We also observe a correlation in the appearance of a δC-H vibration band at 1298 cm -1 19 with the bidentate signal merging into a broader band at more cathodic potentials of -1.12 V vs RHE as can be seen in Figure . The same correlation is observed using a lithium borate buffer solution with a bulk pH of 6.9 albeit at higher overpotentials (Figure ). These experiments suggest that pH plays an important role in CO 2 ER at lower overpotentials due to its implications on the formation of * H on the Ag electrode. Adsorbate-adsorbate interactions are known to play an important role in determining the energetics of surface reactions including CO 2 ER. Considering the high likelihood of the presence of * OCHO species on the Ag catalyst surface, we investigate its influence on the adsorption energies of reaction intermediates involved in the 2-electron reduction processes during CO 2 ER. The free energy diagram in Figure shows that the presence of * OCHO weakens the * H binding significantly (green pathway in Figure and Figure ) whereas the effect of its presence on the binding energies of the * COOH, *OCHO and * CO species is relatively smaller. As a result, the UL for the formation of H 2 and HCOO - (both proceeding via the Volmer step), become much less favorable and comparable to the UL for the formation of CO.