Supported catalyst synthesis equipment

Abstract

To provide an apparatus for synthesizing a carried catalyst capable of having a single metal fine particle or a solid solution fine particle so small diameter as 0.5-2 nm, and stably mass-producing a carried catalyst in a carried catalyst carried with the single metal fine particle or the solid solution fine particle on a carrier particle.SOLUTION: An apparatus for synthesizing a carried catalyst at least includes: a first supply source of a liquid containing a reductant; a fourth supply source for storing a mixture of a liquid containing an element constituting a single metal fine particle or a solid solution fine particle carried, and a liquid containing a carrier particle; a reaction part (D) for merging the liquid containing the reductant with the mixture; a liquid-sending route (A) for connecting the first supply source with the reaction part (D); a common route (B, C) for connecting the fourth supply source with the reaction part (D); and a recovery part (E) for recovering a generated reaction product by connecting to the reaction part (D) through piping. The apparatus further includes a pressure adjust mechanism (F) connected to the recovery part (E).SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a supported catalyst synthesis apparatus capable of continuously synthesizing a supported catalyst (hereinafter also referred to as a supported catalyst) in which fine metal particles or solid solution particles are supported on carrier particles, and a microparticle synthesis apparatus capable of continuously synthesizing fine metal particles or solid solution particles. [Background technology]

[0002] In general, catalysts containing rare metals are widely used in catalysts used for purifying exhaust gas from automobiles, etc., and various reaction processes such as chemical compound synthesis. However, because rare metals are expensive and produced in small quantities, solid solution microparticles, which are said to be highly active while using less rare metal, have attracted attention, and their development is underway.

[0003] To synthesize such solid solution particles, a batch synthesis method is used in which a high-boiling reducing agent such as triethylene glycol is heated to a high temperature and a precious metal salt solution is gradually added. However, as the concentration of the precious metal in the reducing agent solution to be synthesized gradually increases, problems arise, such as the coarsening of particle size, making it difficult to mass-produce alloys with small particle sizes.

[0004] In recent years, there has been a demand for catalysts with higher activity while reducing the amount of precious metal, and industrial demand has also arisen for the mass production of supported catalysts in which solid solution particles of 1 nm or less are supported on support particles. As a means for preventing the coarsening of such solid solution particles, there is a method for synthesizing solid solution particles using a microreactor (see, for example, Patent Document 1). Palladium and ruthenium solid solution particles are produced by reacting a palladium metal salt solution and a ruthenium metal salt solution under pressure in a microreactor in the presence of a reducing agent. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-141235 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology described in Patent Document 1 requires an average particle size of at least 2.2 nm, and for the particles to be active when used as a catalyst, it is necessary to reduce the particle size to 0.5 to 2 nm, preferably 1 nm or less, so as to increase the surface area. Furthermore, no examples of the synthesis of supported catalysts are given, and no structure is shown that allows the support particles necessary for the synthesis of supported catalysts to be stably introduced into the system.

[0007] Although Patent Document 1 achieved the success of mass synthesis of solid solution microparticles, the particle size of the solid solution microparticles needs to be further reduced. That is, there is a problem that the reducing power required to reduce the particle size is insufficient, and the reaction must be carried out under conditions of even higher reducing power. Furthermore, there is a problem that even smaller particle sizes must be achieved in mass production equipment.

[0008] Furthermore, in Patent Document 1, the synthesis of the supported catalyst is not performed within the apparatus. Furthermore, in terms of stably mass-producing a supported catalyst while introducing support particles, Patent Document 1 has a fatal flaw in that it does not take into consideration the flow of support particles in the back-pressure valve. Specifically, when solid support particles are introduced into the apparatus, the support particles become stuck or clog the back-pressure valve, preventing the synthesis reaction from proceeding at the desired flow rate, pressure, and temperature. Furthermore, there is the issue of needing to resolve the problem of support particle sticking and clogging in the mass-production apparatus.

