JP4235986B2 - Inert cathode for selective oxygen reduction and its preparation - Google Patents
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Description
本発明は、少なくとも１種の遷移金属及びカルコゲンからの半導性クラスターをベースとする選択的に作用する触媒物質製の薄い表面被覆を有する、メタノール−燃料電池中での多電子移動による電気化学的エネルギー変換のための、酸性媒体中の選択的酸素還元用不活性陰極及びその製法に関する。
放射なしの燃料電池技術を用いて、熱生産を介する迂回なしに電流を有効かつ環境認容性に得ることができる。燃料電池は、連続的に燃料−酸化反応の化学的エネルギー変化を電気エネルギーに変換する電気化学的電池である。この際、多電子トランスファーがこのエネルギー変換のための物理的基本を成す。陽極で、燃料分子が電子放出下に酸化され、陰極で電子の吸収下に酸化剤の還元が行われる。陽極及び陰極で形成されたイオンは、電解液中の閉電流回路で電極の方に移動して、そこで一緒になって水及び二酸化炭素を生じる。この場合に、電解質酸の使用は、汚染性炭酸塩形成に対して自然の保護を形成する。
技術水準
高いエネルギー密度を有する無害な燃料としての単純メタノールの使用は、８０〜１２０℃の低い温度範囲内での燃料電池の作動を可能とする。しかしながら、この際に起こるメタノール−クロスオーバーは問題がある。陰極用に従来最も頻繁に使用された触媒物質は、白金であり、これは、メタノールに比べても広い触媒反応可能性を有するが、白金電極の有毒化の危険をも有する。従って、かつ白金の場合の高い材料コストの故に、新しい選択的に作用する触媒物質が強く望まれている。ここで、カルコゲン原子のマトリックス中に包埋されている遷移金属の半導性のクラスター化合物に行き当たった。このいわゆる”シェブレル相構造”を有するクラスター化合物は、選択的作用を示し、即ち、これはメタノールを酸化も還元もせず、酸素のみを還元する。これにより、メタノールを陰極から遠ざけるための高価で、信頼性の低い膜の使用が省略できる。
ＤＥ ３６２４０５４Ａ１は、燃料電池中で酸素を還元して水にするための触媒作用を有する半導性モリブデンクラスターカルコゲニドからの不活性電極を記載している。この混合クラスタ−物質は、多結晶質であり、粉砕された粉末状態で、電極上の層厚を限定する１μｍ〜５μｍの間の粒径を有し、従って溶剤との混合の後に粗分散性の物質系が存在する。しかしながら、少ない液体量の施与及び引き続く溶剤の蒸発の後の電極表面上のクラスター分布は均一ではなく、このことはこの電極の選択的及び触媒作用的特性を悪化させることがありうる。
ＤＥ ３８０２２３６Ａ１からは、如何にして、反応すべき物質（金属カルボニル、カルコゲン含有化合物及び不活性有機溶剤）の混合物から熱の作用下に粉末又は薄層又は膜を製造することができ、燃料電池中の触媒作用を有する不活性電極を得るために使用できるかを知ることができる。この金属カルコゲニドも、多結晶質であり、溶剤中で粗分散性系をもたらす。これは、μｍ−範囲の直径を有する凝集されたクラスターを有し、これは、その大きさに基づき−ここに開示の、いずれにせよ高い物質使用量での噴霧熱分解析出の方法にもかかわらず−電極上の表面被覆中での均一な分布をもたらさず、場所的に異なる触媒作用及び選択作用を限定することがありうる。この際に、被覆の層厚は、クラスターの大きさにより下方に限定される。
このような触媒物質の製造はコストがかかり、１１００℃付近の高温範囲でのみ可能である。従って、類似の特性を有する物質を製造するために、他の方法が求められた。
本発明の出発点である技術水準は、前記の一般的詳述に基づき、O.Solorza-Feria等の論文”Novel Low-Temperature Synthesis of Semiconducting Transition Metal Chalcogenide Electrocatalyst for Multielectron Charge Transfer:Molecular Oxygen Reduction.,“Electrochimica Acta,Vol.39,No.11/12（1994）,pp.1647-1653から構成される。この論文から、式：
（Ｒｕ１−ｘＭＯｘ）ｙＳｅＯｚ（０．０２＜ｘ＜０．０４、１＜ｙ＜３、ｚ≒２ｙ）の半導性クラスター物質が、金属カルボニルＲｕ３（ＣＯ１２）及びＭｏ（ＣＯ）６及びセレンの混合物から、溶剤としてのキシレン中での湿式化学−有機低温合成により得ることができることが判る。生じた混合クラスターは、２種の遷移金属及び１種のカルコゲンをベースとしている。これらは、不活性陰極の表面被覆のために、粉末又は薄層（＜０．５μｍ）の形で提供することができる。この出現形でのクラスター物質は、白金と匹敵する酸性媒体中での酸素還元に関する電気触媒作用活性を有し、選択的に反応する。しかしながら、この際に、この特性は、被覆中の個々のクラスターの充填密度により限定され、この充填密度は、凝集されたクラスターを有する粉末としての又は狭い隣接クラスターを有する薄層としての出現形により限定され、このクラスターのその作用に逆方向の妨害をもたらしうる。
従って、本発明の基礎となっている問題は、酸性メタノール溶液中の酸素還元の選択性及び触媒反応を公知の出現形の物質に比べて更に改善する作用をする、選択的に作用する触媒物質からなるこのような表面被覆を有する不活性陰極を提供することである。
