtained after the forward washing step S23 and / or the backwashing step S24 is measured according to the JIS standard test method (JIS K0522). The processing conditions, such as the forward washing time of the forward washing step S23 and the backwashing time of the backwashing step S24, are adjusted to bring the conductivity ρ to a preset value or lower. For example, if the cleaning time of the backwashing step is extended to the same extent as the cleaning time of the forward washing step, the cleaning effect is increased. "The same extent" means a difference of 0 to 15 minutes (the absolute value of the difference between the cleaning time of the forward washing step and the cleaning time of the backwashing step). Furthermore, the filtrate is the liquid discharged from the filtrate outlet after cleaning; preferably, the total filtrate discharged in this step is used.

[0142] The conductivity ρ of the filtrate obtained after the forward washing step S23 is preferably selected from a value in the range of 20 μS / cm or less. The conductivity ρ of the filtrate obtained after the backwashing step S24 is preferably selected from a value in the range of 10 μS / cm or less. If the conductivity ρ of the filtrate is 10 μS / cm or less, the concentration of chlorine (Cl) or bromine (Br) in the electrode catalyst precursor can be reduced to a level that makes it practical for use as an electrode catalyst for fuel cells.

[0143] The cleaning water 43 used in the cleaning device 13 can be pure water such as ultrapure water, but it may not be pure water. For example, it can be water with a pH of 6-8 and a conductivity ρ measured according to the JIS standard test method (JIS K0522). i Ion-exchanged water with a flow rate of less than 10 μS / cm, etc.

[0144] It should be noted that, in this embodiment, although a cleaning and filtration method using a filter press is used in the cleaning process, a conventional cleaning and filtration method using a centrifuge (not shown) or similar equipment can also be used.

[0145] (Drying device)

[0146] Figure 11 The schematic structure of the drying apparatus 14 according to the present invention is shown. The drying apparatus 14 dries the electrode catalyst precursor that has been cleaned by the cleaning apparatus 13 described above using a stirring treatment device 201 having stirring blades 204. The stirring treatment device 201, which is the drying apparatus, mainly has a hollow container body 202 in the shape of an inverted cone, a decompression mechanism 203 for depressurizing the interior of the container body 202, and stirring blades 204. The upper part of the container body 202 is covered by a cover 205 that can be detachably provided on the container body 202. A jacket 206 is provided on the peripheral wall for the flow of steam S, which is the heating medium for heating the interior of the container body 202. Support parts 210, 210 are provided on the outer surface to support the container body 202. Load sensors 212 and 212 capable of detecting weight changes are provided on the lower surfaces of the support parts 210 and 210. By installing the support parts 210 and 210 at the installation location via the load sensors 212 and 212, the container body 202 can be suspended at the installation location.

[0147] Furthermore, a stirring blade 204 is arranged inside the stirring container body 202, and a driving device 207 for the stirring blade 204 is provided on the cover 205 on the upper part of the container body 202. An opening 208 for removing the electrode catalyst precursor from the container body 202 is formed at the top of the cone at the lower end of the container body 202. A removal valve 209 is provided on this opening 208 and is configured to open by operating the removal valve 209, thereby removing the electrode catalyst precursor from the container body 202. Moreover, a supply port 211 is provided on the cover 205 on the upper part of the container body 202, and a supply valve 215 is provided on this supply port 211 and is configured to open by operating the supply valve 215, thereby supplying the electrode catalyst precursor to the container body 202.

[0148] Furthermore, a heating medium inlet 213 for injecting steam S and a heating medium outlet 214 for discharging steam S are provided on the jacket 206. A temperature indicator regulator 216 is provided on the container body 202 to monitor the temperature of the electrode catalyst precursor within the container body 202. By adjusting the amount of steam S supplied to the heating medium inlet 213 and the amount of steam S discharged from the heating medium outlet 214, the temperature of the electrode catalyst precursor within the container body 202 can be adjusted. In addition to the heating medium, a cooling medium C can also be injected into the heating medium inlet 213; and in addition to the heating medium, the cooling medium C can also be discharged from the heating medium outlet 214.

[0149] Figure 12 This is a perspective view of the stirring blade 204. The stirring blade 204 includes a rotating main shaft 222 extending through the center of the cover 205, a helical ribbon-shaped rotating blade 223 mounted at the front end of the rotating main shaft 222 and rotating together with the rotating main shaft 222, an arm 224 serving as a support for the rotating blade connecting the rotating main shaft 222 and the helical ribbon-shaped rotating blade 223, and a vortex eliminator 225 disposed above the helical ribbon-shaped rotating blade 223 on the rotating main shaft 222. The rotating main shaft 222, the helical ribbon-shaped rotating blade 223, the arm 224, and the vortex eliminator 225 are integrally formed.

[0150] Rotating spindle 222 passes through sealing unit 221 (see reference) Figure 11 The rotating main shaft 222 is assembled in the drive unit 207, and the drive unit 207 is used to rotate the rotating main shaft 222. This, in turn, causes the spiral ribbon-shaped rotating blade 223, arm 224, and vortex eliminator 225, which are integrally formed with the rotating main shaft 222, to rotate. Therefore, by rotating the rotating main shaft 222 through the drive unit 207, the rotating main shaft 222 can rotate the stirring blade 204. Furthermore, the rotating main shaft 222 is formed as a hollow tube and is circumferentially connected to the arm 224, which is also formed as a hollow tube. Furthermore, the end of the rotating spindle 222 on the drive device 207 side may be connected to a flow channel for scraping gas G. For example, it may be connected to a flow channel for nitrogen, atmospheric air, a mixed gas with nitrogen and oxygen mixed in any proportion to modulate the oxygen concentration, a mixed gas with nitrogen and air mixed in any proportion to modulate the oxygen concentration, or high-pressure air. This gas G can be injected into the rotating spindle 222, for example, through the slow oxidation process execution unit 54 or the removal process execution unit 55 described later.

[0151] If reference Figure 11The drive unit 207 uses a geared motor or the like and adjusts the rotation speed to a predetermined value, thereby rotating the stirring blade 204. Furthermore, the drive unit 207 has a position detection device (not shown) that detects the rotation and position of the stirring blade 204. The sealing unit 221 is equipped with, for example, a dry seal and a mechanical seal, so that it can handle situations where there is a high vacuum or high pressure inside the container body 202.

[0152] The helical ribbon-shaped rotating blade 223 is formed in a spiral shape, maintaining a small gap along the inner wall surface of the conical container body 202 when the stirring blade 204 is disposed within the container body 202. By rotating the helical ribbon-shaped rotating blade 223 within the container body 202, the catalyst precursor for the electrode rises along the inner wall surface of the container body 202. Furthermore, the width of the ribbon-shaped rotating blade 223 increases towards the top, thereby achieving a certain ratio of powder delivery in each cross-section of the container body 202 in the vertical direction. It should be noted that, in this embodiment, as... Figure 12 As shown, although the helical ribbon rotor 223 uses a single ribbon, it can also use a double ribbon.

[0153] Reference Figure 12 Arm 224 supports the helical ribbon-shaped rotating blade 223 and reliably fixes the helical ribbon-shaped rotating blade 223 to the rotating main shaft 222. Furthermore, a scraping gas ejection hole 226 is provided on the lower side of the front end of each arm 224. Once gas G is injected into the rotating main shaft 222 from the aforementioned gas G flow channel, the gas G will pass through the rotating main shaft 222 and each arm 224, and then be ejected from each gas ejection hole 226. Therefore, during the removal process S35 described later, retention of the electrode catalyst precursor can be prevented.

[0154] The eddy current eliminator 225, by rotating within the container body 202, guides the electrode catalyst precursor rising along the inner wall surface of the container body 202 to the center of the container body 202. Therefore, the circulating flow of the electrode catalyst precursor is guided downwards in the center of the container body 202, preventing the grading effect caused by turbidity flow on the layer surface during free fall.

[0155] It should be noted that, in Figure 12 In this embodiment, the eddy current eliminator 225 is configured such that a gap is left between it and the inner surface of the cover 205. However, in this invention, the eddy current eliminator 225 may also be integrally configured to contact the inner surface of the cover 205. Even in this case, it is possible to prevent the aforementioned grading effect.

[0156] return Figure 11The following describes the pressure reduction mechanism 203. 231 is a bag filter, and it is installed at the vent 232 of the cover 205. Liquid or gas evaporated from the electrode catalyst precursor within the container body 202 is discharged through this bag filter 231. 233 is a condenser, used to condense the liquid flowing from the bag filter 231. The condenser 233 and the vent 232 of the cover 205 are connected via the bag filter 231 and a connecting pipe 235. Furthermore, 234 is a vacuum pump connected to the condenser 233 via a suction pipe 236. By driving this vacuum pump 234, liquid or gas evaporated from the electrode catalyst precursor can flow from the container body 202 to the bag filter 231 and the condenser 233. Additionally, a pressure gauge 237 is installed on the connecting pipe 235, allowing adjustment of the pressure within the container body 202 during pressure reduction drying. Based on the adjustment signal from the pressure indicator regulator 237, the regulating valve 238, located on the suction pipe 236, is adjusted, thereby regulating the vacuum level sucked by the vacuum pump 234. It should be noted that the gas and vapor flowing from the bag filter 231 via the connecting pipe 235 are condensed by the condenser 233, where easily condensable components are separated from the gas as condensate. The separated gas is then drawn into the vacuum pump 234 via the suction pipe 236 and exhausted from the vacuum pump 234. It should also be noted that a blow nozzle (not shown) can be provided at the lower part of the container body 202, through which inactive gas or air is injected, thereby returning the container body 202 from a depressurized state to an atmospheric pressure state.

