Alkaline Water Electrolysis with RbOH
Of course! Rb is more electropositive than hydrogen, so hydrogen is released.

As you mention, $\ce{RbOH}$ is a bit more expensive than $\ce{NaOH}$. At present, $\ce{RbOH}$ is ~US\$500/kg and $\ce{NaOH}$ is ~US\$500/tonne, three orders of magnitude cheaper.

You might use $\ce{CsOH}$ or $\ce{FrOH}$, too. The Fr will even illuminate the reaction with Cherenkov radiation.