In Situ EXAFS Studies of Small Fe Particles Used as Catalysts for NH3 Synthesis
Supported Fe particles used as catalysts for ammonia synthesis are studied by X-ray absorption measurements in a newly developed in situ cell under real reaction conditions. Starting with the precursor, various reduction stages and the final reaction conditions at high pressure and high temperature (80 bar, 400°C) have been investigated. The reduction of iron oxide and the growth of Fe particles can be directly observed in the x-ray absorption fine structure. Simultaneously, the activity of the catalyst is measured. A comparison with the absorption fine structure of an iron foil measured at the same temperature gives indications for the size of the small Fe particles in the catalyst.
KeywordsReduction Stage Iron Foil Real Reaction Condition Small Cluster Model
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