JP2009068103A - Apparatus for making fine alloy particles carried - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for obtaining alloy particles which stably carry particulate elements with particle sizes of 2 to 10 nm on the surface of a particulate base material such as carbon. <P>SOLUTION: The apparatus for making fine alloy particles carried includes: a container which accommodates the particulate base material; a first sputtering source which is arranged so as to face the container, includes platinum and has a rectangular shape; a second sputtering source which is arranged adjacent to the first sputtering source and includes an element different from that included in the first sputtering source; a first magnet which is arranged at a side of the first sputtering source opposite to a side of facing to the container; and a second magnet which is arranged at a side of the second sputtering source opposite to a side of facing to the container. The magnetic flux density of a magnetic field in the vicinity of the surface of the first or the second sputtering source is varied by adjusting a distance between the first or the second sputtering source and the first or the second magnet corresponding to the respective sources, or a magnetic force of the first or the second magnet. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an alloy fine particle supporting device for supporting fine particles having a particle size of 10 nm or less on a particulate carrier having a particle size of 1 μm or less, and more specifically to the production of a catalyst that can be used in a direct methanol fuel cell. is there.

  Precious metals such as platinum are used as chemical catalysts in addition to decorative items. For example, automobile exhaust gas purification devices, polymer electrolyte fuel cells, etc. In particular, methanol polymer electrolyte fuel cells using methanol solution as a fuel are capable of operating at low temperatures and are small and lightweight. It has been actively researched for the purpose of application to the power supply of mobile devices. However, further improvement in performance is desired for widespread use. The fuel cell converts chemical energy generated by the electrocatalytic reaction into electric power, and a highly active catalyst is indispensable for high performance.

  Currently, platinum and ruthenium alloys (hereinafter referred to as platinum-ruthenium) are generally used as anode catalysts for fuel cells. However, this fuel cell has an electrocatalytic reaction theoretical voltage of 1.21 V, whereas the voltage loss due to the platinum-ruthenium catalyst is as large as about 0.3 V, and in order to reduce this, the high activity exceeding platinum-ruthenium is high. There is a need for (methanol oxidation activity) anode catalysts. Then, adding other elements to platinum-ruthenium has been studied for the purpose of improving methanol oxidation activity.

  In the conventional sputtering method or vapor deposition method, catalyst fine particles are generally supported on carbon processed into a sheet (hereinafter referred to as carbon paper). In this case, since the vapor deposition is performed only on the surface of the carbon paper, when a few nanometers of catalyst fine particles are supported, the supported amount necessary for power generation cannot be obtained. Further, depending on the deposition conditions, the alloy constituting the catalyst may become a thin film instead of fine particles. In this case, there is a drawback that the surface area of the catalyst is reduced and the power generation performance is further reduced.

  On the other hand, it is known that catalyst fine particles are supported on the carrier fine particles by vapor deposition or sputtering (see, for example, Patent Document 1).

When carbon particles are used as a carrier in this method, the carbon powder is sputtered or vapor-deposited while stirring, but in this case, no substance other than carbon could be found even when observed with an electron microscope. The reason is related to the process of forming metal fine particles by the surface state of the carbon fine particles as the deposition target and the deposited atoms. That is, when a metal is physically vapor-deposited by a vacuum process, the vapor-deposited material is blown off in an atomic form using heat or kinetic energy, and collides with the vapor-deposited material. Therefore, the deposited atoms migrate (free movement on the surface of the carrier) and settle in an energy stable place, and then particles grow in the nucleus and connect to form a polycrystalline film. However, in the case of carbon fine particles having a particle size of 1 μm or less, since there are a large number of defects on the surface, the distance that the deposited atoms can migrate is very short and the probability that nuclei necessary for grain growth are formed is low. Therefore, when carbon powder is vapor-deposited with stirring, the powder moves before the nuclei are formed and the deposited material does not fly. . In order to function as a catalyst, although fine particles having a particle size of 2 nm or more and 10 nm or less must be supported on the surface of the carbon powder, metal atoms are attached to the support surface in the form of atoms as described above. Therefore, it cannot be expected to exert its function as a catalyst.
JP 2005-264297 A

  The present invention has been made in view of the above circumstances, and alloy fine particles for obtaining alloy particles in which fine particles having a particle diameter of 2 nm or more and 10 nm or less are stably supported on the surface of a particulate base material such as carbon. An object is to provide a carrier device.

  In order to achieve the above object, an alloy fine particle supporting device of the present invention includes a support member that accommodates a particulate base material, and a rectangular first sputter that is disposed to face the support member and contains platinum. A source, a second sputtering source disposed adjacent to the first sputtering source and containing an element different from the first sputtering source, and a side of the first sputtering source facing the support member In the apparatus for supporting fine alloy particles, comprising: a first magnet disposed on the opposite side; and a second magnet disposed on the opposite side of the second sputtering source from the side facing the support member. By adjusting the distance between the first or second sputter source and the first or second magnet corresponding thereto, or the magnetic force of the first or second magnet, the first or second magnet is adjusted. The magnetic flux density of the magnetic field near the surface of the sputtering source It is characterized in that to.

