Palladium nanoparticles decorated on amine functionalized graphene nanosheets as excellent nanocatalyst for the hydrogenation of nitrophenols to aminophenol counterparts

We reported the improved catalytic property of Pd (0) nanoparticles decorated on amine-functionalized graphene nanosheets (Pd/GNS-NH2) for the hydrogenation of nitrophenol derivatives in the presence of NaBH4 at moderate conditions. Pd/GNS-NH2 nanocatalyst was synthesized by the deposition-reduction method. Sundry techniques such as ICP-OES, P-XRD, XPS, TEM, HR-TEM and EDX have been applied to explain the structure and morphology of the Pd/GNS-NH2 nanocatalyst. The results show that the Pd (0) nanoparticles are perfectly dispersed on the surface of the GNS-NH2 support material (d(mean) = 1.38-2.63 nm). The catalytic activity of the Pd/GNS-NH2 nanocatalyst was tested in the hydrogenation of nitrophenol derivatives in water in the presence of NaBH4 as reductant and the excellent activity of nanocatalyst have been detected against 2-nitrophenol, 4nitrophenol, 2,4-dinitrophenol and 2,4,6-trinitrophenol derivatives with 116.8, 65.9, 42.8 and 11.4 min(-1) initial TOF values, respectively. Another important point is that the nanocatalyst has very high reusability performance (at 5th reuse between 71.5 and 91.5%) for the hydrogenation of nitrophenols. Finally, catalytic studies have been carried out at various temperatures to calculate the E-a, Delta H-not equal and Delta S-not equal.