WO1987005445A1 - Electrode for oxidising methanol - Google Patents

Electrode for oxidising methanol Download PDF

Info

Publication number
WO1987005445A1
WO1987005445A1 PCT/GB1987/000138 GB8700138W WO8705445A1 WO 1987005445 A1 WO1987005445 A1 WO 1987005445A1 GB 8700138 W GB8700138 W GB 8700138W WO 8705445 A1 WO8705445 A1 WO 8705445A1
Authority
WO
WIPO (PCT)
Prior art keywords
electrode
carbon
electrode according
substrate
catalyst
Prior art date
Application number
PCT/GB1987/000138
Other languages
French (fr)
Inventor
John Bannister Goodenough
Andrew Hamnett
Ramasamy Manoharan
Brendan James Kennedy
Original Assignee
National Research Development Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB868604982A external-priority patent/GB8604982D0/en
Priority claimed from GB868622455A external-priority patent/GB8622455D0/en
Application filed by National Research Development Corporation filed Critical National Research Development Corporation
Publication of WO1987005445A1 publication Critical patent/WO1987005445A1/en

Links

Classifications

    • 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
    • H01M4/9016—Oxides, hydroxides or oxygenated metallic salts
    • 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
    • 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
    • H01M4/925—Metals of platinum group supported on carriers, e.g. powder carriers
    • H01M4/926—Metals of platinum group supported on carriers, e.g. powder carriers on carbon or graphite
    • 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
    • H01M4/96—Carbon-based electrodes
    • 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
    • H01M2300/0005—Acid 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
    • H01M2300/0011—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
    • H01M2300/0002—Aqueous electrolytes
    • H01M2300/0014—Alkaline electrolytes
    • 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
    • H01M4/921—Alloys or mixtures with metallic elements
    • 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

