{
  "patent_number": "US 4253922",
  "country": "US",
  "title": "How a Special Carbon-Fluorine Catalyst Makes Chlorine and Caustic Soda",
  "original_title": "Cathode electrocatalysts for solid polymer electrolyte chlor-alkali cells",
  "summary": "This patent describes using a unique carbon-fluorine compound as a catalyst in a special type of electrolysis cell to make chlorine and caustic soda more efficiently by preventing hydrogen gas from forming.",
  "what_it_does": "The patent improves the chlor-alkali process, which creates chlorine and sodium hydroxide (caustic soda) from salt water. Instead of a traditional cathode that produces hydrogen gas, this invention uses a \"solid polymer electrolyte\" cell (Claim 1). The key improvement involves placing a specific catalyst, an \"intercalation compound of carbon and fluorine\" (Claim 1, 8), on the cathode side. An \"oxidant,\" such as oxygen (Claim 5), is fed to this side. This setup \"substantially eliminates hydrogen evolution\" (Claim 1), meaning less hydrogen gas is made, which saves energy. For example, a cell could use this carbon-fluorine catalyst (like CFx where x is between 0.25 and 1.0, Claim 6) to convert oxygen and water into hydroxide ions, boosting efficiency.",
  "what_it_does_not_cover": [
    "Electrolysis cells that produce hydrogen gas at the cathode as the primary cathodic reaction.",
    "Cathode depolarization methods that do not use an \"intercalation compound of carbon and fluorine\" as the catalyst.",
    "Chlor-alkali processes that do not use a solid polymer electrolyte to separate the anolyte and catholyte compartments.",
    "Cathodes that do not receive an external oxidant feed to prevent hydrogen evolution.",
    "Catalysts that are not specifically carbon-fluorine intercalation compounds, or the specific oxidant complexes mentioned in claim 11."
  ],
  "filed": "1979-02-23",
  "granted": "1981-03-03",
  "expires": "1999-02-23",
  "status": "expired",
  "holder": "PPG Industries",
  "holder_url": "https://patentbrief.org/company/ppg-industries",
  "inventors": [
    {
      "name": "Cletus N. Welch",
      "url": "https://patentbrief.org/inventor/cletus-n-welch"
    }
  ],
  "times_cited": 47,
  "tags": [
    "chemical",
    "energy",
    "manufacturing",
    "materials",
    "industrial_process",
    "electrochemistry"
  ],
  "abstract": "Disclosed herein is a method of preparing porous transition metal catalysts for a solid polymer electrolyte electrolytic cell. Also disclosed is the use of solid carriers for carrying oxidant to a depolarized solid polymer electrolyte cell. Finally, there is disclosed the use of an intercalation compound of carbon and fluorine as the cathode catalyst.",
  "url": "https://patentbrief.org/patent/us/4253922/cathode-electrocatalysts-for-solid-polymer-electrolyte-chlor-alkali-cells",
  "markdown_url": "https://patentbrief.org/patent/us/4253922/cathode-electrocatalysts-for-solid-polymer-electrolyte-chlor-alkali-cells/md",
  "google_patents_url": "https://patents.google.com/patent/US4253922",
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}