Porous carbon‐supported Ag catalysts enable high‐current‐density CO₂ electroreduction to CO with enhanced mass transport

Silver nanoparticles are typically utilized for the electrochemical reduction of CO 2 to CO, which usually undergo aggregation and deactivation during the reaction. In this study, four types of carbon black with distinct specific surface areas were used to fabricate carbon‐supported silver catalysts, aiming to enhance the dispersion of silver nanoparticles. It has been found that the ECP‐600JD sample has the most‐developed porous structure and the largest specific surface area, and the resulting carbon‐supported silver catalyst (Ag/ECP‐600JD) has the most homogeneous and the smallest particle size. In an electrolytic cell of membrane electrode assembly, the Ag/ECP‐600JD can deliver a maximum current density of 524 mA·cm −2 at 3 V with a Faradaic efficiency of 74% at 200 mA·cm −2 . CO 2 adsorption tests and simulation calculations have shown that Ag/ECP‐600JD has the highest CO 2 enrichment efficiency and the fastest CO 2 mass transfer rate.