Catalytic conversion of CO₂ into multi-carbon products represents a promising route for sustainable carbon utilization, yet its practical realization remains limited by the high energy barrier associated with C–C coupling. Here, we demonstrate that the out-of-plane helical distortion in chiral WSe₂ (CWS), serving as a structural origin of symmetry breaking, induces a pronounced spin-momentum locking effect due to asymmetric spin-orbit coupling (SOC) introduced by helical distortion. This effect subsequently stabilizes the *OCCO intermediate, which markedly lowers the activation energy barrier for C–C coupling. Spin-polarized density functional theory (DFT) calculations incorporating SOC reveal that the helical distortion breaks inversion symmetry and generates an asymmetric spin-dependent potential landscape, producing momentum-locked spin textures and valley-contrasting Berry curvature. These spin-geometric features enable carrier populations near the band edges and induce localized spin polarization at the catalytic interface. At the catalytic interface, this chiral environment enhances *OCCO adsorption through stronger orbital overlap and interfacial charge transfer. Concurrently, out-of-plane lattice distortion facilitates electronic delocalization and spin-matched hybridization between CWS surface and adsorbed state *OCCO, thereby efficiently driving the conversion of *OCCO to the final product. This study establishes a quantum design principle for chiral helical catalysts that harnesses chirality-induced spin polarization to enhance CO₂ conversion into multi-carbon products.

Enantiomeric discrimination plays a crucial role in various scientific domains, including analytical chemistry, chemical biology, pharmaceuticals, and pesticide research. A variety of theoretical frameworks and chiroptical spectroscopic methods, including optical rotation and circular dichroism, have been devised to identify and quantify enantiomers. Generally, circularly polarized light is utilized to determine the absolute configuration and composition of enantiomers. However, these techniques are not suitable for racemic mixtures or substances with minimal optical activity. Herein, we propose that ultraviolet–visible-absorption chiral anisotropy (UV–Vis-ChA) of chiral nanostructured Au particles (CNAPs) can be utilized for enantiomeric discrimination, using amino acids as a model system. The CNAPs, synthesized via a seed-mediated method using chiral glutathione as the symmetry-breaking agent, exhibit a helical nanocubic structure. Upon the addition of amino acid enantiomers to the CNAPs solution, the decrease in the UV–Vis absorbance of CNAPs solution, with varying rates, was induced by enantiomers with different enantiomeric excess (ee) values. The rate constant of absorbance decrease (k_Δ) was proportional to the ee values, regardless of polarity, size, or chromophore type. It is speculated that the UV–Vis-ChA results from the selective aggregation of CNAPs due to the formation of coordination bonds with enantiomers which is driven by their spin polarizations. This work provides a cost-effective, broad-spectrum, and quantitative approach to enantiomeric discrimination.