Hollow Porous Ag Spherical Catalysts for Highly Efficient and Selective Electrocatalytic Reduction of CO₂ to CO

Electrochemical reduction of CO2 is recognized as a promising way to alleviate the environmental and energy crisis. However, its low efficiency and poor stability restrict the practical application of most conventional electrocatalysts. In this work, a hollow porous silver catalyst is presented for the selective electrocatalytic reduction of carbon dioxide to carbon monoxide. Porous hollow Ag microspheres are synthesized by a very simple and fast method using a spherical Cu2O template. The hollow porous Ag electrocatalysts are capable of electrochemically reducing CO2 to CO with up to 94% Faradaic efficiency as well as excellent stability. The catalytic activity of hollow porous Ag microspheres is about 10 times higher than that of solid Ag for electrochemically reducing CO2 to CO. The high performance of Ag catalysts is attributed to the unique hollow porous structure which provides high electrochemical surface area and intrinsically higher activity in comparison with solid Ag.