Designing Microenviroments for Selective CO₂ (Photo)Electroreduction

(Photo)electrochemical reduction of carbon dioxide is a process in which multiple proton-electron transfers are necessary to yield valuable carbon-based products. This process also offers an efficient strategy to reduce the presence of greenhouse gases in the atmosphere while concurrently producing valuable carbon-based products. However, most of the existing CO₂ reduction catalysts still exhibit reduced selectivity for CO₂ reduction products and high activity for the competing hydrogen evolution reaction.<br/>To understand how to tune catalytic activity and selectivity, the identification of specific structure–reactivity relationships can inform catalyst development. We demonstrate that the confined reaction environment enables changes in reaction selectivity and can impart atypical catalytic behaviors. In this talk, we clarify the role of subsurface oxygen, water, and CO₂ on Cu and Ag based systems for CO₂ electroreduction. We show the development of a predictive framework to tune the selectivity of CO₂ reduction on Cu and Ag by examining a series of polymeric and molecular modifiers. We also demonstrate how considerations about the local reaction environment have relevance for photoelectrochemical systems. This understanding can reveal design principles that enable development of active and selective catalysts and provide further insights into the CO₂ reaction mechanism on existing catalyst such as copper and silver.