Aggregation-Induced Equidistant Dual Pt Atom Pairs for Effective CO2 Photoreduction to C2H4

The photocatalytic conversion of CO2 into high value-added ethylene (C2H4) is challenging due to the unsuitable active sites and the significant energy barrier associated with the C-C coupling process. Single-atom catalysts are advantageous for their high atom utilization efficiency, yet enhancing C-C coupling efficiency requires strategic engineering of the active site environment. Traditional approaches often result in the random spacing of active atom pairs, which can hinder C-C coupling facilitation. Dual-atom pairs with precise geometrical modulation and well-defined spacing can improve the generation of C2 products and enhance the mechanistic understanding. Herein, we present an equidistant dual Pt atom pair assembly on the Bi3O4Br surface via Pt-TCPP aggregation. Using this strategy, the spacing between neighboring Pt atoms in each atom pair is confined through intermolecular van der Waals forces, and such a geometrically well-defined site significantly facilitates the C-C coupling process. Consequently, the atom pair configuration achieves a C2H4 yield over 8 times higher than that of the single atom structure, with an improved TOF of site enhancement of about 10 times. Our work highlights an effective strategy for fabricating well-defined dual-atom catalysts, offering a promising pathway for efficient CO2 photoreduction to C2H4 by precisely designing the photocatalytic environment.