Synergistic <i>t</i> _2g ‐to‐π <i>*</i> Electron Transfer and Nanotube Engineering in Spinal Catalysts for Ultra‐Efficient Chloride Evolution

Abstract

Abstract Facing the massive energy consumption of over 200 TWh y −1 of chlor‐alkali industry, developing high‐activity and durable non‐precious CER (chlorine evolution reaction) catalysts is urgently needed to address the high overpotentials and suppress the dissolution high‐valance metal species. Herein, a carbon quantum dots functionalized trimetallic Fe/Co/Ni spinel oxide nanotube architecture (FCNO@CQDs) is constructed, featuring t 2g ‐to‐π* π‐backbonding for dramatically enhanced CER activity and stability. The reverse electron flow from Co d ‐obritals to the vacant CQDs’ π* orbitals can upshift the d‐band center for enhanced intermediate adsorption, while stabilizing high‐valent Co centers via increased bond order. Meanwhile, the open nanotube architecture facilitates rapid mass transfer and efficient Cl 2 desorption, validated by fluid dynamics simulations and in situ microscopic analysis. Electrochemically, FCNO@CQDs achieves an ultralow overpotential of 174 mV at 500 mA cm −2 and exceptional selectivity of 98.8%–99.7% across a broad potential range, outperforming commercial Ru/Ir‐based dimensionally stable anodes (DSA). Mechanistic studies reveal a dynamic transition from the Volmer–Heyrovský pathway to a hybrid Volmer–Heyrovský and Tafel mechanism under high Cl* coverage ( θ Cl ∼72%), enabling rapid kinetics. By bridging molecular orbital theory with nanoscale architecture design, FCNO@CQDs provides a valuable strategy for optimizing cost‐effective, high‐performance CER catalysts.