Hydrogen fuel cell
The hydrogen fuel cell is like a battery in that it generates electricity from an electrochemical reaction. A fuel cell uses an external supply of chemical energy and can run indefinitely, as long as it is supplied with a source of hydrogen and a source of oxygen (usually air). The source of hydrogen is generally referred to as the fuel and this gives the fuel cell its name, although there is no combustion involved. Oxidation of the hydrogen instead takes place electrochemically in a very efficient way. During oxidation, hydrogen atoms react with oxygen atoms to form water; in the process, electrons are released and flow through an external circuit as an electric current. Fuel cells can vary from tiny devices producing only a few watts of electricity, right up to large power plants producing megawatts.
All fuel cells are based around a central design using two electrodes separated by a solid or liquid electrolyte that carries electrically charged particles between them. A catalyst is often used to speed up the reactions at the electrodes. Fuel cell types are generally classified according to the nature of the electrolyte they use. Each type requires particular materials and fuels and is suitable for different applications.
They can be broadly classified as below
- Solid Oxide Fuel Cells (SOFC)
- Proton Exchange Membrane Fuel Cells (PEMFC)
- Alkaline Fuel Cells
- Direct Methanol Fuel Cells (DMFC)
- Phosphoric Acid Fuel Cells (PAFC)
- Molten Carbonate Fuel Cells (MCFC)
One of the most common methods for producing hydrogen is a process called electrolysis. This process combines electricity with various chemicals, called electrolytes, and a solid catalyst material. The ensuing reaction produces hydrogen, but the entire process uses a lot of energy and costly resources like platinum.
Now there is a quest to replace cheaper material than Platinum. Research is going on by various universities, scientists throughout world. We can only hope they succeed in research so as to enable this planet-saving technology within the reach of the common man.