  The alloy fine particle supporting device of the present invention includes a support member that accommodates the particulate base material, a rectangular first sputter source that is disposed opposite to the support member and contains platinum, and the first sputtering source. A second sputtering source containing an element different from the first sputtering source, which is alternately arranged adjacent to the sputtering source, and the support member of the first sputtering source and the second sputtering source. And a magnet disposed on the opposite side of the first sputtering source, the second sputter source being in the form of a strip with the longitudinal directions thereof being substantially parallel between the first sputter sources. And moving the first or second sputtering source or the magnet relative to each other in a direction substantially perpendicular to the longitudinal direction of the first or second sputtering source. Alternatively, the second spat It is characterized in that is successively generated in a direction perpendicular to the longitudinal direction of the source.

  Furthermore, the alloy fine particle supporting apparatus of the present invention is the alloy fine particle supporting apparatus according to claim 1 or 2, wherein the particulate base material is a base material mainly composed of carbon.

  Furthermore, an alloy fine particle supporting device of the present invention is the alloy fine particle supporting device according to any one of claims 1 to 3, further comprising a mechanism for changing the position of the first or second magnet. It is characterized by.

  Moreover, the alloy fine particle supporting apparatus of the present invention is the alloy fine particle supporting apparatus according to any one of claims 1 to 4, wherein the second sputter source is between the first sputter sources. It is characterized in that it is formed in a strip shape with the longitudinal direction thereof being substantially parallel.

  Furthermore, an alloy fine particle carrying device of the present invention is the alloy fine particle carrying device according to any one of claims 1 to 5, wherein a third element containing an element different from the first and second sputtering sources is included. The third sputtering source is adjacent to the first sputtering source and / or the second sputtering source.

  Furthermore, the alloy fine particle supporting device of the present invention is the alloy fine particle supporting device according to any one of claims 1 to 6, which is opposite to the side facing the support member of the second sputtering source. A member having a higher magnetic permeability than the second sputtering source is provided on the side.

  Further, the alloy fine particle supporting apparatus of the present invention is the alloy fine particle supporting apparatus according to any one of claims 2 to 7, wherein the moving direction of the first and second sputtering sources or the magnet is constant. It is characterized by reverse after scanning the distance.

  Furthermore, the alloy fine particle supporting apparatus of the present invention is the alloy fine particle supporting apparatus according to any one of claims 2 to 8, wherein the moving directions of the first and second sputtering sources or the magnet are reversed. The thickness of the first sputtering source or the second sputtering source in the vicinity of the region is characterized by being thicker than the thickness of the sputtering source in other regions.

  Furthermore, the alloy fine particle supporting apparatus of the present invention is the alloy fine particle supporting apparatus according to any one of claims 2 to 9, wherein the first sputter source or the second sputter source is in a moving direction. A member selected from the first sputtering source, the second sputtering source, SiO 2, TiO 2, WO 3 and Mn is provided on the side opposite to the side facing the support member in the vicinity of the region where the rotation is reversed. It is said.

  The alloy fine particle carrying device of the present invention is the alloy fine particle carrying device according to any one of claims 1 to 10, wherein the first sputtering source or the second sputtering source moves in a moving direction. A member having a higher magnetic permeability than the first sputtering source or the second sputtering source is provided in the vicinity of the reverse rotation region on the side opposite to the side facing the support member.

  Moreover, the alloy fine particle supporting apparatus of the present invention is the alloy fine particle supporting apparatus according to any one of claims 2 to 11, wherein the moving speed of the first and second sputter sources or the magnet is In the vicinity of the region where the moving directions of the first and second sputtering sources or the magnets are reversed, the moving speed is higher in the other regions.

  In addition, the alloy fine particle supporting apparatus of the present invention is characterized in that, in the alloy fine particle supporting apparatus according to claim 2, the moving direction and moving speed of the magnet are always constant.

  The direct methanol fuel cell of the present invention is characterized in that it contains alloy fine particles produced using the alloy fine particle supporting device according to claims 1 to 13.

