Regioselective Doping into Atomically Aligned Core–Shell Structures for Electrocatalytic Reduction of Nitrate to Ammonia

Abstract

AbstractThe electrochemical nitrate reduction reaction (NO3−RR) presents an environmentally friendly approach for efficient NO3− pollutant removal and ammonia (NH3) production, compared to the conventional Haber–Bosch approach. While core/shell engineering has demonstrated its potential in enhancing NO3−RR performance, significant synthetic challenges and limited shell layer modification capabilities impede the exploration of high‐performance NO3−RR core/shell catalysts. Herein, CuCoO/Co(OH)2 core/shell structure via in situ electrochemical activation is synthesized. The catalyst delivers a maximum NH3 Faradaic efficiency (FE) of 94.7% at −0.5 VRHE with excellent durability and selectivity for NH3 over a wide range of potentials in NO3−RR, surpassing the electrocatalytic performance of both undoped shell and core components. The outstanding performance Cu─CoO/Co(OH)2 is ascribed to the enhanced charge transfer, stabilization of key reaction intermediates, and regulation of hydrogen adsorption over Cu‐doped core/shell structure. Furthermore, the assembled Zn−NO3− battery device attains a peak current density exceeding 32 mA cm−2 and an NH3 yield of up to 145.4 µmol h−1 cm−2. The work offers a novel core/shell engineering strategy in electrocatalytic NO3−RR and sheds light on the doping effects on the electrochemical NH3 synthesis.