Fuel cells use chemicals to create electricity. They are used, for example, to keep the lights on for astronauts in orbiting space stations. They hold promise in a variety of areas, such as fuel-cell cars. But the high price of catalysts used inside the cells has provided a roadblock to widespread use.

Now, nanoscale research at Stanford University has found a way to reduce the cost.

Multi-walled carbon nanotubes riddled with defects and impurities on the outside could eventually replace some of the expensive platinum catalysts used in fuel cells and metal-air batteries, according to Stanford scientists. Their findings are published in the May 27 online edition of the journal Nature Nanotechnology.

"Platinum is very expensive and thus impractical for large-scale commercialization," said Hongjie Dai, a professor of chemistry at Stanford and co-author of the study. "Developing a low-cost alternative has been a major research goal for several decades."