Synthesis of highly active rGO-supported mono and bi-metallic nanocomposites as catalysts for chemoselective hydrogenation of α,β-unsaturated ketone to alcohol

Herein, highly active reduced graphene oxide (rGO)-supported mono (Au/rGO and Pd/rGO) and bi-metallic (Cu-Au/rGO and Cu-Pd/rGO) nanocomposite (NC) catalysts were synthesized by a simple chemical reduction method. Both mono and bi-metallic NC catalysts were analyzed using different characterization techniques such as field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses. The surface morphology and microstructural results revealed that the mono (Au/rGO and Pd/rGO) and bi-metallic (Cu-Au/rGO and Cu-Pd/rGO) nanoparticles (NPs) were well dispersed on rGO nanosheets through a charge transfer phenomenon between rGO and mono & bi-metallic NPs. Moreover, the catalytic activity performances of newly prepared mono and bi-metallic NC catalysts were studied towards the chemoselective hydrogenation of an alpha,beta-unsaturated ketone to an alcohol. The observed catalytic activity results revealed that the bi-metallic Cu-Pd/rGO NC catalyst showed a higher conversion yield (100%), reusability (upto three cycles), and good selectivity than Cu-Au/rGO as well as mono-metallic (Pd/rGO, Au/rGO) NCs.