Electrode catalyst manufacturing system and manufacturing method

Abstract

Provided are a production system and a production method which are for a catalyst for an electrode and by which the work of an operator for transferring a catalyst precursor for an electrode can be eliminated and the drying time of the catalyst precursor for an electrode can be shortened. A production system 10 for a catalyst for an electrode includes a production device 12 for a catalyst precursor for an electrode, a washing device 13, and a drying device 14, and has a configuration wherein the drying device 14 is provided with means for executing: an introduction step S31 for introducing the catalyst precursor for an electrode into a container body 202; a drying step S32 for drying the catalyst precursor for an electrode by heating and depressurizing the container body 202, and stirring and mixing the catalyst precursor for an electrode with a stirring blade 204; a cooling step S33 for cooling the catalyst precursor for an electrode by cooling and depressurizing the container body 202, and stirring and mixing the catalyst precursor for an electrode with the stirring blade 204; a slow oxidation step S34 for supplying air into the container body 202 and slowly oxidizing the catalyst precursor for an electrode; and an extraction step S35 for extracting the catalyst precursor for an electrode in the container body 202.

Description

[Technical field]

[0001] The present invention relates to a system and method for producing an electrode catalyst. [Background technology]

[0002] So-called solid polymer electrolyte fuel cells (hereinafter referred to as "PEFC" as necessary) have an operating temperature of about room temperature to 80°C. In addition, PEFCs can be made lightweight because inexpensive general-purpose plastics can be used for the components that make up the fuel cell body. Furthermore, PEFCs allow the solid polymer electrolyte membrane to be made thin, which reduces electrical resistance and makes it relatively easy to reduce power generation losses. As such, PEFCs have many advantages, making them suitable for use in fuel cell vehicles, home cogeneration systems, and the like.

[0003] As an electrode catalyst for PEFC, for example, an electrode catalyst in which platinum (Pt) or a platinum (Pt) alloy, which is an electrode catalyst component, is supported on a carbon carrier, is known. When such an electrode catalyst is used as an electrode catalyst for a fuel cell, if the electrode catalyst contains a large amount of impurities derived from the raw materials or impurities mixed in from the manufacturing equipment, sufficient catalytic activity cannot be obtained, corrosion of the catalyst layer occurs, and the life of the fuel cell is shortened. For this reason, it is preferable to keep the impurity content of the electrode catalyst, particularly the chlorine content, low. Here, examples of impurities include chemical species belonging to halogens (ions and their salts, etc.), organic substances (organic acids, their salts, condensates of organic acids), and the like.

[0004] For this reason, a process for removing chlorine may be carried out after the production of the electrode catalyst precursor, which is the raw material of the electrode catalyst, and in this case, a process for drying the electrode catalyst precursor after the washing process is carried out. For example, Patent Documents 1 and 2 describe that a shelf dryer, rotary dryer, flash dryer, spray dryer, stirring dryer, freeze dryer, etc. can be used as a drying method after washing. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-158674 A [Patent Document 2] JP 2014-42910 A Summary of the Invention [Problem to be solved by the invention]

[0006] For example, when drying the electrode catalyst precursor using a shelf dryer, in order to perform drying efficiently, the wet electrode catalyst precursor lumps are crushed into small pieces and then placed in the shelf dryer for drying, and even after drying, a process of crushing the dried electrode catalyst precursor lumps into small pieces is sometimes performed. This conventional method of drying the electrode catalyst precursor requires a dedicated crusher for crushing the wet electrode catalyst precursor after washing and a hammer mill for crushing the dried electrode catalyst precursor, and the electrode catalyst precursor needs to be moved from the crusher to the dryer and from the dryer to the hammer mill. However, platinum constituting the electrode catalyst precursor has high activity and may burn if it suddenly comes into contact with oxygen in the air, so careful work is required. In addition, the method of drying the electrode catalyst precursor using a shelf dryer has the problem that the drying speed is slow and takes a long time because the electrode catalyst precursor is left stationary and dried by radiation heat transfer. Patent documents 1 and 2 describe that an agitator dryer can be used to dry the fuel cell catalyst, but do not describe the specific configuration or operating conditions of the agitator dryer.

[0007] The present invention has been made in consideration of the above circumstances, and provides a system and method for manufacturing an electrode catalyst that can significantly reduce the effort and time required to manufacture an electrode catalyst by eliminating the need for workers to transfer an electrode catalyst precursor and shortening the drying time of the electrode catalyst precursor. [Means for solving the problem]

[0008] In order to solve such problems, the present invention provides: an electrode catalyst precursor manufacturing apparatus for manufacturing an electrode catalyst precursor, which is a raw material for an electrode catalyst; A cleaning device for cleaning the electrode catalyst precursor; a drying device that dries the electrode catalyst precursor washed by the washing device using an agitation treatment device equipped with an agitation blade having a spiral ribbon rotor, The drying device is an introduction step of introducing the electrode catalyst precursor into a vessel body of the stirring treatment device; a drying step of heating the container body while reducing the pressure, and stirring and mixing the electrode catalyst precursor in the container body with the stirring blade, thereby drying the electrode catalyst precursor; a cooling step of cooling the electrode catalyst precursor by cooling and reducing the pressure of the container body and stirring and mixing the electrode catalyst precursor in the container body with the stirring blade; a gradual oxidation step of supplying air into the container body and subjecting the electrode catalyst precursor to a gradual oxidation treatment; and a removal step of removing the electrode catalyst precursor from the container body.

[0009] The electrode catalyst manufacturing system includes: the stirring blade includes a main shaft that is rotated by a drive device to rotate the stirring blade, the spiral ribbon rotor that stirs and mixes the electrode catalyst precursor in the container body, and a rotor support that connects the main shaft and the spiral ribbon rotor, The rotor shaft and the rotor support are formed in a hollow tubular shape, The rotor support has a gas outlet hole on the lower side of the tip, The rotating shaft may be connected to a gas flow path.

[0010] The present invention also provides a method for producing a semiconductor device comprising the steps of: an electrode catalyst precursor producing step of producing an electrode catalyst precursor which is a raw material for the electrode catalyst; a washing step of washing the electrode catalyst precursor; a drying step of drying the electrode catalyst precursor after the washing step by using an agitation treatment device equipped with an agitation blade having a spiral ribbon rotor, The drying step comprises: The above Mixing treatment equipment a drying step of heating the container body while reducing the pressure, and stirring and mixing the electrode catalyst precursor in the container body with the stirring blade, thereby drying the electrode catalyst precursor; a cooling step of cooling the electrode catalyst precursor by cooling and reducing the pressure of the container body and stirring and mixing the electrode catalyst precursor in the container body with the stirring blade; and a gradual oxidation step of supplying air into the container body and subjecting the electrode catalyst precursor to a gradual oxidation treatment.

[0011] In the method for producing an electrode catalyst, The method further includes a removal step of removing the electrode catalyst precursor from the container body, The removing step may include a scraper step of ejecting gas downward from gas ejection holes provided at the tip of a rotor support that supports the spiral ribbon rotor.

[0012] In the method for producing an electrode catalyst, a first analysis step of performing a physical property analysis of the electrode catalyst precursor obtained through the drying step; a reslurry step of mixing the electrode catalyst precursor obtained through the drying step with ion-exchanged water to prepare a slurry again; A catalyst cake preparation step of drying the slurry obtained through the reslurry step to prepare a plurality of solid catalyst cakes having a moisture content adjusted to a predetermined range; It may further include.

[0013] In the method for producing an electrode catalyst, the stirring type drying device used in the catalyst cake preparation step may be the stirring treatment device.

[0014] In the method for producing an electrode catalyst, a reactor equipped with a stirring device may be used in the reslurry step.

[0015] In the method for producing an electrode catalyst, the reactor may be the stirring treatment device.

[0016] In the method for producing an electrode catalyst, the water content of the catalyst cake may be less than 80 wt %.

[0017] The method for producing an electrode catalyst may further include a second analysis step of measuring the water content of the catalyst cake obtained via the catalyst cake preparation step. Effect of the Invention

[0018] According to the electrode catalyst manufacturing system and manufacturing method of the present invention, the labor and time required to manufacture an electrode catalyst having a low halogen content, particularly a low chlorine content, can be significantly reduced by eliminating the need for an operator to transfer the electrode catalyst precursor and shortening the drying time of the electrode catalyst precursor. [Brief description of the drawings]

[0019] [Figure 1] 1 is a block diagram showing a preferred embodiment of a system for producing an electrode catalyst according to the present invention. [Diagram 2] 1 is a side view showing a preferred embodiment of a cleaning device in a production system and a production method for an electrode catalyst of the present invention. [Diagram 3] 1 is a perspective view showing a preferred embodiment of an operating state of a dehydration device in a plate closing step of a production system and a production method for an electrode catalyst according to the present invention. FIG. [Figure 4]1 is a perspective view showing a preferred embodiment of an operating state of a dehydration device in a pressing step of a production system and production method for an electrode catalyst of the present invention. FIG. [Diagram 5] 1 is a perspective view showing a preferred embodiment of an operating state of a dehydration device in a normal washing step of a production system and a production method for an electrode catalyst of the present invention. FIG. [Figure 6] 1 is a perspective view showing a preferred embodiment of an operating state of a dehydration device in a backwashing step of a production system and a production method for an electrode catalyst of the present invention. FIG. [Figure 7] 1 is a perspective view showing a preferred embodiment of an operating state of a dehydration device in a plate opening step of a production system and a production method for an electrode catalyst according to the present invention. FIG. [Figure 8] FIG. 1 is a perspective view showing a preferred embodiment of an operating state of a dewatering device in a cake peeling step of a production system and production method for an electrode catalyst of the present invention. [Figure 9] 1 is a perspective view showing a preferred embodiment of an operating state of a dehydrator in a filter cloth washing step of a production system and production method for an electrode catalyst of the present invention. FIG. [Figure 10] 1 is a perspective view showing a preferred embodiment of an operating state of a dehydration device in a squeezing step of a production system and a production method for an electrode catalyst of the present invention. FIG. [Figure 11] 1 is a schematic diagram showing a preferred embodiment of a drying device in a production system and a production method for an electrode catalyst of the present invention. [Figure 12] FIG. 1 is a perspective view showing a preferred embodiment of an agitating blade of a drying device in a production system and production method for an electrode catalyst of the present invention. [Figure 13] FIG. 1 is a schematic diagram showing a preferred embodiment of an operating state of a drying device in a drying step of a production system and a production method for an electrode catalyst of the present invention. [Figure 14] 1 is a schematic cross-sectional view showing an example of the structure of an electrode catalyst (core-shell catalyst) that can be produced by the electrode catalyst production system and production method of the present invention. FIG. [Figure 15] FIG. 2 is a schematic cross-sectional view showing another example of the structure of an electrode catalyst (core-shell catalyst) that can be produced by the electrode catalyst production system and production method of the present invention. [Figure 16] FIG. 2 is a schematic cross-sectional view showing another example of the structure of an electrode catalyst (core-shell catalyst) that can be produced by the electrode catalyst production system and production method of the present invention. [Figure 17] FIG. 2 is a schematic cross-sectional view showing another example of the structure of an electrode catalyst (core-shell catalyst) that can be produced by the electrode catalyst production system and production method of the present invention. [Figure 18] FIG. 1 is a flow chart showing a preferred embodiment of the flow of a method for producing an electrode catalyst of the present invention. [Figure 19] FIG. 2 is a flow chart showing a preferred embodiment of the flow of a washing step in the method for producing an electrode catalyst of the present invention. [Figure 20] FIG. 2 is a flow chart showing a preferred embodiment of the flow of a drying step in the method for producing an electrode catalyst of the present invention. [Figure 21] FIG. 2 is a block diagram showing a further preferred embodiment of the electrode catalyst manufacturing system of the present invention. [Figure 22] FIG. 2 is a flow chart showing a preferred embodiment of the flow of the reslurry step in the method for producing an electrode catalyst of the present invention. [Diagram 23] FIG. 2 is a schematic diagram of a dropping funnel used in a mixing test in the reslurry step of the manufacturing method for an electrode catalyst of the present invention. [Figure 24] 4 is a graph showing changes over time in the heating temperature of the container body, the temperature inside the container body, the temperature of the electrode catalyst precursor, and the moisture content of the cake in the drying step of the present invention. [Diagram 25] 4 is a graph showing changes over time in the heating temperature of the container body, the temperature inside the container body, the temperature of the electrode catalyst precursor, and the moisture content of the cake in the drying step of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, preferred embodiments of the electrode catalyst manufacturing system and manufacturing method of the present invention will be described with reference to the drawings. EXAMPLES

[0021] <Electrode catalyst manufacturing system> Fig. 1 is a block diagram showing an outline of an electrode catalyst manufacturing system according to the first embodiment. The electrode catalyst manufacturing system 10 includes an electrode catalyst precursor manufacturing apparatus 12 that manufactures an electrode catalyst precursor, which is a raw material for an electrode catalyst 1 (see Fig. 18), a washing apparatus 13 that washes the electrode catalyst precursor by a filter press, and a drying apparatus 14 that dries an electrode catalyst precursor 41 (see Fig. 19) after washing by the washing apparatus 13 by an agitation processing apparatus equipped with an agitation blade having a spiral ribbon rotor.

