One-pot synthesis of Pt@Sn core-shell nanocatalysts for the hydrogenation of halonitrobenzene to produce haloaniline with ultra-high selectivity

Abstract

Pt nanocatalysts exhibits superior activity towards the hydrogenation reaction of halonitrobenzenes (HNBs), but the selectivity to the valuable product haloanilines (HANs) is always poor due to the unavoidable dehalogenation process. In this study, we find that coating a thin Sn layer on Pt nanoparticles (NPs) could improve not only the hydrogenation activity but also the selectivity to HANs. These core–shell structured Pt@Sn NPs with different Sn shell thickness were synthesized by one-pot reduction, and their catalytic performance in the hydrogenation reaction of p-chloronitrobenzene to p-chloroaniline could be effectively regulated by the Pt/Sn ratio. The catalyst with a Pt/Sn ratio of 5/1 achieved the highest p-chloronitrobenzene conversion (96.5 %) and excellent selectivity to p-chloroaniline (97.9 %). The kinetic study and H2-TPD analysis indicated that the Sn species on Pt could facilitate the adsorption of p-chloronitrobenzene and the dissociation of H2. The designed Pt@Sn core–shell nanocatalysts are applicable to a wide range of hydrogenation reactions.