We suggest that the primary factor determining these features is the steric constraint on ion solvation imposed by the confining wall, which leads to states of relative over-or undercoordination that respectively stabilize or destabilize the various ion pairing states. Through comparison to an implicit carbon model, we determine that graphene's lattice structure does not significantly affect ion pairing behavior. Explicit incorporation of graphene in the model is, however, crucial for capturing the extent of contact ion pairing in the system: through analysis of partial charges on the carbon atoms, we show that graphene polarizes in response to adsorbed ions, which is consistent with a decrease in the electric field within the channels and destabilization of the contact ion pair. Our work thus demonstrates the important roles of solvation effects and the confining wall's electronic structure in dictating the structure of nanoconfined electrolyte solutions. Such insights may be useful for developing pore materials and geometries which minimize ion pairing and are thus expected to improve both ionic conductivity and selectivity -key performance metrics for energy storage and separations technologies.