Janus Au/CoFe Hetero‐Domain Alloy Catalysts for Photo‐Driven CO ₂ Hydrogenation to Light Olefin

ABSTRACT Photothermal catalytic conversion of CO ₂ to light olefins is an attractive route for sustainable carbon valorization, yet remains challenged by limited selectivity arising from competing hydrogenation pathways. Here, we develop a ZnO‐supported AuCoFe trimetallic catalyst with precisely engineered Janus‐type hetero‐domain alloy structures, enabling photothermal CO ₂ hydrogenation with a CO ₂ conversion of 26.2% and a C ₂ ‐ ₄ olefin selectivity of 51.5%, corresponding to an olefin yield of 1.82 mmol g ⁻¹ h ⁻¹ . Structural and spectroscopic analyses combined with density functional theory calculations identify a Janus‐type Au/CoFe hetero‐domain alloy, in which spatially differentiated yet electronically coupled domains enable distinct catalytic functions: Au‐rich domains facilitate photothermal CO ₂ activation and C ₁ intermediate formation via enhanced charge excitation and transfer, while CoFe‐rich domains favor C─C coupling and chain growth. This work provides a practical strategy for improving selectivity for photothermal catalysts that couple compositional heterogeneity with electronic structure modulation, enabling efficient and selective CO ₂ conversion to higher‐value olefins.