Promise for fuel cells

New quantum calculations and computer models show that carbon nanotubes "decorated" with titanium or other transition metals can latch on to hydrogen molecules in numbers more than adequate for efficient hydrogen storage, a capability key to long-term efforts to develop fuel cells.

US National Institute of Standards and Technology theorist Taner Yildirim and physicist Salim Ciraci of Turkey's Bilkent University report their "unanticipated" findings in the online issue of Physical Review Letters.

Using established quantum physics theory, they predict that hydrogen can amass in amounts equivalent to eight percent of the weight of "titanium-decorated" singled walled carbon nanotubes. That's one-third better than the six percent minimum storage-capacity requirement set by the FreedomCar Research Partnership involving the Department of Energy and the USA’s "Big Three" automakers.

This computer model shows how titanium atoms (dark blue) can attach above the centres of single-walled carbon nanotubes (light blue). Quantum calculations and modelling by a NIST researcher and his colleague reveal that each titanium atom can bond with four hydrogen molecules (red), a finding that could lead to efficient fuel cells for future automobiles.