Adsorption and Reaction of Methanethiol on Thin-Film Cerium Oxide

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Surface Science

DOI:https://doi.org/10.1016/j.susc.2008.01.027· OSTI ID:941594

Mullins, David R ^[1]; McDonald, Tom S ^[1]

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1. ORNL

The adsorption and reaction of methanethiol, CH{sub 3}SH, have been studied on cerium oxide thin films that were vapor deposited on Ru(0 0 0 1). The behavior of the CH{sub 3}SH was examined as a function of the Ce oxidation state. CH{sub 3}SH weakly interacts with fully oxidized CeO{sub 2}(1 1 1) forming both chemisorbed CH{sub 3}SH and CH{sub 3}S + OH. OH forms through the reaction of the sulfhydrol H with the surface O. These species recombine and desorb near 180 K leaving the surface virtually clean. When the ceria is ca. 50% reduced, the chemisorbed CH{sub 3}SH desorbs near 150 K while the CH{sub 3}S + OH are stable to 400 K. These species react above 450 K to produce predominantly CH{sub 4} and CH{sub 3}SH. A small amount of CH{sub 2}O and water are also formed through reaction with the O in the ceria. Atomic S is left on the surface. S 2p, C 1s and O 1s soft X-ray photoelectron spectroscopy were used to identify the nature of the chemisorbed species and the adsorption site of the CH{sub 3}S or S.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 941594
• Journal Information: Surface Science, Journal Name: Surface Science Journal Issue: 6 Vol. 602; ISSN SUSCAS; ISSN 0039-6028
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ADSORPTION
CERIUM OXIDES
CHEMICAL COMPOSITION
CHEMISORPTION
DESORPTION
RUTHENIUM
SORPTIVE PROPERTIES
SUBSTRATES
THIN FILMS
THIOLS
VALENCE