Fig. 5. (A) Chronovoltammetric curves and (B) product formation rates during CO electrolysis using a Cu NPs + 5 wt% CST sample, at j = 500 mA cm⁻² current density, applying different electrolyte solutions. (C) Product distribution during a long-term CO electrolysis at j = 200 mA cm⁻², using a Cu NPs + 5 wt% CST sample and a 5 M KOH electrolyte solution. The electrolyte flow rate was 1 cm³ min⁻¹ while the CO feed rate was maintained at 26.5 sccm in all experiments.