Interfacial influences of variable aminoalkyl chains on catalytical performances of dendritic silica-supported palladium nanoparticles

Abstract

To effectively improve performances of silica-based supported catalysts against the aggregation and leaching of anchored metal nanoparticles, functional interfaces have been naturally introduced between SiO₂ substrates and active matters. Regrettably, when mono-, di- and tri-aminosilanes are utilized as interfacial functional layers, their influences on physicochemical properties and catalytic performances of target catalysts have not been contrasted and revealed up to now. In this work, we attempt to explore these effects by selecting commercial aminosilanes with variable aminoalkyl chains inside (mono-, di- and tri-amino groups as 1 N, 2 N, and 3 N) and dendritic mesoporous silica nanoparticles (DMSNs) as supports. Three types of DMSNs-supported palladium catalysts have been conceived, including DMSNs-1N-Pd, DMSNs-2N-Pd, and DMSNs-3N-Pd. Their morphologies, architectures, compositions of crystal phases, surface functional groups, and loading contents of Pd have been compared and the differences have been accordingly explained. The three materials have potentials to function as photocatalysts. Moreover, catalytical performances have been evaluated by Pd-catalyzed Suzuki coupling reaction as the model to reveal the interfacial effects of 1 N, 2 N, and 3 N. Most importantly, this work can guide researchers to reasonably choose mono-, di- or tri-aminosilane with variable aminoalkyl chain in practical applications.