Optimizing water dissociation dehydrogenation process via Sn single atom incorporation for boosting photocatalytic CO 2 methanation

The conversion of CO 2 into value-added methane (CH 4 ) via light-driven processes represents a promising strategy for mitigating energy scarcity and curtailing CO 2 pollution. However, the intricate reaction kinetics of multiple electron-proton coupling processes remain a significant challenge. During the CO 2 photoreduction process, the promotion of proton production from water dissociation for CH 4 generation has been overlooked. Herein, Co 3 O 4 is modified by Sn single atoms to realize selective CH 4 production from CO 2 photoreduction. The introducing of Sn induces generation of oxygen vacancy and adjacent low-valence Co (Co 2+ ), which favors CO 2 adsorption and activation by virtue of the reduced steric hindrance and enriched electrons at Co 2+ sites. Specifically, Sn single atoms serve as H 2 O dissociation sites, accelerating the production of protons and reducing the energy barrier of the rate-determining step. Our work endows a guideline for controlling CO 2 photoreduction products’ selectivity through the delicate design of active sites in catalysts and reaction kinetics optimization.