WO1992002965A1 - Production d'electricite a l'aide d'une pile a combustible utilisant un combustible a l'alcool - Google Patents

Production d'electricite a l'aide d'une pile a combustible utilisant un combustible a l'alcool Download PDF

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Publication number
WO1992002965A1
WO1992002965A1 PCT/US1991/005611 US9105611W WO9202965A1 WO 1992002965 A1 WO1992002965 A1 WO 1992002965A1 US 9105611 W US9105611 W US 9105611W WO 9202965 A1 WO9202965 A1 WO 9202965A1
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WIPO (PCT)
Prior art keywords
anode
face
gold
cathode
fuel cell
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PCT/US1991/005611
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English (en)
Inventor
Vilambi N. R. K. Reddy
Earl J. Taylor
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Physical Sciences Inc.
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Filing date
Publication date
Priority claimed from US07/665,789 external-priority patent/US5132193A/en
Application filed by Physical Sciences Inc. filed Critical Physical Sciences Inc.
Publication of WO1992002965A1 publication Critical patent/WO1992002965A1/fr

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/90—Selection of catalytic material
    • H01M4/92—Metals of platinum group
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1007—Fuel cells with solid electrolytes with both reactants being gaseous or vaporised
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1009—Fuel cells with solid electrolytes with one of the reactants being liquid, solid or liquid-charged
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M2004/8678—Inert electrodes with catalytic activity, e.g. for fuel cells characterised by the polarity
    • H01M2004/8684—Negative electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0002—Aqueous electrolytes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0002—Aqueous electrolytes
    • H01M2300/0005—Acid electrolytes
    • H01M2300/0008—Phosphoric acid-based
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0002—Aqueous electrolytes
    • H01M2300/0005—Acid electrolytes
    • H01M2300/0011—Sulfuric acid-based
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0025—Organic electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0065—Solid electrolytes
    • H01M2300/0082—Organic polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1004—Fuel cells with solid electrolytes characterised by membrane-electrode assemblies [MEA]
    • 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

