Boosting Electrocatalytic Nitrate‐to‐Ammonia via Tuning of N‐Intermediate Adsorption on a Zn−Cu Catalyst

Abstract The renewable‐energy‐powered electroreduction of nitrate (NO 3 − ) to ammonia (NH 3 ) has garnered significant interest as an eco‐friendly and promising substitute for the Haber–Bosch process. However, the sluggish kinetics hinders its application at a large scale. Herein, we first calculated the N‐containing species (*NO 3 and *NO 2 ) binding energy and the free energy of the hydrogen evolution reaction over Cu with different metal dopants, and it was shown that Zn was a promising candidate. Based on the theoretical study, we designed and synthesized Zn‐doped Cu nanosheets, and the as‐prepared catalysts demonstrated excellent performance in NO 3 − ‐to‐NH 3 . The maximum Faradaic efficiency (FE) of NH 3 could reach 98.4 % with an outstanding yield rate of 5.8 mol g −1 h −1 , which is among the best results up to date. The catalyst also had excellent cycling stability. Meanwhile, it also presented a FE exceeding 90 % across a wide potential range and NO 3 − concentration range. Detailed experimental and theoretical studies revealed that the Zn doping could modulate intermediates adsorption strength, enhance NO 2 − conversion, change the *NO adsorption configuration to a bridge adsorption, and decrease the energy barrier, leading to the excellent catalytic performance for NO 3 − ‐to‐NH 3 .