Carrier and method for manufacturing a carrier

Abstract

To provide a cluster supporting body that has high activities and allows for industrial mass-production.SOLUTION: A supporting body includes a cluster of an alloy containing Pt and Co, and a support on which the cluster is supported. The amount of Pt supported is 1×10-14 ng / cm2 or more and 1×105 ng / cm2 or less. The cluster supporting body can be easily produced, allowing for industrial mass-production. The cluster supporting body has high mass activities (catalytic activities), significantly surpassing the mass activities of the standard catalyst (TEC10E50E).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to a carrier and a method for manufacturing a carrier. [Background technology]

[0002] Platinum (Pt) is widely used as an electrode catalyst in fuel cells. However, Pt is an extremely expensive precious metal. Moreover, Pt reserves are insufficient. Therefore, in order to reduce the cost of fuel cells and to realize their widespread adoption, it is important to improve catalytic activity and reduce the amount of Pt used. To date, a technology has been disclosed in which Pt nanoparticles or the like, contained within a predetermined dendrimer (dendritic polymer), are supported on a porous carbon material and used as a catalyst (see Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2013-159588 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the carrier obtained using the above technology had the following three industrial disadvantages. In other words, (1) The synthesis of dendrimers requires various reagents (including organic solvents), which is industrially disadvantageous. (2) First of all, the technology for mass-producing dendrimers has not yet been established. (3) A separate process is required to combine the synthesized Pt particles with the carbon material, which is complicated. This disclosure has been made in view of the above circumstances and aims to provide a carrier on which clusters are supported, which can be mass-produced industrially. Furthermore, the present invention is expected to have applications in a wide range of fields. This disclosure can be implemented in the following forms: [Means for solving the problem]

[0005] [1] A support comprising clusters of an alloy containing Pt and Co supported on a carrier, The amount of Pt loaded is 1 × 10⁻⁶ -14 ng / cm 2 The above 1 x 10 5 ng / cm 2 The carrier is as follows.

[0006] [2] The carrier is the carrier described in [1], wherein the carrier is made of a conductive material.

[0007] [3] The carrier according to [1] or [2], wherein the composition of the cluster is one or more selected from the group consisting of Pt4Co2, Pt5Co, Pt6Co2, Pt7Co2, and Pt8Co.

[0008] A manufacturing method for producing the carrier described in [4] [1], The generation step for generating the aforementioned cluster, A supporting step of landing and supporting the cluster on the carrier, A method for manufacturing a carrier, comprising the following:

[0009] [5] The system includes a sorting step for selecting specific mass clusters having a specific mass range from among the clusters, The method for manufacturing a carrier according to [4], wherein the loading step involves landing the specific mass clusters onto the carrier. [Effects of the Invention]

[0010] The carrier material of this disclosure can be manufactured relatively easily and therefore can be mass-produced industrially. The method for manufacturing the support material described herein is simpler than conventional methods and is suitable for industrial mass production. [Brief explanation of the drawing]

[0011] Regarding the present disclosure, non-limiting examples of typical embodiments according to the present invention will be given and further described in the following detailed description while referring to the plurality of drawings mentioned. [Figure 1] It is a conceptual diagram showing an example of an apparatus for implementing a method for manufacturing a cluster carrier.

Embodiments for Carrying Out the Invention

[0012] The matters shown here are illustrative and for exemplarily explaining the embodiments of the present invention, and are described for the purpose of providing an explanation that is considered to be the most effective and easy to understand for the principles and conceptual features of the present invention. In this regard, it is not intended to show the structural details of the present invention more than necessary for a fundamental understanding of the present invention, and it is to clarify to those skilled in the art how some forms of the present invention are actually embodied by the description in combination with the drawings.

[0013] Hereinafter, the present disclosure will be described in detail. In this specification, for a description using "~" for a numerical range, unless otherwise specified, it includes the lower limit value and the upper limit value. For example, in the description "10~20", both the lower limit value "10" and the upper limit value "20" are included. That is, "10~20" has the same meaning as "10 or more and 20 or less".