Definitions

  • This invention relates to the generation of electricity by means of the oxidation of an alcohol "fuel” in a fuel cell.
  • An aspect of this invention relates to the use of a fuel cell having gas-diffusion electrodes and a suitable electrolyte, preferably an acidic solid polymer electrolyte, all designed or selected to provide an efficient "direct” (non-reformed) alcohol/air or alcohol/oxygen fuel cell which produces current densities in excess of 50 mA/cm 2 , preferably in excess of 90 mA/cm 2 .
  • Still another aspect of this invention relates to the "direct" use of a lower primary alcohol fuel (particularly methanol or ethanol) in a fuel cell, wherein the electrocatalyst employed in the fuel cell anode is resistant to CO or carbonyl or COH or aldehyde poisoning.
  • Still another aspect of this invention relates to a method for generating electricity in a small or compact, on-site, alcohol-fueled fuel-cell electric power plant or source, e.g. a method for powering a portable appliance or an electric vehicle with an alcohol/air or alcohol/oxygen fuel cell.
  • direct alcohol fuel cells particularly direct methanol fuel cells (DMFC's) are presently under intense study as possible power plants for electric-powdered vehicles (automo ⁇ biles, buses, trucks, golf-carts, etc.). It has been known at least since the 1950 , s that lower primary alcohols, particularly the C ⁇ to c 5 -primary alcohols can be oxidized directly (i.e. without reformation to H 2 + CO or H 2 + C0 2 ) at the anode of a fuel cell. The recent renewed interest in "direct” alcohol fuel cells has been spurred by persistent automobile exhaust-produced air pollution problems in highly developed nations such as the United States, Japan, and the nations of Western Europe. One approach to the virtual elimination of automobile exhaust pollution is the replacement of all types of internal combustion engines with electric motors, and fuel cells show the greatest technical promise for light-weight, compact, high-density sources of electricity.
  • DMFC's direct methanol fuel cells
  • reformers Because small size (compactness) is of such crucial importance in electric cells utilized to power wheeled vehicles, the use of reformers is not the ideal way to enable the fuel cell to utilize alcohol fuels. (Reformers typically convert methanol to hydrogen, carbon dioxide and carbon monoxide, and the hydrogen then becomes the fuel fed to the anode of the fuel cell.) Serious technical drawbacks have also been encountered with exotic ways of storing or providing hydrogen, e.g. in the form of readily decomposable metal hydrides.
  • a "direct" (non-reformed) alcohol fuel cell is that the cell itself is very compact, and no energy is used up in reformation; moreover the fuel is easily stored in liquid form, is high in hydrogen content (almost as high as in hydrocarbons), is highly reactive in a conventional fuel cell, and is economi ⁇ cally viable (at least in the case of the C ⁇ -C 5 alcohols, particularly methanol and ethanol).
  • the preferred reaction products are carbon dioxide and water, and the carbon dioxide is "reject ⁇ ed" by the electrolyte, so that C0 2 removal is automatically provided for.
  • the most active catalysts for direct alcohol oxidation appear to be the metals of the second and third triad of Group VIII of the Periodic Table of Elements, particularly platinum. Accordingly, the chemical mechanisms by which platinum is "poisoned" during electro-oxidation of alcohols on a platinum surface have been intensely studied over the last twenty years or so.
  • the most interesting system for study has been the electro-oxidation of methanol to carbon dioxide and water via various reaction intermediates, which intermediates appear to include formaldehyde (HCHO) and formic acid (HCOOH), possibly adsorbed CO (CO ads ), and possibly adsorbed CHO (CHO ads ) or -COH
  • the species -COH is responsible for the rapid dimunition of current. See D.S. Cameron et al. Platinum Metals Rev..21, 173-181 (1987), page 175.
  • Another theory is that methanol is oxidized on platinum to a strongly adsorbed species by irreversible dehydrogenation, and the chemisorbed "poison" is CO atjs .
  • various species containing a carbonyl group can be chemisorbed on platinum.
  • gold which is resistant to "poisoning" by carbonyl groups or carbonyl-contain ⁇ ing species, should be somehow utilized in a direct methanol fuel cell catalyst, e.g.
  • Group VIII metal/gold catalysts can be very effective as anode electrocatalysts in direct alcohol fuel cells, provided the gold is in the form of tiny crystals with a large proportion of exposed Au (111) crystal faces or facets.
  • the proportion of Au (110) faces is smaller, and it is particularly preferred that the proportion of Au (100) faces be minimized to the utmost extent.
  • the presence of polycrystalline gold is preferably also minimized. In other words, there is a pronounced structure sensitivity for lower alcohol oxidation on gold, particularly in the case of methanol.
  • An Au (111) crystalline gold catalyst can provide a high performance, stable catalyst for the electro-oxidation of methanol to C0 2 and H 2 0 at positive potentials in the range of 500 to 1000 mV (vs. a reversible hydrogen electrode), an admittedly rather high voltage range which could detract from the overall cell voltage (E ce * j ⁇ ).