[0022] (Electrode catalyst precursor production equipment) The electrode catalyst precursor manufacturing apparatus 12 manufactures an electrode catalyst precursor, which is a raw material for the electrode catalyst 1. The electrode catalyst precursor manufacturing apparatus 12 includes a reaction process execution means 21 that executes a reaction process for manufacturing an electrode catalyst precursor. In the reaction process, an electrode catalyst precursor, which is a raw material for the electrode catalyst 1, is manufactured by supporting the catalyst components (core part 4, shell part 5) of the electrode catalyst 1 on the support 2 (see FIG. 14). The manufacturing method of the electrode catalyst precursor is not particularly limited as long as it is a method that can support the catalyst components of the electrode catalyst 1 on the support 2. For example, there can be mentioned an impregnation method in which a solution containing the catalyst components of the electrode catalyst 1 is contacted with the support 2 to impregnate the support 2 with the catalyst components, a liquid phase reduction method in which a reducing agent is added to a solution containing the catalyst components of the electrode catalyst 1, an electrochemical deposition method such as an underpotential deposition (UPD) method, a chemical reduction method, a reduction deposition method using adsorbed hydrogen, a surface leaching method of an alloy catalyst, a displacement plating method, a sputtering method, a vacuum deposition method, or the like.

[0023] (Cleaning Equipment) The washing device 13 uses a filter press to wash the electrode catalyst precursor produced in the electrode precursor production device 12. In the washing device 13, filtration and dehydration are also performed in addition to washing the electrode catalyst precursor.

[0024] FIG. 2 shows an example of a cleaning device 13 that performs a filter press. In the cleaning device 13 shown in the figure, a plurality of dehydration devices 104 are arranged in parallel in the horizontal direction on a guide rail 103 that is bridged between a front frame 101 and a rear frame 102. These dehydration devices 104 are supported so that they can move horizontally on the guide rail 103. For example, an electric cylinder 105 is supported on the rear frame 102, and the dehydration devices 104 are tightened by a pressing member 106 that reciprocates by the driving force of the electric cylinder 105. Such a cleaning device 13 for a filter press has been publicly known, and for example, one described in Japanese Patent No. 5950207 is known. In particular, the dehydration device 104 is known, for example, one described in Japanese Patent No. 5327000.

[0025] The outline of the cleaning flow using a filter press will be explained (see Figs. 3 to 10). First, the raw liquid 30 is supplied to the filter chamber 112 between the closed filter plates 111, 111', whereupon the raw liquid 30 passes through the filter cloth 113 and is filtered, and the filtrate 42 is discharged to the outside. The solid matter captured by the filter cloth 113 is dehydrated while forming a cake layer. After the dehydration is completed, the electric cylinder 105 is contracted to simultaneously open the multiple filter plates 111, 111', and at the same time, the filter cloth 113 is moved downward to discharge the dehydrated cake 40.

[0026] As shown in the block diagram of Fig. 1, the cleaning device 13 includes a plate closing step execution means 31, a pressing step execution means 32, a forward cleaning step execution means 33, a reverse cleaning step execution means 34, a plate opening step execution means 35, a cake peeling step execution means 36, and a filter cloth cleaning step execution means 37, which are means for respectively executing a plate closing step, a pressing step, a forward cleaning step, a reverse cleaning step execution means 34, a plate opening step execution means 35, a cake peeling step execution means 36, and a filter cloth cleaning step execution means 37. The configuration of each step S21 to S27 shown in the flow diagram of the manufacturing method of the electrode catalyst 1 in Fig. 19 described later will be described below.

[0027] [Closing process] The plate closing step S21 is a step of clamping the filter plates 111, 111' to form the filter chamber 112, and is executed by the plate closing step executing means 31. Fig. 3 is a diagram of one dewatering device 104 in the cleaning device 13 of Fig. 2, showing a preferred embodiment of the operating state in the plate closing step S21. The plate closing step executing means 31 drives the electric cylinder 105 to move the pressing member 106 toward the front frame 101, thereby bringing the two filter plates 111, 111' of the dewatering device 104 closer to each other and clamping them together to form the filter chamber 112.

[0028] [Press-fitting process] The press-in step S22 is a step of pressurizing the liquid (raw liquid) 30 containing the electrode catalyst precursor from the raw liquid supply pipe 114 into the filter chamber 112 to filter it, and discharging the filtrate 42 from the filtrate discharge ports 115, 115', and is executed by the press-in step execution means 32. FIG. 4 is a diagram of one dehydrator 104 extracted from the cleaning device 13 of FIG. 2, and shows a preferred embodiment of the operating state in the press-in step S22. When the press-in step execution means 32 pressurizes the liquid 30 containing the electrode catalyst precursor from the raw liquid supply pipe 114 into the filter chamber 112, the moisture in the liquid 30 containing the electrode catalyst precursor seeps into the filter bed 116 through the filter cloth 113 and is discharged to the outside from the filtrate discharge ports 115, 115'. As a result, the liquid 30 containing the electrode catalyst precursor pressed into the filter chamber 112 is filtered. That is, the solid components in the electrode catalyst precursor-containing liquid 30 remain in the filtration chamber 112 as a cake 40 containing the electrode catalyst precursor, and the water in the electrode catalyst precursor-containing liquid 30 is discharged to the outside as a filtrate 42.

[0029] In addition, in this pressing step S22, the cake 40 containing the electrode catalyst precursor is formed to have a thickness within a range determined experimentally in advance. The thickness of the cake 40 is determined experimentally in advance, taking into consideration the cleaning degree and cleaning time required for the electrode catalyst precursor to be used.

[0030] Here, when the electrode catalyst used uses conductive carbon as a carrier, the thickness T of the cake 40 during the pressing step S22 is preferably adjusted to 5 to 10 mm. When the thickness T of the cake 40 is 10 mm or less, a sufficient cleaning effect can be obtained relatively easily by adjusting the cleaning time in the forward cleaning step and / or reverse cleaning step described below. When the thickness T of the cake 40 exceeds 10 mm, there is a strong tendency that a sufficient cleaning effect cannot be obtained even if the cleaning time in the forward cleaning step and / or reverse cleaning step described below is extended.

[0031] Furthermore, when the thickness T of the cake 40 is 5 mm or more, cracks are less likely to form in the cake, and there is a greater tendency to prevent the formation of a path through which the wash water flows from the upstream surface of the cake to the downstream surface of the cake without passing through the cake.

[0032] [Main cleaning process] The forward washing step S23 is a step of supplying the washing water 43 from the raw liquid supply pipe 114 to the filtration chamber 112, passing the washing water 43 through the cake 40 containing the electrode catalyst precursor, and discharging the washing water 43 from the filtrate discharge ports 115, 115', and is executed by the forward washing step execution means 33. FIG. 5 is a diagram of one dehydrator 104 extracted from the washing device 13 of FIG. 2, and shows a preferred embodiment of the operating state in the forward washing step S23. The forward washing step execution means 33 causes the washing water 43 to flow from the raw liquid supply pipe 114 toward the filtrate discharge ports 115, 115', and washes the cake 40 containing the electrode catalyst precursor remaining in the filtration chamber 112 in the pressure-in step S22. This can reduce the electrical conductivity ρ of the filtrate measured by the JIS standard test method (JIS K0522), and can reduce the halogen content, especially the chlorine content, of the electrode catalyst precursor.

[0033] In the forward washing step S23, it is preferable to switch the temperature of the washing water 43 when the electrical conductivity ρ of the filtrate becomes equal to or lower than a predetermined value during washing. For example, the washing water 43 can be switched from room temperature water (e.g., 23°C) to heated water (e.g., 70°C) when the electrical conductivity ρ of the filtrate becomes equal to or lower than a predetermined value. The predetermined value of the electrical conductivity ρ of the filtrate is preferably a value 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.

[0034] [Backwashing process] The backwashing step S24 is a step of supplying the washing water 43 from the filtrate discharge port 115 to the filtration chamber 112, passing the washing water 43 through the cake 40 containing the electrode catalyst precursor, and then discharging the washing water 43 from a different filtrate discharge port 115', which is different from the filtrate discharge port 115 for supplying the washing water 43, and is executed by the backwashing step execution means 34. FIG. 6 is a diagram of one dehydrator 104 in the washing device 13 of FIG. 2, and shows a preferred embodiment of the operating state in the backwashing step S24. The dehydrator 104 has, for example, at least two filtrate discharge ports 115, 115'. In contrast to the forward washing step S23, the backwashing step execution means 34 causes the washing water 43 to flow from the filtrate discharge port 115 toward the filtration chamber 112, thereby washing the cake 40 containing the electrode catalyst precursor remaining in the filtration chamber 112. The filtrate 42 is discharged, for example, from a different filtrate discharge port 115', which is different from the filtrate discharge port 115 for supplying the washing water 43. By carrying out the backwashing step S24, the electrical conductivity ρ of the filtrate can be further reduced, and the halogen content, particularly the chlorine content, of the electrode catalyst precursor can be further reduced.

[0035] In the backwashing step S24, washing may be performed with water at room temperature (e.g., 23°C), but since the electrical conductivity ρ of the filtrate has decreased to some extent at the end of the forward washing step S23, it is preferable to perform washing with heated water (e.g., 70°C) from the beginning. The temperature of the heated water is preferably 60 to 80°C.

[0036] [Opening process] The plate-opening step S25 is a step of opening the filter plates 111, 111' that form the filter chamber 112, and is executed by the plate-opening step executing means 35. Fig. 7 is a diagram of one dehydrator 104 in the cleaning device 13 of Fig. 2, showing a preferred embodiment of the operating state in the plate-opening step S25. The plate-opening step executing means 35 drives the electric cylinder 105 to move the pressing member 106 toward the rear frame 102, thereby releasing the clamping of the dehydrator 104. In this way, the two filter plates 111, 111' of the dehydrator 104 are pulled apart, and the filter chamber 112 is opened.

[0037] [Cake removal process] The cake peeling step S26 is a step in which the filter cloth is lowered to peel off and drop the cake 40 containing the dehydrated electrode catalyst precursor, and is executed by the cake peeling step execution means 36. FIG. 8 is a diagram of one dehydrator 104 in the cleaning device 13 of FIG. 2, showing a preferred embodiment of the operating state in the cake peeling step S26. When the cake peeling step execution means 36 separates the two filter plates 111, 111' of the dehydrator 104 to a predetermined distance, the filter cloth 113 that has been holding the cake 40 containing the electrode catalyst precursor travels downward. In this way, the cake 40 containing the electrode catalyst precursor is automatically peeled off from the filter cloth 113.