この目的は、本発明により、薄い表面被覆が、コロイド分散性の均一分布での個々のクラスターから有効陰極表面積１ｃｍ２当たりｎｇ−範囲の低い物質使用量により得られる被覆度を有することにより達成される。
個々のクラスターのこのような分布により、これは、逆に妨害することなしに、その完全な触媒作用及び選択的活性を発揮することができる。個々のクラスターのこの活性化は、高い作用密度を生ぜしめる。この場合に、触媒反応可能性は、なお前記の出現形での物質のそれを越える。本発明のコロイド分散性の、即ち、均一な出現像でのｎｍ−範囲（例えば３〜４ｎｍ）の粒径を有する個々のクラスターの非常に微細に分布された配置は、陰極を触媒毒及びこれに伴う活性の低下に対して有効に保護する。高価な膜は不必要である。酸素還元時のこの改善された選択性及びそれに伴う長時間安定性と一緒になって、例えば６〜７ｎｍのみの層厚が必要であるその薄い表面被覆を有する本発明の陰極は、従って、粉末又は薄層でのより厚い被覆に比べて利点を有する。更に、陰極表面の僅かな被覆度をもたらす個々のクラスターの広空間分布により、必要な物質使用量も相応して僅かであり、ｎｇ−範囲（例えば３．１ｎｇ）である。更に、この触媒物質は、非常に熱安定であるので、熱処理を実施することができる。
後の実施に先立ち、この位置で既に、本発明による陰極の前記の有利な特性は、それ自体、簡単に合成できるコロイド溶液としての触媒物質の出現形により可能になることが認められる。従って、電気触媒活性のための特別誂え生成物を提供することができる。
半導性遷移金属、殊にモリブデン（Ｍｏ）、タングステン（Ｗ）、ルチウム（Ｒｕ）、オスミウム（Ｏｓ）、コバルト（Ｃｏ）、ロジウム（Ｒｈ）及びイリジウム（Ｉｒ）並びにカルコゲン 硫黄（Ｓ）、セレン（Ｓｅ）、殊に赤色セレン及びテルル（Ｔｅ）がコロイド分散性クラスター分布を有する触媒物質の基礎となっている。これらの元素から、それぞれ、酸素（Ｏ）の関与下に二元クラスター及び三元混合クラスターを得ることができる。
本発明による不活性陰極の１態様によれば、遷移金属がルテニウム（Ｒｕ）であり、カルコゲンが硫黄（Ｓ）又はセレン（Ｓｅ）であり、このクラスターが、０．５〜２の範囲内のルテニウム（Ｒｕ）対カルコゲン（Ｓ、Ｓｅ）のモル比（ｘ）を有する際に、有利である。このようなクラスターは、電解質酸に対して特別な抵抗を有し、合成時に、硫黄及び赤色セレンの場合には８環−構造により、特別に製造好適な特性を提供する。
もう一つの本発明の態様によれば、遷移金属としてのルテニウム（Ｒｕ）及びカルコゲンとしてのセレン（Ｓｅ）を有するクラスターが化学量論的な形（Ｒｕ）ｎＳｅ（この際、ｎは１．５〜２、殊に１．７である）で存在する場合に特に好適である。触媒物質としてのこの化学量論的構造を有するクラスターは、高い触媒活性及び選択活性の要求を特別に優れて満足する。
本発明による陰極は、触媒的及び選択的に高活性の物質からなる薄い表面被覆により、化学的侵害に対して有効に保護されて、白金又は類似貴金属又は化合物を用いるる高価な陰極構造を必要としない。従って、この発明の遂行により、陰極が多孔性で導電性の支持体を有することができる。この多孔性は、この反応のための高い陰極比表面積に作用する。この支持体は、殊にカーボンブラック−又はノーリット−型−炭素からの適切な価格の基質であってよく、これは、燃料電池中のガス拡散電極中での使用のために特に好適である。ガス拡散電極は、１つの疎水性層及び１つの親水性層及びこの間の反応性固体層を有して３相に構成されている。慣用の基質、例えばガラス化された炭素−又はインジウム−錫−酸化物（ＩＴＯ）−基質の使用が同様に可能である。
アルカリ性電解質を有する燃料電池では、アルカリ溶液中で炭酸塩を生じさせる二酸化炭素による電解質の不純化が起こり得る。これにより、この電解質の導電性及び電極の寿命が低下する。従って、燃料電池を、酸性媒体を用いて、殊に本発明の１態様により、液状電解質として最も屡々使用される硫酸を用いて構成することが最も好適である。燐酸の使用も同様に可能であるが、これは高温（３００℃）でのみ導電性である。
直接メタノール−燃料電池は、大気圧又は過圧時に、かつ８０〜１００℃の操作温度で作動する。エネルギーの多いメタノールは、水素取得のために、リフォーマーターを介する迂回なしに直接分解される。従って、この発明のもう一つの態様では、このメタノール−燃料電池を直接燃料電池として構成する場合が好適である。
選択的酸素還元のための前記の不活性陰極を製造する方法は、本発明により、ｎｍ−範囲の薄い表面被覆を得るために、陰極の多孔性支持体を、コロイド溶液の形の触媒物質中に浸漬させ、引き続き室温で乾燥させ、その後、２００〜３００℃、殊に２０８℃の温度で熱処理することを特徴とする。このようなプロセスは、装置及び経費の点で多大のコストを要せずに実施可能であり、既に１回の処置で、最良の結果が得られる。コロイド状触媒物質中への浸漬により、陰極表面は一様に液状表面被覆を備える。殊に乾燥プロセスの促進のために真空中でも行われるこの被覆の乾燥の後に、このコロイドの固体成分は、コロイド分散性で均一な分布で支持体上に固定されている。なお存在する不純物は、次いで、熱処理工程で、この触媒物質を害することなしに、簡単に蒸発させることができる。