[0014] 1. Carrier The carrier is formed by supporting clusters of an alloy containing Pt and Co on a carrier. The supported amount of Pt is 1×10 -14 ng / cm 2 or more and 1×10 5 ng / cm 2 or less.

[0015] (1) Elements Constituting the Cluster The cluster is made of an alloy containing Pt (platinum) and Co (cobalt) from the perspective of practicality. The alloy may contain, as other elements besides Pt and Co, elements that can constitute a conductive material. Other elements can be preferably exemplified by one or more selected from the group consisting of Au (gold), Ag (silver), Pd (palladium), Ni (nickel), Si (silicon), Ge (germanium), Sn (tin), In (indium), Cd (cadmium), Zn (zinc), W (tungsten), Ta (tantalum), Cu (copper), Ru (ruthenium), Ir (iridium), Cr (chromium), Fe (iron), V (vanadium), Mn (manganese), Y (yttrium), Tc (technetium), Ga (gallium), Nb (niobium), Mo (molybdenum), Zr (zirconium), Rh (rhodium), Os (osmium), Re (rhenium), Al (aluminum), and Ti (titanium).

[0016] (2) Composition of the cluster The composition of the cluster is not particularly limited as long as it contains Pt (platinum) and Co (cobalt). From the perspective of high mass activity, the composition of the cluster is preferably one or more selected from the group consisting of Pt4Co2, Pt5Co, Pt6Co2, Pt7Co2, and Pt8Co. Note that the cluster in this disclosure is a nanocluster or a sub-nanocluster. The form of the cluster is not particularly limited, but for example, it is in a form where Pt atoms and Co atoms are aggregated in a ratio corresponding to the above composition.

[0017] (3) Loading amount of Pt (platinum) The loading amount of Pt is 1×10 -14 ng / cm 2 or more and 1×10 5 ng / cm 2 or less. When the loading amount is within this range, the activity when using the support as a catalyst tends to be high. The loading amount of Pt (platinum) is 1×10 -14 ng / cm 2 or more and 1×10 5 ng / cm 2The reason for the high mass activity in the following cases is presumed to be due to the increased specific surface area resulting from miniaturization. Note that "mass activity" refers to the mass activity (oxygen reduction current density per gram of Pt) for the oxygen reduction reaction (ORR) (the same applies hereafter).

[0018] (4) Mass activity The mass activity of a support in which alloy clusters are supported on a carrier is preferably greater than 300 A / g, more preferably 400 A / g or more, even more preferably 500 A / g or more, even more preferably 600 A / g or more, and even more preferably 700 A / g or more. Typically, the upper limit of mass activity is 2 × 10⁻⁶. 4 It is A / g. When the mass activity falls within this range, it is useful as an electrode catalyst for fuel electrodes and the like.

[0019] (5) Carrier The carrier is not particularly limited. Examples include carbon, titanium oxide, bismuth telluride, bismuth selenium, aluminum, constantan, gold, silver, copper, brass, platinum, nichrome, iron, titanium, tungsten, tungsten oxide, indium tin oxide, strontium titanate, molybdenum, zinc, nickel, tin, lead, silicon, silicon carbide, stainless steel, magnesium, cobalt, lithium, chromium, manganin, polyaniline, poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) [PEDOT / PSS], polyacetylene, polythiophene, polypyrrole, polyphenylene vinylene, polythiophenylene vinylene, and ionic liquids. Furthermore, among these examples, those that can be doped with other elements are also included if they are doped with other elements.

[0020] 2. Method for manufacturing the carrier The method for manufacturing the support is not particularly limited. Here, a preferred method for manufacturing the support is described. The method for manufacturing this carrier comprises a generation step of generating clusters and a carrying step of landing and supporting the clusters on a carrier.

[0021] (1) Generation process In the generation process, there are no particular limitations on the generation method that generates (generates) clusters, and a wide range of methods can be employed. For example, magnetron sputtering, ion sputtering, ion beam sputtering, and laser evaporation can be used. Among these, magnetron sputtering is preferred from the viewpoint of ion quantity and stability. From the viewpoint of efficient catalytic reaction, the clusters generated in the production process preferably have 2 to 100 atoms, and more preferably 3 to 80 atoms.

