Fig. 7: Theoretical calculations.

The free energy for the formation of *COOH (G(*COOH)), *H (G(*H)), and their energy difference (G(*COOH)-G(*H)) on Ag (111) plane at various (a) K⁺ concentrations (1/18 per H₂O molecule) and (b) *H coverages (1/9 per site). The light blue, purple, red, gray and white balls represent Ag, K, O, C and H, respectively.