For the electrochemical characterization, CVs were recorded before and after aCGDE. The initial potential for all measurements (unless otherwise mentioned) was set around the open circuit potential (ca. 1.00 V RHE ), the lower potential limit to 0.00 V RHE and the upper potential limit to 1.05 V RHE . For some measurements the upper potential limit was increased to 1.25 V RHE . When the upper potential limit was increased to 1.25 V RHE , the initial potential was set to 1.20 V RHE . The scan rate for all measurements was 50 mV s -1 and the initial scan rate was always negative (negative potential scan). During the aCGDE in step B1 and in step B2 the potential of the AE was held at the initial potential (1.00 V RHE ).