Orbital-Selective Electronic Tuning of MoS2 via Molecular Intercalation for Efficient Nitroarene Hydrogenation

Abstract The catalytic activity of layered transition-metal dichalcogenides is fundamentally constrained by the limited intrinsic reactivity of their edge sites. Conventional strategies address this limitation by increasing the number of exposed sites, but directly enhancing the reactivity of each individual site remains an elusive goal. Here, we demonstrate that intercalation chemistry can overcome this trade-off by tuning the electronic structure of active sites without altering their density. Small amide molecules intercalated into the van der Waals gap of MoS2 nanoflowers selectively redistribute electrons among the Mo 4d orbitals at sulfur vacancy sites. This orbital-level modulation shifts the d-band center upward and populates the e′ orbitals (dxz and dyz), which serve as the primary channels for electron donation to both hydrogen and the nitro substrate. The resulting enhancement of the intrinsic basicity and hydrogen activation capacity of the Mo centers leads to a near-doubling of catalytic conversion in chemoselective nitroarene hydrogenation while preserving over 99% selectivity. This work establishes molecular intercalation as a generalizable strategy for engineering the intrinsic activity of layered catalysts through orbital-selective electronic tuning.