Solar cell driven electrochemical process for the reduction of CO2 to HCOOH on Zn and Sn electrocatalysts

• Reduction of CO2 to products was studied using solar energy on Zn and Sn.
• Co3O4 electrode was used as cheap anode in place o conventionally used Pt.
• HCOOH acid was the only product formed for both the electrocatalysts.
• Maximum HCOOH formed in 0.2 M KHCO3 for 10 min reaction was 430 μmol.

This article presents the reduction of carbon dioxide (CO2) to products using solar energy on Zn and Sn electrocatalysts. Cobalt oxide (Co3O4) electrode was used as an anode for water dissociation reaction. Zinc (Zn) and tin (Sn) electrocatalysts were used as cathodes for photo electrochemical reduction of CO2. The extent of CO2 reduction was investigated in presence of various concentrations of bicarbonates of sodium and potassium electrolytes. The samples were collected for the reaction time of (10, 20, 30, 40, 50 and 60 min) and analyzed by using ultra fast liquid chromatography (UFLC). Formic acid (HCOOH) was the only product formed for both the electrocatalysts and respective results and optimized conditions were given in detail. Maximum HCOOH formed in 0.2 M KHCO3 for 10 min reaction was 430 μmol and 400 μmol using Sn and Zn electrocatalyst, respectively. On the other hand, 0.2 M NaHCO3 produced 494.6 μmol and 176 μmol of HCOOH after 10 min using Sn and Zn electrocatalyst, respectively. Therefore, the work is worthy for single product formation from CO2 and water using inexpensive and efficient electrocatalysts.

Elementary mechanism for photo electroreduction of CO2 to HCOOH.Figure optionsDownload as PowerPoint slide