| 초록 |
A series of CeO2-MgO oxides with different molar ratio of Ce/Mg were prepared by co-precipitation method. Vanadium oxide in the range 3 - 20 wt% was impregnated on 1Ce-9Mg-O oxide. The catalysts were characterized by N2 sorption, XRD, XPS, 51V MAS NMR, FT-IR, and TPR. Vanadium oxide was finely dispersed up to 10 wt% on 1Ce-9Mg-O support. Isolated VO4 species with vanadium atom in distorted tetrahedral coordination were observed by 51V NMR analyses. The formation of Mg3(VO4)2 which is known as non-active phase in the dehydrogenation of ethylbenzene was observed above 10 wt% V2O5/1Ce-9Mg-O. For the vanadia loading up to 10 wt% the ethlybenzene conversion and the styrene selectivity to styrene were increased to 42 and 93%, respectively, whereas above 10 wt% V2O5 the conversion decreased progressively and the styrene selectivity was still maintained. |
