Effective utilization of in situ generated hydroperoxide via a Co-SiO2@Ti-Si core-shell catalyst in the oxidation reactions

A core-shell catalyst (Co-SiO2@Ti-Si) with cobalt-based SiO2 nanocomposite (Co-SiO2) as core and Ti-doped mesoporous silica as shell was designed to catalyze a one pot reaction of sulfide oxidation with insitu generated hydroperoxide. The catalyst was characterized by SEM, TEM, UV–Vis, XPS, etc. Compared to Co-SiO2 and the physically mixed one (Co-SiO2+Ti-Si), the core-shell catalyst significantly enhanced the reaction rate of the sulfide oxidation. The utilization efficiency of the hydroperoxide was an important factor attributed to the differences in the reaction rates. Further mechanism study showed the improvement of the efficiency was due to the existence of coordination pathway. The core-shell structure of a bifunctional catalyst represents a strategy to improve the utilization efficiency of hydroperoxide.