JP2009217975A - Fuel electrode catalyst, membrane electrode assembly, and fuel cell - Google Patents
Fuel electrode catalyst, membrane electrode assembly, and fuel cell Download PDFInfo
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
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- Inert Electrodes (AREA)
Abstract
Description
本発明は、燃料極触媒、これを備えた膜電極接合体及び燃料電池に関する。 The present invention relates to a fuel electrode catalyst, a membrane electrode assembly including the same, and a fuel cell.
近年、水素エネルギーから電気エネルギーを取り出すことができる発電装置、例えば、水素燃料電池などの開発研究が活発になってきた。水素は水を分解することで得られ、地球上に無尽蔵に存在するばかりか、物質量当たりに含まれる化学エネルギー量が大きく、しかも、エネルギー源として利用するときに有害物質や地球温暖化ガスを発生しないという利点を有する。 In recent years, research and development on power generation devices that can extract electrical energy from hydrogen energy, such as hydrogen fuel cells, has become active. Hydrogen is obtained by decomposing water and is not only inexhaustible on the earth, but also contains a large amount of chemical energy per substance, and when used as an energy source, harmful substances and global warming gases are used. It has the advantage that it does not occur.
水素ガスの代わりに、メタノールを使用する燃料電池の研究も活発に行われている。液体燃料であるメタノールを使用する直接メタノール型燃料電池（ＤＭＦＣ：Ｄｉｒｅｃｔ Ｍｅｔｈａｎｏｌ Ｆｕｅｌ Ｃｅｌｌ）は、燃料の取り扱い易さに加え、安価な燃料ということで家庭用や産業用の比較的小出力規模の電源として適している。 Research on fuel cells using methanol instead of hydrogen gas is also actively conducted. Direct methanol fuel cells (DMFCs) that use methanol, which is a liquid fuel, have a relatively small output power source for household and industrial use because they are inexpensive fuels in addition to the ease of handling of fuels. Suitable as
メタノール−酸素燃料電池の理論出力電圧は、水素−酸素燃料電池とほぼ同じであり、２５℃において約１．２Ｖである。ＤＭＦＣは理論的体積エネルギー密度がリチウムイオン電池の約１０倍と高く、次世代の電池として期待されている。 The theoretical output voltage of the methanol-oxygen fuel cell is almost the same as that of the hydrogen-oxygen fuel cell, and is about 1.2 V at 25 ° C. DMFC has a theoretical volume energy density about 10 times higher than that of a lithium ion battery, and is expected as a next-generation battery.
ＤＭＦＣの中央にはプロトン導電膜があり、その両側に陽極及び陰極の触媒層が配置される。陰極にはメタノールと水、陽極には酸素が供給される。陰極触媒には白金ルテニウム（ＰｔＲｕ）、陽極触媒には白金（Ｐｔ）触媒が使用される。 In the center of the DMFC, there is a proton conductive film, and anode and cathode catalyst layers are arranged on both sides thereof. Methanol and water are supplied to the cathode, and oxygen is supplied to the anode. Platinum ruthenium (PtRu) is used for the cathode catalyst, and platinum (Pt) catalyst is used for the anode catalyst.
陰極における反応機構を以下に説明する。 The reaction mechanism at the cathode will be described below.
まず、式（１）に従い、メタノールの酸化過程でＣＯが生成してＰｔ触媒上に化学吸着する。これはＣＯによるＰｔ触媒被毒である。 First, according to the formula (1), CO is generated during the methanol oxidation process and chemisorbed on the Pt catalyst. This is Pt catalyst poisoning by CO.
一方、Ｒｕ上には水が吸着し、式（２）に従い水酸基を生成する。このＲｕに結合した水酸基が式（３）に従ってＰｔに化学吸着したＣＯをアタックし、ＣＯ２に酸化する。 On the other hand, water is adsorbed on Ru, and a hydroxyl group is generated according to the formula (2). The hydroxyl group bonded to Ru attacks CO chemisorbed on Pt according to the formula (3) and oxidizes it to CO 2 .
ＣＨ３ＯＨ＋Ｐｔ＝Ｐｔ−ＣＯ＋４Ｈ＋＋４ｅ− …式（１）
Ｒｕ＋Ｈ２Ｏ＝Ｒｕ−ＯＨ＋Ｈ＋＋ｅ− …式（２）
Ｐｔ−ＣＯ＋Ｒｕ−ＯＨ＝Ｐｔ＋Ｒｕ＋ＣＯ２＋Ｈ＋＋ｅ− …式（３）
Ｒｕにはメタノールを酸化する触媒作用は無く、ＲｕはＰｔの被毒を軽減する助触媒である。上記の反応機構から、Ｐｔ原子とＲｕ原子は互いに近接して存在することが理想的であり、Ｐｔ５０Ｒｕ５０の組成が最も高活性であることが知られている。
CH 3 OH + Pt = Pt- CO + 4H ++ 4e- ... formula (1)
Ru + H 2 O = Ru- OH + H ++ e- ... formula (2)
Pt-CO + Ru-OH = Pt + Ru + CO 2 + H ++ e- ... Equation (3)
Ru has no catalytic action to oxidize methanol, and Ru is a promoter that reduces Pt poisoning. From the above reaction mechanism, it is ideal that Pt atoms and Ru atoms exist close to each other, and it is known that the composition of Pt50Ru50 is the most active.
ＤＭＦＣの熱力学的発生電池電圧は、上述の通り、約１．２Ｖであるが、実際の電池では、この電圧は得られない。この主な原因は以下の２点である。 As described above, the DMFC thermodynamically generated battery voltage is about 1.2 V, but this voltage cannot be obtained in an actual battery. The main causes are the following two points.
第１に、メタノール酸化反応の活性化エネルギーがＰｔＲｕ触媒を使用してもまだ大きく、アノード分極が大きいことである。 First, the activation energy of the methanol oxidation reaction is still large even when the PtRu catalyst is used, and the anodic polarization is large.
第２に、メタノールがプロトン導電膜を透過してカソードに達し、カソードで直接酸化されることである。メタノールの透過はメタノールクロスオーバーと呼ばれ、大きな問題である。 Second, methanol passes through the proton conductive film and reaches the cathode, where it is directly oxidized at the cathode. The permeation of methanol is called methanol crossover and is a big problem.