[0022] The elements constituting the cluster ion include at least Pt (platinum) and Co (cobalt). Other elements constituting the cluster ion may include elements that can constitute conductive materials. Other elements are preferably conductive to the target in the DC magnetron sputtering method, and suitable examples include one or more selected from the group consisting of Au (gold), Ag (silver), Pd (palladium), Ni (nickel), Si (silicon), Ge (germanium), Sn (tin), In (indium), Cd (cadmium), Zn (zinc), W (tungsten), Ta (tantalum), Cu (copper), Ru (ruthenium), Ir (iridium), Cr (chromium), Fe (iron), V (vanadium), Mn (manganese), Y (yttrium), Tc (technetium), Ga (gallium), Nb (niobium), Mo (molybdenum), Zr (zirconium), Rh (rhodium), Os (osmium), Re (rhenium), Al (aluminum), and Ti (titanium). Furthermore, laser evaporation and high-frequency magnetron sputtering methods can generate cluster ions regardless of whether the target is conductive or not.

[0023] (2) Carrying process In the loading process, the clusters are landed on a carrier and loaded onto it. The description in "1.(5) Carrier" above can be applied directly to the carriers that support the clusters. The landing of the cluster onto the carrier is a so-called soft landing; that is, a collision energy of 1 eV / atom or less is preferred. By performing a soft landing in this way, the destruction of the cluster can be suppressed.

[0024] (3) Other processes A method for manufacturing a carrier may include a sorting step for selecting specific mass clusters having a specific mass range from among the clusters. By including this sorting step, specific mass clusters will land on the carrier. This sorting step ensures that specific mass clusters are supported on the carrier, improving the usability of the carrier.

[0025] The sorting process is not particularly limited. Preferably, the sorting process uses an ion deflector and a quadrupole mass spectrometer. Ions in a specific charge state can be sorted using the ion deflector, and clusters of a specific size can be sorted using the quadrupole mass spectrometer.

[0026] (4) An example of an apparatus for carrying out a method for manufacturing cluster carriers Here, an example of a manufacturing apparatus 7 for cluster carriers that implements the above manufacturing method is described (Figure 1). The cluster carrier manufacturing apparatus 7 includes a cluster generation apparatus 10. The cluster generation apparatus 10 includes a vacuum chamber 11, a cluster growth cell 12 installed in the chamber 11, and a sputtering source 13 (magnetron sputtering source) installed in the cluster growth cell 12. The cluster growth cell 12 is surrounded by a liquid nitrogen jacket 14, and liquid nitrogen (N2) is configured to flow through the liquid nitrogen jacket 14. The cluster generation apparatus 10 further includes a control device 15 and a pulse power supply 16 for the sputtering source as components of the control system.

[0027] The cluster generator 10 includes a first inert gas supply pipe 17 and a second inert gas supply pipe 18. The first inert gas supply pipe 17 supplies a first inert gas (e.g., argon gas (Ar)) to the sputter source 13 for generating plasma. The second inert gas supply pipe 18 supplies a second inert gas (e.g., helium gas (He)) into the cluster growth cell 12 for cooling and condensing metal atoms and metal ions generated from the sputter source 13 and growing them as clusters. The main part of the second inert gas supply pipe 18 is housed in a liquid nitrogen jacket 14, and it spirals around the inside of the liquid nitrogen jacket 14, with its end protruding into the inside of the cluster growth cell 12.

[0028] In this way, a second inert gas, such as helium cooled by liquid nitrogen, can be introduced into the cluster growth cell 12. The pressure inside the cluster growth cell 12 is maintained at approximately 10 to 40 Pa. Note that devices such as the pressure gauge provided in the cluster growth cell 12 and the mass flow controller provided in the gas supply system for pressure control are not shown in the illustration. The cluster generator 10 is further equipped with an exhaust system 19 consisting of a turbomolecular pump or the like, and this exhaust system 19 ensures that the inside of the chamber 11 is vacuumed to a predetermined level (for example, 10%). -1 ~10 -4 The exhaust is released up to Pa.

