ISSN:
1572-879X
Keywords:
S poisoning
;
Pt sulfidation
;
Cu/Pt and Zn/Pt catalysts
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The interaction of sulfur with Pt(111), Zn/Pt(111) and Cu/Pt(111) has been examined using X-ray photoelectron spectroscopy (XPS), X-ray excited Auger electron spectroscopy (XAES), and thermal desorption mass spectroscopy (TDS). At temperatures between 300 and 600 K, the exposure of Pt(111) to S2 gas produces a chemisorbed layer of sulfurwithout the formation of bulk sulfides. Exposure of S2 to a Zn/Pt(111) alloy, at room temperature, results in a breakdown of the alloy and formation of a zinc-sulfide film on Pt(111). Further S2 exposure at 550 K sulfidizes the remaining metallic zincwithout affecting platinum. For the Cu/Pt(111) surface alloy, on the other hand, exposure to S22 at 550 K leads to sulfidation of the platinum. Platinum can effectively compete for sulfur atoms bonded to copper but not for those bonded to zinc. The reaction of S2 gas with Cu/Pt(111) surfaces produces copper sulfides that promote the sulfidation of Pt by providing surface sites for the dissociation of S2, and by favoring the diffusion of S into the bulk of the system.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00813229
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