[0038] [Filter cloth cleaning process] The filter cloth washing step S27 is a step of washing the filter cloth 113 with washing water 43 after the cake peeling step S26, and is executed by the filter cloth washing step execution means 37. FIG. 9 is a diagram of one dehydrator 104 extracted from the washing device 13 in FIG. 2, and shows a preferred embodiment of the operating state in the filter cloth washing step S27. After the cake 40 containing the electrode catalyst precursor is peeled off from the filter cloth 113, the filter cloth 113 travels upward and returns to its original position. The filter cloth washing step execution means 37 supplies washing water 43 from a washing water pipe 117 provided below the dehydrator 104 by a pump (not shown) for washing the filter cloth while the filter cloth 113 is traveling upward. The washing water 43 is sprayed onto the filter cloth 113 to wash the filter cloth 113, preventing clogging of the filter cloth 113 and reliably recovering the electrode catalyst precursor and the like attached to the filter cloth 113. That is, since the wastewater during the cleaning of the filter cloth contains the electrode catalyst precursor, it is preferable to recover all of it. In this way, the electrode catalyst precursor attached to the filter cloth 113 is washed by flowing it away, thereby increasing the yield of the electrode catalyst precursor. In addition, for example, the amount of electrode catalyst precursor recovered can be further increased by cleaning the filter cloth 113 while repeatedly running it up and down.

[0039] [Compression process] In addition, a squeezing step may be performed after the forward washing step S23 and / or after the reverse washing step S24. The squeezing step is a step of further squeezing and dehydrating the cake 40 containing the electrode catalyst precursor, and is performed by a squeezing step execution means (not shown). FIG. 10 is a diagram of one dehydrator 104 extracted from the washing device 13 of FIG. 2, and shows a preferred embodiment of the operating state in the squeezing step. The squeezing step execution means injects pressurized water 119 into a diaphragm 118 provided on one filter plate 111', thereby further squeezing and dehydrating the cake 40 containing the electrode catalyst precursor. The squeezing step increases the solid content concentration of the cake 40 containing the electrode catalyst precursor, and produces a cake 40 containing the electrode catalyst precursor with an extremely low moisture content. Here, if the pressurized water 119 is removed from the diaphragm 118 after the squeezing step is completed, the pressure from the diaphragm 118 is eliminated, and the filter cloth 113 that was pressed by the diaphragm 118 can be easily peeled off from the cake 40, which is preferable. In this squeezing step, the other filter plate 111 may also be provided with a diaphragm (not shown). In this case, pressurized water can also be injected into the diaphragm (not shown) provided on the filter plate 111 side, so that the cake 40 containing the electrode catalyst precursor can be squeezed and dehydrated. In this case, it is also preferable to configure the pressurized water to be released from the diaphragm after the squeezing step is completed, since the pressing force from the diaphragm (not shown) is eliminated, and the filter cloth 113 that was pressed by the diaphragm (not shown) can be easily peeled off from the cake 40.

[0040] Although one dehydrator 104 has been described above, according to the cleaning device 13 as shown in FIG. 2, all the dehydrators 104 can operate in the same way, so that the amount of material that can be processed at one time by one device can be increased, and the production efficiency of the electrode catalyst can be improved. In addition, since the above-mentioned dehydrator 104 has a large filtration area and a high pressure-resistant structure, the processing speed can be improved. Furthermore, since the process can be fully automated from the introduction of the raw solution to the discharge of the cake and the cleaning of the device, the effort and time required for the cleaning process can be reduced. Furthermore, since resins, lining materials, etc. can be selected as the material for the device, the corrosion resistance of the device can be improved.

[0041] [Electrical conductivity of the filtrate ρ] The processing conditions, such as the forward washing time of the forward washing step S23 and the reverse washing time of the reverse washing step S24, are adjusted so that the electrical conductivity ρ of the filtrate obtained after the forward washing step S23 and / or the reverse washing step S24, measured by the JIS standard test method (JIS K0522), is equal to or less than a preset value. For example, the cleaning effect is increased by lengthening the cleaning time of the reverse washing step to the same extent as the cleaning time of the forward washing step. 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 reverse washing step). In addition, the filtrate is a liquid discharged from a filtrate outlet after washing, and it is preferable to use all the filtrate discharged in that step.

[0042] The set value of the electrical conductivity ρ of the filtrate obtained after the forward cleaning step S23 is preferably a value selected from a range of 20 μS / cm or less. The set value of the electrical conductivity ρ of the filtrate obtained after the reverse cleaning step S24 is preferably a value selected from a range of 10 μS / cm or less. If the electrical conductivity ρ of the filtrate is 10 μS / cm or less, the concentrations of chlorine (Cl) species and bromine (Br) species contained in the electrode catalyst precursor are reduced to a level that allows practical use as an electrode catalyst for fuel cells.

[0043] The cleaning water 43 used in the cleaning device 13 may be pure water such as ultrapure water, but does not have to be pure water. i Ion-exchanged water or the like having a conductivity of less than 10 μS / cm can be used.

[0044] In this embodiment, a cleaning method and a filtration method using a filter press are adopted in the cleaning process, but a cleaning method and a filtration method using a conventional centrifuge (not shown) or the like may also be adopted.

[0045] (drying equipment) 11 shows a schematic configuration of the drying device 14 according to the present invention. The drying device 14 dries the electrode catalyst precursor cleaned by the above-mentioned cleaning device 13 using an agitation treatment device 201 equipped with an agitation blade 204. The agitation treatment device 201 as a drying device mainly includes a vessel body 202 in the form of an inverted cone-shaped hollow vessel, a decompression mechanism 203 for decompressing the inside of the vessel body 202, and the agitation blade 204. The vessel body 202 is covered at its upper part with a lid 205 that is detachably attached to the vessel body 202, a jacket 206 is provided on the peripheral wall through which steam S flows as a heating medium for heating the inside of the vessel body 202, and supports 210, 210 for supporting the vessel body 202 are provided on the outer surface. Load cells 212, 212 capable of checking changes in weight are provided on the undersides of the supports 210, 210, and the container body 202 is suspended at the installation location by installing the supports 210, 210 at the installation location via the load cells 212, 212. A stirring blade 204 is provided to stir the inside of the container body 202, a drive device 207 for the stirring blade 204 is provided on a lid 205 on the upper part of the container body 202, and an opening 208 for taking out the electrode catalyst precursor in the container body 202 is formed in the conical apex which is the lower end of the container body 202. A take-out valve 209 is provided in this opening 208, and the electrode catalyst precursor in the container body 202 is taken out by operating and opening the take-out valve 209. A supply port 211 is provided in the lid 205 on the upper part of the container body 202, and a supply valve 215 is provided in this supply port 211, and the electrode catalyst precursor is supplied to the container body 202 by operating and opening the supply valve 215. Further, the jacket 206 is provided with a heating medium inlet 213 for injecting steam S, and a heating medium outlet 214 for discharging steam S. The container body 202 is provided with a temperature indicating regulator 216, which monitors the temperature of the electrode catalyst precursor in the container body 202, and adjusts 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, thereby making it possible to adjust the temperature of the electrode catalyst precursor in the container body 202. Further, the heating medium inlet 213 is configured so that a cooling medium C can be injected in addition to the heating medium, and the heating medium outlet 214 is configured so that the cooling medium C can be discharged in addition to the heating medium.

[0046] 12 shows a perspective view of the stirring blade 204. The stirring blade 204 includes a main rotating shaft 222 extending through the center of the lid 205, a spiral ribbon rotor 223 attached to the tip of the main rotating shaft 222 and rotating together with the main rotating shaft 222, an arm 224 serving as a rotor support connecting the main rotating shaft 222 and the spiral ribbon rotor 223, and a vortex breaker 225 provided on the main rotating shaft 222 above the spiral ribbon rotor 223, and the main rotating shaft 222, the spiral ribbon rotor 223, the arm 224 and the vortex breaker 225 are integrally configured.

[0047] The rotating main shaft 222 is incorporated into the driving device 207 via a seal unit 221 (see FIG. 11), and by driving the driving device 207, the rotating main shaft 222 rotates, which in turn rotates the spiral ribbon rotor 223, the arm 224, and the vortex breaker 225 that are integral with the rotating main shaft 222. Therefore, the rotating main shaft 222 rotates the stirring blade 204 as the rotating main shaft 222 is rotated by the driving device 207. The rotating main shaft 222 is formed in a hollow tubular shape, and is connected to the arm 224, which is also formed in a hollow tubular shape, so that they can flow together. The end of the rotating shaft 222 on the drive unit 207 side is connected to a flow path for a gas G for the scraper, such as a flow path for nitrogen gas, normal pressure air, a mixed gas obtained by mixing nitrogen gas and oxygen gas in an arbitrary ratio to adjust the oxygen gas concentration, a mixed gas obtained by mixing nitrogen gas and air in an arbitrary ratio to adjust the oxygen gas concentration, or high pressure air, and is configured to inject the gas G into the rotating shaft 222, for example, by a gradual oxidation process execution means 54 or an extraction process execution means 55 described later.

[0048] 11, the driving device 207 uses a geared motor or the like, and is adapted to adjust the rotation speed to a predetermined value to rotate the stirring blade 204. The driving device 207 also includes 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, and is configured to be able to handle processing even when the inside of the container body 202 is at high vacuum or high pressure.

[0049] The spiral ribbon rotor 223 is formed in a spiral shape so that it is arranged with a small clearance along the inner wall surface of the conical container body 202 when the stirring blade 204 is arranged in the container body 202, and the electrode catalyst precursor rises along the inner wall surface of the container body 202 as the spiral ribbon rotor 223 rotates in the container body 202. In addition, the spiral ribbon rotor 223 is formed so that the ribbon width becomes wider toward the upper part, and is configured so that the powder transport in each cross section in the vertical direction of the container body 202 is at a constant ratio. Note that in this embodiment, as shown in FIG. 12, the spiral ribbon rotor 223 employs one single ribbon blade, but the spiral ribbon rotor 223 may employ two double ribbon blades.

[0050] 12, the arm 224 supports the spiral ribbon rotor 223, and securely fixes the spiral ribbon rotor 223 to the main rotating shaft 222. Furthermore, a gas ejection hole 226 for a scraper is provided on the underside of the tip of each arm 224, and when gas G is injected into the main rotating shaft 222 from the above-mentioned gas G flow path, the gas G is ejected from each gas ejection hole 226 through the inside of the main rotating shaft 222 and each arm 224, thereby preventing the electrode catalyst precursor from stagnation during the removal step S35 described below.

[0051] The vortex breaker 225 rotates within the container body 202, thereby directing 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 directed downward at the center of the container body 202, preventing classification caused by turbid currents on the layer surface during natural falling. 12, vortex current breaker 225 is arranged so as to leave a gap between it and the inner surface of lid 205. However, in the present invention, vortex current breaker 225 may be arranged integrally with and in contact with the inner surface of lid 205. Even in this case, the above-mentioned classification effect can be prevented.

[0052] Returning to FIG. 11, the decompression mechanism 203 will be described. Reference numeral 231 denotes a bag filter, which is provided in an exhaust hole 232 of the lid 205, and liquid and gas evaporated from the electrode catalyst precursor in the container body 202 are discharged through the bag filter 231. Reference numeral 233 denotes a condenser, which condenses the liquid flowing from the bag filter 231. The condenser 233 and the exhaust hole 232 of the lid 205 are connected by a connection pipe 235 through the bag filter 231. Reference numeral 234 denotes a vacuum pump, which is connected to the condenser 233 by a suction pipe 236, and is configured such that liquid and gas evaporated from the electrode catalyst precursor flow from the container body 202 to the bag filter 231 and the condenser 233 by driving the vacuum pump 234. Reference numeral 237 denotes a pressure indicating regulator 237, which regulates the pressure in the container body 202 when performing reduced pressure drying. A control valve 238 provided in the suction pipe 236 is adjusted by a control signal from a pressure indicating regulator 237 to adjust the degree of vacuum sucked by the vacuum pump 234. The gas and steam flowing from the bag filter 231 via the connection pipe 235 is condensed in the condenser 233, and components that are easy to condense are separated from the gas as condensed liquid. The separated gas is sucked into the vacuum pump 234 via the suction pipe 236 and exhausted from the vacuum pump 234. An air blow nozzle (not shown) may be provided at the bottom of the container body 202, and the container body 202 may be configured to return from a reduced pressure state to a normal pressure state by introducing an inert gas or air through the air blow nozzle.

