Sodium Borohydride
Millenium Cell's "hydrogen-on-demand" system is what Chrysler has been using for ages in their experimental fuel-cell vehicles under the name of the "Natrium" system.
Pass a solution of (basically) hydrated borax over a catalyst to produce free hydrogen and borax solution. the former goes to the fuel cell to mix with atmospheric oxygen to form water and electricity, the latter is stored for rehydrogenating at a later date.
Great idea - one of the more promising ideas for storing hydrogen for fuel-cell vehicles. Chrysler is claiming a 30mpg (presumably US mpg rather than real money) performance from its "Natrium" van.


