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 4 ) into high value-added chemicals under ambient conditions. However, the high C-H bond dissociation energy of CH 4 and the absence of well-defined C-H activation sites on catalysts significantly limit the highly efficient conversion of CH 4 toward multicarbon (C 2+ ) hydrocarbons, particularly ethylene (C 2 H 4 ). Herein, we demonstrate a bimetallic design of Ag nanoparticles (NPs) and Pd single atoms (SAs) on ZnO for the cascade conversion of CH 4 into C 2 H 4 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 4 and the resulting C 2 H 6 , constituting a truly synergistic catalytic system to facilitate the C 2 H 4 generation. This work offers a novel perspective on the advancement of photocatalytic directional CH 4 conversion toward high value-added C 2+ hydrocarbons through the subtle design of bimetallic cascade catalyst strategy.