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.

Angew. Chem. Int. Ed. 2026, e7848056 https://doi.org/10.1002/anie.7848056