Measurements of the cell potential in two-electrode chronopotentiometry (CP) experiments at a cathodic current density of -10.0 mA cm -2 (Figure ) showed slightly higher cell potentials for both pairs of reactions. The aHER|BPM|OER cell operated at a cell potential of -1.65 V, which increased to -1.69 V by the end of the 13 hr experiment. The difference is likely due to solution and membrane resistances not accounted for in the load-line analysis and otherwise not characterized here. The aHER|BPM|GEOR cell began at roughly the predicted operating potential of -0.52 V, then monotonically increased in magnitude to -0.74 V after 20 hours. The increase in cell potential over time was observed previously and attributed to the slow formation of Pt hydroxides on the surface of the Au-Pt-Bi anode. Regardless, pairing the Pt HER cathode in 2 M H2SO4 with the GEOR anode reduced the cell potential by roughly the 1 V predicted by the LLA compared to water electrolysis. Seawater electrolysis is also a significant reaction for H2 evolution. Seawater is an important potential feedstock due to its widespread accessibility. A particular challenge is the generation of "free chlorine" species such as Cl2 or HClO which pose issues of safety and corrosion on the anode. While replacing OER or the chloride oxidation reaction with GEOR on a one-to-one molecular basis provides practical challenges of its own, we explored the technical possibility of improving operating cell potential for H2 evolution from seawater.