writes A phys.org article says UK researchers have made a breakthrough that could make ammonia a practical source of hydrogen for fueling cars. From the article: "Many catalysts can effectively crack ammonia to release the hydrogen, but the best ones are very expensive precious metals. This new method is different and involves two simultaneous chemical processes rather than using a catalyst, and can achieve the same result at a fraction of the cost. ... Professor Bill David, who led the STFC research team at the ISIS Neutron Source, said 'Our approach is as effective as the best current catalysts but the active material, sodium amide, costs pennies to produce. We can produce hydrogen from ammonia "on demand" effectively and affordably.'"
The full paper
. The researchers claim that a two-liter reaction chamber could produce enough hydrogen to power a typical sedan.