(Photo Credit: Elsie esq)
Combustion reactions are only one means of extracting useful energy from fuels. Over the years, scientists all over the world have explored the possibility of converting the chemical energy of fuels directly to electricity.
They call this new possibility as “Fuel Cell” – A chemical cell in which reactants (usually a fuel and oxygen) are continuously supplied to produce electricity directly.
The most common type of fuel cell is the Hydrogen-Oxygen Fuel Cell which is used as a source of electrical power in many spaceships and vehicles.
A Hydrogen-Oxygen Fuel Cell is indeed a Chemical Cell and consists of 2 electrodes – a positive electrode (Cathode) and a negative electrode (Anode).
At the Cathode: O2(g) + 2H2O(l) + 4e– –> 4OH–(aq)
At the Anode: 2H2(g) + 4OH–(aq) –> 4H2O(l) + 4e–
Overall reaction: O2(g) + 2H2(g) –> 2H2O(l)
As you can see from the overall reaction, it involves the conversion of hydrogen and oxygen gas to water. This is similar to Combustion of Hydrogen.
Now, a very quick question for you.
What is the advantage (s) of using a Hydrogen-Oxygen Fuel Cell?
PS: I would love to hear from you. Cheers!