Influence of Support Material on the Structural Evolution of Copper during Electrochemical CO₂ Reduction

The copper-catalyzed electrochemical CO₂ reduction reaction represents an elegant pathway to reduce CO₂ emissions while producing a wide range of valuable hydrocarbons. The selectivity for these products depends strongly on the structure and morphology of the copper catalyst. However, continued deactivation during catalysis alters the obtained product spectrum. In this work, we report on the stabilizing effect of three different carbon supports with unique pore structures. The influence of pore structure on stability and selectivity was examined by high-angle annular dark field scanning transmission electron microscopy and gas chromatography measurements in a micro-flow cell. Supporting particles into confined space was found to increase the barrier for particle agglomeration during 20 h of chronopotentiometry measurements at 100 mA cm⁻² resembling long-term CO₂ reduction conditions. We propose a catalyst design preventing coalescence and agglomeration in harsh electrochemical reaction conditions, exemplarily demonstrated for the electrocatalytic CO₂ reduction. With this work, we provide important insights into the design of stable CO₂ electrocatalysts that can potentially be applied to a wide range of applications.