  • the presence of the Group VIII noble-metal in the alloy (useful for all C ⁇ -C 5 primary alcohols, including methanol) or mixture (useful for C 2 -C 5 alcohols) sharply diminishes the need for a high positive potential vs. RHE (reversible hydrogen electrode) and thereby helps to provide a practical anode electrocatalyst for a direct alcohol fuel cell.
  • this invention relates to a method for generating electricity in a direct alcohol fuel cell wherein the anode of the cell comprises a first, fluid-permeable face and a second face in contact with an electrolyte, preferably an acidic solid polymer electrolyte (s.p.e.), in which the lower primary alcohol is brought into contact with the fluid-permeable face of the anode, thereby permitting the alcohol (which is preferably in vapor form) to penetrate deeply into the cross-section of the anode toward the second face —generally at least as far as the second face and even as far as the electrolyte, so that the alcohol will be in intimate contact with the electrocatalyst on the second face.
  • an electrolyte preferably an acidic solid polymer electrolyte (s.p.e.)
  • This electrocatalyst is a particulate metal comprising a noble metal of Group VIII of the Periodic Table of the Elements (preferably platinum) and crystalline gold having a high proportion of exposed Au (111) crystal faces or facets.
  • the catalytic metal should be substantially an alloy (microscopically homogeneous combination) comprising Pt and Au (111), but in the case of higher alcohols such as ethanol, the catalytic metal can be an unalloyed mixture (a macroscopically homogeneous combination or a heterogeneous blend) comprising Pt and Au (111).
  • the lower primary alcohol is oxidized to carbon dioxide and water at the second face of the anode, "poisoning" by adsorbed reaction intermediates being avoided or minimized.
  • the overall fuel cell reaction is completed by reducing a reducible gas such as air or oxygen at the cathode, resulting in the flow of electricity through the external circuit connecting the cathode to the anode.
  • Cell potentials are adequate (e.g. E cell > 300 mV) and stable, reliable current densities in excess of about 50 mA/cm 2 (e.g. > 90 mA/cm 2 ) can be achieved.
  • the overall structure of the fuel cell preferably conforms to known designs, e.g. known designs for solid polymer electrolyte (s.p.e.) fuel cells having gas diffusion-type anodes and cathodes capable of providing a three-way interface (gas/ electrocatalyst/s.p.e:) for the oxidation of the fuel vapor at the anode and the reduction of air or oxygen to water at the cathode.
  • gas/ electrocatalyst/s.p.e: gas diffusion-type anodes
  • cathodes capable of providing a three-way interface
  • gas/ electrocatalyst/s.p.e: gas diffusion-type anode structure
  • a gas diffusion-type anode structure can accommodate a liquid fuel.
  • the alcohol fuel be vaporized to a gaseous fluid and then fed to the fluid-permeable side of a gas-diffusion anode.
  • This vaporization can be carried out by heating the alcohol fuel directly or by passing an inert carrier gas (e.g. N 2 ) through it.
  • an inert carrier gas e.g. N 2
  • the structure of a typical gas-diffusion electrode typically comprises (1) a fluid-permeable or "gas" side or face with hydrophobic characteristics imparted by a fluorinated polymer such as polytetrafluoroethylene (PTFE) or polytrifluorochloro- ethylene or a copolymer of tetrafluoroethylene and a second fluorinated monomer, and (2) a catalytic side or face provided with a particulate electrocatalyst.
  • PTFE polytetrafluoroethylene
  • PTFE polytetrafluoroethylene
  • copolymer of tetrafluoroethylene and a second fluorinated monomer a second fluorinated monomer
  • the catalytic face is in direct contact with a liquid or solid electrolyte.
  • solid polymer electrolytes are preferred because of their excellent "cold start" capabilities and other advantages relating to ease of manufacture and avoidance of evaporation problems.
  • Reliable acidic s.p.e.'s are commercially available, e.g. the sulfonated fluorinated polymer membrane-like materials sold under the trademark NAFION by E. I. duPont deNemours and Co. of Wilmington, Delaware, U.S.A.
  • Such membrane ⁇ like materials have a fluorinated olefin homopolymer or copolymer "backbone” and pendent partially or fully fluorinated hydrocarbon and/or ether chains or groups terminated with acidic groups, preferably -SO.-.H, but phosphonic acid or boric acid-type groups are also known from the patent literature.
  • the air or oxygen cathode of a fuel cell used in this invention can, if desired, be conventional in every respect.
  • the electrocatalyst at the cathode is therefore a "supported" Group VIII metal such as Pt, the "support” material being high surface area carbon or the like.
  • the electrocatalyst layer deposited on the catalytic face of the anode is believed to be novel and believed to have unique characteristics. The formation of this catalytic layer is described subsequently.
