Potentio electrochemical impedance spectroscopy (PEIS) was performed before all the experiments to measure the electrolyte resistance between the Luggin capillary of the reference electrode and the surface of the cathode. PEIS was performed by setting a single sine wave mode scanned from frequencies 100 kHz to 30 Hz by measuring 10 points per decade, at an amplitude of 20 mA with 3 measures per frequency, and the scan was repeated once. The working electrode voltage was set to 0 V vs open circuit, the voltage range was set to -10 V to 10 V and the current range was set to Auto. 85 % of uncompensated IR drop was compensated through positive feedback using the Biologic EC-Lab software. 15 % of uncompensated IR drop was compensated manually during the calculations. LSV was performed at a scan rate of 5 mV/s from 0 to -3 V vs. RHE, with an acquisition time of 0.05 s. The voltage range was set to -10 V to 10 V and the current range was set to Auto. CA was performed with an acquisition time of 0.1 s, with a voltage range of -10 V to 10 V and the current range was set to 1 A. For the stability studies, similar settings were used as that of CA but with an acquisition time of 1 s.