If water in cation's first hydration shell serves as the proton source in the CO2RR as suggested by the trend of 𝐸 * * , the strength of the interaction between cations and water, i.e., ∆𝐺 /0& , is expected to impact the energetic cost of changing the configuration of these water molecules when participating in the RDS. Indeed, 𝜆 !" ! 44 and ∆𝐺 /0& are linearly correlated (Fig. ).