Promoting CO₂Dynamic Activation via Micro‐Engineering Technology for Enhancing Electrochemical CO₂Reduction

Abstract Optimizing the coordination structure and microscopic reaction environment of isolated metal sites is promising for boosting catalytic activity for electrocatalytic CO₂reduction reaction (CO₂RR) but is still challenging to achieve. Herein, a newly electrostatic induced self‐assembly strategy for encapsulating isolated Ni‐C₃N₁moiety into hollow nano‐reactor as I‐Ni SA/NHCRs is developed, which achieves FE_CO of 94.91% at −0.80 V, the CO partial current density of ≈−15.35 mA cm⁻², superior to that with outer Ni‐C₂N₂moiety (94.47%, ≈−12.06 mA cm⁻²), or without hollow structure (92.30%, ≈−5.39 mA cm⁻²), and high FE_COof ≈98.41% at 100 mA cm⁻²in flow cell. COMSOL multiphysics finite‐element method and density functional theory (DFT) calculation illustrate that the excellent activity for I‐Ni SA/NHCRs should be attributed to the structure‐enhanced kinetics process caused by its hollow nano‐reactor structure and unique Ni‐C₃N₁moiety, which can enrich electron on Ni sites and positively shift d‐band center to the Fermi level to accelerate the adsorption and activation of CO₂molecule and *COOH formation. Meanwhile, this strategy also successfully steers the design of encapsulating isolated iron and cobalt sites into nano‐reactor, while I‐Ni SA/NHCRs‐based zinc‐CO₂battery assembled with a peak power density of 2.54 mW cm−⁻²is achieved.