Sulfur the archetypal catalyst poison? The sulfur-induced promotion of the bonding of unsaturated hydrocarbons on Cu(111).
We have shown using a combination of temperature-programmed desorption and UV photoelectron spectroscopy that the presence of preadsorbed atomic sulfur promotes the bonding of cyclic unsaturated hydrocarbons (benzene and cyclohexene) to Cu(111). This promoting behavior of sulfur can be rationalized in terms of the ability of adsorbed sulfur to influence the balance between charge donation from the adsorbate to metal, and back-donation from the metal to adsorbate. The effects of sulfur on Cu(111) are dramatically different from those observed in previous studies on Pt(111), which found that it caused a downward shift in the desorption temperature of adsorbed benzene, through purely steric effects.
Rousseau
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GB
Department of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, UK.
Bovet
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N
Kadodwala
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