  According to the alloy fine particle carrying device of the present invention, a plurality of different sputtering sources can be consumed uniformly and efficiently, and alloy particles having a predetermined particle diameter are formed on the surface of the particulate base material. Can do.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an example of a schematic plan view of a sputtering source used in the alloy fine particle supporting apparatus of the present invention. The sputter source 1 is composed of a rectangular second sputter source 3 similar to the rectangular first sputter source 2, and the first sputter source 2 containing platinum is disposed on both sides and adjacent to the center. A second sputtering source 3 containing other alloy elements is arranged. Near the surface of the first sputtering source 2 and the second sputtering source 3, a magnetic field 4 that supplements plasma is formed. The magnetic flux densities of the magnetic fields 4 near the surfaces of the first sputter source 2 and the second sputter source 3 are different from each other.

  FIG. 2 is an example of a schematic plan view showing a sputtering source used in the apparatus for supporting fine alloy particles of the present invention, a magnet corresponding thereto, and lines of magnetic force. As shown in FIG. 2, the first sputtering source 2 and the second sputtering source 3 are fixed to the back backing plate 21 using a conductive adhesive material such as In or a fixing jig (not shown). Further, below the backing plate 21, a first magnet 23 and a second magnet 24 corresponding to the first and second sputtering sources are arranged.

  The magnetic flux density of the magnetic field of the first sputtering source 2 and the second sputtering source 3 is adjusted by making the first magnet 23 and the second magnet 24 movable. For example, when the sputtering rate of the second sputtering source 3 is higher than that of the first sputtering source 2, the first magnet 23 corresponding to the first sputtering source 2 is moved away and the first sputtering source 2 corresponding to the second sputtering source 2 is moved away. The two magnets 24 are brought close to each other. By this mechanism, the composition of the deposited material can be easily adjusted, and an optimum composition can be obtained even if the material of each sputtering source is changed.

  FIG. 3 is an example of a schematic cross-sectional view of a magnet used in the alloy fine particle supporting apparatus of the present invention. When the magnetic first magnet 23 and the second magnet 24 in FIG. 2 are viewed in cross section, they are composed of a magnet 31 surrounding the outer periphery and a central magnet 32 having a different polarity. When the first magnet 23 and the second magnet 24 are brought close to the first sputtering source 2 and the second sputtering source 3, as shown in FIG. 2, the surfaces of the first sputtering source 2 and the second sputtering source 3. Magnetic field lines 22 occur in the vicinity, thereby increasing the trapping density of the plasma, so that a magnetic field as shown by 4 in FIG. 1 is formed. Although the sputtering rate varies depending on the material, it depends on the magnetic flux density and varies depending on the cross-sectional areas of the first magnet 23 and the second magnet 24, the magnetic force, and the distance R from the sputtering source.

  The arrangement of the first sputtering source 2 and the second sputtering source 3 and the formation of the magnetic field include methods as shown in FIGS.

  In FIG. 4, the magnitude relationship of the magnetic flux density of the magnetic field 4 of each of the first sputter source 2 and the second sputter source 3 is reversed as compared with FIG. 1, and the first sputter source 2 and the first sputter source corresponding to this. By increasing the distance R of the magnet 23 and decreasing the distance R between the second sputter source 3 and the second magnet 24 corresponding thereto, the magnetic field is expanded to increase the utilization efficiency of the raw material.

  Further, in FIG. 5, the third sputtering source 51 containing ruthenium or the like and the second sputtering source 3 are arranged between the first sputtering source 2 and the second sputtering source 3 so that the longitudinal directions thereof are parallel to each other. Is. The magnetic flux density of the magnetic field 4 is set so that the distance R between the first sputter source 2 and the second sputter source 3 and the first magnet 23 and the second magnet 24 corresponding to the first sputter source 2 and the second sputter source 3 can be obtained. adjust. Since the first sputter source 2, the second sputter source 3, and the third sputter source 51 are made of a single element without being alloyed, each sputter source is used again as a raw material. Rework costs are reduced. Note that a magnet corresponding to the third sputtering source 51 is not particularly provided.

  Further, as shown in FIG. 6, the third sputtering source 51 can be arranged at the center of the second sputtering source 3 so that the longitudinal direction is substantially parallel. In this case, the variation in the composition of the deposited material can be further reduced.

  Further, as shown in FIG. 7, the third sputter source 51 is arranged in the center of the second sputter source 3 so that the longitudinal direction thereof is substantially orthogonal, and the third sputter source 51 is connected to the first sputter source 2. It can also arrange so that it may touch.

  When a small sputtering source 1 is used, as shown in FIG. 8, one continuous magnetic field 4 straddling the first sputtering source 2, the second sputtering source 3, and the third sputtering source 51 is applied to the entire sputtering source. You may form over. In this case, a magnet having a size corresponding to the entire sputtering source 1 is prepared.

  Conversely, when the sputtering source 1 is slightly larger, a plurality of magnetic fields 4 shown in FIG. 8 may be formed as shown in FIG. Thereby, the sputtering rate can be increased and the utilization efficiency of the raw material can be increased.