また、燃料電池に使用されるＰｔは極めて高価な貴金属である。触媒に使用するＰｔは酸化状態にある化合物を最終的に還元して合成される。Ｐｔの供給源として最も安価な化合物は六塩化白金酸であり、試薬レベルでの価格は２００６年７月現在、約２７５０円／ｇである。この試薬から１ｇの金属Ｐｔ触媒を合成するために必要な試薬コストは約７３２０円である。ＤＭＦＣの電極触媒の使用量は両極とも５０ｇ／ｍ２前後であり、電池電圧０．４Ｖでの一般的出力密度は２００Ｗ／ｍ２である。このことから、携帯電話に必要な電力１Ｗを供給するために必要な触媒量は金属Ｐｔ換算で０．５ｇであり、その試薬コストは約３６６０円にのぼる。この様な高額コストではＤＭＦＣを搭載した携帯機器を普及させるのは困難である。 Further, Pt used for fuel cells is a very expensive noble metal. Pt used as a catalyst is synthesized by finally reducing a compound in an oxidized state. The cheapest compound as a source of Pt is hexachloroplatinic acid, and the price at the reagent level is about 2750 yen / g as of July 2006. The reagent cost required to synthesize 1 g of metal Pt catalyst from this reagent is about 7320 yen. The amount of electrode catalyst used in DMFC is around 50 g / m 2 for both electrodes, and the general power density at a battery voltage of 0.4 V is 200 W / m 2 . From this, the amount of catalyst necessary for supplying 1 W of electric power necessary for the mobile phone is 0.5 g in terms of metal Pt, and the reagent cost is about 3660 yen. With such a high cost, it is difficult to spread portable devices equipped with DMFC.
この様な状況下、２００４年、米国イリノイ大学から新しいタイプの燃料電池が報告された（非特許文献１）。それは直接ギ酸型燃料電池（ＤＦＡＦＣ：Ｄｉｒｅｃｔ Ｆｏｒｍｉｃ Ａｃｉｄ Ｆｕｅｌ Ｃｅｌｌ）で、陰極燃料にギ酸、陽極燃料に酸素を使用するタイプのものである。この燃料電池のメリットは触媒としてＰｄを選択すれば、ギ酸が酸化されて二酸化炭素に変化する際、メタノール酸化の場合と異なり、反応過程で一酸化炭素を生じないこと、及び、ギ酸がプロトン導電膜中を殆ど透過しない点である。ギ酸の酸化反応を式（４）に示す。 Under such circumstances, a new type of fuel cell was reported in 2004 by the University of Illinois (Non-Patent Document 1). It is a direct formic acid fuel cell (DFAFC) that uses formic acid as the cathode fuel and oxygen as the anode fuel. The merit of this fuel cell is that if Pd is selected as a catalyst, when formic acid is oxidized to carbon dioxide, carbon monoxide is not generated in the reaction process unlike methanol oxidation, and formic acid is proton conductive. The point is that it hardly penetrates the membrane. The formic acid oxidation reaction is shown in Formula (4).
ＨＣＯＯＨ＝ＣＯ２＋２Ｈ＋＋２ｅ− …式（４）
この反応はギ酸からの直接脱プロトン反応である。したがって、素反応過程で一酸化炭素（ＣＯ）を生成することがなく、触媒を被毒する問題が無い。また、ギ酸はアルコールと異なり有機酸であるため、水溶液中で電離してギ酸イオン（ＨＣＯＯ−）を生成する。ギ酸イオンは陰イオンであり、代表的プロトン導電膜であるデュポン（ＤｕＰｏｎｔ）社のナフィオン（Ｎａｆｉｏｎ、登録商標）膜中のスルフォン酸陰イオンとの間に静電的斥力が生じる。
HCOOH = CO2 + 2H ++ 2e− Formula (4)
This reaction is a direct deprotonation reaction from formic acid. Therefore, carbon monoxide (CO) is not generated in the elementary reaction process, and there is no problem of poisoning the catalyst. Further, since formic acid is an organic acid unlike alcohol, it is ionized in an aqueous solution to produce formate ion (HCOO-). The formate ion is an anion, and an electrostatic repulsive force is generated between the sulfonate anion in the Nafion (registered trademark) film of DuPont, which is a typical proton conductive film.
この斥力により、ギ酸イオンがプロトン導電膜中を透過し難く、クロスオーバー量がＤＭＦＣのメタノールに比較して極めて少ない。この特長から、ＤＦＡＦＣではパッシブ状態（燃料供給のためにポンプ等を一切使用しないタイプ）でＤＭＦＣの２倍以上の出力密度を達成している。 This repulsive force makes it difficult for formate ions to permeate through the proton conductive film, and the amount of crossover is extremely small compared to DMFC methanol. Because of this feature, DFAFC achieves a power density more than twice that of DMFC in a passive state (a type that does not use any pump for supplying fuel).
また、ＤＦＡＦＣの陰極触媒にはＰｄが使用される。２００６年７月現在、Ｐｄ地金の価格はＰｔ地金の価格の約１／４であり、触媒材料コストも大幅に低減できる。 Pd is used as the cathode catalyst for DFAFC. As of July 2006, the price of Pd ingot is about 1/4 of the price of Pt ingot, and the cost of catalyst material can be greatly reduced.
また、水素ガスや、メタノールを使用する燃料電池では、陽極触媒の耐久性向上が重要である。陽極触媒は、Ｈ＋が多数存在する液体にさらされるため、触媒を構成する原子の溶出が起きやすくなるためである。これに関連して耐久性向上に関する研究結果が報告された（非特許文献２）。より貴であるＡｕを微量加えることで、大幅な耐久性向上が報告されている。 Further, in a fuel cell using hydrogen gas or methanol, it is important to improve the durability of the anode catalyst. This is because the anode catalyst is exposed to a liquid in which a large number of H + is present, so that elution of atoms constituting the catalyst easily occurs. In relation to this, research results on durability improvement have been reported (Non-Patent Document 2). A significant improvement in durability has been reported by adding a trace amount of Au, which is noble.
ＤＦＡＦＣの陽極でも課題は同様であるが、陰極においてもＰｔより卑なＰｄを用いるために、耐久性向上が重要である。ただし、Ａｕには触媒活性がないため、Ａｕ添加時の耐久性向上効果とともに、陰極触媒の活性を向上する工夫が必要となる。 Although the problem is the same for the anode of DFAFC, the use of Pd, which is lower than Pt, is also important for the cathode, so that it is important to improve durability. However, since Au has no catalytic activity, it is necessary to devise a technique for improving the activity of the cathode catalyst as well as the durability improving effect when Au is added.