[0157] like Figure 1 block diagram and Figure 20 As shown in the flowchart, the drying apparatus 14 includes an introduction process execution unit 51, a drying process execution unit 52, a cooling process execution unit 53, a slow oxidation process execution unit 54, and a removal process execution unit 55, which respectively perform the introduction process S31, the drying process S32, the cooling process S33, the slow oxidation process S34 for slow oxidation treatment of the cooled electrode catalyst precursor, and the removal process S35 for removing the slowly oxidized electrode catalyst precursor. The following describes each process S31 to S35.

[0158] Example

[0159] [Import Process]

[0160] The introduction process S31 is the process of introducing the cleaned electrode into the drying apparatus 14 using a catalyst precursor, and it is performed by the introduction process execution unit 51. (See reference here.) Figure 13ATo explain, the supply valve 215 of the stirring and processing device 201 in the inlet process unit 51 is opened, thereby introducing the electrode catalyst precursor with a specified moisture content from the supply port 211 into the container body 202. The moisture content of the electrode catalyst precursor is preferably determined beforehand. The method for introducing the electrode catalyst precursor can be manual operation using a funnel or similar device, or as described above. Figure 13A As shown, the catalyst precursor for the electrode is introduced directly from a pipeline or belt conveyor without manual operation. Here, the weight of the introduced catalyst precursor is measured using load sensors 212, 212. It should be noted that a preheating process can be performed before this introduction step S31, where steam S is injected into the jacket 206 to preheat the container body 202 to a predetermined temperature. Afterwards, the introduction step execution unit 51 operates the supply valve 215 to close it, thereby sealing the container body 202 and ending the introduction step S31.

[0161] [Drying Process]

[0162] The drying process S32 is a process of drying the electrode catalyst precursor introduced into the container body 202 (a process of performing so-called vacuum drying), and is performed by the drying process execution unit 52. Here, Figure 11 Equal and Figure 13B Referring to the description, the drying process execution unit 52 drives the drive device 207, which in turn rotates the stirring blade 204. Simultaneously, it drives the vacuum pump 234 to exhaust and depressurize the contents of the container body 202. The operating pressure is adjusted to a predetermined pressure by the pressure indicator regulator 237, thereby stirring and mixing the electrode catalyst precursor. The rotation speed of the stirring blade 204 is preferably 40-80 revolutions per minute, and the operating pressure is preferably 5-20 kPa (gauge pressure). Furthermore, the drying process execution unit 52 injects steam S from the heating medium injection port 213 into the jacket 206 via the temperature indicator regulator 216. The steam S conducts heat to heat the container body 202, thereby adjusting the electrode catalyst precursor inside the container body 202 to a predetermined temperature (drying temperature) and drying it. In addition, the heat generated by the stirring of the stirring blade 204 contributes to the drying of the electrode catalyst precursor. The drying temperature is preferably selected from the range of 50-150°C. It should be noted that, in order to observe the degree of temperature change by measuring the temperature of the catalyst precursor for the electrode and adjust the drying time, the operating pressure and heating temperature can also be changed during the drying process.

[0163] The circulation flow of the electrode catalyst precursor within the container body 202 in the drying process S32 will be described in more detail here. The electrode catalyst precursor rises along the surface of the inner wall of the container body 202 due to the rotation of the stirring blades 204. Thereafter, once the electrode catalyst precursor is gathered at the center of the container body 202 by the vortex eliminator 225 positioned above the helical ribbon-shaped rotating blades 223, it immediately descends from the center and mixes into the layer, thus completing the circulation.

[0164] Additionally, the vapor or gas evaporated from the electrode catalyst precursor is drawn in by the vacuum pump 234 and filtered through the bag filter 231 to collect dust. Then, it flows to the condenser 233 via the connecting pipe 235, where it is cooled and liquefied by the condenser 233. The condensate is recovered, and the gas is discharged by the vacuum pump 234. Thus, the weight of the electrode catalyst precursor changes as vapor or gas evaporates from it. The weight of the electrode catalyst precursor in the container body 202 at this time is measured by the load sensors 212, 212, and the current moisture content of the electrode catalyst precursor is calculated from the initial weight and moisture content of the precursor, as well as its current weight. The drying step S32 ends when the moisture content of the electrode catalyst precursor in the container body 202 drops below a specified moisture content. The specified moisture content is preferably 3 wt%. Hereinafter, the moisture content value is expressed on a wet basis.

[0165] It should be noted that, in the case of this invention, a structure without the load sensor 212 may also be used. In such a case, the same drying conditions (weight of the electrode catalyst precursor added to the container body 202, drying conditions) as in the drying process S32 can be used, and the weight change of the electrode catalyst precursor in the container body 202 can be known in advance by conducting a preliminary test. Moreover, based on the results of the preliminary test, the weight change of the electrode catalyst precursor in the container body 202 can be easily known by monitoring the elapsed time from the start of drying.

[0166] [Cooling Process]

[0167] Cooling step S33 is a process for cooling the electrode catalyst precursor that has been dried within the container body 202, and is performed by cooling step execution unit 53. Here, it will be... Figure 11 Equal and Figure 13CReferring to the description, the cooling process execution unit 53 discharges the steam S in the jacket 206 from the heating medium outlet 214 through the temperature indicator regulator 216. Here, the cooling process execution unit 53 continues to drive the drive device 207 and the vacuum pump 234, causing the stirring blade 204 to rotate, while simultaneously venting and depressurizing the container body 202, continuing the stirring and mixing of the electrode catalyst precursor. The rotational speed of the stirring blade 204 is preferably 40 to 80 revolutions per minute, and the operating pressure during depressurization is preferably atmospheric pressure. Furthermore, the cooling process execution unit 53 injects the cooling medium C into the jacket 206 from the heating medium outlet 214 through the temperature indicator regulator 216, and cools the container body 202 through heat transfer via the cooling medium, thereby cooling the electrode catalyst precursor inside the container body 202 to a predetermined temperature. The temperature of the cooling medium C is preferably 10 to 30°C, and the predetermined temperature is below 40°C, preferably a value selected from the range of 10 to 40°C. The cooling process execution unit 53 terminates the cooling process when the temperature indicator regulator 216 detects that the catalyst precursor for the electrode has reached the specified temperature.

[0168] [Slow oxidation process]

[0169] The slow oxidation process S34 is a process of slowly oxidizing the electrode catalyst precursor that has been cooled inside the container body 202, and is performed by the slow oxidation process execution unit 54. The slow oxidation process execution unit 54 discharges the cooling medium C from the heating medium injection port 213 inside the jacket 206, stops the drive device 207 and the vacuum pump 234, operates the supply valve 215, and gradually restores the pressure inside the container body 202 to atmospheric pressure, thereby slowly oxidizing the dried electrode catalyst precursor. It should be noted that when the scraping gas G is high-pressure air, the slow oxidation process execution unit 54 can also inject high-pressure air from the flow channel of the scraping gas G into the rotating spindle 222, and gradually restore the pressure inside the container body 202 to atmospheric pressure by ejecting high-pressure air from each gas ejection port 226. Alternatively, when the blowing nozzle is located at the lower part of the container body 202, the slow oxidation process execution unit 54 can also gradually restore the pressure inside the container body 202 to atmospheric pressure through this blowing nozzle. The slow oxidation step ends when the slow oxidation treatment of the electrode catalyst precursor in the container body 202 is completed.

[0170] It should be noted that in the slow oxidation process S34, as the pressure inside the container body 202 gradually returns to normal pressure, and the container body 202 eventually returns to an air atmosphere at normal pressure, a mixed gas with nitrogen and oxygen in any proportion is ejected from each gas ejection hole 226, thereby modulating the oxygen concentration. Alternatively, a mixed gas with nitrogen and air in any proportion is ejected, thereby modulating the oxygen concentration. Preferably, the oxygen concentration inside the container body 202 is controlled within the numerical range determined in a pre-experimental manner in a way that does not cause the electrode to ignite with the catalyst precursor in this process, while increasing over time, eventually reaching the same oxygen concentration as air.

