I know that fuel cells can be made to run from other gasses than hydrogen. The first fuel cell was made to use methane. It seems to me that a such a fuel cell would be a good intermediate step between a petroleum to a hydrogen economy. Or perhaps natural gas? Basically anything to get us away from internal combustion.
Yes. I think they need rectifiers (?) to first split the hydrogen from the gasoline (or kerosene or diesel or heavy fuel oil or any other liquid except water containing hydrogen), then the hydrogen is fed into the fuel cell.