[0029] The sputtering source 13 consists of a target 131, an anode 132, and a magnet unit 133, with the target 131 connected as a cathode to a pulse power supply 16 for the sputtering source. Ar gas is supplied into the cluster growth cell 12 from the first inert gas supply pipe 17, and pulsed power is supplied from the pulse power supply 16 for the sputtering source, causing a glow discharge between the target 131 and the anode 132. In other words, a high voltage is applied in a pulsed manner between the target 131 and the anode 132, causing a glow discharge between the target 131 and the anode 132. Furthermore, by applying a magnetic field near the surface of the target 131 with the magnet unit 133, the cluster generation apparatus 10 of this embodiment can perform magnetron sputtering and generate an even stronger glow discharge.

[0030] The tip of the first inert gas supply pipe 17 is configured to inject the first inert gas from one or more locations between the target 131 and the anode 132 of the sputter source 13. However, the configuration is not limited to this, and any configuration can be adopted as long as the first inert gas can be supplied toward the target 131. The sputtering source 13 is housed within the cluster growth cell 12 so as to be movable in the axial direction of the tube. This defines the extension distance of the cluster growth region in the axial direction of the tube. The extension distance in the axial direction of the tube refers to the length of the growth region, i.e., the distance from the target 131 surface to the beam outlet 121.

[0031] To generate clusters, a second inert gas cooled to liquid nitrogen temperature is introduced into the cluster growth cell 12, while the first inert gas is supplied to the sputtering source 13 and pulsed power is supplied from the sputtering source pulse power supply 16. When pulsed power is supplied, sputtered particles such as neutral atoms and ions originating from the target 131 are released collectively into the second inert gas from the target 131.

[0032] This cluster is emitted at intervals corresponding to the repetition frequency of the pulse power applied to the sputtering source 13 and moves along the flow of the second inert gas. At this time, the sputtered particles, such as neutral atoms and ions that make up the cluster, combine with each other in the second inert gas to form clusters of various sizes. The generated clusters pass through the beam outlet 121 of the cluster growth cell 12 and then enter the subsequent ion detection device, etc.

[0033] The ion detection device 20 has an ion guide electrode 21 located near the beam outlet 121 of the cluster growth cell 12, thereby guiding the cluster ions emitted from the beam outlet 121 of the cluster growth cell 12. As shown in Figure 1, the ion detection device 20 includes a quadrupole ion deflector 22 provided on the beam outlet side of the ion guide electrode 21. The quadrupole ion deflector 22 deflects and extracts only one of the positive or negative ions within the cluster.

[0034] The ion detection device 20 has a quadrupole mass spectrometer 23 that analyzes the mass of the extracted clusters, and it can isolate only clusters of a specific mass and measure their generation amount using an ion detector 24 (picoammeter) that can apply a bias. For example, a current of 100 pA measured by the ion detector 24 corresponds to a cluster amount of 0.6 × 10⁻⁶ 9 This corresponds to particles / second (=1 fmol / second). By placing a support on top of the ion detector 24, only clusters of a specific mass can be deposited on the support.

[0035] 3. Effects of this embodiment Since the carrier body of this embodiment can be manufactured relatively easily, it can be mass-produced industrially. The method for manufacturing the support in this embodiment is simpler than conventional methods using dendrimers and is suitable for industrial mass production. [Examples]

[0036] The following will provide a more detailed explanation using examples.

[0037] 1. Method for preparing and evaluating cluster carriers Cluster carriers were fabricated using the cluster carrier manufacturing apparatus 7 shown in Figure 1. In detail, clusters of an alloy containing Pt and Co were generated using the magnetron sputtering method with the cluster generation apparatus 10. The apparatus specifications and experimental parameters are as follows. Sputtering source: Angstrom Sciences ONYX-2 Pulse power supply: Zpulser AXIA-150 Target: Pt-Co alloy (2-inch diameter, 99.9% purity or higher) Ar gas flow rate: 40-200 sccm He gas flow rate: 60-400 sccm Growth cell pressure: 10-40 Pa Growth cell inner diameter: 110 mm Growth area length: 190-290mm Beam extraction diameter: 12 mm

