Hydrogen alone makes no sense. Now, if you just add some carbon to that hydrogen and make a liquid hydrocarbon fuel, you’d really have something.
Get the carbon from biomass and you’d be “carbon neutral,” too. No releasing that evil carbon stored in coal.
It is possible to store hydrogen by high energy ball milling boron nitride in a hydrogen atmosphere.
Although it seems like engine modification would be necessary to prevent hydrogen embrittlement.