Is there a polar liquid with a high electrolysis potential?

I'm trying to use $\ce{Na2SO4}$ for intercalation of sulfate ions in van der Waals stacked materials (as anodes). With water as the solvent, there is some indication of hydroxyl radical forming due to the applied potential being larger than the standard potential of water electrolysis (1.23 V).


I am aware that hydroxyl scavengers such as ascorbic acid can be used to, well, scavenge hydroxyls. Yet I'm wondering if there is a solvent for $\ce{Na2SO4}$ that would only decompose at a higher potential difference.


