Environmentally benign synthesis of mesoporous cobaltaluminate nodules as catalyst and its effect on the selective oxidation of benzhydrol to benzophenone

Abstract

Sustainable recycling and disposal of heavy metals present in water is crucial to deprecate harmful effect to the environment. The present work aimed at minimizing this problem by converting heavy metals such as cobalt from its aqueous solution into an effective, reusable, oxidation catalyst like cobaltaluminate. A novel technique has been employed to synthesize mesoporous cobaltaluminate blue spinel nodules by sol-gel route at low temperature. The porous nature of nodules with an appreciable surface area 410 m2/g and excellent dispersion of cobalt into alumina has made it a suitable candidate for catalytic oxidation. The synthesized cobaltaluminate spinal nodules were further employed as an effective catalyst in selective oxidation of benzhydrol to benzophenone with 70% conversion. Important kinetic parameters affecting selective oxidation of benzhydrol to benzophenone have been studied and optimized. The activation energy for the reaction was found to be 13.2 kcal/mol. The nodules were fully characterized by various techniques such as SEM, TEM, BET, XRD and TGA, ToF-SIMS analysis.