Asymmetrically Coordinated Ni‐Based Single‐Atom Catalyst Enables Ultra‐Wide Potential Window for Ampere‐Level CO ₂ Electroreduction

ABSTRACT

Conventional Ni–N ₄ single‐atom catalysts (SACs) hold great promise in sustainable energy conversion and storage, but suffer from weak ^* COOH adsorption and narrow potential windows during CO ₂ electroreduction (CO ₂ RR). To address this limitation, herein we report an asymmetric Ni–N ₃ O ₁ SAC prepared via an oxygen‐mediated spatial confinement pyrolysis strategy. Theoretical calculations predict that this unique asymmetric coordination can effectively lower the ^* COOH formation energy, promote the interaction between the catalyst and ^* COOH, and suppress the competing hydrogen evolution reaction in CO ₂ RR. The prepared Ni–N ₃ O ₁ SAC features a distorted planar quadrilateral structure and demonstrates exceptional performance in CO ₂ ‐to‐CO conversion, with a maximum turnover frequency of 207 700 h ⁻¹ , a maximum CO partial current density of 810 mA cm ⁻² , and CO Faradaic efficiency of ≥ 99% over an ultra‐wide potential window of 2100 mV (−0.3 to −2.4 V vs. reversible hydrogen electrode) in a flow cell. A combination of in situ spectroscopic measurements verifies the reversible structural evolution and robust stability of the Ni–N ₃ O ₁ SAC under CO ₂ RR conditions, as well as the strengthened ^* COOH formation and accelerated CO ₂ activation kinetics. This work provides a feasible route for designing and synthesizing high‐performance asymmetrically coordinated SACs toward industrial CO ₂ ‐to‐CO conversion.