Synthesis and Properties of Nanosized Silver Catalyst Supported on Chitosan-Silica Nanocomposites

This work described the immobilization of noble metal nanoparticles on silica microspheres mediated by chitosan. The dual support system is comprised of organic-inorganic materials prepared via core-shell method. Chitosan/silica nanocomposites were successfully synthesized with different chitosan concentrations in order to get the optimized shell thickness. When high concentration of chitosan was employed, it was found that the shell completely coats the silica. The silver nanoparticles were then immobilized on the shell of the support through a sol-gel method. Various quantities of silver were studied in order to get the maximum loading thereby it is related to coating thickness. The catalyst was then tested by employing hydrogenation of cyclohexene in methanol as a model reaction.