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Electrochemical CO₂ reduction is a promising carbon capture and utilisation technology. Herein, a continuous flow gas diffusion electrode (GDE)-cell configuration has been studied to convert CO₂ via electrochemical reduction under atmospheric conditions. To this purpose, Cu-based electrocatalysts immobilised on a porous and conductive GDE have been tested. Many system variables have been evaluated to find the most promising conditions able to lead to increased production of CO₂ reduction liquid products, specifically: applied potentials, catalyst loading, Nafion content, KHCO₃ electrolyte concentration, and the presence of metal oxides, like ZnO or/and Al₂O₃. In particular, the CO productivity increased at the lowest Nafion content of 15%, leading to syngas with an H₂/CO ratio of ~1. Meanwhile, at the highest Nafion content (45%), C₂₊ products formation has been increased, and the CO selectivity has been decreased by 80%. The reported results revealed that the liquid crossover through the GDE highly impacts CO₂ diffusion to the catalyst active sites, thus reducing the CO₂ conversion efficiency. Through mathematical modelling, it has been confirmed that the increase of the local pH, coupled to the electrode-wetting, promotes the formation of bicarbonate species that deactivate the catalysts surface, hindering the mechanisms for the C₂₊ liquid products generation. These results want to shine the spotlight on kinetics and transport limitations, shifting the focus from catalytic activity of materials to other involved factors.