  • a fully assembled fuel cell used in this invention can have any of the known stack configurations designed for compactness and efficient supply of gaseous fuels and oxidant gas to the fluid-permeable faces of the cathodes and anodes. Any of the conventional means for providing a steady stream or flow of fuel vapor to the anode and reducible gas (e.g. air or oxygen) to the cathode can be used. Electrode leads and external circuitry can also be conventional. Typically, an electric motor will be included in the external circuit.
  • anode electrocatalyst Two general types of anode electrocatalyst are contemplated by this invention, one type is simply a mass of crystalline gold particles predominating in Au (111) faces (typically these particles are “supported” either on high-surface area carbon particles or on so-called “conductive ceramic” particles) blended with conventional "supported” platinum particles.
  • the blend can be very intimate, hence acroscopically homogeneous, but alloying (microscopic homogeneity) of Pt and Au (111) is not necessary.
  • this physically admixed or blended electrocatalyst is preferred for use only with primary alcohols higher than methanol, most preferably —for economic reasons— ethanol.
  • unsupported, essentially monocrystalline Au (111) particles can be blended with supported or unsupported Pt particles.
  • the other type of electrocatalytic metal is microscopically homogeneous and more properly called an alloy, since any given metallic particle can include atoms of both gold and platinum.
  • This alloy which predominates in (111) crystal faces, is useful with any of the ⁇ to C 5 primary alcohol fuels, including CH 3 OH.
  • Gold and platinum both form face-centered cubic (f.c.c.) crystals, and Au/Pt blends form homogeneous solid solutions in any desired proportions.
  • Methanol is easily stripped of its hydrogen atoms by a platinum catalyst under electro-oxidation conditions.
  • the result of this proton or free-radical H loss is believed to be strongly chemisorbed carbon and oxygen-containing species (e.g. CO and/or CHO) which are difficult to oxidize further.
  • oxygen-containing species e.g. CO and/or CHO
  • Such species are so strongly adsorbed on Pt that they will not migrate to another catalytic site (a "site” in this context being an area the size of, say, 1.5 to 10 nanometers or 15 to 100A), but if Au (111) is present at the site, further oxidation to CO- or C0 2 + H 2 0 can occur. This further oxidation reverses or prevents any "poison ⁇ ing", hence the oxidation reaction continues unabated.
  • site in this context being an area the size of, say, 1.5 to 10 nanometers or 15 to 100A
  • the cyclic voltammagram for the electro-oxidation of ethanol in platinum appears to be very analogous to that for methanol. However, the similarity of these cyclic voltammagrams may be somewhat deceptive.
  • the mechanism of ethanol electro-oxidation is believed to include the following steps:
  • the adsorbed acetaldehyde (CH 3 CHO ads ) is relatively easily displaced from the catalytic site, e.g. by a flow of incoming ethanol molecules. Accordingly, it is only necessary that the Au (111) crystal face be nearby, not that it be part of the site.
  • the Au/Pt alloy mixture be "supported" by high surface area carbon or high surface area electrically conductive oxides or ceramics and the like.
  • Suitable finely-divided carbons are commercially available in B.E.T. surface areas ranging from 50 m 2 per gram to > 1000 m 2 /g and even approaching 2000 m 2 /g.
  • the carbon can be graphi- tized to make it more corrosion-resistant.
  • Conductive oxides preferably have surface areas >50 m 2 /g also.
  • Preferred conduc ⁇ tive oxides are sub-oxides of titanium.
  • the high surface area carbon is preferably suspended in a polar solvent comprising water and a lower aliphatic alcohol such as isopropyl alcohol.
  • a polar solvent comprising water and a lower aliphatic alcohol such as isopropyl alcohol.
  • Reducible gold salts or acids such as gold (III) chloride or chloroauric acid (HAuCl 4 ) and reducible Pt salts such as platinum chloride, chloroplatinic acid, etc. will dissolve in the polar solvent, and the carbon will be impregnated with the dissolved salt or acid.
  • Separate batches of carbon, one impregnated with gold-containing ions and one impregnated with platinum-containing ions are each dried (e.g.
  • the Au/C particles are sintered at elevated temperatures to increase the particle size to >40 A and less than about 150 A to maximize the occurrence of Au (111) and Au (110) faces, particu ⁇ larly Au (111) faces or puzzle »ng.
  • the Au/C can then be mixed with the Pt/C to provide an electrocatalyst especially suited to the electro-oxidation of ethanol.
  • Pt (111) "seeding" is effected, or Pt and Au compounds (e.g. a mixture of chloroauric and chloroplatinic acids) are codeposited, or deposited seriatim, on carbon using the polar solvent, drying, and H 2 -reduction, as described above.
  • the codeposited metals are preferably alloyed by heating in an inert atmosphere. This heating step can also bring about the desired increase in occurrence of (111) and (110) faces, particularly (111) faces.
  • the alloyed crystals presumably cubo-octahedral in shape and containing both Pt and Au atoms
  • any sintering or heating steps which result in the formation of polycrystalline metal should be avoided as much as possible.
  • the co-deposition or seriatim deposition of platinum and gold salts on a support material followed by reduction can result in intimate mixtures which are macroscopically homogeneous, but are not preferred as "alloys" in the context of this invention.
