Redox-induced in situ formation of Pd nanoparticles on surfaces of Fe3O4/PANI core/shell hybrids as high-performance catalysts for Suzuki cross-coupling reactions

Fe3O4/polyaniline (PANI)/Pd nanoparticles as supported catalysts with high recyclability and durability have been developed. Fe3O4/PANI as reactive magnetic supporters have been firstly synthesized, followed by the addition of PdCl2 to initial redox reaction between PANI and Pd ions to form Pd nanoparticles on surfaces of Fe3O4/PANI cores, leading to the formation of Fe3O4/PANI/Pd nanoparticle-supported catalysts. The structures of Fe3O4/PANI/Pd nanoparticle-supported catalysts have been confirmed by TEM, energy dispersive X-ray spectroscopic (EDS) elemental mapping analysis, and XPS, and the formation mechanisms have been revealed by FTIR spectra. The catalytic activity of Fe3O4/PANI/Pd nanoparticle-supported catalysts involved in liquid phase reactions have been established through the model catalysis reaction involving reduction of nitroaromatic compounds by NaBH4. Furthermore, their high stability and reactivity for Suzuki cross-coupling reactions of aryl bromides with phenylboronic acids have also been investigated.