Nearly 100% selective and visible-light-driven methane conversion to formaldehyde via. single-atom Cu and Wδ.
Nat Commun
; 14(1): 2690, 2023 May 10.
Article
em En
| MEDLINE
| ID: mdl-37165020
ABSTRACT
Direct solar-driven methane (CH4) reforming is highly desirable but challenging, particularly to achieve a value-added product with high selectivity. Here, we identify a synergistic ensemble effect of atomically dispersed copper (Cu) species and partially reduced tungsten (Wδ+), stabilised over an oxygen-vacancy-rich WO3, which enables exceptional photocatalytic CH4 conversion to formaldehyde (HCHO) under visible light, leading to nearly 100% selectivity, a very high yield of 4979.0 µmol·g-1 within 2 h, and the normalised mass activity of 8.5 × 106 µmol·g-1Cu·h-1 of HCHO at ambient temperature. In-situ EPR and XPS analyses indicate that the Cu species serve as the electron acceptor, promoting the photo-induced electron transfer from the conduction band to O2, generating reactive â¢OOH radicals. In parallel, the adjacent Wδ+ species act as the hole acceptor and the preferred adsorption and activation site of H2O to produce hydroxyl radicals (â¢OH), and thus activate CH4 to methyl radicals (â¢CH3). The synergy of the adjacent dual active sites boosts the overall efficiency and selectivity of the conversion process.
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MEDLINE
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En
Ano de publicação:
2023
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Article