Boosting Anti-Markovnikov Hydrosilylation Performance with Partially Charged Platinum Single Atoms on Nonreducible γ-Al₂O₃

Constructing thermally durable single-atom catalysts resembling mononuclear homogeneous catalysts for the hydrosilylation industry is usually challenging. Herein, a stable single-atom catalyst with Pt single atoms anchored on a nonreducible and industrially fundamental γ-Al2O3 support (Pt1/γ-Al2O3) was fabricated using atomic layer deposition technology. The catalyst enabled anti-Markovnikov hydrosilylation under room-temperature and solvent-free conditions and exhibited activity exceeding that of the homogeneous Karstedt’s catalyst. The Pt1/γ-Al2O3 catalyst not only afforded a broad substrate scope in high yields, encompassing various alkenes and alkynes, but also exhibited robust stability and recyclability. Extended X-ray absorption fine structure and X-ray absorption near-edge structure analyses confirmed that the Pt atoms were stabilized by bonding with oxo ligands, forming a PtO4 moiety embedded in γ-Al2O3 lattices with coordination geometries resembling those of mononuclear homogeneous catalysts. Density functional theory calculations revealed that the unexpected catalytic performance could be attributed to the partially positively charged and atomically dispersed Pt atoms in the Pt1/γ-Al2O3 catalyst, which arose from metal–support interaction through oxo ligands, resulting in an elevated d-orbital energy and an upshift in the d-band center away from the Fermi level. This electronic effect facilitated the easier dissociation of phenylethyl and promoted its coupling with the dimethylphenylsilyl group on the catalyst surface, ultimately leading to the desired product.