Proponents of replacing gasoline with hydrogen for fueling cars have to find a practical way to store hydrogen. One potential nanotech-based solution is presented by the recent demonstration that hydrogen can form chemical bonds with most of the carbon atoms in single-walled carbon nanotubes of the appropriate diameter (2.0 nm). From “The March of the Carbon Nanotubes“:

Stanford Synchrotron Radiation Laboratory (SSRL) researchers have surpassed by a surprising margin the Department of Energy’s goal for storing hydrogen within a unique material called carbon nanotubes…

Hydrogen—the most abundant element in the universe—is an attractive carrier of renewable energy. It can be used in fuel cells to produce electricity, with the only byproduct being water. However, developing safe and efficient methods of storing hydrogen remains a challenge.

[Graduate student Anton Nikitin] and his colleagues were able to pack seven percent by weight hydrogen into carbon nanotubes through the formation of bonds with carbon atoms. The chemically grown nanotubes are made of pure carbon and have walls a single atom thick. Because single-walled nanotubes are essentially all surface area, they can theoretically store an enormous proportion of hydrogen, making it a promising storage medium.

The research was published in the American Chemical Society’s Nano Letters (abstract).

Another way in which nanotechnology could provide hydrogen-fueled cars is by making the electrolysis of water to produce hydrogen more efficient. For the latest on this approach, see “Nanotechnology-based clean hydrogen for cars” on Roland Piquepaille’s blog.
—Jim