Abstract. Over the past decades, a graet attention has been paied to the preparation and utilization of metal nanoparticles (NPs). Aggregations of metal NPs resultes in a remarkable decrease in their applications, and catalytic activities. Therefore, decoration of metal NPs on solid supports is of importance. Due to its unique properties, including biocompatibility, high mechanical stability and easy surface functionalization, polyhedral oligomeric silsesquioxanes (POSS) are considered to be an ideal support for immobilization of metal NPs. Herein, Cobalt nanoparticles decorated on amine functionalized POSS, Co@POSS, was synthesized by hydrolysis of 3-aminopropytriethoxysilane under acidic conditions, followed by impregnation of Co2+ ions, and then reduction to Co nanoparticles. Prepared Co@POSS efficiently catalyzed hydrogenation of nitroaromatic compounds in water. Because, nitroaromatic compounds are considered as water pollutants, removal and conversion of them into useful aniline derivatives is of interest. Methyl, chloro, amino, hydroxy and carboxy substituted nitroaromatics were tolerated under reaction conditions, to give corresponding aniline derivatives within 2-30 min. Synthesized Co@POSS was characterized by XRD, SEM, EDS, and EDS mapping techniques. SEM analysis revealed the aggregation of spherical nanoparticles. In the XRD pattern the formation of POSS nanostructure with Co nanoparticles were concluded. EDS analysis indicated the presence of C, N, O and Si atoms along with the presence of Co, in 8.9% wt% in the structure of Co@POSS.
