[e_y_]

I'm assuming you're asking about ejecting the electrons and remaining positively-charge hydrogen ions separately, since keeping the hydrogen around would be a waste of mass.

I'm no expert at space propulsion, but I think this would have a few issues:

- Hydrogen has a pretty high ionization energy, even higher than Xenon

- As you said, static charge buildup

- Momentum = mass * velocity. Electrons have 1/1836 the mass of a proton, so for the same momentum you need a much higher velocity

- Imparting velocity is harder for low-mass particles because they tend to zoom off very quickly if not contained