この場合に、発明のもう一つの態様によれば、コロイド溶液を、クラスターが、長鎖状安定剤の適当な量の添加下に、コロイド分散性の均一な分布で有機溶剤中に浮遊するように構成するのが有利であり、この際、安定剤の沸点（Ｔｓｓ）は溶剤の沸点（Ｔｓｌ）よりも上である。このようなコロイド溶液を用いて、必要なクラスター物質を特別誂眺えで提供することができる。溶剤は、支持体物質である。長鎖状安定剤は、クラスターへの積層によりそれが集塊して粉末になることを阻止する。その使用量は、溶剤中のクラスター起源に依存して、個々の成分のモル比を介して確かめることができる。この変換反応は、溶剤の沸点（Ｔｓｌ）では、殆ど使用成分に無関係に起こる。溶剤の沸点（Ｔｓｌ）よりも上である安定剤の沸点（Ｔｓｓ）の状態は、安定剤及びクラスターの微細分布に影響することなしに、溶剤の除去可能性を保証する。安定剤は熱処理工程で初めて除去されるので、陰極表面上にはなおコロイド分散性で均一に分布されたクラスターのみが存在し、堅固な被覆を形成する。
コロイド溶液の製造は、この発明の遂行時に、特に簡単かつ経済的に有利に溶剤の沸点（Ｔｓｌ）の範囲内で、湿式化学−有機合成により行うことができる。この製造法は、粉末形又は薄層形の公知触媒物質の製造法と同様に行なわれる。これは、溶剤中に１種以上の金属カルボニルを１種のカルコゲンと一緒に入れることに基づく。本発明では、なおこれに安定剤を加える。
金属カルボニルＭ（複数の金属カルボニルの組み合わせとしても）の多様性は、範囲が広く、殊に、
・Ｍ（ＣＯ）６（Ｍ＝Ｍｏ、Ｗ）
・Ｍ３（ＣＯ）１２（Ｍ＝Ｒｕ、Ｏｓ）
・Ｍ４（ＣＯ）１２（Ｍ＝Ｃｏ、Ｒｈ、Ｉｒ）
・Ｍ６（ＣＯ）１６（Ｍ＝Ｃｏ、Ｒｈ、Ｉｒ）
を含有する。
カルコゲンの多様性は、Ｘ＝Ｓｅ、Ｔｅ、Ｓを包含する。ここで、８−環−カルコゲン、例えば赤色セレン及び硫黄が、その純度により、合成のための特に良好な特性を惹起する。
有機溶剤としては、
・トルエン Ｃ６Ｈ５ＣＨ３ Ｔｓｌ＝１１１℃
・キシレン Ｃ６Ｈ４（ＣＨ３）２ Ｔｓｌ＝１３９℃／１４０℃
・メシチレン Ｃ６Ｈ３（ＣＨ３）３ Ｔｓｌ＝１６５℃
が好適である。
長鎖状安定剤の多様性は、同様に範囲が広い。殊に、
本発明によれば、溶剤が１４０℃の沸点（Ｔｓｌ）を有するキシレンであり、安定剤が１８５℃の沸点（Ｔｓｓ）を有する１−オクタデカンチオールである場合が特に有利である。遷移金属としてのルテニウム（Ｒｕ）及びカルコゲンとしてのセレン（Ｓｅ）を有するクラスターが化学量論的な形（Ｒｕ）ｎＳｅ（ここで、ｎは１．５〜２、殊に１．７である）で存在する、本発明による不活性陰極の前記の更なる実施形及び２０８℃の温度と関連して、優れた触媒的及び選択的特性を有する最適な陰極を得るために、全ての成分が加えられる。この際、そのコロイド分散性の分布に基づき、有効電極表面積１ｃｍ２当たり触媒物質約３．１ｎｇのみが必要となり、これは極めてコスト的に有利である。
次に、この触媒物質の合成を簡単に説明する：
還流冷却器を備えたフラスコ中で、溶剤キシレン（１００ｍｌ）を、成分と反応するはずの酸素を除去するためにアルゴンで１０分間フラッシングする。次いで、キシレン中に、紛状セレン（１８ｍｇ；２２．８μＭ）を１４０℃まで加熱することにより溶解させ、この溶液を再び室温まで冷却させる。これに半導性の遷移金属カルボニルであるトリルテニウムドデカ−カルボニル（Ｒｕ３（ＣＯ）１２；７２．９ｍｇ；１１．４μＭ）及び安定剤である１−オクタデカンチオール（２２０ｍｇ；７６．９μＭ）を加える。この際、安定剤の量は、モル比６．７５の際にカルボニル量の約３倍である。１４０℃のキシレン−沸点（Ｔｓｌ）までの約２０時間にわたる加熱の後に、クラスター形成が進行する。この反応の間にコロイドを常に撹拌し、還流冷却により冷却させる。
公知技術水準で公知であるようなクラスター形成の間の粉末又は薄層の沈着のための基質の供給は、このコロイドの製造の際には不必要である。収率は１００％、即ち、装入された物質の全てが反応される。例えば粉末形成時に公知であるようなフラスコ内面の沈着によるロスは生じない。
形成されたクラスターは、３ｎｍ〜４ｎｍの寸法を有する。ガラス化された炭素基質（Glassy Carbon GC）上の６ｎｍ〜７ｎｍの薄い層上で測定されるルーサーフォード・後方散乱法（ＲＢＳ）による化学量論的組成は、本発明の特に有利な実施形中に記載されているようなＲｕ１．７Ｓｅを生じる。
図面中に、０．５Ｍ硫酸中の、ガラス化された炭素製の熱処理された複数の同じ電極板（これらは、それぞれ触媒作用物質Ｒｕ１．７Ｓｅのコロイド溶液５μｌからの薄い層で被覆されている）の電気化学的酸素還元電流の負の経過を、電極電位（ＮＨＥ−標準水素電極、標準電極）と関連させて示す。ここで、曲線に沿った垂直線は、数回行った測定の僅かな誤差幅を表している。この経過は、メタノール１Ｍの添加の後には不変のまま残り、このことは、本発明による不活性陰極の高い選択性を示唆している。活性範囲は、この曲線の下部直線部分にあり、メタノールの使用時には白金のそれよりも良好であり、このことは、コロイド分散性コロイドから誘導された均一表面被覆を有する本発明による陰極の良好な触媒特性を立証している。The present invention relates to electrochemistry by multi-electron transfer in a methanol-fuel cell having a thin surface coating of a selectively working catalytic material based on semiconducting clusters from at least one transition metal and chalcogen. TECHNICAL FIELD The present invention relates to an inert cathode for selective oxygen reduction in an acidic medium and a method for producing the same for efficient energy conversion.
