To make our study fully comprehensible to both experimentalists and theoreticians alike, we like to briefly address the topic of semantics concerning the adsorbates used within this work. All calculations were performed in charge-neutral systems as the electrodes act as electron reservoirs ensuring charge neutrality, as should be true for any electrochemical interface in equilibrium . Therefore we describe the carbonate adsorbate as CO 3 since no additional charges are introduced into the system. This does, however, not imply that the carbonate moiety is charge neutral after adsorption on the respective surface. All calculated adsorption energies are listed in the table .