  • an electrode for oxidising methanol comprises a preferably porous substrate which is an electronic conductor capable of reducing elemental oxygen to water yielding not more than 5% (preferably not more than 1%, more preferably not more than 0.1%) hydrogen peroxide, to which substrate is attached a catalyst comprising platinum and either or both of ruthenium and titanium dioxide.
  • a preferred suitable substrate is carbon of an ash content less than 0.1%, preferably less than 0.05%, preferably not more than 0.01%.
  • An example of such a carbon is 'coconut carbon', which is derived from coconut shells by converting these to charcoal, washing and comminuting the charcoal, and exposing the comminuted charcoal to gas, preferably first carbon dioxide and optionally afterwards ammonia or the latter by itself.
  • An alternative suitable gas is steam.
  • carbon for example sold by Cabot Corporation under the Trade Mark
  • Vulcan XC-72 which is of poorly crystalline type and has a surface area of at least 200 m 2 /g, a mean particle size in the range 5 nm to 50 nm, and an apparent density of 80 to 110 kg/m 3 , which may be treated by comminuting it and exposing it to gas at elevated temperature.
  • the carbon before the comminution has a surface area of not more than 300 m 2 /g.
  • the carbon before the comminution has a pH below 7.
  • the carbon may be exposed to only carbon dioxide, for example at 800oC to 1000oC, preferably for 40 to 90 minutes, such as 900oC for 1 hour.
  • Catalyst loadings may be 1 to 15% by weight of the substrate, preferably 2 to 12%.
  • the invention extends to a fuel cell including an electrode as set forth above.
  • the invention also provides a method of oxidising methanol, comprising contacting methanol and water at an electrode as set forth above and applying to the electrode a potential more positive than -0.3 volts with respect to the Hg/Hg 2 SO 4 electrode.
  • the invention provides a method of making an electrode as set forth above, comprising applying a solution containing a platinum and a ruthenium compound onto the substrate and decomposing the compounds, whereby the desired catalyst is precipitated on, and is attached to, the substrate.
  • the substrate is mixed with a titanium compound which is decomposed to form titanium dioxide.
  • the invention extends to the electrode so made, and to fuel cells, methods of oxidising methanol etc. using it.
  • the 'coconut' carbon is preferred.
  • the poorly crystalline carbon is preferred.
  • Figures 1 and 2 show the potential versus current density obtained for various electrodes in 2.5M H 2 SO 4 , 1M MeOH.
  • Figure 3 shows the specific activities for some of these electrodes.
  • Figure 4 shows lifetime data.
  • a porous carbon electrode is made utilising Vulcan XC-72 carbon.
  • High-surface-area Vulcan XC-72 carbon was obtained from the Cabot Corp., Billerica, MA. The ash content of this carbon was found to be about 0.05%. The other physical and chemical parameters of this carbon are as follows:
  • Platinum has been dispersed into the gas-activated carbon by reducing chloroplatinic acid with sodium formate solution as described elsewhere. This procedure (yielding comparative electrodes) yields fine platinum particles of uniform size (about 63A diameter) on a carbon substrate.
  • Chloroplatinic acid solution containing the required proportion of platinum was taken from a 2 weight % stock solution, mixed with half of its volume of isopropanol, and neutralised with a dilute solution of sodium carbonate.
  • An appropriate quantity of gas-activated Vulcan XC-72 carbon was added, and the entire mixture was dried in an air oven before it was added, with vigorous stirring, to an excess of boiling 5 weight % sodium formate solution to reduce the chloroplatinic acid to platinum metal.