[0171] [Removal Process]

[0172] The removal process S35 is the process of removing the cooled electrode catalyst precursor from the container body 202, and is performed by the removal process execution unit 55. Here... Figure 11 Equal and Figure 13D Referring to the description, the removal process execution unit 55 opens the removal valve 209, thereby removing the electrode catalyst precursor from the container body 202 through the opening 208. Because the internal structure of the container body 202 of the stirring processing device 201 is simple, residual powder of the electrode catalyst precursor can be reduced during the removal process S35. Furthermore, at this time, the removal process execution unit 55 performs a scraping process by injecting gas G into the rotating main shaft 222 from the scraping gas G flow channel and spraying gas G downwards from each gas ejection hole 226, blowing away the electrode catalyst precursor adhering to the inner wall of the container body 202 or the stirring blades 204, thus improving the recovery rate of the electrode catalyst precursor. The removal process ends when all the electrode catalyst precursor in the container body 202 has been removed.

[0173] <Catalysts for Electrodes>

[0174] The structure of the electrode catalyst manufactured in this embodiment is not particularly limited, as long as it has a structure in which noble metal catalyst particles are supported on a conductive support (conductive carbon support, conductive metal oxide support, etc.). For example, it can also be a so-called Pt catalyst, a Pt alloy catalyst (PtCo catalyst, PtNi catalyst, etc.), or a so-called core-shell catalyst with a core-shell structure.

[0175] For example, core-shell catalysts with palladium as the constituent element of the core 4 and platinum as the constituent element of the shell 5 often use materials containing chlorine (Cl) such as chloride salts of platinum (Pt) and chloride salts of palladium (Pd) as raw materials. According to the electrode catalyst manufacturing system and method of this embodiment, electrode catalysts with reduced chlorine (Cl) content can be manufactured.

[0176] Referring to the accompanying drawings, an example of the structure of a catalyst for an electrode will be described in more detail. Figure 14 As shown, the electrode catalyst 1 with a core-shell structure includes a support 2 and catalyst particles 3 supported on the support 2. The catalyst particles 3 include a core 4 and a shell 5 formed to cover at least a portion of the core 4. The catalyst particles 3 have a so-called core-shell structure including the core 4 and the shell 5 formed on the core 4.

[0177] That is, the electrode catalyst 1 has catalyst particles 3 supported on the support 2. The catalyst particles 3 have a structure in which a core 4 serves as the core and a shell 5 covers the surface of the core 4. In addition, the constituent elements (chemical composition) of the core 4 and the constituent elements (chemical composition) of the shell 5 are different.

[0178] exist Figure 15 In this example, if we further illustrate a specific example of the core-shell structure, the electrode catalyst 1A has catalyst particles 3a consisting of a core 4, a shell portion 5a covering a portion of the surface of the core 4, and a shell portion 5b covering the remaining portion of the surface of the core 4. Furthermore, in Figure 16 In the electrode catalyst 1B, there are catalyst particles 3 consisting of a core 4 and a shell 5 covering approximately the entire surface of the core 4, and the shell 5 has a double-layer structure having a first shell 6 and a second shell 7. Furthermore, in Figure 17 In the catalyst 1C for the electrode, there is a catalyst particle 3a consisting of a core 4, a shell 5a covering a portion of the surface of the core 4, and a shell 5b covering the remaining portion of the surface of the core 4. The shell 5a has a double-layer structure having a first shell 6a and a second shell 7a, and the shell 5b has a double-layer structure having a first shell 6b and a second shell 7b.

[0179] In this embodiment, chlorine (Cl) species refers to chemical species that contain chlorine as a constituent element. Specifically, chlorine-containing chemical species include chlorine atoms (Cl), chlorine molecules (Cl2), chloride ions (Cl-), chlorine radicals (Cl·), polyatomic chloride ions, and chlorine compounds (such as X-Cl, where X is an anti-charge ion).

[0180] In this embodiment, bromine (Br) species refers to chemical species that contain bromine as a constituent element. Specifically, bromine-containing chemical species include bromine atoms (Br), bromine molecules (Br2), bromide ions (Br-), bromine radicals (Br·), polyatomic bromide ions, and bromine compounds (such as X-Br, where X is an anti-charge ion).

[0181] <Method for manufacturing catalysts for electrodes>

[0182] like Figure 18As shown, the method for manufacturing an electrode catalyst according to this embodiment includes: an electrode catalyst precursor manufacturing step S1, which manufactures an electrode catalyst precursor as a raw material for the electrode catalyst; a cleaning step S2, which cleans the liquid 30 containing the electrode catalyst precursor manufactured in the electrode catalyst precursor manufacturing step S1 by using a filter press; and a drying step S3, which dries the electrode catalyst precursor cleaned in the cleaning step S2 by using a stirring treatment apparatus 201 equipped with stirring blades 204 having a spiral ribbon-shaped rotating blade 223. Each of steps S1, S2, and S3 can be performed by the electrode catalyst precursor manufacturing apparatus 12 of the electrode catalyst manufacturing system 10 described above, the filter press as the cleaning apparatus 13, and the stirring treatment apparatus 201 as the drying apparatus 14.

[0183] like Figure 19 As shown, the cleaning step S2 includes a plate closing process S21, a pressing process S22, a forward washing process S23, a backwashing process S24, a plate opening process S25, a filter cake stripping process S26, and a filter cloth cleaning process S27. In the cleaning step S2, the liquid 30 containing the electrode catalyst precursor produced in the electrode catalyst precursor manufacturing step S1 is washed, filtered, and dehydrated to obtain a cleaned electrode catalyst precursor 41. Alternatively, a pressing process can be performed after the forward washing process S23 and / or after the backwashing process S24. The structures of each process S21 to S27 and the pressing process are the same as those described in the <Electrode Catalyst Manufacturing System> (cleaning apparatus) above.

[0184] like Figure 20 As shown, the drying step S3 includes an introduction step S31, a drying step S32, a cooling step S33, a slow oxidation step S34, and a removal step S35. In the drying step S3, the electrode catalyst precursor cleaned in the cleaning step S2 is dried to obtain the dried electrode catalyst 1. The structures of each step S31 to S35 are the same as those described in the <Electrode Catalyst Manufacturing System> (drying apparatus) above.

[0185] The embodiments described herein are examples of implementations of the present invention, but should not be construed as limiting the scope of the invention.

[0186] <Preparation of Electrode Catalyst Precursors (Reaction Process, Preparation Steps for Electrode Catalyst Precursors)>

[0187] (Manufacturing Example 1)

[0188] [Preparation of liquid (stock solution) containing electrode catalyst precursor]

[0189] As the electrode catalyst, a Pt particle-supported carbon catalyst (hereinafter referred to as "Pt / C catalyst"). Manufactured by NECHEMCAT Corporation, with a Pt loading of 50 wt%, trade name: "SA50BK"). First, a liquid containing its precursor was prepared.

[0190] As the carrier for this precursor, a commercially available conductive hollow carbon carrier (manufactured by Lion Corporation, trade name "CARBON ECP") (registered trademark) (Ketjen black.EC300J) with a specific surface area of ​​750-800 m² was used. 2 / g}.

[0191] The support and water-soluble Pt salt were dispersed in water. Next, a water-soluble reducing agent was added to the dispersion containing the support and water-soluble Pt salt, thereby carrying out a reduction reaction of the Pt component at a specified temperature. Thus, a liquid containing an electrode catalyst precursor used in this embodiment was prepared.

[0192] The liquid containing the electrode catalyst precursor obtained as described above is not dried, but dispersed in the reactor and used as the stock solution for treatment with a cleaning device.

[0193] <Preparation of Catalysts for Electrodes>

[0194] (Example 1)

[0195] [Processing by a cleaning device (cleaning steps)]

[0196] The liquid containing the electrode catalyst precursor obtained in Manufacturing Example 1 was introduced into a cleaning apparatus for cleaning. The processing time of each step in the cleaning apparatus is shown in Table 1. First, a pressing process was performed for 20 minutes. The thickness of the filter cake containing the electrode catalyst precursor in the pressing process was 5 to 10 mm.

[0197] The thickness of the filter cake is a range determined in advance through preliminary experiments, taking into account the required degree and time of cleaning relative to the catalyst precursor used for the electrode.

[0198] Next, a forward washing process was performed. In this process, the filtrate was first treated with room temperature (23°C) washing water for 24 minutes. When the conductivity ρ of the filtrate fell below 40 μS / cm, the process was switched to heated water (70°C) for 50 minutes. Following the forward washing process, a 5-minute pressing process was performed. Then, a backwashing process was conducted. In this backwashing process, the filtrate was treated with hot water (70°C) for 73 minutes. The total washing process lasted approximately 2.9 hours.

[0199] Ion-exchanged water was used as the cleaning water. The conductivity ρ of the ion-exchanged water used at room temperature (23℃) is... i The conductivity ρ is 7.70 μS / cm, and the conductivity ρ at heating (70℃) is... i It is 4.6 μS / cm.

[0200] [Processing via a drying unit (drying step)]

[0201] The filter cake containing the electrode catalyst precursor obtained after being processed by the cleaning device was introduced into the stirring processing device 201, which is a drying device, and the drying step S3 was carried out.

[0202] It should be noted that in this Example 1, since the filter cake containing the electrode catalyst precursor is dried using a stirring processing device 201 with a stirring mechanism, it is not necessary to crush the filter cake containing the electrode catalyst precursor (coarse crushing of the filter cake before it is introduced into the vacuum drying cabinet) as in Comparative Example 1 described later. That is, the crushing process in Comparative Example 1 described later is not required.