上述のように、ＤＦＡＦＣはＤＭＦＣに比べ、高出力密度であり、かつ、触媒材料コストも低いものの、燃料電池として普及させるためには、さらなる出力密度の向上及び低コスト化及び耐久性の向上が望まれる。 As described above, DFAFC has a higher output density and lower catalyst material cost than DMFC, but in order to spread as a fuel cell, further improvement in output density, lower cost and improved durability are required. desired.
本発明は、上記に鑑みなされたものであり、ＰｔＲｕを燃料極触媒に用いたものに比べて、より高出力密度かつ低コストかつ長寿命の燃料電池を提供することを目的とする。 The present invention has been made in view of the above, and an object of the present invention is to provide a fuel cell having a higher output density, a lower cost, and a longer life than those using PtRu as a fuel electrode catalyst.
本発明は、燃料極と酸素極とを備えた燃料電池に供する燃料極触媒であって、ＰｄとＡｕとＮｉの三元系微粒子からなる。ＰｄとＡｕとＮｉの三元系微粒子は、Ｐｄ、Ａｕ、Ｎｉの三種の金属を主要な成分として含有する粒子である。三元系微粒子は、１〜８０ａｔ．％のＮｉを含有し、Ｐｄに対して０．１〜１０ａｔ．％のＡｕを含有し、残部がＰｄからなることを特徴とする。 The present invention is a fuel electrode catalyst for use in a fuel cell having a fuel electrode and an oxygen electrode, and is composed of ternary fine particles of Pd, Au, and Ni. The ternary fine particles of Pd, Au, and Ni are particles containing three kinds of metals of Pd, Au, and Ni as main components. Ternary fine particles are 1 to 80 at. % Ni, 0.1 to 10 at. % Au, and the balance is Pd.
また本発明は、燃料極触媒層と酸素極触媒層およびそれらの間に間挿された固体高分子電解質膜とからなる膜電極接合体であって、前記燃料極触媒層がＰｄとＡｕとＮｉの三元系微粒子からなり、１〜８０ａｔ．％のＮｉを含有し、Ｐｄに対して０．１〜１０ａｔ．％のＡｕを含有し、残部がＰｄからなることを特徴とする。 The present invention also provides a membrane electrode assembly comprising a fuel electrode catalyst layer, an oxygen electrode catalyst layer, and a solid polymer electrolyte membrane interposed therebetween, wherein the fuel electrode catalyst layer comprises Pd, Au, and Ni. 1 to 80 at. % Ni, 0.1 to 10 at. % Au, and the balance is Pd.
さらに本発明は、燃料極触媒層と酸素極触媒層との間に固体高分子電解質膜を有する膜電極接合体を備えた燃料電池であって、前記燃料極触媒層がＰｄとＡｕとＮｉの三元系微粒子からなり、１〜８０ａｔ．％のＮｉを含有し、Ｐｄに対して０．１〜１０ａｔ．％のＡｕを含有し、残部がＰｄからなることを特徴とする。 Furthermore, the present invention provides a fuel cell comprising a membrane electrode assembly having a solid polymer electrolyte membrane between a fuel electrode catalyst layer and an oxygen electrode catalyst layer, wherein the fuel electrode catalyst layer is made of Pd, Au and Ni. It consists of ternary fine particles, 1-80 at. % Ni, 0.1 to 10 at. % Au, and the balance is Pd.
燃料極触媒を上記の構成としたことにより、純Ｐｄ触媒よりも燃料の酸化活性が向上し、出力密度が向上するとともにＡｕの効果で耐食性が向上する。 Since the fuel electrode catalyst has the above structure, the oxidation activity of the fuel is improved as compared with the pure Pd catalyst, the power density is improved, and the corrosion resistance is improved by the effect of Au.
Ｐｄ−Ａｕ−Ｎｉ三元系微粒子は導電性カーボンに担持させることが望ましく、これにより、触媒を超微粒子化でき、その結果、出力密度が向上するとともにＡｕの効果で耐食性が向上する。 The Pd—Au—Ni ternary fine particles are desirably supported on conductive carbon, whereby the catalyst can be made into ultra fine particles. As a result, the output density is improved and the corrosion resistance is improved by the effect of Au.
本発明の燃料電池もしくは膜電極接合体において、酸素極触媒はＰｔとＰの二元系微粒子からなり、１〜５０ａｔ．％のＰを含有し、残部がＰｔからなるものとすることが好ましい。また、ＰｔとＰの二元系微粒子は導電性カーボンに担持させることが望ましい。これらにより、燃料電池全体としての出力密度をさらに向上させることができる。 In the fuel cell or membrane electrode assembly of the present invention, the oxygen electrode catalyst is composed of binary fine particles of Pt and P, and has a concentration of 1 to 50 at. % P is preferably contained, with the balance being Pt. Further, it is desirable that the Pt and P binary fine particles are supported on conductive carbon. As a result, the output density of the fuel cell as a whole can be further improved.
本発明の燃料電池において、燃料極の燃料はカルボキシル基を有する有機酸であることが好ましく、特にカルボキシル基を有する有機酸がギ酸であるものが好ましい。 In the fuel cell of the present invention, the fuel at the fuel electrode is preferably an organic acid having a carboxyl group, and particularly preferably the organic acid having a carboxyl group is formic acid.
本発明によれば、より高出力密度かつ低コストかつ長寿命の燃料電池を提供することができる。 According to the present invention, a fuel cell with higher power density, lower cost, and longer life can be provided.
発明者らは、密度汎関数理論を用いた第一原理的分子軌道計算法により、燃料極触媒として、純Ｐｄに代わり、ＰｄにＮｉとＡｕを添加したＰｄＡｕＮｉ触媒を用いることで、カルボキシル基を有するギ酸の酸化活性が高まることを見出した。Ａｕの効果で耐食性も向上する。 The inventors of the present invention have used a first-principles molecular orbital calculation method using density functional theory to replace a PdAuNi catalyst in which Ni and Au are added to Pd, instead of pure Pd, as a fuel electrode catalyst. It has been found that the oxidation activity of formic acid is increased. Corrosion resistance is also improved by the effect of Au.
Ｐｄと同じく水素吸蔵能力の高いＮｉをＰｄに添加すると、その相乗効果によりギ酸からの脱プロトン反応が促進され、ギ酸の酸化活性が向上するものと推察される。この点について、以下に詳細に説明する。 When Ni, which has a high hydrogen storage capacity like Pd, is added to Pd, it is presumed that the deprotonation reaction from formic acid is promoted by its synergistic effect, and the oxidation activity of formic acid is improved. This point will be described in detail below.