  • the resulting mass was filtered and washed repeatedly with hot, distilled water before being dried in an air oven.
  • a supported Pt-Ru- catalyst was prepared by co-impregnation of the gas-activated Vulcan XC-72 carbon with a mixed solution containing appropriate amounts of chloroplatinic acid H 2 PtCl 6 and ruthenium trichloride RuCl 3 .
  • the impregnated carbon was evaporated to dryness and reduced at 200oC for 20 hours in flowing H 2 .
  • Teflon-bonded electrodes were prepared for electrochemical measurements.
  • the Teflon binder provides the necessary mechanical strength to prevent electrode collapse under the gas pressure required for gas-electrolyte interface control in a gas-diffusion electrode, and it does so while retaining the necessary electrode porosity.
  • the Teflon-bonded electrodes were made as follows: Tetrahydrofuran (THF) was added to a measured quantity of catalysed substrate powder in a beaker, and the mixture was agitated in an ultrasonic bath for about 30 minutes before a few ml of dilute suspension of Teflon emulsion (ICI GP2 Fluon dispersion, particle size 0.1-0.2 microns) was added to the mixture without interruption of the agitation.
  • THF Tetrahydrofuran
  • the product material was centrifuged repeatedly with THF and finally spread on a platinum expanded-metal (Exmet) screen (0.076 mm diameter wire, 1024 mesh cm -2 ).
  • the coated screen was air-dried for about 15 minutes before it was cold-pressed at 125 kg cm -2 for 5 minutes.
  • the pressed mass was dried for 2 hours at 110oC and then cured in air at 360oC for 30 minutes.
  • the -Teflon content of the electrodes was optimal at 25 to 35% by volume, the content in each case being 30% unless otherwise stated on the Figure.
  • the platinum loading was 3% on Figure 1 and 5% on Figure 2.
  • the BET surface area of such a substrate was about 600 m 2 /g and the resistivity about 0.4 ohm cm.
  • Comparative Pt-Ru electrodes have been made by compressing Pt-Ru alloy onto a platinum mesh at a pressure of 1.7 tonne cm -2 .
  • An electrochemical cell for measuring electrochemical performance parameters was set up containing this substrate as a working electrode, a Hg/Hg 2 So 4 , H + reference electrode, a high surface area flatbed counter electrode, and an electrolyte, which was a solution of 2.5M sulphuric acid H 2 SO 4 and 1M methanol CH 3 OH in distilled water.
  • a platinum/titanium dioxide/treated carbon electrode was made as follows. 400 mg of gas treated Vulcan XC-72 was suspended in 100 ml of water and heated to boiling. A dilute solution of titanium (IV) isoproproxide in isopropanol was slowly added and the solution boiled for 1 hour. The pH was then adjusted to 12 with NH 3 OH. A 2% chloroplatinic acid solution was then added and after a further hour the solution brought to dryness. The resulting solid was dried at 110 for 12 hours, re-suspended in water and a five-fold excess of HCOONa added. The mixture was then boiled for 2 hours, filtered, washed with boiling distilled water and dried at 110°. The electrode was made as described previously for platinised carbon electrodes and had the composition: Pt-7%, TiO 2 -3%, C t -63%, Teflon 27%. EXAMPLE 3
  • a platinum/ruthenium/titanium dioxide/treated carbon electrode was made as follows. 600 mg of gas treated Vulcan XC-72 was suspended in 100 ml of water and heated to boiling. A dilute solution of Titanium (IV) isopropoxide in isopropanol was slowly added followed by 2% solutions of chloroplatanic acid and ruthenium trichloride in water. The resulting solution was neutralised with a dilute solution of sodium hydrogen carbonate. The slurry was brought to dryness, dried at 110 for 12 hours, re-suspended in water, reduced with HCOONa, filtered, washed with water and finally dried as above.