[0203] Table 2 shows the processing time for each step involved in the stirring and processing apparatus 201.

[0204] In the introduction process S31, the capacity of the stirring device 201 is selected based on the powder surface height inside the container body 202 of the stirring device 201 when 52kg of filter cake is loaded. A stirring device 201 with an effective capacity of 100L for the container body 202 and a single-strip spiral blade 223 is adopted.

[0205] First, in the introduction process S31, 52 kg of filter cake with a moisture content of about 82% is loaded into the container body 202.

[0206] Then, the drying process S32, cooling process S33, and slow oxidation process S34 are performed sequentially, and the filter cake is removed in the removal process S35. The time required to obtain an electrode catalyst with a water content of less than 3 wt% is measured.

[0207] In addition, in order to confirm whether the "friction" caused by stirring and drying has an impact on the product, in the cooling process S33, while the stirring blade 204 is rotating, the cooling medium C is injected into the jacket 206 from the heating medium outlet 214, and a stirring test of the electrode catalyst precursor is carried out while cooling.

[0208] (Comparative Example 1)

[0209] [Processing by a cleaning device (cleaning steps)]

[0210] The liquid containing the electrode catalyst precursor obtained in Manufacturing Example 1 was introduced into a cleaning apparatus for cleaning. The processing time of each step in the cleaning apparatus is shown in Table 1. First, a pressing process was performed for 40 minutes. The thickness of the filter cake containing the electrode catalyst precursor in the pressing process was 11 to 15 mm.

[0211] The thickness of the filter cake deviates from the range of thicknesses determined in advance through preliminary experiments, taking into account the required degree and time of cleaning relative to the catalyst precursors used in the electrode.

[0212] Next, a forward washing process was performed. In this process, the filtrate was first treated with room temperature (23°C) washing water for 33 minutes. When the conductivity ρ of the filtrate fell below 40 μS / cm, the process was switched to heated water (70°C) and continued for 60 minutes. Following the forward washing, a 5-minute pressing process was performed. Then, a backwashing process was initiated. However, since the conductivity ρ of the filtrate did not change from its value at the end of the forward washing, this process was interrupted after a 36-minute backwash, resulting in a total washing time of approximately 2.9 hours.

[0213] Ion-exchanged water was used as the cleaning water. The conductivity ρ of the ion-exchanged water used at room temperature (23℃) is... i The conductivity ρ is 7.70 μS / cm, and the conductivity ρ at heating (70℃) is... i It is 4.6 μS / cm.

[0214] [Processing via a drying unit (drying step)]

[0215] The filter cake containing electrode catalyst precursors, obtained after being processed by a cleaning device, was dried using a dedicated crusher, vacuum drying cabinet, and hammer mill.

[0216] First, in the crushing process of the filter cake using a special crusher, 52 kg of electrode catalyst precursor with a moisture content of about 80-82% was obtained.

[0217] In this crushing process, the filter cake is removed from the washing device and crushed (coarse crushing of the filter cake before it is introduced into the vacuum drying cabinet) containing the electrode catalyst precursor. Unlike the stirring treatment device 201 of Example 1, since the vacuum drying cabinet used in Comparative Example 1 is not equipped with a stirring mechanism, it is necessary to use a crusher to coarsely crush the filter cake before it is introduced into the vacuum drying cabinet, distribute the crushed filter cake roughly equally, and arrange it on the rack.

[0218] In the subsequent introduction process, the electrode catalyst precursor was packaged into 20 trays, each 600 mm wide, 780 mm long, and 20 mm high, for filter cake preparation. A drying process was then performed, in which the trays containing the electrode catalyst precursor were placed in a vacuum drying cabinet, the door was closed, and the electrode catalyst precursor was dried under reduced pressure. A cooling process was also performed, in which the electrode catalyst precursor was cooled under reduced pressure.

[0219] After the cooling process, the door is slowly opened to carry out a slow oxidation process. In the subsequent removal process, the tray is taken out of the vacuum drying cabinet, and the electrode catalyst precursor is taken out from the tray.

[0220] Then, a pulverizing process was carried out on the extracted electrode catalyst precursor using a hammer mill, and the time required to obtain an electrode catalyst with a water content of less than 3 wt% was determined.

[0221] Unlike the stirring apparatus 201 in Example 1, since the vacuum drying cabinet used in Comparative Example 1 does not have a stirring mechanism, a hammer mill is required to crush the powder blocks of the electrode catalyst precursor. Furthermore, before crushing with the hammer mill, the powder blocks of the electrode catalyst precursor need to be removed from the vacuum drying cabinet.

[0222] Table 1

[0223]

[0224] <Evaluation Results>

[0225] As shown in Table 1, in Example 1, the conductivity ρ of the filtrate at the end of the forward washing step was 15.9 μS / cm, while the conductivity ρ of the filtrate at the end of the backwashing step decreased to 9.7 μS / cm. Within a washing process time of less than 3 hours, the conductivity ρ of the filtrate was reduced to below 10 μS / cm. On the other hand, in Comparative Example 1, although the conductivity ρ of the filtrate at the end of the forward washing step was reduced to 19.3 μS / cm, it did not decrease from 19.3 μS / cm at all even after a backwashing step.

[0226] Table 2

[0227]

[0228] <Evaluation Results>

[0229] As shown in Table 2, in Example 1, the electrode catalyst precursor does not need to be packaged in the introduction process S31. Instead, the electrode catalyst precursor is simply loaded into the container body 202. Therefore, the 2 hours required in Comparative Example 1 can be shortened to 0.4 hours.

[0230] In addition, in Example 1, the drying speed is increased compared to a vacuum drying cabinet due to the high mixing capacity and heat transfer from the jacket 206 in the drying process S32 and cooling process S33, so the 24 hours required in Comparative Example 1 can be shortened to 3.1 hours.

[0231] Here, the obtained electrode catalyst is no less effective than that of Comparative Example 1, confirming that the "friction" caused by stirring and drying has almost no impact on product quality. Furthermore, in Example 1, no reduction in time was observed in the slow oxidation step S34 and the removal step S35 compared to Comparative Example 1, but the crushing and pulverizing steps can be omitted in Example 1.

[0232] (Comparative Example 2)

[0233] [Processing by a cleaning device (cleaning steps)]

[0234] The liquid containing the electrode catalyst precursor obtained in Manufacturing Example 1 was introduced into a centrifuge for washing. The washing process was repeated until the conductivity ρ of the filtrate, as measured by the JIS standard test method (JIS K0522), was below 10 μS / cm. The obtained electrode catalyst precursor was dispersed in ultrapure water to prepare a dispersion, which was then filtered. The filtered material was dried using a drying apparatus at 70°C in air for 24 hours to obtain the electrode catalyst.

[0235] The processing times of the cleaning process (cleaning step) in Example 1 and Comparative Example 2 were compared, and the results are shown in Table 3. It should be noted that in Table 2, the processing time from raw material feeding to solid-liquid separation and the time required for cleaning and dewatering the filter cake are shown separately.

[0236] Table 3

[0237] Raw material feeding ~ solid-liquid separation Filter cake washing and dehydration total Example 1 0.33 hours 2.9 hours 3.3 hours Comparative Example 2 Approximately 1 hour 15-19 hours 16-20 hours

[0238] <Evaluation Results>

[0239] In Comparative Example 2, where a centrifuge was used for cleaning as before, it took 15 to 19 hours to reduce the conductivity ρ of the filtrate to below 10 μS / cm after three trials.

[0240] Therefore, as understood when comparing Example 1 with Comparative Examples 1 and 2, the manufacturing system and method for the electrode catalyst according to this embodiment can significantly reduce the time required for processing (cleaning step) using a cleaning device to less than 1 / 5 compared to conventional processing using a centrifuge. Furthermore, in the cleaning device of this embodiment, since the filter cake containing the electrode catalyst precursor is automatically peeled off, the operator's operation of scraping the electrode catalyst precursor can be eliminated, thereby significantly reducing manual labor.

[0241] Furthermore, as understood when comparing Example 1 with Comparative Example 1, the manufacturing system and method for the electrode catalyst according to this embodiment can significantly reduce the time required for processing in the drying apparatus 14 (drying step S3) to approximately 1 / 5 to approximately 1 / 6. Moreover, as the stirring processing apparatus 201 relating to the drying apparatus 14 of this embodiment, since the drying step S32, cooling step S33, slow oxidation step S34, and removal step S35 can be performed entirely automatically, manual labor can be greatly reduced, thereby providing a manufacturing method and system for the electrode catalyst that requires minimal manual operation.

[0242] <Electrode Catalyst Manufacturing System>

[0243] Figure 21 This is a schematic block diagram illustrating the manufacturing system for the electrode catalyst according to the second embodiment. The electrode catalyst manufacturing system 150, in addition to the electrode catalyst precursor manufacturing apparatus 12, cleaning apparatus 13, and drying apparatus 14 described in the first embodiment, also includes an analysis apparatus 151 for analyzing the physical properties of the dried electrode catalyst 1 and the WET product prepared from the catalyst filter cake, and a reactor 152 for re-slurrying by mixing ion-exchange water into the dried electrode catalyst 1.

