Design of nanostructured palladium catalyst supported by chitosan/CoO microspheres and investigation of its catalytic behavior against synthesis of benzonitriles.

Designing of eco-friendly, low cost, and thermally stable stabilizing/supporting agents are always desired for production of catalyst systems which provide good catalytic performance in organic reactions. In this study, a novel, green, and efficient stabilizer containing chitosan/CoO microspheres (CS/CoO) was developed. Palladium nanoparticles (Pd NPs) were then successfully immobilized on CS/CoO as a heterogeneous nanocatalyst (Pd NPs/CS/CoO). Characterization of the designed materials were performed by FT-IR, TEM, FE-SEM, XRD, and EDS and it was determined that Pd NPs formed as approximately 20 nm. Catalytic behavior of Pd NPs/CS/CoO was investigated in the production of different substituted benzonitriles via aryl halide cyanation. Catalytic studies indicate that electron-rich or poor aromatic halides were smoothly cyanated with good reaction yields by Pd NPs/CS/CoO nanocatalyst by using K[Fe(CN)] as the cyanating agent. Moreover, it was found that Pd NPs/CS/CoO nanocatalyst provided not only good reaction yields and but also good recovery/reusability for six times in the aryl halide cyanations. This paper displays that Pd NPs/CS/CoO nanocatalyst has a great catalytic and recycling potential for aryl halide cyanations.