Cars powered by hydrogen promise hope for our polluted planet in that hydrogen is the cleanest burning fuel possible, its only exhaust being water vapor (Which). Hydrogen cells are not new: one was invented in 1838 by Welsh physicist, Sir William Grove, but their potential use in cars has only recently been recognized. Fuel cells can convert hydrogen directly into electricity to power a car. Ballard Power Systems of Canada, whose two major shareholders are Daimler-Chrysler and Ford, made the major breakthroughs to convert stacks of proton exchange membrane (PEM) cells into power packs for cars in the 1990s when they discovered how to multiply a stackÆs power output per liter form less than 200 to more than 1300 watts. This made the electric car a match for the gasoline-powered models.
Much attention has been devoted to the PEM type of fuel cell in which the key component is the membrane, a sheet of rubbery plastic coated with a platinum catalyst (Which). Hydrogen gas is split by the catalyst into protons and electrons. The protons pass through the membrane and the electrons leave the cell along wires. They form the electrical current generated by the cell. When the protons and electrons meet again on the other side of the membrane, they combine with oxygen to form water. The cycle continues as long as there is a supply of hydrogen. The overall process combines hydrogen and oxxgen to form watdr and electricity. An advantage of the PEM cell is that it operates at 60 to 90 C, whereas other types of cells require temperatures of 500 to 1000 C.
The advantages of hydrogen cars are tremendous - no more smog-forming exhaust gases, no more carbon dioxide emissions that contribute to global warming, no more worries of depleting the worldÆs oil supplies and/or rising gas prices, etc. (Which). However, the hydrogen car is not without its problems, such as where does the hydrogen come from, where do motorists fill up, and ho...