Abstract

An electrode for oxidising methanol comprises a preferably porous substrate which is an electronic conductor capable of reducing elemental oxygen to water yielding not more than 5% hydrogen peroxide, to which substrate is attached a catalyst comprising platinum and ruthenium, or platinum and titanium dioxide, or all three.

Description

ELECTRODE FOR OXIDISING METHANOL This invention relates to an electrode for oxidising methanol, to a fuel cell including such an electrode, to a method of oxidising methanol at such an electrode, and to a method of making certain such electrodes. According to the present Invention, an electrode for oxidising methanol comprises a preferably porous substrate which is an electronic conductor capable of reducing elemental oxygen to water yielding not more than 5% (preferably not more than 1%, more preferably not more than 0.1%) hydrogen peroxide, to which substrate is attached a catalyst comprising platinum and either or both of ruthenium and titanium dioxide.
A preferred suitable substrate is carbon of an ash content less than 0.1%, preferably less than 0.05%, preferably not more than 0.01%. An example of such a carbon is 'coconut carbon', which is derived from coconut shells by converting these to charcoal, washing and comminuting the charcoal, and exposing the comminuted charcoal to gas, preferably first carbon dioxide and optionally afterwards ammonia or the latter by itself. An alternative suitable gas is steam. Another example is carbon (for example sold by Cabot Corporation under the Trade Mark
Vulcan XC-72) which is of poorly crystalline type and has a surface area of at least 200 m2/g, a mean particle size in the range 5 nm to 50 nm, and an apparent density of 80 to 110 kg/m3, which may be treated by comminuting it and exposing it to gas at elevated temperature. Preferably the carbon before the comminution has a surface area of not more than 300 m2/g. Preferably the carbon before the comminution has a pH below 7. The carbon may be exposed to only carbon dioxide, for example at 800ºC to 1000ºC, preferably for 40 to 90 minutes, such as 900ºC for 1 hour. Catalyst loadings may be 1 to 15% by weight of the substrate, preferably 2 to 12%. The invention extends to a fuel cell including an electrode as set forth above. The invention also provides a method of oxidising methanol, comprising contacting methanol and water at an electrode as set forth above and applying to the electrode a potential more positive than -0.3 volts with respect to the Hg/Hg2SO4 electrode.
According to another aspect, the invention provides a method of making an electrode as set forth above, comprising applying a solution containing a platinum and a ruthenium compound onto the substrate and decomposing the compounds, whereby the desired catalyst is precipitated on, and is attached to, the substrate. Preferably the substrate is mixed with a titanium compound which is decomposed to form titanium dioxide. The invention extends to the electrode so made, and to fuel cells, methods of oxidising methanol etc. using it. For use in alkaline media, the 'coconut' carbon is preferred. For use in acid media, the poorly crystalline carbon is preferred.
The invention will now be described by way of example. In the accompanying drawings, Figures 1 and 2 show the potential versus current density obtained for various electrodes in 2.5M H2SO4, 1M MeOH. Figure 3 shows the specific activities for some of these electrodes. Figure 4 shows lifetime data. In Figures 1 to 3, some electrodes not according to the invention are included for comparison. A porous carbon electrode is made utilising Vulcan XC-72 carbon.
High-surface-area Vulcan XC-72 carbon was obtained from the Cabot Corp., Billerica, MA. The ash content of this carbon was found to be about 0.05%. The other physical and chemical parameters of this carbon are as follows:
Surface area 257 m2/g
Mean particle size 30 nm
Approximate density 96 kg/m3 pH 5 This carbon was subjected to mechanical grinding and then gas-activated by heating in a CO2 atmosphere at 900ºC for 1 hour. Gas activation rather than continued grinding was chosen to minimise particle agglomeration; it produced a 27% weight loss of the carbon, increased the effective surface area, and modified the surface. Titanium dioxide is impregnated into the carbon by mixing an appropriate amount of titanium (IV) isopropoxide with the carbon and allowing it to hydrolyse in air.
Platinum has been dispersed into the gas-activated carbon by reducing chloroplatinic acid with sodium formate solution as described elsewhere. This procedure (yielding comparative electrodes) yields fine platinum particles of uniform size (about 63A diameter) on a carbon substrate. Chloroplatinic acid solution containing the required proportion of platinum was taken from a 2 weight % stock solution, mixed with half of its volume of isopropanol, and neutralised with a dilute solution of sodium carbonate. An appropriate quantity of gas-activated Vulcan XC-72 carbon was added, and the entire mixture was dried in an air oven before it was added, with vigorous stirring, to an excess of boiling 5 weight % sodium formate solution to reduce the chloroplatinic acid to platinum metal. The resulting mass was filtered and washed repeatedly with hot, distilled water before being dried in an air oven. EXAMPLE 1 Platinum and ruthenium are to be co-deposited, in the atomic ratio Pt:Ru= 7:3.
