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公开(公告)号：US5084144A
公开(公告)日：1992-01-28
申请号：US560206
申请日：1990-07-31
CPC分类号： H01M4/8807 , H01M4/8668 , H01M4/8853 , H01M4/926 , H01M8/08 , H01M8/1004 , H01M2300/0082 , H01M8/1007 , H01M8/1009 , Y02P70/56 , Y10S205/917
摘要： Gas-diffusion electrodes (GDE's) suitable for use with a solid polymer electrolyte (s.p.e.), particularly in s.p.e. fuel cells, which GDE's provide unusually highly efficient use of noble or precious electrocatalytic metals, are obtained by starting with a GDE which is essentially fully fabricated except for electrocatalytic metal treatment and s.p.e. treatment, e.g. a carbon GDE having a gas-permeable hydrophobic face and a particulate carbon-containing catalytic face. This untreated GDE is treated bya. impregnating an s.p.e. solutuion into the catalytic face until the solution penetrates part way into the cross-section of the GDE, especially into the carbon particulate or other support material, but not as far as the hydrophobic, gas permeable face,b. inserting the thus-treated GDE and a counterelectrode into a plating bath containing, for example, M.sup.+, M.sup.++, and/or M.sup.+++ ions, where M is a metal of Group VIII or I-B of the Periodic Table, andc. applying an interrupted current (periodically interrupted or a single, long pulse
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公开(公告)号：US5132193A
公开(公告)日：1992-07-21
申请号：US665789
申请日：1991-03-07
CPC分类号： H01M4/92 , H01M8/1007 , H01M8/1009 , H01M2004/8684 , H01M2300/0002 , H01M2300/0008 , H01M2300/0011 , H01M2300/0025 , H01M2300/0082 , H01M8/1004
摘要： In this method, a lower alcohol is oxidized directly (i.e. without reformation) to CO.sub.2 +H.sub.2 O at the anode of a fuel cell, and a reducible gas (e.g. air or O.sub.2) is reduced at the cathode. High, reasonably constant current densities at low over-voltages can be obtained. The electrolyte is preferably an acidic solid polymer electrolyte, and the anode comprises, as the electrocatalyst, a combination of a Group VIII noble metal with gold having significant Au (111) character. The (111) face of gold crystals (preferably crystals in the size range of about 4 to 15 nm) have been found to be specific for oxidation of intermediate alcohol oxidation products (CO, CHO, COH, HCHO, CH.sub.3 CHO, etc.) to CO.sub.2 or CO.sub.2 +H.sub.2 O. Thus, the combination of a Group VIII metal such as Pt with Au (111) avoids "poisoning" of the Pt by these intermediate products. Some protection against such "poisoning" is also provided with Au (110), but Au (100) and polycrystalline gold are not considered useful in the electro-oxidation of lower alcohols (particularly methanol and ethanol). If the alcohol "fuel" is methanol, the combination of Group VIII noble metal and Au (111) should be microscopically homogeneous (e.g. Pt/Au cubo-octahedral crystals with a high level of (111) faceting), but if the "fuel" is ethanol, the Group VIII noble metal and the Au (111) can be combined in various ways, including macroscopic homogeneous mixtures and heterogeneous blends.
摘要翻译： 在这种方法中，低级醇在燃料电池的阳极处被直接氧化（即不重整）氧化成CO 2 + H 2 O，并且在阴极处还原可还原气体（例如空气或O 2）。 可以获得在低过电压下的高，相当恒定的电流密度。 电解质优选为酸性固体聚合物电解质，阳极包含作为电极催化剂的VIII族贵金属与具有显着Au（111）特性的金的组合。 已经发现金结晶（111）表面（优选大约4-15nm的晶体）对于中间体醇氧化产物（CO，CHO，COH，HCHO，CH 3 CHO等）的氧化是特异性的， CO2或CO2 + H2O。 因此，第Ⅷ族金属如Pt与Au（111）的组合避免了这些中间产物对Pt的“中毒”。 Au（110）还提供了一些防止这种“中毒”的保护措施，但Au（100）和多晶金不被认为是低级醇（特别是甲醇和乙醇）的电氧化有用的。 如果醇“燃料”是甲醇，则第VIII族贵金属和Au（111）的组合应该是微观均匀的（例如具有高水平（111）刻面的Pt / Au立方八面体晶体），但是如果“燃料 “是乙醇，第VIII族贵金属和Au（111）可以以各种方式组合，包括宏观均匀混合物和异质混合物。
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3.发明授权Electrode for current-limited cell, cell including the electrode method for using the cell and a method of making the electrode 失效用于电流限制电池的电极，包括使用电池的电极方法的电池和制造电极的方法
公开(公告)号：US5085743A
公开(公告)日：1992-02-04
申请号：US518071
申请日：1990-05-02
IPC分类号： G01N27/30
CPC分类号： G01N27/30
摘要： The gas-sensing electrodes prepared according to this invention are specifically designed for cells which operate in a current-limited mode, i.e. at current densities well below 20 mA/cm.sup.2. Such cells are particularly useful to measure or detect a gaseous component of a gaseous environment or stream, provided the gaseous component can be electrochemically oxidized or reduced. In an alkaline, metal-oxygen cell for example, an electrode of this invention can be used as an oxygen cathode. The electrode is prepared by:(a) bringing an exposed face of a self-supporting, electrically-conducting sheet of fibrous or sintered-particle material having a thickness of at least about 30 .mu.m and a flexural strength of at least 2000 kPa into contact with an electrolyte containing ions of a catalytic metal, the electrolyte also being in contact with a counterelectrode,(b) applying a pulsed-D.C. current which tends to favor electroplating of metal and strong adherence of the plated metal to the electrically-conducting sheet, so that a continuous electrodeposited layer of catalytic metal is formed, and(c) applying a hydrophobic layer to the thus-plated face, this hydrophobic layer being thick enough to limit gas diffusion into the cross-section of the sheet, so that the resulting electrode will operate in a current-limited mode, but not so thick as to have a significant adverse effect upon the response time of the cell.
摘要翻译： 根据本发明制备的气体感测电极被专门设计用于以限流模式操作的电池，即在远低于20mA / cm 2的电流密度下工作的电池。 这样的电池特别可用于测量或检测气态环境或流的气体组分，条件是气态组分可被电化学氧化或还原。 例如，在碱金属 - 氧电池中，可以使用本发明的电极作为氧阴极。 电极通过以下步骤制备：（a）将具有至少约30μm的厚度和至少2000kPa的弯曲强度的自支撑导电的纤维或烧结颗粒材料片的暴露面引入 与含有催化金属离子的电解液接触，电解质也与反电极接触，（b）施加脉冲DC 倾向于有利于电镀金属的电流和电镀金属对导电片的强粘附性，从而形成催化金属的连续的电沉积层，（c）在这样镀上的表面上涂敷疏水层， 疏水层足够厚以限制气体扩散到片材的横截面中，使得所得电极将以限流模式操作，但不太厚以致对电池的响应时间具有显着的不利影响 。
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