Ion pair formation in concentrated aqueous solutions can alter the prediction of theories developed for dilute electrolyte solutions by modifying osmotic and activity coefficients, reducing electronic conductivity, and changing the structure of the double layer near charged electrodes. This phenomenology becomes more complex near aqueous interfaces, where ion-interface interactions and modified solvent statistics couple the pairing of ions and their approach to the interface. In particular, a recent series of studies suggests that the reverse fractionation of Na 2 CO 3 at the air-water interface, where carbonate ions become more surface active, may arise due to the association of ions into agglomerates near the interface. Understanding the specific effects of carbonate on interfacial solvation structure and its participation in ion pairing is of particular interest because carbonate is ubiquitous in CO 2saturated aqueous solutions suggesting that it likely plays a role in templating the interfacial solvation during CO 2 R. Compared to simple anions such as halides and anions with higher symmetry (sulfate, perchlorate), carbonate has a planar structure, which could have non-intuitive consequences on the alignment of interfacial water. Due to the divalent, polarizable nature of carbonate, its physical interactions at the electrode-electrolyte interface are not trivial to predict. All these factors motivate the present study, which seeks to provide a molecular understanding of the underlying physics, which govern ion interactions and solvation at electrode surfaces in the presence of carbonate.