Electrochemical reduction of CO2 to formate in aqueous solution using electro-deposited Sn catalysts

Abstract

Carbon dioxide as an abundant carbon resource can be used for the production of useful chemicals through electrochemical conversion. Catalyst is a key element for CO2 electrochemical reduction, which determines the crucial factors in the process. In this paper, a series of Sn catalytic electrodes were prepared using electro-deposition method with controlled current density at room temperature, and applied to the electrochemical reduction of CO2. The experimental results showed that the deposited Sn catalysts exhibited a crystal pattern of the (101) and (112) faces and the thickness of deposited layer varied with the deposition current density. The activity of these electrodes was determined in H-type and 3-elelctrode system, and the reduction product was quantitatively analyzed by ion chromatography. The optimized deposition current density for Sn fabrication was found to be 15mAcm−2, on which the Faradaic efficiency of CO2 conversion was over 91% at −1.4V vs. SCE.