Oxidation-etching induced morphology regulation of Cu catalysts for high-performance electrochemical N2 reduction

Renewable-electricity-driven N-2 reduction is an attractive approach for ambient NH3 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 -0.35V vs reversible hydrogen electrode (RHE) and a large NH3 yield of 2.45x10(-10) mols(-1) cm(-1) at -0.40V 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 20hours.