Methanethiol decomposition on Ni(100)

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Langmuir; (United States)

DOI:https://doi.org/10.1021/la00049a023· OSTI ID:5325773

Castro, M E; Ahkter, S; Golchet, A; White, J M ^[1]; Sahin, T ^[2]

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1. Univ. of Texas, Austin (USA)
2. Montana State Univ., Bozeman (USA)

Static secondary ion mass spectroscopy (SSIMS), temperature programmed desorption (TPD), and Auger electron spectroscopy (AES) were used under ultrahigh vacuum conditions to study the decomposition of CH{sub 3}SH on Ni(100). Only methane, hydrogen, and the parent molecule are observed in TPD. Complete decomposition to C(a), S(a) and desorbing H{sub 2} is the preferred reaction pathway for low exposures, while desorption of methane is observed at higher coverages. Preadsorbed hydrogen promoted methane desorption. Upon adsorption, and for low coverages, SSIMS evidence indicates S-H bond cleavage into CH{sub 3}S and surface hydrogen. S-H bond cleavage is inhibited for high coverages. The TP-SSIMS data are consistent with an activated C-S bond cleavage in CH{sub 3}S, with an activation energy of 8.81 kcal/mol and preexponential factor of 10{sup 6.5}s{sup {minus}1}. The low preexponential factor is taken as indicating a complex decomposition pathway. A mechanism consistent with the observed data is discussed.

• OSTI ID: 5325773
• Journal Information: Langmuir; (United States), Journal Name: Langmuir; (United States) Vol. 7:1; ISSN 0743-7463; ISSN LANGD
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ACTIVATION ENERGY
ALKANES
AUGER ELECTRON SPECTROSCOPY
CATALYTIC EFFECTS
CHEMICAL REACTIONS
DATA
DECOMPOSITION
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
MASS SPECTROSCOPY
METALS
METHANE
NICKEL
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
SPECTROSCOPY
THIOLS
TRANSITION ELEMENTS
ULTRAHIGH VACUUM