Using radiation-free fuel cell technology, current can be obtained effectively and environmentally acceptable without bypassing through heat production. A fuel cell is an electrochemical cell that continuously converts the chemical energy change of a fuel-oxidation reaction into electrical energy. In this case, multi-electron transfer forms the physical basis for this energy conversion. At the anode, the fuel molecules are oxidized under electron emission, and the oxidant is reduced at the cathode under electron absorption. Ions formed at the anode and cathode move toward the electrodes in a closed current circuit in the electrolyte, where they together produce water and carbon dioxide. In this case, the use of electrolyte acids forms a natural protection against fouling carbonate formation.
The use of simple methanol as a harmless fuel having a high energy density in the state of the art allows the fuel cell to operate within a low temperature range of 80-120 ° C. However, the methanol-crossover that occurs at this time is problematic. The catalyst material most frequently used in the past for the cathode is platinum, which has a wider catalytic reaction potential than methanol, but also has the risk of poisoning the platinum electrode. Thus, and because of the high material costs in the case of platinum, new selectively acting catalytic materials are highly desirable. Here, we encountered a semiconducting cluster compound of a transition metal embedded in a matrix of chalcogen atoms. The cluster compound having this so-called “chevrel phase structure” exhibits a selective action, ie it does not oxidize or reduce methanol, but only oxygen. This eliminates the use of expensive and unreliable membranes for keeping methanol away from the cathode.
DE 3624054A1 describes an inert electrode from a semiconductive molybdenum cluster chalcogenide that has a catalytic action to reduce oxygen to water in a fuel cell. This mixed cluster material is polycrystalline, has a particle size between 1 μm and 5 μm, which limits the layer thickness on the electrode in a pulverized powder state, and thus is coarsely dispersible after mixing with a solvent. There is a material system. However, the cluster distribution on the electrode surface after application of a small amount of liquid and subsequent evaporation of the solvent is not uniform, which can exacerbate the selective and catalytic properties of the electrode.
From DE 3802236A1, it is possible to produce a powder or thin layer or membrane under the action of heat from a mixture of substances to be reacted (metal carbonyl, chalcogen-containing compound and inert organic solvent), in a fuel cell. It can be known whether it can be used to obtain an inert electrode having a catalytic action of This metal chalcogenide is also polycrystalline and provides a coarse dispersive system in the solvent. This has an agglomerated cluster with a diameter in the μm-range, which is based on its size-in the method of spray pyrolysis deposition disclosed here anyway, at any high material usage. Regardless-it does not result in a uniform distribution in the surface coating on the electrode and may limit the different catalytic and selective effects locally. At this time, the layer thickness of the coating is limited downward depending on the size of the cluster.
The production of such a catalytic material is costly and is possible only in the high temperature range around 1100 ° C. Therefore, other methods were sought to produce materials with similar properties.
The technical level that is the starting point of the present invention is based on the above-mentioned general details, the paper by O. Solorza-Feria et al. “Electrochimica Acta, Vol.39, No.11 / 12 (1994), pp.1647-1653. From this paper, the formula:
The semiconductive cluster material of (Ru 1-x MO x ) y SeO z (0.02 <x <0.04, 1 <y <3, z≈2y) is a metal carbonyl Ru 3 (CO 12 ) and Mo From the mixture of (CO) 6 and selenium it can be seen that it can be obtained by wet chemical-organic low temperature synthesis in xylene as solvent. The resulting mixed cluster is based on two transition metals and one chalcogen. These can be provided in the form of powders or thin layers (<0.5 μm) for the surface coating of the inert cathode. The cluster material in this emerging form has electrocatalytic activity for oxygen reduction in an acidic medium comparable to platinum and reacts selectively. In this case, however, this property is limited by the packing density of the individual clusters in the coating, which is due to the appearance as a powder with agglomerated clusters or as a thin layer with narrow adjacent clusters. Limited and may result in reverse interference with that action of this cluster.
Therefore, the problem underlying the present invention is that the selective acting catalytic material acts to further improve the selectivity and catalytic reaction of oxygen reduction in acidic methanol solutions compared to known emerging materials. And providing an inert cathode having such a surface coating.
