Characterization and catalytic activity studies of sol-gel Co-SiO2 nanocomposites

Silica embedded with transition metals exhibits adequate properties for applications in catalysis, sensors and optics. Cobalt-silica (Co-SiO2) nanocomposites were prepared by the sol-gel method and thermally treated at 700, 900, 1100 and 1250 degreesC. Characterization of the samples was performed by XRD and BET nitrogen adsorption. The performance of the nanocomposites was investigated by catalysis reactions of oxidation. These catalysts were found to be recyclable showing a catalytic activity even after a third recovering. The results indicate that thermal treatment of sol-gel nanocomposites at temperatures higher than 900 degreesC is essential for the preparation of active heterogeneous catalysts. (C) 2003 Elsevier Inc. All rights reserved.