Interaction of Nitrogen and Oxygen on Iron Surfaces
نویسنده
چکیده
Oxygen is a strong poison for the catalytic synthesis of ammonia from Nz + Hz over iron catalysts. On the other hand the formation of nitride in the surface region of iron samples provides protection against corrosion by oxygen. Surface analysis by means of Auger spectroscopy reveals that preadsorption of oxygen blocks the surface sites for dissociative nitrogen chemisorption. If on the other hand a nitrided surface is exposed to oxygen, an oxide layer will be formed and the nitrogen atoms are displaced into the bulk where they cause retardation of further oxide growth. These effects are made plausible on the basis of the energetics of the various steps involved.
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