Surface Reconstruction on Uniform CuNanodisks Boosted Electrochemical NitrateReduction to Ammonia

The Haber-Bosch (HB) process has provided most of commercialammonia at the expense of high energy consumption and high CO2emission.Nitrate electroreduction is showing great potential as an alternative route for thegreen and scale-up synthesis of ammonia at ambient conditions. However, theperformance has lagged due to lack of efficient electrocatalysts. In this work, wepresent the facile synthesis of uniform Cu nanodisks with exposed (111) facets ashighly active electrocatalyst for electrochemical ammonia synthesis, delivering ahigh ammonia yield of 2.16 mg mg-1cath-1and a maximum Faradaic efficiency of81.1% at-0.5 V versus a reversible hydrogen electrode (RHE). The remarkableactivity is originated from the surface reconstructed triatomic Cu clusters due tothe cathodic deoxygenation process. As a result, the reconstructed surface showsenhanced affinity to the adsorption of nitrate ions which undergo successivebreak of three N-O bonds, followed by subsequent formation of three N-Hbonds tofinally form NH3. The present study provides the feasible preparation of Cu based advanced catalysts and a uniqueinsight into the mechanism of nitrate electroreduction.