Atomic Precision CoCu Heterodimers with Pseudo‐D 3h Symmetry Enable Tandem Nitrate Reduction

ABSTRACT The electrochemical reduction of nitrate (eNO 3 RR) to ammonia (NH 3 ) is an efficient method for mitigating nitrate (NO 3 − ) pollutant while offering sustainable NH 3 generation under ambient environments. However, optimizing NO 3 − adsorption on catalytic surfaces and promoting adsorbed hydrogen formation remain challenging. Herein, we introduce pulsed laser irradiation in liquid for the first time to design a metal–metal–ligand‐coordinated CoCu heterodimer catalyst with a pseudo‐D 3h symmetry anchored on nitrogen‐doped graphene oxide (CoCu‐HeD/NGO), enabling a tandem catalytic effect for the eNO 3 RR. The catalyst reaches a remarkable Faradaic efficiency of 91% at −0.4 V vs. RHE and a high NH 3 production rate of 25 mg h −1 cm −2 at −0.5 V vs. RHE. Combined theoretical and in situ spectroelectrochemical analyses reveal that the synergistic interaction among Co and Cu dual sites enhances NO 3 − adsorption, weakens N─O bonds, and facilitates the establishment of Langmuir–Hinshelwood‐type hydrogenation intermediates, steering the tandem reaction pathway toward selective NH 3 formation. Furthermore, a Zn–nitrate battery with a CoCu‐HeD/NGO cathode integrates energy generation and NH 3 synthesis with environmental remediation, delivering 5.26 mW cm −2 power density and stable discharge performance. Practical NH 3 production is verified via Ar stripping–acid‐trapping methods. This work establishes a new paradigm for the rational design of site‐selective electrocatalysts for hybrid energy‐to‐chemical platforms.