Carbon‐Supported Dual‐Nickel Atom Catalysts With Stabilized Ni─N ₃ Active Sites for Efficient CO ₂ Electroreduction

ABSTRACT Unsaturated Ni─N ₃ single‐atom catalysts (SACs) have been explored to overcome the conventional Ni─N ₄ structural limitations for electrochemical CO ₂ reduction reaction (eCO ₂ RR). However, their inherently low structural stability has significantly hindered practical applications. Herein, we developed dual‐nickel atom catalysts (Ni‐DACs) to stabilize unsaturated Ni─N ₃ atomic sites by constructing N ₃ Ni─NiN ₃ dual‐atom structures (Ni ₂ ─N ₆ sites) from coal. Theoretical prediction reveals that Ni ₂ ─N ₆ sites exhibit lower energy barriers for *COOH intermediate generation relative to Ni─N ₄ sites and reduce the *CO desorption barriers compared to Ni ₃ ─N ₆ sites, thereby boosting reaction kinetics for CO generation. Aberration‐corrected scanning transmission electron microscopy and synchrotron X‐ray absorption fine structure spectroscopy validate the atomic dispersion of Ni dual‐atom sites. The prepared Ni‐DACs sample achieves the highest Faradaic efficiency for CO (FE _CO ) generation of 98.6% at −0.8 V vs. reversible hydrogen electrode (RHE) and maintains a high FE _CO over 94% from −0.8 to −1.2 V vs. RHE. It also shows a superior CO production turnover frequency as high as 7885 h ⁻¹ even at 1.19 V overpotential, outperforming Ni‐SACs (2615 h ⁻¹ ). This study offers a scalable approach for stabilizing unsaturated Ni─N ₃ SACs to forge a path for their application in eCO ₂ RR.