Co-containing molecular sieves, mainly Co–faujasite zeolite and Co-MCM-41, have been studied for the epoxidation of styrene with molecular oxygen. Characterizations with XRD, TEM, laser-Raman, XPS, and H2-TPR suggest that the cobalt introduced into MCM-41 by a template-ion exchange method resembles that exchanged in the faujasite zeolite and exists in the single-site Co(II) state, whereas the sample prepared by the impregnation method contains a large proportion of Co3O4. The Co(II) sites located in the molecular sieves catalyze the epoxidation of styrene by oxygen with higher activity than Co3O4 (ca. 2.6 times based on the same cobalt amount). On the other hand, in homogeneous reactions, Co(NO3)2 and Co(Ac)2 are almost inactive for the conversion of styrene with oxygen, whereas CoCl2 and Co(acac)3 show some activity, but the selectivity for epoxide is remarkably lower as compared with the Co(II)-containing molecular sieves. Among various oxidants examined, oxygen is found to be the best one for the epoxidation of styrene over the Co(II)-containing molecular sieve catalysts. The solvent plays an important role in epoxidation, and superior catalytic performances have been obtained with an acylamide such as N,N-dimethylformamide (DMF) as the solvent. The oxygen species with a radical nature generated by the activation of molecular oxygen over the solvent-coordinated Co(II) site has been proposed for the epoxidation reactions.

Co2+-Exchanged faujasite zeolites can efficiently catalyze the epoxidation of styrene with molecular oxygen, and the Co2+ ions located in supercages are suggested to account for the activation of O2 for the epoxidation of styrene.

Iron phosphate supported on MCM-41 has been studied for partial oxidation of methane with both oxygen and nitrous oxide. Characterizations with XRD, Raman spectroscopy, XPS, and H2-TPR suggest that the supported iron phosphate species with loading amounts lower than 40 wt% are located and dispersed in the mesopores of MCM-41. Such iron phosphate species can be reduced more readily than the unsupported iron phosphate at lower temperatures. Methane is selectively converted to methanol, formaldehyde, and dimethyl ether over the supported and the unsupported iron phosphate with nitrous oxide at milder temperatures (300-500℃), while formaldehyde is mainly produced along with carbon oxides with oxygen at relatively higher temperatures (400-600℃). The supporting of iron phosphate onto MCM-41 with loading amounts of ca. 20-40 wt% increases both methane conversion and overall selectivity to useful oxygenates with either oxygen or nitrous oxide. Kinetic studies indicate that the activation of oxygen occurs rapidly, while the activation of nitrous oxide proceeds at a comparable rate with the conversion of methane by the active oxygen species over both the supported and the unsupported catalysts. The supported catalyst, however, enhances the activation of nitrous oxide and thus remarkably inhibits the carbon deposition occurring over the unsupported iron phosphate.