Trifunctional Catalysis via Oxalate Supported Pt−Fe Dual Atoms to Break Site Spatial Restriction in Heterogeneous Catalytic Alkyne Hydrosilylation

Abstract

The development of heterogeneous catalysts for alkyne hydrosilylation is critical, yet it remains limited by spatially confined metal sites that are inadaptable to multiple substrate activation and steric hindrance, leading to low efficiency and poor Markovnikov selectivity for internal and terminal alkynes. This work reports the rational design and facile synthesis of a Pt−Fe dual-atom catalyst that effectively alleviates these spatial constraints and markedly enhances the activity and Markovnikov selectivity for alkyne hydrosilylation. Prepared via a simple and efficient oxalate chelation strategy, the catalyst delivers the upmost 99% yield with a 7-fold higher turnover frequency for internal alkynes and the predominant Markovnikov selectivity for terminal alkynes, along with a good durability. It significantly surpasses Pt and Fe single-atom catalysts as well as commercial and reported Pt-based homogeneous and heterogeneous systems. Mechanistic studies reveal that Pt and Fe atomic centers cooperatively activate silanes and alkynes, and trigger the formation of the α-alkenylsilane intermediate, while oxalate species further assist the hydrogen transfer between the two centers via spillover, thereby accelerating the hydrosilylation process. This work highlights oxalate-based linkers as effective motifs for constructing multinuclear atomic catalysts and provides a general strategy for designing high-performance heterogeneous catalysts for hydrofunctionalization reactions.