A supported Pt-Ru- catalyst was prepared by co-impregnation of the gas-activated Vulcan XC-72 carbon with a mixed solution containing appropriate amounts of chloroplatinic acid H2PtCl6 and ruthenium trichloride RuCl3. The impregnated carbon was evaporated to dryness and reduced at 200ºC for 20 hours in flowing H2.
Teflon-bonded electrodes were prepared for electrochemical measurements. The Teflon binder provides the necessary mechanical strength to prevent electrode collapse under the gas pressure required for gas-electrolyte interface control in a gas-diffusion electrode, and it does so while retaining the necessary electrode porosity. The Teflon-bonded electrodes were made as follows: Tetrahydrofuran (THF) was added to a measured quantity of catalysed substrate powder in a beaker, and the mixture was agitated in an ultrasonic bath for about 30 minutes before a few ml of dilute suspension of Teflon emulsion (ICI GP2 Fluon dispersion, particle size 0.1-0.2 microns) was added to the mixture without interruption of the agitation. The product material was centrifuged repeatedly with THF and finally spread on a platinum expanded-metal (Exmet) screen (0.076 mm diameter wire, 1024 mesh cm-2). The coated screen was air-dried for about 15 minutes before it was cold-pressed at 125 kg cm-2 for 5 minutes. The pressed mass was dried for 2 hours at 110ºC and then cured in air at 360ºC for 30 minutes. The -Teflon content of the electrodes was optimal at 25 to 35% by volume, the content in each case being 30% unless otherwise stated on the Figure. The platinum loading was 3% on Figure 1 and 5% on Figure 2. The BET surface area of such a substrate was about 600 m2/g and the resistivity about 0.4 ohm cm.
Comparative Pt-Ru electrodes have been made by compressing Pt-Ru alloy onto a platinum mesh at a pressure of 1.7 tonne cm-2. An electrochemical cell for measuring electrochemical performance parameters was set up containing this substrate as a working electrode, a Hg/Hg2So4, H+ reference electrode, a high surface area flatbed counter electrode, and an electrolyte, which was a solution of 2.5M sulphuric acid H2SO4 and 1M methanol CH3OH in distilled water.
Platinum-black electrodes and platinum dispersed on normal carbon electrodes are easily poisoned. However, if carbon is treated with C0„ at 900ºC, and ruthenium is jointly dispersed with the platinum, good stability and performance are obtained, as may be seen from the Figures.
Interesting features of these figures are significant improvement in performance at higher electrolyte temperature, high current densities, decrease in the otherwise rapid rise in overpotential for the first few mA, and enhanced performance in terms of the electrode design. The poisoning mentioned above is tentatively believed to result from poisoning of platinum itself. This can be slowed, i.e. lifetime can be lengthened, by having fine dispersed platinum particles, hence the preference for in situ chemical formation of the platinum on the substrate. Meanwhile, the carbon treatment mentioned above gives, as shown, a useful decrease in overpotential. The combination of decrease in overpotential and longer life is valuable.
Comparison of current-potential curves with the curves of potential versus current per mg of platinum shows that significant reduction in cost is achieved by deposition of the Pt-Ru catalyst onto the activated carbon substrate. The service-life data for various electrodes are presented in
Figure 4. A power density of about 80 mW cm-2 could be achieved if one were to combine the methanol anode (Pt-Ru/Ct) and an oxygen reducing cathode. EXAMPLE 2
A platinum/titanium dioxide/treated carbon electrode was made as follows. 400 mg of gas treated Vulcan XC-72 was suspended in 100 ml of water and heated to boiling. A dilute solution of titanium (IV) isoproproxide in isopropanol was slowly added and the solution boiled for 1 hour. The pH was then adjusted to 12 with NH3OH. A 2% chloroplatinic acid solution was then added and after a further hour the solution brought to dryness. The resulting solid was dried at 110 for 12 hours, re-suspended in water and a five-fold excess of HCOONa added. The mixture was then boiled for 2 hours, filtered, washed with boiling distilled water and dried at 110°. The electrode was made as described previously for platinised carbon electrodes and had the composition: Pt-7%, TiO2-3%, Ct-63%, Teflon 27%. EXAMPLE 3
A platinum/ruthenium/titanium dioxide/treated carbon electrode was made as follows. 600 mg of gas treated Vulcan XC-72 was suspended in 100 ml of water and heated to boiling. A dilute solution of Titanium (IV) isopropoxide in isopropanol was slowly added followed by 2% solutions of chloroplatanic acid and ruthenium trichloride in water. The resulting solution was neutralised with a dilute solution of sodium hydrogen carbonate. The slurry was brought to dryness, dried at 110 for 12 hours, re-suspended in water, reduced with HCOONa, filtered, washed with water and finally dried as above.

