J. Roberts, C. Friend
Nov 12, 1986
Citations
0
Influential Citations
72
Citations
Quality indicators
Journal
Journal of the American Chemical Society
Abstract
The reactions of tetrahydrothiophene and 1-butanethiol on Mo(110) have been investigated by using temperature-programmed reaction spectroscopy, isotopic exchange reactions, and Auger electron spectroscopy. At low exposures, tetrahydrothiophene decomposes below 400 K to gaseous dihydrogen and surface carbon and sulfur. Higher tetrahydrothiophene exposures also result in reaction limited formation of butane and butene at 350 and 380 K, respectively. Preadsorption of a saturation coverage of hydrogen or deuterium atoms decreases the temperature at which butane is formed by 50 K and increases the yield of butane by a factor of approximately 6 at reaction saturation. The butene formation peak is unaffected by the presence of excess surface hydrogen. Reversible desorption of molecularly bound tetrahydrothiophene from the Mo(110) surface is observed at 310 K. In the absence of preadsorbed hydrogen, approximately 25% of the tetrahydrothiophene that reacts forms hydrocarbons, as measured by Auger electron spectroscopy. An irreversibly bound hydrocarbon fragment is present on the surface which decomposes at 565 K to produce gaseous dihydrogen. The butane, butene, and dihydrogen incorporate surface deuterium. The proposed mechanism for this reaction is initial hydrogenation of one of the ..cap alpha..-carbon atoms with accompanying C-S bond scission.