Bimetallic Single Atom/Nanoparticle Ensemble for Efficient Photochemical Cascade Synthesis of Ethylene from Methane

Light-driven photoredox catalysis presents a promising approach for the activation and conversion of methane (CH₄) into high value-added chemicals under ambient conditions. However, the high C-H bond dissociation energy of CH₄ and the absence of well-defined C-H activation sites on catalysts significantly limit the highly efficient conversion of CH₄ toward multicarbon (C₂₊) hydrocarbons, particularly ethylene (C₂H₄). Herein, we demonstrate a bimetallic design of Ag nanoparticles (NPs) and Pd single atoms (SAs) on ZnO for the cascade conversion of CH₄ into C₂H₄ with the highest production rate compared with previous works. Mechanistic studies reveal that the synergistic effect of Ag NPs and Pd SAs, upon effecting key bond-breaking and -forming events, lowers the overall energy barrier of the activation process of both CH₄ and the resulting C₂H₆, constituting a truly synergistic catalytic system to facilitate the C₂H₄ generation. This work offers a novel perspective on the advancement of photocatalytic directional CH₄ conversion toward high value-added C₂₊ hydrocarbons through the subtle design of bimetallic cascade catalyst strategy.