[0009] Therefore, an object of the present disclosure is to provide a supported catalyst synthesis apparatus that can achieve small particle diameters of the single metal particles or solid solution particles to approximately 0.5 to 2 nm in supported catalysts in which single metal particles or solid solution particles are supported on carrier particles, and that can stably mass-produce supported catalysts. [Means for solving the problem]

[0010] As a result of extensive research conducted by the inventors to solve the above-mentioned problems, they discovered that the above-mentioned problems can be solved by combining (1) a liquid containing a reducing agent and a liquid containing elements that constitute single metal microparticles or solid solution microparticles, or (2) a liquid containing a reducing agent, a liquid containing elements that constitute the single metal microparticles or solid solution microparticles to be supported, and a liquid containing carrier particles, and then reacting them, and then providing a mechanism for controlling pressure at the point where the resulting reaction product is recovered, thereby completing the present invention. That is, the supported catalyst synthesis apparatus of the present invention is characterized by having at least a first supply source of a liquid containing a reducing agent, a fourth supply source for storing a mixed liquid of a liquid containing elements that constitute the single metal microparticles or solid solution microparticles to be supported and a liquid containing support particles, a reaction section (D) for merging the liquid containing the reducing agent and the mixed liquid, a liquid delivery route (A) connecting the first supply source and the reaction section (D), shared routes (B, C) connecting the fourth supply source and the reaction section (D), and a recovery section (E) connected to the reaction section (D) via piping and for recovering the produced reactant, and further having a pressure adjustment mechanism (F) connected to the recovery section (E).

[0011] The supported catalyst synthesis apparatus of the present invention preferably includes a mechanism (G) for unidirectionally transporting the liquid flowing in either the liquid delivery route (A) or the shared routes (B, C), or both. Since the flow rate and flow velocity of the liquid containing the reducing agent can be stably controlled in the liquid delivery route (A), the supported catalyst can be stably synthesized. Furthermore, since the flow rates and flow velocities of the liquid containing the elements constituting the monometallic microparticles or solid solution microparticles to be supported and the liquid containing the carrier particles can be stably controlled in the shared routes (B, C), the supported catalyst can be stably synthesized.

[0012] In the supported catalyst synthesis apparatus according to the present invention, the shared route (B, C) preferably has a stirring mechanism (H), which can prevent support particles, which have a specific gravity heavier than water, from settling in the pump and maintain a constant concentration of support particles sent to the reaction section.

[0013] In the supported catalyst synthesis apparatus according to the present invention, it is preferable that a heating and heat-retaining mechanism (I) is provided in the liquid transport route (A). By heating the liquid containing the reducing agent from room temperature to a temperature required for the reaction, the amount of heat required for the reduction can be provided.

[0014] In the supported catalyst synthesis apparatus according to the present invention, it is preferable to have a cooling mechanism (J2) between the reaction section (D) and the recovery section (E). By rapidly cooling the liquid containing the supported catalyst produced in the reaction section (D), sintering between single metal particles or between solid solution particles can be suppressed.

[0015] In the supported catalyst synthesis apparatus according to the present invention, it is preferable that the shared route (B, C) has a cooling mechanism (J1), which can prevent unexpected deposition of metals due to the influence of heat transfer. [Effects of the Invention]

