Yeah, you might as well run your engine on hydrochloric acid.

There is just no way to store hydrogen in a small container, with any efficiency. Lithium borohydride is a pretty compact source, but at the end of the journey you have lithium borate, and a whole lot of chemistry and energy is required to recreate the hydride. Some rare and exotic metals, like palladium, can store hydrogen -- which defeats the purpose of lightweight energy. Liquefy it, like fuel for the space shuttle ... it is ridiculously cold, and explosively boils if you look at it wrong. Or compress it, for a very short ride before another fill-up is needed. Or you can tow a zeppelin on a long umbilical leash.