Optimizing water dissociation dehydrogenation process via Sn single atom incorporation for boosting photocatalytic CO2 methanation

Summary

The conversion of CO₂ into value-added methane (CH₄) via light-driven processes represents a promising strategy for mitigating energy scarcity and curtailing CO₂ pollution. However, the intricate reaction kinetics of multiple electron-proton coupling processes remain a significant challenge. During the CO₂ photoreduction process, the promotion of proton production from water dissociation for CH₄ generation has been overlooked. Herein, Co₃O₄ is modified by Sn single atoms to realize selective CH₄ production from CO₂ photoreduction. The introducing of Sn induces generation of oxygen vacancy and adjacent low-valence Co (Co²⁺), which favors CO₂ adsorption and activation by virtue of the reduced steric hindrance and enriched electrons at Co²⁺ sites. Specifically, Sn single atoms serve as H₂O dissociation sites, accelerating the production of protons and reducing the energy barrier of the rate-determining step. Our work endows a guideline for controlling CO₂ photoreduction products' selectivity through the delicate design of active sites in catalysts and reaction kinetics optimization.