[0016] According to the present disclosure, it is possible to provide a supported catalyst synthesis apparatus that can realize small particle diameters of the single metal particles or solid solution particles to about 0.5 to 2 nm in a supported catalyst in which the single metal particles or solid solution particles are supported on a carrier particle, and that can stably mass-produce supported catalysts. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic diagram of a first example of a supported catalyst synthesis apparatus according to the present embodiment. [Figure 2] FIG. 2 is a schematic diagram of a second example of an apparatus for synthesizing a supported catalyst according to the present embodiment. [Figure 3] FIG. 2 is a schematic diagram of a third example of an apparatus for synthesizing a supported catalyst according to the present embodiment. [Figure 4(A)] FIG. 10 is a schematic diagram showing an example of a mechanism (G) for transferring a liquid in one direction, and is a schematic diagram showing when the plunger is pressed down. [Figure 4(B)] FIG. 10 is a schematic diagram showing an example of a mechanism (G) for transferring a liquid in one direction, showing a state in which the plunger is pushed up. [Figure 5]FIG. 10 is a schematic diagram showing an example in which a mechanism (G) for transferring a liquid in one direction further includes a stirring mechanism (H). [Figure 6] FIG. 1 is a schematic diagram of a fourth example of an apparatus for synthesizing a supported catalyst, which is obtained by further providing a heating and holding mechanism (I) and a cooling mechanism (J1, J2) in addition to the second example of the apparatus for synthesizing a supported catalyst according to the present embodiment. [Figure 7] 1 is a schematic diagram of a first example of a fine particle synthesis apparatus according to an embodiment of the present invention. [Figure 8] FIG. 2 is a schematic diagram of a second example of the fine particle synthesis apparatus according to the present embodiment. [Figure 9] FIG. 10 is a schematic diagram of a third example of a microparticle synthesis apparatus in which a heating and holding mechanism (I) and a cooling mechanism (J1, J2) are further provided in addition to the second example of the microparticle synthesis apparatus according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, the present invention will be described in detail with reference to the embodiments, but the present invention is not limited to these descriptions. Various modifications may be made to the embodiments as long as the effects of the present invention are achieved.

[0019] (Supported catalyst synthesis equipment) A supported catalyst synthesis apparatus will be described with reference to Figure 1. The supported catalyst synthesis apparatus 100 according to this embodiment includes at least a first supply source 3 for a liquid containing a reducing agent, a second supply source 1 for a liquid containing elements constituting the monometallic fine particles or solid solution fine particles to be supported, a third supply source 2 for a liquid containing support particles, a reaction section (D) where the liquid containing the reducing agent, the liquid containing elements constituting the monometallic fine particles or solid solution fine particles to be supported, and the liquid containing support particles are joined, a liquid delivery route (A) connecting the first supply source 3 and the reaction section (D), a liquid delivery route (B) connecting the second supply source 1 and the reaction section (D), a liquid delivery route (C) connecting the third supply source 2 and the reaction section (D), and a recovery section (E) connected to the reaction section (D) via piping and for recovering the generated reactant, and further includes a pressure adjustment mechanism (F) connected to the recovery section (E). According to the supported catalyst synthesis apparatus of this embodiment, it is possible to control the pressure inside the apparatus without using a back pressure valve, which makes it difficult for the slurry to clog the apparatus, which was previously an issue, and allows for stable synthesis of supported catalysts.

[0020] In the supported catalyst synthesis apparatus according to this embodiment, a liquid containing elements constituting the monometallic particles or solid solution particles to be supported is reduced in the reaction section (D) to form monometallic particles or solid solution particles, and the monometallic particles or solid solution particles produced by the reduction can be supported on carrier particles.

[0021] The first supply source 3 of the liquid containing the reducing agent is preferably a container for storing a liquid containing the reducing agent. As the reducing agent, a reducing organic solvent such as methanol, ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol, triethylene glycol, trimethylene glycol, or diethylene glycol is used. These may be diluted with a solvent such as water, and further, an alkali, an organic acid, or the like may be added to the solvent such as water to adjust the reducing property.

[0022] The second supply source 1 of the liquid containing the elements constituting the monometallic particles or solid solution particles to be supported is preferably a container for storing the liquid containing the elements constituting the monometallic particles or solid solution particles to be supported. Examples of elements constituting the monometallic particles or solid solution particles include palladium, ruthenium, rhodium, silver, osmium, iridium, platinum, gold, molybdenum, rhenium, tungsten, 3d transition elements, carbon, and boron. To produce monometallic particles, a raw material containing one of these metal elements is used. This raw material is prepared into a raw material solution with a liquid such as water. To produce solid solution particles, a raw material containing two or more of these metal elements is used. These metal raw materials are prepared into a raw material solution with a liquid such as water. Combinations of two or more metal elements include combinations that form a solid solution in an alloy phase diagram, combinations that do not form a solid solution, and combinations that form an intermetallic compound.