[0038] The alloy clusters were sorted by specific charge states using a quadrupole ion deflector 22 and then sorted by size using a quadrupole mass spectrometer 23. The alloy cluster ions were then landed on a glassy carbon electrode (corresponding to the support in this invention). The electrode diameter was 5 mm. The glassy carbon electrode was polished on a buff using an alumina suspension (particle size 0.05 μm), cleaned with ultrasound in ultrapure water after polishing, and then quickly introduced into a vacuum chamber to support the alloy clusters. The amount of clusters supported was calculated from the current value measured by the ion detector 20. The mass activity (catalytic activity) of the clusters in the cluster support was evaluated using a rotating disk electrode (RDE).

[0039] 2. Evaluation Results Tables 1 and 2 show the results when alloy clusters are supported. Note that the amount of support (ng-Pt / cm³) 2) refers to the amount of Pt supported in the alloy on the support. The results in Tables 1 and 2 show that in all compositions, the mass activity significantly exceeded that of the standard catalyst (TEC10E50E: manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.), which had a mass activity of 300 A / g. This is presumed to be due to the increased specific surface area resulting from the reduction in cluster size. Furthermore, in all compositions, the cluster support can be manufactured using the magnetron sputtering method with the cluster support manufacturing apparatus 7, making it industrially more advantageous for mass production than when using dendrimers.

[0040] [Table 1]

[0041] [Table 2]

[0042] The examples described herein are for illustrative purposes only and should not be construed as limiting the present invention. Although the present invention has been described with examples of typical embodiments, the language used in the description and illustrations of the present invention should be understood as descriptive and illustrative, not limiting. As detailed herein, modifications are possible within the scope or essence of the present invention without departing in any way. While specific structures, materials, and examples have been referenced in this detailed description of the present invention, it is not intended to limit the present invention to the disclosures herein, but rather to encompass all functionally equivalent structures, methods, and uses within the scope of the appended claims.

[0043] This disclosure is not limited to the embodiments detailed above, and various modifications or changes are possible within the scope of the claims of this disclosure. [Industrial applicability]

[0044] The support material of this disclosure can be used in a wide range of applications across various technical fields. For example, one support material of this disclosure can be suitably used in fuel cell electrode catalysts, organic synthesis reaction catalysts, exhaust gas catalysts, and the like. Because the support material of this disclosure has high catalytic activity, the amount of Pt used can be reduced, and since it can be mass-produced, it offers significant cost reduction benefits and can be widely adopted. [Explanation of symbols]

[0045] 7. Manufacturing equipment for cluster carriers 10 ... Cluster generator 11... Chamber 12... Cluster growth cells 13... Spatter source 14…Liquid nitrogen jacket 15 ... control device 16... Pulse power supply for sputtering source 17 ...First inert gas supply pipe 18 ...Second inert gas supply pipe 19... Exhaust system 20 ... Ion detection device 21 ... Ion guide electrode 22...Quadrupole ion deflector 23...quadrupole mass spectrometer 24... Ion detector 121... Beam outlet 131...Target 132... Anode 133...Magnetic Unit

Claims

1. A support comprising a cluster of alloys containing Pt and Co supported on a carrier, The amount of Pt loaded is 1 × 10 －１４ ng / cm ２ The above 1 x 10 ５ ng / cm ２ The following: A carrier having a mass activity (oxygen reduction current density per gram of Pt) for oxygen reduction reactions (ORR) of 500 A / g or more and 2 × 10⁴ A / g or less.

2. The carrier is made of a conductive material, as described in claim 1.

3. The composition of the cluster is Pt ４ Co ２ , Pt ５ Co, Pt ６ Co ２ , and Pt ７ Co ２ The carrier according to claim 1 or 2, which is one or more selected from the group consisting of

4. A manufacturing method for producing the carrier described in claim 1, The generation step for generating the aforementioned cluster, A supporting step of landing and supporting the cluster on the carrier, A method for manufacturing a carrier, comprising the following:

5. The system includes a selection step for selecting specific mass clusters having a specific mass range from among the aforementioned clusters. The method for manufacturing a carrier according to claim 4, wherein the loading step involves landing the specific mass cluster onto the carrier.

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