Facile synthesis of palladium nanoparticles on hierarchical hollow silica spheres and its catalytic properties in Suzuki-reaction

A novel well-dispersed Pd@HHSS catalyst was synthesized by reduction of Pd(OAc)2 immobilized on HHSS we reported. When the ratios of Pd/SiO2 were 5 : 100 and 10 : 100, the Pd nanoparticles size was about 5–10 nm. The Pd@HHSS catalyst (Pd/SiO2 = 10 : 100) showed high catalytic activity in Suzuki-reaction with yields of 91–99% and the catalyst is reusable after four successive cycles without obvious loss of catalytic activity.