A durability test was performed to determine the effects of degradation of the Au-Pt-Bi electrocatalyst and BPM on the cell potential over an extended period. The two-electrode chronopotentiometry at -10.0 mA cm -2 in an aHER|BPM|GEOR cell showed that the cell potentials began at -0.55 V, and remained under -0.7 V for more than 80 h (Figure ). The cell potential increased by 267 mV over the 160 h experiment. Prior experiments suggest that bismuth dissolution from the Au-Pt-Bi electrode impacts the GEOR by steadily causing the formation of Pt oxide/hydroxide. Periodic bismuth redeposition (via a quick cathodic pulse on the anode in the presence of Bi 3+ in the solution) has been shown to be an effective measure to enhance the lifetime of Au-Pt-Bi anode. NMR measurements of the cathodic chamber electrolyte showed the presence of glycerol in the solution after 6 hours of electrolysis. Over a 24-hour period of electrolysis the concentration of glycerol in 25 mL of catholyte increased to 18 mM. After the CP experiment, the electrolytes were left in the cell for 48 hours to determine if the electrolysis was driving glycerol crossover.