[0053] As shown in the block diagram of Fig. 1 and the flow chart of Fig. 20, the drying device 14 includes an introduction step execution means 51, a drying step execution means 52, a cooling step execution means 53, a gradual oxidation step execution means 54, and an extraction step execution means 55, which are means for respectively executing an introduction step S31, a drying step S32, a cooling step S33, a gradual oxidation step S34 for subjecting the cooled electrode catalyst precursor to a gradual oxidation treatment, and an extraction step S35 for extracting the electrode catalyst precursor that has been gradual oxidized. Each of steps S31 to S35 will be described below.

[0054] [Introduction process] The introduction step S31 is a step of introducing the washed electrode catalyst precursor into the drying device 14, and is executed by the introduction step execution means 51. Explaining with reference to FIG. 13A, the introduction step execution means 51 operates and opens the supply valve 215 of the stirring processing device 201, and introduces the electrode catalyst precursor having a predetermined water content from the supply port 211 into the container body 202. It is preferable that the water content of the electrode catalyst precursor is measured in advance. The electrode catalyst precursor may be introduced by manual work using a funnel or the like, or may be directly introduced without human hands from a pipe or belt conveyor through which the electrode catalyst precursor is transported, as shown in FIG. 13A. Here, the weight of the introduced electrode catalyst precursor is measured by the load cells 212, 212. Note that, before this introduction step S31, a preheating step of preheating the inside of the container body 202 to a predetermined temperature by injecting steam S into the jacket 206 may be performed. Thereafter, the introduction step execution means 51 operates the supply valve 215 to close it and seal the container body 202, completing the introduction step S31.

[0055] [Drying process] The drying step S32 is a step of drying the electrode catalyst precursor introduced into the container body 202 (a step of performing so-called vacuum drying), and is executed by the drying step execution means 52. Explained with reference to Fig. 13B together with Fig. 11 etc., the drying step execution means 52 drives the drive device 207 to rotate the stirring blade 204, drives the vacuum pump 234 to evacuate and reduce the pressure inside the container body 202, and adjusts the operating pressure to a predetermined pressure with the pressure indicating regulator 237 to stir and mix the electrode catalyst precursor. The rotation speed of the stirring blade 204 is preferably 40 to 80 revolutions per minute, and the operating pressure is preferably 5 to 20 kPa (gauge pressure). Furthermore, the drying process execution means 52 injects steam S from the heating medium inlet 213 into the jacket 206 using the temperature indicating regulator 216, and heats the vessel body 202 by the conductive heat transfer of the steam S, thereby adjusting the electrode catalyst precursor in the vessel body 202 to a predetermined temperature (drying temperature) and drying it. Furthermore, heat generated by stirring with the stirring blades 204 contributes to drying the electrode catalyst precursor. The drying temperature is preferably set to a value selected from the range of 50 to 150°C. The operating pressure and heating temperature may be changed during the drying process to adjust the drying time by measuring the temperature (product temperature) of the electrode catalyst precursor and observing the degree of change in the product temperature.

[0056] To explain in more detail the circulating flow of the electrode catalyst precursor inside the container body 202 in the drying step S32, the rotation of the stirring blade 204 causes the electrode catalyst precursor to rise along the inner wall surface of the container body 202. Thereafter, when the electrode catalyst precursor is brought to the center of the container body 202 by the vortex breaker 225 provided above the spiral ribbon rotor 223, it immediately descends from this center and sinks into the layer, thus circulating.

[0057] The vapor and gas evaporated from the electrode catalyst precursor are sucked by the vacuum pump 234, and dust is filtered and collected by the bag filter 231. Thereafter, the vapor and gas flow through the connection pipe 235 to the condenser 233, where they are cooled and condensed and liquefied, and the condensed liquid is collected, and the gas is exhausted by the vacuum pump 234. The vapor and gas evaporate from the electrode catalyst precursor in this way, and the weight of the electrode catalyst precursor changes. The weight of the electrode catalyst precursor in the container body 202 at this time is measured by the load cells 212, 212, and the current moisture content of the electrode catalyst precursor is calculated from the weight and moisture content of the electrode catalyst precursor at the time of introduction and the current weight of the electrode catalyst precursor. The drying step S32 is completed when the electrode catalyst precursor in the container body 202 becomes equal to or less than a predetermined moisture content. The predetermined moisture content is preferably 3 wt%. Hereinafter, the value of the moisture content is described in terms of wet base. In the present invention, the load cell 212 may not be included. In this case, the change in weight of the electrode catalyst precursor in the container body 202 may be grasped in advance by performing a preliminary test under the same drying conditions (weight of electrode catalyst precursor put into the container body 202, drying conditions) in the drying step S32. Then, the change in weight of the electrode catalyst precursor in the container body 202 may be easily grasped by monitoring the elapsed time from the start of drying based on the results of the preliminary test.

[0058] [Cooling process] The cooling step S33 is a step of cooling the electrode catalyst precursor dried in the vessel body 202, and is executed by the cooling step execution means 53. Explained in FIG. 13C with reference to FIG. 11 and the like, the cooling step execution means 53 discharges the steam S in the jacket 206 from the heating medium discharge port 214 by the temperature indicating regulator 216. Here, the cooling step execution means 53 continues to drive the drive device 207 and the vacuum pump 234, rotates the stirring blade 204, and evacuates and reduces the pressure inside the vessel body 202, thereby continuing the stirring and mixing of the electrode catalyst precursor. At this time, the rotation speed of the stirring blade 204 is preferably 40 to 80 revolutions per minute, and the operating pressure during the reduction in pressure is preferably atmospheric pressure. Furthermore, the cooling process execution means 53 injects the cooling medium C from the heating medium outlet 214 into the jacket 206 using the temperature indicating regulator 216, and cools the container body 202 by conductive heat transfer of the cooling medium, thereby cooling the electrode catalyst precursor in 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 preferably a value not higher than 40°C, preferably selected from the range of 10 to 40°C. The cooling process is completed when the cooling process execution means 53 detects by the temperature indicating regulator 216 that the electrode catalyst precursor has reached the predetermined temperature.

[0059] [Slow oxidation process] The gradual oxidation step S34 is a step of subjecting the electrode catalyst precursor cooled in the container body 202 to a gradual oxidation treatment, and is executed by the gradual oxidation step execution means 54. The gradual oxidation step execution means 54 discharges the cooling medium C in the jacket 206 from the heating medium inlet 213, stops the driving device 207 and the vacuum pump 234, and operates the supply valve 215 to gradually return the pressure in the container body 202 to normal pressure, thereby gradually oxidizing the dried electrode catalyst precursor. In addition, when the gas G for the scraper is high-pressure air, the gradual oxidation step execution means 54 may be configured to inject the high-pressure air from the flow path of the gas G for the scraper into the rotating main shaft 222 and to spray the high-pressure air from each gas ejection hole 226 to gradually return the pressure in the container body 202 to normal pressure. In addition, when an air blow nozzle is provided at the bottom of the container body 202, the gradual oxidation step execution means 54 may be configured to gradually return the pressure in the container body 202 to normal pressure by the air blow nozzle. When the gradual oxidation treatment of the electrode catalyst precursor in the container body 202 is completed, the gradual oxidation step is completed. In addition, in the gradual oxidation process S34, when the pressure inside the container body 202 is gradually returned to normal pressure and the inside of the container body 202 is finally returned to an air atmosphere at normal pressure, a mixed gas in which nitrogen gas and oxygen gas are mixed in an arbitrary ratio to adjust the oxygen gas concentration, or a mixed gas in which nitrogen gas and air are mixed in an arbitrary ratio to adjust the oxygen gas concentration, is ejected from each gas ejection hole 226, and the oxygen gas concentration inside the container body 202 is increased over time while being controlled within a numerical range experimentally determined in advance so that the electrode catalyst precursor does not ignite during this process, and finally the oxygen concentration is made the same as that of air.

[0060] [Removal process] The removal step S35 is a step of removing the electrode catalyst precursor cooled in the container body 202, and is executed by the removal step execution means 55. Explaining FIG. 13D with reference to FIG. 11 and the like, the removal step execution means 55 operates and opens the removal valve 209, thereby removing the electrode catalyst precursor from the container body 202 through the opening 208. Since the internal structure of the container body 202 of the stirring processing device 201 is simple, the residual powder of the electrode catalyst precursor can be reduced during the removal step S35. In addition, at this time, the removal step execution means 55 performs a scraper step in which gas G is injected from the passage of the gas G for the scraper into the rotating main shaft 222 and gas G is sprayed downward from each gas ejection hole 226, thereby blowing the electrode catalyst precursor attached to the inner wall of the container body 202 and the stirring blade 204 downward, and increasing the recovery rate of the electrode catalyst precursor. The removal step is completed when all of the electrode catalyst precursor inside the container body 202 has been removed.

[0061] <Catalyst for electrode> The structure of the electrode catalyst produced in this embodiment is not particularly limited, and may be a structure in which precious metal catalyst particles are supported on a conductive support (conductive carbon support, conductive metal oxide support, etc.). For example, it may be a so-called Pt catalyst, a Pt alloy catalyst (PtCo catalyst, PtNi catalyst, etc.), or a so-called core-shell catalyst having a core-shell structure. For example, in the case of a core-shell catalyst having a configuration in which palladium is used as the constituent element of the core portion 4 and platinum is used as the constituent element of the shell portion 5, materials containing chlorine (Cl) species such as chloride salts of platinum (Pt) and chloride salts of palladium (Pd) are often used as raw materials. According to the manufacturing system and manufacturing method of the electrode catalyst of this embodiment, it is possible to manufacture an electrode catalyst with a reduced content of these chlorine (Cl) species.

[0062] An example of the structure of an electrode catalyst will be described in more detail with reference to the drawings. As shown in Fig. 14, an electrode catalyst 1 having a core-shell structure includes a carrier 2 and a catalyst particle 3 supported on the carrier 2. The catalyst particle 3 includes a core portion 4 and a shell portion 5 formed so as to cover at least a part of the core portion 4. The catalyst particle 3 has a so-called core-shell structure including the core portion 4 and the shell portion 5 formed on the core portion 4.

[0063] That is, the electrode catalyst 1 has catalyst particles 3 supported on a carrier 2, and the catalyst particles 3 have a structure in which a core portion 4 serves as a nucleus (core) and a shell portion 5 serves as a shell that covers the surface of the core portion 4. In addition, the constituent elements (chemical composition) of the core portion 4 and the constituent elements (chemical composition) of the shell portion 5 have different compositions.

[0064] Further, as a specific example of the core-shell structure, in FIG. 15, an electrode catalyst 1A has a catalyst particle 3a composed of a core portion 4, a shell portion 5a covering a part of the surface of the core portion 4, and a shell portion 5b covering another part of the surface of the core portion 4. In addition, in FIG. 16, an electrode catalyst 1B has a catalyst particle 3 composed of a core portion 4 and a shell portion 5 covering almost the entire surface of the core portion 4, and the shell portion 5 has a two-layer structure including a first shell portion 6 and a second shell portion 7. Furthermore, in FIG. 17, an electrode catalyst 1C has a catalyst particle 3a composed of a core portion 4, a shell portion 5a covering a part of the surface of the core portion 4, and a shell portion 5b covering another part of the surface of the core portion 4, and the shell portion 5a has a two-layer structure including a first shell portion 6a and a second shell portion 7a, and the shell portion 5b has a two-layer structure including a first shell portion 6b and a second shell portion 7b.

[0065] In this embodiment, the chlorine (Cl) species refers to a chemical species containing chlorine as a constituent element. Specifically, the chemical species containing chlorine include chlorine atoms (Cl), chlorine molecules (Cl), and chloride ions (Cl - ), chlorine radical (Cl·), polyatomic chloride ions, and chlorine compounds (such as X-Cl, where X is a counterion).

[0066] In this embodiment, the bromine (Br) species refers to a chemical species containing bromine as a constituent element. Specifically, the chemical species containing bromine include bromine atoms (Br), bromine molecules (Br), bromide ions (Br - ), the bromine radical (Br ), polyatomic bromide ions, and bromine compounds (such as X-Br, where X is a counterion).

