RhCu Bimetallic Nanoparticles in Hollow Carbon Spheres for Catalytic Halonitrobenzene Chemoselective Hydrogenation

Supported Rh nanoparticles (NPs) exhibit excellent activity for the chemoselective hydrogenation of halonitrobenzenes (HNBs), but their selectivity to aromatic amines is not satisfactory due to the side reaction on the carbon–halogen bonds, and their recycling stability is limited due to the aggregation and the leaching of active component during the long-term usage. Herein, we design a yolk–shell-structured catalyst that consists of RhCu alloy cores and hollow/microporous carbon shells (HCS) to overcome these problems. The obtained RhCu@HCS catalyst with a Rh/Cu ratio of 1:1 showed good activity, selectivity, and stability in the hydrogenation of p-CNB (p-chloronitrobenzene) to produce p-CAN (p-chloroaniline) due to the synergistic effect between Rh and Cu. The protective carbon shells not only prevented the aggregation of metal NPs but also allowed the reactants to diffuse freely across the shells. Therefore, our research provides a general strategy to design highly efficient and stable hydrogenation catalysts.