Smart Design of Small Pd Nanoparticles Confined in Hollow Carbon Nanospheres with Large Center‐Radial Mesopores

Abstract

Although considerable progress has been made with carbon‐based heterogeneous nanocatalysts, great effort is still needed to regulate their structural parameters to further improve their catalytic activities and stabilities. Herein, we have successfully designed and synthesized new composite nanocatalysts composed of porous hollow carbon nanospheres (PHCNs) containing many small Pd nanoparticles (NPs) on their inner surfaces (PHCNs@Pd NPs). Notably, the PHCNs have disordered micropores and large center‐radial mesopores in the shell and craterlike inner surface, and a high density of small Pd NPs are partially confined on the inner surfaces of the PHCNs. Dendrimer‐like mesoporous silica nanospheres (DMSNs) as hard templates play a critical role in the formation of these unique structures. The resulting PHCNs@Pd NP catalyst exhibits high catalytic activity and selectivity as well as good recyclability in the catalytic oxidation of benzyl alcohol to benzaldehyde, and this catalytic performance is attributed to the unique structure of the support coupled with ultradispersed Pd NPs. Moreover, this synthesis strategy may provide some inspiration for the synthesis of advanced composites with complicated nanostructures for various applications.