[0067] <Method of manufacturing electrode catalyst> 18, the manufacturing method of the electrode catalyst according to this embodiment includes an electrode catalyst precursor manufacturing step S1 for manufacturing an electrode catalyst precursor, which is a raw material of the electrode catalyst, a washing step S2 for washing the liquid 30 containing the electrode catalyst precursor manufactured in the electrode catalyst precursor manufacturing step S1 by a filter press, and a drying step S3 for drying the electrode catalyst precursor washed in the washing step S2 by an agitation processing device 201 equipped with an agitation blade 204 having a spiral ribbon rotor 223. Each of the steps S1, S2, and S3 can be performed by the electrode catalyst precursor manufacturing device 12, the filter press as the washing device 13, and the agitation processing device 201 as the drying device 14 of the electrode catalyst manufacturing system 10 described above, respectively.

[0068] As shown in Fig. 19, the cleaning step S2 includes a plate closing step S21, a press-in step S22, a forward cleaning step S23, a reverse cleaning step S24, a plate opening step S25, a cake peeling step S26, and a filter cloth cleaning step S27. In the cleaning step S2, the electrode catalyst precursor-containing liquid 30 produced in the electrode catalyst precursor production step S1 is cleaned, filtered, and dehydrated to obtain the electrode catalyst precursor 41 after cleaning. In addition, a squeezing step may be performed after the forward cleaning step S23 and / or after the reverse cleaning step S24. The configuration of each step S21 to S27 and the squeezing step is as described in the above-mentioned <electrode catalyst production system> (cleaning device).

[0069] As shown in Fig. 20, the drying step S3 includes an introduction step S31, a drying step S32, a cooling step S33, a gradual oxidation step S34, and a removal step S35. In the drying step S3, the electrode catalyst precursor washed in the washing step S2 is dried to obtain a dried electrode catalyst 1. The configuration of each step S31 to S35 is as described above in <Electrode catalyst manufacturing system> (drying device).

[0070] The examples described herein are illustrative of embodiments of the invention and should not be construed as limiting the scope of the invention.

[0071] <Production of electrode catalyst precursor (reaction process, electrode catalyst precursor production step)> (Production Example 1) [Preparation of liquid (stock solution) containing electrode catalyst precursor] A Pt particle-supported carbon catalyst (hereinafter referred to as "Pt / C catalyst", manufactured by NECHEMCAT, Pt loading rate 50 wt%, product name: "SA50BK") was used as the electrode catalyst. First, a liquid containing its precursor was prepared. The carrier for this precursor was a commercially available conductive hollow carbon carrier {manufactured by Lion Corporation, trade name "Carbon ECP" (registered trademark) (Ketjen Black EC300J), specific surface area 750 to 800 m2}. 2 / g} was used. The carrier and the water-soluble Pt salt were dispersed in water. Next, a water-soluble reducing agent was added to the dispersion containing the carrier and the water-soluble Pt salt, and the reduction reaction of the Pt component was allowed to proceed at a predetermined temperature. In this way, a liquid containing the electrode catalyst precursor used in this embodiment was prepared.

[0072] The liquid containing the electrode catalyst precursor obtained as described above was dispersed in a kettle without being dried, and used as a stock solution to be treated in a cleaning device.

[0073] <Production of electrode catalyst> Example 1 [Processing using cleaning equipment (cleaning step)] The liquid containing the electrode catalyst precursor obtained in Production Example 1 was introduced into a cleaning device, and a cleaning process was carried out. The processing time for each process in the cleaning device is shown in Table 1. First, the pressing process was carried out for 20 minutes. The thickness of the cake containing the electrode catalyst precursor in the pressing process was set to 5 to 10 mm.

[0074] The thickness of this cake is within a range of thickness that is previously determined through preliminary experiments, taking into consideration the degree of cleaning and cleaning time required for the electrode catalyst precursor to be used.

[0075] Next, the forward washing step was carried out. In the forward washing step, the filtrate was first treated with washing water at room temperature (23°C) for 24 minutes, and when the electrical conductivity ρ of the filtrate became 40 μS / cm or less, the water was switched to heated water (70°C) and treated with heated water for 50 minutes. After the forward washing step, a squeezing step was carried out for 5 minutes. Then, a reverse washing step was carried out, and in the reverse washing step, the filtrate was treated with heated water (70°C) for 73 minutes. The washing process was carried out for a total of about 2.9 hours.

[0076] Ion-exchanged water was used for washing. The electrical conductivity of the ion-exchanged water used at room temperature (23°C) was i is 7.70μS / cm, and electrical conductivity ρ when heated (70℃) i is 4.6μS / cm.

[0077] [Treatment using a drying device (drying step)] The cake containing the electrode catalyst precursor obtained after the treatment by the cleaning device was introduced into the stirring treatment device 201 as a drying device, and a drying step S3 was carried out. In this Example 1, since the cake containing the electrode catalyst precursor is dried using the stirring treatment device 201 having a stirring mechanism, there is no need to crush the cake containing the electrode catalyst precursor (coarsely crushing the cake before introducing it into a tray vacuum dryer) as performed in Comparative Example 1 described later. That is, the crushing step in Comparative Example 1 described later is not necessary. The processing time for each step in the agitation processing device 201 is shown in Table 2. In the introduction step S31, the capacity of the agitation device 201 was selected based on the powder surface height in the container body 202 of the agitation device 201 when 52 kg of cake was charged, and an agitation device 201 was adopted in which the effective capacity of the container body 202 was 100 L and the spiral ribbon rotor 223 was a single ribbon blade. First, in an introduction step S31, cake loading was performed in which 52 kg of cake having a moisture content of about 82% was loaded into the container body 202. Thereafter, a drying step S32, a cooling step S33, and a gradual oxidation step S34 were carried out in this order, and the cake was taken out in a removal step S35, and the time required to obtain an electrode catalyst with a moisture content of 3 wt % or less was measured. Furthermore, in order to confirm whether the "friction" caused by the stirring and drying would have any effect on the product, in the cooling step S33, the stirring blade 204 was rotated while the cooling medium C was injected into the jacket 206 from the heating medium outlet 214, and a stirring test was performed with the electrode catalyst precursor while cooling.

[0078] Comparative Example 1 [Processing using cleaning equipment (cleaning step)] The liquid containing the electrode catalyst precursor obtained in Production Example 1 was introduced into a cleaning device, and a cleaning process was carried out. The processing time for each process in the cleaning device is shown in Table 1. First, the pressing process was carried out for 40 minutes. The thickness of the cake containing the electrode catalyst precursor in the pressing process was set to 11 to 15 mm.

[0079] The thickness of this cake is in a range outside the range of thicknesses previously determined by preliminary experiments, taking into consideration the degree of cleaning and cleaning time required for the electrode catalyst precursor to be used.

[0080] Next, the forward washing step was carried out. In the forward washing step, the mixture was first treated with room temperature (23°C) washing water for 33 minutes, and when the electrical conductivity ρ of the filtrate became 40μS / cm or less, the water was switched to heated water (70°C) and treated with heated water for 60 minutes. After the forward washing step, the squeezing step was carried out for 5 minutes, followed by the reverse washing step. However, since the electrical conductivity ρ of the filtrate did not change from the electrical conductivity ρ of the filtrate at the end of the forward washing step, the reverse washing step was carried out for 36 minutes, i.e., after a total of about 2.9 hours of washing, the treatment was interrupted.

[0081] Ion-exchanged water was used for washing. The electrical conductivity of the ion-exchanged water used at room temperature (23°C) was i is 7.70μS / cm, and electrical conductivity ρ when heated (70℃) i is 4.6μS / cm.

[0082] [Treatment using a drying device (drying step)] The cake containing the electrode catalyst precursor obtained after the treatment with the washing device was subjected to a drying step using a dedicated crusher, a tray vacuum dryer, and a hammer mill. First, the cake was crushed using a dedicated crusher to obtain 52 kg of electrode catalyst precursor with a moisture content of approximately 80-82%. In this crushing step, the cake is removed from the cleaning device, and the cake containing the electrode catalyst precursor is crushed (coarsely crushed before being introduced into the tray vacuum dryer). Unlike the stirring treatment device 201 in Example 1, the tray vacuum dryer used in this Comparative Example 1 is not equipped with a stirring mechanism, so a crusher is used to roughly crush the cake before being introduced into the tray vacuum dryer, and the crushed cake must be distributed approximately evenly on the shelves. In the subsequent introduction process, this electrode catalyst precursor was arranged in a cake arrangement onto 20 trays measuring 600 mm in width, 780 mm in length, and 20 mm in height. The trays onto which the electrode catalyst precursor was arranged were then placed into a shelf vacuum dryer, the door was closed, and a drying process was performed in which the electrode catalyst precursor was dried under reduced pressure, and a cooling process was performed in which the electrode catalyst precursor was cooled under reduced pressure. After the cooling step, a gradual oxidation step was carried out by slowly opening the door, and in the subsequent unloading step, the tray was removed from the tray vacuum dryer to unload the electrode catalyst precursor. Thereafter, the extracted electrode catalyst precursor was subjected to a pulverization step in which it was pulverized with a hammer mill, and the time required to obtain an electrode catalyst having a water content of 3 wt % or less was measured. Unlike the stirring treatment device 201 of Example 1, the tray vacuum dryer used in this Comparative Example 1 is not equipped with a stirring mechanism, and therefore it becomes necessary to pulverize the lumps of electrode catalyst precursor powder using a hammer mill. In addition, it becomes necessary to remove the lumps of electrode catalyst precursor powder from the tray vacuum dryer before pulverization with the hammer mill.

[0083] [Table 1]

[0084] <Evaluation Results> As shown in Table 1, in Example 1, the electrical conductivity ρ of the filtrate at the end of the forward cleaning step was 15.9 μS / cm, whereas the electrical conductivity ρ of the filtrate at the end of the reverse cleaning step was reduced to 9.7 μS / cm. The electrical conductivity ρ of the filtrate could be reduced to 10 μS / cm or less in a cleaning treatment time of less than 3 hours. On the other hand, in Comparative Example 1, the electrical conductivity ρ of the filtrate at the end of the forward cleaning step was reduced to 19.3 μS / cm, but did not decrease at all from 19.3 μS / cm even after the reverse cleaning step was performed thereafter.

[0085] [Table 2]

[0086] <Evaluation Results> As shown in Table 2, in Example 1, there was no need to arrange the electrode catalyst precursor in the introduction step S31, and the electrode catalyst precursor was simply loaded into the container body 202, so the time required was reduced from 2 hours in Comparative Example 1 to 0.4 hours. In Example 1, the drying process S32 and the cooling process S33 had a higher drying speed than the tray vacuum dryer due to the high mixing capacity and heat transfer from the jacket 206, and the drying time was reduced from 24 hours required in Comparative Example 1 to 3.1 hours. Here, it was confirmed that the obtained electrode catalyst was almost comparable to that of Comparative Example 1, and that the "friction" caused by the stirring and drying had almost no effect on the product quality. Furthermore, in Example 1, no time reduction was confirmed in the gradual oxidation step S34 and the extraction step S35 compared to Comparative Example 1, while in Example 1, the crushing step and the pulverization step could be omitted.

[0087] Comparative Example 2 [Processing using cleaning equipment (cleaning step)] The liquid containing the electrode catalyst precursor obtained in Production Example 1 was introduced into a centrifuge and washed. Washing was repeated until the electrical conductivity ρ of the filtrate measured by JIS standard test method (JIS K0522) was 10 μS / cm or less, and the obtained electrode catalyst precursor was dispersed in ultrapure water to prepare a dispersion, and the dispersion was filtered. The residue obtained by filtration was dried in a dryer at a temperature of 70° C. in air for 24 hours to obtain an electrode catalyst. Table 3 shows a comparison of the processing times (washing step) using the washing devices in Example 1 and Comparative Example 2. In Table 2, the processing time from the raw material feed to solid-liquid separation is shown separately from the time required for cake washing and dehydration.

[0088] [Table 3]

[0089] <Evaluation Results> In Comparative Example 2, in which washing was carried out using a conventional centrifuge, it took 15 to 19 hours to reduce the electrical conductivity ρ of the filtrate to 10 μS / cm or less after three attempts.

