Abstract: Carbon-enclosed magnetic nanoparticles synthesized by the hydrothermal method were used as a support for the palladium nanoparticle catalyst. The catalyst samples were characterized by transmission electron microscopy,X-rayphotoelectron spectroscopy, and a vibration sample magnetometer. Its catalytic activity for the Heck coupling reaction was measured. The results showed that the mean catalyst particle size was 300 nm, the surface was covered with a layer of palladium particles (12 nm), and the catalyst was of superparamagnetic property. In the Heck reaction of iodobenzene and acrylic acid catalyzed by the catalyst, high iodobenzene conversion (more than 95%) could be obtained under the base conditions of both CH3COONa and NEt3 after 4 h. The iodobenzene conversion over the catalyst was about 88% after 10 recycles, and the catalyst could be steadily dispersed in the reaction mixture and be separated by the magnetic field added.

Key words: palladium, supported catalyst, magnetic nanocomposite, hydrothermal method, iodobenzene, acrylic acid, Heck reaction