Ni2O3-around-Pd hybrid on graphene oxide: An efficient catalyst for ligand-free Suzuki–Miyaura coupling reaction

Abstract Ni 2 O 3 -around-Pd hybrid can be fabricated on graphene oxide (Pd–Ni/RGO) by a simple one-pot wet chemical route. These isolated Pd clusters showed significantly improved performance for Suzuki coupling reaction compared to that of pure Pd/RGO, Ni 2 O 3 /RGO, popularly reported Pd/AC, as well as homogeneous PdCl 2 and PdCl 2 (PPh 3 ) 2 . Characterizations disclosed that Ni 2 O 3 plays multiple roles in exfoliating graphene sheets, mediating the size as well as stability of Pd clusters. Pd–Ni/RGO dispersed homogeneously in the aqueous reaction mixture, exhibited high enrichment towards reactants as well as extremely high activity and stability for the Suzuki coupling reaction. The best turnover frequencies of all Pd atoms reached 38,750 h −1 at 80 °C for bromobenzene coupling. It was concluded that the intimate interaction between Ni 2 O 3 nanoparticles and Pd clusters appears to be beneficial for activating the Pd surface for the catalytic cycle.