Using Nanotechnology to Produce Clean Energy From Water
QSI-Nano™ Science Chat, February 2006
As the world population climbs toward 6.5 billion, the demand for energy will only increase over time. Our non-renewable global oil reserve will eventually deplete, forcing us to look for viable alternatives. In addition, environmental impact awareness of burning such fuels has grown, further propelling our search for clean, efficient fuel.
The hydrogen fuel cell is widely viewed as a viable alternative to combustion engines. Hydrogen is a renewable fuel that produces zero emissions when used in a fuel cell. But where does the hydrogen come from? Nearly 50% of the hydrogen currently being produced is made by steam reformation, where natural gas is reacted on metallic catalyst at high temperature. While this process has the lowest cost, four pounds of the greenhouse gasses carbon monoxide (CO) and carbon dioxide (CO2) are produced for every one pound of hydrogen. Without further purification (which can also be costly) to remove CO and CO2, the hydrogen fuel cell cannot operate efficiently, so we are back to the original problem.
On the other hand, roughly 5% of hydrogen production is from water electrolysis. This reaction is the direct splitting of water molecules to produce hydrogen and oxygen. There are two reactions; the negative electrode produces hydrogen and the positive electrode produces oxygen.