CO₂ Oxidative Ethane Dehydrogenation on CeO₂/SiO₂‐Supported NiFe₃ Catalysts

Abstract

Abstract CO 2 ‐assisted oxidative dehydrogenation of ethane is a sustainable alternative to steam cracking for ethylene production. In this study, a series of CeO 2 on SiO 2 supported NiFe 3 catalysts were synthesized by incipient wetness impregnation and tested for oxidative dehydrogenation performance. The CeO 2 /SiO 2 supported catalysts with high weight loading of CeO 2 (50%–75%) provided higher activity than the lower CeO 2 (0%–25%) loaded catalysts (with ethylene production rates of 0.62–0.98 µmol/g cat /s and 0.19–0.3 µmol/g cat /s, respectively) while maintaining high ethylene selectivity (43%–45%). In contrast, the NiFe 3 supported on only CeO 2 also exhibited high activity (ethylene production rate of 0.71 µmol/g cat /s), but the ethylene selectivity (16%) was greatly decreased compared to the mixed system. Temperature programmed reduction, X‐ray diffraction, and Raman spectroscopy all indicate the creation of a solid solution of the Fe and Ni doped into the CeO 2 crystal structure in the catalysts with high CeO 2 loading/bulk CeO 2 support. The high ethylene selectivity in the high CeO 2 loading catalysts indicates that the Fe is preferentially creating the solid solution, with the decrease in selectivity observed in the CeO 2 ‐only supported catalyst likely resulting from CeO 2 interacting directly with Ni, creating Ni‐CeO X interfaces that are known active sites for the unwanted side reaction of dry reforming.