Process for preparing electrodes using precious metal-catalyst containing partially fluorinated active carbon

{
  "publication_number": "US4431567A",
  "country": "US",
  "kind": "A",
  "title": "Process for preparing electrodes using precious metal-catalyst containing partially fluorinated active carbon",
  "abstract": "This disclosure is directed to preparing deashed, precious metal catalyst-containing, partially fluorinated active carbon particles of the formula CF x, where x ranges from 0.l to about 0.18, preferably using either platinum or silver as the catalyzing material, which can be incorporated into an active layer component of a gas electrode, e.g., an oxygen (air) cathode suitable for use in a chlor-alkali electrolytic cell for producing chlorine and caustic while conserving electrical energy. These particles are deashed to have a B.E.T. surface area of at least 600 m 2 /g and contain less than about 4 weight percent ash. Active electrode layers containing such particles demonstrate an unusually desirable combination of resistance to corrosion, retention of conductive properties and retention of catalytic surface area.",
  "claims": [
    "1. A method of preparing active carbon catalyst particles comprising depositing precious metal catalyst on partially fluorinated active carbon particles of the formula CF x, where x=0.1 to about 0.18, and having an ash content of less than about 4 weight percent and a B.E.T. surface area of at least 600 m 2 /g and discontinuously coating said partially fluorinated active carbon particles with smaller adherent polytetrafluoroethylene particles.",
    "2. A method as in claim 1 wherein said precious metal is platinum.",
    "3. A method as in claim 1 wherein said precious metal is silver.",
    "4. A method for preparing an electrode active layer comprising depositing a precious metal catalyst on partially fluorinated active carbon particles of the formula CF x, where x=0.1 to about 0.18 and having an ash content of less than about 4 weight percent and a B.E.T. surface area of at least 600 m 2 /g, discontinuously coating said particles with smaller adherent polytetrafluoroethylene particles, and combining said discontinuously coated particles with an intimate mix of carbon black particles and polytetrafluoroethylene particles and particulate pore-forming agent, and forming said mix into a sheet.",
    "5. A process as in claim 4 wherein said precious metal is platinum.",
    "6. A process as in claim 4 wherein said precious metal is silver.",
    "7. A process as in claim 4 wherein said active carbon particles have a particle size ranging from about 5 to about 20 microns.",
    "8. A process as in claim 4 wherein said carbon black is acetylene carbon black.",
    "9. A process as in claim 4 wherein said pore-former is a soluble pore-former.",
    "10. A process as in claim 9 wherein said pore-former is sodium carbonate.",
    "11. A process as in claim 4 wherein said pore-former is a volatile pore-former.",
    "12. A process as in claim 11 wherein said pore-former is ammonium benzoate."
  ],
  "cpc": [
    "H01M 4/8875",
    "B01J 27/12",
    "B01J 31/06",
    "B01J 33/00",
    "C01B 32/00",
    "C01P 2006/12",
    "C09C 1/56",
    "C25B 11/095",
    "H01M 4/8663",
    "H01M 4/8668",
    "H01M 4/92",
    "Y02E 60/50"
  ],
  "assignees": [
    "DIAMOND SHAMROCK CORP"
  ],
  "filing_date": "1982-02-22",
  "publication_date": "1984-02-14",
  "grant_date": "1984-02-14",
  "priority_date": "1980-10-31",
  "application_number": "US-35126582-A",
  "family_id": "26897826",
  "citations": [
    "US3356532A",
    "US3385780A",
    "US3409472A",
    "US3935029A",
    "US4135995A",
    "US4166143A",
    "US4187350A",
    "US4299682A"
  ]
}