[0090] Therefore, as can be seen from a comparison between Example 1 and Comparative Examples 1 and 2, the electrode catalyst manufacturing system and manufacturing method of this embodiment can significantly reduce the time required for processing by the cleaning device (cleaning step) to 1 / 5 or less compared to processing using a conventional centrifuge. Furthermore, in the cleaning device according to this embodiment, the cake containing the electrode catalyst precursor is automatically peeled off, eliminating the need for an operator to scrape off the electrode catalyst precursor, and significantly reducing the effort required.

[0091] As will be understood when comparing Example 1 with Comparative Example 1, the manufacturing system and method for an electrode catalyst according to this embodiment can significantly reduce the time required for the treatment (drying step S3) by the drying device 14 to about 1 / 5 to about 1 / 6. Furthermore, the stirring device 201 as the drying device 14 according to this embodiment can automatically perform the drying step S32, the cooling step S33, the gradual oxidation step S34, and the removal step S35, so that the labor can be significantly reduced, and it is possible to provide a manufacturing method and a manufacturing system for an electrode catalyst that involves as little manual work as possible. EXAMPLES

[0092] <Electrode catalyst manufacturing system> 21 is a block diagram showing an outline of an electrode catalyst manufacturing system according to the second embodiment. In addition to the electrode catalyst precursor manufacturing apparatus 12, the cleaning apparatus 13, and the drying apparatus 14 described in the first embodiment, the electrode catalyst manufacturing system 150 further includes an analyzer 151 that analyzes the physical properties of the electrode catalyst 1 after drying and a wet product after preparing a catalyst cake, and a reactor 152 that mixes ion-exchanged water with the electrode catalyst 1 after drying to reslurry it.

[0093] Conventionally, concerns about the ignition and loss of powdered electrode catalysts have been an issue when packaging powdered electrode catalysts for shipment and when weighing electrode catalysts when used by customers. As a measure against ignition and loss of electrode catalysts and in future packaging and delivery forms, it is expected that electrode catalysts will be supplied as wet products, in which the powder is wetted with pure water, and demand is expected to increase in the future. However, for example, if the weight ratio of electrode catalyst to water is 1:4, the wet product will not become solid but will become liquid. Electrode catalysts are expensive and need to be recovered as much as possible, but the wet product will remain attached to the device or the container that contains the electrode catalyst, and will dry out and adhere to the inner walls of the container. A method of extracting a wet product with a desired weight ratio of electrode catalyst:water in the drying step S32 of the first embodiment is also devised, but in this case, the wet product is in a state that has not been subjected to the gradual oxidation step S34, and there is a risk that the oxidation state of the catalyst particle surface of the electrode catalyst cannot be made sufficiently stable in the atmosphere, and the electrode catalyst may have a different initial activity for the hydrogen oxidation reaction and the oxygen reduction reaction. In this case, since the electrode catalyst precursor is only washed and filtered in the washing step S2, there is a possibility that the uniformity of the moisture content of the wet product may become uneven. For these reasons, supplying the wet product has difficulties in handling and recovery both at the manufacturer and at the supply destination to the customer.

[0094] Therefore, in this embodiment, the electrode catalyst precursor after cleaning is dried to make the oxidation state of the catalyst particle surface of the electrode catalyst sufficiently stable in the atmosphere. In addition, ion-exchanged water is mixed with the electrode catalyst 1 after drying, and the water content of the slurry containing the electrode catalyst is made uniform, and then it is dried to a level where it can be made into a solid (pellet-like, cake-like). As a result, the water content of the WET product is adjusted to a target numerical range to prepare multiple solid catalyst cakes, and by supplying the WET product with a desired weight ratio, the risk of ignition and loss of the powdered catalyst is reliably prevented, and the handling and recovery are improved at both the manufacturer and the customer destination. In addition, with regard to the solid catalyst cake, during the catalyst synthesis process, the surface of the catalyst carrier is subjected to various chemical actions from each reagent used in the synthesis, and the products, by-products, and impurities generated in each synthesis reaction. As a result, the type, total amount, and amount per unit area of ​​the surface functional groups of the catalyst carrier differ. As a result, the affinity (wettability) of the catalyst to water changes depending on the type of catalyst (type of carrier) and the type of synthesis reaction process used. Therefore, the water content (range of water content) at which a solid state having excellent handleability and recoverability can be obtained must be experimentally determined in advance for each catalyst.

[0095] (Analyzer) The analyzer 151 performs a physical property analysis of the electrode catalyst 1 obtained through the drying step S3 of the first embodiment. The analyzer 151 includes a first physical property analysis execution means 153 that executes a first physical property analysis step S36 of the electrode catalyst 1 taken out in the take-out step S35 of the first embodiment. In this first physical property analysis step S36, it is preferable to analyze at least the catalyst loading amount, water content (wt%), and catalyst particle size of the electrode catalyst 1. Note that in this embodiment, a method is adopted in which a portion of the powder of the electrode catalyst 1 taken out in the take-out step S35 is extracted and the physical properties are analyzed by the analyzer 151, but other analysis methods may be used.

[0096] (Reactor) The reactor 152 reslurries the electrode catalyst 1 dried in the drying device 14 after the first physical property analysis step S36. In this embodiment, the electrode catalyst 1 is reslurried using the reactor 152, and while this requires one more piece of equipment, it allows the electrode catalyst 1 to be reslurried more quickly and reliably. The reactor 152 includes a reslurry step execution means 154 that executes a reslurry step S40 for reslurrying the electrode catalyst 1 taken out in the take-out step S35. As a method for reslurrying in the reslurry step S40, a method for reslurrying using a reactor equipped with a stirring device, for example, a kettle equipped with a stirrer, can be adopted.

[0097] As shown in the block diagram of Fig. 21 and the flow chart of Fig. 22, the reslurry step execution means 154 includes an introduction step execution means 156, a mixing step execution means 157, and an extraction step execution means 158, which are means for respectively executing an introduction step S41, a mixing step S42, and an extraction step S43. In this embodiment, in order to keep the oxidation state of the catalyst particle surface of the electrode catalyst used stable in the atmosphere, each step S41 to S43 is performed at room temperature, at atmospheric pressure, and in the atmosphere, and a special gas atmosphere such as nitrogen is not used. Each step S41 to S43 will be described below.

[0098] [Introduction process] The introduction step S41 is a step of introducing the electrode catalyst 1 dried by the drying device 14 and ion-exchanged water for mixing into the reactor 152, and is executed by the introduction step execution means 156. The method of introducing the electrode catalyst 1 and the ion-exchanged water may be manual introduction using a funnel or the like, as in the introduction step S31, or the electrode catalyst 1 and the ion-exchanged water may be directly introduced without human intervention by providing the reactor 152 with a pipe, a belt conveyor, or the like for transporting the electrode catalyst 1 and the ion-exchanged water.

[0099] As for the ion-exchanged water, pure water can be used, and it is preferable to use "ultrapure water." "Ultrapure water" is defined as: R = 1 / ρ (1) The resistivity R (the reciprocal of the electrical conductivity measured by the JIS standard test method (JIS K0552)) represented by the formula above is 3.0 MΩ·cm or more. In the above formula (1), R represents resistivity, and ρ represents electrical conductivity measured by the JIS standard test method (JIS K0552). The "ultrapure water" is preferably of a clean water quality equivalent to or higher than the water quality of "A3" specified in JIS K0557 "Water for use in testing water and wastewater", but is not particularly limited as long as it has an electrical conductivity that satisfies the relationship represented by formula (1). For example, ultrapure water produced using an ultrapure water production apparatus such as "Milli Q series" (manufactured by Merck Ltd.) or "Elix UV series" (manufactured by Nihon Millipore K.K.) may be used as the "ultrapure water". The ion-exchanged water does not necessarily have to be pure water, and for example, ion-exchanged water having a pH of 6 to 8 and an electrical conductivity ρi of less than 10 μS / cm measured according to the JIS standard test method (JIS K0522) can also be used.

[0100] The weight ratio of the electrode catalyst 1 and the ion-exchanged water introduced in the introduction step S41 is preferably such that the mixture of the electrode catalyst 1 and the ion-exchanged water becomes a liquid slurry, and for example, the weight ratio of the electrode catalyst:ion-exchanged water is experimentally determined to be optimal depending on the catalyst type from within a range of 1:2 to 1:3.5. In this embodiment, the amount of the ion-exchanged water to be introduced is calculated and determined from the results of the physical property analysis of the electrode catalyst 1, such as the catalyst loading amount and water content, and the amount of the electrode catalyst 1 to be introduced. The amount of the electrode catalyst 1 to be introduced may be measured manually, or the weight of the electrode catalyst 1 may be measured by the load cells 212, 212 at the start and end of the removal step S35 in the first embodiment, and the amount of the electrode catalyst 1 may be calculated using the results.

[0101] [Mixing process] The mixing step S42 is a step of mixing the introduced electrode catalyst 1 and ion-exchanged water in the reactor 152, and is executed by the mixing step execution means 157. The mixing step execution means 157 drives the agitator of the reactor 152 to agitate and mix the electrode catalyst 1 and ion-exchanged water at room temperature and atmospheric pressure. In this embodiment, the ratio of the electrode catalyst 1 and the ion-exchanged water is such that the mixture becomes a liquid slurry, so that the electrode catalyst 1 is not likely to ignite or disappear during mixing even at room temperature and atmospheric pressure, and the mixture can be agitated and mixed more uniformly. The mixing step S42 is completed when the electrode catalyst 1 and the ion-exchanged water are mixed and become uniform, and a slurry 159 containing the electrode catalyst is prepared. The driving time and rotation speed of the agitator will not be described in detail here because they vary depending on the capacity and type of the reactor 152, the amount of the introduced electrode catalyst 1 and ion-exchanged water, etc.

[0102] [Removal process] The removal step S43 is a step of removing the slurry 159 containing the electrode catalyst prepared in the reactor 152, and is executed by the removal step execution means 158. Thereafter, the removed slurry 159 containing the electrode catalyst is introduced again into the drying device 14. Therefore, when the slurry 159 containing the electrode catalyst is introduced into the drying device 14 by manual work, the slurry 159 containing the electrode catalyst may be temporarily removed into another container or the like. When the slurry 159 containing the electrode catalyst is directly introduced into the drying device 14 without manual work, a pipe or the like may be connected to the drying device 14, and the slurry 159 containing the electrode catalyst may be transferred from the reactor 152 to the drying device 14 through the pipe or the like. The removal step S43 is completed when all of the slurry 159 containing the electrode catalyst in the reactor 152 is removed. The removal step execution means 158 differs depending on the type of the reactor 152, and will not be described in detail here.

[0103] (drying equipment) The drying device 14 dries the slurry 159 containing the electrode catalyst reslurried in the reslurry step S40 with an agitation treatment device 201 equipped with an agitation blade 204 to prepare a plurality of solid catalyst cakes. The drying device 14 used in this step may be the drying device 14 used in the drying step S3 in the first embodiment, or may be another drying device 14. The structure of the agitation treatment device 201 as a drying device is similar to that in the first embodiment, and therefore a description thereof will be omitted.

[0104] The catalyst cake preparation step S50 for preparing a solid catalyst cake includes, similarly to the drying step S3 in the first embodiment, an introduction step S31', a drying step S32', a cooling step S33', a gradual oxidation step S34' for subjecting the cooled wet product to a gradual oxidation treatment, and an unloading step S35' for unloading the wet product that has been subjected to the gradual oxidation treatment. The operating conditions of each step S31'-S35' are the same as those of each step S31-S35 in the drying step S3 in the first embodiment, and therefore the main actions of each step S31'-S35' are the same as those of each step S31-S35 in the drying step S3 in the first embodiment.