  In addition, in the case of obtaining a catalyst having a high composition ratio of the first sputter source 2, a plurality of magnetic fields 4 are provided as shown in FIG. 10, and a part of the continuous magnetic field 4 is the second sputter source 3 and the second sputter source 3. 3 sputter sources 51 may be formed.

  By the way, in the magnetron sputtering method, a new raw material is replaced immediately before a hole is opened in the erosion region of the sputtering source (a range in which the constituent elements are repelled by the sputtering phenomenon and the sputtering source is consumed), and the remaining material is subjected to a regeneration process. There is. Usually, since the sputtering speed in the erosion region is two orders of magnitude or more faster than the surroundings, the ratio of the raw materials that can be used for sputtering is extremely about 10% to 20% because only that region is extremely lost. Therefore, it is necessary to frequently perform the regeneration process, and the influence of the product on the cost becomes large.

  FIG. 11 is an example of a schematic plan view showing a sputtering source and a magnetic field used in the alloy fine particle supporting apparatus of the present invention.

  In the present invention, in order to improve the utilization efficiency of the sputtering source, as a sputtering source for mass production, as shown in FIG. 11, the first sputtering source 2 containing platinum and the second sputtering source 3 are alternately arranged in the longitudinal direction. Are formed in parallel, and the magnetic field is formed in a band shape or a rectangular shape so as to be substantially orthogonal to the longitudinal direction thereof, and the sputter source 1 as a whole and a magnet corresponding to the first sputter source 2 are relatively shown although not shown. Alternatively, the second sputtering source 3 is moved in the longitudinal direction, and sputtering is performed while sequentially scanning.

  By using the sputter source 1 as described above, even if the input power during sputtering is the same, the composition of the deposited material can be adjusted without using the sputter source of the alloy while appropriately adjusting the magnetic flux density according to the sputtering speed or the binding energy of the material. Can be controlled. The remaining material of the sputter source 1 that has been locally scraped and becomes unusable is melted and reprocessed. However, if the first sputter source 2 and the second sputter source 3 are not mixed with other elements. It is preferable because it is easy to rework, and the regeneration cost can be suppressed, resulting in efficient sputtering.

  FIG. 12 is a cross-sectional view of the AA plane of FIG. 11, which is an example showing the positional relationship between the sputtering source and the magnet corresponding thereto.

  As shown in FIG. 12, the position of the magnet 121 can be adjusted in advance with respect to the first sputtering source 2 and the second sputtering source 3, and sputtering can be performed while scanning. In the case of FIG. 12, the scanning direction is the front and back direction with respect to the paper surface.

  13 to 17 show modified examples of the sputtering source when sputtering is performed while sequentially scanning the entire sputtering source 1 and the magnet corresponding to the entire movement.

  FIG. 13 is substantially the same as FIG. 11, and the magnetic field 4 is formed in the vicinity of the surface in the entire sputtering source 1 in a band shape or a rectangular shape, but the end 131 is always on the second sputtering source 3. Since the end portion 131 has a high sputtering rate, it is necessary to replace the raw material as appropriate.

  FIG. 14 is substantially the same as FIG. 13, but the magnetic flux density at the end portion 141 of the magnetic field 4 is slightly reduced. The magnetic flux density at the end may be adjusted by any one of these methods by reducing the magnetic force of the magnet, increasing the distance from the backing plate, or removing the magnet. This scanning does not require frequent replacement of specific raw materials, improving productivity.

  FIG. 15 is a diagram in which the first sputtering source 2 is disposed at both longitudinal ends of the first sputtering source 2 and the second sputtering source 3. The time during which the scanned magnetic field 4 stays in the same place is reduced as much as possible. If it does so, the utilization efficiency of a noble metal raw material can further be improved, maintaining the uniformity of a composition of a deposit.

  In FIG. 16, the first sputter source 2 and the second sputter source 3 are arranged so that the longitudinal directions thereof are substantially parallel, and the outer periphery of the first sputter source 2 and the second sputter source 3 has a lower sputter rate than that of the first sputter source 2 by one digit or more. 161. Examples thereof include silicon oxide, titanium oxide, zirconium oxide, tungsten oxide, and molybdenum oxide. The metal elements constituting these have an effect of improving the activity of the catalyst, and even if it is a metal oxide, there is no adverse effect as long as it is a trace amount. Alternatively, it may be composed of a polymer compound, and in particular, Teflon (R) is preferable because it has a high crystallinity and less monomer dissociation.

  In this case, it is desirable to move the magnetic field to the member 161 region having a low sputtering speed as shown in FIG. 17 because the thickness of the entire sputtering source 1 is reduced uniformly. At this time, a part of the first sputtering source 2 and the second sputtering source 3 may evaporate once and then adhere to the surrounding member 161 having a low sputtering rate. However, they can be sputtered again. Therefore, the utilization efficiency of the noble metal material can be improved.

