Synthesis of Pb2O electrocatalyst and its application in the electrochemical reduction of CO2 to HCOOH in various electrolytes

Abstract

The reduction of CO₂ to products electrochemically (RCPE) using synthesized Pb₂O and Co₃O₄ electrocatalysts in various electrolytes was investigated under ambient conditions. The catalyst (Pb₂O) was synthesized electrochemically using an electrodeposition technique. Electrodes were prepared using the synthesized electrocatalysts coated on a graphite plate surface for RCPE. Pb₂O/(graphite plate) and Co₃O₄/(graphite plate) were used as the cathode and anode, respectively, in RCPE. The experiments were conducted at different applied voltages (1.5 to 3.5 V) and time intervals of 5, 10, 15, 20 and 25 min using both carbonates and bicarbonates of sodium and potassium electrolytes separately. Formic acid (HCOOH) was formed for all the applied voltages at different time intervals in the presence of the four electrolytes considered herein. However, higher Faradaic efficiencies were obtained for the bicarbonate based solutions than the carbonates. At 2 V, maximum Faradaic efficiencies of ∼60% and ∼50% for HCOOH were obtained after 10 min of reaction in KHCO₃ and NaHCO₃ electrolyte solutions, respectively.