触媒表面での燃料の酸化分解反応については、密度汎関数理論を用いた第一原理的分子軌道計算法によって、各素反応を調べることができる。本発明で用いた手法及び解析例は、非特許文献３及び４に示されている。
Regarding the oxidative decomposition reaction of the fuel on the catalyst surface, each elementary reaction can be examined by the first principle molecular orbital calculation method using density functional theory.
Ｐｄ（１１１）面上のギ酸の分解反応を調べると、次の一連の素反応経路が主たるものと判明した。 When the decomposition reaction of formic acid on the Pd (111) surface was examined, it was found that the following series of elementary reaction pathways were the main ones.
ＨＣＯＯＨ→ＨＣＯＯ＋ｅ−＋Ｈ＋ …式（５）
ＨＣＯＯ →ＯＣＯ＋ｅ−＋Ｈ＋ …式（６）
ＯＣＯ →ＣＯ２↑ …式（７）
分解したＨは電解質膜へと拡散し、ＣＯ２が気化することになる。ＨＣＯＯの吸着構造は、２つのＯ原子がＰｄ（１１１）面の２つのＰｄ原子の直上に吸着する形をとり、ギ酸からＨ１原子が脱離した分解物の中で最も安定な吸着構造であることが判った。また、このために、反応式は式（５）−式（７）が主たる反応経路になることが判った。これらの一連の素反応における律速反応は式（６）であり、１．０ｅＶの活性化エネルギーが必要と判明した。Ｈは、ＣやＯに比べて高速振動しており、零点振動エネルギーが大きいので、脱離反応を起こしやすい。これが直接ギ酸型燃料電池の出力が高い理由であると理解できる。
HCOOH → HCOO + e− + H + (5)
HCOO-> OCO + e- + H + ... Formula (6)
OCO → CO2 ↑ ... Formula (7)
The decomposed H diffuses into the electrolyte membrane, and CO 2 is vaporized. The adsorption structure of HCOO is the most stable adsorption structure among the decomposition products in which two O atoms are adsorbed immediately above two Pd atoms on the Pd (111) plane, and H1 atoms are desorbed from formic acid. I found out. For this reason, it has been found that the reaction formulas are mainly the reaction pathways of the formulas (5) to (7). The rate-limiting reaction in these series of elementary reactions is the formula (6), and it was found that an activation energy of 1.0 eV is necessary. H vibrates at a higher speed than C and O, and has a large zero-point vibration energy, and thus easily causes a desorption reaction. This can be understood as the reason why the output of the direct formic acid fuel cell is high.
本解析には、ＰｄＡｕＮｉ触媒の表面の一部を原子集団モデルとして取り出して用い、式（６）の反応について解析して活性化エネルギーを調べた。 In this analysis, a part of the surface of the PdAuNi catalyst was taken out and used as an atomic group model, and the reaction of Formula (6) was analyzed to examine the activation energy.
ＰｄＡｕＮｉ上の活性化エネルギーがＰｄ（１１１）面より小さければ、触媒活性が高いことを示す。同一の反応において活性化エネルギーが０．１ｅＶ低い場合、アーレニウスの式から３００Ｋ（２７℃）での反応速度の増加はｅｘｐ［０．１ｅＶ／ｋＴ］≒４８倍と見積もられる。従って、活性化エネルギー０．１ｅＶの差は十分大きいと考えることができる。 If the activation energy on PdAuNi is smaller than the Pd (111) plane, it indicates that the catalytic activity is high. When the activation energy is 0.1 eV lower in the same reaction, the increase in the reaction rate at 300 K (27 ° C.) is estimated as exp [0.1 eV / kT] ≈48 times from the Arrhenius equation. Therefore, it can be considered that the difference in activation energy of 0.1 eV is sufficiently large.
ＨＣＯＯの吸着位置の直近にＡｕが存在する場合を考えて、図１（ａ）にＨＣＯＯの吸着構造、図１（ｂ）に脱離反応の中間構造、図１（ｃ）にＨ脱離後の構造を解析した結果を示す。 Considering the case where Au is present in the immediate vicinity of the HCOO adsorption position, FIG. 1A shows the HCOO adsorption structure, FIG. 1B shows the intermediate structure of the desorption reaction, and FIG. The result of analyzing the structure of is shown.
脱離反応の中間構造は、Ｈ脱離反応方向にはエネルギー極大で、他の方向の原子変位にはエネルギー極小となる構造である。ＨＣＯＯの吸着構造から脱離反応の中間構造に変形するのに必要なエネルギーが活性化エネルギーΔＥであり、ＰｄＡｕＮｉ触媒では０．９ｅＶと算出された。また、中間構造からＨ脱離後の構造に至るとエネルギーが１．１ｅＶ低下した。 The intermediate structure of the elimination reaction is a structure having an energy maximum in the H elimination reaction direction and an energy minimum in the atomic displacement in the other direction. The energy required to transform from the HCOO adsorption structure to the intermediate structure of the elimination reaction was the activation energy ΔE, and 0.9 eV was calculated for the PdAuNi catalyst. Further, the energy decreased by 1.1 eV from the intermediate structure to the structure after H desorption.
ＨＣＯＯの吸着位置に対して、Ａｕの存在位置を変えた解析の結果を、図２（ａ）、図２（ｂ）、図２（ｃ）に中間構造図と活性化エネルギーΔＥで示す。いずれも活性化エネルギーが０．９ｅＶと算出された。これらの解析では、ＯとＡｕの吸着が弱いので、Ａｕの直上にＯが吸着しない構造を考慮した。この解析では、Ｐｄ３９Ａｕ１Ｎｉ１８を扱ったので、Ａｕは、全体に対して１／５８すなわち１．７ａｔ％、Ｐｄに対しては１／３８すなわち２．６ａｔ％含まれている。 The analysis results obtained by changing the position where Au is present relative to the position where HCOO is adsorbed are shown in FIG. 2 (a), FIG. 2 (b) and FIG. 2 (c) as intermediate structure diagrams and activation energy ΔE. In all cases, the activation energy was calculated to be 0.9 eV. In these analyses, since the adsorption of O and Au is weak, a structure in which O is not adsorbed immediately above Au is considered. In this analysis, since Pd39Au1Ni18 was handled, Au is contained in 1/58, that is, 1.7 at%, and Pd is contained in 1/38, that is, 2.6 at%.