  • At least some amount of heating e.g. to sintering temperatures or higher
  • methanol oxidation catalysts both to achieve microscopic homogeneity and to bring the supported metal particles into the optimum size range for (111) faceting, e.g. above 4 nm but less than 15 nm, preferably less than 10 nm.
  • the particle size increases beyond 5 nm, the risk of forming polycrystalline particles, e.g.
  • the Pt/Au combination can be formed by any of these techniques, including co-deposition or seriatim deposition, alloying, or heterogeneous mixing. In the case of heterogeneous mixing, it is not essential that the platinum gold particles be the same size.
  • the gold particles should be in the size range favoring (111) faces or faceting, but the platinum particles can be smaller or larger, if desired.
  • At least three approaches can be used: (1) co-deposition (including colloidal or electro ⁇ chemical) , (2) gold followed by platinum, and (3) platinum followed by gold.
  • the intimate mixture which is suitable for alloying and particle enlargement is obtained by electrochemical co-deposition of gold and platinum (simultaneously or seriatim) , most preferably by pulsed-current electrodeposition techniques.
  • pulse current electrodeposition Specific advantages offered by pulse current electrodeposition are: first, one can select a pulse waveform which provides high instantaneous current densities. High instantaneous current densities can help to control nucleation density and hence electrocatalyst dispersion.
  • control over the on-time of the pulse current provides control over the growth of the nuclei (tiny, dispersed electrodeposits smaller than 40A) and thereby influence the particle size of the electrocatalyst deposits (prior to particle enlargement) .
  • the scientific literature suggests that electro- deposited alloys have beneficial properties not necessarily obtained by other techniques for providing intimate metallic mixtures.
  • pulse current can provide control over the composition (%Au, %Pt, etc.) of the nuclei (deposits).
  • the pulse current electrodeposition technique can be used to maximize catalyst utilization.
  • the pulse current electrochemical deposition of noble metals on a conductive substrate as a technique for optimizing catalyst utilization, see Reddy et al, U.S. patent application Serial No. 07/560,206, filed July 31, 1990, the disclosure of which is incorporated herein by reference.
  • the carbon-supported catalyst material contain less than 20 wt.-% Pt, e.g. 10 wt.-% or less.
  • Catalyst loadings on the electrodes can be in the range of 0.05 to 2.0 mg/cm 2 of catalytic metal, preferably ⁇ 1.0 mg/cm 2 to save cost.
  • the electricity generation method of this invention can produce >40 mW/cm 2 of electrode or even >50 mW/cm 2 of electrode, and the anode/s.p.e./cathode system works well at temperatures well below 80*C, e.g. at ⁇ 65*C.
  • the "cold start" properties of an s.p.e. cell permit utilization of fuel cells exposed to ambient temperatures below 0*C, thereby opening up possibilities for use of this invention to power automobiles, buses, and trucks or lorries.
  • the polymers can be copolymers made from two, three, or even four different monomers. At least one of the monomers preferably is partially or fully fluorinated, contains at least one unsaturated site, and is provided with a pendant group terminated with an ionic or ionizable (e.g. acidic) radical. Particularly preferred monomers (and comono ers) include
  • CF(R f ) CFR f
  • Z is an acidic radical (e.g. -SO3H, -P0 3 H 2 , -COOH, -B(R f )OH, -P(R f )0 2 H, -B(OR f )OH, etc.)
  • the Rf radicals which are the same or different, are F, lower (C ⁇ ⁇ -Cg) perfluoroalkyl, or, less preferably, Cl, and n and m are numbers from 1 to 10.
  • the electrolyte is liquid rather than solid, it can be an organic solution, e.g. a solution of ion-exchange polymer, as in U.S. Patent 4,433,082 (Grot), issued February 21, 1984, or, preferably, an aqueous electrolyte such as an aqueous mineral acid, e.g. phosphoric, sulfuric, or perchloric acid or the like.
  • the lower alcohol "fuel” methanol, ethanol, etc.
  • the preferred alcohol fuel is methanol, but ethanol is also of interest because of its lower toxicity and availability from biomass sources.
  • Carbon dioxide produced from a biomass source does not contribute to the so-called "greenhouse effect", since one is simply returning to the atmosphere a quantity of C0 2 which had been recently extracted from it by plant matter.
  • Other lower primary alcohols e.g.1-propanol, 1-butanol, and n-amyl alcohol
  • Methanol Electro-Oxidation on Various Gold Surfaces The following data illustrate an important principle of this invention.
  • methanol was dissolved in 1.0M sulfuric acid to obtain a 0.5M methanol solution.
  • the cyclic voltammetry rotating disk electrodes used were provided with single-crystal Au (100), Au (110) and Au (111) as well as polycrystalline Au. Potential sweep rate and electrode rotation rate were 100 mV/sec and 2500 rp , respectively. All measurements were made at room temperature (23*C) . Results with smooth gold and single crystal gold were compared to results with Pt.