This object is achieved according to the invention by having a thin surface coating having a coverage obtained from individual clusters in a uniform distribution of colloidal dispersibility with a low material usage in the ng-range per cm 2 of effective cathode surface area. The
This distribution of individual clusters allows it to exert its full catalysis and selective activity without interfering with it. This activation of the individual clusters results in a high working density. In this case, the possibility of catalysis still exceeds that of the material in the aforementioned appearance. The very finely distributed arrangement of individual clusters having a particle size of the colloidally dispersible, i.e. uniform, development, nm-range (e.g. 3-4 nm) makes the cathode a catalyst poison and this. Effectively protect against reduced activity associated with Expensive membranes are unnecessary. Combined with this improved selectivity during oxygen reduction and the long-term stability associated therewith, the cathode of the present invention with its thin surface coating, for example, which requires a layer thickness of only 6-7 nm, is therefore a powder. Or it has advantages over a thicker coating with a thin layer. Furthermore, due to the wide spatial distribution of the individual clusters resulting in a slight coverage of the cathode surface, the required material usage is correspondingly small and in the ng-range (eg 3.1 ng). Furthermore, the catalytic material is very heat stable and can be heat treated.
Already in this position, prior to subsequent implementations, it is recognized that the above-mentioned advantageous properties of the cathode according to the invention are made possible by the appearance of the catalytic material as a colloidal solution which can itself be easily synthesized. Thus, special tailored products for electrocatalytic activity can be provided.
Semiconducting transition metals, in particular molybdenum (Mo), tungsten (W), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh) and iridium (Ir) and chalcogen sulfur (S), selenium (Se), in particular red selenium and tellurium (Te), are the basis for catalytic materials having a colloidally dispersible cluster distribution. From these elements, a binary cluster and a ternary mixed cluster can be obtained in the presence of oxygen (O), respectively.
According to one embodiment of the inert cathode according to the present invention, the transition metal is ruthenium (Ru), the chalcogen is sulfur (S) or selenium (Se), and the cluster is in the range of 0.5-2. It is advantageous in having a molar ratio (x) of ruthenium (Ru) to chalcogen (S, Se). Such clusters have special resistance to electrolyte acids and provide specially suitable properties during synthesis due to the 8-ring structure in the case of sulfur and red selenium during synthesis.
According to another embodiment of the present invention, a cluster having ruthenium (Ru) as a transition metal and selenium (Se) as a chalcogen is in a stoichiometric form (Ru) n Se (where n is 1. 5 to 2, in particular 1.7). Clusters having this stoichiometric structure as catalytic material meet the requirements of high catalytic activity and selective activity particularly well.
The cathode according to the invention requires an expensive cathode structure using platinum or similar precious metals or compounds, effectively protected against chemical infringement by a thin surface coating of catalytically and selectively highly active materials. And not. Therefore, by carrying out the present invention, the cathode can have a porous and conductive support. This porosity affects the high cathode specific surface area for this reaction. This support may be a suitable cost substrate, in particular from carbon black- or norit-type-carbon, which is particularly suitable for use in gas diffusion electrodes in fuel cells. The gas diffusion electrode has one hydrophobic layer, one hydrophilic layer, and a reactive solid layer therebetween, and is configured in three phases. The use of conventional substrates such as vitrified carbon- or indium-tin-oxide (ITO) substrates is likewise possible.
In a fuel cell having an alkaline electrolyte, the electrolyte may be impure due to carbon dioxide that produces carbonate in an alkaline solution. Thereby, the electroconductivity of this electrolyte and the lifetime of an electrode fall. Therefore, it is most preferred that the fuel cell be constructed using an acidic medium, particularly sulfuric acid, which is most often used as a liquid electrolyte, according to one embodiment of the present invention. The use of phosphoric acid is possible as well, but it is conductive only at high temperatures (300 ° C.).
Direct methanol-fuel cells operate at atmospheric or overpressure and at operating temperatures of 80-100 ° C. Energetic methanol is broken down directly for hydrogen acquisition without bypassing through the reformer. Therefore, in another embodiment of the present invention, it is preferable that the methanol-fuel cell is configured as a direct fuel cell.
According to the present invention, a method for producing the above-described inert cathode for selective oxygen reduction is achieved by placing the porous support of the cathode in a catalytic material in the form of a colloidal solution in order to obtain a thin surface coating in the nm-range. And subsequently dried at room temperature, and thereafter heat-treated at a temperature of 200 to 300 ° C., particularly 208 ° C. Such a process can be carried out without significant costs in terms of equipment and expense, and the best results are already obtained with a single procedure. By immersion in the colloidal catalyst material, the cathode surface is uniformly provided with a liquid surface coating. The colloidal solid component is fixed on the support in a colloidally dispersible and uniform distribution, especially after drying of the coating, which is carried out in vacuum to accelerate the drying process. The impurities present can then be easily evaporated in the heat treatment step without harming the catalyst material.
In this case, according to another aspect of the invention, the colloidal solution is prepared so that the clusters float in the organic solvent in a uniform distribution of colloidal dispersion with the addition of an appropriate amount of long chain stabilizer. In this case, the boiling point (T ss ) of the stabilizer is higher than the boiling point (T sl ) of the solvent. Using such a colloidal solution, the necessary cluster material can be provided with a special view. The solvent is a support material. Long chain stabilizers prevent it from agglomerating into a powder by lamination to the cluster. The amount used can be ascertained via the molar ratio of the individual components, depending on the cluster origin in the solvent. This conversion reaction takes place almost independently of the components used at the boiling point of the solvent (T sl ). The state of the stabilizer boiling point (T ss ) above the solvent boiling point (T sl ) ensures solvent removability without affecting the fine distribution of stabilizers and clusters. Since the stabilizer is removed for the first time in the heat treatment step, only the colloidally dispersible and uniformly distributed clusters are still present on the cathode surface, forming a firm coating.
