How Fuel Cells Work
A fuel cell is an electrochemical device that produces electricity by separating the fuel (generally hydrogen gas) via a catalyst. The protons flow through a membrane and combine with oxygen to form water - again with the help of a catalyst. The electrons flow from the anode to the cathode to create electricity. As long as the reactants - pure hydrogen and oxygen - are supplied to the fuel cell, it will produce electrical energy.
A single fuel cell is basically a piece of plastic between a couple of pieces of carbon plates that are sandwiched between two end plates acting as electrodes. These plates have channels that distribute the fuel and oxygen.
A factor that draws interest to the fuel cell is that it can operate at efficiencies two to three times that of the internal combustion engine, and it requires no moving parts. Since it converts the fuel, hydrogen, and oxygen directly to electrical energy, the only by-products are heat and water. Without combustion, fuel cells are virtually pollution free.
Although hydrogen is the most common fuel used to power a fuel cell, research is being done on a new type of fuel cell that operates using methanol (without using a reformer to convert it to hydrogen) and oxygen. However, this type of fuel cell remains in the early stages of development.