Abstract

The influence of excess Fe³⁺ in ZnFe₂O₄ for the catalytic oxidative dehydrogenation of 1-butene to 1, 3-butadiene was investigated to try to clarify inconsistencies in the existing literature. A series of nanoscale zinc ferrite powders were produced with increasing Fe: Zn ratios. The materials were characterized by a range of techniques, which showed the presence of α-Fe₂O₃ as a distinct phase with an increasing excess of Fe³⁺ and SEM highlighted the increased presence of surface structures on the ferrites at higher Fe: Zn ratios. Reaction testing showed α-Fe₂O₃to be virtually inactive for the oxidative dehydrogenation of 1-butene. Results for the ferrite catalysts showed a significant decrease in both conversion and yield with an increasing excess of Fe³⁺. Therefore an excess of Fe³⁺ has a negative effect on catalytic activity and selectivity of zinc ferrite for the oxidative dehydrogenation of 1-butene, but acts as a promoter for competing hydrogenation and combustion side reactions.

Keywords: Zinc ferrite; Oxidative dehydrogenation; Butene; 1.3-butadiene; Iron