[0105] In the drying step S32', steam and gas evaporate from the slurry 159 in the container body 202, and the weight of the slurry 159 changes. The weight of the slurry 159 in the container body 202 at this time is measured by the load cells 212, 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 the electrode catalyst 1 to the ion-exchanged water determined in the introduction step S41, and the current weight of the slurry 159. The drying step S32' is completed when the slurry 159 in the container body 202 becomes a predetermined moisture content or less and becomes a solid (pellet-like, cake-like) wet product. In this way, the slurry 159 with a uniform moisture content is dried to prepare a wet product of the catalyst cake, and the moisture content of this wet product can be made uniform. Here, the predetermined moisture content is preferably less than 80 wt%, so that the wet product does not stick to the container body 202 or the stirring blade 204.

[0106] In the gradual oxidation step S34', similarly to the drying step S3, the cooling medium C in the jacket 206 is discharged from the heating medium inlet 213, the drive unit 207 and the vacuum pump 234 are stopped, and the supply valve 215 is operated to gradually return the pressure in the vessel body 202 to normal pressure, thereby gradually oxidizing the wet catalyst cake. Therefore, compared with the conventional box-type shelf vacuum dryer, the operation time can be significantly shortened and automated. Furthermore, since the gradual oxidation step S34' can also be automated, the gradual oxidation step can be carried out more reliably. The gradual oxidation step is completed when the gradual oxidation treatment of the wet catalyst cake in the vessel body 202 is completed.

[0107] (Analyzer) The analysis device 151 performs a physical property analysis of the wet product obtained through the catalyst cake preparation step S50. The analysis device 151 includes a second physical property analysis execution means 161 that executes a second physical property analysis step S60 of the wet product taken out in the take-out 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. Note that, in this embodiment, a method is adopted in which a portion of the wet product taken out in the take-out step S35' is sampled and the physical properties are analyzed by the analysis device 151, but other analysis methods may be used.

[0108] [First storage process] The first storage step is a step of storing the wet catalyst cake taken out in the take-out step S35' in a container or bag. The container or bag used in this first storage step is made of plastic and has an antistatic agent applied to the inside. After the second physical property analysis step is performed, the wet product taken out in the take-out step S35' is stored in this plastic packaging container or packaging bag. This first storage step is performed in the atmosphere, and the wet product is stored in the packaging container or packaging bag while acclimatizing to the atmosphere. In this step, the take-out step S35' may be performed by placing a plastic packaging container or packaging bag below the opening 208 in advance and dropping the wet product from inside the container body 202 into the packaging container or packaging bag to directly store the wet product, or the take-out step S35' may be performed by first removing the wet product and then storing it in the plastic packaging container or packaging bag.

[0109] Thereafter, the plastic packaging container or packaging bag containing the wet catalyst cake is further placed in a container. The container used here is a stainless steel UN can (a container that displays a "UN inspection certificate (UN mark)" that has passed the container performance test conducted by the Japan Ship Equipment Inspection Association in accordance with international standards: a dangerous goods transport container), with an antistatic coating on the inside. This UN can is preferably made of SUS316, and is preferably capable of containing substances classified as UN number 3178, product name: other flammable substances, and UN classification: 4.1, with a packaging class of 2 or 3. After the second containing step is completed, this UN can is transferred and supplied to the customer.

[0110] [Second storage process] In another embodiment, the second storage step uses the UN can described above instead of the plastic packaging container or packaging bag used in the first storage step. In this case, the UN can used is configured to be able to hermetically store the wet product.

[0111] Example 2 [Reactor treatment (reslurry step)] The powder of electrode catalyst 1 obtained after the treatment with the drying device was introduced into a dropping funnel serving as a reactor 152, and a reslurry step S40 was carried out. The capacity of the dropping funnel was selected based on the liquid level in the reactor 152 when 100 g of electrode catalyst 1 powder and 400 ml of ion-exchanged water were introduced in the introduction step S41, and a dropping funnel with an effective capacity of 2 L and an agitation blade diameter of 8 cm was used as shown in Fig. 23. Note that the diameter of the liquid level when 100 g of electrode catalyst 1 powder and 400 ml of ion-exchanged water were introduced into this dropping funnel was 16 cm.

[0112] First, in the introduction step S41, 100 g of electrode catalyst 1 powder and 400 ml of ion-exchanged water were introduced into the dropping funnel. Immediately after the introduction, approximately 1 / 4 of the electrode catalyst 1 powder settled at the bottom of the dropping funnel, and the remaining electrode catalyst 1 powder was deposited on the liquid surface of the ion-exchanged water. When the mixture was left to stand for 30 minutes without driving the stirring device, most of the electrode catalyst 1 powder settled in the ion-exchanged water, while a portion of the electrode catalyst 1 powder was still deposited about 2 to 3 cm above the liquid surface of the ion-exchanged water. The deposited electrode catalyst 1 powder had absorbed the ion-exchanged water and was in a wet state.

[0113] From this state, the process moved to the mixing step S42, and the stirring device was driven so that the stirring blade rotated at 60 rpm (60 revolutions per minute), and the electrode catalyst 1 and the ion-exchanged water were stirred and mixed at room temperature and atmospheric pressure. Immediately after stirring, the electrode catalyst 1 and the ion-exchanged water were not immediately mixed. After 30 minutes had passed, the electrode catalyst 1 and the ion-exchanged water were mixed and stirred only in the center of the dropping funnel along the axis of the rotating stirring blade, while the electrode catalyst 1 and the outer periphery of the ion-exchanged water near the inner wall of the dropping funnel maintained the state of the electrode catalyst 1 powder as a wet powder, as before the transition to the mixing step S42. After 60 minutes had elapsed, the wetness of the wet powder on the outer periphery of the electrode catalyst 1 and the ion exchanged water, i.e., the area where the electrode catalyst 1 and the ion exchanged water are mixed and stirred, expanded, and the center and part of the outer periphery of the electrode catalyst 1 and the ion exchanged water began to turn into a slurry, while most of the outer periphery remained in the form of a wet cake of electrode catalyst 1 powder, just as before moving to the mixing process S42.

[0114] From this state, 100 ml of ion-exchanged water was further introduced, and the stirring device was driven so that the stirring blade of 100 g of electrode catalyst 1 powder and 500 ml of ion-exchanged water was rotated at 60 rpm, and the electrode catalyst 1 and the ion-exchanged water were stirred and mixed at room temperature and atmospheric pressure. After 30 minutes, the electrode catalyst 1 and the ion-exchanged water in the dropping funnel were entirely in a slurry state, while the viscosity was very high and the electrode catalyst 1 powder was scattered in a spherical shape. After 60 minutes, the electrode catalyst 1 powder that was scattered in a spherical shape had decreased, while the electrode catalyst 1 powder was scattered in a spherical shape around the edge of the electrode catalyst 1 and the ion-exchanged water near the inner wall of the dropping funnel, and the mixture had not yet become a complete slurry.

[0115] From this state, the rotation speed of the stirring blade was further increased, and the stirring device was driven so that the stirring blade was at 80 rpm with 100 g of electrode catalyst 1 powder and 500 ml of ion-exchanged water, and the electrode catalyst 1 and the ion-exchanged water were stirred and mixed at room temperature and atmospheric pressure. However, there was no dramatic change compared to when the stirring blade was at 60 rpm, and the electrode catalyst 1 powder was still scattered in a spherical shape around the edge of the electrode catalyst 1 and the ion-exchanged water, and no significant effect was found by increasing the rotation speed of the stirring blade. After that, the rotation speed of the stirring blade was further increased, and the stirring device was driven so that the stirring blade was at 250 rpm with 100 g of electrode catalyst 1 powder and 500 ml of ion-exchanged water, and the electrode catalyst 1 and the ion-exchanged water were stirred and mixed at room temperature and atmospheric pressure. As a result, the electrode catalyst 1 powder that was scattered in a spherical shape disappeared for the most part, including the edge of the electrode catalyst 1 and the ion-exchanged water, and changed into a completely slurry-like shape.

[0116] <Evaluation Results> When the ratio of electrode catalyst 1 powder to ion-exchanged water was 1:4 (powder:ion-exchanged water = 1:4), even when electrode catalyst 1 and ion-exchanged water were stirred and mixed, it was difficult to uniformly wet the entire mixture to form a slurry. Furthermore, when the ratio of the electrode catalyst 1 powder to the ion-exchanged water is 1:5 (powder:ion-exchanged water=1:5), it is difficult to make the electrode catalyst 1 and the ion-exchanged water into a slurry when the rotation speed of the stirring blade is 60 rpm, and even when the rotation speed of the stirring blade is 80 rpm, the electrode catalyst 1 and the ion-exchanged water cannot be completely made into a slurry. The rotation speed of the stirring blade is set to 80 rpm assuming the stirring blade 204 of the stirring treatment device 201, and therefore, it was found that it is difficult to execute the reslurry step S40 in the drying device 14 without using the reactor 152. When the ratio of electrode catalyst 1 powder to ion-exchanged water was 1:5 (powder:ion-exchanged water = 1:5), electrode catalyst 1 and ion-exchanged water could be completely slurried when the rotation speed of the stirring blade was 250 rpm, which exceeded 80 rpm.

[0117] Example 3 [Treatment using a drying device (drying step)] The cake containing the electrode catalyst precursor obtained after the treatment with the filter press as the washing device was introduced into the stirring device 201 as the drying device, and the drying step S3 was carried out. In the introduction step S31, the water content is 72.1 wt% and the apparent density is 540 kg / m 3 (Apparent density after tapping is 700kg / m 3 ) cake was introduced. Hereinafter, the moisture content (moisture content) of the cake or slurry is the weight of the moisture contained in the cake divided by the weight of the catalyst powder contained in the cake + the weight of the moisture, and the weight of the moisture was detected by heating the measurement container at a temperature of 70°C in air for 70 minutes, and measuring the weight change of the cake containing moisture in this measurement container before and after measurement with an infrared moisture meter. In the drying step S32, the vacuum pump 234 was driven to reduce the pressure inside the vessel body 202 to 12.3 kPa in gauge pressure, the stirring blade 204 was rotated at a rotation speed of 85 revolutions per minute, steam S was injected from the heating medium inlet 213 into the jacket 206 to set the heating temperature t1 of the vessel body 202 to 110°C, and the changes over time in the temperature t2 inside the vessel body 202, the temperature (actual measured product temperature) t3 of the electrode catalyst precursor, and the moisture content C1 of the cake were measured for 180 minutes. The graph and table of the measurement results are shown in Figure 24 (drying curve for Run 1). During this 180-minute drying step S32, the temperature inside the container body 202 rose from 18.8° C. to 77.8° C., and the temperature of the electrode catalyst precursor also rose from 19.7° C. to 108.9° C. Then, a cooling step S33 and a gradual oxidation step S34 were performed in this order, and in the removal step S35, the water content was 2.2 wt % and the apparent density was 450 kg / m 3 (Apparent density after tapping is 480kg / m 3 ) cake weighing 1.4 kg was extracted. The amount of electrode catalyst attached inside the container body 202 was 6.8 g, and the amount of electrode catalyst precursor taken out as a sample for measurement etc. was 46 g. The amount of condensate discharged through the bag filter 231 and condensed and collected in the condenser 233 was 3.1 kg.

[0118] Example 4 The reslurried electrode catalyst slurry obtained after the treatment in the kettle as the reactor 152 was introduced into the stirring treatment device 201 as the drying device, and the drying step S3 was carried out. In the introduction step S31, 11.25 kg of a slurry with a water content of 93.3 wt% was introduced. Here, the water content of the slurry was calculated by assuming that the water content of the electrode catalyst powder was 5 wt%, and calculating the weight of the ion-exchanged water introduced in the reslurry step S40. In the drying step S32, the vacuum pump 234 was driven to reduce the pressure inside the vessel body 202 to 12.3 kPa in gauge pressure, the stirring blade 204 was rotated at a rotation speed of 85 revolutions per minute, steam S was injected from the heating medium inlet 213 into the jacket 206 to set the heating temperature t4 of the vessel body 202 to 110°C, and the changes over time in the vessel body 202 internal tank temperature t5, the electrode catalyst precursor temperature (actual measured product temperature) t6, and the cake moisture content C2 were measured for 170 minutes. The graph and table of the measurement results are shown in Figure 25 (Run 2 drying curve). During this 170-minute drying step S32, the temperature t5 inside the container body 202 rose from about 20° C. to about 50° C., and the temperature t6 of the electrode catalyst precursor also rose from 20.2° C. to 52.5° C. Thereafter, the cooling step S33 and the gradual oxidation step S34 were carried out in this order, and in the removal step S35, the water content was 41.1 wt % and the apparent density was 840 kg / m 3 (Apparent density after tapping is 900kg / m 3 ) cake weighing 1.1 kg was extracted. The amount of electrode catalyst attached inside the vessel body 202 was 317 g, and the amount of electrode catalyst precursor taken out as a sample for measurement etc. was 45 g. The amount of condensate discharged through the bag filter 231 and condensed and collected in the condenser 233 was 9.3 kg.

