Confinement Reconstruction Unlocks Stable Ru Single Atom-Doped IrO _<i>x</i> Anodes for Long-Term High-Rate CO ₂ Electrolysis

IrO2 is a commonly employed anode catalyst for CO2 electrolysis in membrane electrode assembly (MEA) systems. However, under high current densities, its structural reconstruction leads to activity loss and stability degradation, limiting the industrial viability of CO2 electrolysis. Herein, we demonstrated a confinement reconstruction strategy to precisely regulate the structural evolution during electrolysis. Ethylene glycol serves as a structural modulator, protecting the catalyst surface, suppressing soluble species formation, and promoting ordered structural evolution. Single-atom Ru acts as a stability enhancer, forming robust Ir–O–Ru bridging structures that facilitate an ordered transformation from a 4-fold [RuO4]/[IrO4] to a 6-fold symmetry [RuO6]/[IrO6] octahedral framework, thereby enhancing structural rigidity and long-term stability. As a result, in MEA-based CO2 electrolysis, the catalyst achieves a stable operation at 200 mA cm–2 for 480 h, maintaining a CO selectivity above 80%. Theoretical calculations further elucidate that the enhanced stability originates from the suppression of oxygen vacancy formation, making the lattice-oxygen-mediated mechanism (LOM) potentially less favorable. This work provides insights into the structural evolution of the OER catalysts under high-current-density conditions, paving the way for large-scale CO2 electrolysis commercialization.