Selective Oxidation From Toluene to Benzaldehyde via 4 f‐ Orbital Involvement

ABSTRACT Selective oxidation has been greatly challenging for the benzylic C─H bond from toluene to benzaldehyde. In this study, Sm 3+ doped Bi 2 WO 6 (Sm‐BWO) nanosheets are constructed through in situ lattice substitution to establish spatially coupled dual‐active sites with interfacial synergy, enabling a high toluene conversion rate of 8550 µm ol·g −1 ·h −1 with high selectivity toward benzaldehyde (>86%). Mechanistic investigations reveal that Sm‐doping induces oxygen vacancies (O V s) and Bi─O frustrated Lewis pairs (FLPs) for benzylic C─H dehydrogenation. The 4 f orbital from localized Sm enables electron injection into π* antibonding orbitals of O 2 . Orbital coupling between 4 f of Sm and 2 p of O creates a directional oxygen species transfer channel across the interface, delivering activated oxygen species for direct oxygenation of benzyl intermediate to benzaldehyde. The f ‐orbital catalysis demonstrates as a generalizable strategy for orchestrating O 2 activation for C─H functionalization. A unique perspective was provided on selective benzylic C─H oxidation by leveraging the f‐ orbital catalysis via inexpensive light rare earth.