ABSTRACT
Stoichiometric oxidants such as permanganate and dichromate are traditionally used in the selective oxidation of hydrocarbons. In the manufacture of large-scale petrochemicals as well as the laboratory-scale syntheses, the environment-unfriendly processes should be replaced with greener catalytic oxidations. Clean, safe, and inexpensive oxidants such as H2O2 and O2 in combination with catalysts can provide useful and safer catalytic oxidation methods [1-10]. In the preceding two decades, many efficient catalytic oxidations in combination with the above-mentioned greener oxidants have been developed [11-24]. However, most of them are homogeneous systems and there are a few excellent heterogeneous catalysts in spite of offering significant advantages from environmental and economical standpoints [1-10]. Oxidations by Ti/SiO2 and TS-1 (titanium silicalite with an MFI structure) are the successful methods [11-14], leading to the development of a variety of heterogeneous oxidation systems with organic hydroperoxide and 30% aqueous H2O2 and much research work on the synthesis of related heterogeneous catalysts for liquid-phase oxidations.
