▎ 摘　　要

In this study, Pd nanoparticles supported on Metformin modified graphene oxide (GO-Met-Pd) is proposed as a green heterogeneous catalyst. The structural properties of the as-synthesized nanocatalyst were determined by X-ray diffraction (XRD), Fourier transformed infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), wavelength-dispersive X-ray spectroscopy (WDX) and inductively coupled plasma (ICP). Activity of the catalyst was investigated by focusing on the Suzuki-Miyaura coupling reaction and room-temperature reduction of 4-nitrophenol (4-NP), as model reactions. The catalyzed reactions provided high yields of biphenyl compounds through the Suzuki-Miyaura reaction and outlined highly efficient conversion of 4-NP to its reduced form. Moreover, no significant Pd leaching was detected in the reaction solutions and the catalyst could be recovered, at least, 6 times without any considerable loss of its catalytic activity. (C) 2018 Elsevier Ltd. All rights reserved.