[0244] Previously, concerns about the ignition and loss of powdered electrode catalysts during packaging and weighing by customers have been a problem that needed to be addressed. Regarding countermeasures against ignition and loss of electrode catalysts and future packaging and delivery methods, it is believed that supplying WET (water-based emulsion) products, where the electrode catalyst powder is moistened with pure water, can address this issue, and increased demand is anticipated. However, if the electrode catalyst to water ratio is, for example, 1:4 by weight, the WET product will not form a solid but will remain liquid. Since electrode catalysts are expensive, recycling is necessary as much as possible; however, if the WET product is dried directly while still adhering to the device or container holding the electrode catalyst, the electrode catalyst will adhere to the inner wall of the container. Furthermore, a method has been proposed in which the ratio of electrode catalyst to water is adjusted to a desired weight ratio in the drying step S32 of the first embodiment to form a WET product and then removed. However, in this case, the WET product, which has not undergone the slow oxidation step S34, may not be able to achieve a sufficiently stable oxidation state on the surface of the catalyst particles of the electrode catalyst in the atmosphere. Consequently, it may result in electrode catalysts with different initial activities for the hydrogenation reaction and the oxygen reduction reaction. Additionally, in this case, since only the electrode catalyst precursor is washed and filtered in the washing step S2, the uniformity of the moisture content in the WET product may be uneven. For these reasons, supplying WET products presents difficulties in terms of handleability and recyclability for both manufacturers and suppliers to customers.

[0245] Therefore, in this embodiment, the cleaned electrode catalyst precursor is dried to ensure that the oxidation state of the catalyst particles on the surface of the electrode catalyst is sufficiently stable in the atmosphere. Furthermore, ion-exchanged water is mixed into the dried electrode catalyst 1, and after the water content of the slurry containing the electrode catalyst is made uniform, it is dried to a level suitable for forming a solid (granular or cake-like) state. In this way, the moisture content of the WET product is adjusted to the target range, thereby preparing multiple solid catalyst cakes. By supplying the WET product in a desired weight ratio, the risk of ignition and dissipation of the powdered catalyst can be reliably prevented. Furthermore, this improves processability and recyclability for both the manufacturer and the supplier to the customer. It should be noted that for solid catalyst cakes, during the catalyst synthesis process, the surface of the catalyst support is subjected to various chemical effects from the reagents used in the synthesis, products generated in each synthesis reaction, byproducts, and impurities. As a result, the types, total amount, and abundance of functional groups on the surface of the catalyst support vary. Therefore, the affinity (wetting property) of the catalyst to water varies depending on the type of catalyst (type of support) and the type of synthetic reaction process used. Thus, it is possible to form a processable... ·The water content (range) of the solid with excellent recyclability is the water content obtained by conducting experiments on each catalyst in advance.

[0246] (Analytical apparatus)

[0247] The analytical apparatus 151 performs a physical property analysis on the electrode catalyst 1 obtained through the drying step S3 of the first embodiment. The analytical apparatus 151 includes a first physical property analysis execution unit 153 that performs a first physical property analysis step S36 on the electrode catalyst 1 extracted in the extraction step S35 of the first embodiment. In this first physical property analysis step S36, it is preferable to analyze at least the catalyst loading, moisture content (wt%), and catalyst particle size of the electrode catalyst 1. It should be noted that in this embodiment, a method is used to extract a portion of the powder of the electrode catalyst 1 extracted in the extraction step S35 and perform physical property analysis using the analytical apparatus 151, but other analytical methods may also be used.

[0248] (reactor)

[0249] After the first property analysis step S36, reactor 152 re-slurries the electrode catalyst 1 dried in the aforementioned drying apparatus 14. In this embodiment, using reactor 152 to re-slurry the electrode catalyst 1, although requiring an additional piece of equipment, allows for faster and more reliable re-slurrying of the electrode catalyst 1. Reactor 152 includes a re-slurrying step execution unit 154 for performing a re-slurrying step S40, which re-slurries the electrode catalyst 1 removed in the removal step S35. As a method for performing re-slurrying in the re-slurrying step S40, a reactor equipped with a stirring device can be used, for example, a re-slurrying method using a vessel with a stirrer.

[0250] like Figure 21 block diagram and Figure 22 As shown in the flowchart, the re-slurrying step execution unit 154 includes an introduction process execution unit 156, a mixing process execution unit 157, and a removal process execution unit 158, each responsible for executing the introduction process S41, the mixing process S42, and the removal process S43 respectively. In this embodiment, in order to maintain the oxidation state of the catalyst particles on the surface of the electrode catalyst in a stable state in the atmosphere, each of the processes S41 to S43 is executed at room temperature, atmospheric pressure, and in the atmosphere, without using a special gas atmosphere such as nitrogen. Each of the processes S41 to S43 will be described below.

[0251] [Import Process]

[0252] The introduction process S41 is the process of introducing the electrode catalyst 1 dried by the drying device 14 and the mixed ion-exchange water into the reactor 152, and it is performed by the introduction process execution unit 156. The method of introducing the electrode catalyst 1 and ion-exchange water is the same as that of the introduction process S31. It can be carried out manually using a funnel or the like, or the pipeline or belt conveyor for transferring the electrode catalyst 1 and ion-exchange water can be set in the reactor 152, and the introduction can be carried out directly without manual operation.

[0253] For ion-exchange water, pure water can be used, but "ultrapure water" is preferred. "Ultrapure water" is defined by the following formula:

[0254] R = 1 / ρ…(1)

[0255] The resistivity R (the reciprocal of the conductivity measured by the JIS standard test method (JIS K0552)) is 3.0 MΩ·cm or higher. It should be noted that in the above formula (1), R represents resistivity and ρ represents conductivity measured by the JIS standard test method (JIS K0552). In addition, "ultrapure water" is preferably clean water with a quality equivalent to "A3" or higher as specified in JIS K0557 "Water for Water Use and Drainage Tests", but there is no particular limitation as long as the water has a conductivity that satisfies the relationship expressed by formula (1). For example, as this "ultrapure water", ultrapure water produced using ultrapure water production equipment of "Milli Q series" (manufactured by Merck Co., Ltd., Japan) or "Elix UV series" (manufactured by Millipore Co., Ltd., Japan) can also be used. It should be noted that ion-exchanged water does not necessarily have to be pure water. For example, ion-exchanged water with a pH of 6-8 and a conductivity ρi of less than 10 μS / cm as measured by the JIS standard test method (JIS K0522) can also be used.

[0256] In the introduction step S41, the preferred weight ratio of the electrode catalyst 1 to the ion-exchange water is one in which the mixture of electrode catalyst 1 and ion-exchange water is in a liquid slurry state. For example, the optimal ratio is experimentally determined based on the type of catalyst, within a weight ratio of 1:2 to 1:3.5 for electrode catalyst to ion-exchange water. In this embodiment, the amount of ion-exchange water to be introduced is calculated and determined based on the results of the physical property analysis of the electrode catalyst 1, such as the catalyst loading or water content, and the amount of electrode catalyst 1 introduced. It should be noted that the amount of electrode catalyst 1 introduced can be measured manually, or the weight of the electrode catalyst 1 can be measured by load sensors 212, 212 at the beginning and end of the removal step S35 in the first embodiment, and the amount of electrode catalyst 1 can be calculated using the results.

[0257] [Mixed Steps]

[0258] Mixing step S42 is a process of mixing the introduced electrode catalyst 1 and ion-exchange water in reactor 152, and is performed by mixing step execution unit 157. Mixing step execution unit 157 drives the stirring device of reactor 152 to stir and mix the electrode catalyst 1 and ion-exchange water at room temperature and atmospheric pressure. In this embodiment, since the mixture of electrode catalyst 1 and ion-exchange water is in a slurry-like ratio, there is no risk of the electrode catalyst 1 igniting or disappearing during mixing, even at room temperature and atmospheric pressure. Furthermore, the mixture can be stirred and mixed more uniformly. The electrode catalyst 1 and ion-exchange water become homogeneous through mixing, and mixing step S42 ends when a slurry 159 containing the electrode catalyst is prepared. It should be noted that the driving time and rotation speed of the stirring device vary depending on the capacity and type of reactor 152, the amount of electrode catalyst 1 and ion-exchange water introduced, etc., and will not be described in detail here.

[0259] [Removal Process]

[0260] The removal process S43 is the process of removing the slurry 159 containing the electrode catalyst prepared in the reactor 152, and is performed by the removal process execution unit 158. Then, the removed slurry 159 containing the electrode catalyst is reintroduced into the drying device 14. Therefore, when the slurry 159 is manually introduced into the drying device 14, it can also be temporarily removed and placed in other containers, etc. Alternatively, when it is directly introduced into the drying device 14 without manual operation, a pipe or the like can be connected to the drying device 14, and the slurry 159 containing the electrode catalyst can be transferred from the reactor 152 to the drying device 14 via this pipe or the like. The removal process S43 ends when all the slurry 159 containing the electrode catalyst in the reactor 152 has been removed. It should be noted that the removal process execution unit 158 ​​varies depending on the type of reactor 152, etc., and will not be described in detail here.