  As an example for efficiently using the sputtering source, as shown in FIG. 21, a member having a high magnetic permeability can be provided on the side opposite to the side facing the support member of the second sputtering source. That is, a member 213 having a high magnetic permeability is provided between the material 212 having a high sputtering rate and the magnet 215. Specifically, the member 213 having a high magnetic permeability is selected from Ni, Fe, and Co, and is held in the backing plate 214. The member 213 having a high magnetic permeability can be set to a desired thickness depending on the sputtering speed, and the strength of the magnetic field can be adjusted.

  In order to increase the productivity of alloy fine particles, it is conceivable to provide a plurality of erosion regions. In other words, when the scanning of the two magnets 215 is considered as an example, the scanning direction must be reversed near the center in the longitudinal direction of the sputtering sources 211 and 212. The problem here is that when the scanning direction is reversed, since the scanning of the magnet 215 stops once, the sputtering time near the center in the longitudinal direction becomes longer, and the degree of wear of the sputtering sources 211 and 212 is higher than in other regions. To be higher. If the sputtering time becomes long, it is conceivable that holes are formed in the sputtering sources 211 and 211.

  Therefore, as shown in the BB cross-sectional view of FIG. 21, a member 213 having a high magnetic permeability is installed in the direction perpendicular to the center of the sputter sources 211 and 212 in the longitudinal direction. Alternatively, by setting the sputtering rate near the center in the longitudinal direction of the sputtering sources 211 and 212 to be 80% or more and 95% or less of the other regions, the degree of wear of the entire sputtering sources 211 and 21 can be made constant. Efficient use.

  If it is less than 80%, the difference between the portion with and without the high-permeability member 213 is large, and it is not preferable because a clear boundary is formed. If it exceeds 95%, it stops to reverse the magnet scanning direction. Since the driving time is short, high accuracy is required for the driving device, which increases the cost, which is not preferable. More preferably, it is more effective to change continuously within the above range. That is, as the distance from the center in the vicinity of the center in the longitudinal direction of the sputtering sources 211 and 212 is decreased, the reduction rate of the sputtering rate is reduced. Specifically, the thickness of the member 213 having a high magnetic permeability provided near the center in the longitudinal direction of the sputtering sources 211 and 212 is reduced as the distance from the center increases. Thereby, a sputtering source can be used more uniformly.

  Further, as shown in FIG. 22, in the region A where the scanning directions of the plurality of magnets 221 are reversed, it is conceivable that the moving speed of the magnet 221 is made 5% or more and 10% or less faster than the other regions B.

  If it is less than 5%, the time during which the magnet is stopped to reverse the scanning direction of the magnet is short, so that high accuracy is required for the driving device, which is not preferable. It is not preferable.

  Further, as shown in FIG. 23, the thickness near the center of the sputtering source 233 can be made thicker than other regions. The standard for the thickness depends on the time during which the magnet is stopped to reverse the scanning direction of the magnet and the sputtering speed, and the thickness near the center is about 1.1 to 1.3 times that of other regions. preferable.

  Furthermore, as shown in FIG. 24, a plate-like member 244 selected from the same material as that of the sputtering source 243, SiO2, TiO2, WO3, and Mn can be provided near the center of the sputtering source 243. By this member 244, sputtering can be continued even if a hole is formed in a part of the sputtering source 243.

  In addition, as shown in FIG. 25, an apparatus that scans the plurality of sputtering sources 253 in one direction like a belt conveyor by installing a plurality of sputtering sources 253 on the base 254 and rotating the rotating roller 255 is also conceivable. With this apparatus, the degree of wear of the sputtering source 253 is suppressed, and sputtering can be performed for a long time.

  By the way, in the alloy fine particle supporting apparatus of the present invention, as shown in FIG. 26, by changing the distance L between the plurality of sputtering sources 263, 264, 265 and the particulate base material 266 mainly composed of carbon, Distribution can be applied to the concentration of alloy fine particles in the plane of the material 266. FIG. 27 shows the relationship between the position and the deposition rate obtained when a sputtering source in which three different materials are periodically arranged is used. Here, when the first sputter source 263 is Pt, the second sputter source 264 is Ru, and the third sputter source 265 is WMo, when L is 10 mm, the deposition rate is 100 nm / min. However, immediately below Ru, 20 to 40 nm / min. To fall. It was confirmed that the difference in the deposition rate depending on the location became smaller as L was increased.

  Now, it may be better that the particulate base material or the sheet-like base material has a concentration distribution of alloy fine particles.

  For example, FIG. 28 shows a direct methanol fuel cell (hereinafter referred to as DMFC) called an active system. In the DMFC 281, methanol and water necessary for power generation are sent to the cell 282 by the fuel pump 286 from the fuel tank 284 and the water tank 285 that are respectively provided at an appropriate mixing ratio.

