Figure shows the j-E characteristics of hydrogen evolution from a Pt-Ni foam cathode as measured in simulated seawater (sHER). A load-line analysis predicted operating cell potentials of Vop = -0.35 V + VBPM = -1.18 V for a sHER|BPM|GEOR cell and Vop = -1.41 V + VBPM = -2.24 V for a sHER|BPM|OER cell at an operating geometric current density of -10.0 mA cm -2 .