Improved catalytic properties of Co3O4-impregnated La2O3/MgO over Co3O4/MgO catalyst in the oxidative dehydrogenation of ethylbenzene

A series of lanthanum oxide (La 2 O 3 —2–14 wt%)-encapsulated Co 3 O 4 /MgO catalysts and bare Co/MgO solid oxides were prepared by wetness impregnation method. Among all catalysts, La 2 O 3 -promoted Co 3 O 4 /MgO (CM) was found to be remarkable in terms of superior promotional effect of La oxide species. Therefore, La 2 O 3 -incorporated Co 3 O 4 /MgO (LCM) catalysts afforded unusual catalytic activity efficiency with respect to high EB conversion and styrene selectivity due to the synergistic effect of Co–La species. By contrast, bare Co 3 O 4 /MgO solid oxide (CM) catalyst afforded low EB conversion with mild catalytic activity due to the absence of promotional role of La oxide.