One-step synthesis and catalytic properties of porous palladium nanospheres

We report a facile methodology for one-step synthesis of the porous palladium nanospheres (Pd-NSS) using polyallylamine hydrochloride (PAH) as the complex-forming agent and stabilizing agent under mild reaction conditions (35 degrees C). The size, integrity, nature and composition of the Pd-NSS are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-adsorption experiments, energy-dispersive X-ray analysis (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), zeta potential, ultraviolet-visible (UV-vis) spectroscopy and Fourier transform infrared spectroscopy (FT-IR), etc. These spectral studies confirm that the PAH functionalized Pd-NSS are three-dimensionally interconnected porous nanostructures with primary nanoparticles as building blocks. Further experiential investigations show that the particle size of the Pd-NSS can be readily controlled by altering the ratio of PdCl2 to PAH during synthesis, and the Pd-NSS possess high catalytic activity and good stability for the Mizoroki-Heck reaction.