Fuel cells

• What is a fuel cell?

  A type of electrochemical cell converting energy
• What do fuel cells convert chemical energy into?

  Electrical energy to power devices
• What is the most common type of fuel cell?

  Hydrogen oxygen fuel cell
• What do hydrogen and oxygen combine to form in a fuel cell?

  Water while generating electrical energy
• What is the structure of a hydrogen oxygen fuel cell?

  • Central electrolyte (common: potassium hydroxide)
  • Negative anode on the left
  • Positive cathode on the right
  • Wire connecting anode and cathode
  • Porous carbon electrodes with catalysts
  • Inlets for hydrogen and oxygen
  • Outlet for water and heat
• What is the role of the electrolyte in a fuel cell?

  It allows ions to move through
• What is the charge of the anode in a fuel cell?

  Negative
• What is the charge of the cathode in a fuel cell?

  Positive
• How do electrons flow in a fuel cell?

  From the anode to the cathode through a wire
• What happens to hydrogen atoms at the anode?

  They lose electrons and become hydrogen ions
• What do hydrogen ions do after being formed?

  Move through the electrolyte to the cathode
• What do electrons react with at the cathode?

  Oxygen that comes in from the right
• How many hydrogen ions and electrons are needed for each oxygen molecule?

  Four hydrogen ions and four electrons
• What is produced when hydrogen ions and electrons react with oxygen?

  Two molecules of water
• What do the half equations in fuel cells represent?

  The oxidation of hydrogen and reduction of oxygen
• What does the overall equation of the fuel cell reaction show?

  Combining oxygen and hydrogen to make water
• What drives the electrons around the circuit in a fuel cell?

  The potential difference across the cell
• What are the pros of hydrogen oxygen fuel cells?

  • Only require hydrogen and oxygen
  • No carbon dioxide or pollutants produced
  • Longer lifespan than batteries
  • Less polluting to dispose of
• What are the cons of hydrogen oxygen fuel cells?

  • Hydrogen is a gas, requiring more storage space
  • Explosive when mixed with air
  • Hydrogen production often relies on fossil fuels
• What is the main idea behind using fuel cells?

  To replace fossil fuel engines and batteries
• Why are hydrogen oxygen fuel cells considered less polluting?

  They do not produce carbon dioxide as waste
• How does the storage of hydrogen compare to fossil fuels?

  Hydrogen takes up more space than fossil fuels
• What is a significant risk associated with hydrogen storage?

  It is explosive when mixed with air
• What is a major issue with hydrogen production?

  It often requires energy from fossil fuels