AVS 46th International Symposium
    Surface Science Division Friday Sessions
       Session SS2-FrM

Paper SS2-FrM11
Investigation of the Adsorption and Reactions of Thiophene on Sulfided Cu, Mo and Rh Catalysts

Friday, October 29, 1999, 11:40 am, Room 607

Session: Adsorption on Metals and Silicon
Presenter: M.E. Bussell, Western Washington University
Authors: M.E. Bussell, Western Washington University
P. Mills, Western Washington University
D.C. Phillips, Western Washington University
B.P. Woodruff, Western Washington University
R. Main, Western Washington University
Correspondent: Click to Email
Infrared (IR) spectroscopy and temperature programmed desorption (TPD) have been used to investigate the adsorption and reactions of thiophene on alumina-supported sulfided Cu, Mo and Rh catalysts over wide ranges of temperature (130-700 K) and pressure (10 @super-9@ - 10 @super3@ Torr). Following adsorption at 130 K, thiophene adsorbs on sulfided Mo and Rh catalysts in an @eta@@super 1@(S) geometry; it has not been possible to determine the adsorption geometry of thiophene on Cu sites of the sulfided Cu catalyst due to low coverage. The coverage of thiophene on sites in the supported metal sulfide particles is observed to increase in the order Cu < Mo < Rh, in agreement with CO chemisorption measurements. Little or no reactivity is observed when the different catalysts are heated in thiophene vapor alone at temperatures up to 700 K. In thiophene/H@sub 2@ mixtures, hydrogenated species are observed to form on sulfided Rh catalysts by 350 K, and by 550 K on sulfided Mo catalysts. Following evacuation to UHV pressures, TPD shows the major products to be butadiene, butenes and butane. The results of these experiments are in good agreement with flow reactor studies of thiophene hydrodesulfurization over these same catalysts.