Spatial confinement boosts C–C coupling in brushed Cu/Ag@CuO NWs for CO₂ electroreduction into C₂H₄

Electroreduction of CO₂ into value-added C₂ products holds promise for carbon management and energy sustainability but still suffers from low CO₂ enrichment and poor C₂ product selectivity. Here, we demonstrated an enhanced C-C coupling process to facilitate reaction along the C₂ product pathway, achieved by increasing the local concentrations of the reactant and intermediates through a novel spatial confinement. By tuning the density of CuO nanobrushes in Cu/Ag@CuO NWs, the C-C coupling of *CO into C₂H₄, rather than further hydrogenation to CH₄, can be optimized. This work has demonstrated a novel strategy, involving modulating the confined space and local concentrations of reactant and intermediates, for optimizing the use of desired reaction pathways. This strategy is expected to provide significant guidance for the design of additional novel catalysts and understanding of how to enhance C₂ product selectivity in CO₂ electroreduction.