Real-Time Product Detection during CO2 Electroreduction on SCILL-Modified Cu Catalysts

Modifying the chemical environment of active surfaces with ionic liquids (IL) is an emerging strategy for tailoring novel electrocatalytic systems, including carbon dioxide reduction (CO₂RR). Although copper (Cu) catalysts have recently gained more attention in this field, their modification with ILs is yet to be investigated. This work tested a range of common hydrophobic ILs impregnated into carbon-supported Cu catalysts, following the “solid catalyst with ionic liquid layer” (SCILL) approach. The latter was used to showcase the applicability of real-time product detection for CO₂RR employing electrochemical mass spectrometry. The observed patterns of C₁ to C₃ product selectivity offered valuable insights into the intricate reaction mechanism. In addition, increasing the size of the IL cation showed an opposite and significant effect on the reaction selectivity. The obtained qualitative results were partially compared with conventional long-term experiments.