(Invited) Electrochemical CO2 Reduction to Formic Acid on Crystalline SnO2 Nanosphere Catalyst

The electrochemical reduction of CO₂ is a reaction of much current interest as a possible reaction for energy storage.¹ To date, formic acid, carbon monoxide, methanol, and oxalic acid have been prepared by this way. However, the key technological challenge for electrochemical reduction of CO₂ is the preparation of the electrode with high catalytic activity, high selectivity and long term stability. Considering these difficulties, developing new material synthesis technology to give innovative new catalysts with optimal performance is the priority.

 Tin (Sn) and copper (Cu) are considered as promising electrocatalysts to convert carbon dioxide (CO₂) to fuels (e.g. formate, methanol or hydrocarbons) because of their low cost, easy availability and reasonable overall Faradaic efficiency towards fuel production.² However, the deactivation of Sn metal electrodes during CO₂ reduction is very fast, and requires at least 0.86 V of overpotential to attain a CO₂ reduction partial current density of 4−5 mA cm^-2 in an aqueous solution saturated with 1 atm CO₂.³ Combined with the advantages of metal tin, we here report a simple one step synthesis of crystalline SnO₂ nanosphere with good electrochemical performance of high catalytic activity and high selectivity.