  FIG. 28 shows a cross-sectional view of the inside of the DMFC cell. In the cell 291, a flow path is provided in the anode 292 and the cathode 293, and mixed fuel flows in the anode 292 and air flows in the cathode 293. In the meantime, methanol is used for power generation, so the concentration of methanol is high near the fuel inlet 294, and the concentration decreases as the fuel outlet 295 is approached. Water generated during power generation is returned to the water tank 285 and reused.

  It is important in terms of power generation efficiency, life, etc. that the DMFC electrode has a catalyst amount that matches the methanol concentration. Therefore, a membrane / electrode assembly (MEA) 298 having an increased amount of catalyst near the fuel inlet 294 and decreasing as the fuel outlet 295 is approached is advantageous for this method.

  Such an electrode tends to be produced by changing the thickness of the catalyst layer even in the conventional wet method, but the thickness of the catalyst layer affects the diffusion characteristics of the fuel, so the characteristics deteriorate. Realization is difficult. On the other hand, in the present invention, the alloy fine particles can be easily changed in the plane without changing the thickness of the catalyst layer. Specifically, the amount (mixing ratio) of Ru and Hf, Ta, Mo, W, Ni, Si and other additive elements with respect to Pt can be changed. As the amount of Pt decreases, the amount of Ru and other elements increases. However, depending on the additive element, it is preferable because the power generation efficiency becomes higher with respect to low concentration methanol fuel.

Example 1
In this embodiment, the areas of the first and second sputtering sources having a rectangular shape and the positions of the respective sputtering sources and the magnets corresponding thereto are set so that platinum and tungsten have a sputtering rate of 4: 1. Adjusted. Specifically, since tungsten has a slightly higher sputter rate than platinum, the area is 1: 2, and the magnetic flux density near the surface of the second magnet corresponding to the second sputter source is used as the first sputter source for platinum. 80% compared to the corresponding first magnet.

FIG. 18 is a schematic cross-sectional view when sputtering is performed on a particulate base material using the sputtering source 181 formed as described above. A support containing a particulate matrix 182 whose base is carbon having an average particle diameter of 1 μm or less and a surface area of 50 m ² / g or more so as to face under the formed sputtering source 181 (a magnet corresponding to the sputtering source is not shown). The member 183 was placed, and sputtering was performed for 10 hours under the following conditions. At this time, a rotor 186 in which Teflon (registered trademark; manufactured by DuPont) is coated on a magnetic material previously placed in a support member by using a magnetic stirrer 185 installed outside the vacuum chamber 184 is fixed at regular intervals. The particulate matrix was stirred by rotating for a period of time.

Pressure: 1 × 10 ⁻² Pa
Time not stirred; 100 seconds stirring time; 5 seconds deposition amount; 1 × 10 ¹⁵ atoms / cm ² · second

As a result, 100 g of a platinum-tungsten catalyst-supported carbon powder having a loading ratio (weight of catalyst with respect to the weight of carbon) of 50% was produced.

  FIG. 19 is a schematic diagram of a membrane / electrode composite for catalyst evaluation according to an example of the present invention. FIG. 20 shows a schematic diagram of a single cell of a direct methanol fuel cell incorporating the membrane-electrode assembly.

Using the obtained powder, a cathode electrode 191 and an anode electrode 192 were respectively produced, and a proton conductive solid polymer membrane 193 made of Nafion (registered trademark; manufactured by DuPont) between the cathode electrode 191 and the anode electrode 192. The membrane / electrode assembly (MEA) was produced by thermocompression bonding at 125 ° C. for 10 minutes at a pressure of 30 kg / cm 2. A single cell of a direct methanol fuel cell was fabricated using this membrane / electrode composite, the flow path plate 201, the fuel permeation section 202, the vaporization section 203, the separator 204, and the lead wire 205. In this single cell, a 1M aqueous methanol solution as a fuel, a flow rate of 0.6 ml / min. In addition to supplying to the anode electrode 192, air was supplied to the cathode electrode 191 at a flow rate of 200 ml / min, and the cell was discharged to maintain a current density of 150 mA / cm ² while maintaining the cell at 65 ° C. When the cell voltage was measured, a voltage of 0.6 V was obtained. The obtained voltage was 20% or more higher than that produced with the same amount of noble metal. Thus, when produced by a vacuum process, since the sputtered ruthenium is not oxidized, there is little elution by formic acid generated during the power generation process, and it is considered that there is little deterioration in characteristics when used for a long time. The platinum and tungsten sputtering sources were consumed almost uniformly and could be efficiently carried on the deposited material. Moreover, it was easy to rework the sputtering source. The average particle size of the obtained alloy particles was 4 nm.

