Insights into the electrocatalytic reduction of CO₂ on metallic silver surfaces

The electrochemical reduction of CO2 could allow for a sustainable process by which renewable energy from wind and solar are used directly in the production of fuels and chemicals. In this work we investigated the potential dependent activity and selectivity of the electrochemical reduction of CO2 on metallic silver surfaces under ambient conditions. Our results deepen our understanding of the surface chemistry and provide insight into the factors important to designing better catalysts for the reaction. The high sensitivity of our experimental methods for identifying and quantifying products of reaction allowed for the observation of six reduction products including CO and hydrogen as major products and formate, methane, methanol, and ethanol as minor products. By quantifying the potential-dependent behavior of all products, we provide insights into kinetics and mechanisms at play, in particular involving the production of hydrocarbons and alcohols on catalysts with weak CO binding energy as well as the formation of a C-C bond required to produce ethanol.