Fuel Cells

Fuel Cells

Fuel cells are cells in which there is a continual supply of reactants and thus creates a continual amount of energy. This energy is made via spontaneous redox reactions just like galvanic cells.

Oxygen is always a reactant at the cathode for all fuel cell reactions; oxygen is always being reduced. The type of reductant used determines what type of fuel cell it is. For example, the use of OH- or methanol as reactants are for alkaline fuel cells and methanol fuel cells respectively. A simple fuel cell which uses oxygen and hydrogen as its reactants is shown below.

H_{ 2 }(g)+2OH^{ - }(aq)\rightarrow2H_{2}O(l)+2e^{-} O_{2}(g)+H_{2}O(l)+4e^{-}\rightarrow 4OH^{-}(aq)

Overall equation: 2H_{2}(g)+O_{2}(g)\rightarrow 2H_{2}O(l)

Products of fuel cell reactions always lead to the production of water and electrical energy


  • It is a one step process in converting chemical energy directly to electrical energy.
  • No greenhouse gases are produced as a result of fuel cells.
  • Uses a variety of fuels.
  • Unlike batteries, do not need to be recharged.
  • Electricity can be generated on-site.


  • Requires constant fuel supply.
  • Expensive; manufactured in limited numbers as fuel cells are a relatively new technology.
  • Inverter is required to change direct current (DC) produced by the fuel cell to alternating current (AC) to use with electrical appliances used at home.
  • Transport is limited and hydrogen storage and distribution is dangerous.

See Also