Apo-ferritin-Caged Pt Nanoparticles for Selective Hydrogenation of p‑Chloronitrobenzene

Reducing halogenated nitrobenzenes to the corresponding halogenated anilines is a critical process in the production of chemical industries. However, commonly used metal catalysts often require high temperatures and pressurized hydrogen during synthesis and catalysis and are prone to dehalogenation reactions with low selectivity of the reaction. Here we synthesize size-controlled (1.8–3 nm) apo-ferritin-caged Pt nanoparticles at room temperature. The catalysts can efficiently convert p-chloronitrobenzene to p-chloroaniline at 50 °C for 30 min and effectively inhibit the dechlorination reaction with a selectivity of up to 99%; the TOF (22.8 min^–1) is nearly ten times higher than that of the unloaded platinum nanocatalyst. In addition, the catalysts also show a selectivity higher than 90% for another halogenated nitrobenzene. The TEM and XPS results reveal that the unique size effect and the electronic effect of the catalyst due to the interaction between apo-ferritin and platinum are significant reasons for its performance enhancement, which also provides some theoretical basis for the rational design of protein-based metal nanocatalysts.