Claims

1. An electrode for oxidising methanol, comprising a substrate which is an electronic conductor capable of reducing elemental oxygen to water yielding not more than 5% hydrogen peroxide, to which substrate is attached a catalyst comprising platinum and either one or both of titanium dioxide and ruthenium.
2. An electrode according to Claim 1, wherein the substrate is porous.
3. An electrode according to Claim 1 or 2, wherein the electronic conductor is capable of reducing elemental oxygen to water yielding not more than 1% hydrogen peroxide.
4. An electrode according to Claim 3, wherein the electronic conductor is capable of reducing elemental oxygen to water yielding not more than 0.1% hydrogen peroxide.
5. An electrode according to any preceding claim, wherein the catalyst comprises (i) Pt and Ru; or (ii) Pt and TiO2; or (iii) Pt and Ru- and TiO2.
6. An electrode according to any preceding claim, wherein the substrate is carbon of an ash content less than 0.1%.
7. An electrode according to Claim 6, wherein the carbon is 'coconut carbon', which is derived from coconut shells by converting these to charcoal, washing and comminuting the charcoal, and exposing the comminuted charcoal to gas,
8. An electrode according to Claim 7, wherein said gas to which the comminuted charcoal is exposed is carbon dioxide or is ammonia or is carbon dioxide followed by ammonia or is steam.
9. An electrode according to Claim 6, wherein the carbon is of poorly crystalline type and has a surface area of at least 200 m2/g, a mean particle size in the range 5 nm to 50 nm, and an apparent density of 80 to 110 kg/m3
10. An electrode according to Claim 9, wherein the carbon is treated by comminuting it and exposing it to gas at elevated temperature.
11. An electrode according to Claim 10, wherein the carbon before the comminution has a surface area of not more than 300 m2/g.
12. An electrode according to Claim 10 or 11, wherein the carbon before the comminution has a pH below 7.
13. An electrode according to any of Claims 10 to 12, wherein the carbon is exposed to only carbon dioxide.
14. An electrode according to Claim 13, wherein the exposure is for 40 to 90 minutes at 800°C to 1000°C.
15. An electrode according to any preceding claim, wherein the catalyst is present in a proportion of from 1 to 15% by weight of the substrate.
16. An electrode according to Claim 15, wherein the catalyst is present in a proportion of from 2 to 12% by weight of the substrate.
17. A method of making an electrode as claimed in any preceding claim, comprising applying a solution containing a platinum and a ruthenium compound onto the substrate and decomposing the compounds, whereby the desired catalyst is precipitated on, and is attached to, the substrate.
18. A method according to Claim 17, wherein the substrate is mixed with a titanium compound which is decomposed to form titanium dioxide.
19. A fuel cell wherein methanol is oxidised at an electrode, the electrode being as claimed in any of Claims 1 to 16 or having been made by a method according to Claim 17 or 18.
20. A method of oxidising methanol, comprising contacting methanol and water at an electrode as claimed in any of Claims 1 to 16 or having been made by a method according to Claim 17 or 18, and applying to the electrode a potential more positive than -0.3 volts with respect to the Hg/Hg2SO4 electrode.
PCT/GB1987/000138 1986-02-28 1987-02-26 Electrode for oxidising methanol WO1987005445A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GB8604982 1986-02-28
GB868604982A GB8604982D0 (en) 1986-02-28 1986-02-28 Electrode for oxidising methanol
GB868622455A GB8622455D0 (en) 1986-09-18 1986-09-18 Electrode
GB8622455 1986-09-18

Publications (1)

Publication Number Publication Date
WO1987005445A1 true WO1987005445A1 (en) 1987-09-11

Family

ID=26290416

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1987/000138 WO1987005445A1 (en) 1986-02-28 1987-02-26 Electrode for oxidising methanol

Country Status (3)

Country Link
EP (1) EP0259424A1 (en)
GB (1) GB2187880A (en)
WO (1) WO1987005445A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5795669A (en) * 1995-04-05 1998-08-18 Johnson Matthey Public Limited Company Electrode

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU546551A (en) * 1951-10-04 1951-12-06 Courtaulds Limited Improvements in and relating to apparatus for ageing alkali cellulose
US3212936A (en) * 1960-11-07 1965-10-19 Air Prod & Chem Method of forming paste-form fuel cell electrode
GB1163479A (en) * 1967-03-17 1969-09-04 Engelhard Min & Chem Fuel Electrodes
FR2166042A1 (en) * 1971-12-29 1973-08-10 Exxon Research Engineering Co
FR2261059A1 (en) * 1974-02-19 1975-09-12 Shell Int Research
FR2266956A1 (en) * 1974-04-08 1975-10-31 Exxon Research Engineering Co
US4028274A (en) * 1976-06-01 1977-06-07 United Technologies Corporation Support material for a noble metal catalyst and method for making the same
GB2067344A (en) * 1979-12-04 1981-07-22 Hitachi Ltd Liquid fuel cell
WO1986001642A1 (en) * 1984-09-06 1986-03-13 National Research Development Corporation Electrode for reducing oxygen

