Keggin polyoxometalates encapsulated in molybdenum-iron-type Keplerate nanoball as efficient and cost-effective catalysts in the oxidative desulfurization of sulfides

摘要

In this work, the catalytic activity of core-shell-type polyoxometalate (POM) composites, comprised from Keggin POMs encapsulated in Mo_(72)Fe_(30) Keplerate, in the oxidation of various sulfides into corresponding sulfoxides or sulfones and oxidative desulfurization of dibenzothiophene with hydrogen peroxide are investigated. From the results, the catalytic activity of these Keggins encapsulated in Keplerate are better than parent ones and among them BW_(12) ⊂ Mo_(72)Fe_(30) showed the best results. The operationally simple oxidation reactions at room temperature, high to excellent yields and chemoselectivity, short reaction times, and the use of H_2O_2 as oxidant are some of the other advantages in this catalytic system. Also, the synergistic effect of Keggin POMs and Mo_(72)Fe_(30) Keplarate has been confirmed.