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Abstract

Dans ce procédé, un alcool inférieur est directement oxydé (c'est-à-dire sans reformage) en CO2+H2O à l'anode d'une pile à combustible, et un gaz réductible (par exemple de l'air ou O2) est réduit à la cathode. On peut obtenir des densités de courant raisonnablement continu élevées à des surtensions basses. L'électrolyte est de préférence un électrolyte de polymère solide acide, et l'anode comprend, comme électrocatalyseur, une combinaison d'un métal noble du groupe VIII avec de l'or ayant un caractactère Au (11) significatif. On a découvert que la face (111) de cristaux d'or (de préférence des cristaux dont la moyenne de taille se situe entre environ 4 et 15 nm) est spécifique pour permettre l'oxydation de produits d'oxydation d'alcool intermédiaire (CO, CHO, COH, HCH, CH3CHO etc) en CO2 ou CO2+H2O. Ainsi, la combinaison d'un métal du groupe VIII tel que Pt avec Au (111) évite l''empoisonnement' du Pt par ces produits intermédiaires. Une protection contre ledit 'empoisonnement' est également fournie par l'Au (110), mais l'Au (100) et l'or polycristallin ne sont pas considérés comme étant utiles dans l'électro-oxydation d'alcools inférieurs (notamment le méthanol et l'éthanol). Si le 'combustible' à l'alcool est du méthanol, la combinaison d'un métal noble du groupe VIII et de Au (111) doit être, à échelle microscopique, homogène (c'est-à-dire des cristaux cubo-octaédriques Pt/Au d'un niveau élevé de facettage (111)), mais si le 'combustible' est de l'éthanol, on peut combiner le métal noble du groupe VIII et le Au (111) de diverses manières, parmi lesquelles des mélanges homogènes macroscopiques et des associations hétérogènes.
PCT/US1991/005611 1990-08-08 1991-08-07 Production d'electricite a l'aide d'une pile a combustible utilisant un combustible a l'alcool WO1992002965A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US56437990A 1990-08-08 1990-08-08
US564,379 1990-08-08
US07/665,789 US5132193A (en) 1990-08-08 1991-03-07 Generation of electricity with fuel cell using alcohol fuel
US665,789 1991-03-07

