Simple surface-assisted formation of palladium nanoparticles on polystyrene microspheres and their application in catalysis

A facile and green approach has been developed for fabricating well-dispersed palladium nanoparticles (Pd NPs) supported on the surface of poly(N-vinylpyrrolidone) (PVP)-stabilized polystyrene (PS) microspheres. The strategy harnesses the reducing ability of PVP and the affinity between PVP and Pd NPs to achieve in situ surface-assisted growth of small noble metal NPs on the PS microspheres, without involving any additional stabilizer or reducing agent. The stabilizer-free formation contributes to the superior availability and accessibility of active sites for catalysis. The resulting PS/Pd composite particles have demonstrated excellent catalytic performance in the probe reaction of 4-nitrophenol reduction. As far as we know, this approach has been the first straightforward in situ deposition of Pd NPs on the PS microspheres, obviating surface treatment and the use of an exogenous reducing agent or a stabilizer. Furthermore, it is extendable to the fabrication of other composite systems, PS/Ag composite particles for example.