Tailoring Electrocarboxylation Pathways on Lead Cathodes: Insights into Electrolysis Mode

Abstract

Electrocarboxylation, the electrochemical addition of CO₂ to organic substrates using renewable energy, offers a promising approach for carbon capture and utilization. However, commercial viability remains limited due to poor product selectivity and yields. In this work, we investigate how the electrolysis mode – chronoamperometry (CA) versus chronopotentiometry (CP) – influences the electrocarboxylation mechanisms of phenyl-activated substrates, Benzaldehyde, Styrene, and Benzylbromide, on Lead electrodes. By employing cyclic voltammetry (CV), in situ FTIR, and bulk electrolysis, we explore how these modes affect product selectivity and reaction efficiency. Our results show that substrate-activated mechanisms, such as those observed for Benzaldehyde and Benzylbromide, achieve higher selectivity and reduced side-product formation under CA conditions, while CP leads to increased side reactions. In contrast, Styrene exhibits more complex behavior, with CP favoring di-carboxylation, while CA enhances mono-carboxylation. These findings highlight the significant impact of electrolysis mode on controlling electrocarboxylation pathways, providing valuable insights for optimizing selective and efficient synthesis processes.