Single‐Atom Pt Anchored Polyoxometalate as Electron‐Proton Shuttle for Efficient Photoreduction of CO2 to CH4 Catalyzed by NiCo Layered Doubled Hydroxide

Abstract The crucial role of active hydrogen (H*) in photocatalytic CO 2 methanation has long been overlooked, although recently, accelerating proton‐coupled electron transfer (PCET) processes to enhance CH 4 productivity and selectivity has garnered significant attention. Herein, a single‐atom Pt‐anchored H 3 PMo 12 O 40 (Pt 1 ‐PMo 12 ) is applied as an efficient proton–electron shuttle to facilitate the photocatalytic performance of NiCo layered double hydroxide (NiCo‐LDH). The resultant Pt 1 ‐PMo 12 @NiCo‐LDH exhibited superior CH 4 productivity (723 µmol g −1 h −1 ) with CH 4 selectivity of 82.3%, showcasing a 24.9 times productivity enhancement over NiCo‐LDH (29 µmol g −1 h −1 ). Systematic investigations revealed that abundant H* is generated by the dissociation of H 2 O on Pt 1 sites and stored within Pt 1 ‐PMo 12 . Subsequently, the multiple H* rapidly migrated from Pt 1 ‐PMo 12 to the catalytic sites on NiCo‐LDH by the engineered strong Mo─O─Ni/Co bonds, thereby significantly expediting the PCET process. The in situ DRIFTS and theoretical calculations elucidated that the Pt 1 ‐PMo 12 decreased the energy barrier for *CO protonation to *CHO (0.38–0.18 eV) and optimized the rate‐determining step of *CH 3 to *CH 4 (0.64 eV), thus promoting highly active and selective CH 4 generation. This work provided novel insights into achieving efficient photocatalytic CO 2 methanation by modulating the fast generation and transport of active H*.