Selective electrochemical reduction of CO₂ to ethanol via atomic-level Pd-incorporated cu alloy catalysts under industrially relevant conditions

The electrochemical reduction of CO 2 (CO 2 RR) to ethanol represents a key strategy for sustainable fuel production; however, achieving high selectivity toward ethanol under industrially relevant current densities remains a formidable challenge. Here, we report a pulse-electrodeposited Cu Pd alloy catalyst with atomic-level Pd incorporation into a face-centered cubic Cu lattice, which dramatically enhances ethanol formation while suppressing ethylene production. At 400 mA cm −2 , the optimized Cu 96 Pd 4 catalyst delivers a Faradaic efficiency of 57 % for ethanol, with ethylene suppressed below 3 %, corresponding to a ∼ 43-fold increase in ethanol-to-ethylene selectivity compared to pure Cu. Structural and compositional analyses confirm uniform Pd distribution without phase segregation. Operando infrared spectroscopy reveals a Pd-induced shift in *CO adsorption from linear to bridge-bound configurations, which correlates with enhanced C C coupling and ethanol selectivity. Complementary density functional theory (DFT) calculations indicate that Pd selectively destabilizes C1-site hydrogenation of *CH 2 CHO while favoring C2-site protonation, thereby steering the pathway toward ethanol. This work establishes a direct correlation between atomic-scale alloying, intermediate adsorption geometry, and product distribution, offering a rational strategy for engineering CO 2 RR catalysts with enhanced selectivity under practical operating conditions. Ethanol and ethylene production pathway on Cu and CuPd. • Atomic-level Pd incorporation in Cu enables selective CO₂-to-ethanol conversion. • Ethanol Faradaic efficiency reaches 57 % with ethylene suppressed below 3 %. • Operando SEIRAS reveals bridge-bound CO correlates with ethanol selectivity. • DFT shows Pd promotes C2-site protonation and inhibits C1 hydrogenation. • Catalyst shows stable ethanol production at 300 mA cm −2 over 12 h electrolysis.