Effect of solid polymer electrolyte on electrochemical reduction of CO2

This paper reports a preliminary investigation on electrochemical reduction of carbon dioxide. Electrochemical reduction of CO2 was studied in a reactor using different solid polymer electrolytes. Cast Nafion membrane and SPEEK were developed and used as cationic solid polymer electrolyte whereas alkali doped PVA and (Amberlyst)/SPEEK composites were developed and used as anionic solid polymer electrolyte. The prepared solid polymer electrolytes were characterized for thickness, thermal stability, ionic conductivity, and mechanical strength. The electrodeposited copper on porous carbon paper was used as cathode whereas Pt/C on the carbon paper was used as anode. The products formed after the electrochemical reduction of carbon dioxide was analyzed by gas chromatography and high performance liquid chromatography. Mainly formic acid (HCOOH), methanol (CH3OH), formaldehyde (HCHO), carbon monoxide (CO), and methane (CH4) were evolved as the products of the ERC apart from the undesired hydrogen gas as a by-product.

► An electrochemical reactor was developed for continuous ERC in gas phase.
► The reactor was used with different solid electrolytes.
► Using cationic electrolyte, CH3OH, HCHO, CO, and CH4 were formed as products.
► Using anionic electrolyte, HCOOH and CO were formed as products.
► The preliminary study was encouraging and electrolytes have strong effects on ERC.