The capacitive behavior of GR-AC electrodes exposed to CO2 at different voltage windows was further evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The CV curves are rectangular-shaped up to -1.4 V and exhibit typical double-layer charge storage behavior (Figure ). At -1.6 V, the CV curve deviates from the ideal double layer behavior due to an increase in current after the charging curve exceeds -1.4