Role of the oxide layer on Sn electrode in electrochemical reduction of CO2 to formate

- The oxide layer on Sn electrode is essential for reduction of CO2 to formate.
- Seriously hydrogen evolution reaction occurred on the E-Sn electrode.
- The faradaic efficiency obtained on the E-Sn electrode was 43%.
- The faradaic efficiency obtained on the OE-Sn electrode was 85%.