[0261] (Drying device)

[0262] The drying apparatus 14 uses a stirring processing device 201 with stirring blades 204 to dry the slurry 159 containing electrode catalyst that was re-slurried in the re-slurrying step S40, thereby preparing multiple solid catalyst filter cakes. The drying apparatus 14 used in this process can be the drying apparatus 14 used in the drying step S3 of the first embodiment, or it can be another drying apparatus 14. Since the structure of the stirring processing device 201 as a drying apparatus is the same as in the first embodiment, its description is omitted.

[0263] The catalyst filter cake preparation step S50, which prepares the solid catalyst filter cake, is the same as the drying step S3 in the first embodiment. It includes an introduction step S31', a drying step S32', a cooling step S33', a slow oxidation step S34' that slowly oxidizes the cooled WET product, and a removal step S35' that removes the slowly oxidized WET product. The operating conditions of each step S31' to S35' are the same as those of each step S31 to S35 in the drying step S3 of the first embodiment. Therefore, the main functions of each step S31' to S35' are also the same as those of each step S31 to S35 in the drying step S3 of the first embodiment.

[0264] In the drying process S32', the weight of the slurry 159 changes by evaporating the steam or gas from the container body 202. The weight of the slurry 159 in the container body 202 is measured by load sensors 212, and the current moisture content of the slurry 159 is calculated from the weight of the slurry 159 at the time of introduction, the weight ratio of electrode catalyst 1 to ion-exchange water determined in the introduction process S41, and the current weight of the slurry 159. The drying process S32' ends when the slurry 159 in the container body 202 reaches a predetermined moisture content below a certain level, thus becoming a solid (granular, cake-like) WET product. In this way, by drying the slurry 159 with uniform moisture content, a catalyst filter cake WET product is prepared, thereby ensuring that the moisture content of the WET product is uniform. Here, the predetermined moisture content is preferably less than 80 wt%, so that the WET product does not adhere to the container body 202 and the stirring blades 204.

[0265] In the slow oxidation step S34', similar to the drying step S3, the cooling medium C in the jacket 206 is discharged from the heating medium inlet 213, the drive device 207 and vacuum pump 234 are stopped, and the supply valve 215 is operated to gradually return the pressure inside the container body 202 to atmospheric pressure, thereby carrying out the slow oxidation of the catalyst filter cake. Therefore, compared with conventional box-type vacuum drying cabinets, the working time can be significantly shortened and automation can be achieved. Furthermore, since the slow oxidation step S34' can also be automated, the slow oxidation step can be implemented more reliably. The slow oxidation process ends when the slow oxidation treatment of the catalyst filter cake inside the container body 202 is completed.

[0266] (Analytical apparatus)

[0267] The analytical apparatus 151 analyzes the physical properties of the WET product obtained after the catalyst filter cake preparation step S50. The analytical apparatus 151 includes a second physical property analysis execution unit 161 that performs a second physical property analysis step S60 on the WET product taken out in the extraction step S35'. In this second physical property analysis step S60, it is preferable to analyze at least the moisture content (wt%) of the WET product. It should be noted that in this embodiment, a method is used to extract a portion of the WET product taken out in the extraction step S35' and perform physical property analysis on it using the analytical apparatus 151, but other analytical methods may also be used.

[0268] [First storage step]

[0269] The first storage step involves storing the WET product of the catalyst filter cake removed in the removal step S35' in a container or bag. The container or bag used in this first storage step is made of plastic and coated with an antistatic agent on its inside. After the second property analysis step, the WET product removed in the removal step S35' is stored in this plastic packaging container or bag. This first storage step is performed in the atmosphere, allowing the WET product to acclimatize to the atmosphere while storing it in the packaging container or bag. In this step, the WET product can be directly stored by placing the plastic packaging container or bag below the opening 208 beforehand in the removal step S35', allowing it to fall from the container body 202 into the packaging container or bag. Alternatively, it can be temporarily removed in the removal step S35' and then stored in the plastic packaging container or bag.

[0270] Next, the WET product containing the catalyst filter cake is further placed in a plastic packaging container or bag. The container used at this time is a stainless steel UN container (a container bearing the "UN Inspection Certificate (UN Mark)" that has passed the container performance test conducted by the Japan Marine Supplies Inspection Association according to international standards: a dangerous goods handling container), with an antistatic agent coated on the inside. This UN container is preferably made of SUS316 stainless steel and is preferably capable of containing substances classified under UN number: 3178, product name: other flammable substances, UN classification: 4.1, with a container class of 2 or 3. After the second storage process, the UN container is transferred and provided to the customer.

[0271] [Second storage step]

[0272] In the second storage step, as an alternative, the aforementioned UN container is used instead of the plastic packaging container or bag used in the first storage step. In this case, the UN container used is configured to seal and store the WET product.

[0273] (Example 2)

[0274] [Processing via reactor (re-pulping step)]

[0275] The powder of electrode catalyst 1 obtained after drying was introduced into a dropping funnel, which is referred to as reactor 152, and a re-slurrying step S40 was performed.

[0276] In the introduction process S41, the capacity of the dropping funnel is selected based on the liquid level in reactor 152 when 100g of electrode catalyst 1 powder and 400ml of ion-exchange water are introduced. For example... Figure 23 As shown, a dropping funnel with an effective capacity of 2L and a stirring blade diameter of 8cm was used. It should be noted that when 100g of electrode catalyst 1 powder and 400ml of ion-exchange water were introduced into the dropping funnel, the liquid surface diameter was 16cm.

[0277] First, in the introduction process S41, 100g of electrode catalyst 1 powder and 400ml of ion-exchange water are introduced into a dropping funnel. Immediately after introduction, approximately one-quarter of the electrode catalyst 1 powder settles at the bottom of the dropping funnel, while the remaining powder accumulates on the surface of the ion-exchange water. After standing for 30 minutes without stirring, most of the electrode catalyst 1 powder settles into the ion-exchange water. However, a portion of the electrode catalyst 1 powder remains accumulated on the surface of the ion-exchange water, forming a layer of about 2-3cm. It should be noted that this accumulated powder has absorbed the ion-exchange water and is in a moist state.

[0278] From this state, the process transitions to mixing step S42, where the stirring device is driven at 60 rpm (60 revolutions per minute) by the stirring blades to mix the electrode catalyst 1 and ion-exchange water at room temperature and atmospheric pressure. Immediately after stirring, the electrode catalyst 1 and ion-exchange water are not immediately mixed. After 30 minutes of stirring, the electrode catalyst 1 and ion-exchange water are mixed only at the center of the dropping funnel along the axis of the rotating stirring blades. The outer periphery of the electrode catalyst 1 and ion-exchange water near the inner wall of the dropping funnel remains the same as before the transition to mixing step S42, with the electrode catalyst 1 powder maintaining a wet, moist powder state. Then, after 60 minutes, the electrode is wetted by the wet powder on the outer periphery of the catalyst 1 and the ion exchange water, that is, the part of the electrode catalyst 1 and the ion exchange water that is stirred and mixed is expanding, and part of the center and outer periphery of the electrode catalyst 1 and the ion exchange water begins to slurry, while most of the outer periphery is still the same as before the transfer of the mixing process S42, and the powder of the electrode catalyst 1 is still in the form of a wet filter cake.

[0279] From this state, 100 ml of ion-exchange water was further introduced, along with 100 g of electrode catalyst 1 powder and 500 ml of ion-exchange water. The stirring device was driven at 60 rpm, and the electrode catalyst 1 and ion-exchange water were mixed at room temperature and atmospheric pressure. After 30 minutes of stirring, the electrode catalyst 1 and ion-exchange water in the dropping funnel became a slurry with a very high viscosity, and the electrode catalyst 1 powder was dispersed in spherical form. Then, after 60 minutes, the amount of electrode catalyst 1 powder dispersed in spherical form decreased, but the powder remained spherical, centered on the edge of the electrode catalyst 1 and ion-exchange water near the inner wall of the dropping funnel, thus not reaching a completely slurry state.

[0280] From this state, the stirring blade speed was further increased. Using 100g of electrode catalyst 1 powder and 500ml of ion-exchange water, the stirring device was driven at 80 rpm, and the electrode catalyst 1 and ion-exchange water were mixed at room temperature and atmospheric pressure. However, compared to when the stirring blade was at 60 rpm, no drastic change occurred. The electrode catalyst 1 powder remained spherically dispersed around the edges of the electrode catalyst 1 and ion-exchange water, and no significant effect was observed from increasing the stirring blade speed. Then, the stirring blade speed was further increased to 250 rpm, with the stirring device driven by 100g of electrode catalyst 1 powder and 500ml of ion-exchange water, and the electrode catalyst 1 and ion-exchange water were mixed at room temperature and atmospheric pressure. As a result, the spherically dispersed electrode catalyst 1 powder largely disappeared at the edges of the electrode catalyst 1 and ion-exchange water, changing into a complete slurry.