[0119] <Evaluation Results> [Production of electrode catalysts] (1) A process in which an electrode catalyst precursor is produced in a kettle in an electrode catalyst precursor production step S1, filtered, washed and dehydrated using a filter press in a washing step S2 to obtain an electrode catalyst precursor with a moisture content of 60 to 80 wt%, and this electrode catalyst precursor is dried and roughly crushed in a stirring treatment device 201 in a drying step S3 to obtain an electrode catalyst with a moisture content of 1 to 5 wt%, and this electrode catalyst is crushed in a crusher to obtain an electrode catalyst powder. In this process, when the moistened catalyst cake, which is a cake of electrode catalyst precursor with a moisture content of 72.1 wt% obtained by filtering, washing and dehydrating using a filter press in the washing step S2, is introduced into the stirring treatment device 201, the moisture content of the moistened catalyst cake becomes 5.0 wt% in 145 minutes in the drying process S32 of the drying step S3 as shown in Figure 24, and the target electrode catalyst with a moisture content of 5.0 wt% in process (1) was produced in 145 minutes.

[0120] (2) A process in which an electrode catalyst precursor is produced in a kettle in an electrode catalyst precursor production step S1, filtered, washed and dehydrated in a centrifuge in a washing step S2 to obtain an electrode catalyst precursor with a moisture content of 60 to 80 wt%, and this electrode catalyst precursor is dried and roughly crushed in a stirring treatment device 201 in a drying step S3 to obtain an electrode catalyst with a moisture content of 1 to 5 wt%, and this electrode catalyst is crushed in a crusher to obtain an electrode catalyst powder. In this process as a comparative example, when a moistened catalyst cake, which is a cake of electrode catalyst precursor with a moisture content of 72.1 wt%, obtained by filtering, washing and dehydrating using a centrifuge in the washing step S2, is introduced into the stirring treatment device 201, in the drying step S32 of the drying step S3, the moisture content of the moistened catalyst cake becomes 5.0 wt% in 240 minutes, and the target electrode catalyst of 5.0 wt% in process (2) can be produced in 240 minutes.

[0121] [Production of wet catalyst cake from electrode catalyst powder] (3) In a reslurry step S40, the electrode catalyst powder obtained in step (1) is reslurried in a kettle as a reactor 152, and the slurry containing the electrode catalyst is dehydrated in a centrifuge to obtain an electrode catalyst having a moisture content of 60 to 80 wt %. In this process, a slurry having a moisture content of 93.3 wt% for use in Example 4 was prepared using a kettle, and this slurry was dehydrated using a centrifuge to prepare a moistened catalyst cake having a moisture content of 72.1 wt%.

[0122] (4) In a catalyst cake preparation step S50, the electrode catalyst having a moisture content of 60 to 80 wt% obtained in the process (3) is dried and coarsely crushed by a stirring treatment device 201 to obtain an electrode catalyst having a moisture content of 20 to 75 wt%, preferably an electrode catalyst having a moisture content of 30 to 70 wt%. In this process, when the moistened catalyst cake with a moisture content of 72.1 wt% is introduced into the stirring device 201, the moisture content of the moistened catalyst cake decreases further to 20.3-69.8 wt% in 5-120 minutes in drying step S32 of drying step S3 as shown in Fig. 24, and an electrode catalyst with a moisture content of 20-75 wt%, which is the target for step (4), can be produced in 5-120 minutes. Also, the moisture content of the moistened catalyst cake increases to 31.3-69.8 wt% in 5-95 minutes, and an electrode catalyst with a moisture content of 30-70 wt%, which is the preferred target for step (4), can be produced in 5-95 minutes.

[0123] (5) In a reslurry step S40, the electrode catalyst powder obtained in step (1) is reslurried in a kettle as a reactor 152, and the slurry containing the electrode catalyst is dehydrated using a filter press to obtain an electrode catalyst having a moisture content of 60 to 80 wt %. In a drying step S3, this electrode catalyst is dried and roughly pulverized using a stirring treatment device 201 to obtain an electrode catalyst having a moisture content of 20 to 75 wt %, preferably an electrode catalyst having a moisture content of 30 to 70 wt %. Comparing (1) and (2), it can be understood from the above-mentioned first embodiment that dehydration can be performed using a filter press instead of a centrifuge, and in this case, the dehydration time can be shortened. Therefore, it is assumed that the same results as in the process of (4) can be obtained by dehydrating using a filter press to prepare a moistened catalyst cake with a moisture content of 72.1 wt%, and then drying and coarse pulverization are performed using the stirring device 201.

[0124] (6) In a reslurry step S40, the electrode catalyst powder obtained in the process (1) is reslurried in a kettle as a reactor 152, and the slurry containing the electrode catalyst is directly introduced into the agitation processing device 201, where it is dried and coarsely pulverized to obtain an electrode catalyst having a moisture content of 20 to 75 wt%, preferably an electrode catalyst having a moisture content of 30 to 70 wt%. In this process, when the slurry reslurried in the kettle with a moisture content of 93.3 wt% is introduced into the stirring treatment device 201, as shown in Figure 25, in the drying step S32' of the catalyst cake preparation step S50, the moisture content of the moistened catalyst cake decreases further to 41.1 to 74.7 wt% in 87 to 170 minutes, and although it takes a little longer than step (4), in step (6) an electrode catalyst with the target moisture content of 30 to 70 wt% can be produced in 87 to 170 minutes.

[0125] (Reference example) (7) A process of introducing the electrode catalyst powder obtained in step (1) and ion-exchanged water into the agitation treatment device 201 to form a reslurry, and drying and coarsely pulverizing the slurry containing the electrode catalyst in the agitation treatment device 201 using the agitation treatment device 201 to obtain an electrode catalyst having a water content of 20 to 75 wt%, preferably an electrode catalyst having a water content of 30 to 70 wt%. In this step, it was not possible to reslurry the electrode catalyst powder and ion-exchanged water using the agitation treatment device 201 as described above.

[0126] Although the present invention has been described above based on the embodiment and examples, the present invention can be embodied in various modified forms. In particular, the electrode catalyst precursor manufacturing apparatus 12 (reaction step, electrode catalyst precursor manufacturing apparatus step S1) and the cleaning apparatus 13 (cleaning step S2) are not particularly limited, and various modified forms can be adopted.

[0127] For example, the structure of the cleaning device 13 is not limited to that shown in Fig. 2, and the structure of the filter chamber 112 is not limited to that shown in Fig. 3 to Fig. 10, and various modified examples can be adopted as long as the structure provides similar effects in each of steps S21 to S27 of the cleaning step S2 and the squeezing step according to this embodiment. Similarly, the structure of the drying device 14 is not limited to that shown in Fig. 11, and the structure of the container body 202 is not limited to that shown in Fig. 11 to Fig. 13, and various modified examples can be adopted as long as the structure provides similar effects in each of steps S31 to S35 of the drying step S3 according to this embodiment. [Explanation of symbols]

[0128] 1 Electrode catalyst 2. Carrier 3. Catalyst particles 4 Core 5 Shell 10. Electrode catalyst manufacturing system 12 Electrode catalyst precursor production equipment 13 Cleaning equipment 14 Drying equipment 201 Mixing treatment device 202 Container body 204 Stirring blade 222 Rotating shaft 223 Spiral Ribbon Rotor 224 Arm (rotor support) 226 Gas Vent 152 Reactor S1 Electrode catalyst precursor manufacturing step S2 Wash step S3 Drying step S31 Introduction process S32 Drying process S33 Cooling process S34 Gradual oxidation process S35 Removal process S36 First physical property analysis step (first analysis process) S40 Resrally Step S50 Catalyst cake preparation step S60 Second physical property analysis step (second analysis process) [Industrial Applicability]

[0129] According to the electrode catalyst manufacturing system and manufacturing method of the present invention, the labor and time required to manufacture an electrode catalyst having a low halogen content, particularly a low chlorine content, can be significantly reduced by eliminating the need for an operator to transfer the electrode catalyst precursor and shortening the drying time of the electrode catalyst precursor.

[0130] Therefore, the present invention is a manufacturing system and method for electrode catalysts that can be applied not only to the electrical equipment industry, such as fuel cells, fuel cell vehicles, and portable mobile devices, but also to ENE-FARMs and cogeneration systems, and will contribute to the development of the energy industry and environmental technologies.

Claims

1. an electrode catalyst precursor manufacturing apparatus for manufacturing an electrode catalyst precursor, which is a raw material for an electrode catalyst; A cleaning device for cleaning the electrode catalyst precursor; a drying device that dries the electrode catalyst precursor washed by the washing device using an agitation treatment device equipped with an agitation blade having a spiral ribbon rotor, The drying device is an introduction step of introducing the electrode catalyst precursor into a vessel body of the stirring treatment device; a drying step of heating the container body while reducing the pressure, and stirring and mixing the electrode catalyst precursor in the container body with the stirring blade, thereby drying the electrode catalyst precursor; a cooling step of cooling the electrode catalyst precursor by cooling and reducing the pressure of the container body and stirring and mixing the electrode catalyst precursor in the container body with the stirring blade; a gradual oxidation step of supplying air into the container body and subjecting the electrode catalyst precursor to a gradual oxidation treatment; and removing the electrode catalyst precursor from the container body.

2. the stirring blade includes a main shaft that is rotated by a drive device to rotate the stirring blade, the spiral ribbon rotor that stirs and mixes the electrode catalyst precursor in the container body, and a rotor support that connects the main shaft and the spiral ribbon rotor, The rotor shaft and the rotor support are formed in a hollow tubular shape, The rotor support has a gas outlet hole on the lower side of the tip, 2. The system for manufacturing an electrode catalyst according to claim 1, wherein the rotating shaft is connected to a gas flow path.

3. an electrode catalyst precursor producing step of producing an electrode catalyst precursor which is a raw material for the electrode catalyst; a washing step of washing the electrode catalyst precursor; a drying step of drying the electrode catalyst precursor after the washing step by using an agitation treatment device equipped with an agitation blade having a spiral ribbon rotor, The drying step comprises: a drying step of drying the electrode catalyst precursor by heating and reducing the pressure of a container body of the stirring treatment device and stirring and mixing the electrode catalyst precursor in the container body with the stirring blade; a cooling step of cooling the electrode catalyst precursor by cooling and reducing the pressure of the container body and stirring and mixing the electrode catalyst precursor in the container body with the stirring blade; and a gradual oxidation step of supplying air into the container body and subjecting the electrode catalyst precursor to a gradual oxidation treatment.

4. The method further includes a removal step of removing the electrode catalyst precursor from the container body, 4. The method for producing an electrode catalyst according to claim 3, wherein the removing step includes a scraper step of ejecting gas downward from gas ejection holes provided at the tip of a rotor support supporting the spiral ribbon rotor.

5. a first analysis step of performing a physical property analysis of the electrode catalyst precursor obtained through the drying step; a reslurry step of mixing the electrode catalyst precursor obtained through the drying step with ion-exchanged water to prepare a slurry again; A catalyst cake preparation step of drying the slurry obtained through the reslurry step to prepare a plurality of solid catalyst cakes having a moisture content adjusted to a predetermined range; The method for producing an electrode catalyst according to claim 3 , further comprising:

6. The method for producing an electrode catalyst according to claim 5 , wherein the stirring treatment device is an agitation type drying device used in the catalyst cake preparation step.

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

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

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

10. The method for producing an electrode catalyst according to any one of claims 5 to 9, further comprising a second analysis step of measuring a water content of the catalyst cake obtained through the catalyst cake preparation step.

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