比較として、Ｐｄ触媒の表面の一部を原子集団モデルとして取り出して用い、式（６）の反応について解析して活性化エネルギーを調べた。図３（ａ）にＨＣＯＯの吸着構造、図３（ｂ）に脱離反応の中間構造、図３（ｃ）にＨ脱離後の構造を解析した結果を示す。 As a comparison, a part of the surface of the Pd catalyst was taken out and used as an atomic group model, and the reaction of the formula (6) was analyzed and the activation energy was examined. FIG. 3 (a) shows the HCOO adsorption structure, FIG. 3 (b) shows the intermediate structure of the desorption reaction, and FIG. 3 (c) shows the result of analyzing the structure after H desorption.
脱離反応の中間構造は、Ｈ脱離反応方向にはエネルギー極大で、他の方向の原子変位にはエネルギー極小となる構造である。ＨＣＯＯの吸着構造から脱離反応の中間構造に変形するのに必要なエネルギーが活性化エネルギーΔＥであり、Ｐｄ触媒では１．０ｅＶであった。また、中間構造からＨ脱離後の構造に至るとエネルギーが１．１ｅＶ低下した。 The intermediate structure of the elimination reaction is a structure having an energy maximum in the H elimination reaction direction and an energy minimum in the atomic displacement in the other direction. The energy required to transform from the HCOO adsorption structure to the intermediate structure of the elimination reaction was the activation energy ΔE, and 1.0 eV for the Pd catalyst. Further, the energy decreased by 1.1 eV from the intermediate structure to the structure after H desorption.
第２の比較として、ＰｄＮｉ触媒の表面の一部を原子集団モデルとして取り出して用い、式（６）の反応について解析して活性化エネルギーを調べた。図４（ａ）にＨＣＯＯの吸着構造、図４（ｂ）に脱離反応の中間構造、図４（ｃ）にＨ脱離後の構造を解析した結果を示す。 As a second comparison, a part of the surface of the PdNi catalyst was extracted and used as an atomic group model, and the activation energy was examined by analyzing the reaction of the formula (6). FIG. 4 (a) shows the HCOO adsorption structure, FIG. 4 (b) shows the intermediate structure of the desorption reaction, and FIG. 4 (c) shows the result of analyzing the structure after H desorption.
脱離反応の中間構造は、Ｈ脱離反応方向にはエネルギー極大で、他の方向の原子変位にはエネルギー極小となる構造である。ＨＣＯＯの吸着構造から脱離反応の中間構造に変形するのに必要なエネルギーが活性化エネルギーΔＥであり、ＰｄＮｉ触媒では０．９ｅＶであった。また、中間構造からＨ脱離後の構造に至るとエネルギーが１．１ｅＶ低下した。 The intermediate structure of the elimination reaction is a structure having an energy maximum in the H elimination reaction direction and an energy minimum in the atomic displacement in the other direction. The energy required to transform from the adsorption structure of HCOO to the intermediate structure of the elimination reaction was the activation energy ΔE, and 0.9 eV for the PdNi catalyst. Further, the energy decreased by 1.1 eV from the intermediate structure to the structure after H desorption.
上記の３つの比較結果から、ＨＣＯＯの吸着構造から脱離反応の中間構造に変形するのに必要な活性化エネルギーΔＥは、ＰｄＡｕＮｉ触媒で０．９ｅＶ、Ｐｄ触媒で１．０ｅＶ、ＰｄＮｉ触媒で０．９ｅＶであり、ＰｄＡｕＮｉ触媒はＰｄ触媒より０．１ｅＶ活性化エネルギーが低く、ＰｄＮｉ触媒とは同等であることが示された。これは、ＰｄにＮｉとＡｕを添加したＰｄＡｕＮｉ触媒が、Ｐｄ触媒に比べてギ酸の酸化活性が高いこと示すものである。 From the above three comparison results, the activation energy ΔE required to transform from the adsorption structure of HCOO to the intermediate structure of the elimination reaction is 0.9 eV for the PdAuNi catalyst, 1.0 eV for the Pd catalyst, and 0 for the PdNi catalyst. The PdAuNi catalyst has a lower activation energy of 0.1 eV than the Pd catalyst, indicating that it is equivalent to the PdNi catalyst. This indicates that the PdAuNi catalyst in which Ni and Au are added to Pd has higher formic acid oxidation activity than the Pd catalyst.
第３の比較として、ＰｄＡｕＮｉ触媒の表面の一部を原子集団モデルとして取り出して用い、反応（６）について解析して活性化エネルギーを調べた。図５（ａ）にＨＣＯＯの吸着構造を示す。ＯがＡｕの直上に吸着しない構造であるが、ＨがＡｕに吸着する形の脱離反応の活性化エネルギーを調べた。図５（ｂ）に脱離反応の中間構造、図５（ｃ）にＨ脱離後の構造を解析した結果を示す。脱離反応の中間構造は、Ｈ脱離反応方向にはエネルギー極大で、他の方向の原子変位にはエネルギー極小となる構造である。ＨＣＯＯの吸着構造から脱離反応の中間構造に変形するのに必要なエネルギーが活性化エネルギーΔＥであり、ＰｄＮｉ触媒では１．３ｅＶであった。また、中間構造からＨ脱離後の構造に至るとエネルギーが１．４ｅＶ低下した。 As a third comparison, a part of the surface of the PdAuNi catalyst was taken out and used as an atomic group model, and the reaction (6) was analyzed and the activation energy was examined. FIG. 5A shows the adsorption structure of HCOO. The activation energy of the elimination reaction in which O is not adsorbed directly on Au but H is adsorbed on Au was examined. FIG. 5B shows the result of analyzing the intermediate structure of the elimination reaction, and FIG. 5C shows the result of analyzing the structure after H elimination. The intermediate structure of the elimination reaction is a structure having an energy maximum in the H elimination reaction direction and an energy minimum in the atomic displacement in the other direction. The energy required to transform from the adsorption structure of HCOO to the intermediate structure of the elimination reaction was the activation energy ΔE, and 1.3 eV for the PdNi catalyst. Further, the energy decreased by 1.4 eV from the intermediate structure to the structure after H desorption.