The production of the colloidal solution can be carried out by wet chemical-organic synthesis, particularly easily and economically advantageously, within the range of the boiling point of the solvent (T sl ) when carrying out the invention. This production method is performed in the same manner as the production method of a known catalyst material in a powder form or a thin layer form. This is based on placing one or more metal carbonyls in a solvent together with one chalcogen. In the present invention, a stabilizer is still added thereto.
The diversity of metal carbonyl M (even as a combination of metal carbonyls) is wide, in particular,
・ M (CO) 6 (M = Mo, W)
M 3 (CO) 12 (M = Ru, Os)
M 4 (CO) 12 (M = Co, Rh, Ir)
M 6 (CO) 16 (M = Co, Rh, Ir)
Containing.
Chalcogen diversity includes X = Se, Te, S. Here, 8-ring-chalcogens, such as red selenium and sulfur, provoke particularly good properties for synthesis, depending on their purity.
As an organic solvent,
Toluene C 6 H 5 CH 3 Tsl = 111 ° C.
・ Xylene C 6 H 4 (CH 3 ) 2 T sl = 139 ° C./140° C.
-Mesitylene C 6 H 3 (CH 3 ) 3 T sl = 165 ° C
Is preferred.
The diversity of long chain stabilizers is similarly wide. In particular,
According to the invention, it is particularly advantageous if the solvent is xylene having a boiling point (T sl ) of 140 ° C. and the stabilizer is 1-octadecanethiol having a boiling point (T ss ) of 185 ° C. Clusters with ruthenium (Ru) as transition metal and selenium (Se) as chalcogen are in stoichiometric form (Ru) n Se, where n is 1.5-2, in particular 1.7. In order to obtain an optimum cathode with excellent catalytic and selective properties, in conjunction with the aforementioned further embodiment of the inert cathode according to the invention and a temperature of 208 ° C. Added. At this time, based on the distribution of the colloidal dispersibility, only about 3.1 ng of the catalyst material per 1 cm 2 of the effective electrode surface area is necessary, which is extremely advantageous in terms of cost.
The synthesis of this catalytic material is now briefly described:
In a flask equipped with a reflux condenser, the solvent xylene (100 ml) is flushed with argon for 10 minutes to remove any oxygen that should react with the components. The powdered selenium (18 mg; 22.8 μM) is then dissolved in xylene by heating to 140 ° C. and the solution is again cooled to room temperature. To this is added the semiconductive transition metal carbonyl triruthenium dodeca-carbonyl (Ru 3 (CO) 12 ; 72.9 mg; 11.4 μM) and the stabilizer 1-octadecanethiol (220 mg; 76.9 μM). . In this case, the amount of the stabilizer is about 3 times the amount of carbonyl when the molar ratio is 6.75. Cluster formation proceeds after about 20 hours of heating to 140 ° C. xylene-boiling point (Tsl). The colloid is constantly stirred during this reaction and cooled by reflux cooling.
The provision of a substrate for the deposition of powders or thin layers during cluster formation as is known in the state of the art is unnecessary in the production of this colloid. The yield is 100%, ie all of the charged material is reacted. For example, there is no loss due to deposition on the inner surface of the flask as is known during powder formation.
The formed cluster has a dimension of 3 nm to 4 nm. The stoichiometric composition by Rutherford backscattering (RBS) measured on a thin layer of 6 nm to 7 nm on a glassy carbon substrate is a particularly advantageous embodiment of the invention. Yields Ru 1.7 Se as described in.
In the figure, several identical heat-treated electrode plates made of vitrified carbon in 0.5 M sulfuric acid, each coated with a thin layer from 5 μl of colloidal solution of catalytic agent Ru 1.7 Se The negative course of the electrochemical oxygen reduction current is shown in relation to the electrode potential (NHE-standard hydrogen electrode, standard electrode). Here, the vertical line along the curve represents a slight error width of the measurement performed several times. This process remains unchanged after the addition of 1M of methanol, suggesting a high selectivity of the inert cathode according to the invention. The active range is in the lower linear part of this curve, which is better than that of platinum when using methanol, which is a good indication for the cathode according to the invention having a uniform surface coating derived from colloidal dispersible colloids. Proven catalytic properties.
Claims (8)
前記表面被覆は、
（１）有効陰極表面積１ｃｍ ２ 当たりｎｇ−範囲の被覆度を有し、
（２）陰極の多孔性支持体を前記触媒物質のコロイド溶液中に浸漬させ、室温で乾燥させ、その後、２００〜３００℃、殊に２０８℃の温度で熱処理することにより得られ、
（３）前記コロイド溶液が、有機溶剤の沸点（Ｔ ｓｌ ）よりも沸点（Ｔ ｓｓ ）が上である長鎖状安定剤の添加下に、有機溶剤の沸点（Ｔ ｓｌ ）の範囲内で湿式化学−有機的に合成され、これによりクラスターが溶剤中にコロイド分散性の均一分布で浮遊する、その際、長鎖状安定剤は、１−ノナンチオール、１−ドデカンチオール、１−オクタデカンチオール、２，４−ｔｅｒｔ−ブチルフェノール、２，６−ジ−ｓｅｃ−ブチルフェノール又は２，６−ジ−ｔｅｒｔ−ブチルフェノールから選択されている、および
（４）前記安定剤の使用量は、個々のクラスター成分のモル比で決められる、ことを特徴とする、陰極。 Methanol - for fuel cells, in negative poles that have a surface catalytic coating you based semiconductive cluster from at least one transition metal and one chalcogen,
The surface coating is
(1) having a coverage in the ng-range per cm 2 of effective cathode surface area ;
(2) It is obtained by immersing the porous support of the cathode in the colloidal solution of the catalyst substance, drying at room temperature, and then heat-treating at a temperature of 200 to 300 ° C, particularly 208 ° C.
