While CCS can be employed along with a conventional Carbon-efficient EAF steelmaking process (especially from iron ore) or even Hydrogen or hydrocarbon can bee passed through central electrode, this question asks for an electrode for which no consumable (or at least, purposefully oxidizable) electrode would be used, and no Carbon-based reductant would be used (Hydrogen bases reductants usually has lower efficiency than carbon). Oxygen would be generated in anode and Metal at cathode, not unlike Aluminium.

Then, what would be the chemical composition of the electrode? If the electrode is submerged into the melt, Platinum-Rhodium alloys are best choice theoretically but too expensive economically. Can any other suitable Fast Ion conductor take the role, especially if the electrode is not kept in contact with metal but rather discharges electric spark, more like a conventional DC-EAF rather than an electrolysis cell?

In this case

• Too high voltage required for spark may reduce or even vaporize some metals and container walls. What ca n be done in this respect?
• How fast ion conductors would be joined with electronic conductor, especially taking into consideration drift of point defects that might generate porosity in the metal-oxide interface?