Developers Tout Iron-Based Fuel-Cell Catalyst

U.S. government researchers are developing an iron-based material that promises the efficiency of platinum catalysts at one-thousandth the cost.

They says the key is an iron-based molecular hydrogenase complex that can break down hydrogen molecules and help them combine with oxygen in a process that creates electricity and forms water.

Iron-based hydrogenase catalysts can produce 9,000 molecules of H₂ per second. For fuel cells, the challenge is to efficiently reverse that process. Splitting a molecule of hydrogen releases two electrons that can be captured as current.

Researchers at the Dept. of Energy's Center for Molecular Electrocatalysis say their custom-designed, iron-based hydrogenases can split two H₂ molecules per second. That rate is thousands of times more efficient than any other competing iron-based catalyst and competitive with most commercially available platinum catalysts, according to the developers.

The DOE team, led by Morris Bullock, reports in today's Nature Chemistry that its catalyst has an overpotential (a measure of voltage efficiency) of 160-220 millivolts.