Mechanism of HDS/HDN reactions

Conference · Fri Jan 01 00:00:00 EST 1993

OSTI ID:6562955

Mullins, D R; Lyman, P F

One method for exploring the mechanisms involved in HDS/HDN reactions is to study the elementary reaction steps that occur for model systems using UHV surface science techniques. Our approach has been to examine reactions involving a prototypical organosulfur molecule, methanethiol, adsorbed on different clean and modified metal surfaces. In general, as the surface is heated, this molecule follows two principle reaction pathways on most transition metal surfaces. At low coverages, the molecule undergoes total decomposition producing adsorbed atomic sulfur and carbon and gaseous H[sub 2]. At higher coverages a competing pathway results in adsorbed sulfur and gaseous methane. In order to understand these reactions, the different chemical intermediates are identified, and the differences in reactivity for these intermediates are studied as a function of adsorbate coverage, surface composition and sample temperature. Several analytical techniques are employed in these experiments. Temperature programmed desorption, TPD, is used to identify the desorbed reaction products, their desorption temperature and the branching ratio as the system is modified. Auger electron spectroscopy, AES, is used to determine the amount of adsorbed atomic species that result from the reaction. The reaction intermediates are studied by high resolution soft x-ray photoelectron spectroscopy.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6562955
• Report Number(s): CONF-930802-1; ON: DE93011858
• Resource Relation: Conference: 206. American Chemical Society national meeting, Chicago, IL (United States), 22-27 Aug 1993
• Country of Publication: United States
• Language: English

Related Subjects

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COAL LIQUIDS
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DESULFURIZATION
ORGANIC SULFUR COMPOUNDS
DECOMPOSITION
TRANSITION ELEMENT COMPOUNDS
CATALYTIC EFFECTS
AUGER ELECTRON SPECTROSCOPY
CHEMICAL REACTION KINETICS
DESORPTION
HYDROGENATION
REACTION INTERMEDIATES
CHEMICAL REACTIONS
ELECTRON SPECTROSCOPY
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SORPTION
SPECTROSCOPY
010405* - Coal
Lignite
& Peat- Hydrogenation & Liquefaction