(3) The colloidal solution is wet within the range of the boiling point (T sl ) of the organic solvent with the addition of a long-chain stabilizer whose boiling point (T ss ) is higher than the boiling point (T sl ) of the organic solvent. Chemically-organically synthesized, whereby the clusters float in a uniform distribution of colloidal dispersion in the solvent, in which case the long chain stabilizer is 1-nonanethiol, 1-dodecanethiol, 1-octadecanethiol, Selected from 2,4-tert-butylphenol, 2,6-di-sec-butylphenol or 2,6-di-tert-butylphenol, and
(4) the amount of the stabilizer is determined by the molar ratio of the individual cluster component, characterized in that, Yin pole.
（１）前記陰極の多孔性支持体を前記触媒物質のコロイド溶液中に浸漬させ、
その際、（a）前記コロイド溶液が、有機溶剤の沸点（Ｔ ｓｌ ）よりも沸点（Ｔ ｓｓ ）が上である長鎖状安定剤の添加下に、有機溶剤の沸点（Ｔ ｓｌ ）の範囲内で湿式化学−有機的に合成され、これによりクラスターが溶剤中にコロイド分散性の均一分布で浮遊する、その際、長鎖状安定剤は、１−ノナンチオール、１−ドデカンチオール、１−オクタデカンチオール、２，４−ｔｅｒｔ−ブチルフェノール、２，６−ジ−ｓｅｃ−ブチルフェノール又は２，６−ジ−ｔｅｒｔ−ブチルフェノールから選択されている、
（b）前記安定剤の使用量が、個々のクラスター成分のモル比で決められる、および
（２）室温で乾燥させ、その後、
（３）２００〜３００℃、殊に２０８℃の温度で熱処理すること、
を特徴とする、陰極を製造する方法。 Methanol - for a fuel cell, a method for producing a negative electrode that have a surface catalytic coating you based semiconductive cluster from at least one transition metal and one chalcogen,
(1) immersing the porous support of the cathode in a colloidal solution of the catalytic material;
In that case, (a ) the range of the boiling point (T sl ) of the organic solvent with the addition of a long chain stabilizer whose boiling point (T ss ) is higher than the boiling point (T sl ) of the organic solvent. In which the clusters float in a uniform distribution of colloidal dispersion in the solvent, in which case the long-chain stabilizers are 1-nonanethiol, 1-dodecanethiol, 1- Selected from octadecanethiol, 2,4-tert-butylphenol, 2,6-di-sec-butylphenol or 2,6-di-tert-butylphenol,
(B) the amount of stabilizer used is determined by the molar ratio of the individual cluster components; and
(2) Dry at room temperature, then
(3) heat-treating at a temperature of 200 to 300 ° C., particularly 208 ° C.,
And wherein, how to produce a negative electrode.
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| DE19644628A DE19644628C2 (en) | 1996-10-17 | 1996-10-17 | Process for the preparation of an inert cathode for selective oxygen reduction and application of the cathode produced |
| DE19644628.7 | 1996-10-17 | ||
| PCT/DE1997/002453 WO1998018171A1 (en) | 1996-10-17 | 1997-10-16 | Inert cathode for selective reduction of oxygen and a method for the production thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19914661C2 (en) * | 1999-03-31 | 2002-11-14 | Joerg Mueller | Process for the production of an integrated interconnected polymer electrolyte membrane fuel cell |
| DE19914680C2 (en) * | 1999-03-31 | 2003-02-20 | Joerg Mueller | Polymer electrolyte membrane with integrated catalyst metal-doped porous graphite contact layer |
| DE19914681C2 (en) * | 1999-03-31 | 2002-07-18 | Joerg Mueller | Polymer electrolyte membrane Fuel cell system in microsystem technology |
| DE10052189B4 (en) * | 2000-10-21 | 2007-09-06 | Daimlerchrysler Ag | A multilayer gas diffusion electrode of a polymer electrolyte membrane fuel cell, a membrane electrode assembly, a method of manufacturing a gas diffusion electrode and a membrane electrode assembly, and use of the membrane electrode assembly |
| US7879753B2 (en) * | 2003-05-27 | 2011-02-01 | Industrie De Nora S.P.A. | Catalyst for oxygen reduction |
| JP2005317288A (en) * | 2004-04-27 | 2005-11-10 | Japan Science & Technology Agency | Platinum-free sulfide type fuel cell catalyst, and manufacturing method of same |
| KR100684767B1 (en) * | 2005-07-29 | 2007-02-20 | 삼성에스디아이 주식회사 | Catalyst for cathode used in fuel cell, membrane-electrode assembly and fuel cell system comprising same |
| EP1772916A3 (en) | 2005-08-31 | 2009-01-28 | Samsung SDI Co., Ltd. | Catalyst for Cathode of Fuel Cell, and Membrane-Electrode Assembly for Fuel Cell |
| KR101223630B1 (en) * | 2005-11-11 | 2013-01-17 | 삼성에스디아이 주식회사 | Catalyst for cathode of fuel cell, method of preparing same, membrane-electrode assembly and fuel cell comprising same |
| US9012107B2 (en) | 2005-11-11 | 2015-04-21 | Samsung Sdi Co., Ltd. | Cathode catalyst for fuel cell, method of preparing same, and membrane-electrode assembly comprising same |