[0023] The third supply source 2 for the liquid containing support particles is preferably a container for storing the liquid containing support particles. Examples of types of support particles include silica, alumina, ceria, zirconia, ceria-zirconia, titania, magnesia, tin oxide, activated carbon, carbon black, acetylene black, carbon nanotubes, carbon nanofibers, and carbon nanohorns. The liquid containing support particles is a liquid in which support particles are dispersed in a dispersion medium, such as water. As the dispersion medium, a reducing organic solvent such as methanol, ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol, triethylene glycol, trimethylene glycol, or diethylene glycol may be used. Alkalis, organic acids, or the like may be added to the dispersion medium to adjust the reducing properties.

[0024] The liquid transfer route (A) connecting the first supply source 3 and the reaction section (D) includes a pipe. One method for adjusting the flow rate of the liquid flowing through the pipe is to place the first supply source 3 at a higher position than the reaction section (D) and utilize the difference in elevation. In this case, the liquid containing the reducing agent can be transported using only the pipe. In this case, a valve for throttling the flow rate, such as a needle valve or a stop valve, may be placed in the liquid transfer route (A).

[0025] The liquid transfer route (B) connecting the second supply source 1 and the reaction section (D) includes a pipe. One method for adjusting the flow rate of the liquid flowing through the pipe is to place the second supply source 1 at a higher position than the reaction section (D) and utilize the difference in elevation. In this case, a valve for throttling the flow rate, such as a needle valve or a stop valve, may be placed in the liquid transfer route (B) as in the liquid transfer route (A).

[0026] The liquid transfer route (C) connecting the third supply source 2 and the reaction section (D) includes a pipe. One method for adjusting the flow rate of the liquid flowing through the pipe is to place the third supply source 2 at a higher position than the reaction section (D) and utilize the difference in elevation. In this case, a valve for throttling the flow rate, such as a needle valve or a stop valve, may be placed in the liquid transfer route (C) as in the liquid transfer route (A).

[0027] The liquid sending route (B) and the liquid sending route (C) may be connected separately to the reaction section (D). As shown in Figure 1, the liquid sending route (B) and the liquid sending route (C) may be joined before reaching the reaction section (D), and the joined common route (B, C) may be connected to the reaction section (D).

[0028] The supported catalyst synthesis apparatus according to this embodiment preferably includes a mechanism (G) for unidirectionally transporting the liquid flowing in either the liquid feed route (B) or the liquid feed route (C), or both. The supported catalyst synthesis apparatus 200 shown in FIG. 2 has a configuration in which the mechanism (G) is provided in both the liquid feed route (B) and the liquid feed route (C). This configuration allows for stable regulation of the flow rates and flow velocities of the liquid containing the elements constituting the monometallic fine particles or solid solution fine particles to be supported and the liquid containing the carrier particles in the liquid feed route (B) and the liquid feed route (C), thereby enabling stable synthesis of the supported catalyst.

[0029] 2, the supported catalyst synthesis apparatus 200 according to this embodiment may further include a mechanism (G) for unidirectionally transferring the liquid flowing in the liquid transfer route (A). In this configuration, the flow rate and flow velocity of the liquid containing the reducing agent in the liquid transfer route (A) can be stably determined, thereby enabling stable synthesis of the supported catalyst.

[0030] The mechanism (G) is a means for adjusting the flow rate of the liquid flowing through the pipe, and is, for example, a plunger, a cylinder, or a regulator.

[0031] As shown in Figure 3, the supported catalyst synthesis apparatus 300 of this embodiment may have, instead of the second supply source 1 and liquid delivery route (B) and the third supply source 2 and liquid delivery route (C) as shown in Figure 2, a fourth supply source 4 that stores a mixed liquid of a liquid containing elements that constitute the single metal microparticles or solid solution microparticles to be supported and a liquid containing carrier particles, and a shared route (B, C) for the liquid delivery route (B) and the liquid delivery route (C).