[0281] <Evaluation Results>

[0282] When the ratio of the electrode catalyst 1 powder to the ion-exchange water is 1:4 (powder: ion-exchange water = 1:4), even if the electrode catalyst 1 and the ion-exchange water are stirred and mixed, it is difficult to make the whole uniformly wetted and slurry.

[0283] Furthermore, even when the ratio of electrode catalyst 1 powder to ion-exchange water is 1:5 (powder: ion-exchange water = 1:5) and the stirring blade speed is 60 rpm, it is difficult to slurry the electrode catalyst 1 and ion-exchange water. Even when the stirring blade speed is 80 rpm, it is still not possible to completely slurry the electrode catalyst 1 and ion-exchange water. It is clear that since the stirring blade 204 of the stirring treatment device 201 is assumed to have a stirring blade speed of 80 rpm, it is obviously difficult to perform the re-slurrying step S40 using the drying device 14 without using the reactor 152.

[0284] When the ratio of the electrode catalyst 1 powder to the ion-exchange water is 1:5 (powder: ion-exchange water = 1:5) and the stirring blade speed is 250 rpm (more than 80 rpm), the electrode catalyst 1 and the ion-exchange water can be completely slurried.

[0285] (Example 3)

[0286] [Processing via a drying unit (drying step)]

[0287] The filter cake containing the electrode catalyst precursor, obtained after being processed by a filter press (which serves as a cleaning device), is introduced into a stirring processing unit 201 (which serves as a drying device) for a drying step S3.

[0288] In the introduction process S31, 4.98 kg of a substance with a moisture content of 72.1 wt% and an apparent density of 540 kg / m³ was introduced. 3 (The apparent density after compaction is 700 kg / m³) 3 The filter cake. Hereinafter, the moisture content (water content) of the filter cake or slurry is the value obtained by dividing the weight of the water contained in the filter cake by the weight of the catalyst powder contained in the filter cake plus the weight of the water. The weight of the water is detected by heating the measuring container at 70°C in air for 70 minutes using an infrared moisture meter and measuring the weight change of the water-containing filter cake in the measuring container before and after the measurement.

[0289] In the drying process S32, the vacuum pump 234 is driven to reduce the pressure inside the container body 202 to 12.3 kPa using gauge pressure. The stirring blades 204 rotate at a speed of 85 revolutions per minute. Steam S is injected into the jacket 206 through the heating medium inlet 213, causing the heating temperature t1 of the container body 202 to reach 110°C. The changes in the tank temperature t2 of the container body 202, the temperature of the electrode catalyst precursor (measured sample temperature) t3, and the moisture content C1 of the filter cake over 180 minutes are measured. The results are presented in graphs and tables. Figure 24 (Run1 drying curve)

[0290] In the 180-minute drying process S32, the temperature inside the container body 202 rises from 18.8°C to 77.8°C, and the temperature of the catalyst precursor for the electrode also rises from 19.7°C to 108.9°C. Then, a cooling process S33 and a slow oxidation process S34 are performed sequentially. In the extraction process S35, 1.4 kg of a product with a moisture content of 2.2 wt% and an apparent density of 450 kg / m³ is extracted. 3 (The apparent density after compaction is 480 kg / m³) 3 ) filter cake.

[0291] In addition, the amount of electrode catalyst attached inside the container body 202 is 6.8g, and the amount of electrode catalyst precursor taken out as a sample for determination is 46g. Moreover, the amount of condensate discharged through the bag filter 231 and condensed and recovered by the condenser 233 is 3.1kg.

[0292] (Example 4)

[0293] The slurry obtained after being processed by the reactor 152, in which the electrode has been re-slurried with the catalyst, was introduced into the stirring treatment device 201, which is a drying device, and a drying step S3 was performed.

[0294] In the introduction step S31, 11.25 kg of slurry with a moisture content of 93.3 wt% was introduced. Here, the moisture content of the slurry was calculated by setting the moisture content of the electrode catalyst powder to 5 wt% and combining it with the weight of the ion-exchange water introduced in the re-slurrying step S40.

[0295] In the drying process S32, the vacuum pump 234 is driven to reduce the pressure inside the container body 202 to 12.3 kPa using gauge pressure. This causes the stirring blades 204 to rotate at a speed of 85 revolutions per minute. Steam S is injected into the jacket 206 through the heating medium inlet 213, raising the heating temperature t4 of the container body 202 to 110°C. The changes in the tank temperature t5, the temperature of the catalyst precursor for the electrode (measured sample temperature) t6, and the moisture content C2 of the filter cake over 170 minutes are measured. The results are presented in graphs and tables. Figure 25 (Run2 drying curve).

[0296] In the 170-minute drying process S32, the temperature t5 inside the container body 202 rises from approximately 20°C to approximately 50°C, and the temperature t6 of the electrode catalyst precursor also rises from 20.2°C to 52.5°C. Then, a cooling process S33 and a slow oxidation process S34 are performed sequentially. In the extraction process S35, 1.1 kg of a product with a moisture content of 41.1 wt% and an apparent density of 840 kg / m³ is extracted. 3 (The apparent density after compaction is 900 kg / m³)3 ) filter cake.

[0297] In addition, the amount of electrode catalyst attached inside the container body 202 is 317g, and the amount of electrode catalyst precursor taken out as a sample for determination is 45g. Then, it is discharged through bag filter 231, and the amount of condensate recovered by condenser 233 is 9.3kg.

[0298] <Evaluation Results>

[0299] [Preparation of catalysts for electrodes]

[0300] (1) The process involves manufacturing the electrode catalyst precursor in a reactor in step S1, and filtering, washing and dehydrating it in a filter press in step S2 to obtain an electrode catalyst precursor with a water content of 60-80 wt%. The electrode catalyst precursor is then dried and coarsely pulverized in a stirring treatment device 201 in step S3 to obtain an electrode catalyst with a water content of 1-5 wt%. The electrode catalyst is then pulverized in a pulverizer to obtain the electrode catalyst powder.

[0301] In this process, if the wetted catalyst filter cake, which is a precursor for electrode catalyst and has a water content of 72.1 wt%, obtained by filtering, washing, and dehydrating in the cleaning step S2 using a filter press, is introduced into the stirring treatment device 201, then as follows... Figure 24 As shown, in the drying step S32 of drying step S3, the moisture content of the wetted catalyst filter cake is made to reach 5.0 wt% in 145 minutes, that is, the electrode catalyst with 5.0 wt% as the target in step (1) can be made in 145 minutes.

[0302] (2) The process involves manufacturing the electrode catalyst precursor in a reactor in step S1, and filtering, washing and dehydrating it in a centrifuge in step S2 to obtain an electrode catalyst precursor with a water content of 60-80 wt%. The electrode catalyst precursor is then dried and coarsely pulverized in step S3 by a stirring treatment device 201 to obtain an electrode catalyst with a water content of 1-5 wt%. The electrode catalyst is then pulverized by a pulverizer to obtain the powder of the electrode catalyst.

[0303] In this process as a comparative example, if the wetted catalyst filter cake, which is a precursor for the electrode catalyst and has a water content of 72.1 wt% obtained by filtering, washing and dehydrating in the washing step S2 by centrifugation, is introduced into the stirring treatment device 201, then in the drying step S32 of the drying step S3, the water content of the wetted catalyst filter cake is made to reach 5.0 wt% in 240 minutes, that is, the electrode catalyst with a water content of 5.0 wt% as targeted in process (2) can be produced in 240 minutes.

[0304] [Preparation of catalyst filter cake by wetting catalyst powder for electrode use]

[0305] (3) In the re-slurrying step S40, the powder of the electrode catalyst obtained in (1) is re-slurryed in a vessel, which is a reactor 152, and the slurry containing the electrode catalyst is dehydrated by a centrifuge to obtain an electrode catalyst with a water content of 60-80 wt%.

[0306] In this process, a slurry with a water content of 93.3 wt% used in Example 4 is prepared by a reactor, and the slurry is dehydrated by a centrifuge, thereby producing a wetted catalyst filter cake with a water content of 72.1 wt%.

[0307] (4) In the catalyst filter cake preparation step S50, the electrode catalyst with a water content of 60-80 wt% obtained in step (3) is dried and coarsely crushed by the stirring treatment device 201 to obtain an electrode catalyst with a water content of 20-75 wt%, preferably an electrode catalyst with a water content of 30-70 wt%.

[0308] In this process, if a wetted catalyst filter cake with a moisture content of 72.1 wt% is introduced into the stirring treatment device 201, then as follows... Figure 24 As shown, in drying step S32 of drying step S3, the moisture content of the wetted catalyst filter cake is reduced to 20.3-69.8 wt% in 5-120 minutes, thereby further reducing the moisture content. Thus, in step (4), an electrode catalyst with a target moisture content of 20-75 wt% can be produced within 5-120 minutes. Furthermore, the moisture content of the wetted catalyst filter cake is reduced to 31.3-69.8 wt% in 5-95 minutes, meaning that an electrode catalyst with a preferred moisture content of 30-70 wt% can be produced within 5-95 minutes in step (4).

