The effect of catalyst supports (SiO2, Γ-Al2O3, ZrO2, CeO2, MgO) on the performance of transition metal (Fe, Co, Ni) catalysts for propane dehydrogenation (PDH) with co-feeding of H2S) was investigated. Evaluation of the catalyst activity showed that inert SiO2 is a suitable support for the PDH catalysts. The SiO2-supported Fe catalysts demonstrated the highest activity and selectivity among the evaluated catalysts. To clarify the effect of the support species on the structure and electronic state of the catalyst components, XRD, X-ray absorption fine structure, and X-ray photoelectron spectroscopy (XPS) were employed to characterize the various Fe-loaded catalysts. From Fe K-edge X-ray absorption near edge structure analysis, the catalysts in which Fe was in a higher oxidation state showed better performance for PDH with co-feeding of H2S. When SiO2 and Al2O3 were used as the supports, divalent and trivalent Fe cations were detected by XPS analysis. Such high-valence Fe species could accept an electron from an intermediate species, thus enhancing the dehydrogenation performance.
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