There are people who are trying to sequester hydrogen without the high compression and heavy steel tanks. That would be the magic bullet for aircraft hybrids like the subject of our discussion. H2 > Fuel Cell > Ducted Electric Fans would be brilliant.
Why the extra complication and weight of a fuel cell/electric motor? Just burn the H2 in a gas turbine.
While the electric propulsion is interesting, I just don't see it being practical unless there is a massive breakthrough in battery technology resulting in much lighter batteries.