第３の比較で示したように、ＨがＡｕに吸着する形の脱離反応では、活性化エネルギーが、Ｐｄ触媒より０．３ｅＶ増加した。よって、ＨがＡｕに吸着する形の脱離反応は、極めて起こりにくくなる。この理由は、ＡｕのＨ吸着エネルギーがＰｄより劣るためであると考えられる。したがって、上記の解析に用いた原子集団モデルの最表面に、Ａｕが２個分散すると、活性が大幅に低下することが予想される。このため、Ａｕの比率は、Ｐｄに対して１０ａｔ．％以下と考えられる。 As shown in the third comparison, in the desorption reaction in which H is adsorbed to Au, the activation energy is increased by 0.3 eV from the Pd catalyst. Therefore, a desorption reaction in which H is adsorbed to Au is extremely difficult to occur. The reason for this is considered that the H adsorption energy of Au is inferior to Pd. Therefore, it is expected that when two Aus are dispersed on the outermost surface of the atomic group model used in the above analysis, the activity is greatly reduced. Therefore, the Au ratio is 10 at. % Or less.
以下に、本発明の実施の形態について説明する。ただし、本発明は以下の実施の形態に限定される訳ではない。また、説明を明確にするため、以下の記載及び図面は、適宜、省略及び簡略化されている。 Embodiments of the present invention will be described below. However, the present invention is not limited to the following embodiments. Further, in order to clarify the explanation, the following description and drawings are appropriately omitted and simplified.
図６に本発明に係る燃料電池の代表的な構成例を示す。本実施例の燃料電池４０は固体高分子電解質膜４１、空気導入孔４２、酸素極側拡散層４３、酸素極側集電体４４、酸素極触媒層４５、燃料極触媒層４６、燃料極側集電体４７、燃料極側拡散層４８、燃料導入孔４９を備える。ここで、固体高分子電解質膜４１、酸素極触媒層４５および燃料極触媒層４６が、膜電極接合体を構成する。
FIG. 6 shows a typical configuration example of the fuel cell according to the present invention. The
固体高分子電解質膜４１は、燃料極で発生したプロトンを酸素極側に輸送する機能と、燃料極と酸素極の短絡を防止するセパレータとしての機能とを備えるものである。具体的には、デュポン社製のナフィオン１１２を用いることができる。
The solid
酸素極側集電体４４は、空気導入孔４２を介して空気（酸素）を取り込む構造体としての機能と集電機能とを有している。陽極燃料としては、大気中の酸素を用いることができる。酸素極側集電体４４から取り込まれた酸素は、酸素極側拡散層４３を介して酸素極触媒層４５に導かれる。この酸素極触媒層４５において、燃料極で生成された電子により還元され、同時に、燃料極で生成されたプロトンと反応して水を生成する。
The oxygen electrode side
酸素極触媒層４５に用いる酸素極触媒としては、Ｐｔ又はＰｔＰ触媒が好ましい。ＰｔにＰを添加すると、Ｐｔ触媒粒子がカーボン担体上に析出する際、Ｐが粒子の内部及び外部から作用し、析出するＰｔ触媒粒子を微細化して触媒の比表面積を増大させ、酸素還元活性が向上する。ＰｔＰ酸素極触媒を併用すれば燃料電池特性を一層高めることができる。この場合、Ｐの含有量は１〜５０ａｔ．％であることが好ましい。Ｐ含有量が１ａｔ．％未満ではＰｔ触媒の粒径を十分に微細化させることができず、触媒活性を十分に高めることができない。一方、Ｐ含有量が５０ａｔ．％超の場合、Ｐｔの含有量が低くなり触媒活性が低下する。
The oxygen electrode catalyst used for the oxygen
燃料極側集電体４７は、燃料導入孔４９を介して燃料を取り込む構造体としての機能と集電機能とを有している。陰極燃料としては、カルボキシル基を有する有機酸を用いることができ、特にギ酸が好ましい。具体的には、濃度１０ｍｏｌ／ｌ程度のギ酸が好ましい。燃料極側集電体４７から供給される燃料は燃料極側拡散層４８を介して燃料極触媒層４６に導かれる。この燃料極触媒層４６において、燃料が酸化され、電子とプロトンを放出する。この電子とプロトンは固体高分子電解質膜４１を介して酸素極側に移動する。上記の燃料の酸化反応及び酸素の還元反応により発電が起こる。
The fuel electrode side
燃料極触媒層４６に用いる本発明に係る燃料電池用燃料極触媒は、カーボン担体上に担持された一般式ＰｄＡｕＮｉで示される三元系微粒子からなる。Ｎｉの含有量は１〜８０ａｔ．％であることが好ましい。Ｎｉ含有量が１ａｔ．％未満ではＰｄ触媒の活性が十分高まらない。一方、Ｎｉ含有量が８０ａｔ．％超の場合、Ｐｄの含有量が低くなり触媒活性が低下する。Ａｕの含有量はＰｄに対して０．１〜１０ａｔ％であることが好ましい。Ｐｄに対してＡｕの含有量が０．１ａｔ．％未満ではＰｄ触媒の耐酸耐食性が十分高まらない。一方、Ｐｄに対してＡｕの含有量が１０ａｔ．％超の場合、Ａｕの低活性の影響が強くなり触媒活性が低下する。
The fuel electrode fuel electrode catalyst according to the present invention used for the fuel
また、ＰｄＡｕＮｉ触媒の粒径は２０ｎｍ以下が好ましい。触媒粒径が２０ｎｍより大きい場合には、触媒の比表面積が減少し、十分な触媒活性を得ることができない。粒径の下限は特に限定されないが、１ｎｍ未満では、触媒の電気化学的溶解が顕著となり、触媒の長期間耐久性に問題が生じる。同様の理由により、ＰｔＰ触媒の粒径も２０ｎｍ以下が好ましい。 The particle size of the PdAuNi catalyst is preferably 20 nm or less. When the catalyst particle size is larger than 20 nm, the specific surface area of the catalyst is reduced, and sufficient catalyst activity cannot be obtained. The lower limit of the particle size is not particularly limited, but if it is less than 1 nm, the electrochemical dissolution of the catalyst becomes significant, causing a problem in the long-term durability of the catalyst. For the same reason, the particle size of the PtP catalyst is preferably 20 nm or less.
本発明において、触媒担体としては、比表面積が２０〜８００ｍ２／ｇの導電性カーボンを用いることが好ましく、２０〜３００ｍ２／ｇの導電性カーボンを用いることがさらに好ましい。この比表面積の範囲ではカーボン担体の多孔性が低く、カーボン担体中に存在する微細孔が少ない。 In the present invention, as the catalyst carrier, the specific surface area is preferable to use a conductive carbon 20~800m 2 / g, it is more preferable to use a conductive carbon 20 to 300 m 2 / g. In this specific surface area range, the porosity of the carbon support is low, and there are few micropores present in the carbon support.
