A covalent organic framework-based route to the in situ encapsulation of metal nanoparticles in N-rich hollow carbon spheres†

Abstract

Covalent organic frameworks doped with metal cations can be used as novel precursors for the in situ encapsulation of metal NPs into N doped hollow carbon spheres. The integration of the hollow structure, N dopant and ultrafine Pd NPs gives the hybrid nanocomposites advanced catalytic performance.

Abstract

Metal nanoparticles (NPs) encapsulated in hollow nanostructures hold great promise for a variety of applications. Herein, we demonstrate a new concept where covalent organic frameworks (COFs) doped with metal cations can be readily used as novel precursors for the in situ encapsulation of metal NPs into N doped hollow carbon spheres (NHCS) through a controlled carbonization process. The obtained Pd@NHCS composites show a significantly enhanced catalytic activity and selectivity in the hydrogenation of nitrobenzene in ethanol and oxidation of cinnamyl alcohol compared with that of the conventional Pd/N–C and commercial Pd/C catalysts. The excellent catalytic performance should be related to the synergism of the porous hollow spheric structure, highly dispersed Pd NPs, and uniform distribution of N dopants on the materials. We believe that this newly developed methodology could be extended to the synthesis of other metal NPs@NHCS composites for a variety of advanced applications.

Notes

†Electronic supplementary information (ESI) available: Experimental details and catalysts characterization. See DOI: 10.1039/c6sc01659f