Orientation-Entropy-Mediated Derivative Cu Sites for Selective CO₂ Electroreduction to Ethylene

Electrocatalytic conversion of CO₂ to ethylene (C₂H₄) provides a sustainable route for decarbonized chemical manufacturing. Cu-based catalysts are uniquely capable of driving the C-C coupling essential for C₂H₄ formation, yet their practical implementation is limited by uncontrollable dynamic reconstruction that deteriorates both selectivity and stability. Here, we develop an orientation-entropy-mediated regulation strategy to programmatically direct the structural evolution of Cu₂O toward highly active sites for C₂H₄ electrosynthesis. Remarkably, the medium-entropy Cu₂O catalyst achieves a high C₂H₄ Faradaic efficiency of ∼75% at an industrial-level current density of 400 mA cm^-2 and operates stably for over 80 h. Operando spectroscopy combined with experimental analysis reveals that entropy-regulated Cu sites establish an optimized kinetic balance between C-C coupling and competing *CO hydrogenation, thereby promoting the energetically preferred formation of the key *CO-*COH intermediate. Preliminary techno-economic analysis projects an additional profit of $566 per ton of C₂H₄, and life-cycle assessment demonstrates an overall ∼42% reduction in environmental impact compared to conventional production routes.