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2095025B (en) * 1981-03-17 1984-11-21 Hitachi Ltd Acid electrolyte fuel cell

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU546551A (en) * 1951-10-04 1951-12-06 Courtaulds Limited Improvements in and relating to apparatus for ageing alkali cellulose
US3212936A (en) * 1960-11-07 1965-10-19 Air Prod & Chem Method of forming paste-form fuel cell electrode
GB1163479A (en) * 1967-03-17 1969-09-04 Engelhard Min & Chem Fuel Electrodes
FR2166042A1 (en) * 1971-12-29 1973-08-10 Exxon Research Engineering Co
FR2261059A1 (en) * 1974-02-19 1975-09-12 Shell Int Research
FR2266956A1 (en) * 1974-04-08 1975-10-31 Exxon Research Engineering Co
US4028274A (en) * 1976-06-01 1977-06-07 United Technologies Corporation Support material for a noble metal catalyst and method for making the same
GB2067344A (en) * 1979-12-04 1981-07-22 Hitachi Ltd Liquid fuel cell
WO1986001642A1 (en) * 1984-09-06 1986-03-13 National Research Development Corporation Electrode for reducing oxygen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
CHEMICAL ABSTRACTS, Volume 72, No. 16, 20 April 1970, (Columbus, Ohio, US), ViI. GANTS et al.: "Relation Between the Catalytic and Electrochemical Activities of Carbon", see page 534, Abstract 85602g, & Zh. Prikl. Khim. (Leningrad) 1969, 42(11), 2489-93 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5795669A (en) * 1995-04-05 1998-08-18 Johnson Matthey Public Limited Company Electrode

Also Published As

Publication number Publication date
EP0259424A1 (en) 1988-03-16
GB8704526D0 (en) 1987-04-01
GB2187880A (en) 1987-09-16

Similar Documents

Publication Publication Date Title
US4354958A (en) Fibrillated matrix active layer for an electrode
US4456521A (en) Three layer laminate
US4518705A (en) Three layer laminate
US4500647A (en) Three layer laminated matrix electrode
US4379772A (en) Method for forming an electrode active layer or sheet
KR100751654B1 (en) Gas diffusion electrodes containing modified carbon products
Goodenough et al. Porous carbon anodes for the direct methanol fuel cell—I. The role of the reduction method for carbon supported platinum electrodes
KR100772257B1 (en) Modified carbon products useful in gas diffusion electrodes
US4716087A (en) Platinum-copper alloy electrocatalyst and acid-electrolyte fuel cell electrode using the same
CN101583420B (en) Porous clusters of silver powder promoted by zirconium oxide for use as a catalyst in gas diffusion electrodes, and method for the production thereof
US4370284A (en) Non-bleeding electrode
EP1169743B1 (en) Gas difffusion substrates
US4440617A (en) Non-bleeding electrode
CN1317158A (en) Electrochemical oxidation of hydrogen sulfide
EP1773488A2 (en) Catalyst support for an electrochemical fuel cell
Ralbag et al. Composite materials with combined electronic and ionic properties
US4431567A (en) Process for preparing electrodes using precious metal-catalyst containing partially fluorinated active carbon
KR20160131217A (en) Complex catalyst for metal air battery, method for preparing the same, positive electrode for metal air battery comprising the same, and method for preparing the positive electrode
US4337139A (en) Fluorinated carbon electrode
de la Fuente et al. Enhanced methanol electrooxidation activity of PtRu nanoparticles supported on H2O2-functionalized carbon black
CA1208168A (en) Producing electrode active layer from active carbon particles and fibrillated polytetrafluoroethylene
US4377496A (en) Gas diffusion electrode and process
WO1987005445A1 (en) Electrode for oxidising methanol
KR100965836B1 (en) Method for preparing metal catalyst comprising fluorine functionalized carbon support
GB2164785A (en) Electrode for reducing oxygen

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): DE FR SE