Palladium supported on hydrophilic magnetic nanoparticles as a new efficient catalyst in aqueous media

Abstract

Designing efficient hydrophilic catalysts for applying in aqueous media is still a great sustainable processes challenge. In this research, glycerol as a non-toxic and biodegradable chemical was used for preparation of water dispersible magnetic nanoparticles which was applied for stabilization of Pd NPs. Resulting composite (Fe3O4@SiO2-T-G@Pd) was characterized using multiple techniques including FTIR, SEM mapping, TEM, XRD, VSM, and TGA. Hydrophilic property of the Fe3O4@SiO2-T-G@Pd was proved by experiments. This magnetic palladium catalyst showed high catalytic performance in the conversion of nitro compounds to corresponding amines as well as in C-C coupling reactions in aqueous media with high efficiency and selectivity. Using this catalyst and NaBH4 as reducing agent, structurally different nitroarenes were reduced to corresponding amines with very good to excellent yields in aqueous media at room temperature. Furthermore, typical Suzuki-Miyaura coupling reaction of 4-bromoanisole with phenylboronic acid was proceeded very well in aqueous media at 60°C. The magnetically water dispersible catalyst was recycled and reused several cycles in the reduction of nitrobenzene without significant loss in its activity and stability such as confirmed TEM, SEM and XPS analyses.