Morphological Stability of Sn Electrode for Electrochemical Conversion of CO2

The morphological stability of 100 nm Sn particles as the electrode for electrochemical reduction of CO2 was studied in a full electrochemical cell at room temperature and pressure. A degradation of selectivity towards CO2 reduction, accompanied by the pulverization of Sn particles was observed during long-term measurements. During the pulverization process, the size of Sn particles decreased from similar to 100 nm to similar to 3 nm in approximately 60-hour operation. The Faradaic efficiency towards the formation of formate decreased from similar to 90% to similar to 56%. On the contrary, the Faradaic efficiency for H-2 evolution increased during the measurement. The degradation of the selectivity towards CO2 reduction is primarily attributed to the decrease of the potential at the cathode.