Science Buddies: "Ask an Expert"

In the diagram in the background section, show that the hydrogen comes in one tube, getting trapped in the annode. The Electrolyte helps trap the positive ions while the negative ones are passed through a wire at the top generating energy. When the Hydrogen posotive and negative ions meet at the cathode, and link with oxygen atoms, water is created as a waste. This was my understanding of the PEMFC. When I went to the procedure, there was no place for hydrogen or oxygen to go too. I remember learning about reverse electrolysis where a current was created when linking hydrogen and oxygen molecules. Is that how the project works? Because in the diagram that was shown in the background section it talked about the hydrogen and oxyegen molecules linking together to create water as a waste product (water) but in the procedure it seems different. I was hoping someone could further explain to me how the fuel cell being made in this project works. thanks!


[Administrator: project: https://www.sciencebuddies.org/science- ... fuel-cells ]

Hi AanyaB,

Fuel cells work by using hydrogen and oxygen to create energy, and water is the byproduct of the reaction to create the energy. The hydrogen gas reacts with the catalyst layer to produce positive hydrogen ions (H+) and electrons (e-). The electrons are not negative hydrogen though. The electrons produce the electrical current when they move out of the fuel cell and can be used as power. On the cathode side, oxygen reacts with the hydrogen ions produced in the previous reaction and the electrons returned to fuel cell. This latter reaction produces water.

This link has a pretty good description of how fuel cells work:
https://auto.howstuffworks.com/fuel-eff ... l-cell.htm

This YouTube video also describes how fuel cells work with a nice illustration (0:50):
https://www.youtube.com/watch?v=5_lDGna ... lEducation

There are many other YouTube videos with illustrations of fuel cell concepts. This one is also particularly good:
https://www.youtube.com/watch?v=MQG87a8 ... ydrogenHub

Hope this helps!
Dr. Payne

Thanks again for all your help!