Preparation of ZnFe2O4 catalysts by a co-precipitation method using aqueous buffer solution and their catalytic activity for oxidative dehydrogenation of n-butene to 1,3-butadiene

Zinc ferrite (ZnFe2O4) catalysts were prepared by a co-precipitation method using aqueous buffer solution with different pH (pH = 6-12), and applied to the oxidative dehydrogenation of n-butene to 1,3-butadiene. Conversion of n-butene and yield for 1,3-butadiene showed volcano-shaped curves with respect to pH value employed during the co-precipitation step. NH3-TPD experiments were conducted to correlate the acid property with the catalytic performance of zinc ferrite catalysts. It was revealed that the catalytic performance of zinc ferrite catalysts in the oxidative dehydrogenation of n-butene was closely related to the surface acidity of the catalysts. Conversion of n-butene and yield for 1,3-butadiene increased with increasing surface acidity of the catalysts. Among the catalysts tested, the zinc ferrite catalyst prepared at pH = 8 showed the best catalytic performance in the oxidative dehydrogenation of n-butene, which was attributed to its largest surface acidity.