[0032] Next, let us refer to Figures 4(A) and 4(B). Figures 4(A) and 4(B) are schematic diagrams showing an example of a mechanism (G) for transferring liquid in one direction. Figure 4(A) is a schematic diagram when the plunger is pushed down, and Figure 4(B) is a schematic diagram when the plunger is pushed up. As shown in Figure 4(A), when the plunger 12 is pushed down, the discharge-side ball 10b closes the discharge-side pipe 11b, and the suction-side ball 10a opens the suction-side pipe 11a. As a result, the volume of the space 13 increases and the amount of stored liquid increases. Next, as shown in Figure 4(B), when the plunger 12 is pushed up, the discharge-side ball 10b opens the discharge-side pipe 11b and the suction-side ball 10a closes the suction-side pipe 11a. As a result, the volume of the space 13 decreases and the amount of stored liquid decreases, and the reduced amount of stored liquid becomes the amount of liquid discharged from the discharge side. In the liquid transfer route (B), the liquid transfer route (C), and the liquid transfer route (A), the liquid transfer amount is adjusted by the mechanism (G), backflow is suppressed, and the liquid can be continuously transferred to the reaction section (D) at a constant flow rate without pulsation. The plunger may be a single-plunger type or a double-plunger type, and a roller pump type or a syringe pump type may also be used. In Figures 4(A) and 4(B), a solenoid valve or a ball valve may be used instead of the check valve using the suction-side ball 10a and the discharge-side ball 10b. Also, a diaphragm may be used instead of the plunger.

[0033] In the supported catalyst synthesis apparatus according to this embodiment, the liquid transfer route (C) preferably includes an agitation mechanism (H). A mechanism (G) is provided when transferring support particles from the liquid transfer route (C) to the reaction section (D). However, the support particles may sink below the mechanism (G). Therefore, by providing an agitation mechanism (H) in the mechanism (G), the support particles can be prevented from sinking below the mechanism (G), enabling the support particles to be uniformly transferred to the reaction section (D). Figure 5 is a schematic diagram showing an example in which the mechanism (G) that transfers the liquid in one direction further includes an agitation mechanism (H). The agitation mechanism (H) is the agitation blade 14 shown in Figure 5. Other examples of the agitation mechanism (H) include a liquid circulation device and a stirrer.

[0034] The reaction section (D) is a reaction vessel in which a liquid containing a reducing agent, a liquid containing elements constituting the monometallic fine particles or solid solution fine particles to be supported, and a liquid containing support particles are joined together. The reaction conditions can be controlled by selecting and adjusting the shape, volume, and liquid flow pattern of the reaction vessel. Reaction vessels also include vessels in the form of pipes. The reaction section (D) is preferably a pressure vessel so that the reaction can proceed under pressure. Furthermore, the reaction section (D) may be equipped with a heating means for heating the liquid placed therein, such as a resistance heating element, a far-infrared irradiation device, a microwave irradiation device, direct current heating, dielectric heating, induction heating, an electric furnace, or a heater.

[0035] The recovery section (E) is a vessel connected to the reaction section (D) via a pipe for recovering the reaction product. The recovery section (E) is preferably a pressure vessel so that the reaction in the reaction section (D) can proceed under pressure.

[0036] The pressure adjustment mechanism (F) is connected to the recovery section (E). The pressure adjustment mechanism (F) may be connected to the recovery section (E) via piping. Alternatively, the pressure adjustment mechanism (F) may be connected to the recovery section (E) in an integrated state. The pressure adjustment mechanism (F) may be a pressurization / depressurization means such as a plunger, cylinder, or regulator. However, a cylinder is preferred because it is less susceptible to wear and clogging. The pressure adjustment mechanism (F) adjusts the pressure inside the recovery section (E) and the pressure inside the reaction section (D), which is connected to the recovery section (E) via piping. Since the liquid delivery route (A), liquid delivery route (B), and liquid delivery route (C), which are upstream of the reaction section (D), are also connected to the reaction section (D), the internal space of the route is pressurized. However, the liquid is delivered to the reaction section (D) at a pressure higher than this pressure. When a liquid containing a carrier carrying single metal particles or solid solution particles is recovered in the recovery section (E), the pressure in the reaction section (D) is adjusted by adjusting the pressure in the recovery section (E) with the pressure adjustment mechanism (F), thereby promoting the reduction of the elements that make up the single metal particles or solid solution particles in the reaction section (D). To achieve conditions that promote reduction, it is preferable to apply high energy, and the pressure in the recovery section (E) can be adjusted with the pressure adjustment mechanism (F) so that the reducing agent in the reaction section (D) is heated to a high temperature without boiling.