(Example 2)
In the following examples, parts different from those in Example 1 were mainly described, and the same mechanism as Example 1 was omitted. In Example 1, the magnetic flux density near the surface of the sputtering source was changed in advance by changing the magnetic force of the magnet in accordance with the composition of the catalyst and the constituent elements of the alloy. The magnetic flux density was adjusted by the mechanism shown in FIG. As the sputtering source, platinum and niobium were selected, and an alloy having a platinum to niobium ratio of 4: 1 was supported. Since the sputtering rate of niobium was faster than that of platinum, the area of the sputtering source was halved and the magnet was separated from the backing plate by 10 mm so that the magnetic flux density was 30% smaller. As for other conditions, sputtering was performed for 10 hours in the same manner as in Example 1 and evaluated by a single cell. As a result, a voltage of 0.6 V was obtained. This is a value that is 20% or more higher than that produced with the same amount of noble metal. The platinum and niobium sputtering sources were consumed almost uniformly and could be efficiently carried on the deposit. In addition, the sputtering source could be easily reworked. The average particle size of the obtained alloy particles was 4 nm.

(Example 3)
In Example 1 and Example 2, the raw material was replaced with a new material immediately before a hole was opened in the erosion region of the sputtering source, and the remaining material was regenerated. In this example, the configuration shown in FIG. 11 was adopted in order to increase the utilization efficiency of raw materials. The sputtering source was a first sputtering source containing platinum and a second sputtering source containing vanadium. Other conditions were the same as in Example 1, and sputtering was performed for 20 hours. When evaluated with a single cell, a voltage of 0.6 V was obtained. This is a value that is 20% or more higher than that produced with the same amount of noble metal. As a result, power generation efficiency has also improved. On the other hand, the rectangular plate material was also sputtered almost uniformly, and the utilization efficiency could be increased to 80% or more. The platinum and vanadium sputtering sources were consumed almost uniformly and could be efficiently carried on the deposited material. The utilization efficiency of platinum and vanadium could be increased, and rework of precious metal materials was easy. The average particle size of the obtained alloy particles was 4 nm.

  According to the present invention, it is possible to provide a method and an apparatus for supporting fine particles having a particle size of 10 nm or less on a particulate carrier having a particle size of 1 μm or less, and the use includes a direct methanol fuel cell using the powder as a catalyst. .

The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic sectional drawing which shows an example of the sputtering source of the alloy fine particle supporting apparatus which can be used by this invention, and the magnet according to this. The schematic plan view which shows an example of the magnet of the alloy fine particle support apparatus which can be used by this invention. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic sectional drawing which shows an example of the sputtering source of the alloy fine particle supporting apparatus which can be used by this invention, and the magnet according to this. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic plan view which shows an example of arrangement | positioning of a sputter | spatter source of an alloy fine particle support apparatus which can be used by this invention, and a magnetic field. The schematic sectional drawing which shows an example of the alloy fine particle support apparatus which can be used by this invention. Schematic sectional view of a membrane / electrode composite according to an embodiment of the present invention 1 is a schematic cross-sectional view of a single cell of a direct methanol fuel cell according to an embodiment of the present invention. The schematic plan view and schematic sectional drawing which show an example of the sputtering source of the alloy fine particle supporting apparatus which can be used by this invention, and a magnet according to this. The schematic sectional drawing which shows an example of the sputtering source of the alloy fine particle supporting apparatus which can be used by this invention, and the magnet according to this. The schematic sectional drawing which shows an example of the sputtering source of the alloy fine particle supporting apparatus which can be used by this invention, and the magnet according to this. The schematic sectional drawing which shows an example of the sputtering source of the alloy fine particle supporting apparatus which can be used by this invention, and the magnet according to this. The schematic sectional drawing which shows an example of the sputtering source of the alloy fine particle supporting apparatus which can be used by this invention, and the magnet according to this. The schematic sectional drawing which shows the distance of the sputter | spatter source of the alloy fine particle support apparatus which can be used by this invention, and a particulate-form base material. The figure which shows the relationship between the distance of the sputter | spatter source of the alloy fine particle support apparatus which can be used by this invention, a particulate-form base material, and the deposition rate. The schematic diagram of a direct methanol type fuel cell. The schematic cross section of the cell for direct methanol type fuel cells.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sputter source 2 1st sputter source 3 2nd sputter source 4 Magnetic field 21 Backing plate 22 Magnetic field line 23 1st magnet 24 2nd magnet 31 Magnet 32 Magnet 51 3rd sputter source 121 Magnet 131 End 141 of a magnetic field Magnetic field 161 having a slightly low magnetic flux density Low sputtering rate material 181 Sputter source 182 Particulate base material 183 Support member 184 Vacuum chamber 185 Magnetic stirrer 186 Magnetic rotor 191 Cathode electrode 192 Anode electrode 193 Proton conducting solid polymer film 201 Flow Road plate 202 Fuel permeation section 203 Vaporization section 204 Separator 205 Lead wires 211, 263 First sputter source 212, 264 Second sputter source 213 Highly permeable members 214, 222, 232, 242, 252, 262 Backing plate 215 , 221, 2 1, 241, 251, 261 Magnet 223, 233, 243, 253 Sputter source 244 Plate member 254 Base 255 Rotating roller 265 Third sputter source 266 Particulate base material 267 Support member 281 Direct methanol fuel cells 282, 291 Direct methanol fuel cell 283 Air pump 284 Fuel tank 285 Water tank 286 Pump 292 Anode 293 Cathode 294 Fuel inlet 295 Fuel outlet 296 Air inlet 297 Air outlet 298 Membrane / electrode complex

