Ex situ electrochemical measurements were conducted in a three-electrode setup in a PECC- ). The conditioning was done for 4 h, which means 650 CV from 0.5-1.6 V vs. RHE with 100 mV/s scan rate. The full protocol is described in Figure . The conditioned samples were then used to study the impact of the alkali metal cations. For this purpose, they were activated in the respective 1 M MOH solution (M = Li, Na, K, Cs). The activation was always performed one day after the conditioning.