| KR100684853B1 (en) | 2005-11-30 | 2007-02-20 | 삼성에스디아이 주식회사 | Cathode catalyst for fuel cell, membrane-electrode assembly for fuel cell comprising same and fuel cell system comprising same |
| JP4745988B2 (en) * | 2006-01-18 | 2011-08-10 | 三星エスディアイ株式会社 | FUEL CELL CATALYST CATALYST AND ITS MANUFACTURING METHOD, FUEL CELL MEMBRANE-ELECTRODE ASSEMBLY CONTAINING THE CATHODE CATALYST, AND FUEL CELL SYSTEM |
| KR100766977B1 (en) * | 2006-03-31 | 2007-10-12 | 삼성에스디아이 주식회사 | Cathode catalyst for fuel cell, and membrane-electrode assembly for fuel cell and fuel cell system comprising same |
| KR100766976B1 (en) | 2006-04-28 | 2007-10-12 | 삼성에스디아이 주식회사 | Catalyst for cathod of fuel cell, method for preparing same, and membrane-electrode assembly for fuel cell and fuel cell system comprising same |
| KR100728182B1 (en) | 2006-05-12 | 2007-06-13 | 삼성에스디아이 주식회사 | Cathode catalyst for fuel cell, membrane-electrode assembly for fuel cell comprising same, and system for fuel cell comprising same |
| KR100728188B1 (en) * | 2006-05-16 | 2007-06-13 | 삼성에스디아이 주식회사 | Cathode catalyst for fuel cell, membrane-electrode assembly for fuel cell comprising same and fuel cell system comprising same |
| JP2009007647A (en) * | 2007-06-29 | 2009-01-15 | Hitachi Ltd | Organic hydride manufacturing apparatus and distributed power supply and automobile using the same |
| JP4530003B2 (en) | 2007-07-12 | 2010-08-25 | トヨタ自動車株式会社 | Fuel cell electrode catalyst and solid polymer fuel cell using the same |
| JP5056236B2 (en) * | 2007-07-24 | 2012-10-24 | トヨタ自動車株式会社 | ELECTRODE CATALYST FOR FUEL CELL, METHOD FOR EVALUATING PERFORMANCE OF OXYGEN REDUCTION CATALYST, AND SOLID POLYMER FUEL CELL |
| JP5056256B2 (en) * | 2007-08-09 | 2012-10-24 | トヨタ自動車株式会社 | ELECTRODE CATALYST FOR FUEL CELL, METHOD FOR EVALUATING PERFORMANCE OF OXYGEN REDUCTION CATALYST, AND SOLID POLYMER FUEL CELL |
| JP5056257B2 (en) * | 2007-08-09 | 2012-10-24 | トヨタ自動車株式会社 | ELECTRODE CATALYST FOR FUEL CELL, METHOD FOR EVALUATING PERFORMANCE OF OXYGEN REDUCTION CATALYST, AND SOLID POLYMER FUEL CELL |
| JP5056258B2 (en) * | 2007-08-09 | 2012-10-24 | トヨタ自動車株式会社 | ELECTRODE CATALYST FOR FUEL CELL, METHOD FOR EVALUATING PERFORMANCE OF OXYGEN REDUCTION CATALYST, AND SOLID POLYMER FUEL CELL |
| JP2009082910A (en) | 2007-09-14 | 2009-04-23 | Toyota Motor Corp | Fine-particle composite, process for producing the fine-particle composite, catalyst for solid polymer electrolyte fuel cell, and solid polymer electrolyte fuel cell |
| JP5678499B2 (en) * | 2010-07-15 | 2015-03-04 | トヨタ自動車株式会社 | Lithium air battery |
| FR2992234B1 (en) * | 2012-06-22 | 2016-12-09 | Centre Nat De La Rech Scient (C N R S) | PROCESS FOR THE PREPARATION OF CATALYST NANOPARTICLES FOR THE CATHODIC REDUCTION OF DIOXYGEN IN THE PRESENCE OF METHANOL |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3624054A1 (en) * | 1986-07-14 | 1988-01-21 | Hahn Meitner Kernforsch | Inert electrode with catalytic activity |
| JPS63252908A (en) * | 1987-04-08 | 1988-10-20 | Agency Of Ind Science & Technol | Immobilized oxide of metallic fine particle, production thereof, oxidation catalyst, reduction catalyst, combustible gas sensor element and catalyst for electrode |
| DE3802236A1 (en) * | 1988-01-22 | 1989-08-03 | Hahn Meitner Kernforsch | Mixture of material for producing a metal chalcogenide and use of such a mixture |
| ATE136949T1 (en) * | 1988-11-17 | 1996-05-15 | Physical Sciences Inc | ELECTROCATALYST, METHOD FOR PRODUCTION, ELECTRODES PRODUCED THEREFROM AND METHOD OF USE THEREOF |
| US5338334A (en) * | 1992-01-16 | 1994-08-16 | Institute Of Gas Technology | Process for preparing submicron/nanosize ceramic powders from precursors incorporated within a polymeric foam |
-
1996
- 1996-10-17 DE DE19644628A patent/DE19644628C2/en not_active Expired - Fee Related
-
1997
- 1997-10-16 JP JP51883598A patent/JP4235986B2/en not_active Expired - Fee Related
- 1997-10-16 AU AU52216/98A patent/AU5221698A/en not_active Abandoned
- 1997-10-16 CA CA002269051A patent/CA2269051A1/en not_active Abandoned
- 1997-10-16 WO PCT/DE1997/002453 patent/WO1998018171A1/en not_active Application Discontinuation
- 1997-10-16 EP EP97947016A patent/EP0947016A1/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| CA2269051A1 (en) | 1998-04-30 |
| JP2001502467A (en) | 2001-02-20 |
| DE19644628A1 (en) | 1998-04-23 |
| DE19644628C2 (en) | 2001-05-23 |
| WO1998018171A1 (en) | 1998-04-30 |
| EP0947016A1 (en) | 1999-10-06 |
| AU5221698A (en) | 1998-05-15 |
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