Fig. 2. (A) Contact angles of 1 M KOH droplets at Cu NPs-GDE with varying Capstone content (5–30 wt%). (B) Cell voltage recorded for Cu NPs + 5 wt% CST sample during electrolysis performed at 100–500 mA cm⁻² current densities in 1 M KOH electrolyte solution at room temperature. The electrolyte flow rate was 0.5 cm³ min⁻¹, while the CO flow rate was 26.5 sccm. All chronovoltammetric measurements were performed on the same electrode. (C) Product distribution at different current densities with 5 wt% CST containing GDEs. Error bars were calculated from at least two individual measurements. (D) Product distribution was obtained at 300 mA cm⁻² current density using Cu NPs-coated GDE with varying CST content. The amount of the formed products were either determined only from the gas outlet stream (left column in each case) or by connecting the gas and liquid outlet stream after a water separator (right column in each case). For further information, see Fig. S10 (ESI†).