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This study investigated 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 hydrogen sulfide (H2S). Evaluation of the catalyst activity indicated that inert SiO2 is a suitable support for the PDH catalysts. The SiO2-supported Fe catalysts showed the highest activity and selectivity among the investigated catalysts. In order to clarify the effect of the support species on the structure and electronic state of the catalyst components, X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), and X-ray photoelectron spectroscopy (XPS) were used to characterize the various Fe-loaded catalysts. From Fe K-edge X-ray absorption near edge structure (XANES) analysis, it is deduced that 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 can accept an electron from an intermediate species, thereby enhancing the dehydrogenation performance.

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Aufgrund ihrer Sauerstoffadsorptionseigenschaften lassen sich die 16 untersuchten Metalloxide in 3 Klassen einteilen: A) V3O5, MoO3, Bi2O3, WO3 und Bi2O3 · 2 MoO3, die im Temp.‐Bereich 10‐560°C keine Sauerstoffdesorption zeigen; B) Cr3O3, MnO2, Fe3O3, Co3O4, NiO und CuO2 die unabhängig von der Präadsorptionsprozedur durchweg große Mengen an Sauerstoff desorbieren; C) TiO2, ZnO2 SnO3, Al2O3 und SiO3 (eine Ausnahme bilden die letzten beiden Oxide), bei denen zwischen 10 und 400°C nur dann Sauerstoff desorbiert wird, wenn vor der Adsorption des 02 bei relativ niedriger Temp. eine Evakuierung bei hoher Temp. vorgenommen wird.