[0309] (5) In the re-slurrying step S40, the powder of the electrode catalyst obtained in step (1) is re-slurryed in a vessel serving as reactor 152, and the slurry containing the electrode catalyst is dehydrated by a filter press to obtain an electrode catalyst with a water content of 60-80 wt%. In the drying step S3, the electrode catalyst is dried and coarsely pulverized by a stirring treatment device 201 to obtain an electrode catalyst with a water content of 20-75 wt%, preferably an electrode catalyst with a water content of 30-70 wt%.

[0310] By comparing steps (1) and (2), it can be seen that a filter press can be used instead of a centrifuge for dehydration, and in this case, it can be understood that the dehydration time can be shortened according to the first embodiment described above. Therefore, it can be determined that by dehydrating with a filter press to produce a wetted catalyst filter cake with a moisture content of 72.1 wt%, and then drying and coarsely pulverizing it by the stirring treatment device 201, the same result as step (4) can be obtained.

[0311] (6) In the re-slurrying step S40, the powder of the electrode catalyst obtained in step (1) is re-slurryed in a vessel serving as reactor 152, and the slurry containing the electrode catalyst is directly introduced into a stirring treatment device 201, and the slurry is dried by the stirring treatment device 201 and then coarsely crushed to obtain an electrode catalyst with a water content of 20 to 75 wt%, preferably an electrode catalyst with a water content of 30 to 70 wt%.

[0312] In this process, if a slurry with a water content of 93.3 wt% that has undergone re-slurrying in a reactor is introduced into the mixing and processing device 201, then as follows... Figure 25 As shown, in the drying step S32' of catalyst filter cake preparation step S50, the moisture content of the wetted catalyst filter cake is reduced to 41.1-74.7 wt% in 87-170 minutes, thereby further reducing the moisture content. Although it takes a little more time than step (4), an electrode catalyst with a moisture content of 30-70 wt% as targeted in step (6) can be produced in 87-170 minutes.

[0313] (Example for reference)

[0314] (7) Step (1) involves introducing the powder of the electrode catalyst obtained in step (1) and ion-exchange water into a stirring treatment device 201, and re-slurrying in the stirring treatment device 201. The slurry containing the electrode catalyst in the stirring treatment device 201 is dried by the stirring treatment device 201 and then coarsely crushed to obtain an electrode catalyst with a water content of 20 to 75 wt%, preferably an electrode catalyst with a water content of 30 to 70 wt%.

[0315] In this process, as described above, the stirring treatment device 201 cannot re-slurry the electrode catalyst powder and ion-exchange water.

[0316] The present invention has been described above based on the embodiments and examples, but the present invention can be implemented in various modifications. In particular, there are no particular limitations on the electrode catalyst precursor manufacturing apparatus 12 (reaction process, electrode catalyst precursor manufacturing apparatus step S1) and the cleaning apparatus 13 (cleaning step S2), and various modifications can be adopted.

[0317] For example, the structure of the cleaning device 13 is not limited to... Figure 2 The structure shown, and the structure of filter chamber 112 are not limited to those shown. Figures 3 to 10 The structure shown can be modified in various ways, as long as it achieves the same effect in each of the steps S21 to S27 of the cleaning step S2 and the pressing step in this embodiment. Furthermore, even in the drying apparatus 14, its structure is not limited to... Figure 11 The structure shown, and the structure of the container body 202 are not limited to Figures 11-1 The structure shown in 3 can be modified in various ways, as long as the same effect can be obtained in each step S31 to S35 of the drying step S3 in this embodiment.

[0318] Industrial availability

[0319] According to the manufacturing system and method for electrode catalysts of the present invention, by eliminating the operation of transferring the electrode catalyst precursor by the operator and shortening the drying time of the electrode catalyst precursor, the labor and time required for manufacturing electrode catalysts with reduced halogen content, especially reduced chlorine content, can be significantly reduced.

[0320] Therefore, this invention is not only applicable to the manufacturing system and method for electrode catalysts in the electrical equipment industry such as fuel cells, fuel cell vehicles, and mobile phones, but also applicable to the manufacturing system and method for electrode catalysts in household fuel cells (ENE-FARM), cogeneration systems, etc., which contributes to the development of energy industry and environmental technology related aspects.

Claims

1. A manufacturing system of a catalyst for electrode, for manufacturing a catalyst for electrode, the manufacturing system comprising: a catalyst for electrode precursor manufacturing device for manufacturing a catalyst for electrode precursor which is a raw material of a catalyst for electrode; and a drying device which dries the catalyst for electrode precursor washed by the washing device by a stirring treatment device provided with a stirring blade having a spiral belt-shaped rotating wing, the drying device comprising each unit which carries out the following processes: a cleaning device which cleans the electrode catalyst precursor; an introducing process which introduces the catalyst for electrode precursor into a container main body of the stirring treatment device; a drying process which dries the catalyst for electrode precursor by stirring and mixing the catalyst for electrode precursor in the container main body by the stirring blade while heating the container main body and performing a reduced pressure; a cooling process which cools the catalyst for electrode precursor by stirring and mixing the catalyst for electrode precursor in the container main body by the stirring blade while cooling the container main body and performing a reduced pressure; a slow oxidation process which supplies a mixed gas in which nitrogen and oxygen are mixed at an arbitrary ratio and the oxygen concentration is adjusted, or a mixed gas in which nitrogen and air are mixed at an arbitrary ratio and the oxygen concentration is adjusted, to the container main body from a gas ejection hole provided in the container main body, thereby recovering the container main body to an atmospheric pressure, and thereby performing a slow oxidation treatment on the catalyst for electrode precursor; and a taking-out process which takes out the catalyst for electrode precursor in the container main body by ejecting gas downward from the gas ejection hole. the stirring blade has: a rotating main shaft which rotates the stirring blade by rotation by a driving device; the spiral belt-shaped rotating wing which stirs and mixes the catalyst for electrode precursor in the container main body; and a rotating wing support which is connected to the rotating main shaft and the spiral belt-shaped rotating wing, wherein 2. The manufacturing system of the catalyst for an electrode according to claim 1, wherein the rotating main shaft and the rotating wing support are formed as a hollow pipe, the rotating wing support is provided with a gas ejection hole at the lower side of the front end portion, the rotating main shaft is connected to a gas flow path.

3. A manufacturing method of a catalyst for electrode, for manufacturing a catalyst for electrode, the manufacturing method comprising: a catalyst for electrode precursor manufacturing step for manufacturing a catalyst for electrode precursor which is a raw material of a catalyst for electrode; and a drying step which dries the washed catalyst for electrode precursor washed in the washing step by a stirring treatment device provided with a stirring blade having a spiral belt-shaped rotating wing, the drying step comprising: a drying process which dries the catalyst for electrode precursor by stirring and mixing the catalyst for electrode precursor in a container main body by the stirring blade while heating the container main body and performing a reduced pressure; a cooling process which cools the catalyst for electrode precursor by stirring and mixing the catalyst for electrode precursor in the container main body by the stirring blade while cooling the container main body and performing a reduced pressure; and ​ a cleaning step which cleans the electrode with a catalyst precursor; ​ ​ ​ ​ ​ ​ a slow oxidation step of supplying a mixed gas of nitrogen and oxygen mixed at an arbitrary ratio and having an oxygen concentration adjusted, or a mixed gas of nitrogen and air mixed at an arbitrary ratio and having an oxygen concentration adjusted, from a gas ejection hole provided in the container main body into the container main body to return the inside of the container main body to an atmospheric pressure, thereby performing a slow oxidation treatment on the electrode catalyst precursor.

4. The electrode catalyst production method according to claim 3, further comprising a taking-out step of taking out the electrode catalyst precursor in the container main body by ejecting gas downward from the gas ejection hole, wherein the taking-out step comprises a scraping-off step of ejecting gas downward from the gas ejection hole provided at the front end of the rotary wing support that supports the spiral belt-shaped rotary wing.

5. The electrode catalyst production method according to claim 3, further comprising: a first analysis step of performing physical property analysis on the electrode catalyst precursor obtained in the drying step; a reslurry step of mixing the electrode catalyst precursor obtained in the drying step with ion exchange water to prepare a slurry again; and a catalyst filter cake production step of drying the slurry obtained in the reslurry step to produce a plurality of solid catalyst filter cakes having a water content adjusted to a prescribed range.

6. The electrode catalyst production method according to claim 5, wherein the stirring type drying device used in the catalyst filter cake production step is the stirring treatment device.

7. The electrode catalyst production method according to claim 5 or 6, wherein a reactor provided with a stirring device is used in the reslurry step.

8. The electrode catalyst production method according to claim 7, wherein the reactor is the stirring treatment device.

9. The electrode catalyst production method according to claim 5, wherein the water content of the catalyst filter cake is less than 80 wt%.

10. The electrode catalyst production method according to claim 5, further comprising a second analysis step of measuring the water content of the catalyst filter cake obtained in the catalyst filter cake production step.

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