[0037] As shown in FIG. 6, the supported catalyst synthesis apparatus 400 according to this embodiment preferably has a heating and heat-retaining mechanism (I) in the liquid transfer route (A). By heating the liquid containing the reducing agent from room temperature to the temperature required for the reaction, the amount of heat required for reduction can be provided, improving the reactivity of the reducing agent. Examples of the heating and maintaining mechanism (I) include direct resistance heating, dielectric heating, induction heating, an electric furnace, and heating using a heater. However, direct resistance heating, dielectric heating, or induction heating is more preferred, as they are considered to have high temperature control responsiveness and avoid unexpected reduction of metal salts due to heat transfer to piping.

[0038] As shown in FIG. 6, the supported catalyst synthesis apparatus 400 according to this embodiment preferably has a cooling mechanism (J2) between the reaction section (D) and the recovery section (E). Rapid cooling of the liquid containing the supported catalyst produced in the reaction section (D) can suppress sintering of the metal particles or sintering of the solid solution particles. To further suppress sintering of the particles, the cooling mechanism (J2) is preferably located as close as possible to the reaction section (D), and more preferably, the end of the cooling mechanism (J2) closest to the reaction section (D) is located 1 to 1000 mm away from the reaction section (D). The cooling mechanism (J2) is located between the reaction section (D) and the recovery section (E), but a cooling mechanism (J1) may be provided in addition to the cooling mechanism (J2). A liquid containing the elements constituting the nanoparticles to be supported and a liquid containing carrier particles are introduced into the reaction section (D) via the liquid delivery route (B) and the liquid delivery route (C), and a cooling mechanism (J1) may be provided immediately before the introduction into the reaction section (D). To prevent unexpected metal precipitation due to the influence of heat transfer, a cooling mechanism (J1) may be provided in the liquid delivery route (B) and / or the liquid delivery route (C) as necessary. Examples of cooling means include water cooling and air cooling.

[0039] In an example of preparing a supported catalyst using the supported catalyst synthesis apparatus according to this embodiment, a liquid containing an ethanol-containing aqueous solution as a reducing agent is introduced into the first supply source 3. The reducing agent is then heated to room temperature to 450°C using a heater via the heating and insulation mechanism (I) along the liquid transport route (A) for transporting the reducing agent, and then transported to the reaction section (D). A Pd raw material solution and a Ru raw material solution are introduced into the second supply source 1 as liquids containing the single metal elements to be supported, and then transported to the reaction section (D) via the liquid transport route (B). A liquid containing alumina as a carrier to be supported is introduced into the third supply source 2, and then transported to the reaction section (D) while operating the mechanism (G) for transporting the flowing liquid in one direction and the stirring mechanism (H). The ethanol-containing aqueous solution, Pd raw material solution, Ru raw material solution, and alumina join in the reaction section (D), and the Pd and Ru raw materials are simultaneously reduced on the alumina by the ethanol-containing aqueous solution. The Pd and Ru elements are combined to form solid solution particles, which are then supported on the alumina, forming a supported catalyst. The formed supported catalyst is rapidly cooled to room temperature using water cooling in the cooling mechanism (J2). Rapid cooling prevents sintering of particles. The rapidly cooled supported catalyst is recovered in the recovery section (E) connected to the pressure adjustment mechanism (F), and boiling of the reducing agent is suppressed by controlling the pressure to 0.1 MPa to 138 MPa. By increasing the pressure, the pressure of the entire device is increased, and the activity of the reaction in the reaction section (D) is improved.

