Dislocation‐Rich Ag Realizing Selective Carbon Dioxide Electroreduction in Strong Acid

Abstract Acidic electrocatalytic CO 2 reduction is a highly desirable way to overcome the intrinsic limitations in alkaline and neutral electrolytes, such as carbonate formation and large energy loss. However, the selectivity of carbon‐based products in such proton‐rich systems is compromised by the competing hydrogen evolution reaction. Here, a silver (Ag) catalyst rich in dislocation defects (dislocation‐Ag) is designed, achieving a CO Faradaic efficiency of >95% at high current density in the strong acid electrolyte in the membrane electrode assembly (MEA). The CO Faradaic efficiency maintains above 90% over 16 h of operation at 100 mA cm −2 . Experimental findings suggest that the lattice distance of dislocation areas on the Ag surface is compressed from 0.241 to 0.198 nm, which enhances the adsorption of CO 2 and leads to enhanced CO formation.