This study focuses on a novel route for propylene production using a transition metal (Fe, Co, Ni, Mn, Cu) catalyst via propane dehydrogenation (PDH) with co-feeding hydrogen sulfide (H2S). The SiO2-supported Fe (Fe/SiO2) catalyst was found to be highly active and selective for PDH with co-feeding H2S. The Fe/SiO2 catalyst displayed higher stability than the commercial CrOx/γ-Al2O3 catalyst. The durability of the Fe/SiO2 catalyst was tuned by changing the ratio of H2S to propane (H2S/C3) from 0.2 to 2.6: the most stable performance was obtained over the Fe/SiO2 catalyst with a H2S/C3 ratio of below 0.4 for 50 h. The structure of the active site on the Fe/SiO2 catalyst was investigated using XRD, XPS, and XAFS analyses. The co-supplying of H2S promoted formation of an iron sulfide species during the reaction, which was the active site for PDH. The thermodynamic calculations indicate that the iron sulfide active phase was non-stoichiometric, e.g., Fe1–xS. This structure was maintained by co-supplying H2S. DFT calculations of the dehydrogenation path suggest that PDH occurs on an iron sulfide active site via an intermediate of the propyl group combining with the surface sulfide ion.
- Hydrogen sulfide
- Metal sulfide
- Propane dehydrogenation
ASJC Scopus subject areas
- Process Chemistry and Technology