また、アセチレンブラック（ＡＢ）やマルチウォールカーボンナノチューブ（ＭＷＣＮＴ）等は全く微細孔を有さない非多孔質カーボン担体である。低多孔質或いは非多孔質カーボン担体を使用すれば、担体に存在する微細孔中に埋没する触媒粒子が減少し、より多くの触媒粒子をカーボン担体表面に析出させることができる。触媒粒子がカーボン担体表面に存在すれば、燃料とプロトン導電性高分子とが接触する確率が高まり、触媒利用率を向上させることができ、好ましい。 Acetylene black (AB), multi-wall carbon nanotubes (MWCNT), etc. are non-porous carbon carriers having no micropores. If a low porous or non-porous carbon support is used, the catalyst particles buried in the micropores existing in the support are reduced, and more catalyst particles can be deposited on the carbon support surface. If the catalyst particles are present on the surface of the carbon support, the probability that the fuel and the proton conductive polymer come into contact with each other increases, and the catalyst utilization rate can be improved.
特に、ＭＷＣＮＴは従来使用されてきたカーボンブラックに比べて低密度である。このため、触媒をナフィオン樹脂でペースト化し、プレス機により電極触媒膜にした場合、従来のカーボンブラック担体に比較して電極触媒膜中に物理的な空隙が多く存在する。よって、触媒上への燃料の拡散が十分確保される。また、酸素極触媒上で生成した水の拡散性が向上し、生成水が迅速に電極触媒膜表面に移動でき、電池特性が向上する。さらに、ＭＷＣＮＴは従来使用されてきたカーボンブラックに比較して比抵抗が低い。このためＩＲ損失を抑え、電池電圧の低下を抑制でき、好ましい。 In particular, MWCNT has a lower density than the conventionally used carbon black. For this reason, when the catalyst is pasted with Nafion resin and is made into an electrode catalyst film by a press machine, there are more physical voids in the electrode catalyst film than in the conventional carbon black support. Thus, sufficient fuel diffusion on the catalyst is ensured. Moreover, the diffusibility of the water produced | generated on the oxygen electrode catalyst improves, and produced water can move to the electrode catalyst membrane surface rapidly, and a battery characteristic improves. Furthermore, MWCNT has a lower specific resistance than carbon black that has been conventionally used. For this reason, IR loss can be suppressed and a decrease in battery voltage can be suppressed, which is preferable.
次に、本発明に係る触媒の製造方法について説明する。 Next, the method for producing the catalyst according to the present invention will be described.
燃料極触媒であるＰｄＡｕＮｉ触媒を合成する手法としては、例えば、アルコール還元法、超音波還元法、電子線照射還元法、放射線照射還元法、含浸法等が使用できるが、これらの手法に限定されるものではない。 As a method for synthesizing a PdAuNi catalyst that is a fuel electrode catalyst, for example, an alcohol reduction method, an ultrasonic reduction method, an electron beam irradiation reduction method, a radiation irradiation reduction method, an impregnation method, and the like can be used. It is not something.
Ｐｄ供給源としては、例えば、酢酸パラジウム（ＩＩ）、アセチルアセトナトパラジウム（ＩＩ）、塩化パラジウム（ＩＩ）ナトリウム、硝酸パラジウム（ＩＩ）、硫酸パラジウム（ＩＩ）などが使用できる。これらのパラジウム化合物を単独で使用しても、或いは２種類以上を併用してもよい。 As the Pd supply source, for example, palladium (II) acetate, acetylacetonato palladium (II), sodium palladium (II) chloride, palladium (II) nitrate, palladium (II) sulfate and the like can be used. These palladium compounds may be used alone or in combination of two or more.
また、燃料電池に使用される代表的プロトン導電膜であるデュポン社のナフィオン膜はパーフルオロアルキルスルフォン酸であり、極めて強い酸性を示す。したがって、Ｆｅ、ＣｏおよびＮｉ等の遷移金属はイオン化して溶解する。溶解した遷移金属イオンはナフィオン膜中のプロトンとイオン交換してプロトン導電性が低下し、電池特性を劣化させる原因となる。本発明のＰｄＡｕＮｉ触媒においても、この溶解現象が問題となる。 Further, a DuPont Nafion membrane, which is a typical proton conductive membrane used in a fuel cell, is perfluoroalkylsulfonic acid and exhibits extremely strong acidity. Therefore, transition metals such as Fe, Co, and Ni are ionized and dissolved. The dissolved transition metal ions are ion-exchanged with protons in the Nafion membrane, resulting in a decrease in proton conductivity, which causes deterioration of battery characteristics. This dissolution phenomenon also becomes a problem in the PdAuNi catalyst of the present invention.
この問題を解決する手段として、触媒合成後、硫酸、硝酸および塩酸等の酸中で触媒を浸漬処理し、ＰｄＡｕＮｉ触媒表面に存在するＮｉを除去することが有効である。 As a means for solving this problem, it is effective to remove Ni present on the surface of the PdAuNi catalyst by immersing the catalyst in an acid such as sulfuric acid, nitric acid and hydrochloric acid after the synthesis of the catalyst.
具体的には、例えば、以下の方法により、本発明に係るカーボン担持ＰｄＡｕＮｉ触媒を得ることができる。 Specifically, for example, the carbon-supported PdAuNi catalyst according to the present invention can be obtained by the following method.
アセチルアセトナトパラジウム（ＩＩ）２．８２ｍｍｏｌとアセチルアセトナト金（Ｉ）０．０５ｍｍｏｌと硝酸ニッケル・六水和物２．８２ｍｍｏｌをそれぞれ１００ｍｌのエチレングリコールに溶解させ、導電性カーボン（キャボット（Ｃａｂｏｔ）社製Ｖｕｌｃａｎ ＸＣ−７２Ｒ、比表面積２５４ｍ２／ｇ）０．５ｇを分散させた２００ｍｌのエチレングリコール溶液に加える。窒素ガス雰囲気下、２００℃で、この溶液を攪拌しながら４時間還流し、ＰｄＡｕＮｉ触媒を導電性カーボン上に析出担持させる。反応終了後、触媒を５０℃、１ｍｏｌ／ｌの硫酸水溶液中で７２時間浸漬攪拌し、触媒表面に存在するＮｉを溶解除去する。その後、触媒を濾別し、純水で洗浄後乾燥させて、本発明に係るカーボン担持ＰｄＡｕＮｉ触媒を得ることができる。また、硝酸ニッケル・六水和物に代え、同量のシュウ酸ニッケルを用いても良い。 2.82 mmol of acetylacetonatopalladium (II), 0.05 mmol of acetylacetonatogold (I) and 2.82 mmol of nickel nitrate hexahydrate were dissolved in 100 ml of ethylene glycol, respectively, to form conductive carbon (Cabot). (Vulcan XC-72R, specific surface area 254 m 2 / g) manufactured by the company is added to 200 ml ethylene glycol solution in which 0.5 g is dispersed. The solution is refluxed for 4 hours with stirring at 200 ° C. in a nitrogen gas atmosphere to deposit and support the PdAuNi catalyst on the conductive carbon. After completion of the reaction, the catalyst is immersed and stirred in a 1 mol / l sulfuric acid aqueous solution at 50 ° C. for 72 hours to dissolve and remove Ni present on the catalyst surface. Thereafter, the catalyst is filtered off, washed with pure water and then dried to obtain the carbon-supported PdAuNi catalyst according to the present invention. In place of nickel nitrate hexahydrate, the same amount of nickel oxalate may be used.
