Cool Chemistry for Fuel Cells

This cool hydrogen research could nevertheless lead to a hydrogen fuel that powers not only cars, but laptop computers, cellphones, digital cameras, and other electronic devices as well.

“We have a class of materials in which we can change the components nearly at will,” said UCLA’s Omar Yaghi, “There is no other class of materials where one can do that. The exciting discovery we are reporting is that, using a new material, we have identified a clear path for how to get above seven percent of the material’s weight in hydrogen.”

The materials, which Yaghi invented in the early 1990s, are called metal-organic frameworks (MOFs), which are like scaffolds made of linked rods — a structure that maximizes the surface area. MOFs are crystalline “sponges” and their nanoscopic pores can absorb and store gases. One gram of a MOF has an internal surface area equivalent to a football field.

Yaghi’s laboratory has made more than 500 MOFs, with a variety of properties and structures. “We have achieved 7.5 percent hydrogen; we want to achieve this percent at ambient temperatures,” said Yaghi, a member of the California NanoSystems Institute. “We can store significantly more hydrogen with the MOF material than without the MOF.”

In the push to develop hydrogen fuel cells to power cars, cellphones and other devices, one of the biggest challenges has been finding ways to store large amounts of hydrogen at the right temperatures and pressures. Yaghi and his colleagues have now demonstrated the ability to store large amounts of hydrogen at the right pressure; in addition, Yaghi has ideas about how to modify the rod-like components to store hydrogen at ambient temperatures (0-45°C).

Adapted from a UCLA press releases