Promoting CO₂ Dynamic Activation via Micro-Engineering Technology for Enhancing Electrochemical CO₂ Reduction

Optimizing the coordination structure and microscopic reaction environment of isolated metal sites is promising for boosting catalytic activity for electrocatalytic CO₂ reduction reaction (CO₂ RR) but is still challenging to achieve. Herein, a newly electrostatic induced self-assembly strategy for encapsulating isolated Ni-C₃ N₁ moiety 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-C₂ N₂ moiety (94.47%, ≈-12.06 mA cm^-2 ), or without hollow structure (92.30%, ≈-5.39 mA cm^-2 ), and high FE_CO of ≈98.41% at 100 mA cm^-2 in 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-C₃ N₁ moiety, which can enrich electron on Ni sites and positively shift d-band center to the Fermi level to accelerate the adsorption and activation of CO₂ molecule 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-CO₂ battery assembled with a peak power density of 2.54 mW cm-^-2 is achieved.