Preliminary studies of a high-pressure electrochemical setup for e-CO₂RR over a modified copper electrode

Electrochemical CO₂ reduction reaction (e-CO₂RR) is a promising strategy for converting carbon dioxide into value-added chemicals using low-carbon electricity. Despite extensive investigation under ambient conditions, the influence of catalyst surface modifiers and elevated pressure remains insufficiently understood. This work investigates both electrode surface modification and reactor design aspects aimed at enhancing e-CO₂RR toward multicarbon (C₂+) products. In the first part, two molecular surface-functionalization strategies employing organic additives - physisorption and covalent grafting - were explored and evaluated independently, assessing their experimental feasibility and highlighting potential obstacles and possible solutions. In the second part, a custom-built high-pressure divided three-electrode electrochemical system was designed and preliminarily tested to enable future investigations of e-CO₂RR on organically modified copper electrodes under elevated pressure conditions. Through these experimental campaigns, a deeper understanding of the system behavior under various operating conditions was obtained. However, testing also revealed limitations in the maturity of the experimental setup, highlighting necessary improvements and guiding further development of the system for future mechanistic studies of the reaction.