The roles of ZnFe2O4 and α-Fe2O3 in the biphasic catalyst for the oxidative dehydrogenation of n-butene.

It was speculated that ZnFe 2 O 4 was primarily responsible for activating n-butene and α-Fe 2 O 3 was used to activate O 2. The oxidative dehydrogenation of n-butene over α-Fe 2 O 3 /ZnFe 2 O 4 appeared to be the interface reaction. • ZnFe 2 O 4 was responsible for activating n-butene, α-Fe 2 O 3 was used to activate O 2. • The reaction rates were well correlated with the apparent pre-exponential factor. • Efficient contact between ZnFe 2 O 4 and α-Fe 2 O 3 may lead to improving activity. • ODH of n-butene over α-Fe 2 O 3 /ZnFe 2 O 4 appeared to be the interface reaction. Iron-based catalysts were one of the most effective catalysts in the oxidative dehydrogenation of n-butene, however, the roles of spinel and α-Fe 2 O 3 in the biphasic catalyst have remained controversial. Herein, we found that biphasic catalyst exhibited much superior catalytic performance compared to each individual component. According to the temperature programmed desorption, XPS and kinetics studies results, it was speculated that ZnFe 2 O 4 was primarily responsible for activating n-butene and α-Fe 2 O 3 was used to activate O 2. Moreover, the key factor for the catalytic activity of the biphasic catalyst were investigated and kinetic studies showed that reaction rates were well correlated with the apparent pre-exponential factor. Therefore, the efficient contact between ZnFe 2 O 4 and α-Fe 2 O 3 may lead to the improvement of the activity. In addition, the reaction mechanism over α-Fe 2 O 3 /ZnFe 2 O 4 was proposed to be the interface reaction based on the catalytic evaluation results of substituting ZnFe 2 O 4 by the redox-inactive ZnAl 2 O 4. [ABSTRACT FROM AUTHOR]