Lattice strain and electron donation by La in Cu2O promote asymmetric active sites for efficient CO2-to-ethanol conversion.

The electrochemical conversion of CO2 into ethanol, a valuable liquid fuel, remains a great challenge due to the difficulty in steering complex reaction pathways and stabilizing critical oxygenated intermediates on copper-based catalysts. While rare-earth element doping can enhance C2+ production, it typically favors ethylene. Here, we demonstrate that doping lanthanum into Cu2O creates a highly active and stable catalyst for selective CO2-to-ethanol electroreduction. Spectroscopic results combined with electrochemical and theoretical analyses reveal that the incorporated La3+ acts as a potent electron donor, lowering the work function and upshifting the band center of Cu to strengthen CO2/CO adsorption. Simultaneously, the large La3+ ions induce lattice strain to form asymmetric Cu(La)-Cu sites, which uniquely stabilize the *OCCHO intermediate from OCCO configuration. This dual electronic and geometric modulation promotes asymmetric CC coupling with CO bond retention, thereby diverting the pathway from ethylene toward ethanol. The optimized La-Cu2O catalyst achieves high Faradaic efficiency of 43.2% for ethanol and 67.38% for C₂₊ products, with a C2/C1 ratio >10, and exhibits enhanced operational stability by suppressing Cu+ reduction. This work establishes La doping as a distinct strategy for designing CO2RR catalysts targeting multi‑carbon oxygenates.