In tests reported in this week's issue of the journal Science, the group showed that this modified catalyst was effective and stable for performing the reaction repeatedly.

"This work represents a significant advance in the application of molecular electrocatalysts for hydrogen production and oxidation," says DuBois. It shows, he says, that these highly reactive molecular catalysts can operate efficiently under conditions that may be practical for electrolyzers and fuels cells. "This is an important step toward moving bio-inspired catalysts from conception to practice."

Nate Lewis, a professor of chemistry at Caltech, agrees. "This is an important step toward the development of a full system that splits water from sunlight," he says. But Lewis notes that finding a way to attach the catalysts to a surface so that they can be used in an electrode is just one piece of the puzzle.

John Turner, a research fellow in energy sciences at the National Renewable Energy Laboratory in Golden, CO adds that, "the major barrier for hydrogen production from water and fuel cells for transportation is not hydrogen catalysis, but oxygen catalysis."

Nickel-based catalysts are already used in large multi-megawatt commercial electrolyzers, but these catalysts are much less efficient than platinum ones and tend to be very large--typically around 10 square meters.

Turner notes that the current produced by Artero's catalyst is still orders of magnitude less than can be achieved with platinum. Artero says this can be fairly easily remedied. He notes that the nanotubes used in his team's experiments received only a low loading of the catalytic material. Increasing this should boost the current: "It's a gap that we can fill," he says.