TY - JOUR
T1 - Zn-Fe pair sites catalyst for highly selective photocatalytic oxidation of methane to formaldehyde
AU - Yu, Shixuan
AU - Fan, Shiying
AU - Duan, Jun
AU - Zhang, Dongke
AU - Li, Xinyong
N1 - Publisher Copyright:
© 2024
PY - 2025/5/15
Y1 - 2025/5/15
N2 - Efficient methane photooxidation into formaldehyde in H2O under mild conditions lies in C-H bond activation and intermediates coupling. Here, we report a Zn-Fe pair sites (Zn-Fex PS) photocatalyst to polarize the CH4 molecules on Zn+-O-sites and facilitate the coupling of *CH3 and *OH on Fe sites. Various in situ investigations confirm that the Zn-Fe0.2 PS promotes the generation of *CH3 and *OH. The theoretical calculations reveal that the local charge density accumulation on Zn and O atoms significantly strengthens Zn+-O- sites polarization, lowering the energy barrier for *CH3 formation from 0.87 eV to 0.36 eV. Moreover, a strong d-σ hybridization between *CH3 and Fe reduces C-H bonds steric hindrance, enhancing the coupling of *CH3 and *OH. Accordingly, the HCHO productivity over Zn-Fe0.2 PS reaches 2660.44 μmol·g−1 with a remarkable selectivity of 95.89 %. This study broadens the scope for designing cost-effective photocatalysts to selectively oxidize CH4 into value-added oxygenates.
AB - Efficient methane photooxidation into formaldehyde in H2O under mild conditions lies in C-H bond activation and intermediates coupling. Here, we report a Zn-Fe pair sites (Zn-Fex PS) photocatalyst to polarize the CH4 molecules on Zn+-O-sites and facilitate the coupling of *CH3 and *OH on Fe sites. Various in situ investigations confirm that the Zn-Fe0.2 PS promotes the generation of *CH3 and *OH. The theoretical calculations reveal that the local charge density accumulation on Zn and O atoms significantly strengthens Zn+-O- sites polarization, lowering the energy barrier for *CH3 formation from 0.87 eV to 0.36 eV. Moreover, a strong d-σ hybridization between *CH3 and Fe reduces C-H bonds steric hindrance, enhancing the coupling of *CH3 and *OH. Accordingly, the HCHO productivity over Zn-Fe0.2 PS reaches 2660.44 μmol·g−1 with a remarkable selectivity of 95.89 %. This study broadens the scope for designing cost-effective photocatalysts to selectively oxidize CH4 into value-added oxygenates.
KW - C-H bond
KW - D-σ orbital hybridization
KW - Intermediates coupling
KW - Polarized surface
KW - Selective photocatalytic oxidation of methane
KW - Zn-Fe pair sites
UR - http://www.scopus.com/inward/record.url?scp=85211758765&partnerID=8YFLogxK
U2 - 10.1016/j.apcatb.2024.124930
DO - 10.1016/j.apcatb.2024.124930
M3 - Article
AN - SCOPUS:85211758765
SN - 0926-3373
VL - 365
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
M1 - 124930
ER -