[0040] (Fine particle synthesis device) Next, the microparticle synthesis apparatus will be explained, but since it includes the same content as the supported catalyst synthesis apparatus, the explanation will focus on the differences.

[0041] First, a microparticle synthesis apparatus will be described with reference to FIG. 7. The microparticle synthesis apparatus 500 according to this embodiment includes at least a first supply source 3 of a liquid containing a reducing agent, a second supply source 1 of a liquid containing elements constituting monometallic or solid-solution microparticles, a reaction section (D) where the liquid containing the reducing agent and the liquid containing elements constituting the monometallic or solid-solution microparticles are joined, a liquid transfer route (A) connecting the first supply source 3 to the reaction section (D), a liquid transfer route (B) connecting the second supply source 1 to the reaction section (D), and a recovery section (E) connected to the reaction section (D) via a pipe for recovering the generated reactant. The apparatus further includes a pressure adjustment mechanism (F) connected to the recovery section (E). The microparticle synthesis apparatus according to this embodiment enables pressure control within the apparatus without using a backpressure valve, which reduces the clogging problem of monometallic or solid-solution microparticles within the apparatus and enables stable synthesis of monometallic or solid-solution microparticles.

[0042] In the microparticle synthesis apparatus according to this embodiment, the reaction section (D) can reduce a liquid containing elements that constitute simple metal microparticles or solid solution microparticles to form simple metal microparticles or solid solution microparticles.

[0043] The first supply source 3, type of reducing agent, second supply source 1, liquid delivery route (A), liquid delivery route (B), reaction section (D), recovery section (E), and pressure adjustment mechanism (F) are the same as those in the supported catalyst synthesis apparatus of this embodiment. Furthermore, the type of liquid containing the elements that constitute the single metal fine particles or solid solution fine particles is the same as the "type of liquid containing the elements that constitute the single metal fine particles or solid solution fine particles to be supported" in the supported catalyst synthesis apparatus of this embodiment.

[0044] The microparticle synthesis apparatus according to this embodiment preferably has a mechanism (G) for unidirectionally transporting the liquid flowing through the liquid delivery route (B). Since the flow rate and flow velocity of the liquid containing the elements constituting the single metal microparticles or solid solution microparticles can be stably regulated in the liquid delivery route (B), stable microparticle synthesis can be achieved. The microparticle synthesis apparatus 600 shown in FIG. 8 has a configuration in which mechanisms (G) are provided in both the liquid delivery route (B) and the liquid delivery route (A). In this configuration, the flow rates and flow velocity of the liquid containing the elements constituting the single metal microparticles or solid solution microparticles and the liquid containing the reducing agent can be stably regulated in the liquid delivery route (B) and the liquid delivery route (A), stable microparticle synthesis can be achieved.

[0045] The specific structure of the mechanism (G) is the same as that of the supported catalyst synthesis apparatus according to this embodiment.

[0046] In the microparticle synthesis apparatus according to this embodiment, it is preferable to have a heating and heat-retaining mechanism (I) in the liquid transfer route (A), as shown in Figure 9. By heating the liquid containing the reducing agent from room temperature to the temperature required for the reaction, the amount of heat required for reduction can be provided. The specific structure of the heating and heat-retaining mechanism (I) is the same as in the supported catalyst synthesis apparatus according to this embodiment.

[0047] In the microparticle synthesis apparatus according to this embodiment, as shown in FIG. 9, it is preferable to have a cooling mechanism (J2) between the reaction section (D) and the recovery section (E). By rapidly cooling the liquid containing the single metal microparticles or solid solution microparticles generated in the reaction section (D), sintering between particles can be suppressed. The specific structure of the cooling mechanism (J2) is the same as that of the supported catalyst synthesis apparatus according to this embodiment. In addition to the cooling mechanism (J2), a cooling mechanism (J1) may be provided. While the liquid containing the elements that constitute the nanoparticles is introduced to the reaction section (D) via the liquid delivery route (B), a cooling mechanism (J1) may be provided immediately before the liquid is introduced to the reaction section (D). To prevent unexpected metal precipitation due to the effects of heat transfer, a cooling mechanism (J1) may be provided in the liquid delivery route (B) as needed. The specific structure of the cooling mechanism (J1) is the same as that of the supported catalyst synthesis apparatus according to this embodiment.

