It's said that breaking up is hard to do. That's undoubtedly true. And so is making up, as more than a few forlorn hearts have found. But when the lightning does strike, the electricity is lasting.
What's true for the affairs of the heart also holds for the affairs of hydrogen, as researchers at the Office of Science's Argonne National Laboratory have recently shown. Hydrogen is an important, energetic element, which is used in a variety of applications ranging from making semiconductors to powering fuel cells. However, it's also a hard, expensive one to make up in pure molecular form (Hydrogen usually shows up as a pair of hydrogen atoms – H2.)
As Nenad Markovic, a senior chemist at Argonne, noted, "People understand that once you have hydrogen, you can extract a lot of energy from it, but they don't realize just how hard it is to generate that hydrogen in the first place." Markovic led research at Argonne that recently showed a cheaper, cleaner way to make up pure hydrogen, one that begins with a breakup.
Specifically, the team took a look at breaking up water, taking the H2 out of the H2O. Water electrolyzers already do so, typically using special metals like platinum to speed, or catalyze, the reaction. However, in addition to being costly, platinum is also a better maker-upper than breaker-upper – it is better at fixing single hydrogen atoms up than separating them from water in the first place. (For more about catalysts, see "Seven things you might not know about catalysis.")
So Markovic and his team added clusters of a metallic complex, nickel-hydroxide, to the platinum catalyst. It ripped the water molecule apart and freed the hydrogen atoms to come together aided by the platinum catalyst. Altogether, it drove the reaction at about ten times its previous rate.
What's more, the researchers gave the scientists new insight into materials with virtually no defects, what are known as "single crystal systems." These materials, or at least their theoretical ideals, give scientists models to test their predictions against, and to make predictions on how materials might behave in the real world. In the case of Argonne, the modeled catalysis matched up with the real-world analysis, which may suggest ways to accelerate other reactions.
Breaking up is never easy, and making up is often hard. But as Argonne and the Office of Science have shown, when it happens, it can be electric, and the positive benefits are likely to be long-lasting.
For more information about Argonne National Lab, please go to: http://www.anl.gov/. And for more about DOE's Office of Science, please go to: http://science.energy.gov/.
Charles Rousseaux is a Senior Writer in the Office of Science.