Boosting the C–H bond activation in propane dehydrogenation via Fe2O3/GaZrOx interface engineering

Abstract

Propane dehydrogenation (PDH) has emerged as an important on-purpose propene manufacturing route to close the gap between propene production and demand. However, developing environmentally-friendly, cost-effective, and highly active PDH catalysts remains challenging. Herein, a series of Fe₂O₃/Ga_0.2Zr₁O_x catalysts with different Fe loadings were synthesized with the impregnation method. Catalytic test results reveal that the rate of propene formation over Fe₂O₃/Ga_0.2Zr₁O_x first increased and then reached a plateau with the increase of Fe loading. Through kinetic analysis, in situ characterization, and DFT calculations, we identity that there exists a strong interaction between the FeO_x species and Ga_0.2Zr₁O_x support, resulting in the formation of a new active site determined as the interface structure of Fe₂O₃ and Ga_0.2Zr₁O_x with enhanced C–H bond activation ability. Furthermore, the representative 6%Fe₂O₃/Ga_0.2Zr₁O_x catalyst was tested in five reaction–regeneration cycles; although the activity decreases with propane on stream in each cycle due to coke formation, the initial rate of propene formation could be recovered after the regeneration process. It is believed that the presented study may provide some guidance for the practical application of ZrO₂-based catalysts in the PDH reaction.