CuAu alloy nanoclusters modified CeO2 for efficient ethylene synthesis from dilute CO2 via artificial photosynthesis

The efficient synthesis of C 2 fuels via artificial photosynthesis confronts persistent challenge in dilute CO 2 environments. To address this, we engineered a photothermal catalyst incorporating spatially confined Cu/Au alloy nanoclusters on CeO 2 nanorods. The design establishes an atomically precise Ce − O − Au − Cu charge cascade, where directional photothermal energy transfer governs the C − C coupling pathway. Mechanistic studies reveal that Cu sites within the Cu/Au alloy enhance Au-driven localized surface plasmon resonance (LSPR), broadening the spectral response while accelerating hot electron transfer for CO 2 activation. Simultaneously, adjacent Cu sites stabilize co-adsorbed *CO intermediates, directing C − C coupling to form the key *OCCO intermediate, while the Ce − O − Au interface mediates hole-transfer-driven H 2 O oxidation predominantly at Au centers. Integrated theoretical calculations and in situ DRIFTS confirm the kinetic and thermodynamic superiority of the *OCCO pathway over both the *CHO pathway and CO desorption. Under concentrated solar irradiation, this catalyst achieves a C 2 H 4 yield of 110.45 µmol·g −1 ·h −1 (a 20.2-fold increase over non-concentrated conditions), with C 2 selectivity rising from 0% to 78%. Solar-to-chemical conversion (STC) efficiency increases 13.3-fold to 1.25‰. This work elucidates the atomistic mechanism of photothermal coupling-driven directional C − C coupling, providing a generalizable design strategy for efficient carbon–neutral fuel synthesis.