Ag/Cu foam catalyst for selective reduction of CO2 to CH3OH at low potential†

Electrocatalytic selective reduction of CO₂ to liquid phase products, particularly methanol, is a promising technique for CO₂ utilization. However, the challenge is daunting because the reduction of carbon dioxide to CH₃OH requires six electron transfer reactions and four protons derived from water. In this study, a complex plating method was employed to modify the surface of Cu foam catalyst with Ag. The electrolyte solution used for CO₂ reduction at a low potential (−0.1 V vs. RHE) was 0.1 M Na₂SO₄. This is the minimum voltage reported for methanol production, with a remarkable Faraday efficiency (FE) of 81.33%. The reduction products of CO₂ in this system included CH₃OH, CH₄, CO and H₂, the impact of silver plating duration on the electrochemical performance of Ag/Cu foam catalyst was examined and a reduction pathway of Ag/Cu foam catalyst in selective electrocatalytic CO₂ was proposed.