The electrochemical reduction of CO 2 is a very promising approach providing a means to manage intermittent renewable electricity production by converting it to a chemically valuable form, while recycling climate change-inducing CO 2 . 1 Understanding the pathways for the (electro)chemical transformations involved in CO 2 ER is critical to advance its technological utilization. The 2 proton-electron transfer products of CO 2 ER, namely CO and HCOO -are highly attractive due to relatively low overpotentials needed to drive their production, and high achievable Faradaic efficiencies. The need to balance the performance with low cost electrodes has led to an increased interest in using Ag as a CO 2 reduction catalyst, which has a high selectivity to CO while being 100 times cheaper than the alternative Au. It is widely accepted that the formation of CO from CO 2 on transition metal catalysts with an aqueous electrolyte proceeds via the * COOH species, whereas the formation of HCOO -proceeds via the bidentate O-bound * OCHO species, both forming after a single CPET step. Consideration of the relative limiting potentials (UL) alone dictates that the formation of H 2 is most thermodynamically feasible on Ag(110), followed by HCOO -and then CO (see Figure ; Figure depicts the limiting potentials with varying surface facets of Ag). Interestingly, this conclusion does not reconcile with the experimental observations of the formation of CO as the major product of CO 2 ER on Ag, H 2 as a by-product (through the hydrogen evolution reaction, HER), with the detection of only trace amounts of HCOO -for intermediate applied potentials of ca. -0.9 V to -1.3 V. For applied potentials more or less negative of this range, the Faradaic efficiency for H 2 dominates that for CO. However, irrespective of the applied potential, the experimentally observed Faradaic efficiency for the formation of HCOO -remains significantly lower (<10%) relative to CO and H 2 . The reasons for this discrepancy and the role of the stable species * OCHO in the catalytic performance of Ag is not well understood.