Supported Bimetallic AuPd Nanoparticles as a Catalyst for the Selective Hydrogenation of Nitroarenes

Abstract

The solvent-free selective hydrogenation of nitrobenzene was carried out using a supported AuPd nanoparticles catalyst, prepared by the modified impregnation method (M_Im), as efficient catalyst >99% yield of aniline (AN) was obtained after 15 h at 90 °C, 3 bar H₂ that can be used without any further purification or separation, therefore reducing cost and energy input. Supported AuPd nanoparticles catalyst, prepared by M_Im, was found to be active and stable even after four recycle experiments, whereas the same catalyst prepared by S_Im was deactivated during the recycle experiments. The most effective catalyst was tested for the chemoselective hydrogenation of 4-chloronitrobenzene (CNB) to 4-chloroaniline (CAN). The activation energy of CNB to CAN was found to be 25 kJ mol^-1, while that of CNB to AN was found to be 31 kJ mol^-1. Based on this, the yield of CAN was maximized (92%) by the lowering the reaction temperature to 25 °C.