Cooperative Atomic Palladium Site and Island-Distributed S-Scheme Heterostructure for Photocatalytic C2H6 Production

Abstract

The CO₂ reduction reaction (CO₂RR) to produce C₂ products relies on the synergy between the C₁ generation site and the C–C coupling site within the photocatalytic system. However, yields are often limited by inadequate C₁ precursor production, inefficient multielectron transport, and weak C₁ adsorption at the C–C coupling site. In this study, we developed a highly efficient photocatalytic system that achieved remarkable conversion of CO₂ to C₂H₆ by integrating Pd single atomic sites and island-distributed PdO nanoparticles onto phosphorus-modified BiOCl (PdO/BOCP-Pd₁). This system exhibited a prominent C₂H₆ yield of 215.6 μmol g^–1 h^–1 and a selectivity of 97.5%, maintaining its performance with negligible decay over a minimum duration of 200 h, representing the top-level photocatalytic performance of reported photocatalysts. Both experimental and theoretical results confirm that the Pd₁ site in the PdO/BOCP-Pd₁ catalyst significantly enhances the availability of local CO. Its distinctive S-scheme charge transfer mode promotes the formation of electron-rich PdO sites. Thanks to the superior CO adsorption capacity of PdO, these electron-rich PdO sites can serve as efficient C–C coupling sites after adsorbing CO, ultimately leading to the highly efficient production of C₂H₆. This study provides insight into designing multisite cooperative photocatalysts for superior CO₂RR to C₂ products.