Synthesis of Sn catalysts by solar electro-deposition method for electrochemical CO2 reduction reaction to HCOOH

The electrochemical conversions of CO2 to valuable products have gained much interest to mitigate the increasing CO2 concentration in the atmosphere. Selective syntheses of differently shaped tin (Sn) catalysts of rod, rectangular sheet, and dendrite structures were reported here using a new solar electro-deposition method, and their catalytic performance was investigated for the electrochemical reduction of CO2 to liquid fuel in an electrolyte solution of CO2 dissolved pure water. The crystal orientation and structural properties of the prepared Sn catalysts were investigated by XRD and SEM analyses. The selective formation of HCOOH on the prepared Sn electrocatalyst was observed with high faradaic efficiency and HCOOH formation rate over the rod shaped Sn catalysts, resulted in a maximum faradaic efficiency of 94.5% at 1.6 V vs Ag/AgCl and a maximum formation rate of about 0.5 mol/gcat h at 2 V vs Ag/AgCl. The present work may open up a new approach for a selective catalyst synthesis of known structural properties for effective CO2 reduction reaction.