Effects of iron content on bismuth molybdate for the oxidative dehydrogenation of n-butenes to 1,3-butadiene

摘要

BiMoFe_x oxide catalysts (x = 0-1.00) were prepared by co-precipitation and their catalytic activities in the oxidative dehydrogenation of n-butenes were tested. X-ray diffraction (XRD) and Raman spectroscopy showed that the main solid phases were composed of Bi3Mo2FeO_(12) as oxygen acceptor and Fe2(MoO4)3 as oxygen donor and the mixing of these phases enhanced catalytic activity. XRD patterns showed that Fe2(MoO4)3 was reduced to FeMoO4 during the reaction. The peak temperature of programmed reduction of 1-butene and successive oxidation (TPRO) was dependent on Fe contents in BiMoFe_x oxide catalysts and was minimized at x = 0.65, which showed the greatest oxygen mobility. The peak position in the low temperature region of TPRO profiles could be correlated with butene conversion and BD yield.