Vehicle fuel-cell technology releases hydrogen on demand

Prof Travis Williams and colleagues from the University of Southern California (USC) devised a way to efficiently catalyse the release of hydrogen from ammonia borane.

Hydrogen fuel cells are now a relatively mature technology; however, as a gas, hydrogen can generally only be stored in high-pressure or cryogenic tanks. As Williams noted, in the case of a vehicle with a tank full of hydrogen, this could be a problem in the event of a collision.

Because of this, several groups have taken an interest in trying to use ammonia borane — a nitrogen-boron complex that can be stored as a stable solid — as a fuel.

However, until now it has proved difficult to efficiently produce enough hydrogen from boron compounds to make them viable for use in conjunction with fuel cells.

The team has developed a catalyst system that releases enough hydrogen from its storage in ammonia borane to make it usable as a fuel source. Moreover, the system is air stable and reusable, unlike other systems for hydrogen storage on boron and metal hydrides.