酸素極用に用いるＰｔＰ触媒の製造方法について説明する。 A method for producing a PtP catalyst used for the oxygen electrode will be described.
使用するＰ含有化合物としては、亜燐酸、亜燐酸塩（正塩及び酸性塩の両方を含む）、次亜燐酸、次亜燐酸塩が好ましい。塩としてはアルカリ金属塩（例えば、亜燐酸ナトリウム、亜燐酸水素ナトリウム、次亜燐酸ナトリウム等）又はアンモニウム塩（亜燐酸アンモニウム、亜燐酸水素アンモニウム、次亜燐酸アンモニウム等）が好ましい。燐酸や燐酸塩中のＰの酸化数は＋５価である。＋５価の酸化数はＰの最高酸化数であり、その電子配置はＮｅと同じ希ガス電子配置である。このため、燐酸や燐酸塩中のＰ原子は化学的に安定化してＰ供給源とならないため、適さない。ＰｔＰ触媒の合成には、酸化数＋５未満のＰを含有する化合物を使用しなければならない。 P-containing compounds to be used are preferably phosphorous acid, phosphites (including both normal salts and acidic salts), hypophosphorous acid, and hypophosphites. The salt is preferably an alkali metal salt (for example, sodium phosphite, sodium hydrogen phosphite, sodium hypophosphite, etc.) or an ammonium salt (ammonium phosphite, ammonium hydrogen phosphite, ammonium hypophosphite, etc.). The oxidation number of P in phosphoric acid or phosphate is +5. The + 5-valent oxidation number is the highest oxidation number of P, and the electron arrangement is the same noble gas electron arrangement as Ne. For this reason, P atoms in phosphoric acid and phosphates are not suitable because they are chemically stabilized and do not serve as a P supply source. For the synthesis of PtP catalysts, compounds containing P with an oxidation number of less than +5 must be used.
具体的には、例えば、ビス（アセチルアセトナト）白金（ＩＩ）２．５６ｍｍｏｌと次亜燐酸ナトリウム１．２８ｍｍｏｌをそれぞれ１００ｍｌのエチレングリコールに溶解させ、導電性カーボン（キャボット社製Ｖｕｌｃａｎ ＸＣ−７２Ｒ、比表面積２５４ｍ２／ｇ）０．５ｇを分散させた２００ｍｌのエチレングリコール溶液に加える。窒素ガス雰囲気下、２００℃で、この溶液を攪拌しながら４時間還流し、ＰｔＰ触媒を導電性カーボン上に析出担持させる。反応終了後、濾過、洗浄、乾燥させ、カーボン担持ＰｔＰ触媒を得ることができる。 Specifically, for example, 2.56 mmol of bis (acetylacetonato) platinum (II) and 1.28 mmol of sodium hypophosphite are dissolved in 100 ml of ethylene glycol, respectively, and conductive carbon (Vulcan XC-72R manufactured by Cabot Corporation, Specific surface area 254 m 2 / g) is added to 200 ml ethylene glycol solution in which 0.5 g is dispersed. The solution is refluxed for 4 hours with stirring at 200 ° C. in a nitrogen gas atmosphere to deposit and support the PtP catalyst on the conductive carbon. After completion of the reaction, the carbon-supported PtP catalyst can be obtained by filtration, washing and drying.
４０…燃料電池、４１…固体高分子電解質膜、４２…空気導入孔、４３…酸素極側拡散層、４４…酸素極側集電体、４５…酸素極触媒層、４６…燃料極触媒層、４７…燃料極側集電体、４８…燃料極側拡散層、４９…燃料導入孔。
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011253627A (en) * | 2010-05-31 | 2011-12-15 | National Institute For Materials Science | Electrode catalyst for fuel cell and manufacturing method thereof |
| JP2011253626A (en) * | 2010-05-31 | 2011-12-15 | National Institute For Materials Science | Electrode catalyst for fuel cell and manufacturing method thereof |
| CN103007964A (en) * | 2013-01-10 | 2013-04-03 | 太原理工大学 | Preparation method of carbon loaded hollow nanogold nickel alloy catalyst for direct methanol fuel cell |
| WO2013172050A1 (en) * | 2012-05-15 | 2013-11-21 | トヨタ自動車株式会社 | Method for producing catalyst for fuel cells, and fuel cell which comprises catalyst for fuel cells produced by said production method |
| DE112020005381T5 (en) | 2019-10-31 | 2022-08-11 | Jtekt Corporation | FUEL CELL SYSTEM |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2011253627A (en) * | 2010-05-31 | 2011-12-15 | National Institute For Materials Science | Electrode catalyst for fuel cell and manufacturing method thereof |
| JP2011253626A (en) * | 2010-05-31 | 2011-12-15 | National Institute For Materials Science | Electrode catalyst for fuel cell and manufacturing method thereof |
| WO2013172050A1 (en) * | 2012-05-15 | 2013-11-21 | トヨタ自動車株式会社 | Method for producing catalyst for fuel cells, and fuel cell which comprises catalyst for fuel cells produced by said production method |
| CN103007964A (en) * | 2013-01-10 | 2013-04-03 | 太原理工大学 | Preparation method of carbon loaded hollow nanogold nickel alloy catalyst for direct methanol fuel cell |
| DE112020005381T5 (en) | 2019-10-31 | 2022-08-11 | Jtekt Corporation | FUEL CELL SYSTEM |
| US11804610B2 (en) | 2019-10-31 | 2023-10-31 | Jtekt Corporation | Fuel cell system |
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