Co-ETS-10 and Co-AM-6 as active catalysts for the oxidation of styrene to styrene oxide and benzaldehyde using molecular oxygen

Pristine ETS-10 and AM-6 and their Co2＋-exchanged forms were prepared, and their catalytic activi- ties toward the oxidation of styrene in oxygen atmosphere were studied in dimethylformamide. The catalysts were denoted as Co-E10-n （n = 0, 9, 26, 68, 81） and Co-A6-m （m= 0, 8, 23, 63, 79）, where n and rn denote the degree of Co2. exchange. The products of the oxidation process were identified as styrene epoxide （E） and benzaldehyde （B）. Both the pristine forms, ETS-10 （Co-E10-0） and AM-6 （Co-A6-0）, and Co2＋-exchanged forms displayed catalytic activities. With increasing n or m, the con- version, and hence the rate, increased. Specifically, the rates varied from 6.1 to 12.5 mmol·g^-1·h^-1 with increasing n （Co-E10-n catalysts） and from 5.4 to 12.4 mmol·g^-1·h^-1 with increasing m （Co-A6-m catalysts）. In contrast, the E/B ratio decreased with increasing n or m. More specifically, the E/B ratio decreased from 2.1 to 0.1 with increasing n from 0 to 81 （Co-E10-n catalysts） and from 1.3 to 0.1 with increasing m from