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0557674A1 (fr) * 1990-09-29 1993-09-01 Tanaka Kikinzoku Kogyo K.K. Catalyseur à base d'alliage de platine et procédé pour le préparer
EP0684469A2 (fr) * 1994-05-24 1995-11-29 Siemens Aktiengesellschaft Appareil pour déterminer la concentration des alcools
EP0736921A1 (fr) * 1995-04-05 1996-10-09 Johnson Matthey Public Limited Company Electrode à deux électrocatalyseurs
EP1414089A1 (fr) * 2002-10-25 2004-04-28 National Institute of Advanced Industrial Science and Technology Pile à combustible avec catalyseur à l'or

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109353248A (zh) * 2018-10-15 2019-02-19 北汽福田汽车股份有限公司 燃料电池汽车的低温启动方法和系统

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3500494A (en) * 1967-10-19 1970-03-17 American Meat Packing Corp Automatic releasing mechanism
US3701687A (en) * 1968-08-29 1972-10-31 Gen Electric Electrode containing a catalytic coating of platinum,palladium,and a third metal and fuel cell utilizing same
US4390603A (en) * 1981-06-30 1983-06-28 Hitachi, Ltd. Methanol fuel cell
US4478917A (en) * 1982-03-26 1984-10-23 Hitachi, Ltd. Fuel cell
US4828941A (en) * 1986-06-04 1989-05-09 Basf Aktiengesellschaft Methanol/air fuel cells

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3500494A (en) * 1967-10-19 1970-03-17 American Meat Packing Corp Automatic releasing mechanism
US3701687A (en) * 1968-08-29 1972-10-31 Gen Electric Electrode containing a catalytic coating of platinum,palladium,and a third metal and fuel cell utilizing same
US4390603A (en) * 1981-06-30 1983-06-28 Hitachi, Ltd. Methanol fuel cell
US4478917A (en) * 1982-03-26 1984-10-23 Hitachi, Ltd. Fuel cell
US4828941A (en) * 1986-06-04 1989-05-09 Basf Aktiengesellschaft Methanol/air fuel cells

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0557674A1 (fr) * 1990-09-29 1993-09-01 Tanaka Kikinzoku Kogyo K.K. Catalyseur à base d'alliage de platine et procédé pour le préparer
EP0684469A2 (fr) * 1994-05-24 1995-11-29 Siemens Aktiengesellschaft Appareil pour déterminer la concentration des alcools
EP0684469A3 (fr) * 1994-05-24 1996-11-20 Siemens Ag Appareil pour déterminer la concentration des alcools.
EP0736921A1 (fr) * 1995-04-05 1996-10-09 Johnson Matthey Public Limited Company Electrode à deux électrocatalyseurs
US5795669A (en) * 1995-04-05 1998-08-18 Johnson Matthey Public Limited Company Electrode
EP1414089A1 (fr) * 2002-10-25 2004-04-28 National Institute of Advanced Industrial Science and Technology Pile à combustible avec catalyseur à l'or

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