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 (CH) into high value-added chemicals under ambient conditions. However, the high C-H bond dissociation energy of CH and the absence of well-defined C-H activation sites on catalysts significantly limit the highly efficient conversion of CH toward multicarbon (C) hydrocarbons, particularly ethylene (CH). Herein, we demonstrate a bimetallic design of Ag nanoparticles (NPs) and Pd single atoms (SAs) on ZnO for the cascade conversion of CH into CH 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 CH and the resulting CH, constituting a truly synergistic catalytic system to facilitate the CH generation. This work offers a novel perspective on the advancement of photocatalytic directional CH conversion toward high value-added C hydrocarbons through the subtle design of bimetallic cascade catalyst strategy.