Lateral Adsorbate Interactions Inhibit HCOO- While Promoting CO Selectivity for CO2 Electrocatalysis on Ag

The analysis presented in this manuscript helps bridge an important fundamental discrepancy between the existing theoretical and experimental knowledge regarding the performance of Ag catalysts for CO 2 electrochemical reduction (CO 2 ER). The results demonstrate how the intermediate species *OCHO is formed readily en-route the HCOO – pathway and plays a decisive role in determining selectivity of a predominantly CO producing catalyst such as Ag. Our theoretical and experimental approach develops a better understanding of the nature of competition as well as the complex interactions between the reaction intermediates leading to CO, HCOO – and H 2 during CO 2 ER. Details of computational and experimental methods are present in the Supporting Information provided.