Balancing *CHO/*CO Intermediate Flux via Carbonyl-Hydroxyl Motif Synergy Enables High-Selectivity Ethanol Electrosynthesis from Dilute CO _<b>2</b>

The electrochemical CO 2 reduction reaction (CO 2 RR) to ethanol represents a sustainable avenue to close the carbon cycle and produce renewable fuels, yet challenges persist in achieving high selectivity and activity under industrially relevant dilute CO 2 streams. Herein, we realize an efficient ethanol electrosynthesis by coating Cu catalysts with β-hydroxy ketone-based covalent organic polymers (COP CO+OH ), which not only activate CO 2 but also balance the *CHO/*CO flux at the catalyst–electrolyte interface. The COP CO+OH coated Cu NPs (Cu+COP CO+OH ) exhibits unprecedented FE EtOH of 54.2% in 0.5 M KHCO 3, with a partial current density of 121.3 mA cm –2 . Crucially, using a dilute CO 2 feedstock (20% CO 2 ), it retains ∼40.8% FE EtOH, circumventing energy-intensive CO 2 purification. Through systematic experimental characterizations and density functional theory (DFT) calculations, we elucidate a unique organic motif synergy: carbonyl groups serve as CO 2 activation centers, while adjacent hydroxyl groups boost *H supply for *CO protonation to *CHO intermediates. This unique synergy enables a balanced *CHO/*CO flux, thereby creating an optimal environment favoring asymmetric *CHO–*CO coupling and preferentially stabilizing the *CHCOH intermediate toward ethanol production. Our investigations establish a universal design paradigm to bypass scaling relations in CO 2 RR through organic motif synergy, offering atomistic insights into steering complex reaction networks in CO 2 electroreduction.