Oxidation‐etching induced morphology regulation of Cu catalysts for high‐performance electrochemical <scp>N₂</scp> reduction

Abstract Renewable‐electricity‐driven N 2 reduction is an attractive approach for ambient NH 3 synthesis, but active electrocatalysts are needed to enable the N 2 reduction reaction. Monolithic electrodes with active components anchored on conductive supports provide many advantages like structural stability, large surface area, and low electrical resistance. Here, a novel “oxidation‐etching” strategy is proposed to carve the surface of Cu foam into structures of particles, cubes, and sheets for N 2 reduction electrocatalysis. The optimal catalyst achieves a Faradic efficiency as high as 18% at −0.35 V vs reversible hydrogen electrode (RHE) and a large NH 3 yield of 2.45 × 10 −10 mol s −1 cm −1 at −0.40 V vs RHE in 0.1 M HCl. Notably, it also shows superior long‐term electrochemical durability, with the preservation of electro‐activity for at least 20 hours. image