Plasma‐Assisted Synthesis of Ni‐Doped Cu‐Based Catalyst Shielded by Carbon Overlayer for Ammonia Electrosynthesis

Abstract

Abstract Plasma‐enabled N 2 oxidation coupled with electrocatalytic NO x − reduction (pNOR‐eNO x − RR) represents a highly promising approach for sustainable, scalable, and distributed NH 3 production under mild conditions. However, the eNO x − RR for NH 3 synthesis is hindered by catalyst degradation, which results in low NH 3 selectivity and poor stability. Here, inspired by solid‐state source doping in photolithography, this work reports a rapid plasma shock strategy to build a Ni‐doped Cu‐based catalyst shielded by a carbon overlayer. It demonstrates long‐term stability, maintaining an NH 3 Faradaic efficiency (FE) of 96% for 156 h at a current density of 1000 mA cm −2 . More importantly, this work establishes a continuous‐flow pNOR‐eNO x − RR system using air and water as feedstocks, achieving an NH 3 yield rate of 5.36 mmol h −1 cm −2 with an NH 3 FE of 85%. In situ characterizations and theoretical calculations reveal that the carbon overlayer suppresses electrochemical surface degradation and stabilizes the coexistence of Cu 2 O and Cu during eNO 3 − RR, while Ni doping simultaneously balances the mismatch between NO 3 − adsorption and *H supply and accelerates both processes. This study provides a new approach for designing stable catalysts and offers insights into the pNOR‐eNO x − RR system, paving the way for continuous NH 3 production directly from air and water under ambient conditions.