An inexpensive catalyst generates hydrogen. (Chemistry).

When it comes to cleanliness, fossil fuels can't compete with hydrogen gas, which produces only water when it burns. But getting the hydrogen in the first place isn't so clean. Unless energy researchers overcome several stumbling blocks--such as the typical use of fossil fuels to generate the gas--the world's autos won't be filling up on truly clean hydrogen anytime soon.

A new catalyst that accelerates reactions that create hydrogen from renewable feedstocks could be part of the solution. At the University of Wisconsin-Madison, James Dumesic and his colleagues recently developed a chemical process that uses metal catalysts to generate hydrogen from sugar and other carbohydrates (SN: 10/12/02, p. 235). Unfortunately, they used catalysts made from platinum, an expensive precious metal to promote this reaction.

Dumesic and his coworkers have now tested more than 300 additional metal catalysts. In the June 27 Science, the researchers report that they've identified a much less expensive nickel-tin combination that, in their process, can generate hydrogen at least as well as the platinum catalyst does. Plain nickel catalysts generate polluting methane along with hydrogen, but the addition of tin staves off methane formation, says Dumesic.

While continuing to search for even better catalytic combinations, Dumesic and his colleagues are now studying how the nickel-tin catalyst behaves at the atomic scale. Meanwhile, researchers at Virent Energy Systems--a small Madison company cofounded by Dumesic--are investigating the long-term, stability of the new nickel-tin catalyst and determining whether it will work with easily available sugar sources, such as agricultural wastes.--J.G.