Lattice Chirality in Copper Oxide Nanoparticles Biases C−C Coupling Selectivity in CO 2 Electroreduction

ABSTRACT Precise control over reaction pathways and product selectivity is critical for advancing electrochemical CO 2 reduction reaction (CO 2 RR). Traditional strategies for promoting multicarbon production mainly rely on compositional tuning and architecture optimization. Here we report lattice chirality as a structural feature that biases reaction selectivity. As a proof of concept, chiral CuO nanoparticles were synthesized through thermal conversion of enantiopure Cu‐Cysteine precursors, producing lattice‐distorted nanoparticles while preserving the same crystal phase, morphology, and particle size as the achiral counterpart, which lacks lattice distortion. In CO 2 RR, the chiral‐derived nanostructures suppress the hydrogen evolution reaction and promote multicarbon formation, increasing the C 2+ /C 1 product ratio by up to 68.5% relative to the achiral counterpart. In situ spectroscopy combined with density‐functional theory calculations indicates that lattice chirality modulates the initial CO 2 activation and alters the population and evolution of surface intermediates (e.g., *CO and *OCCO species), favoring C−C coupling toward C 2+ products. Furthermore, lattice distortion increases the energetic cost of oxygen removal, contributing to slower reduction and altered structural evolution of the catalysts during operation compared with achiral counterparts. These results demonstrate that lattice chirality in CuO precatalysts biases reaction pathway selectivity in CO 2 RR, highlighting a potential parameter to modulate chemoselectivity in related multielectron catalytic reactions.