Role of disulfide linkages in desulfurization chemistry. The reactions of benzenethiol on a sulfur-covered Mo(110) surface

Journal Article · Wed Sep 07 04:00:00 EDT 1994 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/ja00097a046· OSTI ID:102778

Weldon, M K; Napier, M E; Wiegand, B C; Friend, C M ^[1]; Uvdal, P ^[2]

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1. Harvard Univ., Cambridge, MA (United States)
2. Lund Univ. (Sweden)

The reactions of benzenethiol on a sulfur-covered Mo(110) surface were studied using temperature programmed reaction, X-ray photoelectron, and high resolution electron energy loss spectroscopies. The sulfur overlayer profoundly alters the kinetics and selectivity for desulfurization and dehydrogenation. By using isotopic labeling, we have established that phenyl disulfide (C{sub 6}H{sub 5}S-S-) is formed via S-H bond scission and S-S bond formation on Mo(110) at 100 K. The S-S- linkage is oriented perpendicular and the phenyl ring parallel to the surface. The disulfide subsequently forms an upright phenylthiolate species, bound directly to the Mo(110) surface, prior to the onset of benzene formation at 300 K. In contrast to the clean surface, where only the low-temperature state is observed, a second benzene peak is observed at 500 K on the sulfur-covered surface. This feature is attributed to disproportionation of surface phenyl groups to produce gaseous benzene and surface benzyne. In addition, gaseous phenyl also desorbs from the surface in the same temperature range, due to a lack of available surface hydrogen. The selectivity for gaseous hydrocarbon production is approximately 80%, nearly twice that on the clean surface, while the total amount of reaction remains the same. 40 refs., 5 figs., 2 tabs.

• Sponsoring Organization: USDOE
• DOE Contract Number: FG02-84ER13289
• OSTI ID: 102778
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 18 Vol. 116; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ADSORPTION
AROMATICS
AUGER ELECTRON SPECTROSCOPY
BENZENE
COMPILED DATA
DEHYDROGENATION
DESULFURIZATION
DEUTERIUM COMPOUNDS
LABELLED COMPOUNDS
MOLYBDENUM
ORGANIC SULFUR COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
REACTION KINETICS
SULFUR
ULTRAHIGH VACUUM
X-RAY SPECTROSCOPY