Highly efficient Fe3O4@Pd@C3TES catalysts for azide/nitroaromatic hydrogenation and Suzuki–Miyaura cross-coupling: the promotion of nano-porous triethoxypropylsilane as reaction cavities

Abstract

Designing superparamagnetic palladium nano catalysts that combine high catalytic efficiency, versatility across different reactions, and simple synthesis remains a key challenge in advanced catalysis, which requires careful optimization of both surface properties and nanoparticle architecture to achieve both reactivity and stability. Herein, we report a mag-core–shell structured Pd magnetic nano-catalyst (MNC), Fe₃O₄@Pd@C₃TES, that displayed excellent catalytic performance in both hydrogenation of azides/nitroaromatics and Suzuki–Miyaura cross-coupling with broad substrate scope and good functional group tolerance. Compared to other silica coatings, a pore size of 6 nm in C₃TES is key to the catalyst's capability. For a mechanistic study, Fe₃O₄@Pd@C₃TES-catalyzed hydrogenation occurred via an in situ heterogeneous pathway, while for Suzuki–Miyaura coupling, a leaching–redeposition pathway was perceived. In both situations, the modification of alkyl groups and the nano porosity provided reaction cavities for active Pd species, enhancing both the activity and stability of the catalyst.