[0048] In an example of microparticle production using the microparticle synthesis apparatus according to this embodiment, a liquid containing an ethanol-containing aqueous solution as a reducing agent is introduced into the first supply source 3. The reducing agent is then heated to room temperature to 450°C using a heater in the heating and insulation mechanism (I) along the liquid transfer route (A) for transferring the reducing agent, and then transferred to the reaction section (D). A Pd raw material solution and a Ru raw material solution are introduced into the second supply source 1 as liquids containing elements constituting the solid solution microparticles, and transferred to the reaction section (D) via the liquid transfer route (B). The ethanol-containing aqueous solution, the Pd raw material solution, and the Ru raw material solution join together in the reaction section (D), where the Pd raw material and the Ru raw material are simultaneously reduced by the ethanol-containing aqueous solution, while the Pd and Ru elements are combined to form solid solution microparticles. The formed solid solution microparticles are then rapidly cooled to room temperature using the water-cooling mechanism (J2). Rapid cooling prevents sintering between particles. The rapidly cooled solid solution microparticles are collected in the collection section (E) connected to the pressure adjustment mechanism (F), and the boiling of the reducing agent is suppressed by controlling the pressure to 0.1 MPa to 138 MPa. By increasing the pressure, the pressure of the entire apparatus is increased, and the activity of the reaction in the reaction section (D) is improved. [Explanation of symbols]

[0049] 100,200,300,400 Supported catalyst synthesis equipment 500,600,700 Fine particle synthesis equipment A. A liquid transfer route connecting the first supply source and the reaction section B. Liquid transfer route connecting the second supply source and the reaction section C. A liquid transfer route connecting the third supply source and the reaction section (B, C) Shared route with liquid transfer route (B) and liquid transfer route (C) D Reaction section E. Recovery Department F Pressure adjustment mechanism G. Mechanism for transporting liquid in one direction H Stirring mechanism I Heating and insulation mechanism J1,J2 cooling mechanism 1. A second source of liquid containing elements that constitute single metal particles or solid solution particles 2. A third source of liquid containing carrier particles. 3. Primary source of liquid containing reducing agent 4. A fourth supply source for storing a mixed liquid of a liquid containing elements constituting the single metal particles or solid solution particles to be supported and a liquid containing carrier particles. 10a Suction side ball 10b Discharge side ball 11a Suction side piping 11b Discharge side piping 12 plungers 13 Space 14 Stirring blade

Claims

1. at least, a first source of a liquid comprising a reducing agent; a fourth supply source for storing a mixed liquid of a liquid containing elements constituting the single metal particles or solid solution particles to be supported and a liquid containing carrier particles; a reaction section (D) in which the liquid containing the reducing agent and the mixed liquid are joined; a liquid transfer route (A) connecting the first supply source and the reaction section (D); a shared route (B, C) connecting the fourth supply source and the reaction section (D); a recovery section (E) connected to the reaction section (D) via a pipe for recovering the reaction product; The supported catalyst synthesis apparatus further comprises a pressure adjusting mechanism (F) connected to the recovery section (E).

2. 2. The supported catalyst synthesis apparatus according to claim 1, further comprising a mechanism (G) for unidirectionally transporting liquid flowing in either the liquid delivery route (A) or the shared route (B, C), or both.

3. 3. The supported catalyst synthesis apparatus according to claim 1, wherein the shared routes (B, C) have a stirring mechanism (H).

4. 4. The supported catalyst synthesis apparatus according to claim 1, further comprising a heating and heat-retaining mechanism (I) in the liquid transfer route (A).

5. 5. The supported catalyst synthesis apparatus according to claim 1, further comprising a cooling mechanism (J2) between the reaction section (D) and the recovery section (E).

6. 6. The supported catalyst synthesis apparatus according to claim 1, further comprising a cooling mechanism (J1) in the shared route (B, C).

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