Electrochemical reduction of CO2 to formate catalyzed by electroplated tin coating on copper foam

•Sn/f-Cu electrode was prepared by electroplating Sn catalyst on Cu foam substrate.•Sn/f-Cu electrode is used as cathode for electrocatalytic reduction of CO2.•Average current density can reach to ∼8 mA cm−2 during CO2 electrolysis.•Sn/f-Cu electrode shows excellent performance for reduction of CO2 to formate.

Sn/f-Cu electrode has been prepared by electrodeposition Sn on a Cu foam substrate in aqueous plating solution, which has been used as the cathode for electrochemical reduction of carbon dioxide (CO2) in aqueous KHCO3 solution. Here, we have explored the effects of the deposition time and the electrolysis potential on the Faradaic efficiency for producing formate. The results demonstrate that maximum Faradaic efficiency of 83.5% is obtained at −1.8 V vs. Ag/AgCl when the Sn/f-Cu electrode is prepared by electrodeposition for 35 min. The Sn/f-Cu electrode exhibits excellent catalytic activity for CO2 reduction compared with the Cu foam electrode and the Sn plate electrode. The average current density and the production rate of formate for the Sn/f-Cu electrode are more than twice those for the Sn plate electrode during electrochemical reduction of CO2.

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