First came the promise of pollution-free energy. Then came the daunting list of economic and technical challenges. It seemed as if plans for the hydrogen economy might never make it off the drawing board. But with a number of research programmes showing promising results, hydrogen’s star may be rising.
Hydrogen’s promise as a clean fuel relies on the fact that bringing hydrogen and oxygen together releases nothing but energy and water. Hydrogen is the third most abundant element in the Earth’s atmosphere but it is almost entirely bound up in other compounds. Extracting it requires energy up front.
