Fuel Cells

• What is a fuel cell?

  A type of electrochemical cell
• What do fuel cells convert energy between?

  Electrical and chemical forms
• What chemical reaction occurs in a hydrogen oxygen fuel cell?

  Combines hydrogen and oxygen to form water
• What is the most common type of fuel cell?

  Hydrogen oxygen fuel cell
• 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
  • Connected by a wire for electron flow
  • 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
• What happens to hydrogen at the anode?

  It is oxidized and loses electrons
• What do electrons do after hydrogen is oxidized?

  They flow to the cathode
• What do hydrogen ions do after being produced?

  They move through the electrolyte to the cathode
• How many hydrogen ions and electrons are needed to react with one oxygen molecule?

  Four hydrogen ions and four electrons
• What is produced at the cathode during the reaction?

  Two molecules of water
• What are half equations in the context of fuel cells?

  They show the loss or gain of electrons
• What is the overall equation for the reaction in a fuel cell?

  Combines hydrogen and oxygen to make water
• What drives the movement of electrons 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
  • Hydrogen is explosive when mixed with air
  • Producing hydrogen fuel requires energy, often from fossil fuels
• What is the main idea behind using fuel cells?

  To replace fossil fuel engines and batteries
• What is a significant environmental benefit of fuel cells?

  They do not produce carbon dioxide
• Why are fuel cells considered simpler devices than batteries?

  They last longer and are easier to dispose of
• What is the main problem with hydrogen fuel production?

  It often requires energy from fossil fuels