All electrochemical experiments were carried out using a Vionic potentiostat (from Metrohm). A commercial three-compartment micro flow cell (ElectroCell, A/S) was used for the CO2RR experiments. A Fumasep bipolar membrane (from FuMA-Tech), in forward mode, was used to separate the cathodic and anodic compartments. A GDE with a geometrical area of 2 cm 2 was utilized to separate the cathodic side into two sections: one for the gaseous CO2 reactant and one for the aqueous catholyte. A leak-free reference electrode (LF-1 reference electrode (Ag/AgCl) 1mm) was used in the catholyte compartment. The GDE was embedded in a Ti-frame electrode. An Ir-MMO (Iridium-mixed metal oxide) on Ti electrode from Electrocell was used as counter electrode. The Ag-coated GDE was used as a working electrode. The CO2 reactant was continuously fed to the cathode compartment at a volumetric flow rate of 25 ml/min using a Thermal Mass Flow Controller (Bronkhorst, Serie EL-FLOW Prestige). The anolyte and catholyte solutions (0.5 M KHCO3) were circulated at a rate of 8 ml/min using peristaltic pumps (Welco, OEM-peristaltic pump WP1000). KHCO3 has been reported to lead to lower current densities compared to KOH or acidic solution, however it is less harmful and facilitates potential scale-up of the CO2RR systems. The measured electrode potentials were re-scaled to the reversible hydrogen electrode (RHE) reference by applying the Nernst equation using the pH of 7.2.