Honeycomb-like nitrogen-doped porous carbon nanosphere encapsulated ultrafine Pd nanoparticles for selectively catalyzing hydrogenation of cinnamaldehyde in water

In this study, a facile method was developed to synthesize honeycomb-like nitrogen-doped porous carbon nanospheres encapsulated ultrafine Pd nanoparticles (Pd/H-NPCNs) by a combination of one-step Friedel-Crafts reaction between carbazole and benzylamine monomers and subsequent in-situ impregnation-pyrolysis reduction strategy. The obtained Pd/H-NPCNs are further treated with H2O2 to remove carbon layer from the surface of metal to produce Pd/H-NPCNs-H2O2 catalyst. Owing to the high surface area, hierarchically porous structure and special honeycomb-like morphology, the Pd/H-NPCNs-H2O2 catalyst shows the excellent catalytic performance in the selective hydrogenation of cinnamaldehyde (CAL) under mild reaction conditions and water as a green solvent.