Accelerating C–C Coupling for CO 2 ‐to‐Ethylene Conversion via Yolk‐Shell Cu 2 O@Ag Catalysts

ABSTRACT Electrochemical CO 2 reduction to ethylene (C 2 H 4 ) is fundamentally hindered by sluggish C–C coupling kinetics and inadequate control over intermediate dynamics. Herein, we propose a synergistic structural and electronic engineering strategy by designing Cu 2 O@Ag yolk‐shell nanostructures (Cu 2 O@Ag YSNs) as efficient tandem electrocatalysts. The yolk‐shell architecture induces a spatial confinement effect that locally enriches *CO intermediates, whereas the precisely tailored Ag‐Cu 2 O hetero‐interface reconfigures the local electronic structure, fundamentally lowering the C–C coupling energy barrier. Driven by this dual synergy, the Cu 2 O@Ag YSNs deliver a peak C 2 H 4 Faradaic efficiency of 36.17% and a partial current density of −10.18 mA cm −2 , significantly outperforming their monometallic counterparts and conventional Cu–Ag composites in both selectivity and durability. Ultimately, this work elucidates the critical role of spatial‐electronic coupling in tandem catalysis, providing a rational design strategy for regulating intermediate dynamics in CO 2 electroreduction.