Claims (14)

A support member for accommodating the particulate base material or the sheet-like base material;
A rectangular first sputter source disposed opposite to the support member and containing platinum;
A second sputter source disposed adjacent to the first sputter source and containing an element different from the first sputter source;
A first magnet disposed on a side opposite to the side facing the support member of the first sputtering source;
A second magnet disposed on the opposite side of the second sputtering source from the side facing the support member;
In an apparatus for supporting fine alloy particles comprising:
By adjusting the distance between the first or second sputtering source and the corresponding first or second magnet, or the magnetic force of the first or second magnet,
An apparatus for supporting alloy fine particles, wherein a magnetic flux density of a magnetic field in the vicinity of the surface of the first or second sputtering source is changed. A support member for accommodating the particulate base material or the sheet-like base material;
A rectangular first sputter source disposed opposite to the support member and containing platinum;
A second sputter source containing elements different from the first sputter source, alternately disposed adjacent to the first sputter source;
A magnet disposed on a side of the first sputtering source and the second sputtering source opposite to the side facing the support member;
In an apparatus for supporting fine alloy particles comprising:
The second sputter source is formed in a strip shape between the first sputter sources, with each longitudinal direction being substantially parallel.
By relatively moving the first or second sputtering source or the magnet in a direction substantially perpendicular to the longitudinal direction of the first or second sputtering source,
An alloy fine particle supporting apparatus, wherein the magnetic field is sequentially generated in a direction orthogonal to a longitudinal direction of the first or second sputtering source. 3. The alloy fine particle supporting device according to claim 1, wherein the particulate base material or the sheet-like base material is a base material mainly composed of carbon. The alloy fine particle carrier device according to any one of claims 1 to 3, further comprising a mechanism for changing a position of the first or second magnet. The second sputtering source is formed in a strip shape between the first sputtering sources with their longitudinal directions substantially parallel to each other. The alloy fine particle carrying device according to 1. A third sputter source containing an element different from the first and second sputter sources;
6. The alloy fine particle supporting apparatus according to claim 1, wherein the third sputtering source is adjacent to the first sputtering source and / or the second sputtering source. 7. The member according to claim 1, wherein a member having a magnetic permeability higher than that of the second sputtering source is provided on a side opposite to the side facing the support member of the second sputtering source. 2. The alloy fine particle supporting apparatus according to item 1. 8. The alloy fine particle carrier according to claim 2, wherein the moving directions of the first and second sputtering sources or the magnets are reversed after scanning a predetermined distance. 9. . The thickness of the first sputter source or the second sputter source in the vicinity of the first and second sputter sources or the region where the moving direction of the magnet is reversed is greater than the thickness of the sputter source in the other regions. The apparatus for supporting fine alloy particles according to any one of claims 2 to 8, wherein the apparatus is also thick. The first sputter source or the second sputter source is located on the opposite side to the side facing the support member in the vicinity of the region where the moving direction is reversed. 10. The alloy fine particle supporting device according to claim 2, wherein a member selected from SiO2, SiO2, TiO2, WO3 and Mn is provided. The first sputter source or the second sputter source is located on the opposite side to the side facing the support member in the vicinity of the region where the moving direction is reversed. The alloy fine particle supporting device according to any one of claims 1 to 10, wherein a member having a higher magnetic permeability is provided. The moving speed of the first and second sputter sources or the magnet is greater than the moving speed in other areas in the vicinity of the area where the moving direction of the first and second sputter sources or the magnet is reversed. 12. The alloy fine particle carrying device according to claim 2, wherein the alloy fine particle carrying device is any one of claims 2 to 11. 3. The alloy fine particle supporting device according to claim 2, wherein the moving direction and moving speed of the magnet are always constant. 14. A direct methanol fuel cell, comprising alloy fine particles produced by using the alloy fine particle supporting apparatus according to claim 1.

Images